Reaction Times in Epilepsy Across Different Stages

Abstract

Background: Cognitive changes are a significant concern among individuals with epilepsy, and reaction times (RT) provide a basic measure of cognitive processing. RT impairment is common in drug-resistant epilepsy (DRE) but less understood in newly diagnosed epilepsy (NDE) patients. To better characterize the impact of the course of epilepsy, it has been suggested that people with NDE be studied as a separate group. Aim: This study aims to compare RT across NDE, DRE, and healthy controls (HC), exploring whether RT deficits vary with epilepsy duration and task complexity. Methods We compared RTs between NDE, n=133, DRE, n=156, and HC, n=137. Tasks of increasing complexity included 4-alternative forced choice (4AFC) location detection, 2-AFC spatial pattern matching, and nonword rhyme judgment. Age and intelligence quotient were covariates. Results: Significant RT differences were found between HC and DRE (4AFC location detection: p< .001, effect size = 0.09), with DRE demonstrating the slowest RTs. Surprisingly, RTs in NDE did not differ significantly from HC. The difference between DRE and NDE was only significant on the 2-AFC spatial pattern matching task (p < .001, effect size = 0.07) Conclusion: The study reveals significant differences in RT between DRE and HC, particularly in tasks requiring complex decision-making. Notably, patients with NDE did not show significant RT deficits compared to DRE, except in more complex tasks. These findings suggest that RT deficits may worsen with task complexity. Factors contributing to RT impairment in DRE may include ongoing seizures and polytherapy. Impact: Computer-based assessments of RT are not readily available in clinical practice. Our data show that slowing of this basic process is notable in DRE and may relate to the everyday experience of subjective mental slowing commonly reported by this group.