November 17, 2020

Late-Onset Epilepsy Tied to a Threefold Increased Dementia Risk

Literature review, originally published on Neurology Reviews

Late-onset epilepsy is linked to a substantial increased risk of subsequent dementia. Results of a retrospective analysis show that patients who develop epilepsy at age 67 or older have a threefold increased risk of subsequent dementia versus their counterparts without epilepsy.

“This is an exciting area, as we are finding that just as the risk of seizures is increased in neurodegenerative diseases, the risk of dementia is increased after late-onset epilepsy and seizures,” study investigator Emily L. Johnson, MD, assistant professor of neurology at Johns Hopkins University, Baltimore, said in an interview. “Several other cohort studies are finding similar results, including the Veterans’ Health Study and the Framingham Study,” she added.

The researchers found that of 9,033 study participants, 671 had late-onset epilepsy. The late-onset epilepsy group was older at baseline (56.5 vs. 55.1 years) and more likely to have hypertension (38.9% vs. 33.3%), diabetes (16.1% vs. 9.6%), and two alleles of APOE4 genotype (3.9% vs. 2.5%), compared with those without the disorder.

In all, 1,687 participants developed dementia during follow-up. The rate of incident dementia was 41.6% in participants with late-onset epilepsy and 16.8% in participants without late-onset epilepsy. The adjusted hazard ratio of subsequent dementia in participants with late-onset epilepsy versus those without the disorder was 3.05 (95% confidence interval, 2.65-3.51).