Spinal Cerebrospinal Fluid Leak Research Articles

68Ga]Ga-DOTA PET for validation of spinal cerebrospinal fluid leakage in spontaneous intracranial hypotension

68Ga]Ga-DOTA PET for validation of spinal cerebrospinal fluid leakage in spontaneous intracranial hypotension

Incidence of Spinal CSF Leakage on CT Myelography in Patients with Nontraumatic Intracranial Subdural Hematoma.

The aim of the present study was to demonstrate the incidence of spinal cerebrospinal fluid (CSF) leaks in patients with nontraumatic intracranial subdural hematoma (SDH) and determine clinical parameters favoring such leaks. This retrospective study was approved by the institutional review board. Patients diagnosed with nontraumatic intracranial SDH who underwent computed tomography (CT) myelography between January 2012 and March 2018 were selected. 60 patients (male: female, 39:21; age range, 20–82 years) were enrolled and divided into CSF leak-positive and CSF leak-negative groups according to CT myelography data. Clinical findings were statistically compared between the two groups. Spinal CSF leak was observed in 80% (48/60) of patients, and it was significantly associated with an age of <69 years (p = 0.006). However, patients aged ≥69 years also had a tendency to exhibit spontaneous intracranial hypotension (SIH)-induced nontraumatic intracranial SDH (60.87%; 14/23). Therefore, CT myelography is recommended to be performed for the evaluation of possible SIH in patients with nontraumatic intracranial SDH, particularly those aged <69 years. Patients aged ≥69 years are also good candidates for CT myelography because SIH tends to occur even in this age group.

Heavily T2-Weighted Magnetic Resonance Myelography as a Safe Cerebrospinal Fluid Leakage Detection Modality for Nontraumatic Subdural Hematoma.

ObjectiveNontraumatic subdural hematoma (SDH) is a common disease, and spinal cerebrospinal fluid (CSF) leakage is a possible etiology of unknown significance, which is commonly investigated by several invasive studies. This study demonstrates that heavily T2-weighted magnetic resonance myelography (HT2W-MRM) is a safe and clinically effective imaging modality for detecting CSF leakage in patients with nontraumatic SDH. MethodsAll patients who underwent HT2W-MRM for nontraumatic SDH workup at our institution were searched and enrolled in this study. Several parameters were measured and analyzed, including patient demographic data, initial modified Rankin Scale (mRS) score upon presentation, SDH bilaterality, hematoma thickness upon presentation, CSF leakage sites, treatment modalities, followup hematoma thickness, and follow-up mRS score. ResultsForty patients were identified, of which 22 (55.0%) had CSF leakage at various spinal locations. Five patients (12.5%) showed no change in mRS score, whereas the remaining (87.5%) showed decreases in follow-up mRS scores. In terms of the overall hematoma thickness, four patients (10.0%) showed increased thickness, two (5.0%) showed no change, 32 (80.0%) showed decreased thickness, and two (5.0%) did not undergo follow-up imaging for hematoma thickness measurement. ConclusionHT2W-MRM is not only safe but also clinically effective as a primary diagnostic imaging modality to investigate CSF leakage in patients with nontraumatic SDH. Moreover, this study suggests that CSF leakage is a common etiology for nontraumatic SDH, which warrants changes in the diagnosis and treatment strategies.

Risk factors for nonresponsive hydration in patients with spinal cerebrospinal fluid leakage

BackgroundSpinal cerebrospinal fluid (CSF) leakage is frequently encountered clinically after lumbar puncture or spontaneous events. Although some patients recover without treatment or after intensive hydration, some require an epidural blood patch (EBP). The risks of nonresponsive hydration remain unknown. Therefore, we identified the risk factors for patients with spinal CSF leakage nonresponsive to hydration.MethodsWe retrospectively reviewed patients diagnosed with spinal CSF leakage between January 2010 and March 2021. Clinical data, including patient age, sex, etiology, and radiological indications in magnetic resonance imaging, were compared between patients who were responsive and non-responsive to hydration.ResultsOf the 74 patients with spinal CSF leakage, 25 were responsive to hydration and 49 required EBP. Patients who were nonresponsive to hydration were older (39.27 vs. 34.32 years, P = 0.01), had a higher percentage of spontaneous intracranial hypotension (93.88% vs. 68.00%, P = 0.005), had more spinal CSF leakage (12.04 vs. 8.04, P = 0.01), and had a higher percentage of dural sinus engorgement (81.63% vs. 60.00%, P = 0.044). Spontaneous intracranial hypotension (odds ratio [OR]: 4.63; 95% confidence interval [CI]: 1.00-21.38) and having ≥9 spinal CSF leakages (OR: 3.29; 95% CI: 1.08-10.01), as indicated by magnetic resonance myelography, are considered risk factors for noneffective hydration.ConclusionsPatients with spinal CSF leakage who have spontaneous intracranial hypotension and those with ≥9 spinal CSF leakages are considered at risk for noneffective hydration. EBP should be considered early in these patients.

Outcome of Thoracic Column Antedisplacement and Fusion in Treatment of Thoracic Myelopathy Caused by Ossification of Posterior Longitudinal Ligament: A Case Series Study.

Up to date, surgical outcome of multilevel thoracic ossification of posterior longitudinal ligament (T-OPLL) with high canal occupation ratio is less satisfactory. To explore the result of thoracic column antedisplacement and fusion (TCAF) in treatment of multilevel T-OPLL with high canal occupation ratio. A total of 5 patients who underwent TCAF procedure for T-OPLL were retrospectively reviewed. Parameters including extent of OPLL, thickness of the maximal OPLL (max-OPLL), maximal canal occupying ratio (max-COR) of OPLL, effective canal diameter (ECD) at the max-OPLL level, antedisplacement distance of thoracic columns, ASIA grades, Japanese Orthopedic Association (JOA) scores, and complications were collected and analyzed at preoperation and the last follow-up. All patients (5 F, mean age 61.0 yr, mean follow-up 18.0 months) underwent TCAF successfully and no spinal cord injury or cerebrospinal fluid leakage occurred. The mean extent of OPLL was 2.8 vertebral bodies. The mean preoperative thickness of the max-OPLL was 5.9 mm. The average antedisplacement distance of thoracic columns was 5.6 mm. The mean ECD was improved from 6.5 mm to 10.9 mm, and the max-COR was improved from 50.7% to 7.1% at last follow-up. Two patients showed improvement in ASIA grades and JOA scores were significantly improved from 5.6 points to 10.4 points at final follow-up. The overall therapeutic results of 1 patient were classified into good and 4 into fair at last follow-up. TCAF may be a safe and effective procedure in treatment of multilevel T-OPLL with high canal occupation ratio.

Diagnostic Yield of Intrathecal Gadolinium MR Myelography for CSF Leak Localization.

Intrathecal gadolinium magnetic resonance (MR) myelography can be used to localize various types of spinal cerebrospinal fluid (CSF) leaks; however, its diagnostic yield is not well known. We sought to determine the diagnostic yield of MR myelography in patients with spontaneous intracranial hypotension. Aretrospective review was performed on all patients who had undergone intrathecal gadolinium MR myelography at our institution from 2002 to 2020 for suspected spinal CSF leak. The MR myelography images were reviewed for the presence or absence of aspinal CSF leak site. Images were also evaluated for the presence an extradural fluid collection. A total of 97patients were included in the final cohort. The average age was 52.6years; 67.0% were female, 4 patients underwent 2 examinations each, yielding atotal of 101 MR myelograms. The source of aspinal CSF leak was localized in 14patients. The diagnostic yield for CSF leak localization on intrathecal gadolinium MR myelography was 14/101 (13.9%) per GdM examination and 14/97 (14.4%) per patient. Among the subset of patients without extradural fluid collections, the yield was 15.7% per examination. All detected leaks were either CSF-venous fistulas or distal nerve root sleeve tears. Intrathecal gadolinium MR myelography is capable of localizing CSF-venous fistulas and distal nerve root sleeve tears; however, our data show that it has alimited diagnostic yield. We suggest that other modalities may be abetter first step before attempting intrathecal gadolinium MR myelography.

Outcome after surgical treatment of cerebrospinal fluid leaks in spontaneous intracranial hypotension\u2014a matter of time

ObjectiveSpinal cerebrospinal fluid (CSF) leaks cause spontaneous intracranial hypotension (SIH). Microsurgery can sufficiently seal spinal CSF leaks. Yet, some patients suffer from residual symptoms. Aim of the study was to assess predictors for favorable outcome after surgical treatment of SIH.MethodsWe included consecutive patients with SIH treated surgically from January 2013 to May 2020. Subjects were surveyed by a questionnaire. Primary outcome was resolution of symptoms as rated by the patient. Secondary outcome was postoperative headache intensity on the numeric rating scale (NRS). Association between variables and outcome was assessed using univariate and multivariate regression. A cut-off value for continuous variables was calculated by a ROC analysis.ResultsSixty-nine out of 86 patients (80.2%) returned the questionnaire and were analyzed. Mean age was 46.7 years and 68.1% were female. A significant association with the primary and secondary outcome was found only for preoperative symptom duration (p = 0.001 and p < 0.001), whereby a shorter symptom duration was associated with a better outcome. Symptom duration remained a significant predictor in a multivariate model (p = 0.013). Neither sex, age, type of pathology, lumbar opening pressure, nor initial presentation were associated with the primary outcome. ROC analysis yielded treatment within 12 weeks as a cut-off for better outcome.ConclusionShorter duration of preoperative symptoms is the most powerful predictor of favorable outcome after surgical treatment of SIH. While an initial attempt of conservative treatment is justified, we advocate early definitive treatment within 12 weeks in case of persisting symptoms.

In Reply to the Letter to the Editor Regarding “Spontaneous Spinal Cerebrospinal Fluid Leak: Review and Management Algorithm”

Expandable vertebrectomy devices are a key technology that has facilitated the adoption of minimally invasive approaches to spine oncology surgery. However, advanced technology still requires proper attention to surgical fundamentals. Here we illustrate a cage of a misplaced expandable vertebrectomy device causing esophageal perforation. Examination of the postoperative radiographs suggests that haptic feedback from the expandable technology may have given the false impression of bony engagement. This case highlights the need for proper mortise work and complete visualization of the segments to be instrumented even during minimally invasive surgery.

Cerebrospinal Fluid-Venous Fistulas: A Systematic Review and Examination of Individual Patient Data.

Spontaneous intracranial hypotension (SIH) is usually caused by a spinal cerebrospinal fluid (CSF) leak. CSF-venous fistula is an underdiagnosed cause of spinal CSF leak, as it is challenging to identify on myelography. To review existing literature to summarize common presentations, diagnostic imaging modalities, and current treatment strategies for CSF-venous fistulas. We conducted a systematic review using PubMed, Embase, Scopus, and Web of Science databases to identify studies discussing CSF-venous fistulas. Titles and abstracts were screened. Studies meeting prespecified inclusion criteria were reviewed in full. Of 180 articles identified, 16 articles met inclusion criteria. Individual patient data was acquired from 7 studies reporting on 18 patients. CSF-venous fistula most frequently presented as positional headache. Digital subtraction myelography provided greatest detection of CSF-venous fistula in the lateral decubitus position and detected CSF-venous fistula in all individual patient cases. Dynamic computed tomography (CT) myelogram enabled detection and differentiation of CSF-venous fistulas from low-flow epidural leaks. The majority of fistulas were in the thoracic spine and slightly more common on the right. Epidural blood patch (EBP) provided temporary or no relief in all individual patients. Resolution or improvement of clinical symptoms and radiologic normalization were observed in all surgically treated patients. Although rare, CSF-venous fistula is an important cause of spinal CSF leak contributing to SIH. Dynamic CT myelogram and digital subtraction myelography, particularly in the lateral decubitus position, are the most accurate and effective diagnostic imaging modalities. EBPs often provide only transient relief, while surgical management is preferred.

Microsurgical anatomy and treatment of dural defects in spontaneous spinal cerebrospinal fluid leaks.

Spontaneous spinal CSF leaks are caused by abnormalities of the spinal dura mater. Although most cases are treated conservatively or with an epidural blood patch, some intractable cases require neurosurgical treatment. However, previous reports are limited to a small number of cases. Preoperative detection and localization of spinal dural defects are difficult, and surgical repair of these defects is technically challenging. The authors present the anatomical characteristics of dural defects and surgical techniques in treating spontaneous CSF leaks. Among the consecutive patients who were diagnosed with spontaneous CSF leaks at the authors' institution between 2010 and 2020, those who required neurosurgical treatment were included in the study. All patients' clinical information, radiological studies, surgical notes, and outcomes were reviewed retrospectively. Outcomes of two different procedures in repairing dural defects were compared. Among 77 patients diagnosed with spontaneous CSF leaks, 21 patients (15 men; mean age 57 years) underwent neurosurgery. Dural defects were detected by FIESTA MRI in 7 patients, by CT myelography in 12, by digital subtraction myelography in 1, and by dynamic CT myelography in 1. The spinal levels of the defects were localized at the cervicothoracic junction in 16 patients (76%) and thoracolumbar junction in 4 (19%). Intraoperative findings revealed that the dural defects were small, circumscribed longitudinal slits located at the ventral aspect of the dura mater. The median dural defect size was 5 × 2 mm. The presence of dural defects at the thoracolumbar junction was associated with manifestation of an altered mental status, which was an unusual manifestation of CSF leaks (p = 0.003). Eight patients were treated via the posterior transdural approach with watertight primary sutures of the ventral defects, and 13 were treated with muscle or fat grafting. Regardless of the two different procedures, postoperative MRI showed either complete disappearance or significant reduction of the extradural CSF collection. No patient experienced postoperative neurological deficits. Clinical symptoms improved or stabilized in 20 patients with a median follow-up of 12 months. Dural defects in spontaneous CSF leaks were small, circumscribed longitudinal slits located ventral to the spinal cord at either the cervicothoracic or thoracolumbar junction. Muscle/fat grafting may be an alternative treatment to watertight primary sutures of ventral dural defects with a good outcome.

A systematic review and meta-analysis of factors affecting the outcome of the epidural blood patching in spontaneous intracranial hypotension.

Spontaneous intracranial hypotension (SIH) is an often misdiagnosed condition resulting from non-iatrogenic cerebrospinal fluid (CSF) hypovolemia, typically secondary to spinal CSF leakage. Patients commonly present with posture-related headache, nausea, and vomiting. Following failure of conservative measures, epidural blood patching (EBP) is the most commonly performed intervention for spinal CSF leaks. The authors performed a systematic review and meta-analysis of existing literature to evaluate the role of different factors possibly affecting the efficacy of the EBP procedure. In accordance with the PRISMA guidelines, PubMed/Medline and SCOPUS databases were searched. Six eligible articles were retrieved. Five hundred patients were treated for SIH with EBP, of which 300 reported good response defined as complete remission of symptoms within 48 h after the first EBP requiring no further invasive treatment. Among the factors available for meta-analysis, none was found to be statistically significant in affecting the efficacy of the EBP procedure. A largely symmetrical funnel plot is reported for all the variables evaluated, indicating that publication bias did not play a significant role in the observed effects. The current knowledge about SIH and the EBP is scarce. The existing literature is contradictory and insufficient to aid in clinical practice. More studies are needed to draw significant conclusions that may help in the identification of patients at higher risk of EBP failure, who may benefit from different approaches.

Spontaneous spinal cerebrospinal fluid-venous fistulas in patients with orthostatic headaches and normal conventional brain and spine imaging.

To determine the occurrence of cerebrospinal fluid (CSF)-venous fistulas, a type of spinal CSF leak that cannot be detected with routine computerized tomography myelography, among patients with orthostatic headaches but normal brain and spine magnetic resonance imaging. Spontaneous spinal CSF leaks cause orthostatic headaches but their detection may require sophisticated spinal imaging techniques. A prospective cohort study of patients with orthostatic headaches and normal brain and conventional spine imaging who underwent digital subtraction myelography (DSM) to look for CSF-venous fistulas, between May 2018 and May 2020, at a quaternary referral center for spontaneous intracranial hypotension. The mean age of the 60 consecutive patients (46 women and 14 men) was 46years (range, 13-83years), who had been suffering from orthostatic headaches between 1 and 180months (mean, 43months). DSM demonstrated a spinal CSF-venous fistula in 6 (10.0%; 95% confidence interval [CI]: 3.8-20.5%) of the 60 patients. The mean age of these five women and one man was 50years (range, 41-59years). Spinal CSF-venous fistulas were identified in 6 (19.4%; 95% CI: 7.5-37.5%) of 31 patients with spinal meningeal diverticula but in none (0%; 95% CI: 0-11.9%) of the 29 patients without spinal meningeal diverticula (p=0.024). All CSF-venous fistulas were located in the thoracic spine. All patients underwent uneventful surgical ligation of the fistula. Complete and sustained resolution of symptoms was obtained in five patients, while in one patient, partial recurrence of symptoms was noted 3months postoperatively. Concerns about a spinal CSF leak should not be dismissed in patients suffering from orthostatic headaches when conventional imaging turns out to be normal, even though the yield of identifying a CSF-venous fistula is low.

Intravenous enhanced 3D FLAIR imaging to identify CSF leaks in spontaneous intracranial hypotension: Comparison with MR myelography

PurposeTo evaluate the clinical utility of intravenous gadolinium-enhanced heavily T2-weighted 3D fluid-attenuated inversion recovery (HT2-FLAIR) imaging for identifying spinal cerebrospinal fluid (CSF) leaks in patients with spontaneous intracranial hypotension (SIH). MethodsPatients with SIH underwent MR myelography and post-contrast HT2-FLAIR imaging after an intravenous gadolinium injection. Two types of CSF leaks (epidural fluid collection and CSF leaks around the nerve root sleeve) at each vertebral level were compared between the 2 sequences. The total numbers of CSF leaks and vertebral levels involved were recorded for the whole spine. The sequence that was superior for the overall visualization of epidural and paraspinal fluid collection was then selected. ResultsNine patients with SIH were included in the present study. HT2-FLAIR imaging was equivalent or superior to MR myelography at each level for detecting the 2 types of CSF leaks. In the 2 types of CSF leaks, the total numbers of CSF leaks and levels involved were higher on HT2-FLAIR images than on MR myelography, while no significant difference was observed for CSF leaks around the nerve root sleeve. In all 9 patients, HT2-FLAIR imaging was superior to MR myelography for the overall visualization of epidural and paraspinal fluid collection. ConclusionIntravenous gadolinium-enhanced HT2-FLAIR imaging was superior to MR myelography for the visualization of CSF leaks in patients with SIH. This method can be useful for identifying spinal CSF leaks.

Radiological society of North America: 106th annual meeting, November 29 to December 5, 2020

Radiological society of North America: 106th annual meeting, November 29 to December 5, 2020

Spinal dural leaks in patients with infratentorial superficial siderosis of the central nervous system-Refinement of a diagnostic algorithm.

Superficial siderosis of the central nervous system is a sporadic finding in magnetic resonance imaging, resulting from recurrent bleedings into the subarachnoid space. This study aimed to determine the frequency of spinal dural cerebrospinal fluid (CSF) leaks amongst patients with a symmetric infratentorial siderosis pattern. In all, 97,733 magnetic resonance images performed between 2007 and 2018 in our neurocenter were screened by a keyword search for "hemosiderosis" and "superficial siderosis." Siderosis patterns on brain imaging were classified according to a previously published algorithm. Potential causative intracranial bleeding events were also assessed. Patients with a symmetric infratentorial siderosis pattern but without causative intracranial bleeding events in history were prospectively evaluated for spinal pathologies. Forty-two patients with isolated supratentorial siderosis, 30 with symmetric infratentorial siderosis and 21 with limited (non-symmetric) infratentorial siderosis were identified. Amyloid angiopathy and subarachnoid hemorrhage were causes for isolated supratentorial siderosis. In all four patients with a symmetric infratentorial siderosis pattern but without a causative intracranial bleeding event in history, spinal dural abnormalities were detected. Dural leaks were searched for in patients with symmetric infratentorial siderosis and a history of intracranial bleeding event without known bleeding etiology, considering that spinal dural CSF leaks themselves may also cause intracranial hemorrhage, for example by inducing venous thrombosis due to low CSF pressure. Thereby, one additional spinal dural leak was detected. Persisting spinal dural CSF leaks can frequently be identified in patients with a symmetric infratentorial siderosis pattern. Diagnostic workup in these cases should include magnetic resonance imaging of the whole spine.

Role of Conventional Dynamic Myelography for Detection of High-Flow Cerebrospinal Fluid Leaks

BackgroundSpinal imaging is essential to identify and localize cerebrospinal fluid (CSF) leaks in spontaneous intracranial hypotension (SIH) patients when targeted treatment is necessary.PurposeProvide an in-depth presentation of the conventional dynamic myelography (CDM) technique for localizing spinal CSF leaks in SIH patients.Material and MethodsConsecutive SIH patients with a CSF leak confirmed on CDM and postmyelography computed tomography (CT) investigated at our institution between 2013 and 2019 were retrospectively analyzed. Intraoperative reports were reviewed to confirm the accuracy of CDM.ResultsIn total, 62 patients (mean age 45 years) were included; 48 with a ventral dural tear, 12 with a meningeal diverticulum, and in 2 patients positive for spinal longitudinal extradural CSF collection the site remained unclear. The leak was identified during the first and the second CDM in 43 and 17 patients, respectively. The use of CDM correctly identified the site of the CSF leak in all but one patient undergoing surgical closure (45/46, 98%). The mean fluoroscopy time was 7.8 min (range 1.8–14.4 min) with a radiation dose for a single examination of 310 mGy (range 28–1237 mGy).ConclusionThe CDM procedure has a high accuracy for spinal CSF leak localization including dural tears and spinal nerve diverticula. It is the technique with the highest temporal resolution, is robust to breathing artifacts, allows great flexibility regarding patient positioning, compares favorably to other dynamic examinations with respect to the radiation dose and does not require general anesthesia. For CSF venous fistulas, however, other dynamic examinations, such as digital subtraction myelography, seem more appropriate.

Brain volume changes in spontaneous intracranial hypotension: Revisiting the Monro-Kellie doctrine.

In the application of the Monro-Kellie doctrine in spontaneous intracranial hypotension, the brain tissue volume is generally considered as a fixed constant. Traditionally, cerebral venous dilation is thought to compensate for decreased cerebrospinal fluid. However, whether brain tissue volume is invariable has not yet been explored. The objective of this study is to evaluate whether brain tissue volume is fixed or variable in spontaneous intracranial hypotension patients using automatic quantitative methods. This retrospective and longitudinal study analyzed spontaneous intracranial hypotension patients between 1 January 2007 and 31 July 2015. Voxel-based morphometry was used to examine brain volume changes during and after the resolution of spontaneous intracranial hypotension. Brain structure volume was analyzed using Statistical Parametric Mapping version 12 and FMRIB Software Library v6.0. Post-treatment neuroimages were used as surrogate baseline measures. Forty-four patients with spontaneous intracranial hypotension were analyzed (mean [standard deviation] age, 37.8 [8.5] years; 32 female and 12 male). The whole brain tissue volume was decreased during spontaneous intracranial hypotension compared to follow-up (1180.3 [103.5] mL vs. 1190.4 [93.1] mL, difference: -10.1 mL [95% confidence interval: -18.4 to -1.8 mL], p = 0.019). In addition, ventricular cerebrospinal fluid volume was decreased during spontaneous intracranial hypotension compared to follow-up (15.8 [6.1] mL vs. 18.9 [6.9] mL, difference: -3.2 mL [95% confidence interval: -4.5 to -1.8 mL], p < 0.001). Longer anterior epidural cerebrospinal fluid collections, as measured by number of vertebral segments, were associated with greater reduction of ventricular cerebrospinal fluid volume (Pearson's r = -0.32, p = 0.036). The current study found the brain tissue volume and ventricular cerebrospinal fluid are decreased in spontaneous intracranial hypotension patients. The change in ventricular cerebrospinal fluid volume, but not brain tissue volume change, was associated with the severity of spinal cerebrospinal fluid leakage. These results challenge the assumption that brain tissue volume is a fixed constant.

Syrinx Secondary to Chiari-like Tonsillar Herniation in Spontaneous Intracranial Hypotension

Syrinx development in patients with spontaneous intracranial hypotension (SIH) has rarely been described. To better understand this entity, we compared the clinical and radiographic findings in a series of patients with SIH and acquired Chiari-like tonsillar herniation with and without syrinx formation. Six patients with syrinx in the setting of SIH and Chiari-like tonsillar herniation were retrospectively identified. The clinical and radiographic findings and outcomes were compared with those from a control group of patients with SIH and Chiari-like tonsillar herniation without syrinx. The patients with SIH and syrinx had had a higher opening pressure than had the control group (mean, 14.0 cm H2O vs. 7.4 cm H2O; P= 0.02) and a higher body mass index (mean, 33 kg/m2 vs. 26 kg/m2; P= 0.01). The patients with syrinx had had an average obex displacement of 3.7 ± 2.2 mm below the plane of the foramen magnum compared with a position of 1.9 ± 3.1 mm above the plane of the foramen magnum in the control group (P= 0.004). The mean tonsillar descent was 12.7 ± 4.7 mm below the foramen magnum in those with syrinx compared with 5.9 ± 2.5 in the control group (P= 0.009). The clinical symptoms had improved in 83.3% of the patients with syrinx and 75% of the control patients after spinal cerebrospinal fluid leak closure. Three patients (50%) also had radiographic syrinx reduction. Our results have shown that SIH can be an underrecognized cause of syrinx with key differences in body habitus and obex displacement compared with SIH without syrinx. In patients with tonsillar herniation into the foramen magnum associated with syrinx, the presence of SIH should be considered to avoid unnecessary foramen magnum decompression, even in those with a normal opening pressure.

Spontaneous Intracranial Hypotension.

Spontaneous intracranial hypotension (SIH) is an underdiagnosed disease. Its incidence is estimated at 5 per 100 000 persons per year. This review is based on a selective literature search in PubMed covering the years 2000-2019, as well as on the authors' personal experience. The diagnostic and therapeutic methods discussed here are supported by level 4 evidence. SIH is caused by spinal leakage of cerebrospinal fluid (CSF) out of ventral dural tears or nerve root diverticula, or, in 2-5% of cases, through a fistula leading directly into the periradicular veins (CSF-venous fistula). In half of all patients, no CSF leak is demonstrable. A low CSF opening pressure on lumbar puncture is present in only one-third of patients; imaging studies are thus needed to confirm and localize a spinal CSF leak. Half of all patients in whom myelographic computed tomography (CT) reveals contrast medium reaching the epidural space have ventral dural tears, which tend to be located at upper thoracic spinal levels. Epidural blood patches applied under fluoroscopic or CT guidance can seal the CSF leak in 30-70% of patients, but 90% of patients with ventral dural tears will need operative closure. Some patients who have no visible epidural contrast medium on CT presumably do not have SIH, while others do, in fact, have a CSF leak from a diverticulum or a CSF-venous fistula and will need to have the site of the leak demonstrated with the aid of further studies, such as dynamic (subtraction) myelography in the lateral decubitus position. The management of patients with SIH calls for complementary imaging studies to demonstrate the causative spinal CSF leak. Often, successful treatment requires surgical closure of the leak. In view of the sparse evidence available to date, controlled studies should be performed.

Spinal cerebrospinal fluid leak in the context of pars interarticularis fracture

BackgroundSpinal cerebrospinal fluid (CSF) leak can lead to intracranial hypotension and is an important differential diagnosis to consider in patients with sudden-onset chronic daily headaches. Pars interarticularis (PI) fracture is a potential rare cause of suspected spinal CSF leak.MethodsThis is a retrospective case series of 6 patients with suspected spinal CSF leak evaluated between January 2016 and September 2019. All patients received a magnetic resonance imaging (MRI) of the brain with and without gadolinium, MRI whole spine and full spine computed tomography (CT) myelogram. Targeted epidural patches with fibrin sealant were performed. Treatment response at return visit (3 months post-patch) was documented.ResultsSix patients (4 females, 2 males) were diagnosed with a suspected spinal CSF leak and PI fracture. Mean age at the time of headache onset was 39 years old, and a range from 32 to 50 years old. Mean time to targeted epidural patches with fibrin sealant was 4.5 years. All 6 patients had PI fractures identified on CT myelogram and received targeted epidural patches with fibrin sealant at the site of the PI fracture. All patients had significant improvement in their headache intensity.ConclusionOur study highlights: 1) the importance of PI fracture as a possible culprit of suspected spinal CSF leak in patients with intracranial hypotension; 2) the added benefit of CT imaging for detecting bony abnormalities such as fractures in patients with intracranial hypotension; and 3) the successful treatment of suspected spinal CSF leak when targeting the fracture site.