To determine whether standalone middle meningeal artery embolization (MMAE) is associated with reduced dementia risk compared with conservative management among patients with non-surgical non-acute subdural hematoma (NASDH).

NASDH is the most common cranial neurosurgical disease that has a predilection for elderly patients, and it is associated with cognitive dysfunction and decline. MMAE has shown efficacy in reducing NASDH recurrence and promoting hematoma resorption, but its potential impact on long-term cognitive outcomes is unexplored.

This was a multicenter retrospective cohort study of the TriNetX US collaborative research network. Adult patients with newly-diagnosed NASDH who did not undergo surgical drainage were included. Patients with known dementia at the time of NASDH diagnosis were excluded. Patients who were treated with standalone MMAE were compared to those who received conservative management (CM) only. The primary outcome was new-onset dementia during a three-year study follow-up period. Secondary outcomes included all-cause mortality. One-to-one propensity score matching was performed to account for confounding and indication bias. Outcomes were compared using time-to-event analyses with Kaplan-Meier curves and Cox proportional hazards models.