Typical features of spontaneous intracranial hypotension (SIH), including normal lumbar puncture opening pressure, nonorthostatic headache, or normal neuroimaging findings, are not a reason to exclude a SIH diagnosis, according to a systematic review and meta-analysis published online on January 4 in JAMA Neurology.
These findings show that a significant minority of patients may have normal imaging results, nonorthostatic headache, or normal lumbar punctures. Therapy with one epidural blood patch is generally successful, with large volume blood patches leading to better outcomes, noted Linda D'Antona, MD, MBBS, of the National Hospital for Neurology and Neurosurgery in London, and colleagues.
“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," they wrote.
Dr. D'Antona's group reviewed 144 papers and included an average of 53 patients with SIH per paper, culling papers from a broad range of reviews and meta-analyses from Embase, Cochrane, and PubMed/MedLine. They searched the records through to April 30, 2020.
Nausea (54 percent), orthostatic headache (92 percent), and neck pain/stiffness (43 percent) were the most common symptoms of SIH, according to the reviews. Brain MRI, which was the most sensitive diagnostic approach, found diffuse pachymeningeal enhancement in 73 percent of patients and 19 percent of patients were normal.
Spinal neuroimaging identified extradural cerebrospinal fluid in 48 percent to 76 percent of patients. And magnetic resonance myelography and digital subtraction myelography with intrathecal gadolinium had high sensitivity for identifying the exact leak site.
Moreover, lumbar puncture opening pressures were high, normal, and low in 3 percent, 32 percent, and 67 percent, respectively.
Other findings showed that a single epidural blood patch was effective in 64 percent and conservative treatment was successful in 28 percent of patients.
Small epidural blood patches were less successful than large epidural blood patches (>20 mL) (66 percent and 77 percent, respectively).
The systematic review was limited by the lack of randomized clinical trials, the lack of consistency involved in the diagnostic criteria used over the course of the past decades, and the heterogeneity of the SIH research in the existing literature, the authors noted.
“Large randomized clinical trials will be required to define the best management for SIH," the researchers concluded.
Dr. D'Antona disclosed received a research fellowship sponsored by B. Braun and is funded by a National Institute for Health Research Academic Clinical Fellowship.
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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; Epub 2021 Jan 4.