Efficacy of epidural blood patching or surgery in spontaneous intracranial hypotension: an evidence map protocol

Background: Spontaneous intracranial hypotension (SIH) is a debilitating disorder caused by non-iatrogenic spinal cerebrospinal fluid leaks. SIH is increasingly recognized as an important treatable cause of secondary headaches. Treatment involves either epidural blood patching or surgery, which have considerable differences in their adverse event rates, recovery times, and cost. The objective of this evidence map is to understand the breadth of studies that investigate SIH treatment efficacy and to identify knowledge gaps to inform future research. Methods: This review will consider experimental, observational, and systematic review studies that assess the efficacy of epidural blood patching and surgery for the treatment of patients with SIH. Individual case studies, clinical guidelines, editorials, protocols, and studies that do not assess an intervention will not be included. English language studies will be included without limitation based on the date of publication. Databases to be searched include MEDLINE® (via Ovid), EMBASE (via Elsevier), and Web of Science™ (via Clarivate). Study selection will be performed independently by two investigators with extracted data to include study type, the number of patients included, patient descriptors, intervention characteristics, and outcome measure used. Data will be presented through a narrative summary aided by tabular and graphical formats in a manner that aligns with the objective of the evidence mapping review. Discussion: The overarching goal of this evidence map is to provide an improved understanding of the breadth of studies investigating SIH treatment efficacy in the literature and to thereby identify knowledge gaps that can inform future research directions. Trial registration: OSF Registry https://osf.io/nwju7.