Surgical closure of spinal cerebrospinal fluid leaks improves symptoms in patients with superficial siderosis.

BACKGROUND AND PURPOSE: Spinal cerebrospinal fluid (CSF) leaks may cause a myriad of symptoms, most common being orthostatic headache. In addition, ventral spinal CSF leaks are a possible etiology of superficial siderosis (SS), a rare condition characterized by hemosiderin deposits in the central nervous system (CNS). The classical presentation of SS involves ataxia, bilateral hearing loss, and myelopathy. Unfortunately, treatment options are scarce. This study was undertaken to evaluate whether microsurgical closure of CSF leaks can prevent further clinical deterioration or improve symptoms of SS. METHODS: This cohort study was conducted using data from a prospectively maintained database in two large spontaneous intracranial hypotension (SIH) referral centers in Germany and Switzerland of patients who meet the modified International Classification of Headache Disorders, 3rd edition criteria for SIH. Patients with spinal CSF leaks were screened for the presence of idiopathic infratentorial symmetric SS of the CNS. RESULTS: Twelve patients were included. The median latency between the onset of orthostatic headaches and symptoms attributed to SS was 9.5 years. After surgical closure of the underlying spinal CSF leak, symptoms attributed to SS improved in seven patients and remained stable in three. Patients who presented within 1 year after the onset of SS symptoms improved, but those who presented in 8-12 years did not improve. We could show a significant association between patients with spinal longitudinal extrathecal collections and SS. CONCLUSIONS: Long-standing untreated ventral spinal CSF leaks can lead to SS of the CNS, and microsurgical sealing of spinal CSF leaks might stop progression and improve symptoms in patients with SS in a time-dependent manner.

Clinical value of neuroimaging indicators of intracranial hypertension in patients with cerebral venous thrombosis.

PURPOSE: Intracranial hypertension (IH) frequently complicates cerebral venous thrombosis (CVT). Distinct neuroimaging findings are associated with IH, yet their discriminative power, reversibility and factors favoring normalization in prospective CVT patients are unknown. We determined test performance measures of neuroimaging signs in acute CVT patients, their longitudinal change under anticoagulation, association with IH at baseline and with recanalization at follow-up. METHODS: We included 26 consecutive acute CVT patients and 26 healthy controls. Patients were classified as having IH based on CSF pressure > 25 cmH2O and/or papilledema on ophthalmological examination or ocular MRI. We assessed optic nerve sheath diameter (ONSD), optic nerve tortuousity, bulbar flattening, lateral and IVth ventricle size, pituitary configuration at baseline and follow-up, and their association with IH and venous recanalization. RESULTS: 46% of CVT patients had IH. ONSD enlargement > 5.8 mm, optic nerve tortuousity and pituitary grade ≥ III had highest sensitivity, ocular bulb flattening and pituitary grade ≥ III highest specificity for IH. Only ONSD reliably discriminated IH at baseline. Recanalization was significantly associated with regressive ONSD and pituitary grade. Other neuroimaging signs tended to regress with recanalization. After treatment, 184.9 ± 44.7 days after diagnosis, bulbar flattening resolved, whereas compared with controls ONSD enlargement (p < 0.001) and partially empty sella (p = 0.017), among other indicators, persisted. CONCLUSION: ONSD and pituitary grading have a high diagnostic value in diagnosing and monitoring CVT-associated IH. Given their limited sensitivity during early CVT and potentially persistent alterations following IH, neuroimaging indicators can neither replace CSF pressure measurement in diagnosing IH, nor determine the duration of anticoagulation.

Recovery and long-term outcome after neurosurgical closure of spinal CSF leaks in patients with spontaneous intracranial hypotension.

INTRODUCTION: Spontaneous intracranial hypotension due to a spinal cerebrospinal fluid leak causes orthostatic headaches and impacts quality of life. Successful closure rates are often reported, whereas data on long-term outcome are still scarce. METHODS: Between April 2020 and December 2022 surgically treated patients completed the Headache Impact Test-6 prior to surgery and at 14 days, three months, six months, and 12 months postoperatively. In addition to the Headache Impact Test-6 score, we extracted data related to orthostatic symptoms. RESULTS: Eighty patients were included. Median Headache Impact Test-6 score preoperatively was 65 (IQR 61-69), indicating severe and disabling impact of headaches. At three months headache impact significantly improved to 49 (IQR 44-58) (p < 0.001) and remained stable up to 12 months (48, IQR 40-56), indicating little to no impact of headaches on quality of life. The need to lie down "always" or "very often" was reduced from 79% to 23% three months postoperatively (p < 0.001). CONCLUSIONS: Surgical closure of spinal CSF leaks significantly improves the impact of headaches in the long term. At least three months should be expected for recovery. Despite permanent closure of the CSF-leak, a quarter of patients still have relevant long-term impairment, indicating the need for further research on its cause and possible treatment.

The "hyperdense basivertebral vein" sign: another marker of a CSF-venous fistula.

CSF-venous fistulas - initially described in 2014 - are a significant cause of spontaneous intracranial hypotension. Dynamic lateral decubitus digital subtraction and/or CT myelography typically show a hyperdense paraspinal vein. In case of a central drainage toward the internal vertebral venous plexus, it is the "hyperdense basivertebral vein" which should be searched for carefully.

Glioblastoma evolving within 10 days following unremarkable computer tomography of the brain: a case report.

Glioblastoma multiforme might develop radiologically within a few days following unremarkable CT scan of the brain. Glioblastoma multiforme is the most frequent primary brain tumor. Initial presentations are diverse, including headache, seizures and transient or persistent neurological deficits. Cerebral imaging followed by histological examination of a tissue specimen is the mainstay of diagnosis. We report the case of a 79-year-old female patient whose computer tomography (CT) of the brain was unremarkable at first clinical presentation with a transient hemiparesis of the right side, but revealed a cerebral space-occupying lesion ultimately diagnosed as glioblastoma only 10 days later. According to our case presentation glioblastoma might develop radiologically within a few days following unremarkable CT scan of the brain. Since clinical manifestation with a transient ischemic attack (TIA)-like episode was preceding CT manifestation, this case indicates, that a magnetic resonance imaging (MRI) should be routinely performed in all patients presenting with TIA.

[Magnetic Resonance Imaging of the Optic Pathway]. / Magnetresonanztomografie der Sehbahn.

This overview is especially intended for practitioners in ophthalmology. It focuses on how to handle diseases affecting the optic pathway with MRI in general and in particular. Several tables accompany this article, in order to illustrate the different MRI scanning protocols, properties of frequently used MRI sequences, as well as common pathologies to be found in the optic pathway. With the help of exemplary cases, the application and interpretation of MRI imaging will be shown. There is a tremendous variety of diseases influencing the optic pathway - which is why this article does not intend to give a complete representation of this medical issue, but rather focuses on giving hands-on guidance (through multiple tables) for daily routine. Moreover, the article also addresses the issue of retained gadolinium in the brain.

Case report: low-titre anti-Yo reactivity in a female patient with psychotic syndrome and frontoparieto-cerebellar atrophy.

BACKGROUND: Autoimmune and inflammatory mechanisms in psychotic disorders have attracted increasing scientific attention in recent years. In this regard, we performed routine cerebrospinal fluid (CSF) basic diagnostics and CSF/serum analyses for antibodies directed against neuronal intracellular and surface antigens in psychotic patients. In this context, the patient presented in this paper was diagnosed. CASE PRESENTATION: We present the case of a 20-year-old female patient with a first episode of a drug-induced psychotic syndrome but without neurological deficits. Further investigations showed a reproducible low-titre positive anti-Yo reactivity in the CSF and serum with two independent immunoblot assays. Magnetic resonance imaging showed frontoparietal and cerebellar atrophy. On [(18)F]fluorodeoxyglucose positron emission tomography, a mild cerebellar hypometabolism was found. No underlying tumor was detected. CONCLUSION: Despite the presence of anti-Yo reactivity, the diagnostic criteria for a paraneoplastic neurological syndrome were not fulfilled. Previously published data indicate the possible association between low-titer antibodies against intracellular localized, onconeural antigens, and psychotic disorders. Large prospective studies that investigate the prevalence and clinical significance of antibodies against intracellular onconeural antigens in psychiatry are needed.

Immune response to Propionibacterium acnes in patients with sarcoidosis--in vivo and in vitro.

BACKGROUND: Propionibacterium acnes was found in lungs and lymph nodes of patients with sarcoidosis and may induce hypersensitivity type granuloma formation. Data regarding the immune response to P. acnes of European sarcoid patients are scarce. METHODS: We assessed the total IgG and IgA amount and specific antibodies to P. acnes and to Staphylococcus aureus, serving as a control, in BAL fluid of 64 patients with sarcoidosis and of 21 healthy volunteers. In a subcohort of sarcoid patients and controls, TNF-α and GM-CSF production of BAL cells stimulated with heat-killed P. acnes were measured. RESULTS: In sarcoid patients, the total IgG and IgA levels in BAL fluid were significantly elevated compared to healthy volunteers. IgG and IgA titres against P. acnes and S. aureus were increased in sarcoid patients, yet based on the total amount of antibodies, only antibodies directed against P. acnes were relatively and significantly increased. Furthermore, BAL cells of sarcoid patients produced significantly more TNF-α and GM-CSF upon stimulation with heat-killed P. acnes compared to controls. CONCLUSIONS: Patients with sarcoidosis had elevated levels of specific antibodies against P. acnes which suggest contact with this bacterium in the past. Furthermore, BAL cells of sarcoid patients produced inflammatory cytokines (TNF-α and GM-CSF) upon stimulation with P. acnes indicating potential involvement of this pathogen in the pathogenesis of sarcoidosis in some patients.

Cerebrospinal fluid-venous fistula visualisation by intrathecal pressurization: A technical note and illustrative case.

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.

Don't delay, but don't despair: symptom duration, comorbidity and outcome after closure of spinal cerebrospinal fluid leaks.

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.

Spontaneous intracranial hypotension - a spinal disease. / Spontane intrakranielle Hypotension ­ eine spinale Erkrankung.

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.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.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. · SIH is an underdiagnosed condition with a wide range of possible symptoms.. · The first diagnostic step using MRI provides indications of the presence of SIH.. · The second diagnostic step using (dynamic) myelography can identify the CSF leak.. · Collaboration with a CSF center is advisable for further diagnosis and treatment.. · Prompt detection and treatment of SIH improves the outcome.. · Zander C, Wolf K, El Rahal A et al. Spontaneous intracranial hypotension - a spinal disease. Fortschr Röntgenstr 2024; DOI 10.1055/a-2318-8994.

Non-invasive biomarkers for spontaneous intracranial hypotension (SIH) through phase-contrast MRI.

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). CONCLUSION: 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.

Impact of Spinal CSF Leaks on Quality of Life and Mental Health and Long-Term Reversal by Surgical Closure.

Background and Objectives: Spontaneous intracranial hypotension (SIH) caused by a spinal CSF leak is a multisymptom syndrome, which can dramatically affect physical and mental health. However, systematic data on health-related quality of life (HRQoL) and mental health are scarce. We hypothesized that surgical treatment leads to significant and sustained improvements in HRQoL and mental health in patients with SIH. Methods: In this single-center cohort study, we prospectively collected HRQoL and mental health data in patients undergoing surgical closure of a spinal CSF leak from September 2020 to November 2022. EuroQoL (EQ-5D-5L), including the health state index (EQ-Index) and the visual analog scale (EQ-VAS), measured HRQoL. The 21-item version of the Depression Anxiety Stress Scales (DASS-21) measured symptoms of mental health. Follow-ups were performed 3 and 6 months postoperatively. Primary outcome was the change in EQ-Index, EQ-VAS, and DASS-21 subscales. Secondary outcome was the impact of baseline depression symptoms on HRQoL outcomes following surgery. Results: Seventy-four patients were included. EQ-VAS improved from 40 (interquartile range [IQR] 30-60) preoperatively to 70 (IQR 55-85) at 3 months and to 72 (IQR 60-88) at 6 months postoperatively (p < 0.001, respectively). EQ-Index increased from 0.683 (IQR 0.374-0.799) to 0.877 (0.740-0.943) at 3 months and to 0.907 (0.780-0.956) at 6 months postoperatively (p < 0.001, respectively). Depression, anxiety, and stress significantly improved after surgery. Preoperative depressive symptoms did not affect the HRQoL outcome. Discussion: The severe impact of a spinal CSF leak on HRQoL and mental health significantly improved after closure of the leak. Higher levels of depressive symptoms do not predict worse outcomes and should not discourage invasive treatment. Further systematic evaluation of outcomes, with special regard to quality of life, is needed, as it allows a comparison of symptom burden between SIH and more familiar diseases as well as a comparison of different treatment modalities in future studies.

Distinct Pattern of Membrane Formation With Spinal Cerebrospinal Fluid Leaks in Spontaneous Intracranial Hypotension.

BACKGROUND AND OBJECTIVES: To systematically describe pertinent, intraoperative anatomic findings encountered when approaching spinal cerebrospinal fluid (CSF) leaks and CSF-venous fistulas in spontaneous intracranial hypotension (SIH). METHODS: In a retrospective study, we included surgically treated patients suffering from SIH at our institution from April 2018 to March 2022. Anatomic, intraoperative data were extracted from operative notes and supplemented with data from surgical videos and images. Prominent anatomic features were compared among different types of CSF leaks. RESULTS: The study cohort consists of 120 patients with a mean age of 45.2 years. We found four distinct patterns of spinal membranes specifically associated with different types of CSF leaks: (i) thick, dorsal membranes, which were hypervascular and may mimic the dura (pseudodura); (ii) thin, lateral membranes encapsulating a ventral epidural CSF compartment (confining the spinal longitudinal extradural CSF collection); (iii) ventral membranes constituting a transdural funnel-like CSF channel; and (iv) lateral membranes forming spinal cysts/meningeal diverticulae associated with lateral CSF leaks. The latter three types resemble a layer of arachnoid herniated through the dural defect. CONCLUSION: We describe four distinct spinal (neo-)membranes in association with spinal CSF leaks. Formation of these membranes, or emergence by herniation of arachnoid through a dural defect, constitutes a specific pathoanatomic feature of patients with SIH and CSF leaks. Recognition of these membranes is of paramount importance for diagnosis and treatment of patients with spinal CSF leaks.

Spinal CSF Leaks: The Neuroradiologist Transforming Care.

SUMMARY: Spinal CSF leak care has considerably evolved over the past several years due to pivotal advances in its diagnosis and treatment. To the reader of the AJNR, it has been impossible to miss the exponential increase in groundbreaking research on spinal CSF leaks and spontaneous intracranial hypotension (SIH). While many clinical specialties have contributed to these successes, the neuroradiologist has been instrumental in driving this transformation due to innovations in non-invasive imaging, novel myelographic techniques, and imageguided therapies. In this editorial, we will delve into the exciting advancements in spinal CSF leak diagnosis and treatment and celebrate the vital role of the neuroradiologist at the forefront of this revolution, with particular attention to CSF leak related work published in the AJNR.ABBREVIATIONS: SIH = spontaneous intracranial hypotension; CVF = CSF-venous fistula; CTM = CT myelography; DSM = digital subtraction myelography; CB-CTM = conebeam CT myelography; PCD-CT = photon counting detector CT.

[Spontaneous intracranial hypotension]. / ABC om Spontan intrakraniell hypotension.

Spontaneous intracranial hypotension (SIH) is a disease presenting mostly with orthostatic head and neck pain due to a spontaneous cerebrospinal fluid (CSF) leak or a CSF-venous fistula in the spinal region. It demonstrates typical MRI findings with sagging of the brain causing tension of the meninges and sometimes the cranial nerves. It shares some clinical similarities with post puncture headache but differs in its pathophysiological cause, diagnosis, and treatment. Many patients remain misdiagnosed or wait too long for the correct diagnosis. The diagnostic work-up includes an MRI of the head and spine in search of typical SIH signs. Myelography and CT scans are performed to identify the location of the CSF leak or CSF-venous fistula. Treatment options may involve (1) initial conservative treatment with bed rest, caffein and fluids, (2) interventions such as epidural blood patch, fibrin patch, and embolization, or (3) surgical closure of the leak.

Prone Dynamic CT Myelography in Spontaneous Intracranial Hypotension : Diagnostic Need and Radiation Doses.

BACKGROUND AND PURPOSE: The diagnostic work-up in patients with spontaneous intracranial hypotension (SIH) and spinal longitudinal extradural CSF collection (SLEC) on magnetic resonance imaging (MRI) comprises dynamic digital subtraction myelography (dDSM) in prone position for leak detection. Dynamic computed tomography (CT) myelography (dCT-M) in prone position follows if the leak is not unequivocally located. A drawback of dCT­M is a high radiation dose. This study evaluates the diagnostic needs of dCT-M examinations and measures to reduce radiation doses. METHODS: Frequency, leak sites, length and number of spiral acquisitions, DLP and effective doses of dCT­M were retrospectively recorded in patients with ventral dural tears. RESULTS: Of 42 patients with ventral dural tears, 8 underwent 11 dCT­M when the leak was not unequivocally shown on digital subtraction myelography. The median number of spiral acquisitions was 4 (range 3-7) and the mean effective radiation dose 30.6 mSv (range 13.1-62.16 mSv) mSv. Five of eight leaks were located in the upper thoracic spine (range C7/Th1-Th2/3). Bolus tracking of intrathecal contrast agent in dCT­M was used to limit the number and length of spiral acquisitions. DISCUSSION: A dCT­M in prone position to localize a ventral dural tear is needed in every fifth patient with a SLEC on MRI. It is typically needed when the leak is located in the upper thoracic spine and when patients have broad shoulders. Measures to reduce the radiation dose include bolus tracking or to repeat the DSM with adjusted positioning of patient.

Sacral Dural Tears as a Cause of Spontaneous Intracranial Hypotension.

PURPOSE: Dural tears at the level of the cervical, thoracic, and lumbar spine cause spontaneous intracranial hypotension (SIH) in patients with a spinal longitudinal extradural CSF collection (SLEC); however, sacral dural tears have rarely been reported so far. This study focuses on sacral dural tears as a cause of SIH. METHODS: Retrospective data from SIH patients with confirmed sacral dural tears studied between October 2020 and November 2022 were analyzed with respect to demographic, clinical and imaging features. Digital subtraction myelography (DSM) and lumbar epidural blood patch (EBP) were modified by placing the patient in reversed Trendelenburg position. RESULTS: Of the SIH patients, 9 (all women; mean age, 38.5 years; mean body mass index, BMI, 22.9) out of 149 had a sacral dural leak (6%) that occurred spontaneously in 7/9, while 2/9 were likely associated with minor trauma. None had a sacral fracture. The mean SIH score was 6.8. All patients showed SLEC on heavily T2-weighted MR myelography (T2-MRM), 4/9 exclusively sacral and 5/9 with partial or complete involvement of the remaining spine. 4/9 had none, but 5/9 had meningeal sacral cysts, 2/5 had large cysts/ectasia. Confirmation of the sacral origin of the leak was provided in 4/9 by T2-MRM, in 2/9 by DSM and 3/9 by CT myelography (CTM) whereas 0/9 revealed the exact site of leak within the sacrum. CONCLUSION: Sacral dural tears should be considered as a possible cause for SIH. It is concluded to implement T2-MRM covering the entire sacrum in the standard MRI protocol and propose EBP in the reverse Trendelenburg position as a therapeutic approach.

Minimally invasive surgery for spinal cerebrospinal fluid leaks in spontaneous intracranial hypotension.

OBJECTIVE: Spinal CSF leaks cause spontaneous intracranial hypotension (SIH). Surgical closure of spinal CSF leaks is the treatment of choice for persisting leaks. Surgical approaches vary, and there are no studies in which minimally invasive techniques were used. In this study, the authors aimed to detail the safety and feasibility of minimally invasive microsurgical sealing of spinal CSF leaks using nonexpandable tubular retractors. METHODS: Consecutive patients with SIH and a confirmed spinal CSF leak treated at a single institution between April 2019 and December 2020 were included in the study. Surgery was performed via a dorsal 2.5-cm skin incision using nonexpandable tubular retractors and a tailored interlaminar fenestration and, if needed, a transdural approach. The primary outcome was successful sealing of the dura, and the secondary outcome was the occurrence of complications. RESULTS: Fifty-eight patients, 65.5% of whom were female (median age 46 years [IQR 36-55 years]), with 38 ventral leaks, 17 lateral leaks, and 2 CSF venous fistulas were included. In 56 (96.6%) patients, the leak could be closed, and in 2 (3.4%) patients the leak was missed because of misinterpretation of the imaging studies. One of these patients underwent successful reoperation, and the other patient decided to undergo surgery at another institution. Two other patients had to undergo reoperation because of insufficient closure and a persisting leak. The rate of permanent neurological deficit was 1.7%, the revision rate for a persisting or recurring leak was 3.4%, and the overall revision rate was 10.3%. The rate of successful sealing during the primary closure attempt was 96.6% and 3.4% patients needed a secondary attempt. Clinical short-term outcome at discharge was unchanged in 14 patients and improved in 25 patients, and 19 patients had signs of rebound intracranial hypertension. CONCLUSIONS: Minimally invasive surgery with tubular retractors and a tailored interlaminar fenestration and, if needed, a transdural approach is safe and effective for the treatment of spinal CSF leaks. The authors suggest performing a minimally invasive closure of spinal CSF leaks in specialized centers.

Intraoperative Visualization of Flow in Direct Cerebrospinal Fluid-Venous Fistulas Using Intrathecal Fluorescein.

BACKGROUND: Cerebrospinal fluid-venous fistulas (CVFs) are a rare cause of spontaneous intracranial hypotension. Intraoperatively, CVFs are not readily identifiable and difficult to differentiate from normal veins. OBJECTIVE: To assess the utility of intrathecal fluorescein injection intraoperatively to visualize and identify the CVF. METHODS: We report a case series of patients treated surgically for a CVF. After surgical exposure, we injected intrathecal fluorescein (5-10 mg) through a lumbar catheter, which we placed immediately before surgery. RESULTS: Four patients with spontaneous intracranial hypotension with a suspected CVF underwent surgical ligation with adjunctive intrathecal fluorescein application. Intraoperative fluorescein injection confirmed the presence of a CVF in 3 cases. In 2 cases, we observed rapid fluorescein filling of a single epidural vein constituting the CVF. Other epidural vessels did not fill with fluorescein. In 1 case, fluorescein helped to identify a residual CVF after previous incomplete embolization. In the fourth case, no CVF was found intraoperatively. By contrast, a meningeal nerve root diverticulum was visualized, wrapped, and clipped. CONCLUSION: We demonstrate for the first time the direct intraoperative visualization of CVF using intrathecal fluorescein. CVF can be identified intraoperatively using fluorescein dye, which can be a valuable adjunct for the surgeon confronted with this disease.