Publication abstracts about spinal CSF leak from 2026

AUTHORS: Michelle L Wegscheid, Zack Nigogosyan, Arindam R Chatterjee, Cyrus A Raji, Martin N Reis, Nicholas P Fleege, Sherwin N Azad, Benjamin A Plog, John Ogunlade, Ananth K Vellimana, Manu S Goyal, Arash Nazeri  

CITATION: Headache, 10.1111/head.70123. 6 May. 2026, doi:10.1111/head.70123

OBJECTIVE: This retrospective, single-center, descriptive case series evaluates early adoption of a two-stage spine MRI protocol incorporating high-resolution, three-dimensional mesoscale constructive interference in steady state (meso-CISS) for targeted cerebrospinal fluid (CSF) leak localization.

BACKGROUND: Spontaneous intracranial hypotension (SIH) results from CSF leaks at the spinal canal, yet precise localization of dural defects remains challenging. Although fat-saturated heavily T2-weighted magnetic resonance (MR) myelography (HT2-MRM) is sensitive to spinal longitudinal extradural CSF collections (SLECs), it does not reliably localize the leak site.

METHODS: Thirty-six consecutive patients with suspected SIH underwent a standardized total spine MRI protocol, including three-dimensional HT2-MRM for SLEC screening at Barnes-Jewish Hospital/Washington University School of Medicine between December 2023 and November 2025. In 11 SLEC-positive cases, meso-CISS was performed for targeted high-resolution leak localization.

RESULTS: Among the 10 patients with SIH with interpretable meso-CISS imaging, findings consistent with dural defects were visualized in six (0.5-8 mm in size), with additional supportive features suggestive of dural defects identified in three patients. Compared with HT2-MRM, meso-CISS provided higher spatial detail, allowing clearer delineation of dural defects.

CONCLUSION: A two-stage spine MRI protocol incorporating HT2-MRM and meso-CISS may aid in the noninvasive localization of dural defects in SIH. Meso-CISS provides high spatial resolution for visualization of small dural defects and associated pathology. Larger studies are required to clarify how this approach may be incorporated into existing diagnostic workflows for spinal CSF leak localization.

PMID: 42089545  
DOI: 10.1111/head.70123

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

CITATION: Laryngo- rhino- otologie vol. 105,5 (2026): 286-296. doi:10.1055/a-2724-7080

BACKGROUND: Spontaneous intracranial hypotension (SIH) remains an underdiagnosed condition despite increasing awareness due to recent scientific advances. Diagnosis can be delayed by the broad clinical presentation and imaging pitfalls. This results in a high degree of physical impairment for patients, including social and psychological sequelae as well as long-term damage in the case of delayed diagnosis and treatment.

METHOD: The study is based on a selective literature search on PubMed including articles from 1990 to 2023 and the authors’ clinical experience from working in a CSF center.

RESULTS AND CONCLUSION: SIH mostly affects middle-aged women, with the primary symptom being position-dependent orthostatic headache. In addition, there is a broad spectrum of possible symptoms that can overlap with other clinical conditions and therefore complicate the diagnosis. The causative spinal CSF loss can be divided into three main types: ventral (type 1) or lateral (type 2) dural leak and CSF-venous fistula (type 3). The diagnosis can be made using a two-stage workup. As a first step, noninvasive MRI of the head and spine provides indicators of the presence of SIH. The second step using focused myelography can identify the exact location of the cerebrospinal fluid leak and enable targeted therapy (surgical or interventional). Intrathecal pressure measurement or intrathecal injection of gadolinium is no longer necessary for primary diagnosis. Serious complications in the course of the disease can include space-occupying subdural hematomas, superficial siderosis, and symptoms of brain sagging, which can lead to misinterpretations. Treatment consists of closing the dural leak or the cerebrospinal fluid fistula. Despite successful treatment, a relapse can occur, which highlights the importance of follow-up MRI examinations and emphasizes the chronic nature of the disease. This paper provides an overview of the diagnostic workup of patients with suspected SIH and new developments in imaging and therapy.

PMID: 42081897  
DOI: 10.1055/a-2724-7080

AUTHORS: Lachlan S W Knight, Rachel L Smith, Alexis Ceecee Britten-Jones, Sam E John, David B Grayden, Bang V Bui, Lauren N Ayton, Bao N Nguyen 

CITATION: Journal of neurology vol. 273,5 300. 30 Apr. 2026, doi:10.1007/s00415-026-13840-y

🔓Open access! Full study available here. 

BACKGROUND: Spinal cerebrospinal fluid (CSF) leak is a disabling and often misdiagnosed condition characterised by CSF hypovolemia. Associated neurological symptoms are diverse and often leave individuals bed-bound due to their orthostatic nature. Prior literature describing the difficulties in diagnosis, treatment, and ongoing impact of CSF leak is, thus far, confined to Europe and North America. This study provides a novel account of lived experiences of spinal CSF leak in Australia and Aotearoa New Zealand (NZ).

METHODS: An online survey exploring symptoms, diagnosis, treatment, and effect on daily life of a person’s “first” CSF leak was designed with consumer involvement. Responses were received from May to August 2025. Open-text responses were analysed using thematic analysis.

RESULTS: In total, 106 surveys were completed. Over 70 symptoms were reported; the most common were orthostatic headache (95.3%), neck pain (85.8%), and brain fog (79.2%). Most people considered their diagnosis (73.6%) and treatment (65.3%) difficult, underscored by limited clinician awareness and access to care, leaving individuals to self-advocate. Amongst symptomatic participants (73.6%), median EuroQol Visual Analogue Scale score was 40 (interquartile range 25-64; indicating low health-related quality-of-life) and mean Headache Impact Test-6 score was 69 ± 5 (indicating severe impact). Other challenges identified included navigating change to social identity and daily functioning.

CONCLUSIONS: The spinal CSF leak experience in Australia and NZ is comparable to reports from other high-income countries, highlighting the global need to increase awareness of spinal CSF leak, support timely diagnostic, referral and treatment pathways, and mitigate its impact on quality of life.

PMID: 42062596  
PMCID: PMC13132889  
DOI: 10.1007/s00415-026-13840-y

AUTHORS: Guilherme M Silva, Vinicius R Brambilla, Diogo G L Edelmuth 

CITATION: AJNR. American journal of neuroradiology, ajnr.A9383. 29 Apr. 2026, doi:10.3174/ajnr.A9383

BACKGROUND AND PURPOSE: Cerebrospinal fluid-venous fistulas (CVFs) are a major cause of spontaneous intracranial hypotension (SIH) and are best detected with lateral decubitus-CT myelography (LD-CTM) and lateral decubitus-digital subtraction myelography (LD-DSM). On LD-CTMs, we have often noticed an accessory dural sleeve (ADS) separate from the nerve root sleeve, a previously underrecognized imaging finding. The purpose of this study is to describe the imaging appearance of the ADS and its relationship to CVFs.

MATERIALS AND METHODS: Retrospective single-center review of LD-CTM examinations performed between August/2019 and December/2025 for suspected CVF, evaluated for: 1) Presence, location, size and morphology of an ADS; 2) Visibility of a radicular vein in relationship to the ADS; 3) relationship of ADSs to CVFs (when present). ADSs were defined as independent dural projections separate from nerve root sleeves. Morphologic classification (infundibular, linear, diverticular) was based on objective length and diameter criteria. Associations between ADS presence, clinical status, and CVF location were assessed using descriptive statistics, chi-square testing, and permutation-based simulation.

RESULTS: 91 LD-CTMs from 59 patients were analyzed. 53 ADSs were identified in 33 patients (55.9%; 95% CI, 43.3%-67.9%), most commonly in the thoracic spine. A radicular vein was seen traversing the ADS in 49.1% of cases. Regarding morphology, 22 were infundibular (41.51%), 18 linear (33.96%) and 13 diverticular (24.53%). Only in 2 cases, the CVF originated from the ADS (6% of CVFs). Co-occurrence of ADS and CVF at the same level and side occurred more often than expected by chance with approaching statistical significance (p = 0.059), but ADS location demonstrated limited predictive value for CVF localization.

CONCLUSIONS: ADSs are a common anatomic variant encountered on LD-CTMs that may mimic CSF leaks, particularly CVFs, and only rarely represent true CVFs. Recognition of ADS morphology and reliance on dynamic contrast behavior are essential to avoid false-positive diagnoses. Linear and diverticular morphologies were more likely to resemble fistulas. ADS: accessory dural sleeve; CSF: cerebrospinal fluid; CVF: cerebrospinal fluid-venous fistula; ICHD-3: International Classification of Headache Disorders, Third Edition; LD-CTM: lateral decubitus CT myelography; LD-DSM: lateral decubitus-digital subtraction myelography; SIH: spontaneous intracranial hypotension.

PMID: 42055959  
DOI: 10.3174/ajnr.A9383

AUTHORS: Bikei Ryu, Timo Krings, Neil V Patel, Jonathan Pace, Emanuele Orru 

CITATION: AJNR. American journal of neuroradiology, ajnr.A9384. 29 Apr. 2026, doi:10.3174/ajnr.A9384

BACKGROUND AND PURPOSE: Transvenous embolization (TVE) is an effective treatment for cerebrospinal fluid-venous fistulae (CVFs) causing spontaneous intracranial hypotension. During TVE the precise site of intrathecal-intravascular fistulization is not visualized; the standard approach entails extensive embolic casting to improve the likelihood of CVF obliteration. We sought to define the imaging-based location of the fistulous point relative to the intervertebral foramen and to determine whether foraminal topography differs by CVF morphology.

MATERIALS AND METHODS: We retrospectively reviewed 29 consecutive patients with CVF-positive CT myelography. CVFs were classified as diverticular or non-diverticular based on whether the draining vein originated from a meningeal diverticulum. The visualized fistulous point (origin of the draining vein on CT myelography) was mapped onto a standardized foraminal schematic to characterize its distribution in 3 planes.

RESULTS: Meningeal diverticula at the CVF level were present in 24/29 (82.8%) cases. Fourteen (48.3%) CVFs were diverticular and 15 (51.7%) were non-diverticular. In the axial plane, diverticular CVFs most frequently localized to the ventrolateral foramen (10/14, 71.4%), whereas non-diverticular CVFs most frequently localized to the ventromedial foramen (9/15, 60%) (p=.001). In the sagittal plane, most fistulous points (69.0%) localized to the anterosuperior foraminal quadrant; this distribution did not differ by CVF type (p=.96). In non-diverticular CVFs, the fistulous point was located along the normal-appearing nerve root sleeve (8/15, 53.3%) or on the spinal canal dura (7/15, 46.7%).

CONCLUSIONS: CVFs demonstrate a reproducible foraminal topography on CT myelography that varies by morphology: diverticular fistulae more often localize ventrolaterally, whereas non-diverticular fistulae favor ventromedial locations. Across types, fistulous points most commonly lie in the anterosuperior foraminal quadrant. These imaging landmarks may help inform procedural targeting during TVE and transforaminal fibrin glue injection.

PMID: 42055957 
DOI: 10.3174/ajnr.A9384

AUTHORS: Florian Volz, Mazin Omer, Manou Overstijns, Amir El Rahal, Marc Hohenhaus, Jan-Helge Klingler, Niklas Lützen, Horst Urbach, Charlotte Zander, Ian Carroll, Jürgen Beck, Katharina Wolf

CITATION: Cephalalgia : an international journal of headache vol. 46,4 (2026): 3331024261444662. doi:10.1177/03331024261444662

🔓Open access! Full study available here. 

ABSTRACT: IntroductionSpontaneous intracranial hypotension (SIH) due to a spinal CSF leak is associated with substantial health loss. However, SIH is not represented as a distinct condition in the Global Burden of Disease framework, and no disease specific disability weight has been reported. A disability weight is the fundamental basis for comparative analyses of disease burden. The objective of this study was to estimate a patient-derived disability weight for SIH based on pre-treatment health-related quality of life data and to contextualize this estimate relative to published values for other conditions.MethodsWe conducted a retrospective observational study of consecutive patients with confirmed spinal CSF leaks treated at a tertiary referral center between October 2020 and October 2025. Pre-treatment quality of life and headache burden were assessed using the EQ-5D-5L and HIT-6 questionnaires. After calculating the EQ-Index using the German value set, the mean disability weight and its 95% confidence interval were derived using a linear transformation. For contextual interpretation, the newly estimated disability weight was compared descriptively with published values for deliberately selected neurological, headache- or pain-related, and chronic conditions.ResultsA total of 321 patients with confirmed spinal CSF leaks before targeted treatment were included (60.4% female; median age 47 years [IQR 37-56.). Most patients had a ventral leak (192/321, 60%), followed by CSF-venous fistulas (67/321, 21%) and lateral leaks (62/321, 19%). The mean EQ-Index was 0.568 (95% CI 0.533-0.603), the median EQ-VAS was 45.5 (IQR 30-65). The median HIT-6 score was 65 (IQR 59-68). All scores showed no significant differences between the three leak types. Based on EQ-5D-5L data, the resulting mean disability weight for SIH was 0.432 (95% CI 0.40-0.47).ConclusionThis study provides a first patient-derived disability weight estimate of 0.432 for ongoing SIH. This indicates a substantial non-fatal health loss that is comparable to or exceeding that of other chronic conditions. This estimate enables contextual comparison with other conditions and provides a foundation for future burden-of-disease assessments of this curable condition.  

PMID: 42037515
DOI: 10.1177/03331024261444662

AUTHORS: Daniel Liu, Jayasree Oruganti, TsungYen Chen, Frank Feigenbaum 

CITATION: European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, 10.1007/s00586-026-09961-7. 22 Apr. 2026, doi:10.1007/s00586-026-09961-7

PURPOSE: We present a rare case of a giant intrasacral meningocele with a unique presentation, discuss diagnostic challenges, and describe surgical management. Although intrasacral meningoceles are often incidentally found, they can cause debilitating pain and other severe neurological symptoms.

METHODS: A 48-year-old woman initially presented with severe orthostatic headaches, nausea, and vomiting. Cranial and cervical spine imaging was unremarkable, and CSF analysis showed lymphocytic pleocytosis, leading to a diagnosis of aseptic meningitis. Symptoms partially improved with conservative management but recurred 2.5 years later after a fall onto the sacrum, now with sacral pain and left-sided radiculopathy in addition to prior symptoms. Whole-spine MRI revealed a large intrasacral cyst with dural ectasia and possible spinal cord tethering. Surgical intervention included cyst resection, detethering of the spinal cord, closure of the cyst ostium, and reconstruction of the sacrum. Genetic testing for connective tissue disorders was also performed.

RESULTS: The presence of a giant intrasacral meningocele compressing the sacral nerve roots with an associated tethered cord was confirmed intraoperatively. Postoperatively, orthostatic headaches and radiculopathy resolved. Genetic testing identified a variant of uncertain significance in the SKI gene, raising concern for a possible mild connective tissue phenotype.

CONCLUSION: This case highlights the importance of considering spinal meningeal pathology in the differential diagnosis of patients with unexplained orthostatic headaches, even in the presence of CSF pleocytosis. Surgical management of symptomatic intrasacral meningoceles can lead to rapid and sustained improvements in neurological function and quality of life.

PMID: 42020524
DOI: 10.1007/s00586-026-09961-7

AUTHORS: Pranjal Rai, Matthew C Murphy, Jonathan Graff-Radford, Petrice M Cogswell, Yuan Le, Ian T Mark, John J Chen, Benjamin D Elder, Richard L Ehman, John Huston 

CITATION: AJNR. American journal of neuroradiology, ajnr.A9357. 20 Apr. 2026, doi:10.3174/ajnr.A9357

ABSTRACT: Disorders of cerebrospinal fluid (CSF) dynamics, including idiopathic normal pressure hydrocephalus (iNPH), idiopathic intracranial hypertension (IIH), and spontaneous intracranial hypotension (SIH) frequently present clinical and imaging phenotypes that overlap with other disease processes. Although conventional MRI remains central for identifying characteristic morphologic features, many imaging findings have variable sensitivity, particularly across disease stages. As a result, current diagnostic pathways and treatment selection is still often reliant on invasive, snapshot-based physiologic tests. Magnetic resonance elastography (MRE) provides a noninvasive, quantitative approach to probe brain viscoelastic properties reflecting tissue microstructure and mechanical strain. These properties are influenced by intracranial pressure-volume states within the Monro-Kellie constraints, offering a potential “systems-level” biomarker of intracranial compliance and CSF-venous coupling. This review summarizes the technical foundations of brain MRE relevant to radiologists, including the fundamentals and technical aspects of the technique, and the key sources of measurement variability that influence interpretability and reproducibility. It synthesizes the current clinical evidence supporting MRE for diagnosis, phenotyping, and longitudinal treatment assessment across CSF dynamics disorders, with emphasis on practical integration into contemporary imaging workflows and standardized region-of-interest reporting. Finally, we highlight limitations of existing literature and priorities for future research for MRE in this patient population.

PMID: 42009464
DOI: 10.3174/ajnr.A9357

AUTHORS: Bikei Ryu, Timo Krings, Neil V Patel, Jonathan Pace, Emanuele Orru

CITATION: The neuroradiology journal, 19714009261445614. 18 Apr. 2026, doi:10.1177/19714009261445614

ABSTRACT: Treated cerebrospinal fluid-venous fistulas (CVFs) can recur in up to 15% of cases, and they rarely occur at locations remote from the original lesion; the underlying mechanisms remain unclear. We report the case of a male sexagenarian with spontaneous intracranial hypotension (SIH), diffuse spinal nerve root diverticula, and no CVF identified on baseline lateral decubitus CT myelography (CTM). He underwent high-volume epidural and targeted transforaminal blood and fibrin patching with substantial but incomplete symptom relief, followed by transient rebound intracranial hypertension (RIH). Repeat CTM after symptom recurrence demonstrated a new right T5 CVF arising from a remodeled diverticulum and draining into the azygos system. The fistula was successfully treated with transvenous embolization, resulting in sustained clinical and radiological resolution. This case illustrates that in patients with multilevel diverticula, possibly representing connective tissue weakness, post-treatment pressure shifts (including RIH and other causes of episodic cerebrospinal fluid hypertension) may promote the formation or unmasking of CVFs.

PMID: 41999588
PMCID: PMC13091904 (available on 2027-04-18)
DOI: 10.1177/19714009261445614

AUTHORS: Ajay A Madhavan, Edward S Yoon, J Levi Chazen

CITATION: Korean journal of radiology, 10.3348/kjr.2026.0064. 13 Apr. 2026, doi:10.3348/kjr.2026.0064

🔓Open access! Full study available here. 

ABSTRACT: Spontaneous intracranial hypotension is a neurologic condition that is caused by a spinal cerebrospinal fluid (CSF) leak. The resulting CSF hypovolemia can manifest as a variety of clinical symptoms, with orthostatic headache being the most common. Although this disease has been recognized for decades, modern understanding of the types of causative spinal CSF leaks, diagnostic imaging tests to localize these leaks, and treatment options has evolved substantially in recent years. In this focused review article, we will provide an overview of the current diagnosis and treatment of spontaneous intracranial hypotension. We will emphasize recent improvements in understanding the pathophysiology of spinal leaks, developments in myelographic techniques to localize CSF leaks, and new treatment options for each type of leak.

PMID: 41974534  
DOI: 10.3348/kjr.2026.0064

AUTHORS: Wouter I Schievink, Marcel M Maya, Ajay A Madhavan, Franklin G Moser, Miriam A Nuño 

CITATION: AJNR. American journal of neuroradiology, ajnr.A9207. 10 Apr. 2026, doi:10.3174/ajnr.A9207

BACKGROUND AND PURPOSE: Genetic factors often are implicated in the etiology and pathogenesis of spontaneous spinal CSF leaks. Nevertheless, the familial occurrence of spontaneous intracranial hypotension (SIH) and the prevalence of heritable connective tissue disorders (hCTDs) have never been studied in large patient series. The purpose of this study was to determine the frequency of familial SIH and of hCTDs in a large cohort of patients with SIH.

METHODS: In this single-center retrospective observational study, data elements indicating familial SIH and presence of hCTDs were extracted from a prospectively maintained data base. In this data base, the patients’ clinical characteristics, including family history of SIH and diagnosis of hCTD, are abstracted prospectively and updated with each change or addition to the data elements. We studied the time-period between 1/1/2001 and 12/31/2023.

RESULTS: Among 1945 SIH patients, twelve patients (0.62%) from nine different families (0.46%) had a family history of SIH (twelve patients were evaluated in person and six patients were not evaluated in person). There were two affected family members in each family. The 18 affected family members included two men and 16 women (mean age: 44.2 years (range, 21-65 years)). Three patients of two different families with a family history of SIH had been diagnosed with a monogenetic hCTD. Overall, 41 (2.1%) of the 1945 patients had a monogenetic hCTD. Thus, three patients (7.3%) from two families (4.9%) of 41 SIH patients with a monogenetic hCTD had a family history of SIH compared to ten patients (0.53%) from seven families (0.37%) among 1904 SIH patients who did not have a monogenetic hCTD (p=.0015).

CONCLUSIONS: The occurrence of SIH among first-degree family members suggests the importance of genetic factors but is rare and hCTDs are uncommon among the entire SIH population. These findings support the notion that SIH is a multifactorial disorder. Further research is crucial to elucidate genetic and acquired factors in the development of spontaneous spinal CSF leaks. For now, patients can be reassured that the risk of, for example, their offspring developing a spontaneous CSF leak – a commonly voiced concern – is not particularly high.

PMID: 41962957
DOI: 10.3174/ajnr.A9207

AUTHORS: Rayees A. Konduru, Arshiya Shabnam, Joel Yarmush, Hattiangadi Sangeetha Kamath

CITATION: Cureus, vol. 18, no. 4, 6 Apr. 2026, e106499, doi:10.7759/cureus.106499

🔓Open access! Full study available here

ABSTRACT: Post-dural puncture headache (PDPH) is a well-recognized secondary headache disorder resulting from persistent cerebrospinal fluid (CSF) leakage following iatrogenic dural disruption during neuraxial procedures, including spinal anesthesia, diagnostic lumbar puncture, dural puncture epidural (DPE), and unintentional dural puncture (UDP). The syndrome reflects a complex interaction between CSF hydrodynamics, craniospinal compliance, vascular compensation, and nociceptive sensitization. Reduction in CSF volume produces intracranial hypotension and compensatory venous dilation in accordance with the Monro-Kellie doctrine, while loss of CSF buoyancy permits caudal displacement of intracranial structures, resulting in traction on pain-sensitive meninges and cranial nerves and generating the characteristic orthostatic headache. Procedural variables, particularly needle gauge and tip geometry, represent the most important modifiable determinants of PDPH risk. Incidence varies from less than 3% following spinal anesthesia with small-gauge atraumatic needles to 50-85% after UDP with large-bore Tuohy needles, whereas DPE techniques demonstrate comparatively low incidence (approximately 0.5-2%). Management ranges from conservative therapy with hydration, analgesics, and caffeine to targeted pharmacologic therapies and epidural blood patch, which remains the gold-standard intervention with success rates approaching 70-90%. Emerging evidence implicating glymphatic dysfunction, neuroinflammatory mechanisms, and advanced imaging-based leak localization may facilitate improved risk stratification and individualized therapeutic strategies.  

DOI: 10.7759/cureus.106499

*This paper does not have an abstract available, but is available via open access.

AUTHORS: Rayyan Kinsara, Anish Kapadia, Howard Meng 

CITATION: Headache, 10.1111/head.70088. 3 Apr. 2026, doi:10.1111/head.70088

🔓Open access! Full study available here

PMID: 41933923  
DOI: 10.1111/head.70088

AUTHORS: Andrew L Callen, Kyle Jenkins

CITATION: Headache, 10.1111/head.70096. 3 Apr. 2026, doi:10.1111/head.70096

🔓Open access! Full study available here. 

OBJECTIVE: This study was conducted to provide a clinically oriented, mechanism-based framework for interpreting neuroimaging across disorders of cerebrospinal fluid (CSF) pressure, with particular emphasis on patients who fall between classic diagnostic categories of spontaneous intracranial hypotension (SIH) and idiopathic intracranial hypertension (IIH).

BACKGROUND: Headache specialists are increasingly asked to evaluate patients whose symptoms, imaging, and opening pressures do not fit neatly within International Classification of Headache Disorders, 3rd edition criteria. At the same time, modern work in SIH, IIH, CSF-venous fistulas (CVFs) and rebound intracranial hypertension (RIH) has highlighted that these entities are better understood as dynamic expressions of a shared craniospinal physiology rather than isolated syndromes.

METHODS: This narrative review synthesizes contemporary literature on SIH, IIH, CVF, and RIH together with the authors’ experience in a tertiary CSF disorder program. We focus on imaging markers of buoyancy loss and venous adaptation, the Bern score and its extensions, adjunctive MRI features that refine pretest probability when the brain MRI is normal, evolving myelographic techniques including photon-counting computed tomography, modern MRI phenotyping in IIH, and recent data on opening pressures in SIH and CVF. These data are organized around a unifying physiologic model rather than by individual disease labels.

RESULTS: In SIH, the shift from a binary to a probability-based imaging paradigm-anchored by the Bern score-has been complemented by additional markers such as meningeal diverticula, optic nerve sheath narrowing, and imaging findings suggestive of migraine that further inform decisions about advanced myelography even when the brain MRI is formally normal. Recognition of lateral dural tears with small herniated arachnoid pouches mimicking meningeal diverticula and CVFs detectable with only advanced myelographic techniques underscores that absence of a localized leak does not exclude SIH. Most patients with imaging-proven SIH have normal or even elevated opening pressures, challenging current diagnostic criteria and suggesting that some leaks may arise in the setting of chronically increased craniospinal pressure. In IIH, only a subset of MRI features meaningfully discriminates true IIH from mimics, and venous sinus behavior emerges as a dynamic marker of compliance rather than a simple anatomic lesion. RIH after leak closure and “popping the balloon” in patients with established IIH who develop spinal leaks both illustrate how modest shifts in CSF volume and venous capacitance can drive rapid transitions between high- and low-pressure states.

CONCLUSION: Disorders of CSF pressure are best conceptualized as points along an interconnected physiologic continuum in which buoyancy, venous compliance, leak morphology, and CSF-venous communication interact to produce the observed clinical and imaging phenotypes. For patients with mixed or subtle findings, applying this mechanism-oriented framework can improve interpretation of MRI and myelography, prevent premature exclusion of SIH or IIH on the basis of normal opening pressure or “negative” imaging, and support more nuanced, individualized treatment decisions in clinical practice.

PMID: 41933933
DOI: 10.1111/head.70096

AUTHORS: Wouter I Schievink, Marcel M Maya, Franklin G Moser, Vikram Wadhwa, Ravi S Prasad 

CITATION: AJNR. American journal of neuroradiology vol. 47,4 1141-1146. 2 Apr. 2026, doi:10.3174/ajnr.A9085

BACKGROUND AND PURPOSE: Some patients with spontaneous intracranial hypotension (SIH) continue to have symptoms despite radiographic resolution of their spinal CSF leak. The purpose of the present study is to report the indications, intraoperative findings, and outcomes of exploratory surgery of radiographically resolved spontaneous ventral spinal CSF leaks.

MATERIALS AND METHODS: A single-center review was performed of a prospectively maintained database to identify a consecutive group of patients who underwent surgical exploration of radiographically resolved spontaneous ventral spinal CSF leaks. Patients completed a spontaneous intracranial hypotension disability assessment score (SIHDAS) pre- and postoperatively.

RESULTS: Eight patients (4 men and 4 women) were identified. The mean age was 45.9 years (range, 31-61 years). Radiographic resolution of the extradural CSF collection occurred spontaneously in 2 patients and followed epidural blood or fibrin glue patching in 6 patients. The mean duration of SIH symptoms at the time of surgical exploration was 24 months (range 5 months to 6 years). The most common site for exploration was at T1-T2. At surgery, we were able to identify the healed dural defect in 7 patients and these were repaired with sutures or a muscle plug. Postoperatively, 6 patients reported complete or near-complete symptom resolution with SIHDAS scores improving from moderate or severe disability to little or no or mild disability.

CONCLUSIONS: In highly selected patients, surgical exploration of radiographically resolved spontaneous ventral spinal CSF leaks may be considered in patients with persistent symptoms of SIH. The target of surgical exploration is the most suspicious causative calcific lesion or is based on prior imaging showing the exact site of the CSF leak.

PMID: 41927342
PMCID: PMC13045890 (available on 2027-04-01)
DOI: 10.3174/ajnr.A9085

AUTHORS: Catherine M Garcia, Daniel Chang, Marcel M Maya, Vikram S Wadhwa, Ravi S Prasad, Franklin G Moser, Wouter I Schievink 

CITATION: AJNR. American journal of neuroradiology vol. 47,4 1135-1140. 2 Apr. 2026, doi:10.3174/ajnr.A9091

BACKGROUND AND PURPOSE: Intracranial hypotension-arising from CSF leaks that are iatrogenic, traumatic, or spontaneous-is a potentially debilitating condition resulting in orthostatic headaches and other neurologic symptoms. While pediatric CSF leaks are challenging to manage due to limited data, digital subtraction myelography (DSM) has shown promise as a highly sensitive diagnostic tool for visualizing these leaks. This study reviews the use of DSM in pediatric patients for diagnosing and localizing CSF leaks at a quaternary center for intracranial hypotension.

MATERIALS AND METHODS: Using prospective registries, we analyzed pediatric patients (19 years of age or younger) evaluated for CSF leaks at our institution between 2001 and 2025. Patients underwent DSM under standardized protocols, including adjustments for positioning based on suspected leak locations. Data on demographics, clinical presentation, imaging findings, and outcomes were also analyzed.

RESULTS: Forty-one patients (27 females, 14 males; mean age, 15.69 [SD, 3.12] years) underwent 73 DSMs. The average fluoroscopy time was 1.8 (SD 1.4) minutes, and the mean kinetic energy released per unit mass (air kerma) radiation dose was 324.8 (SD, 373.8) mGy. No complications were reported. Among 28 patients with suspected spontaneous intracranial hypotension (SIH), 54 DSMs were performed; orthostatic headache was the presenting symptom in 96.4%. Eighteen leaks were identified in 16 patients (57.1%), most commonly type 1b (33.3%) and type 3 (27.8%) leaks. Of 15 patients undergoing surgery, intraoperative findings confirmed DSM results in 14 cases. Thirteen patients with traumatic or iatrogenic leaks underwent 19 DSMs; orthostatic headache was present in 92.3%. Eight leaks were identified in 6 patients (46.2%), predominantly ventral, and all underwent directed interventions.

CONCLUSIONS: DSM is a safe and effective diagnostic technique for pediatric CSF leaks, enabling precise localization critical for targeted treatment. Incorporating DSM into the diagnostic workflow may improve outcomes for children with intracranial hypotension, but further multicenter studies are needed to validate findings and optimize protocols.

PMID: 41927334  
PMCID: PMC13045906 (available on 2027-04-01)  
DOI: 10.3174/ajnr.A9091

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

CITATION: American journal of neuroradiologyvol. 47,4 1155-1158. 2 Apr. 2026, doi:10.3174/ajnr.A9038

ABSTRACT: A subset of postdural puncture headaches (PDPH) persist despite conventional epidural blood patches (EPDs), leading to chronic symptoms and substantial disability. Dural punctures may involve not only the dorsal dural surface, which is covered by a standard interlaminar 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 6 patients with PDPH, 4 of whom had failed prior dorsal-only EBPs. Intraprocedural imaging confirmed complete circumferential patch coverage in all cases, and all 6 patients reported substantial or complete symptomatic resolution. These results establish the feasibility of CT fluoroscopy-guided circumferential EBP for PDPH.

PMID: 41073140
PMCID: PMC13045901 (available on 2027-04-01)
DOI: 10.3174/ajnr.A9038

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

CITATION: AJNR. American journal of neuroradiology, ajnr.A9327. 31 Mar. 2026, doi:10.3174/ajnr.A9327

BACKGROUND AND PURPOSE: Cerebrospinal fluid-venous fistulas (CVF) cause spontaneous intracranial hypotension (SIH) and can be treated with transvenous embolization (TVE). Although TVE has been shown to result in substantial symptomatic improvement, some patients may require retreatment. The purpose of this study was to clarify the rate, anatomical location, and timing of CVF recurrence/retreatment after TVE.

MATERIALS AND METHODS: Single center, retrospective cohort of consecutive patients with CVF who were treated with TVE. The rate of retreatment after TVE was determined. In addition, timing of symptom onset and location of recurrent CVF was recorded.

RESULTS: One hundred consecutive patients (65% female, mean age 59.3 years) with 105 CVFs treated with TVE were included. Overall, 23% (23/100) of patients required retreatment due to persistence or recurrence of symptoms. Most retreatment patients (74%, 17/23) had persistent or recurrent symptoms within 3 months after TVE. Approximately one third of patients needing retreatment (35%, 8/23) had a CVF at the same site and level as the initial CVF after having been embolized. Approximately one third (30%, 7/23) had a recurrent CVF adjacent to the initial CVF (defined as one level above, one level below, or at the same level but on the contralateral side). The remaining patients (35%, 8/23) had a CVF remote from the original fistula site.

CONCLUSIONS: Approximately 23% of patients with CVF that are treated with TVE will require retreatment. Symptom recurrence is most common within 3 months after initial treatment. Recurrence can occur due to local treatment failure or development of collateral drainage pathways, but a substantial proportion of patients develop de novo CVFs remote from the initial treatment site. These findings can be used to counsel patients and to manage treatment expectations.

PMID: 41916752  
DOI: 10.3174/ajnr.A9327

AUTHORS: W Elorm Yevudza Jnr, Gayle Salama, John K Park 

CITATION: World neurosurgery, 124943. 30 Mar. 2026, doi:10.1016/j.wneu.2026.124943

ABSTRACT: Spontaneous spinal cerebrospinal fluid (CSF) leaks are a major cause of spontaneous intracranial hypotension. Minimally invasive surgical (MIS) approaches have been developed to reduce perioperative morbidity while preserving repair durability, yet their comparative effectiveness remains incompletely defined. We performed a systematic review and meta-analysis of contemporary surgical series following PRISMA 2020 guidelines. Twenty studies met criteria for qualitative synthesis; nine contributed to the quantitative synthesis. Primary closure success was 95% (95% CI 88.8-97.8; I2 = 0%), and recurrence or reoperation occurred in 10% (95% CI 5.9-15.8; I2 = 0%). Subgroup analysis showed numerically similar rates between MIS and open repair in both closure (97% vs 92%; p > 0.05) and recurrence (10% vs 9%; p = 0.86), though formal non-inferiority testing was not appropriate because the available evidence consisted predominantly of nonrandomized retrospective cohorts without a prespecified non-inferiority margin or direct adjusted between-group comparisons. Complete symptom resolution was 71% in open cohorts (I2 = 87%); MIS cohorts lacked consistent denominators for quantitative pooling. Some cohorts reported shorter length of stay and reduced postoperative pain in MIS groups, but these between-study comparisons were descriptive and confounded by case selection. However, the observational nature of the data, absence of randomization, and unmeasured selection bias-whereby more complex leaks may have been preferentially treated with open surgery-preclude definitive comparative conclusions. In selected cases, MIS dural repair may approach the success rates of open procedures with comparable complication profiles, but prospective studies controlling for selection bias are needed.

PMID: 41921778
DOI: 10.1016/j.wneu.2026.124943

AUTHORS: Emanuele Orru, Bikei Ryu, Timo Krings, Jonathan Pace, Neil V Patel

CITATION: Journal of neurointerventional surgery, jnis-2026-025082. 27 Mar. 2026, doi:10.1136/jnis-2026-025082

BACKGROUND AND PURPOSE: Transvenous embolization for cerebrospinal fluid–venous fistula (CVF)-related spontaneous intracranial hypotension is increasingly performed, yet procedure-level dosimetry and specific benchmarks are undefined. We quantified radiation exposure during CVF embolization, identified determinants of higher dose, and derived local reference levels using diagnostic-reference-level (DRL) methodology.

METHODS: This retrospective study analyzed a single center cohort of consecutive CVF embolizations (May 2023–September 2025). Studied dose indices were kerma–area product (KAP, Gy·cm²) and reference air kerma (Ka,r, Gy), partitioned by acquisition mode and plane. Associations with patient/procedural variables (body mass index (BMI), number of levels, navigation time, Onyx injection time, fluoroscopy time, plane use, cone-beam CT (CBCT)) were evaluated using non-parametric tests and Spearman correlations. DRLs were defined as the 75th percentile. Radiation-attributable skin effects were assessed at follow-up when indicated.

RESULTS: 52 embolizations were performed in 43 patients. Median KAP was 288.3 Gy·cm² and median Ka,r 3.29 Gy. For all procedures, DRLs were KAP 515.7 Gy·cm² and Ka,r 4.76 Gy; for single-level cases, Ka,r 3.23 Gy. Ka,r >3 Gy occurred in 28/52 (53.8%) procedures. Dose accrued predominantly on the lateral plane and increased with higher BMI, more embolized levels, and longer navigation/injection times. CBCT use was not associated with higher dose. No radiation-attributable skin injury was documented on follow-up.

CONCLUSIONS: Transvenous CVF embolization frequently incurs significant radiation exposure, mostly driven by lateral plane utilization and procedural complexity. We propose practical adjustments—limiting lateral plane utilization, digital zoom, and staging multilevel cases—that can plausibly reduce exposure.

PMID: 41895848
DOI: 10.1136/jnis-2026-025082

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

CITATION: AJNR. American journal of neuroradiology, ajnr.A9308. 25 Mar. 2026, doi:10.3174/ajnr.A9308

BACKGROUND AND PURPOSE: Photon-counting detector CT (PCD-CT) offers improved spatial resolution compared with conventional energy-integrating detector CT (EID-CT), but session-level dose comparisons in multi-acquisition CT myelography (CTM) are limited. We compared radiation dose between PCD-CTM and EID-CTM for detecting CSF-venous fistulas (CVFs) in patients with spontaneous intracranial hypotension (SIH).

MATERIALS AND METHODS: This retrospective, single-center cohort study included 603 CTM examinations (EID-CTM, n=470; PCD-CTM, n=133) performed for SIH evaluation between 2020 and 2025. The primary endpoint was session dose-length product (DLP) for the entire CTM examination. Secondary endpoints included diagnostic-series CTDIvol and DLP in CVF-positive examinations (Duke CSF-Venous Fistula Confidence Score ≥2) and a scan length proxy (diagnostic DLP/CTDIvol). Radiation dose metrics were compared using nonparametric tests and reported as median (IQR).

RESULTS: Session DLP was significantly lower for PCD-CTM than for EID-CTM: 1760 (1277-2206) vs 5030 (3476-6559) mGy·cm (median reduction, 65.0%; P < .001). In CVF-positive examinations, PCD-CTM demonstrated significantly lower diagnostic-series CTDIvol (median reduction, 79.9%; P < .001) and diagnostic-series DLP (median reduction, 74.1%; P < .001). These reductions persisted despite PCD-CTM covering a significantly longer scan length (P < .001) and acquiring more series per examination (P < .001).

CONCLUSIONS: In patients undergoing CT myelography for CVF evaluation, PCD-CTM was associated with an approximately 65% lower session-level radiation dose than EID-CTM, despite covering a longer anatomic range and more acquisitions.

PMID: 41881568
DOI: 10.3174/ajnr.A9308

AUTHORS: Ajay A Madhavan, Peter G Kranz, Michelle L Kodet, E Hope Weant, Michael D Malinzak, Jay Willhite, Linda Gray, Timothy J Amrhein

CITATION: AJNR. American journal of neuroradiology, ajnr.A9309. 25 Mar. 2026, doi:10.3174/ajnr.A9309

BACKGROUND AND PURPOSE: Dural tears are a major cause of spontaneous intracranial hypotension. The existence of a dural tear can be inferred by the presence of extradural CSF on spine MRI. However, extradural CSF usually spans multiple spinal levels, precluding localization of the dural tear on MRI. The C1-C2 false localizing sign (C1-C2 sign) refers to preferential pooling of extradural CSF dorsally at C1-C2, even though this is typically not the site of leak. While this has been described as an important false localizing sign, other potentially important features of this imaging finding have not been studied. Here, we sought to estimate the prevalence of the C1-C2 sign in patients with spontaneous dural tears and determine whether presence of the C1-C2 sign correlates with length of disease.

MATERIALS AND METHODS: We retrospectively identified all patients diagnosed with a dural tear on dynamic CT myelography at our institution between January 2024 and January 2026. We excluded patients who did not have SIH or lacked pre-myelographic spine MRI with T2-weighted fat suppressed sequences. For patients in the final cohort, we recorded the time between symptom onset and initial spine MRI. The presence or absence of the C1-C2 sign on spine MRI was assessed by two neuroradiologists, with any disagreements adjudicated by a third neuroradiologist. The prevalence of the C1-C2 sign was calculated, and correlation with length of symptoms prior to MRI was determined using logistic regression.

RESULTS: Our final cohort consisted of 50 consecutive patients with ventral or lateral dural tears localized on dynamic CT myelography. The C1-C2 sign was present in 23/50 (46%) patients. There was a statistically significant negative correlation between symptom duration prior to MRI and presence of the C1-C2 sign (p < 0.05). Furthermore, we identified 11 patients who underwent two spine MRIs prior to myelography. In 6/11 patients, the C1-C2 sign was initially present and resolved over time.

CONCLUSIONS: The C1-C2 false localizing sign is associated with a relatively shorter disease duration. Its presence may be helpful in determining optimal treatment strategies in patients with dural tears.

PMID: 41881567
DOI: 10.3174/ajnr.A9309

AUTHORS: Andrew L Callen, Daniel Montes, Timothy J Amrhein, Jürgen Beck, Enrique Barvulsky, Debayan Bhaumik, Andre E Boyke, Federico Cagnazzo, Lalani Carlton Jones, Tomas Dobrocky, Peter G Kranz, Peter Lennarson, Ajay Madhavan, Mark D Mamlouk, Ian T Mark, Marcel Maya, Eike I Piechowiak, Wouter Schievink, Florian Volz, Katharina Wolf, Horst Urbach, Niklas Lützen

CITATION: AJNR. American journal of neuroradiology, ajnr.A9297. 16 Mar. 2026, doi:10.3174/ajnr.A9297

BACKGROUND AND PURPOSE: Sacral dural tears are an underrecognized cause of spontaneous intracranial hypotension, and their clinical behavior and response to treatment remain incompletely defined. We hypothesized that outcomes following epidural patching in sacral dural tears are driven primarily by disease chronicity and baseline imaging features, mirroring patterns observed in other SIH leak subtypes, and are less dependent on procedural variables.

MATERIALS AND METHODS: We performed a multicenter retrospective cohort study of patients with SIH attributed to sacral dural tears who underwent epidural patching and had clinical and/or imaging follow-up. Of 61 identified patients, 54 met inclusion criteria. Clinical outcomes, brain and spine imaging findings, and procedural variables were analyzed. Univariate and multivariable logistic regression models were used to identify predictors of clinical and imaging outcomes. Myelographic techniques were compared for rates of precise leak localization.

RESULTS: The mean age was 37.8 years, and 85% of patients were women. Complete clinical improvement following patching occurred in 28 of 50 patients (56%), and complete resolution of sacral extradural CSF on follow-up spine MRI occurred in 17 of 37 patients (46%). Greater improvement in Bern score was independently associated with complete clinical improvement (OR 0.73, 95% CI 0.54-0.99, p = 0.04) and showed a pattern toward imaging resolution. Unorganized baseline extradural CSF morphology predicted better clinical (p = 0.03) and imaging (p = 0.03) outcomes. Procedural variables, including injectate type, volume, and needle approach were not associated with outcome. Dynamic CT myelography precisely localized the leak more frequently than digital subtraction myelography (75% vs 31%, p = 0.02). Eight patients underwent surgery, with mixed clinical and imaging outcomes.

CONCLUSIONS: Epidural patching outcomes in sacral dural tears causing SIH are driven primarily by baseline imaging phenotype, disease stage, and intracranial imaging response rather than procedural technique. These findings support a morphology- and chronicity-aware approach to diagnosis and treatment and suggest that sacral dural tears represent a distinct SIH subtype with outcome patterns similar to other leak mechanisms.

PMID: 41839613
DOI: 10.3174/ajnr.A9297

AUTHORS: James Evans, Julia Lowin, Pippa Anderson 

CITATION: Cost effectiveness and resource allocation : C/E, 10.1186/s12962-025-00612-0. 6 Mar. 2026, doi:10.1186/s12962-025-00612-0

🔓Open access! Full study available here. 

INTRODUCTION: Clinical evidence indicates that atraumatic needles (ATNs) versus conventional needles (CNs) reduce diagnostic lumbar puncture (DLP) complications. Despite this, the use of CNs in DLP remains widespread. This analysis estimates the cost-effectiveness of ATNs versus CNs in DLP.

METHODS: We constructed a model mapping DLP patient pathways and complications (limited to PDPH events and PDPH-related hospitalisations/epidural blood patches (EBP)). Model development was carried out in consultation with local clinical experts. Published data informed clinical data inputs (DLP characteristics and likelihood of PDPH) and resource estimates. Costs of PDPH management were estimated from UK NHS Reference Costs. Costs of LP were limited to needle costs. Model outputs included total PDPH, total costs, cost per PDPH avoided and numbers need to treat (NNT) to avoid one case of PDPH. Extensive one-way sensitivity analyses were conducted.

RESULTS: Based on 100 patients undergoing DLP with CN (ATN), we estimated 31 (12) cases of PDPH with 7 (3) patients requiring EBP with total costs estimated at £9,469 (£4,257) i.e. 19 fewer cases of PDPH with ATN at a cost saving of £5,212. NNT to avoid one case of PDPH (hospitalised PDPH) was estimated at 5 (13). Clinical benefits and cost savings were robust to plausible input changes.

DISCUSSION AND CONCLUSION: Our model findings support an economic case for use of ATN in preference to CN in DLP, with improved outcomes achieved at a cost saving. Local data collection is recommended but is not expected to change the model findings.

PMID: 41792808
DOI: 10.1186/s12962-025-00612-0

AUTHORS: Charlotte Zander, Alexander Rau, Niklas Lützen, Katharina Wolf, Florian Volz, Amir El Rahal, Laura Krismer, Hansjörg Mast, Marco Reisert, Elias Kellner, Jürgen Beck, Horst Urbach, Theo Demerath 

CITATION :Fluids and barriers of the CNS, 10.1186/s12987-026-00785-7. 3 Mar. 2026, doi:10.1186/s12987-026-00785-7

🔓Open access! Full study available here. 

BACKGROUND: CSF loss in spontaneous intracranial hypotension (SIH) has been related to alterations in glymphatic flow, which is poorly understood in this disease. Advanced multi-shell diffusion-weighted MRI (dMRI) enables quantification of the interstitial free water fraction, serving as a possible surrogate marker for glymphatic system function in patients with SIH.

METHODS: SIH Patients underwent dMRI before and after closure of a spinal CSF leak. The microstructural free water compartment (V-CSF) of the whole brain gray and white matter, corona radiata, amygdala, hippocampi and parahippocampal gyri was compared to 23 age-matched normal controls. Pre- and post-therapeutic volumetry encompassed the total ventricular, total gray and white matter compartments and mesial temporal structures.

RESULTS: 23 SIH patients (50.3 ± 13.1 years, 15 women) were included. After leak closure, V-CSF increased in the global gray matter (mean pre 0.140 vs. mean post 0.151; p = 0.029), posterior corona radiata (mean pre 0.103 vs. mean post 0.108; p = 0.0055), hippocampi (mean pre 0.100 vs. mean post 0.105; p = 0.001), and parahippocampal gyri (mean pre 0.156 vs. mean post 0.177; p = 0.009). Compared to normal controls, V-CSF was decreased before leak closure in the hippocampi (mean pre 0.100 vs. mean NC 0.211; p = 0.0019) and posterior corona radiata (mean pre 0.103 vs. mean NC 0.118; p = 0.011). No significant change of total gray or white matter volume occurred after leak closure.

CONCLUSION: Closure of the spinal CSF leak leads to an increase of interstitial fluid in gray matter, corona radiata, hippocampi, and parahippocampal gyri, respectively. Our results suggest, that SIH patients may have less interstitial fluid in the hippocampi and posterior corona radiata compared to normal controls. Whether shifts in brain interstitial fluid in eloquent cerebral regions contribute to cognitive decline in patients with CSF loss should be topic of further research.

PMID: 41776643
DOI: 10.1186/s12987-026-00785-7

AUTHORS: Zaid Saadeh, Sherief A Ghozy, Esref A Bayraktar, Waleed Brinjikji, Ajay A Madhavan, John C Benson, Jared T Verdoorn, Parnian Habibi, Jeremy K Cutsforth-Gregory, Ian T Mark 

CITATION: AJNR. American journal of neuroradiology, ajnr.A9187. 2 Mar. 2026, doi:10.3174/ajnr.A9187

BACKGROUND AND PURPOSE: CSF-venous fistulas (CVFs) are an important and underrecognized cause of spontaneous intracranial hypotension. They are direct communications between the subarachnoid space and paraspinal vein resulting in loss of CSF. We performed a systematic review and meta-analysis to evaluate the prevalence of affected laterality or spinal levels.

METHODS AND MATERIALS: A literature review identified 587 studies for possible inclusion and 43 were selected as relevant by two screeners. Studies from the same institution with data overlap and <3 subjects were removed. Demographic characteristics, side of involvement and spinal levels of CVFs were collected when available and included in the analysis. Pooled prevalence rates were computed, and age and gender distribution across studies were analyzed. Pairwise meta-regression was used, and laterality was further assessed at each spinal level to determine the distribution of right- versus left-sided leaks. Statistical significance was defined as p < 0.05.

RESULTS: CVFs were most common on the right compared to other patterns such as left-sidedness and bilaterally (67% CI: 0.62-0.73; p <0.001). Nearly all were in the thoracic spine (96% CI: 0.93-0.98). T7 and T9 demonstrated the highest prevalence rate for specific spinal levels out of the analyzed CVFs at 19% each. T10 also showed high prevalence rate of 17%. The lumbar and cervical spine demonstrated significantly lower prevalence when compared to the thoracic region (P<0.001). Descriptive analysis of the CVFs by spinal level and laterality demonstrated that the major leak sites were right T7 (7.8%), T6 (6%), and T10 (5.5%).

CONCLUSIONS: Localization of CVFs is crucial in therapeutic planning and intervention. We found significantly more on the right utilizing the available literature for analysis. The greatest prevalence rates by level were in the lower thoracic spine at T7, T9, and T10. One possible etiology for this pattern could be the azygous vein and an abundance of arachnoid granulations at these levels.

PMID: 41771733
DOI: 10.3174/ajnr.A9187

AUTHORS: Eike I Piechowiak, Fabio Pisi, Thomas Petutschnigg, Jan Gralla, Johannes Kaesmacher, Ralph T Schär, Andreas Raabe, Levin Häni, Johannes Goldberg, Jean-Benoît Rossel, Katharina Wolf, Jürgen Beck, C Marvin Jesse, Tomas Dobrocky

CITATION: AJNR. American journal of neuroradiology, 10.3174/ajnr.A9055. 26 Feb. 2026, doi:10.3174/ajnr.A9055

🔓Open access! Full study available here. 

BACKGROUND AND PURPOSE: Spontaneous intracranial hypotension (SIH) is caused by CSF leakage at the spinal level, resulting in craniospinal CSF depletion and often debilitating symptoms. While changes in intracranial CSF volume in SIH, particularly early depletion and normalization after treatment, are documented, reports of spinal CSF volumetry remain scarce. This study aimed to quantify intrathecal spinal CSF volume in patients with SIH before and after definitive leak closure and compare it with that in a non-SIH control cohort.

MATERIALS AND METHODS: This retrospective, single-center study included 35 patients with SIH with confirmed spinal CSF leaks (types 1-3) and 10 non-SIH controls. All patients with SIH underwent surgical or endovascular leak closure and had high-quality pre- and posttreatment isotropic 3D T2-weighted MR imaging. Spinal intrathecal CSF volume was measured using semi-automated segmentation, excluding spinal longitudinal epidural fluid collections (SLEC), if present. Paired and unpaired statistical tests were applied.

RESULTS: In total 18, SLEC-positive (+) and 17 SLEC-negative (-) patients and 10 non-SIH controls were evaluated. After successful leak closure, spinal CSF volume increased significantly in patients with SIH (+13%, P < .001). This increase was seen in both SLEC+ (+18%, P < .001) and SLEC- (+5%, P = .02) subgroups. No significant difference was observed between patients with SIH pretreatment and controls. However, posttreatment volumes in patients with SIH were significantly higher than those in controls (+13%, P = .04).

CONCLUSIONS: Spinal CSF volumetry reliably detects a significant increase in intrathecal CSF volume following definitive leak closure in patients with SIH. Notably, posttreatment spinal CSF volumes exceeded those of non-SIH controls, suggesting a potential compensatory mechanism with overshooting CSF volume after prolonged CSF depletion.

PMID: 41748435
DOI: 10.3174/ajnr.A9055

AUTHORS: Wouter I Schievink, Marcel M Maya, Rachelle B Taché, Ravi S Prasad, Vikram Wadhwa, Franklin G Moser

CITATION: AJNR. American journal of neuroradiology, ajnr.A9258. 23 Feb. 2026, doi:10.3174/ajnr.A9258

BACKGROUND AND PURPOSE: Spinal CSF-venous fistulas are an important cause of spontaneous intracranial hypotension (SIH). Most of these fistulas are associated with a meningeal diverticulum, but they arise from the largest diverticulum in only about one-third of cases. De novo recurrent CSF-venous fistulas are defined as a CSF-venous fistula at a different spinal level (or side) following treatment of the initial CSF-venous fistula. Such de novo recurrent fistulas offer a unique opportunity to study the growth of diverticula prior to the development of a fistula.

METHODS: In this single-center retrospective observational study, data elements indicating a de novo recurrent fistula were extracted from a prospectively maintained data base. Using this registry, we identified a consecutive group of patients with de novo recurrent fistulas.

RESULTS: The study population consisted of nine women and six men (mean age: 57.9 years) with SIH and a de novo recurrent fistula. All patients had multiple diverticula, ranging from three to 35 diverticula per patient (total: 215 diverticula). The initial fistula was treated with microsurgical clip ligation in all patients. The mean interval between initial fistula treatment and de novo recurrent fistula formation was two years and four months (range, five months to six years and six months). A change in diverticular size (mean, 2 mm; range: 1 to 3 mm) associated with the de novo recurrent fistula was observed in five (33.3%) of the 15 patients. Diverticular size had increased in three patients and decreased in two patients. No change in size was observed in the other 195 meningeal diverticula.

CONCLUSIONS: We found that in one-third of patients a change in diverticular size was observed corresponding to the site of the de novo recurrent fistula. An increase in diverticular size could be explained by increased diverticular wall tension (law of LaPlace) and attenuation of the diverticular wall resulting in a higher likelihood of developing a CSF-venous fistula and a decrease in size could be explained by decompression of the diverticulum through the fistula. A change in size of meningeal diverticula may help guide the invasive myelographic studies necessary to locate CSF-venous fistulas.

PMID: 41730631
DOI: 10.3174/ajnr.A9258

AUTHORS: Fatma Merzou, Anna-Lena Kunzmann, Daniel Janitschke, Jose Valdueza, Benjamin Landau, Sebastian Roemer, Erwin Stolz, Laurin Schappe, Viviana Versace, Steffen Kottackal, Piergiorgio Lochner

CITATION: Scientific reports, 10.1038/s41598-026-40311-1. 20 Feb. 2026, doi:10.1038/s41598-026-40311-1

🔓Open access! Full study available here. 

ABSTRACT: The aim of our study is to test the hypothesis whether ultrasonographically measured ultrasound-guided optic nerve sheath diameter (US-ONSD) decreases after lumbar puncture (LP) and whether decreased optic nerve sheath diameter (ONSD) after lumbar puncture is associated with headache. The latter might help to identify patients with postdural puncture headache (PDPH). In this prospective observational study 76 patients, who had undergone diagnostic LP using an atraumatic technique, received a measurement of ONSD before (T0), immediately after (T1) and 24 h after LP (T2). Additionally demographic data such as age, sex, body mass index (BMI), and also headaches and symptoms were recorded. In six out of 7 patients with constant PDPH, we additionally measured ONSD 48 h (T3) and 72 h (T4) after LP. All patients (n = 76, 100%) showed a physiological reduction in ONSD at T1. Patients with consistent symptoms of PDPH (n = 7, 9%) kept values below pre-LP levels after 24 and 48 h. No statistical difference was found in BMI, sex, cerebrospinal fluid volume, needle size, or previous headaches between the PDPH (n = 7, 9%) and non-PDPH patients (n = 69, 91%). Younger patients were more likely to experience PDPH symptoms. Since at T2 the ONSD was only reduced in PDPH patients, a significant difference in ONSD was found between PDPH and non-PDPH patients. The cut-off value of ONSD for predicting PDPH at T2 was 4.9 mm in the receiver operating characteristic (ROC) curve (sensitivity 86%, specificity 93%). We were able to demonstrate a physiologic change in ONSD after LP in all patients. The sonographic measurement of ONSD in patients with headache can help to identify and monitor PDPH after LP.

PMID: 41720848
DOI: 10.1038/s41598-026-40311-1

AUTHORS: Eric Esposito, Shenghua Zhu, Edwin Owolo, Gabriel N Friedman, Elie Massaad, Kathleen M Lavoie, Theresa Williamson, Jean Valery Coumans, Lawrence F Borges, Neel Madan, Bart K Chwalisz, Aaron Paul, Ganesh M Shankar

CITATION:Journal of neurosurgery. Case lessonsvol. 11,7 CASE25819. 16 Feb. 2026, doi:10.3171/CASE25819

🔓Open access! Full study available here. 

BACKGROUND: Spontaneous intracranial hypotension (SIH) may result in positional headaches, tinnitus, vestibular symptoms, and cognitive dysfunction. Pachymeningeal enhancement may be seen on contrast-enhancing imaging. Notably, the time course of pachymeningeal enhancement resolution has previously been shown to resolve within 17 hours of surgical repair. The authors sought to determine whether radiographic stigmata of SIH could be used as a marker for effective treatment.

OBSERVATIONS: A retrospective review of 14 patients who underwent open surgical management for SIH was conducted. Clinical notes and pre-and postoperative images were used to determine resolution of pachymeningeal enhancement. All patients experienced resolution of preoperative positional headaches on initial follow-up, with a median of 12 days following surgery. Diffuse pachymeningeal enhancement was found on preoperative MRI brain in all patients, with postoperative imaging showing resolution of pachymeningeal enhancement, with a median of 2 days postsurgery.

LESSONS: Diffuse pachymeningeal enhancement is a reliable marker for resolution SIH and often predates clinical resolution. Therefore, the authors propose that assessing for this characteristic with contrasted-brain MRI may assist in the posttreatment evaluation of patients with SIH.

PMID: 41698188
PMCID: PMC12908245
DOI: 10.3171/CASE25819

AUTHORS: Ajay A Madhavan, Michelle L Kodet, Marcel M Maya, Wouter I Schievink, Thien Huynh 

CITATION: AJNR. American journal of neuroradiology, 10.3174/ajnr.A9058. 12 Feb. 2026, doi:10.3174/ajnr.A9058

ABSTRACT: CSF-venous fistulas are a common cause of spontaneous intracranial hypotension. Most CSF-venous fistulas occur in the thoracic spine, and recently described myelographic techniques have been primarily tailored to localize fistulas in this location. However, a small subset of CSF-venous fistulas can occur at the superior or inferior ends of the spine, ranging from the skull base to the sacrum. In this Video Article, we discuss modifications to decubitus myelography needed to safely and confidently diagnose CSF-venous fistulas at the extremes of the spine, including the skull base and sacrum. We also show unique case examples of these relatively uncommon leaks, which were found using decubitus digital subtraction or CT myelography with simple technical modifications.

PMID: 41679905
DOI: 10.3174/ajnr.A9058

AUTHORS: Parnian Habibi, Andrew Callen, Jared Verdoorn, John Benson, Ajay A Madhavan, Sara Salehi, Jeremy Cutsforth-Gregory, Ian T Mark

CITATION: AJNR. American journal of neuroradiology, ajnr.A9209. 7 Feb. 2026, doi:10.3174/ajnr.A9209

ABSTRACT: Spontaneous intracranial hypotension (SIH) is a debilitating and often misdiagnosed condition. One important differential diagnosis is Chiari malformation type 1 (CM-1), which differs markedly in its pathophysiology, clinical manifestation, and treatment. We report seven cases of SIH initially misdiagnosed as CM-1, emphasizing the importance of considering SIH when evaluating low-lying cerebellar tonsils to prevent unnecessary procedures and delays in appropriate treatment.

PMID: 41654330 
DOI: 10.3174/ajnr.A9209

AUTHORS: Alexandre Bani-Sadr, Apolline Guérin, Caroline Froment Tilikete, Geneviève Demarquay, Virginie Desestret, Yves Berthezène, Mark D Mamlouk 

CITATION: AJNR. American journal of neuroradiology, ajnr.A9216. 7 Feb. 2026, doi:10.3174/ajnr.A9216

ABSTRACT: We evaluated the safety and efficacy of CT-guided intracystic fibrin glue injection for cerebrospinal fluid-venous fistulas (CVFs) causing spontaneous intracranial hypotension. In this 2-center retrospective series, 16 patients underwent fibrin injection directly into the diverticular cyst, with additional epidural or paravertebral injection as needed. Median intracystic fibrin volume was 1.0 mL; thecal sac extension was present in 44% of cases. No serious or permanent complications, arachnoiditis, or neurologic deficits were observed. Transient rebound intracranial hypertension occurred in 31% and transient radicular pain in 6%, both resolving spontaneously. Clinical outcomes were favorable, with 88% of patients reporting complete and 12% partial symptom improvement. The median Bern score decreased from 6.0 pretreatment to 0 posttreatment, and CT myelography in a subset confirmed fistula closure. CT-guided intracystic fibrin glue injection appears to be a safe, effective, and targeted option for CVF treatment, meriting further prospective evaluation.  

PMID: 41654329
DOI: 10.3174/ajnr.A9216

AUTHORS: Kaissar Sassi, Rachel Fresquet, Marie-Lucie Dubois, Vincent Minville, Thomas Geeraerts 

CITATION: Journal of clinical monitoring and computing, 10.1007/s10877-025-01395-8. 5 Feb. 2026, doi:10.1007/s10877-025-01395-8

🔓Open access! Full study available here. 

ABSTRACT: Post-dural puncture headache (PDPH) following epidural anesthesia remains a frequent obstetric complication. While epidural blood patch (EBP) is the reference treatment, its efficacy assessment still relies on subjective pain reporting. This study explored whether changes in optic nerve sheath diameter (ONSD) measured by ultrasound could serve as an objective, real-time indicator of early EBP response. In this prospective, single-center observational study, 30 postpartum patients with PDPH undergoing EBP had ONSD measured before (H0) and 2 h after (H2) the procedure. Correlation between ΔONSD and ΔVAS pain scores was analyzed with bootstrap validation, and receiver operating characteristic (ROC) analysis identified thresholds associated with early response. Mean ΔONSD was 0.97 ± 0.55 mm, significantly correlated with pain reduction (r = – 0.64, p < 0.001; bootstrap 95% CI: -0.81 to – 0.36). ROC analysis showed good diagnostic performance (AUC = 0.96, 95% CI: 0.87-1.00), with a ΔONSD ≥ 0.40 mm threshold providing 100% sensitivity and 83% specificity for early improvement. These preliminary findings suggest that ONSD ultrasound may offer a feasible, noninvasive adjunct for assessing early EBP response in PDPH. The identified 0.40 mm change threshold appears promising but requires confirmation in larger, multicenter studies with extended follow-up to determine its reproducibility and clinical utility.

PMID: 41642543  
DOI: 10.1007/s10877-025-01395-8

AUTHORS: Mazin Omer, Katharina Wolf, Manou Overstijns, Amir El Rahal, Niklas Lützen, Horst Urbach, Charlotte Zander, Laura Krismer, Jan-Helge Klingler, Marc Hohenhaus, Mukesch Shah, Jürgen Beck, Florian Volz

CITATION: Frontiers in Neurology vol. 17 (2026): 1738826. doi:10.3389/fneur.2026.1738826

🔓Open access! Full study available here. 

INTRODUCTION: Spontaneous intracranial hypotension (SIH) due to a spinal cerebrospinal fluid (CSF) leak is a debilitating but curable condition, often affecting individuals of working age, making a considerably socioeconomic impact likely.

METHODS: This monocentric retrospective study in Germany analyzed work capacity in patients ≤65 years before and after surgical closure of a spinal CSF leak between April 2018 and September 2024. The economic burden was evaluated via direct hospital costs and indirect costs from productivity losses.

RESULTS: Two hundred and ten patients (median age 45.5 years, 62% female), all physically capable of working, were included. After symptom onset, 96% could not perform their professional work as before: 61% were completely unable, 18% reduced working time, and 17% adapted conditions. Three months postoperatively, 55% had completely returned to work, 19% were working part-time. At the last follow-up these numbers further improved to 65 and 17%, respectively, only 9% were still unable to work, 9% had retired. A shorter symptom duration was significantly associated with complete return to work. Median direct costs per patient for diagnosis and treatment was €11,407, indirect costs for 160 days (the median symptom duration before surgery) averaged €21,169. Extrapolated to the incidence rate, the additional annual economic burden in Germany is estimated at €85.75 million for 160 sick days, largely from preventable productivity losses.

CONCLUSION: SIH significantly impairs working ability. Early treatment can restore work capacity and substantially reduces preventable productivity losses, strongly advocating timely intervention not only from a medical but also from an economic perspective.

PMID: 41695621
PMCID: PMC12894015
DOI: 10.3389/fneur.2026.1738826

AUTHORS: Victor Liaw, Deborah I Friedman 

CITATION: Neurology. Clinical practice vol. 16,2 (2026): e200585. doi:10.1212/CPJ.0000000000200585

BACKGROUND AND OBJECTIVES: Spontaneous intracranial hypotension (SIH) profoundly affects quality of life. We aimed to identify and quantify various aspects of patients’ experiences with SIH.

METHODS: We piloted an “SIH Impact Inventory,” a cross-sectional survey developed in collaboration with patients, family members, and caregivers. Potential participants were identified from a single center using diagnosis and procedure codes. Participants completed the inventory online using REDCap between December 2021 and April 2022.

RESULTS: Ninety-eight adult patients completed the inventory. The mean age was 50.6 years, and 69.4% were female. Sixty-three percent had a confirmed diagnosis of SIH, and 36.7% had clinically suspected but unconfirmed SIH. The mean time to diagnosis was 2.0 (interquartile range: 0.5-4.8) years; 25.5% went undiagnosed for 5 or more years, and 75% were initially misdiagnosed. The 3 most common symptoms were head pain, neck pain, and “brain fog.” Of those undergoing epidural blood patch procedures, 22% experienced relief of symptoms for a median time of 1.3 months; those with a confirmed diagnosis had more prolonged relief. 58.2% reported experiencing rebound intracranial hypertension after a therapeutic procedure. Surgical repair of the leak was most likely to result in a symptom-free status (p = 0.003) than nonsurgical treatments. Of those working for compensation when they developed SIH, 95.2% indicated that the condition affected their ability to work and 65.1% stopped working. The financial burden was substantial for 65.3% of our cohort, with medical expenses (98.4%) and travel for health care (65.6%) being the most prevalent expenses. SIH negatively affected personal and family relationships for most patients.

DISCUSSION: Individuals with confirmed and suspected SIH experience difficulties related to the disorder itself and the lengthy process of diagnosis and treatment. Our findings demonstrate the marked impact of SIH on employment, education, interpersonal relationships, and finances. Compared with previous studies, our cohort reported considerable cognitive difficulties, with rates approaching those of head pain. Heightened awareness of SIH, referral to a center with expertise in SIH, increasing the number and geographic distribution of SIH centers, and advances in diagnostic and treatment modalities can help alleviate some of the challenges that patients face.

PMID: 41626517
PMCID: PMC12854680 (available on 2027-04-01)
DOI: 10.1212/CPJ.0000000000200585

AUTHORS: Federico Cagnazzo, Andrés Ortiz Giraldo, Nicolas Lonjon, Vincent Costalat, Anne Ducros 

CITATION: Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences, 15910199261416268. 27 Jan. 2026, doi:10.1177/15910199261416268

ABSTRACT: Cerebrospinal fluid-venous fistula (CSFVF) is an increasingly recognized cause of spontaneous intracranial hypotension (SIH). We present a rare case of a 41-year-old woman with SIH caused by a right S2-S3 CSFVF draining in the right internal iliac vein. Successfully transvenous endovascular embolization using Onyx was performed. This report highlights diagnostic challenges and procedural details, emphasizing the efficacy of endovascular approaches in managing CSFVF in atypical anatomical locations.

PMID: 41591940  
PMCID: PMC12846900
DOI: 10.1177/15910199261416268

AUTHORS: Wouter I Schievink, Marcel M Maya, Andre E Boyke, Franklin G Moser, Ravi S Prasad, Vikram Wadhwa, Xuemo Fan 

CITATION: AJNR. American journal of neuroradiology, 10.3174/ajnr.A9061. 15 Jan. 2026, doi:10.3174/ajnr.A9061

BACKGROUND AND PURPOSE: Spinal CSF leaks cause spontaneous intracranial hypotension (SIH), characterized by orthostatic headaches, but the detection of these leaks may require specialized and invasive spinal imaging. We have noted the presence of small lateral dural CSF collections of unclear significance on digital subtraction myelography (DSM) in some of these patients suspected of having SIH. The purpose of the present study was to compare radiographic and anatomic intraoperative findings in patients with such small lateral dural CSF collections who underwent surgical exploration. 

MATERIALS AND METHODS: This retrospective cohort study included a consecutive group of patients suspected of having SIH who 1) did not have a spinal longitudinal extradural collection or CSF-venous fistula on spinal imaging; 2) underwent DSM under general anesthesia in the lateral decubitus position; and 3) underwent surgery for the finding of small lateral dural CSF collections of uncertain significance.  

RESULTS: The study group consisted of 27 patients (22 women and 5 men; mean age, 44.6 years; range, 16-72 years). DSM demonstrated a total of 31 small lateral dural CSF collections measuring 0.6-2.4 mm in diameter (mean, 1.3 mm) and 1.3-12.3 mm (mean, 3.5 mm) caudal to the origin of the neve root sleeve. Intraoperative exploration found evidence of a CSF leak in all 27 patients. One or more CSF-venous fistulas were found in 23 patients, and a pedicular type lateral CSF leak, in 4 patients. Radiographic differentiation between these 2 types of spinal CSF leaks could not be made with confidence.  

CONCLUSIONS: Some patients suspected of having SIH have small lateral dural CSF collections on DSM caudal to the origin of the nerve root sleeve. We have found evidence of a CSF leak in all these patients on surgical exploration. This observation expands their treatment options. 

PMID: 41539719  
DOI: 10.3174/ajnr.A9061

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

CITATION: AJNR. American journal of neuroradiology vol. 47,1 238-243. 5 Jan. 2026, doi:10.3174/ajnr.A8900

ABSTRACT: CSF-venous fistulas (CVFs) 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 CVFs has increased in recent years. Most commonly, patients harbor only 1 fistula at the time of myelography (although additional de novo fistulas can arise after treatment). Occasionally, 2 synchronous CVFs may be seen on a single myelogram. The coexistence of more than 2 CVFs, however, is quite rare and has only been previously described in 2 instances. Here, we present a multi-institutional series of 16 patients with 3 or more concurrently discovered CVFs, representing the largest cohort of such patients to date. We describe their clinical features, imaging findings, treatment approaches, and outcomes.

PMID: 40571346
PMCID: PMC12767699 (available on 2027-01-01)
DOI: 10.3174/ajnr.A8900