Subdural hematoma - Emerging treatments

Corticosteroids

Corticosteroids have been proposed as a treatment targeting inflammation and angiogenesis in chronic subdural hematomas (SDHs).[113] Expert consensus recommends against the use of corticosteroids for SDH. One small series found a benefit for corticosteroid treatment for recurrent chronic SDHs.[114] However, in one UK multicenter, randomized trial among adults with symptomatic chronic SDH (n=680), most of whom had undergone surgery to remove their hematomas during the index admission, treatment with dexamethasone resulted in fewer favorable outcomes (defined as a score of 0 to 3 on the modified Rankin scale at 6 months) and more adverse events (e.g., hyperglycemia, new-onset diabetes, new-onset psychosis, and infections) than placebo at 6 months. However, fewer repeat operations for reaccumulation of the subdural collection were performed in the dexamethasone group.[115] In addition, another study comparing burr hole craniotomy to burr hole craniotomy plus corticosteroids showed that adding steroid treatment increased medical complications, increased hospital length of stay, and increased the number of computed tomography scans.[116]

Platelet-activating factor

Platelet-activating factor has been shown to influence the formation of the neovascular membrane associated with chronic SDHs. Blocking activation of platelet-activating factor using the antagonist etizolam has been shown in small studies to decrease the need for surgery and recurrence of chronic subdurals after surgery.[117][118]

Tranexamic acid

CRASH-3, one large randomized controlled trial (RCT) of 12,737 patients, showed a reduction in mortality in patients with mild-to-moderate head injury (baseline Glasgow Coma Scale 9-15) who were treated with tranexamic acid (an antifibrinolytic agent) within 3 hours of injury, compared with those who were not.[119] However, its results should be interpreted with some caution due to: significance only in the subgroup analysis; change in recruitment (from within 8 to within 3 hours of injury); change in primary outcome (from all-cause to disease-specific mortality); and the risk of selection and observer bias. One RCT published in 2020 (n=1280, 20 centers, and 39 emergency medical services agencies in the US and Canada) compared tranexamic acid with placebo within 2 hours of moderate or severe traumatic brain injury.[120] A favorable functional neurologic outcome (measured as Glasgow Outcome Scale-Extended >4 at 6 months) occurred in 65% of patients in the tranexamic acid groups versus 62% with placebo. There was, however, no statistically significant difference in all-cause 28-day mortality, Disability Rating Scale score at 6 months, or progression of intracranial hemorrhage. So, although the results of CRASH-3 are promising, some uncertainty remains and guidance may vary. The Tranexamic Acid in Chronic Subdural Hematomas (TRACS) RCT seeks to evaluate the effect of the drug on: the resolution of chronic SDH without the need for surgery; and the reduction of recurrence of chronic SDH in patients treated with surgery.[121]

Middle meningeal artery (MMA) embolization

MMA embolization has emerged as a minimally invasive treatment to manage chronic SDH.[122][123] It can be used both as an adjunct treatment to prevent recurrence in surgically evacuated chronic SDH and as a stand‐alone procedure to treat both asymptomatic and symptomatic chronic SDH.[36] One systematic review of 15 studies with 193 procedures found a recurrence rate of 3.6% after MMA embolization. All other patients had symptomatic relief with significant reduction in hematoma size; no recurrences or procedure-related complications were observed.[124] One RCT compared surgery with and without MMA embolization in patients with chronic SDH. Further randomized trials are under way to understand appropriate patient selection, optimal embolization techniques, and timing of embolization.[125]