Clinical Presentation, Investigation Findings, and Treatment Outcomes of Spontaneous Intracranial Hypotension Syndrome: A Systematic Review and Meta-analysis.

Importance: Spontaneous intracranial hypotension (SIH) is a highly disabling but often misdiagnosed disorder. The best management options for patients with SIH are still uncertain. Objective: To provide an objective summary of the available evidence on the clinical presentation, investigations findings, and treatment outcomes for SIH. Data Sources: Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline-compliant systematic review and meta-analysis of the literature on SIH. Three databases were searched from inception to April 30, 2020: PubMed/MEDLINE, Embase, and Cochrane. The following search terms were used in each database: spontaneous intracranial hypotension, low CSF syndrome, low CSF pressure syndrome, low CSF volume syndrome, intracranial hypotension, low CSF pressure, low CSF volume, CSF hypovolemia, CSF hypovolaemia, spontaneous spinal CSF leak, spinal CSF leak, and CSF leak syndrome. Study Selection: Original studies in English language reporting 10 or more patients with SIH were selected by consensus. Data Extraction and Synthesis: Data on clinical presentation, investigations findings, and treatment outcomes were collected and summarized by multiple observers. Random-effect meta-analyses were used to calculate pooled estimates of means and proportions. Main Outcomes and Measures: The predetermined main outcomes were the pooled estimate proportions of symptoms of SIH, imaging findings (brain and spinal imaging), and treatment outcomes (conservative, epidural blood patches, and surgical). Results: Of 6878 articles, 144 met the selection criteria and reported on average 53 patients with SIH each (range, 10-568 patients). The most common symptoms were orthostatic headache (92% [95% CI, 87%-96%]), nausea (54% [95% CI, 46%-62%]), and neck pain/stiffness (43% [95% CI, 32%-53%]). Brain magnetic resonance imaging was the most sensitive investigation, with diffuse pachymeningeal enhancement identified in 73% (95% CI, 67%-80%) of patients. Brain magnetic resonance imaging findings were normal in 19% (95% CI, 13%-24%) of patients. Spinal neuroimaging identified extradural cerebrospinal fluid in 48% to 76% of patients. Digital subtraction myelography and magnetic resonance myelography with intrathecal gadolinium had high sensitivity in identifying the exact leak site. Lumbar puncture opening pressures were low, normal (60-200 mm H2O), and high in 67% (95% CI, 54%-80%), 32% (95% CI, 20%-44%), and 3% (95% CI, 1%-6%), respectively. Conservative treatment was effective in 28% (95% CI, 18%-37%) of patients and a single epidural blood patch was successful in 64% (95% CI, 56%-72%). Large epidural blood patches (>20 mL) had better success rates than small epidural blood patches (77% [95% CI, 63%-91%] and 66% [95% CI, 55%-77%], respectively). Conclusions and Relevance: Spontaneous intracranial hypotension should not be excluded on the basis of a nonorthostatic headache, normal neuroimaging findings, or normal lumbar puncture opening pressure. Despite the heterogeneous nature of the studies available in the literature and the lack of controlled interventional studies, this systematic review offers a comprehensive and objective summary of the evidence on SIH that could be useful in guiding clinical practice and future research.

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

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Excellent Outcomes of Large-Volume Epidural Blood Patch Using an Intravenous Catheter in 15 Consecutive Cases with Cerebrospinal Fluid Leak.

OBJECTIVE: The effects of large-volume epidural blood patch (EBP) remain unclear in patients with cerebrospinal fluid (CSF) leak. We report excellent outcomes from 15 consecutive CSF leak cases that underwent a large-volume EBP using an intravenous catheter from a single lumbar entry point, together with outcomes from 4 patients who underwent direct surgical closure or drip-and-rest therapy during the same period. METHODS: Nineteen patients with idiopathic CSF leaks were enrolled in this study since November 2011 (12 women; mean age, 43.3 ± 14.0 years). Patient demographic data, radiologic findings, symptoms, administrated therapies, complications, and clinical courses were investigated retrospectively. RESULTS: Different types of headache were observed, including typical orthostatic headache alone (n = 10), orthostatic headache with chronic subdural hematoma (CSDH) (n = 3), and posture-unrelated headache accompanied with CSDH (n = 6). Regarding treatments, in 1 case, direct surgical closure was performed. In 15 cases, large-volume EBPs were performed, and the volume of injected blood was 44.8 ± 21.6 mL. The other 3 cases were treated by simple drip infusion regardless of the drainage for CSDH. Out of 9 cases with accompanied CSDH, recurrence of subdural hematoma was completely prevented by the application of an EBP after drainage in 5 cases and without drainage in 3 cases, and by simple intravenous drip-and-rest therapy after drainage in 1 case. Among 10 patients suffering from typical orthostatic headache alone, symptoms disappeared completely in 7 cases and were relieved in 3 cases. CONCLUSIONS: We demonstrate here a perfect control of spinal CSF leaks with the administration of a large-volume EBP through an intravenous catheter.

Factors associated with the onset and persistence of post-lumbar puncture headache.

IMPORTANCE: This study assesses factors associated with the most common adverse event following lumbar puncture. OBJECTIVE: To identify factors associated with the risk, onset, and persistence of post-dural puncture headache (PDPH). DESIGN, SETTING, AND PARTICIPANTS: We performed univariate and multivariable analyses of 338 lumbar punctures in the Dominantly Inherited Alzheimer Network observational study using linear mixed models, adjusting for participant-level and family-level random effects. MAIN OUTCOMES AND MEASURES: We directly evaluated associations of 3 post-lumbar puncture outcomes (immediate postprocedural headache, PDPH at 24-hour follow-up, and PDPH receiving a therapeutic blood patch) with participant age and sex, positioning, collection method, needle size, needle insertion site, and cerebrospinal fluid (CSF) volume collected. RESULTS: The incidence of adverse events included 73 immediate postprocedural headaches (21.6%), 59 PDPHs at 24-hour follow-up (17.5%), and 15 PDPHs receiving a therapeutic blood patch (4.4%). Greater volume of CSF collected was associated with increased risk of immediate postprocedural headache, largely owing to a nonlinear increase in risk on collection of volumes above 30 mL (odds ratio, 3.73 for >30 mL and 0.98 for <17 mL). In contrast, collection of higher volumes showed a protective effect in decreasing rates of PDPH at 24-hour follow-up and rates of PDPH receiving a therapeutic blood patch (odds ratio, 0.35 per 10 mL). Although differences in needle size did not reach statistical significance, no participant in the 24G needle group received a therapeutic blood patch compared to 8 of 253 for the larger 22G needles. CONCLUSIONS AND RELEVANCE: Factors that acutely lower CSF pressure (eg, seated positioning or extracting very high volumes of CSF) may be associated with transient post-lumbar puncture headache, without increasing rates of persistent PDPH or therapeutic blood patch. Collection of up to 30 mL of CSF appears to be well tolerated and safe.

High thoracic/cervical epidural blood patch for spontaneous cerebrospinal fluid leak: a new challenge for anesthesiologists.

Spontaneous cerebral spinal fluid leakage is increasingly recognized as a cause of headache due to low intracranial pressure. The site of leakage can be identified with radionuclide cisternography, and anesthesiologists are increasingly requested to provide epidural blood patch for their management. This series of case reports demonstrates some of the issues relating to the management of this condition.