Great Geographic Variance Seen for Epilepsy Incidence in U.S. Adults

MONDAY, Dec. 1, 2025 (HealthDay News) — Geographic and sociodemographic factors appear to influence the incidence of epilepsy in older U.S. adults, according to a study published online Nov. 10 in JAMA Neurology.

Weichuan Dong, Ph.D., from Case Western Reserve University in Cleveland, and colleagues examined geographic patterns of epilepsy incidence among older adults in the United States. Medicare administrative claims (2016 to 2019) for all counties in the contiguous United States were used to create a random sample of 4.8 million Medicare fee-for-service beneficiaries, with non-Hispanic Black and Hispanic beneficiaries oversampled at rates of 1.50 and 1.75 times. County-level data were aggregated into 692 “MaxCounties,” each containing at least 11 incident cases.

The researchers found that incidence rates across MaxCounties varied more than 10-fold (range, 141 to 1,476 per 100,000). Higher incidence was associated with insufficient sleep, heat index, physical inactivity, uninsured rate, proportion of non-Hispanic Black residents, and obesity prevalence. Compared with the lowest tertile for insufficient sleep, MaxCounties in the highest tertile had nearly doubled the odds of high epilepsy incidence (odds ratio [OR], 1.99). High epilepsy incidence was also associated with a lack of household vehicle access (OR, 1.93).

“By applying advanced geospatial mapping to Medicare data, we revealed striking clusters of high epilepsy rates across parts of the South — what we call the “epilepsy belt,”” Dong said in a statement. “Understanding where the burden lies is the first step toward uncovering why and helping communities reduce risk.”

One author disclosed ties to the pharmaceutical industry.

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