, according to recent research published in Epilepsia.
In a retrospective cohort study, Ali Roghani, PhD, of the division of epidemiology at the University of Utah School of Medicine in Salt Lake City, and colleagues evaluated 938,890 veterans between 2000 and 2019 in the Defense Health Agency and the Veterans Health Administration who served in the US military after the September 11 attacks. Overall, 27,436 veterans met criteria for a diagnosis of epilepsy, 264,890 had received a diagnosis for a traumatic brain injury (TBI), and the remaining patients had neither epilepsy nor TBI.
Among the veterans with no epilepsy, 248,714 veterans had a TBI diagnosis, while in the group of patients with epilepsy, 10,358 veterans experienced a TBI before their epilepsy diagnosis, 1598 were diagnosed with a TBI within 6 months of epilepsy, and 4310 veterans had a TBI 6 months after an epilepsy diagnosis. The researchers assessed all-cause mortality in each group, calculating cumulative mortality rates compared with the group of veterans who had no TBI and no epilepsy diagnosis.
Dr. Roghani and colleagues found a significantly higher mortality rate among veterans who developed epilepsy compared with a control group with neither epilepsy nor TBI (6.26% vs. 1.12%; P < .01), with a majority of veterans in the group who died being White (67.4%) men (89.9%). Compared with veterans who were deceased, nondeceased veterans were significantly more likely to have a history of being deployed (70.7% vs. 64.8%; P < .001), were less likely to be in the army (52.2% vs. 55.0%; P < .001), and were more likely to reach the rank of officer or warrant officer (8.1% vs. 7.6%; P = .014).
There were also significant differences in clinical characteristics between nondeceased and deceased veterans, including a higher rate of substance abuse disorder, smoking history, cardiovascular disease, stroke, transient ischemic attack, cancer, liver disease, kidney disease, or other injury as well as overdose, suicidal ideation, and homelessness. “Most clinical conditions were significantly different between deceased and nondeceased in part due to the large cohort size,” the researchers said.
After performing Cox regression analyses, the researchers found a higher mortality risk in veterans with epilepsy and/or TBIs among those who developed a TBI within 6 months of an epilepsy diagnosis (hazard ratio [HR], 5.02; 95% CI, 4.21-5.99), had a TBI prior to epilepsy (HR, 4.25; 95% CI, 3.89-4.58), had epilepsy alone (HR, 4.00; 95% CI, 3.67-4.36), had a TBI more than 6 months after an epilepsy diagnosis (HR, 2.49; 95% CI, 2.17-2.85), and those who had epilepsy alone (HR, 1.30; 95% CI, 1.25-1.36) compared with veterans who had neither epilepsy nor a TBI.
“The temporal relationship with TBI that occurred within 6 months after epilepsy diagnosis may suggest an increased vulnerability to accidents, severe injuries, or TBI resulting from seizures, potentially elevating mortality risk,” Dr. Roghani and colleagues wrote.
The researchers said the results “raise concerns” about the subgroup of patients who are diagnosed with epilepsy close to experiencing a TBI.
“Our results provide information regarding the temporal relationship between epilepsy and TBI regarding mortality in a cohort of post-9/11 veterans, which highlights the need for enhanced primary prevention, such as more access to health care among people with epilepsy and TBI,” they said. “Given the rising incidence of TBI in both the military and civilian populations, these findings suggest close monitoring might be crucial to develop effective prevention strategies for long-term complications, particularly [post-traumatic epilepsy].”
