Association of race and ethnicity to incident epilepsy [or epileptogenesis] after subdural hematoma.

Objective: To determine whether race is associated with the development of epilepsy following subdural hematoma (SDH), we identified adult survivors of SDH in a statewide administrative dataset and followed them for at least one year for revisits associated with epilepsy. Methods: We performed a retrospective cohort study using claims data on all discharges from emergency departments (ED) and hospitals in California. We identified adults (age≥18) admitted from 2005-2011 with first-time, traumatic and non-traumatic SDH. We used validated diagnosis codes to identify a primary outcome of ED or inpatient revisit for epilepsy. We used multivariable Cox regression for survival analysis to identify demographic and medical risk factors for epilepsy. Results: We identified 29,342 survivors of SDH (mean age 71.2 [SD 16.4], female sex 11,954 [41.1%]). 3,230 (11.0%) patients had revisits to ED’s and/or hospitals with a diagnosis of epilepsy during the study period. Black patients (n=1,684 [5.7%]) had significantly increased risk compared to white patients (n=16,945 [57.7%]; HR 1.45, CI 1.28-1.64, p Conclusions: We found an association between black race and ED and hospital revisits for epilepsy after SDH, establishing the presence of a racial subgroup that is particularly vulnerable to post-SDH epileptogenesis.