Publication abstracts about spinal CSF leak from 2025

AUTHORS: Fides R Schwartz, Raymond Y Huang, Matthew N DeSalvo, Jason R Lauer, Shuhan Zhu, Rose L Wach, Aaron D Sodickson, Neel Madan

CITATION: AJNR. American journal of neuroradiology, ajnr.A9151. 24 Dec. 2025, doi:10.3174/ajnr.A9151

BACKGROUND AND PURPOSE: CSF leaks are difficult to detect with energy-integrating (EID) CT myelography due to its limitation in spatial resolution. The purpose of this study was to develop a streamlined protocol for entire-spine-evaluation for CSF leaks in patients with spontaneous intracranial hypotension using photon-counting CT (PCCT).

MATERIALS AND METHODS: In this IRB-approved study, 35 patients (25 women, mean age: 51.6±15.6 years) with prior inconclusive spine imaging for CSF-leak detection received PCCT myelographic imaging. Contrast was injected under fluoroscopic guidance, and patients were transported to the PCCT scanner in decubitus positioning. PCCT was performed with a protocol minimizing patients’ time in the scanner to 15 minutes, while acquiring full spine images at 0.2×0.1 mm resolution in three breathing phases: resistive inspiration, end inspiration and Valsalva (six series total). All but two patients had imaging performed on two consecutive days, once for each decubitus position.The number of CT/MRI investigations and blood patches prior to the PCCT were documented for each patient. One neuroradiologist with subspecialty training in spinal interventions assessed each PCCT to define whether a CSF leak was identified. Three separate readers assessed best breathing phase for leak detection. Treatment was considered a success if patients received an intervention that provided symptom relief.

RESULTS: Patients had received 4.6±5.0 prior CTs (range: 0-26) and 4.0±3.0 prior MRIs (range: 1-13); this had led to a mean of 2.1±1.3 prior blood/fibrin glue patches (range: 1-6) without lasting symptom relief.A CSF leak was definitively identified in 12/35 (34%) patients; an additional 8/35 (23%) patients had potential CSF leak sites. Following PCCT imaging, four patients received surgical treatment, eight received percutaneous embolization and 17 received blood/fibrin glue patches. Resistive inspiration was most frequently considered the best phase for leak detection. Of patients who underwent treatment, it was considered a success in 18/29 (62%) patients, 5/29 (17%) had no relief, 6/29 (21%) had incomplete relief and six patients had not been treated at the time of last follow-up.

CONCLUSIONS: Using a streamlined PCCT protocol, CSF leak detection is feasible and provides diagnosis allowing targeted treatment options for patients whose prior imaging was inconclusive.

PMID: 41444114  
DOI: 10.3174/ajnr.A9151

AUTHORS: Cara Campbell, Daniel Montes, Debayan Bhaumik, Peter Lennarson, Andrew L Callen

CITATION: AJNR. American journal of neuroradiology, ajnr.A9138. 12 Dec. 2025, doi:10.3174/ajnr.A9138

BACKGROUND AND PURPOSE: Meningeal diverticula are commonly seen on spine imaging, but their relationship to cerebrospinal fluid (CSF) leak remains debated. A prior study found no association with spontaneous intracranial hypotension (SIH), but this predated recognition of CSF venous fistulas (CVF). We re-examined this question, hypothesizing that greater diverticula burden is associated with a higher rate of CVF on myelography. Secondary aims included exploring associations with age, sex, and connective tissue disease (CTD).

MATERIALS AND METHODS: Spine MRIs of 42 consecutive patients who underwent dynamic myelography for suspected CVF (April 2024-January 2025) were reviewed; those without 3D T2 fat-suppressed MRI were excluded. Diverticular size and number were quantified, and CVF presence on myelography was recorded. Associations were examined using parametric and non-parametric tests, trend analyses, and age-and sex-adjusted logistic regression models.

RESULTS: Patients with definite CVF had significantly larger (mean 8.2 vs 4.7 mm, p=0.009) and more diverticula (median 21 vs 9, p=0.03). Nonparametric trend testing further confirmed stepwise increases in both diverticular number (Spearman’s ρ=0.44, p=0.005) and size (ρ=0.37, p=0.02). Patients with definite CVF were significantly older than controls (mean 62.6 vs 48.3 years, p=0.001). Adjusted analyses including age and sex showed borderline associations with diverticular size (OR 1.20, 95% CI 1.00-1.43, p=0.05) and number (OR 1.06, 95% CI 0.99-1.13, p=0.09); age remained an independent predictor in both models. No associations were observed with sex or CTD.

CONCLUSIONS: Both the number and size of diverticula were associated with the presence of CVF, challenging assumptions that diverticula are incidental in SIH and suggesting that diverticular burden may offer supportive information when evaluating patients for suspected CVF, while recognizing that age exerts a strong influence on both diverticular burden and CVF status.

PMID: 41386989 
DOI: 10.3174/ajnr.A9138

AUTHORS: Peter G Kranz, Timothy J Amrhein, Waleed Brinjikji, Andrew L Callen, Ian Carroll, J Levi Chazen, Jeremy Cutsforth-Gregory, Deborah I Friedman, Troy A Hutchins, Vance T Lehman, Ajay A Madhavan, Mark D Mamlouk, Ian T Mark, Marcel M Maya, Franklin G Moser, Simy K Parikh, Wouter I Schievink, Lubdha M Shah, Vinil N Shah, Ashesh A Thaker, John E Jordan

CITATION: AJNR. American journal of neuroradiology vol. 46,12 2457-2467. 4 Dec. 2025, doi:10.3174/ajnr.A9017

ABSTRACT: Diagnostic imaging of the brain and spine in spontaneous intracranial hypotension (SIH) has evolved rapidly in the past several years, presenting challenges for practitioners seeking to stay current on the optimal methods for investigating and localizing spinal CSF leaks. We established a Guidelines Working Group with representation from experts in diagnostic imaging as well as external experts in the clinical management of SIH. Recommendations and statements addressing the selection and performance of diagnostic imaging in patients with known or suspected SIH were developed by using a modified Delphi process. The intent was to provide guidance across a variety of practice settings in North American health care systems to implement current best practices in the diagnostic evaluation of SIH.

PMID: 41266257  
PMCID: PMC12687982 (available on 2026-12-01)  
DOI: 10.3174/ajnr.A9017

AUTHORS: Derrek Schartz, Peter G Kranz, Michael D Malinzak, Jay Willhite, Ajay A Madhavan, Linda Gray, Timothy J Amrhein

CITATION: AJNR. American journal of neuroradiology, ajnr.A9119. 24 Nov. 2025, doi:10.3174/ajnr.A9119

BACKGROUND AND PURPOSE: Post dural puncture headache (PDPH) refractory to conservative measures can be clinically debilitating, and diagnostic evaluation with spinal imaging including CT myelography (CTM) may be performed to localize a CSF leak and guide treatment. The purpose of this study is to determine the diagnostic yield of CTM for detecting a CSF leak in patients with persistent PDPH.

MATERIALS AND METHODS: This is a single center, retrospective cohort study of patients referred for CTM between September 2013 to August 2025 to localize and/or identify a CSF leak in patients with PDPH. Brain MRIs were categorized as either positive or negative for findings of intracranial hypotension. CTMs were categorized as either positive or negative for the presence of a CSF leak or arachnoid bleb. The overall rate of CTM positivity in PDPH patients was calculated. Logistic regression analysis was used to investigate variables that were associated with positive CTM.

RESULTS: A total of 118 PDPH patients were included in the analysis (81% female, mean age of 40 +/-12 years). Brain MRIs were negative for findings of intracranial hypotension in 92% of cases. Overall, CTM was positive in only 7 cases (5.9%, 7/118). Four were extradural fluid collections consistent with a CSF leak, and 3 were arachnoid blebs at the site of prior dural puncture. In three positive cases where both spine MRI and CTM available, the abnormality was also seen on MRI in two cases. On logistic regression, only a positive brain MRI was independently associated with a significantly higher odds of a positive CTM (OR 12.6 [CI: 1.8 to 90]; P=0.012).

CONCLUSIONS: CTM has a low diagnostic yield in patients with PDPH, uncommonly identifying specific leak related findings. Because CTM necessarily involves repeat dural puncture, and given this low yield, it should be used sparingly in patients with refractory PDPH, especially when signs of intracranial hypotension are absent on brain MRI. As some findings on CTM are also seen on spinal MRI, which is noninvasive, further research is needed to compare the yield of MRI and CTM to determine whether and when CTM provides additional diagnostic information in this population.

PMID: 41285545 
DOI: 10.3174/ajnr.A9119

AUTHORS: Tony Zhang, Sara J Hooshmand, Nathaniel P Rogers Jr, David O Sohutskay, Michel Toledano, Derek W Stitt, Ivan D Carabenciov, Ajay A Madhavan, Jeremy K Cutsforth-Gregory, Rafid Mustafa

CITATION: The Neurohospitalist, 19418744251399726. 16 Nov. 2025, doi:10.1177/19418744251399726

BACKGROUND: Spontaneous intracranial hypotension (SIH) results from cerebrospinal fluid (CSF) leakage due to spinal dural tears or CSF-venous fistulas. Orthostatic headache is the hallmark presentation, though severe downward displacement of the brainstem may lead to altered consciousness or coma. Definitive treatments include targeted epidural blood patches, venous embolization, or surgical repair.

METHODS: This article reviews the role of the Trendelenburg position as a temporizing measure in the acute management of SIH. We describe the correct technique, physiologic rationale, and practical considerations for its application, with attention to both therapeutic and diagnostic utility.

DISCUSSION: Positioning the patient with the feet elevated above the head can reduce brain sag and provide short-term symptomatic relief while awaiting definitive treatment. Although the Trendelenburg position is widely used in practice, supporting evidence remains limited, and clinicians must be aware of its benefits, indications, and inherent limitations. Its appropriate application may assist in stabilizing patients with acute or severe SIH, particularly those with impaired consciousness, until more definitive interventions are pursued.

PMID: 41262869  
PMCID: PMC12623224  
DOI: 10.1177/19418744251399726

AUTHORS: Joshua Loewenstern, Pierce McMahon, Usama Sattar, Andrew D Schweitzer, Sara Strauss, Gayle Salama 

CITATION: Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences, 15910199251399738. 25 Nov. 2025, doi:10.1177/15910199251399738

BACKGROUND: Epidural contrast extravasation (ECE) at the level of lumbar puncture site during CT myelography (CTM) is a noted phenomenon without determined clinical relevance. While prior randomized studies in spinal analgesia have shown benefits of pencil-type spinal needles compared to cutting-type for dural punctures, rates of ECE on imaging have not been closely studied, and no prior study has investigated the effect of spinal needle type technical factors on ECE rate.

METHODS: All CTM cases over an 8-year period for any indication (e.g., spontaneous intracranial hypotension CSF leak evaluation) were retrospectively reviewed. A large series of cases (n = 276) were reviewed by two independent neuroradiologists for presence of puncture site ECE (n = 63), ECE extending at least one vertebral body level (n = 15), or no ECE (n = 198). Rates were compared by several technical factors including spinal needle type, gauge, and puncture site level.

RESULTS: Pencil-type spinal needles had significantly greater rates of any ECE (32%) versus cutting-type (25%, p = 0.030) and for ECE at puncture site only (25% vs. 20%, respectively) and ECE with extension greater than one vertebral body level (7% vs. 4%, respectively, p = 0.004). The rate of ECE did not differ by needle gauge, needle type/gauge combinations, or level accessed (p > 0.05). The need for post-dural puncture targeted epidural blood patch did not differ by presence of ECE (p = 0.190).

CONCLUSIONS: The rate of ECE in CTM was common (28% of cases) and occurred with slightly greater frequency with pencil-type spinal needles. As CTM and the use of pencil-type spinal needles become more prevalent in the investigation of spinal CSF leak, it is important to convey that asymptomatic ECE can be a common expected post-dural puncture finding with both pencil-type and cutting-type spinal needles and should not be confused for the site of leak when evaluating patients for spontaneous spinal CSF leak. Further, our results that immediate ECE do not correlate with symptomatic post-dural puncture headache differ from a recent retrospective series, and the imaging finding alone of ECE does not warrant further evaluation in an asymptomatic patient.

PMID: 41289223  
PMCID: PMC12646956
DOI: 10.1177/15910199251399738

AUTHORS: Pedro David Delgado-López, Ane Barreras-García, Ana Sabel Herrero Gutiérrez, Antonio Montalvo-Afonso, Rubén Diana Martín, Javier Martín-Alonso, Vicente Martín-Velasco

CITATION: Neurosurgical review vol. 49,1 4. 15 Nov. 2025, doi:10.1007/s10143-025-03917-z

🔓Open access! Full study available here.

ABSTRACT: Cerebrospinal fluid (CSF) leakage is a significant complication following planned or incidental durotomies during spinal surgery. While primary suturing remains the gold standard for dural closure, it is common to necessitate adjunctive reinforcement techniques. This study aims to evaluate the efficacy of a synthetic collagen-based sealant patch (TachoSil®) in preventing CSF leaks in a large cohort of patients undergoing spinal surgery. A retrospective analysis was conducted in whom TachoSil® was used as a dural sealant, either following planned (n = 12) or incidental (n = 42) durotomies, or prophylactically (n = 31) after decompression for critical lumbar canal stenosis. The primary endpoint was the prevention and resolution rate of CSF leaks. Secondary endpoints included reoperation rates and postoperative complications. A total of 85 patients (6.8%) met the inclusion criteria (mean age, 64.7 ± 15.4 years). TachoSil® was used as monotherapy in 39 patients and in combination with primary suturing or other sealants in 46 patients. Overall, 66 patients (77.6%) did not require surgical reintervention. TachoSil® monotherapy was associated with a significantly higher success rate (89.7%) compared to combined techniques (68.2% for TachoSil® plus suturing and 60.0% for TachoSil® plus other sealants; p = 0.041). Excluding its prophylactic use (either planned or incidental durotomy, n = 54), its efficacy in avoiding reintervention was 86.7% for TachoSil® alone, 77.3% for TachoSil® plus suture, and 64.7% for TachoSil® plus other combinations of sealants (p = 0.67). Postoperative complications occurred in 22 patients (25.9%), primarily including persistent CSF fistula, pseudomeningocele formation, and surgical site infections. TachoSil® demonstrated high efficacy as a standalone dural reinforcement method and when combined with suture or other sealant techniques in preventing CSF leaks following spinal surgeries involving dural compromise.

PMID: 41240180
PMCID: PMC12619807
DOI: 10.1007/s10143-025-03917-z

AUTHORS: Taruna Agrawal, Jhia Jiat Teh, Konstantinos S Kechagias, Zak Jefferson-Pillai, Kanwaljeet Kaur Sandhu, Sarah-Jane Lam

CITATION: Reports (MDPI) vol. 8,4 231. 11 Nov. 2025, doi:10.3390/reports8040231

🔓Open access! Full study available here.

BACKGROUND AND CLINICAL SIGNIFICANCE: Spontaneous intracranial hypotension (SIH) is a rare cause of headache characterised by cerebrospinal fluid (CSF) leakage, with an estimated incidence of 3.7 to 5 cases per 100,000 per year, peaking around the age of 40 years. Its diagnosis and management are particularly challenging in pregnancy due to overlapping symptoms and limited diagnostic options. 

CASE PRESENTATION: We report the case of a 42-year-old pregnant woman at 14 weeks of gestation presenting with a history of orthostatic headache and facial sinus tenderness, later diagnosed as spontaneous intracranial hypotension. 

CONCLUSIONS: Headache is a common clinical symptom that may be associated with a wide spectrum of underlying conditions, ranging from benign causes such as migraine or tension-type headache to potentially life-threatening pathologies, including subarachnoid haemorrhage. This case illustrates the diagnostic complexity of SIH in pregnancy and the importance of a multidisciplinary approach and vigilance for neurological symptoms during pregnancy.

PMID: 41283599  
PMCID: PMC12643453
DOI: 10.3390/reports8040231

AUTHORS: Derrek Schartz, Peter G Kranz, Timothy J Amrhein, Jay Willhite, Linda Gray, Michael D Malinzak, Nicholas T Befera

CITATION: AJNR. American journal of neuroradiology, ajnr.A9080. 6 Nov. 2025, doi:10.3174/ajnr.A9080

BACKGROUND AND PURPOSE: Cerebrospinal fluid-venous fistulas (CVF) are a common cause of spontaneous intracranial hypotension (SIH) and can be treated with transvenous embolization (TVE). Rebound intracranial hypertension (RIH) is an important periprocedural consideration after TVE and CSF leak closure. The purpose of this study was to determine the incidence and severity of post-procedure RIH among patients with CVFs treated with TVE.

MATERIALS AND METHODS: This investigation was a single center, retrospective cohort of consecutive patients treated with TVE for SIH due to a CVF. Patients were included who had early (1-3 days post-TVE procedure) clinical follow-up documenting presence/severity of RIH. RIH was classified as absent, mild (i.e. rated 1-4/10 in severity), moderate (i.e. rated 5-7/10), or severe (i.e. rated 8-10/10). Rate of RIH was then determined. Logistic regression analysis was used to evaluate for clinical predictors of moderate-to-severe RIH and need for eventual therapeutic lumbar puncture (LP).

RESULTS: In total, 100 consecutive patients (mean age, 59.4 years old, 63% female) who underwent 105 TVE procedures for 132 CVFs were included. RIH of any severity (mild to severe) occurred in 80% of cases after TVE and was moderate-to-severe in 54% of cases. A therapeutic LP was needed for RIH in 8 cases (7.6%). On multivariate regression, TVE of a single CVF (versus >1 CVF) was independently associated with occurrence of moderate-to-severe RIH (OR: 2.8 [CI: 1.04 to 7.85], p=0.04). Furthermore, higher pre-TVE opening pressure (third tertile, 17-28 cmH2O) was associated with eventual need for therapeutic LP (OR: 5.0 [CI: 1.14 to 25.9], p=0.03).

CONCLUSIONS: Early RIH is common after TVE, with symptoms occurring in 80% of all cases. Approximately half of patients will experience moderate-to-severe RIH early after TVE. These findings underscore the value of routine early follow-up after TVE and emphasize the need for proceduralists to be familiar with management strategies for RIH.

PMID: 41198227  
DOI: 10.3174/ajnr.A9080

AUTHORS: Soyoun Choi, Michelle Sojung Youn, Young Hun Jeon, Mi Ji Lee

CITATION: J Clin Neurol. 2025;21(6):557-564. doi:10.3988/jcn.2025.0154

🔓Open access! Full study available here.

BACKGROUND AND PURPOSE: Diagnosing spontaneous intracranial hypotension (SIH) remains a clinical challenge. The Bern score offered a structured scoring system for estimating the probability of spinal extradural cerebrospinal fluid leaks. We aimed to validate the Bern score in an East Asian cohort from a headache clinic.

METHODS: Patients with SIH were recruited from 2022 to 2023, and age- and sex-matched controls with primary headache and normal brain MRI were included. All SIH patients underwent brain MRI and spine MR myelography before epidural blood patch. The Bern score was assessed and validated by two neurologists and one neuroradiologist. We evaluated its diagnostic performance with a receiver operating characteristic (ROC) curve and visualized the temporal profile of Bern scores using a LOESS (locally weighted scatterplot smoothing) graph.

RESULTS: A total of 45 patients with SIH and 45 age-sex-matched controls were included. The ROC curve showed moderate diagnostic accuracy (area under the curve 0.775, 95% confidence interval 0.675-0.874; sensitivity 42.2%, specificity 95.6%) using the original cutoff of 3. Using a revised cutoff was ≥2, the Youden index was highest (sensitivity 66.7%, specificity 84.4%, accuracy 75.6%). Still, its performance remains suboptimal. The Bern score declined after 50 days from symptom onset.

CONCLUSIONS: The Bern score showed high specificity but limited sensitivity in our cohort, indicating it should not be used alone as a screening tool. A lower cutoff may improve its diagnostic performance, and timing from symptom onset should be considered when interpreting the score.

PMID: 41151933  
PMCID: PMC12569410  
DOI: 10.3988/jcn.2025.0154

AUTHORS: Ajay A Madhavan, Michelle L Kodet, Lalani Carlton Jones, Federico Cagnazzo, Jurgen Beck, Niklas Lutzen

CITATION: AJNR. American journal of neuroradiology, ajnr.A9071. 29 Oct. 2025, doi:10.3174/ajnr.A9071

ABSTRACT: Lateral dural tears are a common cause of spontaneous intracranial hypotension. Frequently, these leaks are associated with an arachnoid diverticulum that herniates through the dural defect. CSF egress into the epidural space occurs from the margins of the dural tear rather than from the lateral portion of the herniated arachnoid diverticulum. Nonetheless, arachnoid diverticula can have secondary effects that alter the physiology and imaging appearance of lateral leaks. Specifically, we have anecdotally observed three unique variations of lateral dural tears, including 1) lateral dural tears where the herniated arachnoid diverticulum is associated with a CSF leak that involves the facet joint, 2) lateral tears where the arachnoid diverticulum is associated with a CSF-venous fistula and 3) lateral tears where there is contrast leaking into the epidural space on decubitus myelography without evidence of epidural CSF collections on pre-procedural spine MRI. In this clinical report, we describe a multiinstitutional retrospective case series of patients harboring these unique variations of lateral dural tears. We sought to elucidate the clinical and imaging features of these patients.

PMID: 41161867  
DOI: 10.3174/ajnr.A9071

AUTHORS: Danial Nasiri, Theoni Maragkou, Bastian Dislich, Levin Häni, Johannes Goldberg, Eike I Piechowiak, Tomas Dobrocky, Jürgen Beck, Andreas Raabe, Ralph T Schär

CITATION: Neurosurg Spine. Published online October 24, 2025. doi:10.3171/2025.7.SPINE25497

OBJECTIVE: Spontaneous intracranial hypotension (SIH) with a ventral CSF leak (type 1) is believed to be caused by discogenic microspurs. Recently, this hypothesis was questioned, in which Hofmann’s ligament, a fibrous connective tissue between the dura and posterior longitudinal ligament, was claimed to be the cause of a spinal dural tear. The primary objective of this study was to determine whether SIH type 1 lesions arise from a discogenic source or from fibrotic tissue.

METHODS: Patients with ventral CSF leaks treated at the authors’ institution, in whom histopathological reports on microspurs were available, were included. All histopathological analyses were repeated and tissues classified into either a fibrotic (Hofmann’s ligament) or discogenic group. Correlation analysis of microspur localization in the spine and their origin was conducted. Microspur length and Hounsfield units (HUs) on CT were compared between both groups.

RESULTS: Twenty-seven patients (19 women, 8 men) with a median age of 57 (IQR 46-64) years were analyzed. Nine microspurs were identified originating from fibrous tissues (Hofmann’s ligament) and 13 microspurs were of discogenic origin, while 5 microspurs could not be classified into either group. Nine microspurs were found at the cervicothoracic or thoracolumbar junction, while 18 were located within the midthoracic spine. The location of the microspurs did not correlate with the histopathological origin of the microspur (p = 0.29). The length of a microspur (p = 0.29) as well as its density measured in HUs (p = 0.90) did not show a statistically significant difference between the fibrous and discogenic groups.

CONCLUSIONS: These findings confirm that microspurs in patients with ventral CSF leaks originate from both the intervertebral disc and fibrous epidural ligament, suggestive of Hofmann’s ligament.

PMID: 41135115  
DOI: 10.3171/2025.7.SPINE25497

AUTHORS: Simy K Parikh, Constance R Deline, Morgan McCreary, Farnaz Amoozegar, Tim J Amrhein, Ian R Carroll, Jeremy K Cutsforth-Gregory, Linda G Leithe, Peter G Kranz, Charles Louy, Marcel M Maya, Abhay Moghekar, Jill Rau, Stephen Silberstein, Wouter I Schievink, Deborah I Friedman

CITATION:  Headache. Published online October 15, 2025. doi:10.1111/head.15060

⭐ The Spinal CSF Leak Foundation helped fund this research. ⭐

OBJECTIVE: The objective of this study was to summarize the available evidence regarding the clinical value and trend over time of lumbar cerebrospinal fluid (CSF) opening pressure utilization to diagnose spontaneous intracranial hypotension (SIH).

BACKGROUND: CSF opening pressure obtained via lumbar puncture is one of the diagnostic criteria for SIH based on the International Criteria for Headache Disorders, 3rd Edition (ICHD-3), but it has questionable utility as an initial investigation for diagnosing SIH.

METHODS: The authors performed a systematic literature review and meta-analysis. PubMed/MEDLINE, Scopus, and Cochrane Library were searched from inception to October 2022. Original studies and case series in English reporting three or more patients with suspected or known SIH and CSF pressure measurement were included. Meta-analyses and meta-regression were used to calculate pooled estimates and examine the impact of age, sex, and publication year on outcomes, including CSF pressure < 60 mm CSF, orthostatic headache, and positive findings on brain magnetic resonance imaging (MRI), spinal imaging, and radionuclide studies.

RESULTS: For every 1-year increase in the year of publication, the odds of reporting low CSF pressure decreased by 6.20% (adjusted odds ratio [aOR] = 0.94, aOR 95% confidence interval [CI] = [0.90, 0.97], p = 0.001), the odds of reporting a positive brain MRI increased by 4.67% (aOR = 1.05, aOR 95% CI = [1.01, 1.09], p = 0.026), and the odds of reporting orthostatic headache increased by 9.13% (aOR = 1.09, aOR 95% CI = [1.03, 1.15], p = 0.002). Each 1% increase in the percentage of patients with orthostatic headache was associated with a 3.13% increase in the odds of low CSF pressure (aOR = 1.03, aOR 95% CI = [1.01, 1.05], p = 0.003). Similarly, as the percentage of patients with low CSF pressure increased by 1%, there was a 2.53% increase in the odds of orthostatic headache (aOR = 1.03, aOR 95% CI = [1.01, 1.04], p = 0.005). It was estimated that 31.9% of patients with SIH had normal opening pressure (95% CI = [24.0%, 40.8%], prediction interval = [5.0%, 80.5%]). Every 1% increase in the percentage of patients with positive brain MRI was associated with a 5.25% increase in the odds of positive spinal imaging (aOR = 1.05, aOR 95% CI = [1.00, 1.11], p = 0.047). Age and positive radionuclide study did not significantly impact the outcomes measured. The corresponding I2 for each outcome was reduced by controlling for study-wide covariates believed to impact the prevalence of each outcome. Sensitivity analyses did not reveal discrepancies in results when studies requiring outcomes of interest were removed.

CONCLUSION: Our analysis found that recent studies indicate a reduced reliance on opening pressure for diagnosing SIH. Rather, results suggest an increasing reliance on contrast-enhanced brain MRI, spine imaging, and clinical features for SIH diagnosis.

PMID: 41090555 
DOI: 10.1111/head.15060

AUTHORS: Federico Cagnazzo, Anne Ducros, Nicolas Lonjon, Francois-Louis Collemiche, Emmanuelle Le Bars, Liesjet E H van Dokkum, Vincent Costalat, Antonio Marrazzo  

CITATION: J Neurointerv Surg. Published online October 15, 2025. doi:10.1136/jnis-2025-023993

BACKGROUND: Navigating the epidural plexus (EP) is a key step in transvenous embolization of cerebrospinal fluid-venous fistulas (CSFVFs) in spontaneous intracranial hypotension (SIH). However, no standard venographic classification currently exists to predict procedural complexity. This study proposes a venographic classification of the EP and evaluates its correlation with technical outcomes.

METHODS: From November 2022 to May 2025, 85 patients underwent transvenous embolization for CSFVF. In 75 cases, detailed EP venography was available and categorized as: Type I (55%), homogeneous EP, Type II (34.5%), septated channels, and Type III (10.5%), complex, narrow pathways. Of the 75 cases with available EP venography, EP microcatheter navigation was performed in 65 cases: technical endpoints were extracted from these cases.

RESULTS: Overall, embolization was technically successful in all cases. EP navigation was performed in 65/75 cases (87%), with a 91% success rate overall: highest in Type I (97.5%)-Type II (90%), and lowest in Type III (50%). Type III EPs were associated with longer fluoroscopy times per level (510 vs 60-70 s, p=0.0008) and a higher rate of EP perforation (66% vs 10% Type I and 0% Type II; p<0.001). EP navigation time per segment decreased over time, from 130 s (first year) to 60 s (after 24 months), reflecting a learning curve.

CONCLUSIONS: The proposed EP classification correlates with procedural complexity and outcomes. It may aid in preprocedural planning and improve the safety and efficiency of transvenous CSFVF embolization.

PMID: 41093656  
DOI: 10.1136/jnis-2025-023993

AUTHORS: Ajay A Madhavan, Michelle L Kodet, Timothy J Amrhein, William P Dillon, Maggie Waung, Matthew Amans, Ian T Mark, Jeremy K Cutsforth-Gregory, Marcel M Maya, Wouter I Schievink

CITATION: AJNR Am J Neuroradiol. Published online October 10, 2025. doi:10.3174/ajnr.A9039

ABSTRACT: CSF-venous fistulas are a common cause of spontaneous intracranial hypotension. Although these fistulas are increasingly recognized and diagnosed, their risk factors and pathogenesis remain incompletely understood. Previous studies have elucidated many nonheritable risk factors associated with CSF-venous fistulas, including elevated body mass index, presence of spinal degenerative changes, and advanced age. Furthermore, these fistulas are associated with the presence of spinal meningeal diverticula, although many asymptomatic patients also possess these diverticula. There are likely additional predisposing factors for this disease that are yet to be discovered. The existence of CSF-venous fistulas among closely related relatives has not been previously studied, even though such cases may imply a heritable basis for this disease. In this clinical report, we performed a retrospective, multi-center case series describing four pairs of first-degree relatives (eight patients) who developed CSF-venous fistulas. We evaluated the clinical and imaging features of these patients, finding that the majority had an elevated body mass index and spinal meningeal diverticula. No patients had evidence of a connective tissue disorder. Overall, our study supports previous literature regarding nonheritable risk factors for CSF-venous fistulas but also suggests the presence of undiscovered genetic predispositions.

PMID: 41073138  
DOI: 10.3174/ajnr.A9039

AUTHORS: Soren Christensen, Peter G Kranz, Michael D Malinzak, Linda Gray, Jay Willhite, Daphne Zhu, Timothy J Amrhein

CITATION: Neuroradiol. Published online October 10, 2025. doi:10.3174/ajnr.A9038

ABSTRACT: A subset of postdural puncture headaches (PDPH) persist despite conventional epidural blood patches, leading to chronic symptoms and substantial disability. Dural punctures may involve not only the dorsal dural surface, which is covered by a standard interlaminar epidural blood patch (EBP), but also in some instances the ventral dural surface, which may not be covered by standard EBPs. This report describes the CT fluoroscopy-guided circumferential EBP, a technique that achieves 360° coverage of patching material around the thecal sac using combined ventral transforaminal and dorsal interlaminar injections. The procedural details for this technique are described, and the technical success and clinical results are reported for six patients with PDPH, four of whom had failed prior dorsal-only EBPs. Intraprocedural imaging confirmed complete circumferential patch coverage in all cases, and all six patients reported substantial or complete symptomatic resolution. These results establish the feasibility of CT fluoroscopy-guided circumferential EBP for PDPH.

PMID: 41073140 
DOI: 10.3174/ajnr.A9038

AUTHORS: Niklas Lützen, Horst Urbach, Florian Volz, Amir El Rahal, Katharina Wolf, Laura Krismer, Jürgen Beck, Charlotte Zander

CITATION: AJNR Am J Neuroradiol. Published online October 10, 2025. doi:10.3174/ajnr.A9040

BACKGROUND AND PURPOSE: Type 2 leaks occur in up to 20% of spontaneous intracranial hypotension (SIH) due to a spinal lateral dural tear, typically accompanied by arachnoid hernia. Their CSF-outflow dynamics are unclear, but could have implications on performing myelography for best possible detection. This cross-sectional study analyzed temporal characteristics of type 2 leaks using digital subtraction myelography (DSM)

MATERIALS AND METHODS: Between February 2020 and April 2025, 63 consecutive patients with type 2 leaks were retrospectively identified. Patients undergoing sufficient decubitus DSM (comprising additional fluoroscopy and X-ray images) were included. We assessed the time for the contrast agent to first appear in the epidural space after reaching the level of the leak intrathecally at 1-2 frames-per-second (fps), and categorized them as fast (0-9 sec), medium (10-90 sec), and slow (>90 sec) leaks. Furthermore, effects of intrathecal pressurization, arachnoid hernia size, opening pressure and symptom-duration on CSF-outflow were studied.

RESULTS: Forty-five patients (36 women) were included. Mean age was 39.0 years (SD ± 11.4 years), mean BMI 23.2 (SD ± 3.9) and median Bern score 6 (IQR 5). Type 2 leaks most commonly occurred at the T10/11 level (12/45; 26.7%) ranging between T7/8 -L1/2. During DSM, contrast appeared in the epidural space within 0-9 sec in 3/45 (6.7%), 10-90 sec in 24/45 (53.3%) and >90 sec in 5/45 (11,1%) of cases (range: 4 to 473 sec). If DSM (or fluoroscopy/X-ray) missed the leak, subsequent cone-beam or CT myelography detected it (13/45; 28.9%); total slow leaks were 18/45 (40%). All patients undergoing surgery (40/45) had the leak confirmed intraoperatively. In a subgroup of patients undergoing pressurization during DSM (12/45), there were significantly more leaks detected within 90s (p=0.02), while arachnoid hernia size, opening pressure and symptom duration did not affect CSF-outflow significantly.

CONCLUSIONS: Type 2 leaks show a wide range of CSF-outflow characteristics, with most being medium and slow. For DSM, we propose using a 90-second run with intrathecal pressurization and cone-beam CT standby for effective leak detection, whereas less than 1 fps (e.g., 0.5 fps) seems feasible to minimize radiation. Alternatively, dynamic CT myelography can be considered -although timing of CT scans has yet to be evaluated.

PMID: 41073137 
DOI: 10.3174/ajnr.A9040

AUTHORS: Mark D Mamlouk, James F R Latoff, Adriana Gutierrez, Mark F Sedrak

CITATION: AJNR Am J Neuroradiol. Published online October 10, 2025. doi:10.3174/ajnr.A9042

BACKGROUND AND PURPOSE: CSF-venous fistulas (CVFs) are an increasingly recognized cause of spontaneous intracranial hypotension and require invasive myelography for localization. Whether spine MRI can noninvasively predict CVF origin remains unclear. The purpose of our study was to determine if spine MRI features, particularly the size and location of spinal meningeal diverticula, are predictive of the CVF location identified on myelography.

MATERIALS AND METHODS: Retrospective review of 100 patients with a CVF confirmed on decubitus CT myelography who underwent preprocedural spine MRI. The primary outcome was whether the CVF arose at or adjacent to the largest diverticulum. Secondary outcomes included distribution patterns of largest adjacent-level diverticula and their spatial relationship to the CVF (cranial, caudal, ipsilateral, contralateral). Chi-square tests, one-sided binomial tests, and t-tests were used to assess statistical significance.

RESULTS: CVFs originated at or adjacent to the largest diverticulum in 77% of patients, significantly more than expected by chance (P < .001). 71.7% of CVFs were within one level of the adjacent largest diverticulum on spine MRI. Among adjacent-level cases of the largest diverticula, there was a significant directional preference for the adjacent largest diverticulum to occur caudal to the CVF compared to a uniform distribution (P = .001). There were three specific diverticular patterns that were statistically significant: caudal and ipsilateral 1 level below the CVF (P < .001), contralateral same level (P < .001), and caudal and contralateral 1 level (P= 0.002). There was no significant correlation between the laterality of the largest diverticulum size nor the laterality of the majority of the diverticula compared to the laterality of the CVF.

CONCLUSIONS: Spinal CVFs most commonly arise at or adjacent to the largest meningeal diverticulum. The adjacent largest diverticulum was commonly within one level to the CVF and most commonly caudal one level to the CVF or at the same level contralateral side to the CVF. These MRI-based predictors may help guide myelography.

PMID: 41073141  
DOI: 10.3174/ajnr.A9042

AUTHORS: William Chapman, Kevin Tay, Roshan Dhanapalaratnam, Harry Leung, Alessandro S Zagami, William Huynh

CITATION: Acta Neurol Belg. Published online October 9, 2025. doi:10.1007/s13760-025-02911-y

🔓Open access! Full study available here.

BACKGROUND: Patients with connective tissue disorders such as Marfan syndrome confer an increased risk of spontaneous intracranial hypotension as they are predisposed to structural weaknesses causing dura ectasia. Rebound intracranial hypertension can develop as an acute complication of epidural blood patches used to treat CSF leaks but has not been previously described in patients with Marfan.

CASE STUDY: A 17-year-old male patient with Marfan Syndrome who presented with postural headaches was initially diagnosed with intracranial hypotension and successfully treated with an epidural blood patch targeting the spinal CSF leak identified on myelogram with complete clinical and radiological resolution. Approximately 11 months after this, he re-presented with a reversal of his postural headaches, new papilledema, and an opening pressure of 35cmH2O with features of raised intracranial pressure on a brain MRI. Rebound intracranial hypertension with this latency is infrequently reported particularly in a patient with Marfan syndrome.

CONCLUSION: This case highlights the importance in recognising this potential delayed complication of CSF leak treatment, and distinguishing between rebound intracranial hypertension and recurrence of intracranial hypotension as there are differing diagnostic and management implications.

PMID: 41065992  
DOI: 10.1007/s13760-025-02911-y

AUTHORS: Saujanya Rajbhandari, Thomas Petutschnigg, Levin Häni, Danial Nasiri, Johannes Goldberg, Christoph Schankin, Adrian Scutelnic, Philipe Breiding, Lorenz Grunder, David Brustman, Andreas Raabe, Jan Gralla, Sara Pilgram-Pastor, Johannes Kaesmacher, Katharina Wolf, Jürgen Beck, Ralph T Schär, Eike Piechowiak, Tomas Dobrocky

CITATION: AJNR Am J Neuroradiol. Published online October 9, 2025. doi:10.3174/ajnr.A9032

BACKGROUND AND PURPOSE: Localizing a cerebrospinal fluid (CSF) leak in spontaneous intracranial hypotension (SIH) patients is of utmost importance when pursuing a targeted therapy. The study aimed to evaluate the accuracy of dynamic myelography techniques in localizing spinal CSF leaks and report the number of examinations required, stratified by leak type and spinal level.

MATERIALS AND METHODS: Consecutive SIH patients with a spinal longitudinal extradural CSF collection (SLEC) investigated at our department from January 2013 to February 2025 were screened. All included patients underwent a dynamic myelography work-up to localize the level of spinal CSF leak using conventional dynamic myelography (CDM), and/or dynamic computed tomography myelography (DCTM).

RESULTS: In total, 198 SLEC positive SIH patients (mean age: 50 ± 12 years; 67% female, 133/198) were included. In total, 147 patients had a ventral (74%), 49 patients had lateral (25%), and two patients had a primary dorsal (1%) leak. The spinal CSF leak was localized with the first, second, third or fourth dynamic myelography in 97 (49%), 70 (35%), 16 (8%), 11 patients (6%), respectively. The median number of myelography exams (CDM + DCTM) per patient to localize a CSF leak was 2 (IQR 1-2; range 1-8); 1 (IQR 1-2; range 1-5) for ventral, 2 (IQR 1-2; range 1-6) for lateral and 6 (IQR 5-7; range 4-8) for dorsal leaks. In total, 160 patients (81%) were referred for microsurgical closure. The dural leak was identified intraoperatively on the indicated vertebral level in 153 patients (96%), in 2 patients (1.3%) spontaneous sealing occurred, in 5 patients (3%) wrong-level surgery occurred.

CONCLUSIONS: Dynamic myelography exams accurately and reliably localize spinal CSF leaks in SIH patients with SLEC. In about half of the patients, the level of the leak can be localized with the first CDM. In case of a repeat dynamic myelography, the technique and patient positioning can be adopted according to the results of the previous exam. Primary dorsal leaks are rare, but due to the low level of suspicion, pose a diagnostic challenge.

PMID: 41067914 
DOI: 10.3174/ajnr.A9032

AUTHORS: Maria P Puello, Premal Trivedi, Kathryn Kerrigan, Andrea Walters, Debayan Bhaumik, Peter Lennarson, Andrew L Callen

CITATION: AJNR Am J Neuroradiol. Published online October 8, 2025. doi:10.3174/ajnr.A9036

BACKGROUND AND PURPOSE: Patients with spontaneous intracranial hypotension (SIH) often face substantial delays in diagnosis and treatment. Barriers to accessing specialized care for SIH remain poorly understood, particularly with regard to potential demographic and/or socioeconomic disparities. The purpose of this study is to evaluate whether patients seen in a specialized CSF leak clinic differ demographically or socioeconomically from those presenting to the emergency department (ED) with headache who receive neuroimaging.

MATERIALS AND METHODS: We retrospectively compared all patients evaluated in the University of Colorado CSF Leak Program in March 2025 to patients presenting to the ED at our institution during the same month with a primary complaint of headache who underwent neuroimaging. Demographic and socioeconomic variables were extracted from the electronic medical record and compared between groups using the chi-square test, t-tests, or the Mann-Whitney U test, as appropriate.

RESULTS: A total of 95 patients from the CSF leak clinic and 130 patients from the ED headache clinic were included in this study. Patients seen in the CSF leak clinic were significantly more likely to be female (76.8% vs. 57.7%, χ2=8.9, p=0.003), white (89.5% vs. 47.7%, χ2=45.5, p <0.001), have private insurance (72.6% vs. 41.5%, χ2=27.91, p <0.001), and report English as their primary language (96.8% vs. 75.4%, χ2=21.3, p <0.001). The median driving distance to the hospital was substantially longer in the CSF clinic cohort (23 miles, IQR 12-70 vs. 7 miles, IQR 6-12; Mann-Whitney U = 9562, p <0.001). ZIP code-based household income did not differ significantly between groups ($98,000 vs. $91,000; t = 1.20, p = 0.11).

CONCLUSIONS: Patients accessing specialized care for SIH at a tertiary referral center are more likely to be white, English-speaking, and privately insured compared to patients presenting to the ED with headache, despite coming from farther geographic distances. These findings suggest significant disparities in access to specialty care for SIH, highlighting the need for targeted outreach, streamlined referral pathways, and broader diagnostic awareness in general practice and emergency settings.

PMID: 41062183 
DOI: 10.3174/ajnr.A9036

AUTHORS: Atakan Orscelik, Jeremy K Cutsforth-Gregory, Ajay Madhavan, Yigit Can Senol, Hassan Kobeissi, Gokce Belge Bilgin, Cem Bilgin, David F Kallmes, Waleed Brinjikji 

CITATION: Neurosurg Clin N Am. 2025;36(4):613-622. doi:10.1016/j.nec.2025.04.014

ABSTRACT: Cerebrospinal fluid-venous fistula (CVF) is an important cause of spontaneous intracranial hypotension (SIH), a condition characterized by low cerebrospinal fluid (CSF) volume and orthostatic headaches. The pathogenesis of CVF is thought to be direct connection of the spinal dura to one or more veins in the epidural space, allowing unregulated flow of CSF into the venous system. Herein, we provide a comprehensive review of the endovascular management of CVF in patients with SIH. We also focus on the various techniques and devices used in endovascular treatment, as well as the pathogenesis, diagnosis, and alternative treatment options of CVF.

PMID: 41167830 
DOI: 10.1016/j.nec.2025.04.014

AUTHORS: Jessica L Houk, Peter G Kranz, Timothy J Amrhein

CITATION: Neurosurg Clin N Am. 2025;36(4):601-611. doi:10.1016/j.nec.2025.04.004

ABSTRACT: Spontaneous intracranial hypotension (SIH) is a treatable cause of orthostatic headaches secondary to pathologic loss of cerebrospinal fluid (CSF) from the subarachnoid space. SIH has several known pathologic causes including dural tears from disc osteophytes, leaks emanating from nerve root sleeve diverticula, and CSF-venous fistulas (CVFs). Depending on the type of leak, surgical repair or endovascular techniques may be options for definite treatment. However, epidural blood patching (EBP) remains first-line therapy for many patients due to its long track record, broad availability, and relatively lower risk profile. This review focuses on indications and techniques for the percutaneous treatment of SIH and provides an overview of post-procedural management of these patients.

PMID: 41167829 
DOI: 10.1016/j.nec.2025.04.004

AUTHORS: Javier Galvan, Marcel Maya, Ravi S Prasad, Vikram S Wadhwa, Wouter Schievink

CITATION: Neurosurg Clin N Am. 2025;36(4):589-600. doi:10.1016/j.nec.2025.05.001

ABSTRACT: Cerebrospinal fluid (CSF) leak can cause spontaneous intracranial hypotension (SIH) which can lead to neurologic symptoms, such as orthostatic headache. Over time, imaging techniques for detecting and localizing CSF leaks have improved. These techniques include computed tomography (CT) myelography, dynamic CT myelography, cone-beam CT, MRI, MR myelography, and digital subtraction myelography (DSM). DSM provides the highest sensitivity for identifying leak sites and has comparable radiation exposure to CT myelography. The introduction of the lateral decubitus DSM has proven invaluable in localizing leaks when other imaging tests have been inconclusive.

PMID: 41167828  
DOI: 10.1016/j.nec.2025.05.001

AUTHORS: Mario Zanaty, Clayton Lawrence Rosinski, Mohamed Elshikh, Jay Kinariwala, Satoshi Yamaguchi, Kathleen Dlouhy, Edgar Samaniego, Pascal Jabbour, Minako Hayakawa, Santiago Ortega-Gutierrez 

CITATION: Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences, 15910199251376452. 30 Sep. 2025, doi:10.1177/15910199251376452

ABSTRACT: Spontaneous intracranial hypotension (SIH) is a severe condition caused by cerebrospinal fluid (CSF) leaks, leading to headaches and neurological impairments. Traditional epidural blood patch treatment is often ineffective, especially in refractory cases without a source leak identified. This study introduces and evaluates the Catheter-Assisted Sealing Technique (CAST), a novel neurointerventional approach for refractory SIH. CAST involves targeted or diffuse delivery of fibrin glue into the epidural space to repair CSF leaks.MethodsA retrospective case series of ten patients with refractory SIH underwent CAST using a fluoroscopy-guided epidural catheter approach. Clinical symptom resolution and follow-up MRI findings were assessed.ResultsNine of 10 patients achieved complete headache resolution and associated symptom relief. One patient experienced significant improvement without complete relief. Follow-up MRI showed resolution of pachymeningeal enhancement in all patients. One patient required repeat procedures for recurrent symptoms. No neurological injury or spinal cord compression occurred, with the only complication being transient femoral nerve palsy due to positioning that resolved within four months.ConclusionCAST is a promising, minimally invasive alternative for refractory SIH. It enables targeted or diffuse fibrin sealant application, providing a seemingly effective leak closure even in cases of occult or multifocal leaks. Early results show high success and safety rates, but larger cohorts and extended follow-up are needed to validate it as a standard treatment.

PMID: 41026952 
DOI: 10.1177/15910199251376452

AUTHORS: Charlotte Zander, Christian Fung, Amir El Rahal, Florian Volz, Katharina Wolf, Alexander Rau, Hansjörg Mast, Jürgen Beck, Horst Urbach, Niklas Lützen

CITATION: Headache, 10.1111/head.15057. 23 Sep. 2025, doi:10.1111/head.15057

🔓Open access! Full study available here.

OBJECTIVE: This study evaluated cranial magnetic resonance imaging (MRI) signs in patients with post-dural puncture headache (PDPH) using an established assessment score developed for spontaneous intracranial hypotension (Bern score). We hypothesize that patients with chronic PDPH do not have typical imaging features of intracranial hypotension.

BACKGROUND: PDPH is a well-known complication following an intentional or unintentional lumbar dural puncture with positional headache, neck stiffness, and hearing disturbances usually resolving within 14 days. However, the chronic course of PDPH is poorly represented in the third version of the International Classification of Headache Disorders (ICHD-3). Moreover, data on the role of cranial MRI in this cohort are lacking, but could facilitate care and management of chronic PDPH.

METHODS: In this post hoc retrospective case series based on a chart review, we identified 86 consecutive patients from a tertiary medical care center in Freiburg, Germany between 01/2018 and 10/2024 with chronic PDPH, defined as persisting symptoms for >14 days post puncture and/or persisting after one or more epidural blood patches (EBP). Inclusion criteria were history of lumbar puncture (LP) or unintended dural puncture (UDP) and contrast enhanced cranial MRI for assessment of Bern score in all patients. Presence of epidural lumbar fluid was evaluated using heavily T2-weighted MRI or computed tomography (CT) myelography, whenever available (83/86 patients). Data were reviewed independently and blinded by two radiologists.

RESULTS: Eighty-six patients with chronic PDPH (66 females; mean age of 38.8 ± 11.2 SD years) were included with LP as primary cause in 72% (n=62) and UDP while peridural (synonymous epidural) anesthesia (PDA) in 28% (n = 24). Median symptom duration was 220.0 (interquartile range [IQR] 94.0-474.0) days. Overall median Bern score was 2.0 (IQR 1.0-3.0) with no significant differences between LP versus PDA (p = 0.379). Local epidural fluid was present in 9/83 (11%) cases with adequate imaging and accompanied by higher median Bern scores (5.0 vs. 2.0; p = 0.026). Prior EBP was linked to lower median Bern scores (1.0 vs. 3.5; p < 0.001).

CONCLUSION: Patients with chronic PDPH predominantly present a low Bern score and rarely exhibit spinal epidural fluid. If present, spinal epidural fluid is accompanied by higher Bern score. Our findings highlight the unreliability of current MRI diagnostics to detect patients with chronic PDPH, which must not lead to a mitigation of the diagnosis or a refusal of treatment. Further research on MRI markers is needed here.

PMID: 40988109  
DOI: 10.1111/head.15057

AUTHORS: Christian Fung, Luisa Mona Kraus, Amir El Rahal, Levin Haeni, Florian Volz, Katharina Wolf, Mukesch Johannes Shah, Horst Urbach, Niklas Lützen, Jürgen Beck 

CITATION: Neurology vol. 105,6 (2025): e213998. doi:10.1212/WNL.0000000000213998

BACKGROUND AND OBJECTIVES: Chronic orthostatic headache after dural puncture is a serious condition lacking defined diagnostic criteria and pathophysiologic understanding. Prevailing opinion suggests CSF outflow through an unsealed dural hole after a lumbar puncture. We aimed to systematically search for a leak with MRI and perform dynamic CSF infusion testing in patients with chronic orthostatic headache after a lumbar puncture.

METHODS: In a retrospective, single-center cohort study at the Medical Center-University Hospital Freiburg, patients with chronic postdural puncture headache (cPDPH), defined by a history of dural puncture and new orthostatic headache either persisting >14 days after puncture and/or persisting after 1 or more epidural blood patches (EBPs), were included between April 2018 and July 2022. We excluded patients with proven spontaneous CSF leakage and those with previous interventions other than EBPs. Our workup included clinical data such as demographics, symptoms, prior treatment, and imaging data. We analyzed opening pressure and CSF dynamics by lumbar infusion test (LIT) including resistance to CSF outflow (RCSF), pressure at baseline and plateau, pulse amplitude at baseline and plateau, elastance, and pressure-volume index (PVI).

RESULTS: We included 21 consecutive patients with cPDPH in our final cohort. Complete data sets were available in 21 patients, of whom 19 were female and 2 were male. The median age was 39 years (interquartile range [IQR] 30-49 years). Spinal imaging showed pathologic extrathecal fluid in 2 patients (10%). After lumbar puncture, the median opening pressure was 12 cmH2O (IQR 9-17). LIT yielded a median RCSF of 10.77 mm Hg/(mL/min) (IQR 6.79-13.78), a median lumbar pressure baseline of 9.84 mm Hg (IQR 7.24-14.05), and a median PVI of 13.47 mL (IQR 9.62-18.47). There was no correlation between LIT parameters and symptom duration.

DISCUSSION: Our results do not support the hypothesis that all patients with cPDPH have a leaking dural defect or are in a state of CSF depletion. We conclude that symptoms may not be related to CSF dynamics as measured by opening pressure or with LIT and that further investigation into the pathomechanism of persisting orthostatic symptoms is warranted.

PMID: 40857657 
DOI: 10.1212/WNL.0000000000213998

AUTHORS: Bala McRae-Posani, Sara Strauss, Matthew S Robbins, Gayle Salama

CITATION: Clinical neurology and neurosurgery, vol. 258 109169. 22 Sep. 2025, doi:10.1016/j.clineuro.2025.109169

OBJECTIVE: To report CSF pressure (Pcsf) and its correlations in patients with SIH due to CSF-venous fistula (CVF).

METHODS: Following IRB approval, consecutive SIH patients undergoing myelography between 2021 and 2025 at a single center were retrospectively analyzed. Pcsf was defined as opening pressure (OP) during myelography, with patient in decubitus positioning with mild hip elevation. Low OP was defined as < 6 cm H2O; elevated OP as > 20 cm H2O.

RESULTS: Of the 86 SIH patients analyzed, 35 (41 %) had a CVF [average age 59 ± 13; 12/35 (34 %) male; 23/35 (66 %) female]. Of the 35, OP was reported for 32 patients. The mean ± SD OP was 13.97 ± 3.91 cm H2O (range: 6-25 cm H2O). None (0 %) of the patients had low OP. 29/32 (91 %) had OP in normal range, 3/32 (9 %) had elevated OP. Pcsf was positively correlated with BMI (p = 0.045); but not correlated with age, sex, prior epidural blood patching, symptom duration, or mean arterial pressure. High variability in Pcsf values was not fully accounted for by predictors included in our model (pseudo-R2 = 0.188).

CONCLUSIONS: An absence of low Pcsf should not be used to rule out SIH, as all our patients with SIH due to CVF had normal or elevated Pcsf. Such Pcsf readings in patients with active CSF leaks suggest that the development of CVF and post-treatment rebound headaches may be due to pre-existing intracranial hypertension. While BMI is positively correlated with Pcsf, limited explanatory power of our model suggests influence of other factors.

PMID: 40992352
DOI: 10.1016/j.clineuro.2025.109169

AUTHORS: Parnian Habibi, Jared T Verdoorn, Ajay A Madhavan, John C Benson, Waleed Brinjikji, Ben A Johnson-Tesch, Chelsea J Dahl, Jeremy Cutsforth-Gregory, Ian T Mark

CITATION: AJNR. American journal of neuroradiology, ajnr.A9012. 18 Sep. 2025, doi:10.3174/ajnr.A9012

BACKGROUND AND PURPOSE: Spontaneous intracranial hypotension (SIH) is a disabling condition that is frequently underdiagnosed due to diagnostic challenges. Delays in diagnosis can be attributed to underrecognized MRI findings or lack of clinical suspicion, given the wide range of symptoms. This study aims to explore the diagnostic burden of SIH by examining the number of imaging exams and clinician visits prior to diagnosis.

MATERIALS AND METHODS: This retrospective single-institution study included 71 patients with spinal CSF leaks who had a confirmed diagnosis of CSF-venous fistula (CVF) on digital subtraction myelography (DSM). We reviewed each patient’s clinical history, including the number of providers in different specialties and institutions, as well as the number and type of imaging studies performed prior to the positive DSM at our center. Brain MR images were scored using the Bern criteria, and clinical history along with imaging data were compared across Bern groups (low, intermediate, high probability).

RESULTS: The mean patient age was 57.6 years with the majority being female (65%). The mean duration of symptoms was 3.8 years, and 14.1% of patients experienced symptoms for ≥10 years prior to the positive DSM. The mean number of specialists seen per patient was 2.6 (SD = 2.7; range, 0-13), and 28% of patients consulted 4 or more specialists prior to the positive DSM. On average, each patient underwent 6 imaging studies (SD: 3.8; range: 2-22) before the DSM, including 5.3 MRIs (SD: 3.7; range: 2-22), and 2.5 brain MRIs (SD: 2.1; range: 1-11). 40.8% of patients underwent ≥ 7 total imaging studies, and 53.5% had ≥ 3 Brain MRIs prior to diagnosis. Although no significant differences were found in the mean number of specialists or imaging exams between Bern score groups, a trend of increasing diagnostic burden was observed from the high to low Bern score groups.

CONCLUSIONS: Patients with spinal CSF leaks often undergo an extensive number of imaging and specialty consultations, contributing to delays in diagnosis and appropriate treatment. This study highlights the need to increase awareness among healthcare providers regarding the typical symptoms and imaging features of spinal CSF leaks.

PMID: 40968013  
DOI: 10.3174/ajnr.A9012

AUTHORS: Anahita Malvea, Emily Chung, Mehran Nasralla, Eef J Hendriks, Richard I Farb 

CITATION: Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences, 15910199251375541. 16 Sep. 2025, doi:10.1177/15910199251375541

🔓Open access! Full study available here.

ABSTRACT: Dynamic myelography, performed as digital subtraction myelography or dynamic computed tomography myelography, is crucial in diagnosing intracranial hypotension resulting from a cerebrospinal fluid-venous fistula (CVF). The quality of the myelogram is paramount for accurate diagnosis. Using a phantom, the impact of needle type (Quincke vs. Whitacre), caliber, side-hole position, and rate of injection on the quality of the myelogram was determined. The ideal decubitus myelogram would provide a large volume of a hyperdense contrast within the lateral dependent aspect of the thecal sac, optimally flooding the mouths of the neural foramina and root sleeves where the vast majority of CVFs originate. The results of this study suggest it is exclusively the rate of injection that most predictably dictates the quality of the myelogram in this regard. Specifically, a slow injection rate, on the order of 0.1 mL/s, should be opted for to decrease turbulence, optimize myelogram quality, and thus improve CVF detection in clinical practice.

PMID: 40956898
PMCID: PMC12440920
DOI: 10.1177/15910199251375541 

AUTHORS: Andrew V Mecum, B K Kleinschmidt-DeMasters, Debayan Bhaumik, Samantha L Pisani Petrucci, Peter J Lennarson, Andrew L Callen

CITATION: AJNR Am J Neuroradiol. Published online September 11, 2025. doi:10.3174/ajnr.A8782

ABSTRACT: CSF-venous fistulas (CVFs) are recognized as the most common cause of spontaneous intracranial hypotension, however, exactly how and why CVFs form remains unclear. To better elucidate CVF pathophysiology, histopathologic analysis was performed in 5 patients with CVFs who underwent operative ligation and removal of the implicated nerve root. There were no archetypal findings seen uniformly in all 5 cases, and no definitive CSF-venous connections were visualized. However, all cases manifested variable vascular abnormalities. These included dystrophic mineralization in venous walls, focal venous wall thinning, thrombosis, and hemosiderin deposition. Collectively, these findings suggest venous alterations are associated with CVFs, though causality cannot be determined.

PMID: 40210461
DOI: 10.3174/ajnr.A8782 

AUTHORS: David Rowland, Dwij Mehta, Ayman Qureshi, Indran Davagnanam, Ahmed K Toma, Parag Sayal, Manjit Matharu 

CITATION: Practical neurology, pn-2025-004683. 2 Sep. 2025, doi:10.1136/pn-2025-004683

ABSTRACT: A 49-year-old woman developed symptoms of syringomyelia 3 years after having presented with spontaneous intracranial hypotension (SIH). She had previously undergone two unsuccessful non-targeted epidural blood patches. The MR scan showed features of cervicothoracic syringomyelia and ongoing intracranial features of SIH. Following two further ineffective non-targeted epidural blood patches, a cerebrospinal fluid venous fistula was identified on myelography, which was surgically disconnected. At subsequent follow-up, she showed marked and progressive clinical and radiological improvement. This case shows that offering curative treatment for the underlying cause of SIH is an effective-and the preferred-way of managing SIH-associated syrinx.

PMID: 40897546 
DOI: 10.1136/pn-2025-004683

AUTHORS: Samantha L Pisani Petrucci, Debayan Bhaumik, Andrew L Callen

CITATION: AJNR Am J Neuroradiol. 2025;46(9):1952. Published 2025 Sep 2. doi:10.3174/ajnr.A8903

ABSTRACT: Successful localization of CSF leaks on dynamic CT myelography requires a refined technical approach. In this video article, methods are presented to select and optimize patient position, as well as highlight potential pitfalls and strategies to augment utility in the setting of a difficult examination. Careful understanding and refinement of patient positioning in dynamic CT myelography ensures the performance of high-fidelity examinations with maximal diagnostic yield, decreasing the need for repeat studies and lumbar punctures.

PMID: 40675809
PMCID: PMC12453484 (available on 2026-09-01)
DOI: 10.3174/ajnr.A8903

AUTHORS: Charlotte E Michaelcheck, Waleed Brinjikji, Ajay A Madhavan, John C Benson, Jared T Verdoorn, Ben Johnson-Tesch, Jeremy Cutsforth-Gregory, Ian T Mark

CITATION: AJNR Am J Neuroradiol. 2025;46(9):1939-1942. Published 2025 Sep 2. doi:10.3174/ajnr.A8746

BACKGROUND AND PURPOSE: CSF-venous fistulas (CVF) are abnormal connections between the subarachnoid space and a paraspinal vein. Transvenous Onyx embolization is a recently adopted treatment method for CVF closure, however no studies have specifically evaluated for Onyx migration into the CSF. The purpose of our study was to evaluate patients who underwent transvenous CVF embolization for Onyx migration into the CSF.

MATERIALS AND METHODS: We evaluated 100 patients who underwent transvenous CVF embolization for post-treatment CT of the spine. Images were reviewed for Onyx migration into the CSF at the level of the embolization as well as distally in the lumbar spine. Basic demographic information including age and sex were recorded.

RESULTS: The mean age was 59.2 years (+/-10.9, 28-88). 68 were female. 48 patients had post-embolization imaging of the treated level, and none had Onyx migration into the CSF at the level of the CVF. 34 patients had imaging of the lumbar spine, and none had Onyx migration distally in the lumbar spine.

CONCLUSIONS: Our study did not find any cases of unintended Onyx migration into the subarachnoid space in patients who underwent transvenous CVF embolization. This speaks to the safety profile of transvenous CVF embolization and suggests possible one-way physiology of CVF that allows for egress from the CSF to the veins only.

PMID: 40473425
DOI: 10.3174/ajnr.A8746

AUTHORS: Daniel Montes, Samantha L Pisani Petrucci, Debayan Bhaumik, Nadya Andonov, Peter Lennarson, Andrew L Callen

CITATION: AJNR Am J Neuroradiol. 2025;46(9):1931-1938. Published 2025 Sep 2. doi:10.3174/ajnr.A8720

BACKGROUND AND PURPOSE: Epidural patching with autologous blood and/or fibrin sealant is a common treatment for spinal CSF leaks, yet the factors influencing patch distribution remain poorly understood. This study aimed to analyze the craniocaudal (CC) and ventral epidural (VE) extent of epidural patch material and investigate the impact of variables such as patch volume (PV), composition, spinal level of injection, and patient habitus on distribution patterns.

MATERIALS AND METHODS: This retrospective, cross-sectional cohort study included patients who underwent CT-guided epidural patching from January to September 2024. Inclusion criteria were age ≥18 years, dorsal interlaminar (DI) or transforaminal (TFO) epidural patching by using blood, fibrin, or both, and immediate postpatch imaging capturing the entire patch extent. Patch distribution was assessed for CC and VE spread. Statistical analyses included linear and logistic regression models, with multivariate analyses adjusting for confounders.

RESULTS: Of 152 patients patched during the study period, 33 met inclusion criteria (mean age 45.4 years; 84.1% women) with 44 spinal levels patched: cervical (6.8%), thoracic (68.2%), and lumbar (25%). Mean PV per needle was 7.2 mL, with a mean CC spread of 4.6 spinal levels. There was a positive relationship between PV and CC spread across all spinal levels (β = 0.29, P = .001). Patches in the cervical region demonstrated the highest CC spread efficiency (0.77 levels per milliliter) compared with thoracic (0.56 levels per milliliter) and lumbar patches (0.47 levels per milliliter; P < .01). DI injections achieved greater CC spread but less VE dispersion than TFO injections (5.0 versus 3.2 levels; P = .02; 58.8% versus 70.0%, P = .52). VE spread occurred in 61.4% of cases and followed a nonlinear pattern along the spine, with an inflection point at T3.

CONCLUSIONS: The distribution of epidural patch material is influenced by spinal level, PV, composition, and injection approach. Cervical patches provide the greatest spread efficiency relative to volume, while DI approaches enhance CC spread but reduce ventral dispersion.

PMID: 40000121
PMCID: PMC12453460 (available on 2026-09-01) 
DOI: 10.3174/ajnr.A8720

AUTHORS: Ajay A Madhavan, Zhongxing Zhou, Paul J Farnsworth, Jamison Thorne, Timothy J Amrhein, Peter G Kranz, Waleed Brinjikji, Jeremy K Cutsforth-Gregory, Michelle L Kodet, Nikkole M Weber, Grace Thompson, Felix E Diehn, Lifeng Yu 

CITATION:AJNR. American journal of neuroradiology vol. 46,8 1731-1735. 1 Aug. 2025, doi:10.3174/ajnr.A8695

BACKGROUND AND PURPOSE: Photon-counting detector CT myelography (PCD-CTM) is a recently described technique used for detecting spinal CSF leaks, including CSF-venous fistulas. Various image reconstruction techniques, including smoother-versus-sharper kernels and virtual monoenergetic images, are available with photon-counting CT. Moreover, denoising algorithms have shown promise in improving sharp kernel images. No prior studies have compared image quality of these different reconstructions on photon-counting CT myelography. Here, we sought to compare several image reconstructions using various parameters important for the detection of CSF-venous fistulas.

MATERIALS AND METHODS: We performed a retrospective review of all consecutive decubitus PCD-CTM between February 1, 2022, and August 1, 2024, at 1 institution. We included patients whose studies had the following reconstructions: Br48-40 keV virtual monoenergetic reconstruction, Br56 low-energy threshold (T3D), Qr89-T3D denoised with quantum iterative reconstruction, and Qr89-T3D denoised with a convolutional neural network algorithm. We excluded patients who had extradural CSF on preprocedural imaging or a technically unsatisfactory myelogram-. All 4 reconstructions were independently reviewed by 2 neuroradiologists. Each reviewer rated spatial resolution, noise, the presence of artifacts, image quality, and diagnostic confidence (whether positive or negative) on a 1-5 scale. These metrics were compared using the Friedman test. Additionally, noise and contrast were quantitatively assessed by a third reviewer and compared.

RESULTS: The Qr89 reconstructions demonstrated higher spatial resolution than their Br56 or Br48-40keV counterparts. Qr89 with convolutional neural network denoising had less noise, better image quality, and improved diagnostic confidence compared with Qr89 with quantum iterative reconstruction denoising. The Br48-40keV reconstruction had the highest contrast-to-noise ratio quantitatively.

CONCLUSIONS: In our study, the sharpest quantitative kernel (Qr89-T3D) with convolutional neural network denoising demonstrated the best performance regarding spatial resolution, noise level, image quality, and diagnostic confidence for detecting or excluding the presence of a CSF-venous fistula.

PMID: 39929540 
DOI: 10.3174/ajnr.A8695

AUTHORS: Niklas Lützen, Charlotte Zander, Jürgen Beck, Florian Volz, Katharina Wolf, Amir El Rahal, Horst Urbach

CITATION: AJNR. American journal of neuroradiology vol. 46,8 1736-1740. 1 Aug. 2025, doi:10.3174/ajnr.A8675

ABSTRACT: Type 2 CSF leaks are spinal lateral dural tears, causing spontaneous intracranial hypotension. They may be visualized with digital subtraction myelography, conebeam CT myelography, and energy-integrating detector or photon-counting CT myelography. A recently introduced ultra-high-resolution conebeam CT myelography has shown beneficial visualization of CSF-venous fistulas, another cause of spontaneous intracranial hypotension. However, the use of this technique has not yet been reported in imaging of type 2 leaks. In this technical report, we describe our first experiences and highlight the advantages of ultra-high-resolution conebeam CT for visualizing type 2 leaks in spontaneous intracranial hypotension.

PMID: 39880689
DOI: 10.3174/ajnr.A8675

AUTHORS: Adrian Scutelnic, Andreas Lüthi, Isabelle Dominique Stöckli, Lucie Justus, Bettina Bracher, Antonia Klein, Nedelina Slavova, Eric Morel, Franz Riederer, Tomas Dobrocky, Eike I Piechowiak, C Marvin Jesse, Christian T Ulrich, Jürgen Beck, Ralph T Schär, Christoph J Schankin

CITATION: European journal of neurology vol. 32,8 (2025): e70237. doi:10.1111/ene.70237

🔓Open access! Full study available here.

INTRODUCTION: Spontaneous intracranial hypotension (SIH) is an important cause of headache that might require invasive treatment. The aim of this study was to systematically investigate (1) clinical presentation, (2) factors associated with incomplete headache resolution, and (3) the long-term outcomes in patients with persistent headache after invasive treatment for SIH.

METHODS: This is an observational longitudinal study. We used a structured questionnaire to assess details on primary headache, SIH-headache, and headache after treatment. Persistent headache was defined as headache on more than 15 days per month lasting longer than 3 months.

RESULTS: Fifty-six patients invasively treated for SIH were included in the study. The mean age was 49 ± 12 years, and 60% were women. After sealing of the leak, 11/56 (20%) had persistent headache. Compared to subjects without persistent headache, patients with persistent headache had been treated after a longer delay from SIH symptom onset (362 days [IQR 138-714] vs. 111 [68-365]). In 2/11 (18%) patients, a second leak at another level and rebound intracranial hypertension were found, respectively. Medication overuse was reported by 3/11 (27%) patients. After a median follow-up of 5 years, headache subsided completely in 4/11 (36%) patients and improved in 4/11 (36%).

CONCLUSION: In our cohort, one fifth of patients suffered from persistent headache despite successful sealing of the CSF leak. Although the majority of patients showed improvement in the long run, important secondary headaches should be considered, namely medication overuse, rebound hypertension, and a persistent, reopened, de novo or second leak at another level.

PMID: 40781935  
PMCID: PMC12334888
DOI: 10.1111/ene.70237

AUTHORS: Ajay A. Madhavan, Lalani Carlton Jones, Michelle L. Kodet, Federico Cagnazzo and Niklas Lutzen 

CITATION: JNR Am J Neuroradiol. 2025 Aug 28:ajnr.A8966. doi: 10.3174/ajnr.A8966. Epub ahead of print.

ABSTRACT: CSF-venous fistulas are a common and increasingly recognized cause of spontaneous intracranial hypotension. Most CSF-venous fistulas occur in the thoracic spine and usually arise from nerve root sleeve diverticula. Myelography in the lateral decubitus position is necessary to detect and localize these fistulas, because this technique maximizes contrast density within diverticula, thereby permitting visualization of draining veins. Many modifications to decubitus myelography have been employed in an attempt to improve conspicuity of CSF-venous fistulas. In theory, maximizing the subarachnoid-venous pressure gradient during imaging should increase contrast flow through CSF-venous fistulas, improving detection of these sometimes-subtle leaks. Augmentation of intrathecal pressure through saline injection prior to myelography is a simple technique to achieve this and is common in many practices. However, only one prior case report has demonstrated the impact of pressurization on the visualization of a CSF-venous fistula. In this multi-institutional, retrospective case series, we report on a larger cohort of patients in whom CSF-venous fistulas were either occult or non-definite on myelography without saline pressurization and subsequently definitely seen on myelography with saline pressurization. While our study design precludes determining the incremental yield of saline infusion, it nonetheless provides further support of the value of saline pressurization during myelography in patients with suspected CSF-venous fistulas.

PMID: 40876944.
DOI: doi.org/10.3174/ajnr.A8966

AUTHORS: Christian Fung, Luisa Mona Kraus, Amir El Rahal, Levin Haeni, Florian Volz, Katharina Wolf, Mukesch Johannes Shah, Horst Urbach, Niklas Lützen, Jürgen Beck 

CITATION: Neurology vol. 105,6 (2025): e213998. doi:10.1212/WNL.0000000000213998

BACKGROUND AND OBJECTIVES: Chronic orthostatic headache after dural puncture is a serious condition lacking defined diagnostic criteria and pathophysiologic understanding. Prevailing opinion suggests CSF outflow through an unsealed dural hole after a lumbar puncture. We aimed to systematically search for a leak with MRI and perform dynamic CSF infusion testing in patients with chronic orthostatic headache after a lumbar puncture.

METHODS: In a retrospective, single-center cohort study at the Medical Center-University Hospital Freiburg, patients with chronic postdural puncture headache (cPDPH), defined by a history of dural puncture and new orthostatic headache either persisting >14 days after puncture and/or persisting after 1 or more epidural blood patches (EBPs), were included between April 2018 and July 2022. We excluded patients with proven spontaneous CSF leakage and those with previous interventions other than EBPs. Our workup included clinical data such as demographics, symptoms, prior treatment, and imaging data. We analyzed opening pressure and CSF dynamics by lumbar infusion test (LIT) including resistance to CSF outflow (RCSF), pressure at baseline and plateau, pulse amplitude at baseline and plateau, elastance, and pressure-volume index (PVI).

RESULTS: We included 21 consecutive patients with cPDPH in our final cohort. Complete data sets were available in 21 patients, of whom 19 were female and 2 were male. The median age was 39 years (interquartile range [IQR] 30-49 years). Spinal imaging showed pathologic extrathecal fluid in 2 patients (10%). After lumbar puncture, the median opening pressure was 12 cmH2O (IQR 9-17). LIT yielded a median RCSF of 10.77 mm Hg/(mL/min) (IQR 6.79-13.78), a median lumbar pressure baseline of 9.84 mm Hg (IQR 7.24-14.05), and a median PVI of 13.47 mL (IQR 9.62-18.47). There was no correlation between LIT parameters and symptom duration.

DISCUSSION: Our results do not support the hypothesis that all patients with cPDPH have a leaking dural defect or are in a state of CSF depletion. We conclude that symptoms may not be related to CSF dynamics as measured by opening pressure or with LIT and that further investigation into the pathomechanism of persisting orthostatic symptoms is warranted.

PMID: 40857657
DOI: 10.1212/WNL.0000000000213998

Note: please see this related letter by Dr. Jeremy K. Cutsforth-Gregory: Acute and Chronic CSF Dynamics Disorders Are Not the Same: Mechanistic Insights From Postdural Puncture Headache. No abstract is available, and therefore we have included it here instead of in a separate dropdown.

AUTHORS: Laisson De Moura Feitoza, Emanuele Orru’, Timo Krings, Neil V Patel 

CITATION: Neurology vol. 105,5 (2025): e214003. doi:10.1212/WNL.0000000000214003

ABSTRACT: A 69-year-old man presented with postural headaches after CT myelography (CTM) performed for evaluation of radiculopathy. CTM was complicated by inadvertent sub/epidural contrast injection. After conventional epidural blood patches failed to provide relief, he was treated for over 3 years with migraine medications. We obtained an MRI scan, now 3.25 years after symptom onset, showing signs of intracranial hypotension. Lateral decubitus CTM revealed a CSF-venous fistula (CSF-VF) corresponding to sub/epidural contrast distribution on initial CTM. Transvenous embolization of the CSF-VF was performed, and the patient’s headaches resolved within 48 hours.

This case demonstrates intracranial hypotension secondary to an iatrogenic CSF-VF, treated with transvenous embolization resulting in rapid and complete improvement of symptoms. Clinicians should be aware that sub/epidural injection of contrast can potentially cause CSF-VFs and that transvenous embolization has emerged as a minimally invasive therapy to treat this disease.

PMID: 40763337
DOI: 10.1212/WNL.0000000000214003

AUTHORS: Daphne Zhu, Peter G Kranz, Diogo G L Edelmuth, Joshua Lim, Soren Christensen, Ajay A Madhavan, Timothy J Amrhein 

CITATION: AJNR. American journal of neuroradiology, ajnr.A8972. 20 Aug. 2025, doi:10.3174/ajnr.A8972

BACKGROUND AND PURPOSE: Advancements in CT myelography (CTM) have improved visualization of CSF-venous fistulas (CVFs), a frequent cause of spontaneous intracranial hypotension (SIH). However, the relative impact of the timing of image acquisition and the contrast density in the subarachnoid space remains unclear. This study compared the effects of timing and contrast density in the ipsilateral subarachnoid space and assessed the impact of other technical factors on CVF conspicuity, using a validated instrument to stratify diagnostic confidence.

MATERIALS AND METHODS: A retrospective review of ICHD-3 confirmed SIH patients with CVFs was performed. Only fistulas classified as definite by the Duke CSF-Venous Fistula Confidence Score (DCCS) were included. All available CTMs covering each index fistula site were reviewed, excluding exams occurring after surgery or embolization for a definite CVF. We assigned a DCCS score to each acquisition and recorded contrast density in the subarachnoid space ipsilateral to the known CVF and image acquisition time. Patient positioning and scanner type were also collected as potential confounders. Ordinal logistic regression was used to assess associations with CVF conspicuity.

RESULTS: 144 patients with 149 definite CVFs comprised the final cohort, from which 222 CTMs and 697 acquisitions were assessed. Both increased contrast density and reduced acquisition time were associated with increased CVF conspicuity in univariate analyses (p<0.001). When adjusting for sex, scanner type, and patient positioning in the multivariate model, contrast density and time remained significant predictors of conspicuity (p<0.001). Density had a fourfold greater impact on conspicuity than time, with a 14.3% increase in likelihood of CVF detection per 100 HU increase in attenuation and an optimal target threshold at 836 HU.

CONCLUSIONS: Both contrast density and time influence conspicuity of CVFs on CTM; however, the greater relative impact of density suggests that myelogram technique should prioritize maximization of contrast density for optimal visualization of CVFs. Positioning strategies to increase local contrast pooling may improve CVF detection more effectively than timing adjustments alone.

PMID: 40835421 
DOI: 10.3174/ajnr.A8972

AUTHORS: J Ognard, G El Hajj, S Ghozy, J K Cutsforth-Gregory, A A Madhavan, R Kadirvel, D F Kallmes, W Brinjikji 

CITATION:Revue neurologique, S0035-3787(25)00589-2. 13 Aug. 2025, doi:10.1016/j.neurol.2025.08.002

🔓Open access! Full study available here.

BACKGROUND: Not only are diagnosis and management of spontaneous intracranial hypotension (SIH) challenging due to heterogeneous symptoms and limited treatment effectiveness, but SIH’s impact on health-related quality of life (HRQoL) is under-documented.

OBJECTIVES: In this systematic review, we aim to evaluate the assessment of QoL in SIH patients, identify impacted QoL domains, and explore treatment-related changes in QoL with a meta-analysis.

METHODS: Following PRISMA recommendations, we conducted a systematic literature search using a comprehensive set of keywords related to QoL and SIH. Databases were searched from the inception to July 2025. Studies were included if they provided reports on the quality of life for SIH patients. A meta-analysis using mean difference (MD) of baseline and after-treatment QoL scores was conducted. The risk of bias was assessed using the Newcastle-Ottawa scale.

RESULTS: Of 1435 initial publications, 20 studies met the inclusion criteria, representing a total of 1106 patients with SIH. EQ-5D-5L and HIT-6 were the most frequently used tools, with pooled results showing significant improvement post-treatment in perceived health (Visual analog scale score improved from 38.9 to 72.2; MD of 42.4 [95% CI 26.2-58.7]) and headache impact (HIT-6 scores improved from 66.1 to 49.3; MD of 20.1 [95% CI: 14.7-25.6]). Despite treatment, studies reported moderate to severe physical, mental, and social limitations.

DISCUSSION: The reporting of QoL is inconsistent and the tools used to assess QoL in SIH patients are heterogenous. While treatment provides help, some symptoms persist and highlight the need for specific QoL assessment, with tools tailored to SIH.

PMID: 40813174 
DOI: 10.1016/j.neurol.2025.08.002

AUTHORS: Ajay A Madhavan, Peter G Kranz, Michelle L Kodet, Lifeng Yu, Zhongxing Zhou, Timothy J Amrhein

CITATION: AJNR. American journal of neuroradiology, ajnr.A8938. 25 Jul. 2025, doi:10.3174/ajnr.A8938

ABSTRACT: Photon counting detector CT myelography is an effective modality for the localization of spinal CSF leaks. The initial studies describing this technique employed a relatively smooth Br56 kernel. However, subsequent studies have demonstrated that the use of the sharpest quantitative kernel on photon counting CT (Qr89), particularly when denoised with techniques such as quantum iterative reconstruction or convolutional neural networks, enhances detection of CSF-venous fistulas. In this clinical report, we sought to determine whether the Qr89 kernel has utility in patients with dural tears, the other main type of spinal CSF leak. We performed a retrospective review of patients with dural tears diagnosed on photon counting CT myelography, comparing Br56, Qr89 denoised with quantum iterative reconstruction, and Qr89 denoised with a trained convolutional neural network. We specifically assessed spatial resolution, noise level, and diagnostic confidence in eight such cases, finding that the sharper Qr89 kernel outperformed the smoother Br56 kernel. This was particularly true when Qr89 was denoised using a convolutional neural network. Furthermore, in two cases, the dural tear was only seen on the Qr89 reconstructions and missed on the Br56 kernel. Overall, our study demonstrates the potential value of further optimizing post-processing techniques for photon counting CT myelography aimed at localizing dural tears.ABBREVIATIONS: CNN = convolutional neural network; CVF = CSF-venous fistula; DSM = digital subtraction myelography; EID = energy integrating detector; PCD = photon counting detector; QIR = quantum iterative reconstruction.

PMID: 40713909  
DOI: 10.3174/ajnr.A8938

AUTHORS: Craig Schreiber, Gary Kocharian, Andrew Garton, Natasha Kharas, Bala McRae-Posani, Gayle Salama, Justin T Schwarz, Srikanth R Boddu, Jared Knopman, Y Pierre Gobin 

CITATION: Journal of neurointerventional surgery, jnis-2025-023686. 1 Aug. 2025, doi:10.1136/jnis-2025-023686

BACKGROUND: Endovascular transvenous embolization of spinal cerebrospinal fluid-venous fistulas (CVFs) has been shown in small studies to be a safe and effective treatment for spontaneous intracranial hypotension (SIH).

OBJECTIVE: To validate the safety and effectiveness of this procedure and to describe catheterization techniques available to safely perform these embolization procedures.

RESULTS: A total of 21 patients with confirmed CVF underwent 23 endovascular embolization procedures; 18 (86%) patients achieved both clinical and radiographic resolution of their SIH. There were no major neurologic complications from any procedure. One patient had postoperative pulmonary embolism and deep vein thrombosis. The most common side effects were prolonged symptoms of rebound intracranial hypertension (29%) and prolonged back pain with radiculopathy (24%). The azygous vein was used for catheterizing the level of interest in 83% of embolization procedures; the lumbar ascending vein was used for catheterization in 17% of the procedures; and direct catheterization of the segmental/foraminal vein at the level of interest was performed in 61% of the procedures. The epidural venous plexus was accessed and traversed to the level of interest in 39% of the procedures.

CONCLUSION: Endovascular transvenous embolization of CVF is a safe, well-tolerated, and effective treatment for SIH. Given the variability of the venous anatomy, there are multiple routes of catheterization that can be performed to access the level of interest when performing these procedures.

PMID: 40750348  
DOI: 10.1136/jnis-2025-023686

AUTHORS: Bala McRae-Posani, Andrew Kim, David Edasery, Sara Strauss, Michelle Roytman, John K Park, Gayle Salama

CITATION: Clin Neurol Neurosurg. 2025;255:108978. doi:10.1016/j.clineuro.2025.108978

OBJECTIVE: To report incidence, typology and treatment outcomes of spinal CSF leaks in patients with spontaneous intracranial hypotension (SIH).

METHODS: In this IRB approved study, consecutive SIH patients with myelogram-confirmed spinal CSF leak location, who underwent treatment between 2021 and 2023 at a single institution were retrospectively analyzed. The outcome variable was definitive treatment of SIH, defined as clinical and/or radiographic resolution of symptoms. Leak type classification was: Type 1 = ventral dural tear, Type 2 = lateral dural nerve root sleeve tear, Type 3 = CSF-venous fistula (CVF).

RESULTS: 32 SIH patients (average age 48 ± 15, 28 % male, 72 % female) were analyzed. A majority of them had a Type 1 CSF leak (59 %), followed by Type 3 (31 %) and Type 2 (9 %) leaks. Thoracic spine was the predominant location of the leaks (84 %); notably all CSF-venous fistulas were located there. Following trials of conservative management, all patients underwent treatment with EBP after leak site localization. 22/32 patients (69 %) had at least some resolution of symptoms following the first EBP. For 2/32 (6 %, both Type 2 leak), one targeted EBP provided definitive treatment. 30/32 (94 %, all leak types) had persistent clinical symptoms and had additional EBP(s). The mean number of EBPs per patient was 1.4 (range = 1-3). Following treatment failure of EBP(s), 10 patients with Type 3 leaks had transvenous embolization, which resulted in definitive treatment for 9 (90 %); 16 patients (leak Type 1 = 15, Type 2 = 1) had open dural surgery, which resulted in definitive treatment for 15 (94 %, all Type 1 leaks).

CONCLUSION: Overall, our analysis is consistent with recent data demonstrating that SIH incidence is higher among female patients and that CVFs are slightly more prevalent than previously reported, seen in nearly a third of our patients. Thoracic spine is the predominant location of CSF leaks; all our CVFs were located there. On treatment modalities, while EBP remains an important tool offering immediate symptom relief to SIH patients in the short term, permanent closure of the CSF leak and complete resolution of symptoms is rarely achieved with EBP. Definitive treatment is more likely with targeted endovascular and surgical modalities.

PMID: 40414053
DOI: 10.1016/j.clineuro.2025.108978

AUTHORS: Manou Overstijns, Amir El Rahal, Katharina Wolf, Niklas Lützen, Urs Würtemberger, Lucas Becker, Horst Urbach, Daniel Casanova Martinez, Jürgen Beck, Florian Volz 

CITATION: Brain & spine vol. 5 104320. 3 Jul. 2025, doi:10.1016/j.bas.2025.104320

🔓Open access! Full study available here.

INTRODUCTION: There is no accepted algorithm for the management of chronic subdural hematoma (cSDH) caused by spinal CSF leaks in spontaneous intracranial hypotension (SIH).

RESEARCH QUESTION: This study analyses characteristics of cSDH in SIH to establish a practicable management algorithm.

MATERIAL AND METHODS: This retrospective cohort study included all patients with spinal CSF leak closure from April 2018 to April 2024. Demographics, leak type, treatment modalities, as well as cSDH characteristics, prevalence, and risk factors were analyzed.

RESULTS: Among 272 SIH patients, 85 (31 %) concomitantly had cSDH, predominantly bilateral (88 %). Hematoma width ranged from 2 to 30 mm. cSDH prevalence was highest in CSF-venous fistulas (43 %), followed by ventral (31 %) and lateral leaks (22 %). Male sex (OR = 4; p < 0.001) and age >70 years (OR = 6; p = 0.008) were significant risk factors. Surgical evacuation was performed in 23 patients, with symptoms attributable to cSDH in 17/23 patients. The biggest cSDH without surgical treatment was 20 mm. No neurological deterioration occurred during diagnostics or treatment of CSF leaks. After leak closure, no cSDH, regardless of initial size or previous treatment, required additional treatment, and no recurrence occurred in the 3-month follow-up.

DISCUSSION AND CONCLUSION: Primary localization and targeted treatment of the spinal leak is safe in asymptomatic patients and cSDH ≤10 mm (“leak first” strategy). Immediate evacuation of the cSDH is mandatory in symptomatic patients (“subdural first” strategy). We consider the CSF leak closure as a causal treatment for cSDH resulting in a markedly low, close to zero, recurrence rate. Prospective validation of these findings is needed.

PMID: 40689141 
PMCID: PMC12272930 
DOI: 10.1016/j.bas.2025.104320

AUTHORS: Ajay A Madhavan, Timothy J Amrhein, Michelle L Kodet, Niklas Lutzen, Michael D Malinzak, Jeremy K Cutsforth-Gregory, Ian T Mark, Ivan Garza, Eike I Piechowiak, Lalani Carlton Jones  

CITATION: AJNR. American journal of neuroradiology, ajnr.A8900. 3 Jul. 2025, doi:10.3174/ajnr.A8900

ABSTRACT: CSF-venous fistulas are a common cause of spontaneous intracranial hypotension. Due to the more routine use of decubitus myelography and advancements in various imaging techniques, recognition of CSF-venous fistulas has increased in recent years. Most commonly, patients harbor only one fistula at the time of myelography (although additional de novo fistulas can arise after treatment). Occasionally, two synchronous CSF-venous fistulas may be seen on a single myelogram. The co-existence of more than two CSF-venous fistulas, however, is quite rare and has only been previously described in two instances. Here, we present a multi-institutional series of sixteen patients with three or more concurrently discovered CSF-venous fistulas, representing the largest cohort of such patients to date. We describe their clinical features, imaging findings, treatment approaches, and outcomes.ABBREVIATIONS: CVF = CSF-venous fistula; CB-CTM = cone beam CT myelogram; DSM = digital subtraction myelography; EID = energy integrating detector; SIH = spontaneous intracranial hypotension; PCD = photon counting detector.

PMID: 40571346 
DOI: 10.3174/ajnr.A8900 

AUTHORS: Danial Nasiri, Levin Häni, Johannes Goldberg, Thomas Petutschnigg, Tomas Dobrocky, Ralph T Schär, Christoph Schankin, Andreas Raabe, Jürgen Beck, Eike Immo Piechowiak, Christopher Marvin Jesse 

CITATION: AJNR. American journal of neuroradiology vol. 46,7 1486-1492. 1 Jul. 2025, doi:10.3174/ajnr.A8644

BACKGROUND AND PURPOSE: In patients diagnosed with spontaneous intracranial hypotension (SIH), microspurs are considered the culprit lesion in most ventral dural leaks (type I). The imaging characteristics of discogenic spurs, and their prevalence in the general population has not been reported in the literature.

MATERIALS AND METHODS: This observational case-control study was conducted comparing the prevalence and characteristics of discogenic microspurs between patients with SIH with a type I leak treated at a tertiary hospital between 2013 and 2023 and an age- and sex-matched cohort of trauma patients.

RESULTS: Each group consisted of 85 patients (mean age 51.6 ± 11.9 years), 74% (58/85 patients) were women. The prevalence of discogenic microspurs in the control group and SIH group was 31.8% and 90.6%, respectively. The mean length of the culprit microspur responsible for a dural leak was larger compared with the mean length of all coincidental microspurs from both the SIH and the control group not causing a dural leak (2.6 mm versus 1.6 mm, P < .001). Our multivariate logistic regression revealed that an increasing length of a microspur (OR, 1.942, CI 1.35-2.80, P < .001) and a narrower diameter of the spinal canal (OR, 0.85, CI 0.76-0.96, P = .008) were predictive for a dural tear.

CONCLUSIONS: A discogenic microspur is a common incidental finding and may be found in almost one-third of the general population. The length of the culprit microspur and the diameter of the spinal canal are distinct morphologic characteristics for type I associated CSF leaks.

PMID: 39788630 
DOI: 10.3174/ajnr.A8644

AUTHORS: Andrew L Callen, Daniel Montes, Debayan Bhaumik, Peter Lennarson, Mark D Mamlouk, Niklas Lützen, Jürgen Beck, Horst Urbach, Daniel Scoffings, David Butteriss, Lalani Carlton Jones 

CITATION: JNR Am J Neuroradiol. Published online June 20, 2025. doi:10.3174/ajnr.A8886

BACKGROUND AND PURPOSE: Spontaneous intracranial hypotension (SIH) due to lateral dural tears with spinal longitudinal extradural fluid collections (SLECs) can cause disabling orthostatic headaches. While epidural patching is commonly used as first-line treatment, outcomes specific to lateral dural tears have not been well characterized. We aimed to evaluate clinical and radiologic outcomes following CT-guided patching for lateral dural tears and assess whether anatomic or procedural factors- including presence of a herniated arachnoid pouch, patch volume, material, or approach-influence treatment success.

MATERIALS AND METHODS: This was a retrospective multicenter cohort study of patients with lateral dural tears treated with CT-guided epidural patching between December 2013 and March 2025. Demographics, leak characteristics, patching details, and clinical and imaging outcomes were collected. The presence of herniated arachnoid pouches on spine MRI and pre/post-treatment Bern scores were recorded. Associations between clinical resolution, SLEC resolution, and procedural variables were analyzed using univariate methods.

RESULTS: Fifty-six patients (mean age 38.7 ± 11.7 years; 80% female) were included. Mean pretreatment Bern score was 6.6 ± 2.3; no patients had superficial siderosis. Clinical resolution occurred in 20/56 (35.7%), and SLEC resolution in 10/40 (25%) on post-patch spine MRI. A herniated arachnoid pouch was present in 69.7% and associated with lower SLEC resolution (30% vs. 80%, p=0.003). Patch type, volume, transforaminal approach, and needle placement into the herniated pouch were not associated with outcomes. Post-patch Bern scores were lower among those with clinical resolution (0.9 ± 1.1 vs. 2.6 ± 2.5, p=0.046). Of 11 patients with complete clinical improvement who had post-patch spine MRI, 5 (45.5%) had persistent SLECs.

CONCLUSIONS: CT-guided patching led to complete symptom resolution in roughly one-third of patients with lateral dural tears. Herniated arachnoid predicted lower SLEC resolution, while procedural variables were not predictive of outcome. A subset of patients improved clinically despite persistent extradural fluid, emphasizing the need for long-term monitoring.ABBREVIATIONS: SIH＝ spontaneous intracranial hypotension; SLEC = spinal longitudinal extradural fluid collection.

PMID: 40541530 
DOI: 10.3174/ajnr.A8886 

AUTHORS: Angelique Sao-Mai S Tay, Marcel M Maya, Peter G Kranz, Ajay A Madhavan, Wouter I Schievink

CITATION:AJNR Am J Neuroradiol. Published online June 18, 2025. doi:10.3174/ajnr.A8884

BACKGROUND: Since the discovery of the cerebrospinal fluid venous fistula, its diagnosis has become more frequent, especially in patients with brain MRIs positive for spontaneous intracranial hypotension (SIH). However, there is a need to understand the likelihood of diagnosis of a cerebrospinal fluid venous fistula in a patient with negative brain imaging.

PURPOSE: Our aim was to investigate the frequency of cerebrospinal fluid venous fistula in patients suspected of SIH who have negative neuroaxis MRIs.

DATA SOURCES: All studies reporting on the incidence of cerebrospinal fluid venous fistula in patients with negative neuroaxis MRIs or low probability scores according to the Bern and Mayo score were searched on PubMed, EMBASE, Scopus, Web of Science and Cochrane.

STUDY SELECTION: Nine studies comprising of 898 patients suspected of SIH with 80 cerebrospinal fluid venous fistulas were included.

DATA ANALYSIS: Data were collected on patient demographics, number of patients found to have negative neuroaxis MRIs or low probability scores according to the Bern or Mayo scoring systems, type of imaging used, and number of patients diagnosed with cerebrospinal fluid venous fistula. Analysis was performed using the standard method for evaluating the negative predictive value of a diagnostic test.

DATA SYNTHESIS: There were 27 (10.7%) patients with a cerebrospinal fluid venous fistula of 252 patients found to have negative brain MRIs, 15 (18.3%) of 82 patients found to have low probability on the Bern score, and 38 (34.8%) of 109 patients found to have low probability on the Mayo score. The negative predictive value of a negative brain MRI was 0.89 (95%CI, 0.86-0.92), 0.81 (95% CI, 0.77-0.87) for the Bern score, and 0.65 (95% CI, 0.58-0.72) for the Mayo score.

LIMITATIONS: Our review was limited by heterogeneity of the reference standard and few studies in each subcategory.

CONCLUSIONS: This review demonstrated that a negative brain MRI is effective in predicting that a patient will not have a CVF, with a high NPV of 89%. However, a patient with a strong clinical suspicion for CSF leak should be considered for more invasive imaging.

PMID: 40533349 
DOI: 10.3174/ajnr.A8884

AUTHORS: Bala McRae-Posani, Ariana Thakurdyal, Marcus Konner, Craig Schreiber, David Edasery, Jared Knopman, Y Pierre Gobin, Gayle Salama  

CITATION: Neuroradiol J. Published online June 13, 2025. doi:10.1177/19714009251351292

ABSTRACT: Engorgement of spinal intradural veins on MRI has classically been associated with spinal dural arteriovenous fistulas (sdAVF). We report a novel case of a patient who presented with worsening cognitive impairment, whose spinal MRI demonstrated marked intradural venous engorgement in the form of serpiginous perimedullary flow voids akin to sdAVF. Further investigation led to a diagnosis of CSF-venous fistula (CVF), a sub-type of spontaneous spinal CSF leaks without an associated extradural fluid collection. This is the first reported case of CVF mimicking sdAVF on MRI. While clinical presentations of CVF and sdAVF are typically distinct, there may be overlap and/or uncertainty in atypical presentations, such as in our patient. As such, the differential for spinal intradural venous engorgement should be expanded to include spontaneous CSF leaks, including CVF.

PMID: 40514049 
PMCID: PMC12165954 
DOI: 10.1177/19714009251351292

AUTHORS: Olga Fermo

CITATION: Continuum (Minneap Minn). 2025;31(3):769-789. Doi: https://doi.org/10.1212/cont.0000000000001573

OBJECTIVE: Headache is the most common symptom of intracranial hypertension and hypotension and may not remit after normalization of intracranial pressure. This article reviews the clinical presentation, mechanism, differential diagnosis, treatment, prognosis, and monitoring of persistent headache after normalization of intracranial pressure in the setting of idiopathic intracranial hypertension and spontaneous intracranial hypotension.

LATEST DEVELOPMENTS: Erenumab, a monoclonal antibody to the calcitonin gene-related peptide receptor, was shown to reduce headache frequency in the first-ever prospective study of headache treatment in patients with idiopathic intracranial hypertension in ocular remission. Similar avenues remain to be explored for spontaneous intracranial hypotension even though it has been shown that some patients continue with headache despite radiographic resolution of CSF leaks.

ESSENTIAL POINTS: Headache is the most common symptom to herald an intracranial pressure disturbance and may not resolve despite normalization of pressure. Neurologists must be aware that persistent headache does not automatically imply abnormal intracranial pressure in patients with previous disorders of CSF dynamics and informed of the possible alternative headache etiologies in these populations.

PMID: 40459314 
DOI: https://doi.org/10.1212/cont.0000000000001573

AUTHORS: Jill C Rau, Jeremy K Cutsforth-Gregory 

CITATION: Continuum (Minneap Minn). 2025;31(3):644-667. doi:10.1212/CON.0000000000001566

OBJECTIVE: This article reviews the current understanding of the varied clinical presentations of spontaneous intracranial hypotension and discusses strategies and limitations in diagnosing this complex syndrome, including approaches for medical practitioners outside of specialty centers.

LATEST DEVELOPMENTS: Radiologic algorithms applied to brain MRI (eg, the Bern score) can help assess the probability of an underlying spinal CSF leak, but they do not replace good history-taking and clinical acumen. Brain MRI findings may evolve over time with or without leak-directed treatment. New techniques and improvements in imaging technology have led to better identification and classification of different types of spinal CSF leaks, especially CSF-venous fistulas that were reported for the first time in 2014 and now account for 50% or more of the leaks in patients without spinal extradural fluid collections. Occasionally, spontaneous intracranial hypotension is the result of preexisting intracranial hypertension causing “blowout” leaks.

ESSENTIAL POINTS: Spontaneous intracranial hypotension is caused by leakage of CSF from the spinal dura and most often presents with orthostatic headache, frequently accompanied by neck pain and stiffness, nausea, vestibulo-auditory distortions, visual changes, and other symptoms. Spontaneous intracranial hypotension can be debilitating, and long diagnostic and treatment delays are common. In rare cases, spontaneous intracranial hypotension can have dangerous sequelae, including superficial siderosis, subdural hematoma, bibrachial amyotrophy, brain sagging dementia, and even death. Early recognition of clinical symptoms and radiologic signs is imperative for best patient outcomes.

PMID: 40459308 
DOI: 10.1212/CON.0000000000001566

AUTHORS: Mark D Mamlouk, Anthony R Zamary, Niklas Lützen, Jürgen Beck, Adriana Gutierrez, Mark F Sedrak 

CITATION: AJNR Am J Neuroradiol. Published online May 29, 2025. doi:10.3174/ajnr.A8856

ABSTRACT: Spinal extradural arachnoid cysts are rare lesions that may result in compressive myelopathy. Their etiology is unclear, but they are thought to represent extradural collections due to a one-way dural defect from the subarachnoid space to the cyst. To date, identifying this dural defect on MRI and myelography have had limited and variable success. Surgery is the standard treatment for these cysts; however, there is debate whether total cyst removal is necessary versus dural repair alone. In this technical report, we show how dynamic decubitus CT and digital subtraction myelography can identify the dural defect and precisely guide the surgical approach. We also discuss many similarities between spinal extradural arachnoid cysts and lateral dural tear CSF leaks observed in patients with spontaneous intracranial hypotension and suggest they may represent a spectrum of CSF leaks.ABBREVIATIONS: SIH ＝ spontaneous intracranial hypotension; CTM ＝ CT myelography; DSM = digital subtraction myelography.

PMID: 40441881 
DOI: 10.3174/ajnr.A8856

AUTHORS: Wouter I Schievink, Marcel M Maya, William H Slattery

CITATION: JAMA Neurol. Published online May 27, 2025. doi:10.1001/jamaneurol.2025.1387

SUMMARY: An 8-year-old girl was seen in our clinic for cerebrospinal fluid (CSF) rhinorrhea, orthostatic headaches, and an acquired Chiari malformation. She had experienced 2 episodes of bacterial meningitis since age 6 years. The first episode of meningitis was complicated by cerebral edema with uncal herniation and a blown pupil requiring a decompressive craniectomy and subsequent autologous cranioplasty. This first episode of meningitis was due to Streptococcus pneumoniae, serotype 16F. The second episode of meningitis was due to nontypeable Haemophilus influenzae. She was diagnosed with an acquired Chiari malformation and underwent a decompressive craniectomy, cervical-1 laminectomy, and resection of the cerebellar tonsils at age 7 years. An underlying CSF leak was suspected because of the rhinorrhea and acquired Chiari malformation. A computed tomography (CT) cisternogram showed extensive amounts of contrast in the pterygoid muscles, soft palate, nasopharynx, and posterior paraspinal tissues, but no discrete source of the CSF leak was evident. The patient was referred to our medical center.

 PMID: 40423954 
DOI: 10.1001/jamaneurol.2025.1387

AUTHORS: Niklas Lützen, Florian Volz, Amir El Rahal, Katharina Wolf, Laura Krismer, Jürgen Beck, Horst Urbach, Charlotte Zander

CITATION: AJNR Am J Neuroradiol. Published online May 23, 2025. doi:10.3174/ajnr.A8847

BACKGROUND AND PURPOSE: Ventral dural tears (type 1 leaks) are reported to be the most common cause of spontaneous intracranial hypotension (SIH) and may require high dynamic myelography for detection. The aim of this cross-sectional study was to evaluate the temporal characteristics and diagnostic value of digital subtraction myelography (DSM) in type 1 leaks.

MATERIALS AND METHODS: Between April 2022 and August 2024, 104 consecutive patients with type 1 leaks were retrospectively identified. Institutional diagnostic standard included DSM as first-line examination; where deviating, patients were excluded. A previously described positioning technique of patients was used, enabling examination even in the challenging cervicothoracic junction of the spine. We evaluated the time for the contrast agent to first appear in the epidural space after reaching the level of the leak intrathecally, and the overall diagnostic yield of DSM.

RESULTS: 100/104 patients (49 women) were included. Mean age was 49 years (SD ± 11.9 years), mean BMI 24.8 (SD ± 4.29), and median Bern SIH score 4 (IQR 5). Type 1 leaks most commonly occurred at the T1/2 and T2/3 level (each 20/100), range C6/7-L1/2. The mean time for the contrast to be visible in the epidural space was on average 1.5 seconds (range 0-9 seconds) with 1 frame-persecond acquisition being sufficient for all but one patient. DSM as first-line investigation made the diagnosis in 76/100 patients, confirmed in all patients undergoing surgery (74/76). 24/100 patients required one or more subsequent dynamic CT-myelography (dCTM) for definite diagnosis another day, with 21/24 leaks confirmed at surgery. Bern SIH Score was significantly lower in dCTM compared to DSM group (3.25 vs 5; p=0.009), whereas age (p=0.548) and BMI (p=0.185) were not found to have an impact.

CONCLUSIONS: DSM demonstrated a high diagnostic yield for type 1 leaks when used as a first-line investigation. We have confirmed the high-flow characteristics of these leaks, suggesting that DSM’s high temporal resolution is ideally suited for their detection, with 1 frame-per-second being overall sufficient. A lower Bern SIH score could favor patients for primary use of dCTM, however, further research may clarify why DSM occasionally misses diagnoses.

PMID: 40409982
DOI: 10.3174/ajnr.A8847

AUTHORS: Niklas Lützen, Florian Volz, Amir El Rahal, Katharina Wolf, Laura Krismer, Jürgen Beck, Horst Urbach, Charlotte Zander

CITATION: AJNR Am J Neuroradiol. Published online May 23, 2025. doi:10.3174/ajnr.A8847

BACKGROUND AND PURPOSE: Ventral dural tears (type 1 leaks) are reported to be the most common cause of spontaneous intracranial hypotension (SIH) and may require high dynamic myelography for detection. The aim of this cross-sectional study was to evaluate the temporal characteristics and diagnostic value of digital subtraction myelography (DSM) in type 1 leaks.

MATERIALS AND METHODS: Between April 2022 and August 2024, 104 consecutive patients with type 1 leaks were retrospectively identified. Institutional diagnostic standard included DSM as first-line examination; where deviating, patients were excluded. A previously described positioning technique of patients was used, enabling examination even in the challenging cervicothoracic junction of the spine. We evaluated the time for the contrast agent to first appear in the epidural space after reaching the level of the leak intrathecally, and the overall diagnostic yield of DSM.

RESULTS: 100/104 patients (49 women) were included. Mean age was 49 years (SD ± 11.9 years), mean BMI 24.8 (SD ± 4.29), and median Bern SIH score 4 (IQR 5). Type 1 leaks most commonly occurred at the T1/2 and T2/3 level (each 20/100), range C6/7-L1/2. The mean time for the contrast to be visible in the epidural space was on average 1.5 seconds (range 0-9 seconds) with 1 frame-persecond acquisition being sufficient for all but one patient. DSM as first-line investigation made the diagnosis in 76/100 patients, confirmed in all patients undergoing surgery (74/76). 24/100 patients required one or more subsequent dynamic CT-myelography (dCTM) for definite diagnosis another day, with 21/24 leaks confirmed at surgery. Bern SIH Score was significantly lower in dCTM compared to DSM group (3.25 vs 5; p=0.009), whereas age (p=0.548) and BMI (p=0.185) were not found to have an impact.

CONCLUSIONS: DSM demonstrated a high diagnostic yield for type 1 leaks when used as a first-line investigation. We have confirmed the high-flow characteristics of these leaks, suggesting that DSM’s high temporal resolution is ideally suited for their detection, with 1 frame-per-second being overall sufficient. A lower Bern SIH score could favor patients for primary use of dCTM, however, further research may clarify why DSM occasionally misses diagnoses.

PMID: 40409982
DOI: 10.3174/ajnr.A8847

AUTHORS: Ioannis Vasilikos, Katerina Argiti, Kevin Joseph, Daniel Strahnen, Angeliki Stathi, Amir El Rahal, Florian Volz, Katharina Wolf, Mukesch Johannes Shah, Jürgen Beck, Horst Urbach, Niklas Lützen 

CITATION: Interv Neuroradiol. Published online May 21, 2025. doi:10.1177/15910199251339537

OBJECTIVES: Epidural blood patch (EBP) is the current standard of care for postdural puncture headache (PDPH). However, when EBP fails to provide relief, patients may experience discomfort and functional impairments. This study reports the safety and efficacy of a novel approach that uses autologous platelet-rich fibrin (PRF) as an alternative epidural patch.

METHODS: Sixty-seven patients with persistent PDPH symptoms after conservative medical treatment were screened. Among them, 12 (18%) patients underwent multiple EBP (range: 1–6), which failed to resolve the PDPH symptoms. As an alternative method, an epidural PRF patch (EPP) was used, in which PRF was injected percutaneously epidurally under fluoroscopic guidance. Patient symptoms were collected perioperatively, and a follow-up period of up to 6 months was conducted.

RESULTS: The 12 patients included showed good tolerance for the EPP procedure, with injection volumes ranging from 15 to 39 ml. Compared to EBP, patients reported a significant reduction in injection-associated pain, as measured by the unidimensional numeric rating scale, with a mean reduction of 52.8% (p ≤ 0.05). The headache impact test scores (HIT-6) obtained before and 6 months after EPP revealed a statistically significant reduction in symptoms by a mean of 33.3% (p ≤ 0.05). Moreover, no adverse effects were observed during follow up. It is noteworthy that all patients experienced significant relief from PDPH-associated symptoms 6 months after the intervention.

CONCLUSION: EPP may be a viable solution for patients with persistent PDPH symptoms. Notably, the discomfort experienced due to pain during the EPP procedure was markedly less than that experienced during the EBP procedure. The fact that clinical improvement was observed after 6 months is encouraging and lays the groundwork for additional clinical investigations.

PMID: 40398464 
PMCID: PMC12095222 
DOI: 10.1177/15910199251339537

AUTHORS: Malo Goapper, Liesjet E H van Dokkum, Vincent Costalat, Gaetano Risi, Lucas Corti, Olivia Portalier, Nicolas Lonjon, Emmanuelle Le Bars, Anne Ducros, Federico Cagnazzo

CITATION: J Headache Pain. 2025;26(1):120. Published 2025 May 19. doi:10.1186/s10194-025-02056-6

BACKGROUND: Transvenous Onyx embolization of cerebrospinal fluid-venous fistulas (CSFVF) is an emerging and effective treatment for symptomatic spontaneous intracranial hypotension (SIH). This condition significantly impacts patients’ quality of life (QoL) through a variety of debilitating symptoms.

METHODS: Patients were selected from a prospective database of individuals with CSFVF who underwent transvenous Onyx embolization. All participants were asked to complete 13 questionnaires assessing their QoL, before and three months after treatment. Clinical and radiological data were retrospectively collected from the database, and the impact of embolization was evaluated across multiple variables. Correlations and stepwise regression analyses were used to explore relationships between QoL and specific domains including headache, audio-vestibular and psychological symptoms, and spiritual well-being.

RESULTS: The study included 30 patients (mean age: 60.4 ± 14.1; female-to-male ratio: 2:1) diagnosed with SIH and CSFVF, that were treated successfully with Onyx embolization. There was no treatment-related morbidity. All 28 patients with headache reported symptom improvement, with 64% achieving complete resolution. The response rate was 100% for VAS-QoL, HIT-6, MIDAS grade, VAS-HI, and monthly headache days; lower rates were observed for SF-36 (56.6%), MSQ (96.7%), DHI and THI (90%), and psychological questionnaires (80-90%). Global QoL scores (VAS-QoL: p < 0.001, SF-36: p < 0.05) and QoL scores related to headache significantly improved post-treatment (HIT-6: p = 0.0119; MSQ: p = 0.0004; MIDAS: p = 0.0236). Psychological symptoms like depression and anxiety significantly decreased, while suicidal ideation resolved when present. Significant audio-vestibular QoL improvements were noted for dizziness (p = 0.002) and hearing disturbances (p = 0.021), but not for tinnitus (p = 0.101). MRI findings showed a significant reduction in SIH-related brain abnormalities (mean Bern-score: 6.3 ± 1.9 to 1.7 ± 1.5 post-treatment). However, changes in overall Bern-scores did not correlate with clinical variables, although brain sagging showed a trend toward correlation with headache intensity reduction (r = 0.37, p = 0.06).

CONCLUSION: CSFVF embolization is associated with significant radiological and clinical improvements, leading to enhanced global quality of life for patients with SIH.

PMID: 40389826 
PMCID: PMC12087204
DOI: 10.1186/s10194-025-02056-6

AUTHORS: Ajay A Madhavan, Michelle L Kodet, Waleed Brinjikji, Ian T Mark, Wouter I Schievink

CITATION: AJNR Am J Neuroradiol. Published online May 16, 2025. doi:10.3174/ajnr.A8820

ABSTRACT: Spinal CSF leaks are the primary cause of spontaneous intracranial hypotension, with the most common types of leaks including CSF-venous fistulas and dural tears.1 These leaks necessitate advanced myelographic techniques for accurate localization. Digital subtraction myelography is one such technique used at some institutions.2 Although digital subtraction myelography has excellent temporal and spatial resolution, it does not provide high-resolution cross-sectional images. Here, we describe our technique for conebeam CT myelography performed immediately after digital subtraction myelography, which generates high-resolution cross-sectional images.3-6 We illustrate how this technique enhances detection and characterization of some spinal CSF leaks.  

PMID: 40379460 
DOI: 10.3174/ajnr.A8820 

AUTHORS: Seyed Behnam Jazayeri, Mohammad Mirahmadi Eraghi, Julien Ognard, Sherief Ghozy, Ramanathan Kadirvel, Waleed Brinjikji, David F Kallmes

CITATION: AJNR Am J Neuroradiol. Published online May 16, 2025. doi:10.3174/ajnr.A8839

BACKGROUND: The efficacy and safety profiles of surgical and embolization techniques for cerebrospinal venous fistulas (CVFs) in patients with spontaneous intracranial hypotension (SIH) are not well-defined due to limited data and a lack of randomized trials.

PURPOSE: This systematic review and meta-analysis aims to compare the efficacy and safety of surgical treatment and transvenous embolization for CVFs in patients with SIH.

DATA SOURCES: PubMed, Embase, and Scopus were searched from inception to September 2024.

STUDY SELECTION: Clinical studies involving adults with confirmed CVFs, treated either surgically or through transvenous embolization, were included. Endpoints analyzed included headache response, overall symptom resolution, radiologic treatment response, and complications. Meta-analyses were performed using R software, applying random effects models to calculate prevalence rates and their 95% confidence intervals (CIs). Subgroups of surgery and embolization were compared using Chi-square test. The quality of the studies was assessed using appropriate checklists.

DATA ANALYSIS: Fifteen studies involving 321 patients and 354 CVFs were included, all of good quality. Both treatment modalities led to over 90% partial or complete headache response, with no significant difference between embolization (93.9%; 95% CI 88.3% to 96.9%) and surgery (90.1%; 95% CI 75.6% to 96.4%) (p=0.43). Overall symptom resolution (complete response) was also comparable between embolization (59.1%; 95% CI 50.5% to 67.1%) and surgery (70.7%; 95% CI 44.7% to 87.8%) (p=0.38). Radiologic response, measured by the Bern score, showed significant improvement post-embolization, with no corresponding data from surgical literature. The retreatment/recurrence rate was 14% (95% CI: 9.9% to 19.3%), with no significant difference between embolization (15.3%; 95% CI 10.3% to 22.1%) and surgery (11.3%; 95% CI 5.7% to 20.9%) (p=0.63). There was no publication bias among the reported endpoints.

LIMITATIONS: Lack of direct comparative effectiveness and small sample sizes heighten the risk of selection and confounding bias.

CONCLUSIONS: In conclusion, our systematic review and meta-analysis indicate that both surgical treatment and transvenous embolization for CVFs in patients with SIH provide comparable efficacy and safety profiles. Future research should employ uniform definitions, standardized radiologic and clinical endpoints, and long-term follow-up to more rigorously evaluate the relative efficacy and safety of these approaches.

PMID: 40379458
DOI: 10.3174/ajnr.A8839

AUTHORS: Javier L Galvan, Theodore W Hagens, Rola Saouaf, Wouter I Schievink, Marcel M Maya 

CITATION: AJNR Am J Neuroradiol. Published online May 16, 2025. doi:10.3174/ajnr.A8837

BACKGROUND: Spontaneous intracranial hypotension (SIH) often results from cerebrospinal fluid-venous fistulas (CVFs), and transvenous embolization is an effective treatment. Precise preprocedural venous mapping is crucial to optimize outcomes and mitigate risks.

PURPOSE: To evaluate the utility of Ferumoxytol-enhanced MR venography (MRV) in delineating venous anatomy for preprocedural planning in CVF treatment.

MATERIALS AND METHODS: This retrospective study included 57 participants referred for paraspinal venous embolization between July 2021 and February 2024. Participants were categorized into three groups: SIH with confirmed CVFs, SIH without identified CVFs, and behavioral variant frontotemporal dementia (bvFTD) without CVFs. All participants underwent Ferumoxytol-enhanced MRV to assess venous anatomy.

RESULTS: The cohort had mean age of 56.4 years (range, 18-86 years) and included 31 women and 26 men. Identified findings included a high prevalence of lumbar segmental veins draining directly into the inferior vena cava (93%), lumbar segmental veins draining into the left renal vein (54%), and incomplete ascending lumbar veins (63%). Other findings included a duplicated inferior vena cava (1.8%) and the pathological condition azygos vein stenosis (7%). Preprocedural MRV effectively identified venous variations, guiding tailored intervention strategies, and minimizing procedural risks.

CONCLUSIONS: Ferumoxytol-enhanced MRV provides comprehensive venous mapping, facilitating safer and more efficient planning for CVF treatment.

PMID: 40379457
DOI:10.3174/ajnr.A8837

AUTHORS: Timothy J Amrhein, Daphne Zhu, Linda Gray, Kayla W Kilpatrick, Al Erkanli, Jay Willhite, Michael D Malinzak, Peter G Kranz

CITATION: AJNR Am J Neuroradiol. Published online May 13, 2025. doi:10.3174/ajnr.A8835

BACKGROUND AND PURPOSE: CSF-venous fistulas (CVFs) are a common cause of spontaneous intracranial hypotension (SIH). CVF identification and localization are critical for diagnosis and treatment, but inconsistent visualization of CVFs on myelography leads to diagnostic uncertainty. Diagnostic confidence impacts treatment decisions. However, there is currently no standardized method for reporting the degree of confidence about the presence or absence of a CVF on CT myelography (CTM). The purposes of this study are to present a novel instrument to provide structured communication of the degree of certainty about the presence of a CVF, and to determine the inter-reader and intra-reader agreement of this scoring system for determining the presence of a CVF at a given spinal level on CTMs.

MATERIALS & METHODS: This retrospective study assessed the inter-reader and intra-reader reproducibility of a scoring system anchored in previously reported objective imaging findings, including the attenuation of paraspinal veins associated with CVFs. We included CTMs from patients with SIH performed between 10/2017-03/2024 at one institution. Exclusion criteria were CSF leak other than CVF, prior transvenous embolization, and non-diagnostic CTMs. Several potential iterations of the scoring system were developed. The study cohort consisted of a balanced set of cases representative of varying degrees of certainty: definite, high probability, low probability, and negative (25 each). Five radiologists (3-19 years experience) provided their blinded subjective confidence assessment and then applied the scoring system. Inter-reader and intra-reader agreements were calculated for the different scoring system models using kappa statistics.

RESULTS: The best-performing model produced substantial mean intra-reader agreement, closely approximated the number of definite CVFs, and was adopted as the final model. Inter-reader agreement for the adopted model was moderate, replicating that for the subjective interpretations. Other versions of the model produced fair-to-moderate inter-reader agreements and were not adopted.

CONCLUSIONS: We developed a structured reporting system anchored in objective imaging findings that communicates the degree of certainty about the presence of CVF on CTM. This system replicates assessments by expert readers and meets a critical need for improved communication both in daily clinical practice and in research by providing a method for objectively quantifying the certainty of CVF diagnosis.

PMID: 40360182 
DOI: 10.3174/ajnr.A8835 

AUTHORS: Charlotte Zander, Niklas Lützen, Alexander Rau, Katharina Wolf, Philipp Arnold, Hansjörg Mast, Amir El Rahal, Florian Volz, Petra Cimflova, Jürgen Beck, Horst Urbach, Theo Demerath 

CITATION: J Neurointerv Surg. Published online May 2, 2025. doi:10.1136/jnis-2024-022712

🔓Open access! Full study available here.

BACKGROUND: Cerebrospinal fluid (CSF) loss in spontaneous intracranial hypotension (SIH) is accompanied by volume shifts between the intracranial compartments. This study investigated tricompartimental and longitudinal volume shifts after closure of a CSF leak.

METHODS: Patients with SIH and suitable pre-therapeutic and post-therapeutic imaging for volumetric analysis were identified from our tertiary care center between 2020 and 2023. The Bern SIH score was calculated. Pre-interventional and post-interventional volumetry encompassed the CSF, parenchymal and venous compartments (ie, venous sinus and choroid plexus volumes).

RESULTS: In total, 32 patients with SIH (49.7±16.0 years, 22 women) met inclusion criteria. The mean SIH score decreased between baseline (4.5±2.7) and early (2.7±2.3, <7 days after intervention), and also late follow-up (1.4±1.7, follow-up ≥7 days) after leak closure. This was accompanied by a significant increase in ventricular volume from 22.1 to 25.0 mL (P=0.01) at early follow-up, and 23.9 mL at later follow-up (P=0.080). In contrast, venous sinus volumes decreased from 13.8 to 9.6 mL (P=0.016) at early follow-up, and 10.0 mL (P=0.007) at late follow-up. No significant change in mean choroid plexus, total gray or total white matter volume was observed.

CONCLUSIONS: Closure of a spinal CSF leak leads to an early increase in ventricular CSF volume and a decrease in venous sinus volume. The results reflect the long-term convergence of the SIH score to normal values and indicate that permanent closure of a CSF leak induces a stable recompensation of the intracranial compartments without involving significant volume shifts within the cerebral parenchyma.

PMID: 39870517
DOI: 10.1136/jnis-2024-022712

AUTHORS: Igor Santos Neto, Lídia Neves, Miguel Guimarães, Frederico Costa, Madalena Pinto, Osvaldo Sousa, Margarida Mota Freitas

CITATION: J Dance Med Sci. Published online April 22, 2025. doi:10.1177/1089313X251332726

INTRODUCTION: Spontaneous intracranial hypotension (SIH) is a condition caused by a cerebrospinal fluid (CSF) leak, leading to a drop in intracranial pressure. SIH typically results from a spontaneous dural tear, often linked to connective tissue disorders, minor trauma, or repetitive spinal stress. Among dancers, especially in professional ballet, the risk of SIH may be increased by repetitive spinal hyperextension and strenuous movements. Ballet movements, such as the cambré, place significant stress on the spine, potentially leading to CSF leaks. Recognizing the signs of SIH, which often presents with orthostatic headaches and lumbar pain, is critical for timely intervention and recovery, especially in athletes like dancers where functional recovery is paramount. 

METHODS: We report the case of a professional female ballet dancer who presented with severe orthostatic headache and lumbar pain after a hyperextension injury during a ballet performance. Brain magnetic resonance imaging revealed pachymeningeal enhancement and a CSF fistula at the T11 level, confirming a diagnosis of SIH. Conservative treatment, including bed rest, high fluid intake, and caffeine failed to relieve symptoms. Multiple blind blood patches and a fluoroscopically targeted patch were also unsuccessful. 

RESULTS: Definitive management was achieved via epidural patching with fibrin glue, which corrected the dural defect. A specialized physical therapy regimen focusing on spinal stabilization, core strengthening, and gradual reintroduction of dance-specific movements was essential for her recovery. This approach aimed to reduce the risk of recurrence and safely transition the patient back to dance.

CONCLUSION: SIH can result from hyperextension injuries in dancers, underscoring the importance of early diagnosis and multidisciplinary management. While conservative measures may fail in some cases, surgical correction, followed by a targeted rehabilitation program, plays a crucial role in full functional recovery. A rehabilitation program tailored to the demands of professional dancing is essential to minimize long-term complications and support a safe return to performance.  

PMID: 40260609
DOI: 10.1177/1089313X251332726

AUTHORS: Henrik W Schytz, Emil Smilkov, Ian Carroll, Tomas Dobrocky, Haidar M Al-Khazali, Daniel Tolnai, Rigmor H Jensen, Faisal Mohammad Amin

CITATION: Cephalalgia. 2025;45(4):3331024251325556. doi:10.1177/03331024251325556

🔓Open access! Full study available here.

ABSTRACT: BackgroundPersistent post-traumatic headache (PTH) is frequent, and intracranial hypotension may be an important cause of PTH. The present study aimed to examine whether magnetic resonance imaging (MRI) signs of intracranial hypotension are more frequent in people with persistent PTH than in healthy controls (HCs).MethodsAdults with persistent PTH attributed to mild traumatic brain injury and age- and sex-matched HCs attended a single non-contrast, brain MRI 3T session. Fluid attenuated inversion recovery T1- and T2-weighted sequences were acquired to assign a modified Bern score. The score ranges from 0 to 9 points, with higher scores indicating a greater probability of cerebrospinal fluid (CSF) leakage leading to intracranial hypotension. The primary outcome was the difference in modified Bern score between participants with persistent PTH and HCs. All images were examined by a certified neuroradiologist who was blinded to the group status.ResultsImaging data from 97 participants with persistent PTH and 96 age- and sex-matched HCs were eligible for analyses. A modified Bern score of ≤2 was present in 90 (93%) participants with persistent PTH and 85 (89%) HCs, indicating a low probability of CSF leak. None of the persistent PTH participants or the HCs had a score of >4. There were no significant differences in modified Bern scores between participants with persistent PTH and HCs.ConclusionsThere is a low prevalence of typical MRI Bern score signs of intracranial hypotension in PTH or HCs. Thus, intracranial hypotension is unlikely to be an underlying factor in persistent PTH attributed to mild traumatic brain injury.Trial RegistrationThe study was registered on ClinicalTrials.gov (identifier: NCT03791515). Date of registration 2018-12-29.  

PMID: 40255022
DOI: 10.1177/03331024251325556

AUTHORS: Diogo G L Edelmuth, Timothy J Amrhein, Peter G Kranz

CITATION: AJNR Am J Neuroradiol. 2025;46(4):832-839. Published 2025 Apr 2. doi:10.3174/ajnr.A8516

BACKGROUND AND PURPOSE: The conspicuity of CSF-venous fistulas (CVFs) on specialized myelographic imaging protocols varies, and the factors that determine their visibility have not yet been extensively studied. The purpose of this study was to determine the relative effect of 2 variables on CVF visibility: timing of imaging and intrathecal contrast attenuation.

MATERIALS AND METHODS: A retrospective cohort of 24 patients with spontaneous intracranial hypotension due to a CVF who underwent a total of 34 CT myelographies was studied. All CTM acquisitions that included the level of the known definite CVF were evaluated for 1) time passed after injection of contrast, 2) attenuation of the adjacent subarachnoid space, 3) subjective visibility of the CVF on that series, 4) attenuation of the corresponding draining vein, and 5) contrast dose used.

RESULTS: A total of 131 acquisitions included the level of the known CVFs. Attenuation values of the thecal sac were significantly higher in acquisitions where the CVFs were definitely visible (average 2283 HU) than in acquisitions where the CVFs were equivocal or not visible (764 HU and 583 HU, respectively). No significant difference was shown in the timing of the acquisitions between the 3 groups (12.8 minutes, 20.4 minutes, and 17.5 minutes, respectively). Multivariate linear regression showed thecal sac attenuation to be the only independent predictor of the attenuation of the CVF draining vein. Time passed after contrast injection was not independently correlated.

CONCLUSIONS: Intrathecal contrast attenuation has a strong positive relationship with the visibility of CVF. Timing of the acquisition was not an independent predictor of CVF visibility under our acquisition protocol.

PMID: 39349310  
PMCID: PMC11979859 (available on 2026-04-01)  
DOI: 10.3174/ajnr.A8516

AUTHORS: Andrew L Callen, Ashoke R Khanwalkar, Michael L Cunningham, Samantha L Pisani Petrucci, Debayan Bhaumik, Danielle Wilhour, Premal Trivedi, Peter Lennarson, David A Zander

CITATION: AJNR Am J Neuroradiol. Published online March 27, 2025. doi:10.3174/ajnr.A8760

ABSTRACT: This report presents a unique case of a 39-year-old female with a congenital unilateral aplasia of the middle cranial fossa floor associated with atypical hemifacial microsomia, initially described in a case report at age 14, who later developed a transosseous cerebrospinal fluid (CSF)-lymphatic fistula through the C1 vertebral body. Dynamic CT cisternography confirmed the diagnosis, and a transnasal percutaneous fibrin glue occlusion successfully reversed the patient’s brain sag and improved her symptoms. This case highlights the evolving understanding of CSF dynamics and the diagnostic and therapeutic challenges posed by rare CSF leak variants.ABBREVIATIONS: CSF = cerebrospinal fluid; SIH = spontaneous intracranial hypotension.  

PMID: 40147836
DOI:10.3174/ajnr.A8760

AUTHORS: Tony Zhang, Sara J Hooshmand, Nathaniel P Rogers Jr, David O Sohutskay, Michel Toledano, Ajay A Madhavan, John L Atkinson, Jeremy L Fogelson, Alejandro A Rabinstein, Jeremy K Cutsforth-Gregory, Rafid Mustafa 

CITATION: Mayo Clin Proc. Published online April 7, 2025. doi:10.1016/j.mayocp.2025.02.006

ABSTRACT: Spontaneous intracranial hypotension (SIH) is a clinical and radiologic syndrome caused by spinal leakage of cerebrospinal fluid due to a dural tear, leaking meningeal diverticulum, or cerebrospinal fluid-venous fistula. Whereas the hallmark clinical feature of SIH is orthostatic headache, in rare instances, life-threatening complications may include altered consciousness and even coma as a result of extreme downward displacement of the midbrain and brainstem. We describe the clinical features, neuroimaging findings, management strategies, and short-term outcomes of 2 unique cases of severe SIH and the role of Trendelenburg position to reverse coma. Both patients demonstrated remarkable recovery to normal mentation (Glasgow Coma Scale score of 15) within 1 hour of placement in Trendelenburg position and recurrence of coma if allowed to be upright. These cases serve to highlight the importance of this simple maneuver for acute management of severe SIH while awaiting definitive leak localization and treatment.  

PMID: 40196971
DOI: 10.1016/j.mayocp.2025.02.006

AUTHORS: Andrew L Callen, Samantha L Pisani Petrucci, Debayan Bhaumik, Peter Lennarson, Marius Birlea, Jennifer MacKenzie, Jodi Ettenberg, Lalani Carlton Jones

CITATION: AJNR Am J Neuroradiol. Published online March 26, 2025. doi:10.3174/ajnr.A8751

BACKGROUND AND PURPOSE: Dynamic myelography is a critical diagnostic tool for identifying cerebrospinal fluid (CSF) leaks, yet the current lack of standardized reporting can lead to variability in both clinical decision-making and patient understanding. To address these issues, we developed the Spontaneous Intracranial Hypotension Reporting and Data System (SIH-RADS), a standardized scoring system designed to categorize findings on dynamic myelography based on the degree of diagnostic certainty. We then administered a survey to patients and referring providers in order to evaluate the perceived value, clarity, and impact of SIH-RADS on patient and provider experiences as an adjunct to traditional reporting methods for dynamic myelography.

MATERIALS AND METHODS: The SIH-RADS scoring system was developed as a collaborative effort between patients and physicians, with six categories ranging from “Definite Positive with Precise Localization” (SIH-RADS 5) to “Technical Failure” (SIH-RADS 0). Surveys were distributed to three groups: (1) patients who had undergone myelography at our institution for suspected SIH, (2) anonymous patients via private spinal CSF leak groups on social media who had previously undergone myelography, and (3) referring providers who order myelograms for SIH evaluation. Survey questions assessed understanding of traditional reports, clarity of the SIH-RADS system, its impact on decision-making, and preferences for future reporting. Statistical comparisons between local and anonymous patient responses were performed using chi-square tests for categorical variables and t-tests for continuous variables. The observational study STROBE Checklist was utilized, with the proposed methodology followed.  

RESULTS: A total of 125 patients (78 local patients, 47 anonymous patients) and 13 providers participated in the survey. Among patients, 77% expressed a preference for SIH-RADS over traditional reporting methods, and 58% believed it would improve their understanding of myelography results. Among providers, 92% favored adopting SIH-RADS for future reports, with 85% rating it as very or extremely useful for guiding clinical decisions. 92% of providers reported that the standardized system would enhance communication with patients. Qualitative feedback emphasized the benefits of clearer categorization and actionable recommendations, while also highlighting opportunities to refine patient-facing language and address ambiguities in intermediate scores.  

CONCLUSIONS: A structured reporting system improves the perceived clarity, utility, and communication of dynamic myelography findings among both patients and providers.

PMID: 40139902
DOI: 10.3174/ajnr.A8751

AUTHORS: Andrew L. Callen, Samantha L. Pisani Petrucci, Peter Lennarson, Mark F. Sedrak, Adriana Gutierrez, Mark D. Mamlouk

CITATION: Radiology. 2025;314(3):e242194. doi:10.1148/radiol.242194 

ABSTRACT: Background Epidural blood patching is frequently used to treat spontaneous intracranial hypotension (SIH) due to cerebrospinal fluid leaks. However, its effectiveness in sealing ventral dural tears, particularly in chronic cases with organized spinal longitudinal extradural collections (SLECs), is not well documented. Purpose To assess the efficacy of intra-SLEC patching compared with traditional patching for treatment of ventral dural tears. Materials and Methods This two-site retrospective cross-sectional study conducted between January 2019 and July 2024 included patients with SIH due to a ventral dural tear who underwent epidural patching. Organized SLECs, characterized by sharply demarcated, convex edges and confined to the ventral epidural space, were distinguished from unorganized SLECs, which show fluid distribution in both ventral and dorsal spaces. The Fisher exact test was used to compare the complication rate between treatment groups, and the χ2 test was used to compare the proportion of patients with SLEC resolution between treatment groups. Results Fifty-two patients (mean age, 44.9 years ± 9.5 [SD]; 30 male patients) were included; before treatment, 39 had organized SLECs and 13 had unorganized SLECs. Overall, 25% (13 of 52) of patients had SLEC resolution after treatment. Organized SLECs were less likely to resolve than unorganized SLECs (six of 39 [15%] vs seven of 13 [54%]; P = .02). In patients with organized SLECs, intra-SLEC patching had a higher success rate (33%; five of 15) than traditional patching (4%; one of 24; P = .046). Multivariable analysis showed that intra-SLEC patching (odds ratio, 13.24 [95% CI: 1, 149]; P = .04) and unorganized SLECs (odds ratio, 21.47 [95% CI: 2, 216]; P = .009) were associated with higher odds of SLEC resolution. Conclusion In 25% of patients with SIH, MRI performed after epidural blood patching showed resolution of the SLEC. Intra-SLEC patching was more effective than traditional patching for treating organized SLECs. © RSNA, 2025 See also the editorial by Urbach in this issue.

PMID: 40131109
DOI: 2010.1148/radiol.242194

AUTHORS: Jennifer L Smith, Myoung J Kim, Linda Gray, Michael D Malinzak, Samantha Morrison, Amy P Stallings, Alaattin Erkanli, Peter G Kranz, Timothy J Amrhein

CITATION: AJNR Am J Neuroradiol. Published online March 20, 2025. doi:10.3174/ajnr.A8568

BACKGROUND AND PURPOSE: Fibrin glue is increasingly incorporated as a component in epidural blood patching (EBP) for the treatment of spinal CSF leaks. Hypersensitivity reactions are a potential complication of its use but are not well studied in the setting of EBP. The purpose of this study was to determine the incidence of hypersensitivity reactions to fibrin glue during EBP and to identify any predisposing factors associated with increased patient risk.

MATERIALS AND METHODS: A single-center retrospective cohort study with nested case-control design included patients who received fibrin glue EBP for the treatment of iatrogenic CSF leaks or spontaneous intracranial hypotension over 13 years. Patient demographics and multiple procedure-specific variables were collected. Cases were identified from the total cohort as those with hypersensitive reactions and matched with controls in a 1:3 ratio. The incidence of hypersensitivity reactions in the total cohort was calculated. Logistic regression models were fit to test for associations between variables and the development of a hypersensitivity reaction.

RESULTS: A total of 3065 CT-guided EBPs with fibrin glue were identified in 1574 individual patients. The incidence of hypersensitivity reactions was 0.49% per procedure and 0.95% per patient and never occurred during the first EBP with fibrin glue. Case-control analysis found higher odds for hypersensitivity reactions in patients with a lower BMI (OR 0.82 [0.71-0.96], P = .003), younger age (OR 0.95 [0.91-0.99], P = .011), and during procedures with inadvertent intravenous injections (OR 5.44 [1.34-22.01], P = .014).

CONCLUSIONS: We found a 0.49% incidence of hypersensitivity reactions during EBP with fibrin glue, none occurring during the first exposure. Younger age, lower BMI, and inadvertent intravenous injection during the procedure were associated with a higher likelihood of reactions. This study provides data useful for counseling patients on procedural risk and identifies variables for physicians to be aware of to help prevent life-threatening reactions to fibrin glue during EBP.

PMID: 40113253
DOI: 10.3174/ajnr.A8568

AUTHORS: Lucio Zeppa, Maria Laura Passaro, Amedeo Guida, Fabio Tortora, Carlo Petruzziello, Michele Rinaldi, Ciro Costagliola

CITATION: Eur J Ophthalmol. Published online March 13, 2025. doi:10.1177/11206721251321880

PURPOSE: Cerebrospinal fluid venous fistulas (CVFs) are a frequently underrecognized cause of cerebrospinal fluid (CSF) leaks, leading to intracranial hypotension and a wide range of symptoms, including visual disturbances. This case highlights the critical role of ophthalmologists in identifying CVFs as a cause of unexplained progressive vision loss.

METHODS: We present the case of a 45-year-old woman who developed progressive visual field loss over 15 years, ultimately resulting in blindness in one eye. Early neuroimaging and testing were normal despite symptoms of orthostatic headaches, photophobia, and hearing loss. Advanced imaging eventually identified a CVF at the T8 level. Surgical correction was performed, and the patient’s clinical response was assessed.

RESULTS: Surgical repair of the CVF led to clinical improvement, halting further progression of symptoms.

CONCLUSIONS: CVFs should be considered in patients with unexplained visual disturbances, particularly when accompanied by symptoms of intracranial hypotension. Early suspicion and collaboration with neurologists and neuroradiologists are essential for timely diagnosis and intervention. Ophthalmologists play a pivotal role in guiding appropriate referrals, ensuring multidisciplinary care to prevent irreversible visual and systemic complications.

PMID: 40080842
DOI: 10.1177/11206721251321880

AUTHOR: Mark D Mamlouk

CITATION: AJNR Am J Neuroradiol. 2025;46(3):597. Published 2025 Mar 4. doi:10.3174/ajnr.A8679

ABSTRACT: Fibrin glue patching can be an effective treatment for CSF-venous fistulas, along with transvenous embolization and surgical ligation.1,2 The technique differs from routine epidural patching, which is typically targeted in the dorsal or ventral epidural spaces. Instead, fibrin glue patching for CSF-venous fistulas is specifically targeted to the venous drainage pattern.3 There are 3 main locations to target: 1) the cyst-vein junction, 2) paravertebral “wall,” and 3) direct cyst puncture, and the goal is to sever the connection between the cyst and vein. In this video, technical tips for successful patching will be illustrated for these target locations.

PMID: 40037700
DOI: 2010.3174/ajnr.A8679

AUTHORS: Amir El Rahal, Katharina Wolf, Florian Volz, Jürgen Beck

CITATION: Oxf Med Case Reports. 2025;2025(2):omae182. Published 2025 Feb 22. doi:10.1093/omcr/omae182

🔓Open access! Full study available here.

BACKGROUND AND IMPORTANCE: Post-dural puncture headache (PDPH) is a well-recognized and frequently encountered complaint of Lumbar puncture. It usually resolves spontaneously over two weeks or with an epidural blood patch. Although known for a long time, PPDH could be linked to an arachnoidal bleb as a cause of cerebrospinal fluid (CSF) leakage. We report on surgical findings and impressive findings with low-flow CSF leakage in the context of an arachnoidal bleb.

CLINICAL PRESENTATION: We report a 42-year-old Neuroscientist with a 23-month history of positional headaches after a lumbar puncture (LP). Multiple Sclerosis was ruled out, but chronic orthostatic headache and tinnitus developed. Bed rest, caffeine tablets, IV hydration, and five high-volume epidural blood patches did not lead to improvement. However, brain fog and reduced ability to work ensued. A dynamic myelography did not reveal a CSF leak or a CSF-venous fistula, but a high-resolution T2Space Fat-saturated MRI detected an arachnoidal bleb at the alleged L3-L4 level. Microsurgical exploration identified the arachnoid bleb as a low-flow CSF leak. The video depicts Neomenbranes overlaying the dura mater appearing as a web and CSF oozing, washing a layer of blood away. CSF was leaking like a tear, and we had the impression of a weeping dura. Treatment involved bipolar shrinking, reinforcement of the dura and fibrin glue. The patient’s symptoms improved slowly post-surgery.

CONCLUSION: This case emphasises the importance of considering atypical causes of post-lumbar puncture complications, such as arachnoid blebs, and the role of surgery in identifying and treating these rare conditions.

PMID: 39990024
PMCID: PMC11845598
DOI: 10.1093/omcr/omae182 

AUTHORS: Daniel Montes, Samantha L Pisani Petrucci, Debayan Bhaumik, Nadya Andonov, Peter Lennarson, Andrew L Callen

CITATION: AJNR Am J Neuroradiol. Published online February 25, 2025. doi:10.3174/ajnr.A8720

BACKGROUND AND PURPOSE: Epidural patching with autologous blood and/or fibrin sealant is a common treatment for spinal cerebrospinal fluid (CSF) leaks, yet the factors influencing patch distribution remain poorly understood. This study aimed to analyze the craniocaudal (CC) and ventral epidural (VE) extent of epidural patch material and investigate the impact of variables such as patch volume, composition, spinal level of injection, and patient habitus on distribution patterns.

MATERIALS AND METHODS: This retrospective, cross-sectional cohort study included patients who underwent CT-guided epidural patching from January to September 2024. Inclusion criteria were age ≥18 years, dorsal interlaminar (DI) or transforaminal (TFO) epidural patching using blood, fibrin, or both, and immediate post-patch imaging capturing the entire patch extent. Patch distribution was assessed for CC and VE spread. Statistical analyses included linear and logistic regression models, with multivariate analyses adjusting for confounders.

RESULTS: Of 152 patients patched during the study period, 33 met inclusion criteria (mean age 45.4 years; 84.1% female) with 44 spinal levels patched: cervical (6.8%), thoracic (68.2%), and lumbar (25%). Mean patch volume (PV) per needle was 7.2 mL, with a mean CC spread of 4.6 spinal levels. There was a positive relationship between PV and CC spread across all spinal levels (β = 0.29, p = 0.001). Patches in the cervical region demonstrated the highest CC spread efficiency (0.77 levels/mL) compared to thoracic (0.56 levels/mL) and lumbar patches (0.47 levels/mL; p < 0.01). DI injections achieved greater CC spread but less VE dispersion than TFO injections (5.0 vs. 3.2 levels; p = 0.02; 58.8% vs 70.0%, p = 0.52). VE spread occurred in 61.4% of cases and followed a non-linear pattern along the spine, with an inflection point at T3.

CONCLUSIONS: The distribution of epidural patch material is influenced by spinal level, PV, composition, and injection approach. Cervical patches provide the greatest spread efficiency relative to volume, while DI approaches enhance craniocaudal spread but reduce ventral dispersion.

PMID: 40000121
DOI: 10.3174/ajnr.A8720

AUTHORS: Crystal H Kang, Ajay A Madhavan, John C Benson, Ian T Mark, Benjamin A Johnson-Tesch, Robert J McDonald, Jared T Verdoorn

CITATION:  AJNR. American journal of neuroradiology, ajnr.A8713. Advance online publication. https://doi.org/10.3174/ajnr.A8713

BACKGROUND AND PURPOSE: Probabilistic brain MRI scoring systems have been introduced to stratify the likelihood of identifying a CSF leak at myelography in spontaneous intracranial hypotension (SIH). The Bern scoring system by Dobrocky et al. is now well recognized, with a scoring system by Benson et al. introduced more recently (referred to as the “Mayo” score in this study). Neither of these scoring systems have been thoroughly evaluated in patients without SIH. The goal of this study was to evaluate these scoring systems in patients without SIH to understand the specificity of these MRI findings.

MATERIALS AND METHODS: We retrospectively reviewed normal brain MRIs performed in patients without clinically suspected SIH. Each examination was reviewed by one of four board-certified neuroradiologists with extensive experience in SIH, and all criteria of both scoring systems were evaluated and recorded.

RESULTS: 90 patients were included. Bern score was low probability in 78% and intermediate probability in 22%. Mayo score was low probability in 100%. Relatively high rates of positivity were seen in three specific Bern score parameters, including prepontine cistern effacement 5.0 mm or less (53%), decreased mammilopontine distance 6.5 mm or less (40%), and suprasellar cistern effacement 4.0 mm or less (28%). All intermediate probability Bern scores were due to suprasellar cistern effacement plus either or both prepontine cistern effacement and decreased mammilopontine distance. All other parameters of both scoring systems were either never or very rarely positive.

CONCLUSIONS: All intermediate probability Bern scores were due to decreased CSF cistern measurements, which had relatively high positivity rates in our non-SIH patient cohort. Due to substantial overlap with normals, these measurements are not specific indicators of “brain sag”, a hallmark imaging finding for SIH, and are not specific for SIH when the only “positive” brain MRI finding(s). The Mayo score is likely more specific for SIH with low probability scores in all patients in our cohort.

PMID: 39979026
DOI: 10.3174/ajnr.A8713

AUTHORS: Karen Buch, Aaron Paul, Neo Poyiadji, William A Mehan

CITATION: American journal of neuroradiology, 10.3174/ajnr.A8514. Advance online publication. https://doi.org/10.3174/ajnr.A8514

BACKGROUND AND PURPOSE: Patients with intracranial hypotension from spinal CSF leaks have increased choroid plexus volumes in response to CSF leakage. The purpose of this study was to assess changes in choroid plexus volumes in patients before and after spinal CSF leak repair.

MATERIALS AND METHODS: This was a retrospective, institutional review board-approved study on patients with spinal CSF leak who had pre- and post-CSF leak repair MRI examinations. Brain MRIs with contrast were performed on a 1.5/3T scanner with acquisition of 3D T1 postcontrast (eg, Bravo, MPRAGE, and so forth). Choroid plexus volumes at the level of the trigonum ventriculi were calculated for the left and right sides on all pre- and posttreatment MRIs using Visage-7 segmentation tools. Basic demographic data, type of CSF leak, and choroid plexus volumes were recorded for all patients. Basic 2-tailed t tests were used to compare choroid plexus volumes between the pre- and posttreatment groups.

RESULTS: Twenty patients with spontaneous intracranial hypotension from spinal CSF leaks were included. Eleven patients (55%) had a type 1a (ventral tear) spinal CSF leak, 5 patients (25%) had type 1b (lateral tear), and 4 patients (20%) had a type 3 spinal CSF leak. The mean age was 47.6 years (SD, 13.8 years). The mean choroid plexus volumes pretreatment were 0.82 cm3 (SD, 0.29 cm3) compared with 0.38 cm3 (SD, 0.19 cm3) posttreatment (P value 0.01).

CONCLUSIONS: Significantly decreased choroid plexus volumes were seen in patients with spontaneous intracranial hypotension following spinal CSF leak repair. This finding highlights the modulation and dynamic role of the choroid plexus in states of low CSF volumes.

PMID: 39979028
PMCID: PMC11979801 (available on 2026-03-01)
DOI: 10.3174/ajnr.A8514

AUTHORS: Federico Cagnazzo, Emmanuelle Le Bars, Gaetano Ris, Nicolas Lonjon, Liesjet E H van Dokkum, Lucas Corti, Vincent Costalat, Anne Ducros 

CITATION: Journal of neurointerventional surgery, jnis-2024-022957. Advance online publication. https://doi.org/10.1136/jnis-2024-022957

OBJECTIVE: To evaluate early and mid-term imaging and clinical outcomes following transvenous embolization of cerebrospinal fluid-venous fistulas (CSFVFs) in patients with spontaneous intracranial hypotension (SIH). 

METHODS: From November 2022 to November 2024, 60 consecutive patients with SIH and confirmed CSFVF underwent transvenous embolization using Onyx. Of these, 40 patients underwent brain MRI pre-treatment, 24 hours post-treatment, and at a 3-month follow-up. The primary outcome was regression of brain MRI abnormalities at 24 hours and 3 months. Secondary outcomes included rates of symptom improvement, predictors of clinical improvement, and complication rates.

RESULTS: The mean patient age was 61 years, and 65% were female. All procedures were technically successful. The median SIH score significantly decreased from 6 pre-treatment to 3.5 at 24 hours (P=0.01) and to 2 at 3 months (P=0.004). Early improvement in SIH score correlated with clinical improvement at 24 hours (P=0.002), which was observed in 77.5% of patients. Pachymeningeal enhancement (87.5%) and venous sinus engorgement (75%) were the most common MRI abnormalities. Both findings regressed in approximately 50% of patients at 24 hours and in 80% of patients at 3 months. At 3 months, 82.5% of patients achieved complete clinical recovery. Rebound post-treatment headaches occurred in 32.5% of patients but resolved within 7 days. The morbidity rate was 0%.

CONCLUSIONS: Transvenous embolization of CSFVFs results in early and sustained clinical and imaging improvements in patients with SIH. These findings support the efficacy of this intervention as a primary treatment for CSFVFs.

PMID: 39947894
DOI: 10.1136/jnis-2024-022957

AUTHORS: Linda D’Antona, Sanjay Cheema, Dwij Mehta, Fion Bremner, Laurence Dale Watkins, Ahmed Kassem Toma, Manjit Singh Matharu

CITATION: The journal of headache and pain, 26(1), 27. https://doi.org/10.1186/s10194-024-01928-7

🔓 Open access! Full study available here.

BACKGROUND: Spontaneous intracranial hypotension (SIH) is a debilitating disorder, with an estimated annual incidence of 3.7 per 100,000. Diagnosing SIH can be challenging for clinicians, as patients frequently present with normal investigation findings. Intracranial pressure (ICP) monitoring has been proposed as a valuable tool for patients with orthostatic headaches that are highly suggestive of SIH but have inconclusive investigation results. The primary objective of this study was to determine the proportion of patients with spontaneous orthostatic headaches and normal diagnostic work-up who exhibited abnormal ICP monitoring results.

METHODS: This single-centre, retrospective observational study was conducted at a tertiary referral centre specialising in SIH and CSF dynamics disorders. Consecutive patients with spontaneous orthostatic headaches and inconclusive diagnostic work-up who underwent 24-hour ICP monitoring were considered eligible. The 24-hour ICP monitoring followed a standardised protocol, measuring median ICP and pulse amplitude (a marker of brain compliance) during the daytime, nighttime, and over the entire 24-hour period. Specific cut-offs for low and high ICP states were predetermined based on the best available current evidence.

RESULTS: Thirty-eight patients (23 females, mean age 41 years ± 14SD) were identified. All patients had orthostatic headaches with a spontaneous onset. The mean duration of symptoms was 46 months ± 36SD. ICP monitoring identified 3 patients (7.9%) with low ICP (mean of the median 24-hour ICP – 2 mmHg ± 2SD) and 6 patients (15.8%) with high ICP (mean of the median 24-hour ICP 9 mmHg ± 3SD). Obvious CSF dynamics disturbances were excluded in the remaining 29 patients (76.3%, mean of the median 24-hour ICP 3 mmHg ± 3SD). The only clinical feature that was more common in patients with abnormal ICP compared to patients with normal ICP results was audiovestibular disturbance, namely aural fullness or muffled hearing (67% versus 17%, p = 0.015). There were no complications from the ICP monitoring procedure for any patient.

CONCLUSIONS: When appropriately selected, patients with a clinical picture highly suggestive of SIH, who have a negative diagnostic work-up, may benefit from consideration of invasive ICP monitoring. Moreover, a significant minority of patients with orthostatic headache may paradoxically have a high CSF pressure state, which can be detected using ICP monitoring.

MEETING PRESENTATIONS: Portions of this work were presented in abstract and oral presentation form at the Twenty-eighth Anglo-Dutch Migraine Association meeting (08/06/2018), the Tenth Meeting of the International Society for Hydrocephalus and Cerebrospinal Fluid Disorders (20/10/2018; Bologna, Italy), the Society of British Neurological Surgeons 2018 Autumn Meeting (19/09/2018; London, United Kingdom), and the European Association of Neurosurgical Societies 2023 congress (27/09/2023; Barcelona, Spain). This work is also part of the doctoral thesis of one of the authors (LD).

PMID: 39905291
PMCID: PMC11792413
DOI: 10.1186/s10194-024-01928-7

AUTHORS: Ian T Mark, Michael Oien, John C Benson, Jared Verdoorn, Ben Johnson-Tesch, D K Kim, Jeremy Cutsforth-Gregory, Ajay A Madhavan

CITATION: AJNR. American journal of neuroradiology, 46(1), 207–210. https://doi.org/10.3174/ajnr.A8437

ABSTRACT: Post-dural puncture headache is an increasingly recognized cause of chronic headache. Outside of clinical history and myelography that requires an additional dural puncture, there is no reliable diagnostic test to evaluate for persistent dural defects. We describe the injection of iodinated contrast into the dorsal epidural space under CT guidance in 5 patients as a potential tool to visualize persistent dural defects.

PMID: 39134368
PMCID: PMC11735425 (available on 2026-01-01)
DOI: 10.3174/ajnr.A8437

AUTHORS: Niklas Lützen, Jürgen Beck, Lalani Carlton Jones, Christian Fung, Theo Demerath, Alexander Rau, Charlotte Zander, Katharina Wolf, Florian Volz, Amir El Rahal, Horst Urbach

CITATION: Radiology, 314(2), e241653. https://doi.org/10.1148/radiol.241653

ABSTRACT: Background Type 2 lateral spinal cerebrospinal fluid (CSF) leakage occurs in approximately 20% of cases of spontaneous intracranial hypotension (SIH); however, the underlying pathologic mechanism remains ambiguous. Purpose To characterize MRI features of type 2 leaks, correlate them with intraoperative observations, and evaluate their diagnostic value. Materials and Methods Patients with SIH and type 2 leaks diagnosed between January 2021 and February 2023 were retrospectively identified. Characteristic imaging features from heavily T2-weighted MR myelography (T2-MRM) images were reevaluated (independently and blinded) in the type 2 leak sample mixed with a sample of 40 patients with SIH and type 1 (ventral) leaks. Available intraoperative data were reviewed for lateral dural tears, arachnoid outpouching, and ruptured spinal meningeal diverticula. Results Twenty-eight patients with SIH (mean age, 37.3 years ± 8.2 [SD]; 22 [79%] female patients) had 29 type 2 leaks between the T7 and L2 levels without side predominance. Characteristic cystic lesions with a broad dural base on the exiting nerve root sleeve were identified at T2-MRM; this “bud-on-branch” sign reflects an arachnoid outpouching herniating through a lateral dural tear, distinct from a meningeal diverticulum, which yielded a sensitivity of 79% (22 of 28; 95% CI: 59, 92) and a specificity of 100% (40 of 40; 95% CI: 91, 100) for leak location. Arachnoid outpouching was confirmed intraoperatively in 23 of 25 patients (92%; 95% CI: 81, 100), originating from the nerve root sleeve axilla in most patients (19 of 25, 76%; 95% CI: 59, 93); two of 25 patients (8%; 95% CI: 0, 19) had a dural tear only, and none had an underlying ruptured meningeal diverticulum. Conclusion This study showed that type 2 leaks are actually due to a lateral dural nerve root sleeve tear through which the arachnoid herniates, which contrasted the common perception that these leaks result from ruptured meningeal diverticula. These leaks had a characteristic anatomic distribution and MRI appearance with substantially facilitated leak localization in patients with SIH. 

PMID: 39932414
DOI: 10.1148/radiol.241653

CITATION: Cephalalgia : an international journal of headache, 45(1), 3331024241308154. https://doi.org/10.1177/03331024241308154

🔓 Open access! Full study available here.

AUTHORS: Dwij Mehta, Sanjay Cheema, Sophie Glover, Ayman M Qureshi, Indran Davagnanam, Salwa Kamourieh, Parag Sayal, Ahmed Toma, Susie Lagrata, Clare Joy, Callum Duncan, Jane Anderson, Brendan Davies, Paul J Dorman, Heather Angus-Leppan, James Walkden, Jonathan Rohrer, Manjit S Matharu

BACKGROUND: Orthostatic headache (OH) is a common feature of various conditions, including spontaneous intracranial hypotension (SIH), but no precise definition currently exists outlining the typical OH characteristics. This ambiguity risks misdiagnosis with unnecessary investigations and delay in institution of treatment. The present study aimed to carry out structured phenotyping of OH in patients with SIH with the aim of outlining its typical characteristics.

METHODS: Eligible patients with clinico-radiological confirmed SIH underwent a structured interview, after which a specialist interest group utilised the modified Delphi process to analyse the data and achieve consensus on defining the typical characteristics of OH in SIH.

RESULTS: In total, 137 patients were recruited. OH was present in 75.9%. Typical OH characteristics in SIH were defined as having a baseline severity (lying flat) on waking up of ≤3 (0-10, verbal response scale), headache onset-time of ≤4.5 h on becoming upright, time to peak severity of ≤7.5 h and an offset to baseline severity within 1.5 h of recumbency. Intra-individual consistency in the onset and offset-time was deemed a necessary characteristic.

CONCLUSIONS: Defining typical OH characteristics has the potential of enhancing SIH diagnostics and management, at the same time as minimising unwarranted invasive procedures.

PMID: 39781568
DOI: 10.1177/03331024241308154

AUTHORS: Peter J Lennarson, Andrew L Callen

CITATION: Neurosurgery clinics of North America, 36(1), 53–64. https://doi.org/10.1016/j.nec.2024.08.003

ABSTRACT: Cerebrospinal fluid (CSF) leaks are a challenging condition characterized by the loss of CSF, leading to severe orthostatic headaches and other debilitating symptoms. Diagnosis and management require a multifaceted approach involving clinical evaluation, imaging, and various treatment modalities to improve patient outcomes and quality of life.

PMID: 39542549
DOI: 10.1016/j.nec.2024.08.003

AUTHORS: Katharina Wolf, Florian Volz, Amir El Rahal, M Overstijns, Niklas Lützen, Charlotte Zander, Mukesch J Shah, Horst Urbach, Jürgen Beck 

CITATION: Headache. 2025;65(2):382-388. doi:10.1111/head.14882

🔓Open access! Full study available here.

BACKGROUND: Patients with spontaneous intracranial hypotension (SIH) report difficulties in concentration and memory. To objectify these deficits, we implemented standard cognitive tests into our routine SIH workup.

METHOD: Retrospective, single-center report of cognitive standard tests among patients with SIH consecutively admitted from May to July 2023. Cognitive testing involved the Montreal Cognitive Assessment (MoCA©, alternate versions, 0–30 points, 30 points for best performance, ≤26 indicating mild cognitive impairment at age >64 years), and the Trail Making Test, part B (TMT B, z-scores adjusted to age and education) to test for executive function. Both were administered at admission, and within 36–72 h after surgical repair of the spinal cerebrospinal fluid (CSF) leak.

RESULTS: A total of 18 patients with an active spinal CSF leak were tested at admission (seven with ventral, three with lateral leak, and eight with CSF-venous fistula). There was no profound brain sagging as described in brain sagging dementia. The mean (standard deviation [SD]) age was 53.6 (11) years. Bern scores ranged between 0 and 9, median 6.5. The mean (SD) MoCA score at admission was 26.5 (2) points, with five patients (28%) scoring <26 points indicative of mild cognitive impairment. Performance in the TMT B was impaired in nine patients (50%, z-score ≥2). Upon targeted treatment of the CSF leak, the mean (SD) MoCA score immediately improved to 28.5 (1), p = 0.001 (n = 14), as did performance on the TMT B (mean [SD] 2.1 [2] vs. 1.1 [1], p = 0.015, n = 13).

DISCUSSION: Spontaneous intracranial hypotension with an active spinal CSF leak is associated with cognitive impairment and surgical closure of the leak led to rapid improvement. We conclude that there may be a causal relationship between cognitive dysfunction and spinal CSF loss. We suggest considering spinal CSF leaks as a treatable cause in patients with mild cognitive impairment and with pre-dementia. This may ultimately necessitate thorough screening of brain and spine magnetic resonance images in patients with mild cognitive impairment.

PMID: 39676275 
PMCID: PMC11794966 
DOI: 10.1111/head.14882

AUTHORS: Charlotte Zander, Niklas Lützen, Alexander Rau, Katharina Wolf, Philipp Arnold, Hansjörg Mast, Amir El Rahal, Florian Volz, Petra Cimflova, Jürgen Beck, Horst Urbach, Theo Demerath

CITATION: Journal of neurointerventional surgery, jnis-2024-022712. Advance online publication. https://doi.org/10.1136/jnis-2024-022712

BACKGROUND: Cerebrospinal fluid (CSF) loss in spontaneous intracranial hypotension (SIH) is accompanied by volume shifts between the intracranial compartments. This study investigated tricompartimental and longitudinal volume shifts after closure of a CSF leak.

METHODS: Patients with SIH and suitable pre-therapeutic and post-therapeutic imaging for volumetric analysis were identified from our tertiary care center between 2020 and 2023. The Bern SIH score was calculated. Pre-interventional and post-interventional volumetry encompassed the CSF, parenchymal and venous compartments (ie, venous sinus and choroid plexus volumes).

RESULTS: In total, 32 patients with SIH (49.7±16.0 years, 22 women) met inclusion criteria. The mean SIH score decreased between baseline (4.5±2.7) and early (2.7±2.3, <7 days after intervention), and also late follow-up (1.4±1.7, follow-up ≥7 days) after leak closure. This was accompanied by a significant increase in ventricular volume from 22.1 to 25.0 mL (P=0.01) at early follow-up, and 23.9 mL at later follow-up (P=0.080). In contrast, venous sinus volumes decreased from 13.8 to 9.6 mL (P=0.016) at early follow-up, and 10.0 mL (P=0.007) at late follow-up. No significant change in mean choroid plexus, total gray or total white matter volume was observed.

CONCLUSIONS: Closure of a spinal CSF leak leads to an early increase in ventricular CSF volume and a decrease in venous sinus volume. The results reflect the long-term convergence of the SIH score to normal values and indicate that permanent closure of a CSF leak induces a stable recompensation of the intracranial compartments without involving significant volume shifts within the cerebral parenchyma.

PMID: 39870517
DOI: 10.1136/jnis-2024-022712

AUTHORS: Ajay A Madhavan, Vinil Shah, J Levi Chazen, Waleed Brinjikji, Jeremy K Cutsforth-Gregory, Thien Huynh, Ben A Johnson-Tesch, Ian T Mark, Darya P Shlapak, Mark D Mamlouk

CITATION: AJNR. American journal of neuroradiology, 46(2), 421–425. https://doi.org/10.3174/ajnr.A8507 

ABSTRACT: CSF-venous fistulas (CVFs) are a common and increasingly recognized type of spinal CSF leak. Most of these fistulas occur in the setting of spontaneous intracranial hypotension, though nonspontaneous cases have been described as well. In most instances, CVFs arise from the dome or neck of nerve root sleeve diverticula (also called meningeal diverticula). Venous drainage typically involves some combination of the internal epidural venous plexus and external vertebral venous plexus. Not uncommonly, venous drainage into the basivertebral venous plexus or other intraosseous veins can be seen. However, the drainage is usually a secondary finding related to normal communication between intraosseous and extraosseous veins. We have recently observed unique cases in which CVFs arise directly within the vertebral elements, resulting in primarily intraosseous drainage. It is possible that this phenomenon is secondary to prominent meningeal diverticula remodeling the adjacent vertebral elements. In this clinical report, we reviewed a multi-institutional series of CVFs exhibiting primary intraosseous drainage, with the goal of illustrating the imaging findings, treatment strategies, and outcomes of the patients. Nine cases were identified demonstrating this phenomenon. We show that intraosseous CVFs can arise in virtually any part of the vertebrae and describe how this feature affects

PMID: 39884834
DOI: 10.3174/ajnr.A8507

AUTHORS: Lalani Carlton Jones, Diogo G.L. Edelmuth, David Butteriss and Daniel J. Scoffings

CITATION: AJNR. American journal of neuroradiology, 46(1), 211–218. https://doi.org/10.3174/ajnr.A8445

ABSTRACT: Patients with spontaneous intracranial hypotension caused by type 1 dural defects typically have an epidural fluid collection on MRI. Still, the location of the defect is not usually readily identifiable on standard MRI sequences and can be at any point along the length of the collection. The most common location for type 1 leaks is ventral and, as such, these are most commonly associated with ventral predominant epidural fluid. Dynamic myelography (either digital subtraction myelography or dynamic CT myelography) is currently the standard of care for localizing the defect. We describe an imaging sign on T2-weighted images caused by CSF-flow egress at the site of the defect that may permit accurate prediction of the site of the CSF leak noninvasively. Importantly, this sign was only observed on 2D T2-weighted and STIR images and not on 3D acquisitions, which notably suppress artifacts. This has implications for optimal MRI spine protocol construction. This sign can be used to limit myelographic range, reduce radiation dose, and increase diagnostic confidence in dural defect location.

PMID: 39134372
PMCID: PMC11735451 (available on 2026-01-01)
DOI: 10.3174/ajnr.A8445