Functional impairment of somatosensory association cortex in Angelman syndrome

Abstract

Background: Angelman syndrome is a genetic neurodevelopmental disorder recognised to show characteristic (non-epileptic) high-amplitude slow rhythmic electroencephalographic patterns. These hypersynchronous neuronal activities have been studied to approach the pathophysiology of the condition. Aim: to analyse these patterns with enhanced recording technique (high-density EEG) and analysis method, using a recently developed technique for identifying subtle short-term repeated patterns that may be masked by non-stationarities, noise, and artefacts. Material and methods: 4 children (aged 2 to 5) with Angelman syndrome due to 15q11-q13 deletion. High-density EEG were recorded at resting state using the ActiveTwo system (Biosemi) with size-adapted head caps with 128 sintered active Ag/AgCl electrodes positioned radially equidistant from CZ. Sampling rate was 2048 Hz. We performed a channel spectra for the 128 channel of a 5 minutes resting state recording in order to find regions of interest for slow frequency bands. We performed a wave trigger averaging over the peaks of activity of this region and averaged it on a period of 2 seconds (-1,1second) centered on the peak activity. To localise the generator of this activity, we performed an inverse solution analysis with Sloreta matrix.