By Matthew S. Robbins, MD, FAAN, FAHS
Neurology Residency Program Director, Associate Professor of Neurology, Weill Cornell Medical College, New York-Presbyterian Hospital
SYNOPSIS: A systematic review of spontaneous intracranial hypotension demonstrates heterogeneity in clinical and radiographic presentations. Diagnostic studies, such as brain imaging and lumbar puncture, may be unrevealing, and the clinician may have to rely on symptom patterns alone to make a diagnosis.
SOURCE: D’Antona L, Merchan MAJ, Vassiliou A, et al. Clinical presentation, investigation findings, and treatment outcomes of spontaneous intracranial hypotension syndrome: A systematic review and meta-analysis. JAMA Neurol 2021; Jan 4:e204799. doi:10.1001/jamaneurol.2020.4799. [Online ahead of print].
In this study, D’Antona and colleagues conducted a systematic review on spontaneous intracranial hypotension. Their aim was to collect data on clinical presentations, diagnostic testing, and treatment to lead to better understanding of this often vexing and debilitating neurological disorder and to generate clinical practice recommendations.
The authors included studies featuring ≥ 10 patients, with the systematic review ultimately comprised of 144 articles, none of which were randomized controlled trials. The mean age of clinical presentation was 42.5 years, with 63% women. An orthostatic headache was the most common (92%) symptom, with holocephalic or occipital locations predominating. Nausea, vomiting, neck stiffness, and vestibulocochlear symptoms were the most common accompaniments.
Brain magnetic resonance imaging (MRI) revealed 73% with pachymeningeal enhancement, 35% with subdural collections, 43% with brain sagging, 57% with venous engorgement, and 38% with pituitary enlargement. Notably, brain MRI was unremarkable in 19%. The yield of spine imaging was heterogeneous given the low number of subjects in the studies, with the thoracic spine being the most common leak site identified in 41%. Two-thirds (67%) of patients had low opening pressure on lumbar puncture.
Twenty-eight percent of patients had symptom resolution with conservative therapy, such as bed rest and hydration. Autologous large volume epidural blood patch was more effective than lower volumes, without significant adverse effects, and a variety of surgical techniques were described with low numbers of patients in studies.
This systematic review and meta-analysis provide a comprehensive study on cerebrospinal fluid (CSF) leaks, which cause spontaneous intracranial hypotension/hypovolemia. The importance of this meta-analysis is enhanced, given the lack of large studies or randomized trials in the literature.
CSF leaks can have a variety of causes, and this study did not stratify by etiology, such as meningeal diverticulum, ventral tears from a discogenic source, or CSF-venous fistulas, which may have differing demographics, clinical presentations, and treatment responses.
In addition to an orthostatic headache, more specific headache phenotypes have been identified in spontaneous intracranial hypotension, such as exertional headache or a “second half of the day” headache, that were not addressed in this review. However, clinical pearls were reinforced by this systematic review.
Although orthostatic headache is the most common presentation, and CSF leaks feature characteristic neuroimaging findings, neither is sufficient nor necessary to make the diagnosis, with the corollary that empiric treatment with an epidural blood patch still should be considered in the absence of a more plausible diagnosis.