Functional Connectivity in Self-limited Epilepsy with Centrotemporal Spikes (SeLECTS) Increases with Epilepsy Duration and Interictal Spike Exposure.

Objective: To determine the impact of epilepsy duration and interictal spikes on functional connectivity in children with Self-Limited Epilepsy with Centrotemporal Spikes (SeLECTS). Methods: Connectivity was calculated from electroencephalograms (EEGs) of 68 children with SeLECTS and 65 age and sex-matched controls using the weighted phase lag index. SeLECTS EEGs were categorized by epilepsy duration (shorter or longer than 6 months) to assess progressive connectivity changes. To investigate the impact of spikes on connectivity, 19 SeLECTS patients who underwent two EEGs were analyzed longitudinally, comparing those whose spikes persisted versus resolved over time. Analyses focused on connectivity during sleep. Results: Connectivity increased with epilepsy duration, being lowest in controls, intermediate in patients with shorter epilepsy duration, and highest in those with longer duration. Changes were initially greatest within the right occipital region and became more widespread with longer epilepsy duration. Longitudinally, patients with persistent spikes showed increasing connectivity over time, while those with spike resolution demonstrated decreasing connectivity, resulting in significant between-group differences. Conclusions: Functional connectivity in SeLECTS increases progressively with epilepsy duration and spike exposure, suggesting that ongoing spikes drive neural network alterations. Significance: Spikes are a potential treatment target to prevent progressive brain network disruption and preserve cognitive outcomes.