Infratentorial Superficial Siderosis and Spontaneous Intracranial Hypotension.

OBJECTIVE: Spontaneous spinal cerebrospinal fluid (CSF) leaks cause intracranial hypotension (SIH) and also may cause infratentorial superficial siderosis (iSS) but the rate of development among different CSF leak types and outcome of treatment are not known. We determined the time interval from SIH onset to iSS and the outcome of treatment. METHODS: A total of 1,589 patients with SIH underwent neuroimaging and iSS was detected in 57 (23 men and 34 women, mean age = 41.3 years [3.6%]). We examined the type of underlying CSF leak by various imaging modalities. Percutaneous and surgical procedures were used to treat the CSF leaks. RESULTS: The iSS was detected in 46 (10.3%) of 447 patients with ventral CSF leaks, in 2 (3.9%) of 51 patients with dural ectasia, in 5 (2.6%) of 194 patients with CSF-venous fistulas, in 4 (0.9%) of 457 patients with simple meningeal diverticula, and in none of the 101 patients with lateral CSF leaks or the 339 patients with leaks of indeterminate origin (p < 0.001). The estimated median latency period from SIH onset to iSS was 126 months. Ventral CSF leaks could not be eliminated with percutaneous procedures in any patient and surgical repair was associated with low risk (<5%) and resulted in resolution of the CSF leak in all patients in whom the exact site of the CSF leak could be determined. Other types of CSF leak were treated with percutaneous or surgical procedures. INTERPRETATION: The iSS can develop in most types of spinal CSF leak, including CSF-venous fistulas, but mainly in chronic ventral CSF leaks, which require surgical repair. ANN NEUROL 2023;93:64-75.

Spontaneous intracranial hypotension mimicking iatrogenic spinal cerebrospinal fluid leaks.

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

Pediatric post-dural puncture headache and paraplegia.

A cerebrospinal fluid (CSF) leak developed in a 14-year-old girl and a 12-year-old boy following a diagnostic lumbar puncture. Two days and sixteen years later, respectively, paraplegia developed due to a functional disorder. Imaging revealed an extensive extradural CSF collection in both patients and digital subtraction myelography was required to pinpoint the exact site of a ventral dural puncture hole where the lumbar spinal needle had gone "through and through" the dural sac. The CSF leak was complicated by cortical vein thrombosis in one patient. Both patients underwent uneventful surgical repair of the ventral dural puncture hole with prompt resolution of the paraplegia. Iatrogenic ventral CSF leaks may become exceptionally long standing and may be complicated by paraplegia on a functional basis both in the acute and chronic phases.

Incidence of spontaneous intracranial hypotension in a community: Beverly Hills, California, 2006-2020.

BACKGROUND: Spontaneous intracranial hypotension is diagnosed with an increasing frequency, but epidemiologic data are scarce. The aim of this study was to determine the incidence rate of spontaneous intracranial hypotension in a defined population. METHODS: Using a prospectively maintained registry, all patients with spontaneous intracranial hypotension residing in Beverly Hills, California, evaluated at our Medical Center between 2006 and 2020 were identified in this population-based incidence study. Our Medical Center is a quaternary referral center for spontaneous intracranial hypotension and is located within 1.5 miles from downtown Beverly Hills. RESULTS: A total of 19 patients with spontaneous intracranial hypotension were identified. There were 12 women and seven men with a mean age of 54.5 years (range, 28 to 88 years). The average annual incidence rate for all ages was 3.7 per 100,000 population (95% confidence interval [CI]: 2.0 to 5.3), 4.3 per 100,000 for women (95% CI, 1.9 to 6.7) and 2.9 per 100,000 population for men (95% CI, 0.8 to 5.1). CONCLUSION: This study, for the first time, provides incidence rates for spontaneous intracranial hypotension in a defined population.

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

OBJECTIVE: 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. BACKGROUND: Spontaneous spinal CSF leaks cause orthostatic headaches but their detection may require sophisticated spinal imaging techniques. METHODS: 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. RESULTS: The mean age of the 60 consecutive patients (46 women and 14 men) was 46 years (range, 13-83 years), who had been suffering from orthostatic headaches between 1 and 180 months (mean, 43 months). 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 50 years (range, 41-59 years). 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 3 months postoperatively. CONCLUSION: 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.