Time-Dependent Risk of Dementia Following Epilepsy Diagnosis: A Nationwide Cohort Study in South Korea.

Abstract

Objectives: To evaluate the dementia risk in patients with epilepsy compared with matched controls, analyze temporal variations in risk using nationwide cohort data, and investigate how age and sex modify dementia risk to identify high-risk subgroups for targeted intervention.

Methods: This retrospective cohort study used data from 2,740 patients with epilepsy aged 20-80 years and 27,400 controls matched 1:10 for age, sex, and year of health checkup from the Korean National Health Insurance Service (2002-2013). Time-stratified Cox proportional hazard models were used to estimate adjusted hazard ratios for dementia risk.

Results: Dementia risk was significantly higher in patients with epilepsy compared with that of controls (IRR: 3.65; 95% CI: 3.14-4.24), especially within the first 2 years post-diagnosis (aHR: 5.42; 95% CI: 4.30-6.83), peaking between 8 and 10 years (aHR: 8.25; 95% CI: 3.15-21.5). Younger patients (<60 years) were at higher risk, particularly during the first 2 years (aHR: 12.32 vs. 4.70). Men exhibited a greater risk than women in the initial 2 years post-diagnosis (aHR: 6.64 vs. 4.57).

Conclusion: The risk of dementia in patients with epilepsy varies with time since diagnosis, age, and sex. Early cognitive assessment and targeted interventions, particularly in younger male patients, are crucial to reduce the long-term burden of dementia. These results provide critical insight for clinicians and public health strategists to enhance the care of patients with epilepsy.