Risk and Onset Latency of Incident (New-onset) Epilepsy After Stroke in Post-9/11 U.S. Veterans: A Post-hoc Analysis of the Long-term Impact of Military-relevant Brain Injury Consortium (LIMBIC-CENC) Study Data
Manaz Rezayee1, Jacqueline Hirschey1, Megan Amuan2, Zulfi Haneef3, Linda Williams4, Ian Stewart5, Elisabeth Wilde6, Eamonn Kennedy7, Marissa Kellogg8, Mary Jo Pugh6
1OHSU and Portland VA HCS, 2Salt Lake City VAMC, 3Houston VAMC, 4Roudebush VAMC, 5Uniformed Services University of the Health Sciences, 6University of Utah School of Medicine and Salt Lake City VA HCS, 7University of Utah School of Medicine, 8VA Portland Healthcare System, Dept of Neurology
Objective:

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

Background:

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.

Design/Methods:

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.

Results:

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]).

Conclusions:

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).

10.1212/WNL.0000000000206318