Chronic Subdural Hematoma Associated with Spontaneous Intracranial Hypotension: Therapeutic Strategies and Outcomes of 55 Cases.

Spontaneous intracranial hypotension (SIH) has increasingly been recognized, and it is well known that SIH is sometimes complicated by chronic subdural hematoma (SDH). In this study, 55 cases of SIH with SDH were retrospectively analyzed, focusing on therapeutic strategies and outcomes. Of 169 SIH cases (75 males, 84 females), 55 (36 males, 19 females) were complicated by SDH. SIH was diagnosed based on clinical symptoms, neuroimaging, and/or low cerebrospinal fluid pressure. Presence of orthostatic headache and diffuse meningeal enhancement on magnetic resonance imaging were regarded as the most important criteria. Among 55 SIH with SDH cases, 13 improved with conservative treatment, 25 initially received an epidural blood patch (EBP), and 17 initially underwent irrigation of the hematomas. Of the 25 initially treated with EBP, 7 (28.0%) needed SDH surgery and 18 (72.0%) recovered fully without surgery. Of 17 SDH cases initially treated with surgery, 6 (35.7%) required no EBP therapy and the other 11 (64.3%) needed EBP and/or additional SDH operations. In the latter group, 2 cases had transient severe complications during and after the procedures. One of these 2 cases developed a hoarse voice complication. Despite this single, non-severe complication, all enrolled in this study achieved good outcomes. The present study suggests that patients initially receiving SDH surgery may need additional treatments and may occasionally have complications. If conservative treatment is insufficient, EBP should be performed prior to hematoma irrigation.