Benign epilepsy with centrotemporal spikes: Is there a thalamocortical network dysfunction present?

Introduction: Benign epilepsy of childhood with centrotemporal spikes (BECTS) is one of the most frequently seen epileptic syndromes in childhood. It is characterized by centrotemporal spikes (CTS) on electroencephalography (EEG) that are typically activated by drowsiness and stage N2 sleep. The location, frequency, and amplitude of the spikes may vary in different EEG records of the same patient, supporting the presence of a global pathology rather than a focal one. Despite the well-known relation between BECTS and stage N2 sleep, the results of sleep studies have been diverse and have mainly focused on sleep cycles. The characteristics of sleep spindles in the interictal periods have not been studied well.

Methods: A retrospective study involving patients with BECTS who were admitted to the Gazi University, Faculty of Medicine, Department of Pediatric Neurology from January 2017 to October 2018 was conducted herein. Patients with BECTS and age-matched controls who had stage N2 sleep records of 10 min were enrolled for spindle amplitude (peak-to-peak difference in spindle voltage), frequency (number of waveforms per second), and duration and density (number of spindle bursts/minute of stage N2 sleep).

Results: A total of 30 children with BECTS and 20 age-matched healthy peers were enrolled in the study. There were no significant differences between the age and sex of the patients. Statistically significant lower mean values of the amplitude, and duration and density of the spindle activity were observed in patients with BECTS when compared to the controls (P: 0.034, P: 0.016, and 0.020, respectively). Additionally, the risk of epilepsy was found to increase by 1.9 %, by the decrease of the mean amplitude of the spindles by 1 mV when compared to control group.

Conclusion: The interictal records of stage N2 sleep differed in the patients with BECTS when compared to the controls. Findings related to the stage N2 sleep of the present study may suggest a network problem involving the thalamus and thalamocortical pathways in patients with BECTS.