Abstracts 2024

AUTHORS: Alexander P Ligocki, Augustine V Vinson, Anthony T Yachnis, William A Dunn Jr, Douglas E Smith, Elizabeth A Scott, Jimena V Alvarez-Castanon, Daniel E Baez Montalvo, Olivia G Frisone, Gary A J Brown. Joel E Pessa, Edward W Scott

CITATION: Sci Adv. 2024 Sep 6;10(36):eadn3259. doi: 10.1126/sciadv.adn3259. Epub 2024 Sep 4

ABSTRACT: Cerebrospinal fluid (CSF) is responsible for maintaining brain homeostasis through nutrient delivery and waste removal for the central nervous system (CNS). Here, we demonstrate extensive CSF flow throughout the peripheral nervous system (PNS) by tracing distribution of multimodal 1.9-nanometer gold nanoparticles, roughly the size of CSF circulating proteins, infused within the lateral cerebral ventricle (a primary site of CSF production). CSF-infused 1.9-nanometer gold transitions from CNS to PNS at root attachment/transition zones and distributes through the perineurium and endoneurium, with ultimate delivery to axoplasm of distal peripheral nerves. Larger 15-nanometer gold fails to transit from CNS to PNS and instead forms “dye-cuffs,” as predicted by current dogma of CSF restriction within CNS, identifying size limitations in central to peripheral flow. Intravenous 1.9-nanometer gold is unable to cross the blood-brain/nerve barrier. Our findings suggest that CSF plays a consistent role in maintaining homeostasis throughout the nervous system with implications for CNS and PNS therapy and neural drug delivery.

PMID: 39231237
PMCID: PMC11373606
DOI: 10.1126/sciadv.adn3259

AUTHORS: Abhishek Lenka, Abhigyan Datta, Alfonso Fasano

CITATION:Tremor Other Hyperkinet Mov (NY). 2024 Sep 6:14:44. doi: 10.5334/tohm.914. eCollection 2024.

BACKGROUND: Spontaneous intracranial hypotension (SIH), a treatable condition that stems from spinal leakage of cerebrospinal fluid, usually presents with orthostatic headache, nausea, vomiting, dizziness, and tinnitus. A subset of patients, especially those with sagging of brain structures (“brain sagging syndrome”), develop several movement abnormalities. As SIH is treatable with epidural blood patch (EBP), movement disorders neurologists should be familiar with this syndrome.

METHODS: The authors performed a literature search in PubMed in July 2024 using the Boolean phrase- ((“Brain sagging”)OR(“Intracranial hypotension”))AND((((((((((“Movement disorders”)OR(“Involuntary movements”))OR(“Tremor”))OR(“Dystonia”))OR(“Chorea”))OR(“Ballismus”))OR(“Myorhythmia”))OR (“Tic”))OR(“Ataxia”))OR(“Parkinsonism”)). 

MATERIALS AND METHODS: 3D T1-weighted magnetization-prepared 2 rapid gradient echo sequences were acquired in 4 patients with SIH with proved CSF leaks and 12 patients without SIH before, 2-4, 6-8, and 24-48 hours after intrathecal gadobutrol injection. MR scans were warped to the Montreal Neurological Institute space and serial scans were coregistered. T1 relaxation times were measured in predefined ROIs including the subarachnoid space, cortex, white matter, and cervical lymph nodes.

RESULTS: We tabulated 21 case reports/series that highlighted the presence of movement disorders. The most reported phenomenology is gait unsteadiness. While it usually emerges in the background of the classic SIH symptoms, rarely, patients may present with isolated gait dysfunction. Tremor is the second most reported phenomenology with postural and kinetic tremor being the common subtypes. Holmes tremor has also been reported in SIH. Other reported phenomenologies are parkinsonism, chorea, and dystonia. One study reported a unique phenomenology i.e. compulsive repetitive flexion and breath holding in 35.3% of the patients. In majority of the patients, EBP resulted in substantial clinical and radiological improvement.

DISCUSSION: Brain sagging syndrome due to SIH may present with a wide range of movement disorders. Mechanical distortion of the posterior fossa and subcortical structures result in the emergence of such movement abnormality. SIH adds to the list of conditions that result in “treatable movement disorders.” Therefore, movement disorders neurologists should be versed with the diagnosis and clinical features of this condition.

PMID: 39246728
PMCID: PMC11378704
DOI: 10.5334/tohm.914

AUTHORS:H. Urbach, I.E. Duman Kavus, C. Zander, L. Becker, E. Kellner, M. Reisert, A. El Rahal, F. Volz, K. Wolf, J. Beck, A. Rau and N. Lützen

CITATION: AJNR Am J Neuroradiol . 2024 Sep 19. doi: 10.3174/ajnr.A8365. Online ahead of print.

BACKGROUND AND PURPOSE:The glymphatic (glia-lymphatic) system is a paravascular pathway for the clearance of waste metabolites including amyloid β from the brain. Serial T1 relaxation time measurements after the intrathecal injection of gadolinium-based contrast agents facilitate the analysis of the temporal dynamics that may be different in patients with spontaneous intracranial hypotension (SIH) and those without SIH.

METHODS: An 8‑week online survey was conducted to assess the impact of SIH on symptoms, sociodemographics and quality of life. The cohort was comprised of patients who had a self-reported diagnosis of SIH and were divided into two groups: those with radiological evidence of SIH and those with clinical suspicion but no radiological evidence. Mental health and disability were evaluated using the Depression, Anxiety and Stress Scale-21 (DASS-21) and the Henry Ford Hospital Headache Disability Inventory (HDI).

MATERIALS AND METHODS: 3D T1-weighted magnetization-prepared 2 rapid gradient echo sequences were acquired in 4 patients with SIH with proved CSF leaks and 12 patients without SIH before, 2-4, 6-8, and 24-48 hours after intrathecal gadobutrol injection. MR scans were warped to the Montreal Neurological Institute space and serial scans were coregistered. T1 relaxation times were measured in predefined ROIs including the subarachnoid space, cortex, white matter, and cervical lymph nodes.

RESULTS: In the subarachnoid space and cortex, T1 relaxation times decreased after 2-4 and 6-8 hours before they increased again. In contrast, in the white matter of the temporal lobe T1 relaxation time still decreased after 24-48 hours. There was a striking difference in patients with SIH who did not show a clear contrast distribution within the brain parenchyma.

CONCLUSIONS: T1 relaxation time curves are compatible with a convective flow driven by arterial pulsations via paravascular spaces surrounding penetrating arteries into the brain’s interstitial fluid in the deep white matter. Different curves in patients with SIH and those without SIH indicate that the CSF pressure also impacts the temporal kinetics of the glymphatic system.

PMID: 39299796
DOI: 10.3174/ajnr.A8365

AUTHORS: Ali Kapan PhD, Thomas Waldhör PhD & Christian Wöber MD

CITATION: Wien Klin Wochenschr. 2024 Sep 3. doi: 10.1007/s00508-024-02423-4. Online ahead of print.

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BACKGROUND: Spontaneous intracranial hypotension (SIH), characterized by headaches due to cerebrospinal fluid leaks or low pressure, is a challenging condition to diagnose and treat and affects the quality of life.

METHODS: An 8‑week online survey was conducted to assess the impact of SIH on symptoms, sociodemographics and quality of life. The cohort was comprised of patients who had a self-reported diagnosis of SIH and were divided into two groups: those with radiological evidence of SIH and those with clinical suspicion but no radiological evidence. Mental health and disability were evaluated using the Depression, Anxiety and Stress Scale-21 (DASS-21) and the Henry Ford Hospital Headache Disability Inventory (HDI).

RESULTS: A total of 86 participants were included in the study, 59 with radiological evidence and 27 without. Most participants were female (84.9%) with a mean age of 44.8 years. Orthostatic headache was more common in participants without radiological evidence (74.1% vs. 42.4%). The severity in those with radiological evidence was 27.1% mild, 27.1% moderate, 30.5% severe and 15.3% extremely severe, while those without had 7.4% mild, 18.5% moderate, 63.0% severe and 11.1% extremely severe headaches. Mental health assessment using the DASS-21 scale showed that 77.9% of all participants reported signs of depression, 96.5% reported anxiety and 89.5% reported stress. The HDI showed 2.3% total disability, 40.7% severe, 19.8% moderate and 37.2% mild. The impact on employment was significant: 15.1% were able to work full-time, 48.8% part-time, 30.2% were unable to work and 5.8% retired early due to SIH.

CONCLUSIONS: The study demonstrates the broad impact of SIH affecting physical health, mental well-being, and socioeconomic status, and calls for multifaceted and robust management approaches to address its complex effects on patients.

AUTHORS: Angelique Sao-Mai S Tay, Marcel M Maya, Wouter I Schievink

CITATION: Headache. 2024 Sep 2. doi: 10.1111/head.14826. Online ahead of print.

OBJECTIVE: To raise awareness that patients with persistent post-dural puncture headache should be considered for evaluation of spontaneous cerebrospinal fluid (CSF) leak.

BACKGROUND AND PURPOSE: Spontaneous intracranial hypotension (SIH) due to a spinal CSF leak may occur following more-or-less trivial traumatic events. We report our experience with spontaneous spinal CSF leaks that occur following percutaneous or open spine procedures, a potential source of diagnostic confusion.

METHODS: In a retrospective cohort study, using a prospectively maintained database of patients with SIH, we identified all new patients evaluated between January 1, 2022, and June 30, 2023, who were referred for evaluation of an iatrogenic spinal CSF leak but were found to have a spontaneous spinal CSF leak.

RESULTS: Nine (4%) of the 248 patients with SIH were originally referred for evaluation of an iatrogenic spinal CSF leak. The spinal procedures included epidural steroid injections, laminectomies, epidural anesthesia, and lumbar puncture. Brain magnetic resonance imaging (MRI) showed changes in intracranial hypotension in seven of the nine patients (78%). The spontaneous CSF leak was found to be at least five levels removed from the spinal procedure in all patients.

CONCLUSIONS: A spontaneous spinal CSF leak should be suspected in patients with recalcitrant orthostatic headaches following a spinal procedure, even if symptoms of the leak occur within hours of the spinal procedure and especially if brain MRI is abnormal.

PMID: 39221817
DOI: 10.1111/head.14826

AUTHORS: Andrew L Callen, Lichy Han, Samantha L Pisani Petrucci, Nadya Andonov, Peter Lennarson, Marius Birlea, Chantal O’Brien, Danielle Wilhour, Abigail Anderson, Jeffrey L Bennett, Ian R Carroll.

CITATION: Headache. 2024 Sep;64(8):939-949. doi: 10.1111/head.14805. Epub 2024 Aug 11.

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OBJECTIVE: To identify distinct clinical or imaging subtypes of spontaneous intracranial hypotension (SIH) due to spinal cerebrospinal fluid (CSF) venous fistula (CVF).

BACKGROUND AND PURPOSE: Spontaneous intracranial hypotension is classically understood to present clinically with an orthostatic headache and stereotyped brain magnetic resonance imaging (MRI) findings; however, most prior literature examining clinical and brain MRI features of SIH has focused on all types of spinal CSF leaks concurrently. This study aimed to evaluate whether data support the possibility of internally consistent subtypes based on brain imaging features and clinical symptoms analogous to those seen in primary headache syndromes.

AUTHORS: Ian T. Mark, Waleed Brinjikji, Jeremy Cutsforth-Gregory, Jared T. Verdoorn, John C. Benson, Ajay A. Madhavan and Jeff W. Meeusen

CITATION: AJNR Am J Neuroradiol. 2024 Aug 24:ajnr.A8476. doi: 10.3174/ajnr.A8476. Online ahead of print.

BACKGROUND AND PURPOSE: Accurately identifying patients with CSF-venous fistulas (CVF), one cause of spontaneous intracranial hypotension (SIH), is a diagnostic dilemma. This conundrum underscores the need for a CVF biomarker to help select who should undergo an invasive myelogram for further diagnostic workup. Beta trace protein (BTP) is the most abundant CNS derived protein in the CSF and therefore is a potential venous biomarker for CVF detection. The purpose of our study was to measure venous BTP levels as a potential CVF biomarker.

MATERIALS AND METHODS: We prospectively enrolled 14 patients with CVF and measured BTP in venous blood samples from the paraspinal veins near the CVF and compared those levels to the peripheral blood. Myelograms used initially to identify the CVF were evaluated for modality, CVF laterality, CVF level, and venous drainage pattern. Patient sex, patient age, and symptom duration were also collected. Brain MR images were reviewed for Bern scores. We also measured the peripheral blood BTP levels in 20 normal controls.

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

CITATION: AJNR Am J Neuroradiol. 2024 Aug 14:ajnr.A8445. doi: 10.3174/ajnr.A8445. Online ahead of print.

ABSTRACT: Patients with spontaneous intracranial hypotension caused by type 1 dural defects typically have an epidural fluid collection on MRI, but 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 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 to localise 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 non-invasively. Importantly, this sign was only observed on 2D T2-weighted and STIR images and not on 3D acquisitions, which notably suppress artefact. This has implications for optimal MRI spine protocol construction. This sign can be used to limit myelographic range, reduce radiation dose and may increase diagnostic confidence to dural defect location.

PMID: 39134372
DOI: 10.3174/ajnr.A8445

AUTHORS:Mark D. Mamlouk, Adriana Gutierrez and William P. Dillon

CITATION: AJNR Am J Neuroradiol. 2024 Aug 23:ajnr.A8471. doi: 10.3174/ajnr.A8471. Online ahead of print.

SUMMARY: Spinal CSF leaks from dural tears or CSF-venous fistulas are the most common causes of spontaneous intracranial hypotension. Rarely, CSF leaks have also been associated with vascular malformations, which have primarily been discussed in case reports or small series. In this clinical report, we report the clinical features, imaging findings, and treatment of 6 children and adults with CSF leaks associated with vascular malformations in the spine and skull base depicted on CT myelography and cisternography.

PMID: 39179296
DOI: 10.3174/ajnr.A8471

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

CITATION:AJNR Am J Neuroradiol. 2024 Aug 9;45(8):1162-1165. doi: 10.3174/ajnr.A8291.

AUTHORS: Derrek Schartz, Alan Finkelstein, Jianhui Zhong, Waleed Brinjikji and Matthew T. Bender

CITATION:AJNR Am J Neuroradiol. July 2024, 45 (7) 961-964; DOI: https://doi.org/10.3174/ajnr.A8229

ABSTRACT: Spontaneous intracranial hypotension is characterized by symptoms of low intracranial CSF volume due to various mechanisms of CSF leakage. One such mechanism is a CSF-venous fistula, treatable with transvenous embolization resulting in substantial radiographic and clinical improvement. However, the exact mechanisms underlying these improvements, including the potential involvement of the glymphatic system, remain unclear. To noninvasively assess glymphatic clearance in spontaneous intracranial hypotension, we used an advanced MR imaging technique called the DTI along the perivascular spaces in 3 patients with CSF-venous fistula before and after embolization. All 3 patients with spontaneous intracranial hypotension initially had low glymphatic flow, which improved postembolization. Two patients with symptomatic improvement exhibited a more substantial increase in glymphatic flow compared with a patient with minimal improvement. These findings suggest a possible link between cerebral glymphatics in spontaneous intracranial hypotension pathophysiology and symptomatic improvement, warranting larger studies to explore the role of the glymphatic system in spontaneous intracranial hypotension.

PMID: 38697791
PMCID: PMC11286014
DOI: 10.3174/ajnr.A8229

AUTHORS: Ian T Mark, Jeremy Cutsforth-Gregory, Patrick Luetmer, Ajay A Madhavan, Michael Oien, Paul Farnsworth, Girish Bathla, Steve Messina, Michael Link, Jamie Van Gompel

CITATION: AJNR Am J Neuroradiol. 2024 Aug 15. doi: 10.3174/ajnr.A8333. Online ahead of print.

AUTHORS:Niklas Lützen, Katharina Wolf, Amir El Rahal, Florian Volz, Theo Demerath, Charlotte Zander, Claus Christian Pieper, Marius Schwabenland, Horst Urbach, Jürgen Beck.

CITATION: J Neurol. 2024 Aug 6. doi: 10.1007/s00415-024-12598-5. Online ahead of print.

AUTHORS: Wouter I. Schievink, Marcel M. Maya, Angelique Sao-Mai S. Tay, Rachelle B. Taché, Ravi S. Prasad, Vikram Wadhwa and Miriam Nuño

CITATION:AJNR Am J Neuroradiol. 2024 Jul 8;45(7):951-956. doi: 10.3174/ajnr.A8261.

AUTHORS:Horst Urbach, A El Rahal, K Wolf, C Zander, T Demerath, F Volz, J Beck, N Lützen.

CITATION: Neuroradiology. 2024 Jul 10. doi: 10.1007/s00234-024-03425-9. Online ahead of print.

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BACKGROUND AND PURPOSE: Around 5% of dementia patients have a treatable cause. To estimate the prevalence of two rare diseases, in which the treatable cause is at the spinal level.

METHODS: A radiology information system was searched using the terms CT myelography and the operation and classification system (OPS) code 3-241. The clinical charts of these patients were reviewed to identify patients with a significant cognitive decline.

RESULTS:  Among 205 patients with spontaneous intracranial hypotension (SIH) and proven CSF leaks we identified five patients with a so-called frontotemporal brain sagging syndrome: Four of those had CSF venous fistulas and significantly improved by occluding them either by surgery or transvenous embolization. Another 11 patients had infratentorial hemosiderosis and hearing problems and ataxia as guiding symptoms. Some cognitive decline was present in at least two of them. Ten patients had ventral dural tears in the thoracic spine and one patient a lateral dural tear at C2/3 respectively. Eight patients showed some improvement after surgery.

CONCLUSIONS: It is mandatory to study the (thoracic) spine in cognitively impaired patients with brain sagging and/ or infratentorial hemosiderosis on MRI. We propose the term spinal dementia to draw attention to this region, which in turn is evaluated with dynamic digital subtraction and CT myelography.

PMID: 3898532
DOI: 10.1007/s00234-024-03425-9

AUTHORS: Niklas Lützen, Charlotte Zander, Rick Dersch, Jürgen Beck, Horst Urbach

CITATION:Neuroradiol J. 2024 Jul 31:19714009241269487. doi:10.1177/19714009241269487.

ABSTRACT: CSF-venous fistulas (CVFs) are an important cause of spontaneous intracranial hypotension and challenging to diagnose. Lateral decubitus positioning during myelography and a technique called “resisted inspiration” has shown to improve CVF detection. However, the impact of intrathecal pressurization to improve visualization of CVF has mostly been speculated on. In this brief report, we demonstrate how a CVF became progressively more visible only after stepwise intrathecal pressurization: An indication of the importance of pressurization for CVF detection.

PMID: 39081205
DOI: 10.1177/19714009241269487

AUTHORS: Waleed Brinjikji, Ajay Madhavan, Ivan Garza, Mark Whealy, Narayan Kissoon, Ian Mark, Pearse P Morris, Jared Verdoorn, John C Benson, John L D Atkinson, Hassan Kobeissi, Jeremy K Cutsforth-Gregory

CITATION: J Neurointerv Surg. 2024 Jun 27:jnis-2023-021012. doi: 10.1136/jnis-2023-021012. Online ahead of print..

BACKGROUND: Cerebrospinal fluid-venous fistulas (CSFVF) are a common cause of spontaneous intracranial hypotension (SIH). Transvenous embolization has emerged as a reliable treatment option. We review the clinical presentation, imaging, and clinical outcomes of 100 consecutive CSFVF patients who underwent embolization over 2 years.

METHODS:Baseline clinical characteristics, imaging findings (including Bern SIH score), technical outcomes, and long-term imaging and clinical outcomes were collected. All patients had at least 3 months of clinical follow-up and had baseline MRI. 99/100 patients underwent follow-up imaging at ≥3 months post-treatment.

RESULTS: 100 patients were included. Mean imaging and clinical follow-up duration was 8.3±7.7 months and 15.0±6.8 months, respectively. The mean duration of symptoms before embolization was 40.9±52 months. Mean baseline Bern SIH score was 5.9±3.3. The most common baseline symptoms were headache (96 patients), tinnitus (55 patients), and cognitive dysfunction (44 patients). Technical success rate was 100%. Mean post-treatment Bern SIH score was 0.9±1.6 (P<0.0001). Following treatment, 95% of patients reported significant improvement or resolution in symptoms (58 patients reporting resolution and 37 reporting improvement). 5 patients reported no improvement. There were no major procedural or periprocedural complications. 10 patients had minor procedural complications that did not result in any change in management (Onyx emboli, venous perforation). 19 patients had rebound intracranial hypertension requiring acetazolamide therapy. 7 patients had recurrent fistula at the initially treated level.

CONCLUSION: Transvenous embolization of CSFVF in SIH patients is safe and effective with a 95% treatment response, significant improvement in imaging outcomes, and a very low rate of complications.

PMID: 37898553
DOI: 10.1136/jnis-2023-021012

AUTHORS: Ali Kapan PhD, Thomas Waldhör PhD, Tobias Schiffler MSc, Jürgen Beck MD, Christian Wöber MD

CITATION: Headache. 2024 Jul 16. doi: 10.1111/head.14790.

BACKGROUND: Post-dural puncture headache (PDPH) is a frequent complication following lumbar puncture, epidural analgesia, or neuraxial anesthesia. The International Classification of Headache Disorders, third edition categorizes PDPH as a self-limiting condition; however, emerging evidence, including our findings, suggests that PDPH can have a prolonged course, challenging this traditional view.

OBJECTIVES: To elucidate the diagnostic characteristics and treatment outcomes of persistent PDPH (pPDPH), offering insights into its demographic profiles and diagnostic features.

METHODS: We executed an anonymous, web-based survey targeting individuals aged ≥18 years diagnosed with or suspected of having pPDPH. Recruitment occurred through self-help groups on Facebook. The survey comprised questions regarding diagnostic procedures, treatment regimens, outcomes, and healthcare consultation.

RESULTS: The survey achieved a response rate of 179/347 (51.6%) individuals completing the questionnaire. Cerebrospinal fluid (CSF) leaks were confirmed in nine of 179 (5.0%) cases. Signs of intracranial hypotension without a CSF leak were observed in 70/179 (39.1%) individuals. All participants underwent magnetic resonance imaging scans of the brain and spine, with computed tomography myelography performed in 113/179 (63.1%) cases. Medications, including analgesics, theophylline, and gabapentin, provided minimal short-term relief. Epidural blood patch treatments resulted in slight-to-moderate short-term improvement in 136/179 (76.0%), significant improvement in 22/179 (12.3%), and complete effectiveness in eight of 179 (4.5%) individuals. For long-term outcomes, slight-to-moderate improvement was reported by 118/179 (66.0%) individuals. Surgical interventions were carried out in 42/179 (23.5%) patients, revealing pseudomeningoceles intraoperatively in 20/42 (47.6%) individuals. After surgery, 21/42 (50.0%) of the participants experienced slight-to-moderate improvement, 12/42 (28.6%) showed more pronounced improvement, and five of the 42 (11.9%) achieved complete effectiveness.

CONCLUSION: This study underscores the complexities of managing pPDPH. The delay in diagnosis can impact the effectiveness of treatments, including epidural blood patch and surgical interventions, resulting in ongoing symptoms. This underscores the importance of tailored and adaptable treatment strategies. The findings advocate for additional research to deepen the understanding of pPDPH and improve long-term patient outcomes.

PMID: 39012072
DOI: 10.1111/head.14790

AUTHORS: Vishal Uppal, Robin Russell, Rakesh V Sondekoppam, Jessica Ansari, Zafeer Baber, Yian Chen, Kathryn DelPizzo, Dan Sebastian Dirzu, Hari Kalagara, Narayan R Kissoon, Peter G Kranz, Lisa Leffert, Grace Lim, Clara Lobo, Dominique Nuala Lucas, Eleni Moka, Stephen E Rodriguez, Herman Sehmbi, Manuel C Vallejo, Thomas Volk, Samer Narouze

CITATION: Reg Anesth Pain Med. 2024 Jul 8;49(7):471-501. doi: 10.1136/rapm-2023-104817.

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INTRODUCTION: Postdural puncture headache (PDPH) can follow unintentional dural puncture during epidural techniques or intentional dural puncture during neuraxial procedures such as a lumbar puncture or spinal anesthesia. Evidence-based guidance on the prevention, diagnosis or management of this condition is, however, currently lacking. This multisociety guidance aims to fill this void and provide practitioners with comprehensive information and patient-centric recommendations to prevent, diagnose and manage patients with PDPH.

METHODS: Based on input from committee members and stakeholders, the committee cochairs developed 10 review questions deemed important for the prevention, diagnosis and management of PDPH. A literature search for each question was performed in MEDLINE (Ovid) on 2 March 2022. The results from each search were imported into separate Covidence projects for deduplication and screening, followed by data extraction. Additional relevant clinical trials, systematic reviews and research studies published through March 2022 were also considered for the development of guidelines and shared with contributors. Each group submitted a structured narrative review along with recommendations graded according to the US Preventative Services Task Force grading of evidence. The interim draft was shared electronically, with each collaborator requested to vote anonymously on each recommendation using two rounds of a modified Delphi approach.

RESULTS: Based on contemporary evidence and consensus, the multidisciplinary panel generated 50 recommendations to provide guidance regarding risk factors, prevention, diagnosis and management of PDPH, along with their strength and certainty of evidence. After two rounds of voting, we achieved a high level of consensus for all statements and recommendations. Several recommendations had moderate-to-low certainty of evidence.

CONCLUSIONS: These clinical practice guidelines for PDPH provide a framework to improve identification, evaluation and delivery of evidence-based care by physicians performing neuraxial procedures to improve the quality of care and align with patients’ interests. Uncertainty remains regarding best practice for the majority of management approaches for PDPH due to the paucity of evidence. Additionally, opportunities for future research are identified.

PMID: 37582578
DOI: 10.1136/rapm-2023-104817

AUTHORS: Emma M.Z. Sechrist, Samantha L. Pisani Petrucci, Nadya Andonov, Peter Lennarson, Andrew L. Callen

CITATION: AJNR Am J Neuroradiol. 2024 Jul 8;45(7):957-960. doi:10.3174/ajnr.A8247

BACKGROUND AND PURPOSE: CSF venous fistula leads to spontaneous intracranial hypotension. The exact mechanisms underlying the development of CSF venous fistula remain unclear: Some researchers have postulated that underlying chronic intracranial hypertension may lead to damage to spinal arachnoid granulations, given that many patients with CSF venous fistulas have an elevated body mass index (BMI). However, individuals with higher BMIs are also more prone to spinal degenerative disease, and individuals with CSF venous fistulas also tend to be older. CSF venous fistula tends to occur in the lower thoracic spine, the most frequent location of thoracic degenerative changes. The current study aimed to examine whether CSF venous fistulas are more likely to occur at spinal levels with degenerative changes.

MATERIALS AND METHODS: Forty-four consecutive patients with CSF venous fistulas localized on dynamic CT myelography were included in analyses. Whole-spine CT was scrutinized for the presence of degenerative changes at each spinal level. The proportion of levels positive for CSF venous fistula containing any degenerative findings was compared to levels without CSF venous fistula using the Fisher exact test. The Pearson correlation coefficient was calculated to explore the association between the burden of degenerative disease and BMI and age and between BMI and opening pressure.

RESULTS: Forty-four patients with 49 total CSF venous fistulas were analyzed (5 patients had 2 CSF venous fistulas). Mean patient age was 62.3 (SD, 9.5) years. Forty-seven CSF venous fistulas were located in the thoracic spine; 1, in the cervical spine; and 1, in the lumbar spine. Within the thoracic spine, 39/49 (79.6%) fistulas were located between levels T7–8 and T12–L1. Forty-four of 49 (89.8%) CSF venous fistulas had degenerative changes at the same level. The levels without CSF venous fistulas demonstrated degenerative changes at 694/1007 (68.9%) total levels. CSF venous fistulas were significantly more likely to be present at spinal levels with associated degenerative changes (OR = 4.03; 95% CI, 1.58-10.27; P = .001). Age demonstrated a positive correlation with the overall burden of degenerative disease (correlation coefficient: 0.573, P < .001), whereas BMI did not (correlation coefficient: 0.076, P = .625). There was a statistically significant positive correlation between BMI and opening pressure (correlation coefficient: 0.321, P = .03).

CONCLUSIONS: Results suggest a potential association between spinal degenerative disease and development of CSF venous fistula.

PMID: 38697794
PMCID: PMC11286032
DOI: 10.3174/ajnr.A8247

AUTHORS:John K Chae, Kate Rosen, Kyle Zappi, Alexandra Giantini-Larsen, Jenny Yan, Jeffrey Sung, Evan Bander, Theodore H Schwartz, John K Park, Gayle Salama.

CITATION: World Neurosurg. 2024 Jul:187:288-293. doi: 10.1016/j.wneu.2024.03.111.

ABSTRACT:Cerebrospinal fluid (CSF) leaks may occur at the skull base or along the spinal column and can cause a variety of debilitating neurological symptoms for patients. Recognizing the potential presence of a CSF leak and then identifying its source are necessary for accurate diagnosis and definitive treatment. A standardized workflow can be followed for successful leak localization, which often requires several diagnostic studies, and for definitive leak treatment, which can range from minimally invasive, needle-based approaches to a variety of surgical corrections. This review paper provides an overview of epidemiology, pathophysiology, and diagnostic workup for CSF leaks and introduces available treatment options. An illustrative case of a skull base CSF leak demonstrating diagnosis and surgical correction is provided.

PMID: 38970199
DOI: 10.1016/j.wneu.2024.03.111

AUTHORS: Jeffrey Sung, Matthew Lin, Alexandra Giantini-Larsen, Andrew Kim, David Edasery, Michelle Roytman, Sara Strauss, Andrew D Schweitzer, John K Park, Gayle Salama.

CITATION: World Neurosurg. 2024 Jul:187:294-303. doi: 10.1016/j.wneu.2024.03.114.

ABSTRACT:The confirmation of cerebrospinal fluid (CSF) leaks in the setting of spontaneous intracranial hypotension (SIH) by imaging involves a growing toolset of multimodal advanced spinal and skull base imaging techniques, for which exists a unique set of challenges for each CSF leak type. Furthermore, the repertoire of minimally invasive CSF leak treatment beyond nontargeted epidural blood patch administration has grown widely, with varied practices across institutions. This review describes current diagnostic imaging and treatment modalities as they apply to the challenges of CSF leak localization and management.

PMID: 38970200
DOI: 10.1016/j.wneu.2024.03.114

AUTHORS: Kyle Zappi, Alexandra Giantini-Larsen, Jenny Yan, Mawa Konate, Andrew L A Garton, Jared Knopman, Philip E Stieg, Gayle Salama, John K Park.

CITATION: World Neurosurg. 2024 Jul:187:304-312. doi: 10.1016/j.wneu.2024.03.112.

ABSTRACT: Spontaneous spinal cerebrospinal fluid (CSF) leaks are uncommon but can be neurologically debilitating. When initial treatments fail, definitive repair or closure of the leak is indicated. Depending upon the type of leak present, innovative strategies for their treatment have been developed. Among them are open surgical techniques using a transdural approach for the closure of ventral CSF leaks, minimally invasive tubular techniques for the reduction and repair of lateral meningeal diverticula, and endovascular embolization of CSF-venous fistulas. Illustrative cases demonstrating the indications for and implementation of these techniques are provided.

PMID: 38970201
DOI: 10.1016/j.wneu.2024.03.112

AUTHORS:Wouter I Schievink, Marcel M Maya, Angelique Sao-Mai S Tay, Rachelle B Taché, Ravi S Prasad, Vikram Wadhwa, Miriam Nuño

CITATION: AJNR Am J Neuroradiol. Published online June 13, 2024. doi:10.3174/ajnr.A8261

BACKGROUND AND PURPOSE: Spinal CSF leaks cause spontaneous intracranial hypotension. Several types of leaks have been identified, and one of these types is the lateral dural tear. Performing myelography with the patient in the decubitus position allows precise characterization of these leaks. The purpose of the current study was to describe the different variants of spontaneous lateral CSF leaks.

MATERIALS AND METHODS: This retrospective cohort study included a consecutive group of patients with spontaneous intracranial hypotension and lateral CSF leaks who underwent digital subtraction myelography in the decubitus position and underwent surgery to repair the CSF leak between July 2018 and June 2023.

RESULTS: The mean age of the 53 patients (37 women and 16 men) was 35.5 years. Three different variants of lateral CSF leak could be identified. Forty-nine patients (92.5%) had a lateral dural tear associated with the nerve root sleeve. The dural tear was at the axilla of the nerve root sleeve in 36 patients (67.9%) and at the shoulder in 13 patients (24.5%). Four patients (7.5%) had a lateral dural tear at the level of the pedicle that was not associated with the nerve root sleeve. Findings on digital subtraction myelography were concordant with intraoperative findings in all patients. An extradural CSF collection was seen in all patients with a lateral dural tear associated with the nerve root sleeve but in only 2 of the 4 patients with the pedicular variant of a lateral dural tear.

CONCLUSIONS: We identified 3 variants of spontaneous lateral dural tears. Most lateral dural tears are associated with extradural CSF collections and arise from either the axilla (67.9%) or the shoulder (24.5%) of the nerve root sleeve. Lateral dural tears at the level of the pedicle (7.5%) not associated with the nerve root sleeve are uncommon and may require specialized imaging for their detection.

PMID: 38871369
DOI: 10.3174/ajnr.A8261

AUTHORS: Ian T Mark, Pragalv Karki, Jeremy Cutsforth-Gregory, Waleed Brinjikji, Ajay A Madhavan, Steven A Messina, Petrice M Cogswell, John J Chen, Richard L Ehman, John Huston, Matthew C Murphy.

CITATION:  AJNR Am J Neuroradiol. 2024;45(5):662-667. Published 2024 May 9. doi:10.3174/ajnr.A8162

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BACKGROUND AND PURPOSE: Spontaneous intracranial hypotension is a condition resulting from a leak of CSF from the spinal canal arising independent of a medical procedure. Spontaneous intracranial hypotension can present with normal brain MR imaging findings and nonspecific symptoms, leading to the underdiagnosis in some patients and unnecessary invasive myelography in others who are found not to have the condition. Given the likelihood that spontaneous intracranial hypotension alters intracranial biomechanics, the goal of this study was to evaluate MR elastography as a potential noninvasive test to diagnose the condition.

MATERIALS AND METHODS:We performed MR elastography in 15 patients with confirmed spontaneous intracranial hypotension from September 2022 to April 2023. Age, sex, symptom duration, and brain MR imaging Bern score were collected. MR elastography data were used to compute stiffness and damping ratio maps, and voxelwise modeling was performed to detect clusters of significant differences in mechanical properties between patients with spontaneous intracranial hypotension and healthy control participants. To evaluate diagnostic accuracy, we summarized each examination by 2 spatial pattern scores (one each for stiffness and damping ratio) and evaluated group-wise discrimination by receiver operating characteristic curve analysis.

RESULTS: Patients with spontaneous intracranial hypotension exhibited significant differences in both stiffness and damping ratio (false discovery rate-corrected, Q < 0.05). Pattern analysis discriminated patients with spontaneous intracranial hypotension from healthy controls with an area under the curve of 0.97 overall, and the area under the curve was 0.97 in those without MR imaging findings of spontaneous intracranial hypotension.

CONCLUSION: Results from this pilot study demonstrate MR elastography as a potential imaging biomarker and a noninvasive method for diagnosing spontaneous intracranial hypotension, including patients with normal brain MR imaging findings.

PMID: 38485194
DOI: 10.3174/ajnr.A8162

AUTHORS: Ian Carroll, MD, Lichy Han, MD, PhD, Niushen Zhang, MD, Robert P. Cowan, MD, Bryan Lanzman, MD, Syed Hashmi, MD, Meredith J. Barad, MD, Addie Peretz, MD, Leon Moskatel, MD, Oyindamola Ogunlaja, MBBS, MSc, Jennifer M. Hah, MD, Nada Hindiyeh, MD, Carol Barch, MN, Selene Bozkurt, PhD, Tina Hernandez-Boussard, PhD, and Andrew L. Callen, MD

CITATION: Neurology® 2024;102:e209449. doi:10.1212/WNL.0000000000209449

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BACKGROUND AND PURPOSE:Spinal CSF leaks lead to spontaneous intracranial hypotension (SIH). While International Classification of Headache Disorders, Third Edition (ICHD-3) criteria necessitate imaging confirmation or low opening pressure (OP) for SIH diagnosis, their sensitivity may be limited. We offered epidural blood patches (EBPs) to patients with symptoms suggestive of SIH, with and without a documented low OP or confirmed leak on imaging. This study evaluates the efficacy of this strategy.

MATERIALS AND METHODS: We conducted a prospective cohort study with a nested case-control design including all patients who presented to a tertiary headache clinic with clinical symptoms of SIH who completed study measures both before and after receiving an EBP between August 2016 and November 2018.

RESULTS: The mean duration of symptoms was 8.7 ± 8.1 years. Of 85 patients assessed, 69 did not meet ICHD-3 criteria for SIH. At an average of 521 days after the initial EBP, this ICHD-3–negative subgroup experienced significant improvements in Patient-Reported Outcomes Measurement Information System (PROMIS) Global Physical Health score of +3.3 (95% CI 1.5–5.1), PROMIS Global Mental Health score of +1.8 (95% CI 0.0–3.5), Headache Impact Test (HIT)-6 head pain score of −3.8 (95% CI −5.7 to −1.8), Neck Disability Index of −4.8 (95% CI −9.0 to −0.6) and PROMIS Fatigue of −2.3 (95% CI −4.1 to −0.6). Fifty-four percent of ICHD-3–negative patients achieved clinically meaningful improvements in PROMIS Global Physical Health and 45% in HIT-6 scores. Pain relief following lying flat prior to treatment was strongly associated with sustained clinically meaningful improvement in global physical health at an average of 521 days (odds ratio 1.39, 95% CI 1.1–1.79; p < 0.003). ICHD-3–positive patients showed high rates of response and previously unreported, treatable levels of fatigue and cognitive deficits.

DISCUSSION: Patients who did not conform to the ICHD-3 criteria for SIH showed moderate rates of sustained, clinically meaningful improvements in global physical health, global mental health, neck pain, fatigue, and head pain after EBP therapy. Pre-treatment improvement in head pain when flat was associated with later, sustained improvement after EBP therapy among patients who did not meet the ICHD-3 criteria.

CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that epidural blood patch is an effective treatment of suspected CSF leak not conforming to ICHD-3 criteria for SIH.

PMID: 38820488
DOI: 10.1212/WNL.0000000000209449

AUTHORS: Andrew L. Callen, MD, Deborah I. Friedman, MD, Simy Parikh, MD, Jill C. Rau, MD, PhD, Wouter I. Schievink, , Jeremy K. Cutsforth-Gregory, MD, Timothy J. Amrhein, MD, Elena Haight, MD, Robert P. Cowan, MD, Meredith J. Barad, MD, Jennifer M. Hah, MD, Tracy Jackson, MD, Connie Deline, MD, Andrea J. Buchanan, and Ian Carroll, MD, MS

CITATION: Neurology: Clinical Practice, June 2024 issue 14 (3), DOI: 10.1212/CPJ.0000000000200290

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PURPOSE OF REVIEW. This review focuses on the challenges of diagnosing and treating spontaneous intracranial hypotension (SIH), a condition caused by spinal CSF leakage. It emphasizes the need for increased awareness and advocates for early and thoughtful use of empirical epidural blood patches (EBPs) in suspected cases.

RECENT FINDINGS. SIH diagnosis is hindered by variable symptoms and inconsistent imaging results, including normal brain MRI and unreliable spinal opening pressures. It is crucial to consider SIH in differential diagnoses, especially in patients with connective tissue disorders. Early EBP intervention is shown to improve outcomes.

SUMMARY. SIH remains underdiagnosed and undertreated, requiring heightened awareness and understanding. This review promotes proactive EBP use in managing suspected SIH and calls for continued research to advance diagnostic and treatment methods, emphasizing the need for innovative imaging techniques for accurate diagnosis and timely intervention.

PMID: 38699599
PMCID: PMC11065326
DOI: 10.1212/CPJ.0000000000200290

AUTHORS: Andrew L. Callen, Samantha L. Petrucci Pisani, Peter Lennarson, Marius Birlea, Jennifer MacKenzie, Andrea J. Buchanan, and the “Spinal CSF Leak: Bridging the Gap” Study Group

CITATION: American Journal of Neuroradiology July 2024, DOI: 10.3174/ajnr.A8181

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BACKGROUND AND PURPOSE: The inaugural “Spinal CSF Leak: Bridging the Gap” Conference was organized to address the complexities of diagnosing and treating spinal CSF leaks. This event aimed to converge the perspectives of clinicians, researchers, and patients with a patient-centered focus to explore the intricacies of spinal CSF leaks across 3 main domains: diagnosis, treatment, and aftercare.

MATERIALS AND METHODS: Physician and patient speakers were invited to discuss the varied clinical presentations and diagnostic challenges of spinal CSF leaks, which often lead to misdiagnosis or delayed treatment. Patient narratives were interwoven with discussions on advanced radiologic techniques and clinical assessments. Treatment-focused sessions highlighted patient experiences with various therapeutic options, including epidural blood patches, surgical interventions, and percutaneous and endovascular therapies. The intricacies of immediate and long-term post-procedural management were explored.

RESULTS:Key outcomes from the conference included the recognition of the need for increased access to specialized CSF leak care for patients and heightened awareness among health care providers, especially for atypical symptoms and presentations. Discussions underscored the variability in individual treatment responses and the necessity for personalized diagnostic and treatment algorithms. Postprocedural challenges such as managing incomplete symptom relief and rebound intracranial hypertension were also addressed, emphasizing the need for effective patient monitoring and follow-up care infrastructures.

CONCLUSIONS: The conference highlighted the need for adaptable diagnostic protocols, collaborative multidisciplinary care, and enhanced patient support. These elements are vital for improving the recognition, diagnosis, and management of spinal CSF leaks, thereby optimizing patient outcomes and quality of life. The event established a foundation for future advancements in spinal CSF leak management, advocating for a patient-centered model that harmonizes procedural expertise with an in-depth understanding of patient experiences.

AUTHORS: Ali Kapan, Thomas Waldhör, Tobias Schiffler, Jürgen Beck, Christian Wöber

CITATION: Journal of Headache and Pain 25, 64 (2024). DOI: 10.1186/s10194-024-01765-8

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BACKGROUND AND OBJECTIVE: Postdural puncture headache (PDPH) is an acknowledged consequence of procedures like lumbar punctures, epidural analgesia, and neurosurgical interventions. Persistence over more than three months, however has been poorly studied. In particular, little is known about the impact of persistent PDPH (pPDPH) on health related quality of life (HRQoL), disability and ability to work. The study aimed to provide a holistic understanding of pPDPH, encompassing medical, physical and psychological aspects.

METHODS: We conducted a cross-sectional anonymous online survey in individuals aged 18 or older, diagnosed with, or suspected to have pPDPH via self-help groups on Facebook. Participants completed a structured questionnaire covering diagnosis, symptoms, and the ability to work. For assessing headache related disability, and mental health, they filled in the Henry Ford Hospital Headache Disability Inventory (HDI) and the Depression Anxiety Stress Scale-21 (DASS-21).

RESULTS: A total of 179 participants (83.2% female, mean age 39.7 years) completed the survey. PPDPH had been present for one year or more in 74.3%, and 44.1% were unable to be in an upright position for more than one hour per day without having to lie down or sit down. Headaches were extremely severe or severe in 18% and 34%, respectively. According to the HDI, 31.8% of participants had mild, 25.7% moderate, and 42.5% severe disability. DASS-21 revealed substantial mental health challenges with depression, anxiety and stress experienced by 83%, 98%, and 88% of the respondents. The ability to work was limited considerably: 27.9% were unable to work, 59.8% worked part-time, 1.1% changed their job because of pPDPH, and only 11.2% were able to work full-time in their previous job. Despite treatment, the patients’ condition had deteriorated in 32.4% and remained unchanged in 27.9%.

CONCLUSIONS: This study stresses the burden of pPDPH in terms of substantial disability, limited quality of life, mental health concerns, and significant impact on the ability to work. The study highlights the long-term impact of pPDPH on individuals, emphasizing the need for timely diagnosis and effective treatment. It underscores the complexity of managing pPDPH and calls for further research into its long-term effects on patient health and HRQoL.

PMID: 38658862
DOI: 10.1186/s10194-024-01765-8

AUTHORS: Wolf K, Volz F, Lützen N, Mast H, Reisert M, Rahal AE, Fung C, Shah MJ, Beck J, Urbach H.

CITATION: J Neurol (2024). https://doi.org/10.1007/s00415-024-12365-6

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BACKGROUND AND OBJECTIVE: Spontaneous intracranial hypotension (SIH) is an underdiagnosed disease. To depict the accurate diagnosis can be demanding; especially the detection of CSF–venous fistulas poses many challenges. Potential dynamic biomarkers have been identified through non-invasive phase-contrast MRI in a limited subset of SIH patients with evidence of spinal longitudinal extradural collection. This study aimed to explore these biomarkers related to spinal cord motion and CSF velocities in a broader SIH cohort.

METHODS: A retrospective, monocentric pooled-data analysis was conducted of patients suspected to suffer from SIH who underwent phase-contrast MRI for spinal cord and CSF velocity measurements at segment C2/C3 referred to a tertiary center between February 2022 and June 2023. Velocity ranges (mm/s), total displacement (mm), and further derivatives were assessed and compared to data from the database of 70 healthy controls.

RESULTS: In 117 patients, a leak was located (54% ventral leak, 20% lateral leak, 20% CSF–venous fistulas, 6% sacral leaks). SIH patients showed larger spinal cord and CSF velocities than healthy controls: e.g., velocity range 7.6 ± 3 mm/s vs. 5.6 ± 1.4 mm/s, 56 ± 21 mm/s vs. 42 ± 10 mm/s, p < 0.001, respectively. Patients with lateral leaks and CSF–venous fistulas exhibited an exceptionally heightened level of spinal cord motion (e.g., velocity range 8.4 ± 3.3 mm/s; 8.2 ± 3.1 mm/s vs. 5.6 ± 1.4 mm/s, p < 0.001, respectively).

CONCLUSIONS: Phase-contrast MRI might become a valuable tool for SIH diagnosis, especially in patients with CSF–venous fistulas without evidence of spinal extradural fluid collection.

PMID: 38643444
DOI: 10.1007/s00415-024-12365-6

AUTHORS: Wouter I. Schievink, Marcel M. Maya, Angelique Sao-Mai S. Tay, Peyton L. Nisson, Jay Acharya, Rachelle B. Taché and Miriam Nuño

CITATION: American Journal of Neuroradiology, March 2024. DOI: https://doi.org/10.3174/ajnr.A8165

BACKGROUND AND PURPOSE: Spontaneous spinal CSF leaks typically cause orthostatic headache, but their detection may require specialized and invasive spinal imaging. We undertook a study to determine the value of simple optic nerve sheath MR imaging measurements in predicting the likelihood of finding a CSF-venous fistula, a type of leak that cannot be detected with routine spine MR imaging or CT myelography, among patients with orthostatic headache and normal conventional brain and spine imaging findings.

MATERIALS AND METHODS: This cohort study included a consecutive group of patients with orthostatic headache and normal conventional brain and spine imaging findings who underwent digital subtraction myelography under general anesthesia to look for spinal CSF-venous fistulas.

RESULTS: The study group consisted of 93 patients (71 women and 22 men; mean age, 47.5 years; range, 17–84 years). Digital subtraction myelography demonstrated a CSF-venous fistula in 15 patients. The mean age of these 8 women and 7 men was 56 years (range, 23–83 years). The mean optic nerve sheath diameter was 4.0 mm, and the mean perioptic subarachnoid space was 0.5 mm in patients with a CSF-venous fistula compared with 4.9 and 1.2 mm, respectively, in patients without a fistula (P < .001). Optimal cutoff values were found at 4.4 mm for optic nerve sheath diameter and 1.0 mm for the perioptic subarachnoid space. Fistulas were detected in about 50% of patients with optic nerve sheath diameter or perioptic subarachnoid space measurements below these cutoff values compared with <2% of patients with optic nerve sheath diameter or perioptic subarachnoid space measurements above these cutoff values. Following surgical ligation of the fistula, optic nerve sheath diameter increased from 4.0 to 5.3 mm and the perioptic subarachnoid space increased from 0.5 to 1.2 mm (P < .001).

CONCLUSIONS: Concerns about a spinal CSF leak should not be dismissed in patients with orthostatic headache when conventional imaging findings are normal, and simple optic nerve sheath MR imaging measurements can help decide if more imaging needs to be performed in this patient population.

DOI: https://doi.org/10.3174/ajnr.A8165

AUTHORS: Parikh, S.K.

CITATION: Current Pain and Headache Reports. 2024 Mar 2. doi: 10.1007/s11916-024-01231-9. Online ahead of print.

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PURPOSE OF THIS REVIEW: Rebound intracranial hypertension (RIH) is a post-procedural treatment complication in patients with spontaneous intracranial hypotension (SIH) characterized by transient high-pressure headache symptoms. This article reviews the epidemiology, clinical features, risk factors, and treatment options for RIH.

RECENT FINDINGS: This article discusses how changes in underlying venous pressure and craniospinal elastance can explain symptoms of RIH, idiopathic intracranial hypertension (IIH), and SIH.

SUMMARY: The pathophysiology of RIH provides a clue for how high and low intracranial pressure disorders, such as IIH and SIH, are connected on a shared spectrum.

PMID: 38430310
DOI: 10.1007/s11916-024-01231-9

AUTHORS: Carroll I, Callen AL

CITATION: Headache. 2024; 00: 1-4. Feb 22. doi:10.1111/head.14677

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ARTICLE HIGHLIGHTS:

The last decade has seen a significant improvement in the understanding of spinal cerebrospinal fluid (CSF) leaks and the resulting syndrome of spontaneous intracranial hypotension (SIH). For the reader of Headache and those caring for patients with chronic refractory headaches, three novel concepts are emerging from accumulating data published here and elsewhere: (1) the majority of people with an imaging-proven CSF leak have normal opening pressure; (2) CSF–venous fistulas (CVFs) are a major, rather than rare, cause of SIH; and (3) there is a persistent headache syndrome that occurs at an alarmingly high frequency after unintended dural punctures during epidurals done for analgesia in the obstetric setting.

…In light of these papers, the pre-2019 literature on SIH needs to be critically reappraised. For example, reports that MRI of the spine is 90% sensitive for detecting CSF leaks, largely based on its correlation with non-decubitus CT myelography, should now be understood to mislead more than inform. Such studies evaluated the performance of MRI for detecting CSF leaks by using conventional CT myelography as a gold standard for establishing the presence or absence of epidural fluid collections, but this is an intellectual framework now clearly undermined by CVF, in which no epidural collection is present.

…Another important emerging trend in the field of spinal CSF leaks is the growing understanding that after an unintended dural puncture (such as a dural puncture occurring during a labor epidural), a significant number of patients will report new, or worsened, headaches that persist for years. … These data suggest that for some accidentally punctured patients, the large-bore, cutting tip Tuohy needle intended to facilitate threading of an epidural catheter outside the dura may form a uniquely devastating puncture when advanced unintentionally through the dura.

…In summary, SIH remains a condition that eludes detection, humbles the clinician, and remains the great deceiver, but the headache community is increasingly catching on to its tricks. The incredible advances made in the knowledge of CSF leaks over the past decade are inspiring, and we look forward to the future, where undoubtedly new discoveries await.

PMID: 38385703
DOI: 10.1111/head.14677

AUTHORS: Volz F, El Rahal A, Fung C, Shah M, Lützen N, Urbach H, Beck J, Wolf K

CITATION: Journal of Neurology. 2024 Feb 26. doi: 10.1007/s00415-024-12242-2

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OBJECTIVE: Microsurgical sealing of spinal cerebrospinal fluid (CSF) leaks is a viable treatment option in spontaneous intracranial hypotension (SIH). Several factors may influence the outcome, with symptom duration probably the most modifiable variable.

METHODS: Patients with closure of spinal CSF leaks between September 2020 and March 2023 and a follow-up period of 6 months were included in this retrospective single-center study. Pre- and postoperative scores for impact of headaches (Headache Impact Test, HIT-6) and quality of life (QoL, EQ-5D-5L) were systematically collected. Multiple regression modelling and subgroup analyses for different symptom durations and comorbidities were performed for these outcomes.

RESULTS: One hundred patients (61% female, median age 43.5 years) were included. Six months postoperatively, there was significant improvement in headache impact (HIT-6: 66 (IQR 62-69) to 52 (IQR 40-61, p < 0.001) and QoL (EQ-5D-5L VAS: 40 (IQR 30-60) to 79 (IQR 60-90); EQ-5D-5L Index: 0.67 (IQR 0.35-0.8) to 0.91 (IQR 0.8-0.94, p < 0.001, respectively). Subgroup analysis for a symptom duration above (74%) and below 90 days (26%) and comorbidity, as well as multiple regression analysis, revealed a trend in favor of early treatment and lower comorbidity. However, even after a prolonged symptom duration, improvements were significant.

CONCLUSION: As patients with shorter symptom duration show a trend for a better outcome, our results promote a timely diagnosis and treatment in SIH patients. However, a significant postoperative improvement can still be expected even after a prolonged symptom duration.

PMID: 38409537
DOI: 10.1007/s00415-024-12242-2

AUTHORS: Shahriar Faghani, Mana Moassefi, Ajay A. Madhavan, Ian T. Mark, Jared T. Verdoorn, Bradley J. Erickson, John C. Benson

CITATION: American Journal of Neuroradiology. Feb 2024, DOI: 10.3174/ajnr.A8173

BACKGROUND AND PURPOSE: Spontaneous intracranial hypotension is an increasingly recognized condition. Spontaneous intracranial hypotension is caused by a CSF leak, which is commonly related to a CSF-venous fistula. In patients with spontaneous intracranial hypotension, multiple intracranial abnormalities can be observed on brain MR imaging, including dural enhancement, “brain sag,” and pituitary engorgement. This study seeks to create a deep learning model for the accurate diagnosis of CSF-venous fistulas via brain MR imaging.

MATERIALS AND METHODS: A review of patients with clinically suspected spontaneous intracranial hypotension who underwent digital subtraction myelogram imaging preceded by brain MR imaging was performed. The patients were categorized as having a definite CSF-venous fistula, no fistula, or indeterminate findings on a digital subtraction myelogram. The data set was split into 5 folds at the patient level and stratified by label. A 5-fold cross-validation was then used to evaluate the reliability of the model. The predictive value of the model to identify patients with a CSF leak was assessed by using the area under the receiver operating characteristic curve for each validation fold.

RESULTS: There were 129 patients included in this study. The median age was 54 years, and 66 (51.2%) had a CSF-venous fistula. In discriminating between positive and negative cases for CSF-venous fistulas, the classifier demonstrated an average area under the receiver operating characteristic curve of 0.8668 with a standard deviation of 0.0254 across the folds.

CONCLUSIONS: This study developed a deep learning model that can predict the presence of a spinal CSF-venous fistula based on brain MR imaging in patients with suspected spontaneous intracranial hypotension. However, further model refinement and external validation are necessary before clinical adoption. This research highlights the substantial potential of deep learning in diagnosing CSF-venous fistulas by using brain MR imaging.

PMID: 38423747
DOI: 10.3174/ajnr.A8173

AUTHORS: Jeremy D. Schmahmann, MD, and Wouter I. Schievink, MD

CITATION: Neurology Clinical Practice, epub ahead of print (April 2024); https://doi.org/10.1212/CPJ.0000000000200261

BACKGROUND AND OBJECTIVE: Spontaneous intracranial hypotension (SIH) from CSF leak commonly produces headache. It also may produce sagging brain syndrome (SBS), often with neurocognitive symptoms indistinguishable from behavioral-variant frontotemporal dementia (bvFTD). The authors describe a new clinical sign that appears to be pathognomonic of SBS.

MATERIALS AND METHODS: We reviewed medical records and brain imaging in patients seen at our 2 centers who presented with SIH, SBS, and bvFTD symptoms.

RESULTS: There were 51 patients (12 women, 39 men) with mean age 55.5 years (range, 26–70 years). MRI showed severe brain sagging in all. Thirteen patients displayed repetitive flexion with breath-holding at the time of clinical presentation. Five patients had repetitive flexion with breath-holding, which resolved before presenting for evaluation. Thus, 35.3% (18) of 51 patients with SBS displayed seemingly compulsive repetitive flexion with breath-holding.

DISCUSSION: Compulsive repetitive flexion with breath-holding appears to be pathognomonic of SBS, deserving the acronym CoRFBiS (compulsive repetitive flexion with breath-holding in SBS). CoRFBiS should alert the clinician to SBS with SIH as the proximate cause of the clinical constellation, rather than bvFTD.

DOI: 10.1212/CPJ.0000000000200261 

AUTHORS: Andrew L. Callen, Mo Fakhri, Vincent M. Timpone, Ashesh A. Thaker, William P. Dillon and Vinil N. Shah

CITATION: American Journal of Neuroradiology, January 2024, 45 (1) 100-104; DOI: 10.3174/ajnr.A8078

BACKGROUND AND PURPOSE: CSF-venous fistula can be diagnosed with dynamic decubitus CT myelography. This study aimed to analyze the temporal characteristics of CSF-venous fistula visualization on multiphase decubitus CT myelography.

MATERIALS AND METHODS: A retrospective, multisite study was conducted on patients diagnosed with CSF-venous fistula at 2 institutions between June 2017 and February 2023. Both institutions perform decubitus CT myelography with imaging immediately following injection and usually with at least 1 delayed scan. The conspicuity of CSF-venous fistula was assessed on each phase of imaging.

RESULTS: Forty-eight patients with CSF-venous fistula were analyzed. CSF-venous fistulas were better visualized on the early pass in 25/48 cases (52.1%), the delayed pass in 6/48 cases (12.5%) and were seen equally on both passes in 15/48 cases (31.3%). Of 25 cases in which the CSF-venous fistula was better visualized on the early pass, 21/25 (84%) fistulas were still at least partially visible on a delayed pass. Of 6 cases in which the CSF-venous fistula was better visualized on a delayed pass, 4/6 (67%) were partially visible on the earlier pass. Six of 48 (12.5%) CSF-venous fistulas were visible only on a single pass. Of these, 4/6 (66.7%) were seen only on the first pass, and 2/6 (33.3%) were seen only on a delayed pass. One fistula was found with one pass only, and one fistula was discovered upon contralateral decubitus imaging without a dedicated second injection.

CONCLUSIONS: A dynamic decubitus CT myelography imaging protocol that includes an early and delayed phase, likely increases the sensitivity for CSF-venous fistula detection. Further studies are needed to ascertain the optimal timing and technique for CSF-venous fistula visualization on dynamic decubitus CT myelography and its impact on patient outcomes.

PMID: 38123910
DOI: 10.3174/ajnr.A8078

AUTHORS: Fides R. Schwartz, MD, Peter G. Kranz, MD, Michael D. Malinzak, MD, David N. Cox, PhD, Francesco Ria, PhD, Cindy McCabe, MA, Brian Harrawood, MA, Linda G. Leithe, MD, Ehsan Samei, PhD, and Timothy J. Amrhein, MD

CITATION: American Journal of Roentgenology January 31 2024, https://doi.org/10.2214/AJR.23.30673

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BACKGROUND: CSF-venous fistulas (CVFs) are an increasingly recognized cause of spontaneous intracranial hypotension (SIH) that are often diminutive in size and exceedingly difficult to detect by conventional imaging.

OBJECTIVE: This study’s objective was to compare EID-CT myelography and PCD-CT myelography in terms of image quality and diagnostic performance for detecting CVFs in patients with SIH.

METHODS: This retrospective study included 38 patients (15 men, 23 women; mean age, 55±10 years) with SIH who underwent both clinically indicated EID-CT myelography (slice thickness, 0.625 mm) and PCD-CT myelography (slice thickness, 0.2 mm; performed in ultrahigh-resolution mode) to assess for CSF leak. Three blinded radiologists reviewed examinations in random order, assessing image noise, discernibility of spinal nerve root sleeves, and overall image quality using 0-100 scales (100=highest quality), and recording locations of CVFs. Definite CVFs were defined as CVFs described in CT myelography reports using unequivocal language and showing attenuation >70 HU.

RESULTS: For all readers, PCD-CT myelography, in comparison with EID-CT myelography, showed higher image noise (reader 1: 69±19 vs 38±15; reader 2: 59±9 vs 49±13; reader 3: 57±13 vs 43±15), higher nerve root sleeve discernibility (reader 1: 84±19 vs 30±14; reader 2: 84±19 vs 70±19; reader 3: 60±13 vs 52±12), and higher overall image quality (reader 1: 84±21 vs 40±15; reader 2: 81±10 vs 72±20; reader 3: 58±11 vs 53±11) (all p<.05). Eleven patients had a definite CVF. Sensitivity and specificity for detection of definite CVF for EID-CT myelography and PCD-CT myelography for reader 1 were 45% and 96% versus 64% and 85; for reader 2 were 36% and 100% versus 55% and 96%; and for reader 3 were 45% and 100% versus 55% and 93%. For all readers, PCD-CT myelography, in comparison with EID-CT myelography, showed significantly higher sensitivity (all p<.05), without significant difference in specificity (all p>.05).

CONCLUSION: In comparison with EID-CT myelography, PCD-CT myelography yielded significantly improved image quality with significantly higher sensitivity for CVFs without significant loss of specificity.

CLINICAL IMPACT: The findings support a potential role of PCD-CT myelography in facilitating earlier diagnosis and targeted treatment of SIH, avoiding high morbidity during potentially prolonged diagnostic workups.

PMID: 38294163
DOI: 10.2214/AJR.23.30673

AUTHORS: Thien J. Huynh, Donna Parizadeh, Ahmed K. Ahmed, Christopher T. Gandia, Hal C. Davison, John V. Murray, Ian T. Mark, Ajay A. Madhavan, Darya Shlapak, Todd D. Rozen, Waleed Brinjikji, Prasanna Vibhute, Vivek Gupta, Kacie Brewer and Olga Fermo

CITATION: American Journal of Neuroradiology January 2024, 45 (1) 105-112; DOI: https://doi.org/10.3174/ajnr.A8082

BACKGROUND AND PURPOSE: CSF-venous fistulas (CVFs) associated with spontaneous intracranial hypotension (SIH) may have a transient appearance, relative to contrast arrival, which may influence the diagnostic performance of lateral decubitus CT myelography (CTM). We developed a dynamic CTM protocol using real-time bolus-tracking (dCTM-BT) to improve the temporal resolution and standardize the timing of CTM acquisitions post-intrathecal contrast administration. The purpose of our study was to evaluate the feasibility of the dCTM-BT technique and evaluate its diagnostic yield for CVF detection, stratified by brain MRI SIH findings.

MATERIALS AND METHODS: Patients with suspected SIH without extradural fluid collection on spine MRI who underwent dCTM-BT were retrospectively reviewed. CT bolus monitoring was performed at the upper thoracic level. Following the visualization of dense intrathecal contrast, at least 3 CTM acquisitions of the spine were obtained and reviewed by 2 neuroradiologists. The Bern SIH score was calculated on the brain MRI. The diagnostic yield for CVF detection was evaluated, stratified by Bern score categories and a receiver operating characteristic (ROC) analysis.

RESULTS: Out of 48 patients, 23 (48%) had a CVF on dCTM-BT, located at T1–5 (n = 4), T6–12 (n = 18), L1 (n = 1), with 70% on the right. CVF was identified in 22/22 (100%) of patients who had a high Bern score, 1/7 (14%) of those who had an intermediate score, and 0/19 (0%) of those who had a low score. The area under the ROC curve was 0.99 (95% CI, 0.98–1.00). The optimal cutoff was a Bern score of ≥5 (96% sensitivity, 100% specificity).

CONCLUSIONS: dCTM-BT is feasible and has excellent diagnostic performance for CVF identification/localization. The Bern score is strongly associated with CVF detection and may help inform who will benefit from dCTM-BT.

PMID: 38164531
DOI: 10.3174/ajnr.A8082

AUTHORS: Zayat R, Huynh TJ, Fermo O

CITATION: Journal of Neuro Interventional Surgery, doi: 10.1136/jnis-2023-021053

BACKGROUND: The majority of patients with spontaneous intracranial hypotension (SIH) are symptomatic. Some patients are discovered incidentally. The proportion of asymptomatic SIH has never been defined. This article reports our institution’s rate of asymptomatic cases among all of our patients with high/intermediate Bern scores on brain MRI, etiology of leak in asymptomatic cases, complications of asymptomatic leaks, and evolution of imaging before and after treatment.

METHODS: We retrospectively analyzed data from the Cerebrospinal Fluid (CSF) Dynamics clinic spanning September 2020 to July 2023. Bern score was calculated from all available brain MRIs in patients with confirmed leaks. Patients with iatrogenic leaks or no brain MRI were excluded. The charts of asymptomatic patients were reviewed to obtain MRI indications, SIH progression, complications, leak type, and treatment outcomes.

RESULTS: Some 8.6% (7/81) patients with high/intermediate Bern scores were asymptomatic at the time of imaging. Two patients declined myelography. Four of seven asymptomatic patients were found to have CSF-venous fistulas and underwent embolization with radiographic improvement. Complications of asymptomatic leaks in this population included subdural hematoma and superficial siderosis.

CONCLUSIONS: Asymptomatic but clearly present spinal CSF leaks were not uncommon in our group. These results highlight the possibility of a presymptomatic phase in patients with CSF leaks. In our sample, myelography was readily positive for etiology of the leak, and leaks promptly responded to targeted treatment.

doi: 10.1136/jnis-2023-021053

AUTHORS: Zayat R, Fermo OP, Huynh TJ.

CITATION: Neurol Neurochir Pol. 2024 Jan 31. doi: 10.5603/pjnns.97522. Epub ahead of print.

AIM OF THE STUDY: This study presents cases of recurrent cerebrospinal fluid-venous fistulas (CVFs) de novo at a different spinal level following successful treatment of initial CVFs. The aim was to highlight this rarely described phenomenon and report the clinical and imaging features after initial treatment, providing insights into the dynamics of recurrent CVFs.

CLINICAL RATIONALE FOR THE STUDY: Understanding the course of CVFs post-treatment is crucial for optimising patient management, especially when symptoms persist or recur.

MATERIAL AND METHODS: We performed a retrospective chart review of all patients with recurrent CVFs at a different level after treatment of their initial CVF at our institution. Clinical and imaging records were reviewed and summarised, including Bern score features on brain magnetic resonance imaging (MRI) before and after treatment.

RESULTS: Four patients with five recurrent CVFs were identified. Recurrent or persistent symptoms encouraged subsequent brain MRI scans, which revealed different outcomes: i.e. persistence, or improvement, or complete resolution of abnormal findings. Initial positive responses included improvement of the pachymeningeal enhancement and venous sinus distension. These improvements were reversed when recurrent symptoms arose, which was also correlated with changes in the Bern score.

CONCLUSIONS AND CLINICAL IMPLICATIONS: Recognizing the factors of CVF recurrence is crucial for comprehensive management. This study underlines the significance of repeated evaluation of persistent or recurring symptoms of CSF leak after treatment for CVFs.

PMID: 38294430
DOI: 10.5603/pjnns.97522