Internal Tempo during the Interictal Period in Patients with Temporal Lobe Epilepsy: Dependence on the Laterality of Epileptiform Discharges

Abstract

Purpose: To investigate the internal tempo of passage of time in patients with temporal lobe epilepsy (TLE), and to assess possible dependence on the laterality of interictal epileptiform discharges (IEDs).
Methods: A verbal estimation task was administered to 30 right-handed patients with TLE in whom unilateral IEDs were repeatedly observed on interictal scalp electroencephalogram.
Results: Patients with IEDs on the right side showed a significantly longer subjective duration of one minute than did patients with IEDs on the left.
Discussion: IEDs on the non-dominant side may interfere with the activities of the supratemporal gyrus on the ipsilateral side during mental counting. However, the locus and nature of the internal clock that generates internal tempo remain unknown.