Centre for Epilepsy Surgery “C. Munari”, Centre of Sleep Medicine, Department of Neuroscience, Niguarda Hospital, Milan, Italy
Centre for Advanced Studies in Sleep Medicine, Dept. of Neurosciences, Hôpital du Sacré-Coeur de Montréal, Université de Montréal, Montréal, Canada
Child Neuropsychiatry, IRCCS, G. Gaslini Institute, Dept. of Neuroscience (DINOGMI), University of Genoa, Italy
National Institute of Clinical Neuroscience, Budapest, Hungary
Correspondence: Péter Halász
National Institute of Clinical Neuroscience,
Lotz K.U.18, Budapest, 1026 Hungary
EEG activation of interictal epileptiform discharges (IEDs) during NREM sleep is a well-described phenomenon that occurs in the majority of epileptic syndromes. In drug-resistant focal epilepsy, IED activation seems to be related to slow wave activity (SWA), especially during arousal fluctuations, namely phase A of the cyclic alternating pattern (CAP). Conversely, in childhood focal epileptic syndromes, including Encephalopathy related to Status Epilepticus during slow Sleep (ESES), IED activation seems primarily modulated by sleep-inducing and maintaining mechanisms as reflected by the dynamics of spindle frequency activity (SFA) rather than SWA. In this article, we will review the effect of sleep on IEDs with a particular attention on the activation and modulation of IEDs in ESES. Finally, we will discuss the role of the thalamus and cortico-thalamic circuitry in this syndrome.