Study Suggests Penetrating Traumatic Brain Injury Strongly Associated with Risk of Epilepsy among OEF/OIF Veterans
BACKGROUND:
Many OEF/OIF Veterans have reported experiencing a traumatic brain injury (TBI), with approximately 15% to 19% reporting a TBI with either loss of consciousness or altered mental status. Studies of Veterans from previous conflicts (i.e., WWII, Korean War) and civilian-based studies show a link between TBI and epilepsy; in addition, a recent investigation by the DoD suggests that epilepsy incidence increased by 52% from 2006 to 2010, with about 8% of those with epilepsy having a previously diagnosed TBI. This retrospective study examined the association between epilepsy and TBI, including penetrating TBI (pTBI), in OEF/OIF Veterans. Using VA data, investigators identified 256,284 OEF/OIF Veterans who received VA healthcare at least once in both FY09 and FY10. Investigators also examined inpatient, outpatient, and pharmacy data for these Veterans from FY02 through FY10. In addition to identifying Veterans who met epilepsy criteria [prevalence was 10.6 per thousand (n=2,719) in FY10], other measures included TBI classification (pTBI vs. "other" TBI) and demographics, as well as medical and psychiatric conditions associated with epilepsy, such as stroke and schizophrenia, respectively. PTSD also was examined, as it is a common comorbidity in Veterans with TBI and has been strongly associated with psychogenic non-epileptic seizures.
FINDINGS:
- Among OEF/OIF Veterans, epilepsy was associated with previous TBI diagnosis. The estimated risk of epilepsy among Veterans with pTBI was nearly 18 times greater than among those without TBI, even after controlling for other factors. When examined separately, risk for epilepsy was also elevated among Veterans with severe, moderate, and mild TBI.
- Even among this relatively young group of Veterans, stroke was one of the strongest risk factors for epilepsy. Veterans with epilepsy also were more likely to be younger than 50 years and white, and were more likely to have previously diagnosed substance use disorder, depression, anxiety, bipolar disorder, schizophrenia, and PTSD than those without epilepsy. Headache, cardiac conditions, cerebrovascular disease, and cognitive impairment/dementia, were also epilepsy risk factors.
LIMITATIONS:
- Investigators relied on ICD-9-CM codes and VA medication data to identify epilepsy – and did not have access to information about non-VA care for Veterans with epilepsy.
- Investigators were unable to assess whether TBI was combat related and did not examine the mechanism of injury (i.e., blast, motor vehicle accident), the number of mild TBI exposures, or the time since exposure – each of which may be relevant to epilepsy risk.
IMPLICATIONS:
- An increasing burden of epilepsy in this Veteran population is likely. These Veterans should be followed closely, and systems of care, such as VA Epilepsy Centers of Excellence, should be prepared to provide epilepsy specialty care.
AUTHOR/FUNDING INFORMATION:
This study was funded by HSR&D (DHI 09-237). Drs. Pugh, Jaramillo and Eapen are part of the South Texas Veterans Health Care System.
Pugh M, Orman J, Jaramillo C, et al. The Prevalence of Epilepsy and Association with Traumatic Brain Injury in Veterans of the Afghanistan and Iraq Wars. The Journal of Head Trauma Rehabilitation. April 1, 2014;e-pub ahead of print.
