Late-onset epilepsy tracked vascular risk factors and prior stroke across six cohorts

Design

Individual-participant meta-analysis of 6 prospective cohorts

Population

42,257 US adults, mean age 71, followed 9.3 years

Primary outcome

Incident epilepsy with onset at ≥65 years

Effect

Prior stroke HR 1.99 (1.63–2.43); diabetes HR 1.42 (1.25–1.62); smoking HR 1.39 (1.18–1.64)

This individual-participant meta-analysis, published in JAMA Neurology on 19 October, pooled six US population cohorts — including ARIC, the Cardiovascular Health Study, MESA and REGARDS — with 42,257 older adults followed for a mean of 9.3 years. Epilepsy beginning at 65 or older was identified mainly through Medicare claims.

Late-onset epilepsy developed in 3.5% (3.8 per 1,000 person-years). After full adjustment, it was more likely with current smoking (HR 1.39), hypertension (1.17), diabetes (1.42), chronic kidney disease (1.29) and prior stroke (1.99), and with one or two APOE ε4 alleles (1.22 and 1.84). The associations were similar across age, sex and ethnic groups.

The findings support the view that many new epilepsies in older people are a manifestation of cerebrovascular disease, even without a clinical stroke. Claims-based diagnosis will have misclassified some cases, and the design shows association rather than cause. Still, it reframes a first seizure in an older adult as a vascular event worth a vascular work-up.

• In a first unprovoked seizure after 65, assess vascular risk factors as you would after a TIA.
• Look for small-vessel disease and silent infarcts on MRI in older adults with new epilepsy.
• Treat blood pressure, diabetes, smoking and lipids in late-onset epilepsy as part of the neurological management.
• Late-onset epilepsy may also be an early sign of cognitive decline; record a baseline cognitive assessment.

Why it matters

It moves late-onset epilepsy from an isolated neurological diagnosis to part of a patient's vascular risk profile.

Don't overread it

This shows association; it does not establish that treating vascular risk factors lowers the chance of late-onset epilepsy.

The statistics, in plain English

Hazard ratios of 1.17 to 1.99 mean these factors were linked to between 17% and about 100% higher rates of developing epilepsy. Because this is observational, it cannot show that controlling them prevents epilepsy.

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