Abstract Details

Strokes are a known cause of epilepsy. The latency (i.e. time from stroke to onset of incident epilepsy) can be highly variable. This study uses data from LIMBIC-CENC (a study designed to examine long-term outcomes of mild TBI) to explore the relationship between stroke and subsequent new-onset epilepsy in post-9/11 Veterans.

To assess the risk and onset latency of incident epilepsy following stroke in post-9/11 U.S. veterans.

Post hoc analysis of the retrospective cohort LIMBIC-CENC Phenotype study. Participants had care documented for at least 3 years in DoD and 2 years in VHA (10/1/1999-9/30/2019) with follow-up data through 9/30/2020. Inclusion criteria: stroke ICD codes during the study period. New-onset epilepsy was defined by a validated algorithm using diagnostic codes and pharmacy records. Exclusion criteria: seizure history prior to stroke, anoxic brain injury within 7 days of stroke, and TBI with unclear severity.

Of the 2,530,847 post-9/11 Veterans, 28,196 (1.1%) participants met inclusion criteria for stroke and no prior history of seizures. 80.1% were male and median age was 44 years [IQR 33-52]. After stroke, 2,874 (10.2%) developed epilepsy and 1,566 (5.6%) died during the study period. The median latency to epilepsy onset after stroke was 9.5 months [IQR 0.7-37.2] and maximum latency was 196.2 months. Veterans with stroke who developed epilepsy were younger at the time of stroke (median 40.5 years [IQR 30-37.2]) than veterans who did not develop epilepsy and survived (median 44 [IQR 33-51]) and those who died during the study period (median 51 [IQR 42-60]).

At least 10% of Veterans who suffer strokes will subsequently develop epilepsy; 50% develop epilepsy within 9.5 months of stroke, while 25% develop epilepsy after prolonged latencies of more than 3 years (37.2 months).