Focal Epilepsy Associates With Higher Risk for Incident Dementia

Focal epilepsy was associated with increased risk for dementia. The results from a cross-sectional study were published in JAMA Neurology.

Investigators from University of Oxford in the United Kingdom sourced data for this study from the UK Biobank. The subset of individuals (N=495,149) in the UK Biobank who attended both the cognitive assessment between 2006 and 2010 and the brain imaging evaluation between 2014 and 2020 were included in this analysis. Risk for all-cause dementia was evaluated on the basis of focal epilepsy, stroke, and migraine status with cardiovascular (CV) risk, cognitive testing results, and magnetic resonance imaging (MRI) data used as moderators of risk.

During follow-up, the study population was diagnosed with incident dementia (n=5471) or no incident dementia (n=464,138). The dementia and control groups had mean ages 65.3 (SD, 4.8) and 57.4 (SD, 8.1) years, 47.9% and 54.0% were women, 33.1% and 46.8% had obtained higher education, 18.1% and 20.1% were in the least deprived socioeconomic status quintile, and 9.0% and 27.3% had low cardiovascular risk, respectively.

At baseline, a total of 0.78% had a diagnosis of focal epilepsy, 1.3% had a history of stroke, and 2.93% had migraines.

After controlling for age, focal epilepsy was associated with decreased executive function compared with controls (mean difference [MD], -0.09; P <.001) and those with migraine (MD, -0.08; P <.001) but not compared with stroke (MD, 0.01; P =.91). Using MRI data, focal epilepsy associated with lower hippocampal volume (MD, -0.17; P =.03) and lower total gray matter volume (MD, -0.33; P <.001) compared with controls.

During follow-up, risk for incident dementia was higher for individuals with focal epilepsy (hazard ratio [HR], 4.02; 95% CI, 3.45-4.68) and stroke (HR, 2.56; 95% CI, 2.28-2.87) but not migraine (HR, 1.02; 95% CI, 0.85-1.21).

Integrating cardiovascular risk strengthened the relationship between focal epilepsy and dementia, in which individuals with focal epilepsy who had high CV risk were at an increased risk for incident dementia compared with those who had low CV risk (HR, 13.66; 95% CI, 10.61-17.60). Among the high CV risk cohort, the subset with focal epilepsy had a higher risk for incident dementia (HR, 3.73; 95% CI, 2.94-4.76) than those who had a stroke history (HR, 1.90; 95% CI, 1.65-2.20) compared with controls.

This study may have been biased, as diagnoses were based on hospital records which may not have been complete.

These data indicated that focal epilepsy was associated with greater risk for dementia compared with stroke or migraine among the general population. Study authors concluded, “[F]ocal epilepsy was significantly associated with worse cognitive performance, higher incident dementia risk, and widespread brain differences. Cardiovascular risk was associated with a substantially increased risk of dementia in people with focal epilepsy.”

This article originally appeared on Psychiatry Advisor