Abstract Details

The association of TBI and epilepsy in Veterans has been examined among those with combat deployments. We hypothesized that individuals with epilepsy would be more likely than those without epilepsy to have history of TBI and a history of deployment where blast injury/military exposures are more common.

To identify predictors of epilepsy in Post-9/11 Veterans. 

Retrospective observational study using merged Veterans Health Administration (VHA) and Department of Defense health data (2002-2019) for Veterans who entered VHA care 2002-2014. We identified epilepsy using ICD9/10 codes and use of anti-seizure medications. We identified TBI severity using ICD9/10 codes and TBI screening data, and mental/physical health comorbidities using ICD9/10 codes before the index date (EPILEPSY: date of the first anti-seizure medication after epilepsy-consistent diagnosis; No EPILEPSY: median time from first care in DoD to epilepsy [2625 days]). We excluded individuals with verified psychogenic non-epileptic seizures. We used logistic regression to identify predictors of epilepsy.

In this cohort (N=1,226,280), 30,993 (2.53%) met criteria for epilepsy. After controlling for mental/physical health comorbidities, odds of epilepsy were significantly lower for deployed (vs. non-deployed; AOR 0.76; 0.73-0.79). Compared to individuals without TBI, those with mTBI (OR 1.60; 1.55-1.66), moderate/severe TBI (OR 2.84; 2.36-2.61), penetrating TBI (OR 5.13; 4.71-5.58) had significantly higher odds of epilepsy. Other strong predictors included other neurological conditions such as ALS, MS, Parkinson’s disease (OR 6.73; 6.38-7.10), stroke (OR 3.61; 3.45-3.77), headache/migraine (OR 2.34; 2.28-2.40), and cardiac disease (OR 1.91; 1.84-1.98).

TBI, including mTBI, was associated with epilepsy, but those deployed were LESS likely to develop epilepsy. Chronic physical and mental health conditions that preclude deployment were associated with epilepsy and may be of equal concern to clinicians caring for patients with epilepsy and/or TBI; however more sophisticated statistical models are needed to better understand the interactions among TBI, deployment and chronic mental/physical comorbidities.