Risk for Late-Onset Epilepsy Associated With Cognitive, Neurologic Risk Factors

Risk for late-onset epilepsy among people with cognitive decline is associated with genetic, cognitive, cerebrovascular, and neurologic factors. These findings were published in JAMA Neurology.

In a longitudinal, multi-center study, researchers examined factors associated with the development of late-onset epilepsy among people with cognitive decline. Late-onset epilepsy was defined as seizures starting at or after age 60 years. The researchers used multivariable Cox regression for statistical analysis.

A total of 14,685 patients without an epilepsy diagnosis at enrollment were included in the study. Among these patients, 50% were women, 83% were White, and mean (SD) age was 73.82 (8.50) years. During follow-up, 221 patients developed late-onset epilepsy. Of patients who developed and did not develop late-onset epilepsy (n=14,464), mean (SD) ages were 72.74 (9.34) and 73.85 (8.48) years, 49% and 50% were women, 86% and 83% were White, and 81% and 56% had dementia (P <.001), respectively. Cognitive decline began at a median age of 68 (IQR, 59-75) and 70 (IQR, 64-76) years in the two cohorts (P =.002), respectively.

The researchers identified a number of cognitive factors significantly associated with the development of late-onset epilepsy:

• Parkinson disease (adjusted hazard ratio[aHR], 2.53; 95% CI, 1.08-5.95; P =.03)
• Dementia onset before age 60 years (aHR, 2.46; 95% CI, 1.53-3.95; P <.001)
• Worse cognitive function (aHR, 2.35; 95% CI, 1.97-2.79; P <.001)
• Cerebrovascular disease (aHR, 2.03; 95% CI, 1.37-3.01; P <.001)
• Alzheimer Disease (aHR, 1.68; 95% CI, 1.13-2.49; P =.01)
• Apolipoprotein e4 (APOE4) allele (aHR, 1.39; 95% CI, 1.04-1.86; P =.03)

Sensitivity analyses identified the same risk factors when late-onset epilepsy was defined as occurring at age 65 years and older, or when analyses were restricted to cases identified during follow-up.

Study limitations include an observational design and nonuniformity of follow-up periods.

The study authors concluded, “[O]ur study shows that certain genetic (APOE4 allele), cognitive (earlier age at cognitive decline onset, [Alzheimer Disease] dementia subtype, worse cognition), cerebrovascular (stroke/[transient ischemic attack]), and neurologic ([Parkinson Disease]) factors are associated with [late-onset epilepsy] in [people with cognitive decline].”

Disclosures: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.