Objective: The cognitive trajectory of aging individuals with childhood-onset epilepsy is poorly understood. Our aim was to examine cognitive change over a 7-year period in aging individuals with epilepsy, originally recruited for prospective follow up in the early 1960's.

Method: 36 participants with childhood-onset epilepsy from a prospective population-based cohort and 39 controls participated in the 50-year and 57-year follow-up data collections. Eight participants had active epilepsy, 28 were in remission. Eleven neuropsychological tests were used to measure language/semantic function, episodic memory and learning, executive function, visuomotor function, and working memory. Regression-based standardized change scores were used to control for sources of error in test-retest assessments.

Results: Participants with epilepsy lacked a test-retest effect in language functions. A significant decline was found in participants with active epilepsy in episodic memory functions overall, and in those with remitted epilepsy in learning, immediate recall and set-shifting. The risk of clinically significant general cognitive decline was higher in participants with active epilepsy (OR 61.25, 95% CI 5.92-633.81, p = .0006). Among those with remitted epilepsy the risk was lower and non-significant (OR 2.19, 95% CI 0.58-8.23, p = .24).

Conclusions: Our results demonstrate poorer cognitive trajectories in participants with childhood-onset epilepsy compared to controls, particularly in those with active epilepsy. The risk of general cognitive decline was lower in participants with remitted epilepsy, but a decline in episodic memory functions was observed. Our findings likely reflect faster brain aging in childhood-onset epilepsy, even in individuals with early remission.