Cerebellar contribution to absence epilepsy

Abstract

The new aggregate data analyses revealed the earlier missing role played by the cerebellum long-term electrical stimulation in the absence epilepsy. Neurophysiologic data gained by authors favor that cerebellar serial deep brain stimulation (DBS) (100 Hz) causes the transformation of penicillin-induced cortical focal discharges into prolonged 3,5-3,75 sec oscillations resembling spikewave discharges (SWD) in cats. Such SWDs were not organized in the form of bursts and persisted continuously after stimulation. Therefore the appearance of prolonged periods of SWD is regarded as a tonic cerebellar influence upon pacemaker of SWD and might be caused by the long-lasting DBS-induced increase of GABA-ergic extrasynaptic inhibition in forebrain networks. At the same time, cerebellar DBS high-frequency (100 Hz) suppressed bursts of SWD observed during the phase of stimulation. Different types of cerebellar DBS upon epileptic activity emphasized the absence seizure facilitation discussed with the reviewed data on optogenetic stimulation, neuronal activity of cerebellar structures, and functional magnetic resonance imaging data.