Older adults with late-onset epilepsy experience increased mortality risk

Individuals with late-onset epilepsy experienced an increased risk for death compared with individuals without epilepsy, even after adjustment for comorbidities, according to findings published in Neurology.

Researchers found that the “majority” of excess mortality in individuals with late-onset epilepsy was related to stroke and dementia.

“Late-onset epilepsy (ie, starting at age 65 or older) affects a large and growing number of persons worldwide,” the researchers wrote. “Numerous population-based studies have shown that people with epilepsy (diagnosed at any age) have an increased mortality rate compared to those without epilepsy and are at an increased a risk of injuries associated with seizures, such as fractures, drownings and motor vehicle accidents. People diagnosed with epilepsy are also at risk for sudden unexplained death in epilepsy.”

However, it is not yet known whether mortality is also higher in individuals with late-onset epilepsy — and what the causes of mortality in this population may be. Emily L. Johnson, MD, an assistant professor of neurology at Johns Hopkins Medicine, and colleagues used data from the Atherosclerosis Risk in Communities (ARIC) study cohort to examine mortality rates among older adults with and without late-onset epilepsy.

The ARIC study, which began between 1987 and 1989, included 15,792 primarily Black and white men and women in four U.S. communities. The researchers used CMS fee-for-service claim codes to identify incident cases of epilepsy in individuals aged 67 years and older. They determined the hazard of mortality related to late-onset epilepsy and adjusted for demographics as well as vascular risk factors. They examined death certificate data to determine dates and causes of death, according to the study results.

The current analysis included 9,090 participants. Over a median follow-up period of 11.5 years, 678 developed late-onset epilepsy after age 67 years, with an incidence of 29 per 1,000 person-years. This incidence was like that seen in other studies, according to the researchers.

Johnson and colleagues reported that individuals who developed late-onset epilepsy experienced an increased hazard for mortality compared with individuals who did not, with an adjusted HR of 2.39 (95% CI, 2.12-2.71). The researchers observed excess mortality due to stroke, dementia, neurologic conditions and end-stage renal disease among participants with vs. without late-onset epilepsy. They also reported that four deaths (1.1%) were attributable to seizure-related causes.

“These mortality risks suggest that clinicians should address modifiable vascular risk factors with lifestyle and medication changes as appropriate,” the researchers wrote. “Future studies with additional clinical data available regarding the type of epilepsy, seizure frequency, and medication treatment to determine the effects of these factors on mortality would be of great importance in this population.”