Reduced movement-related beta desynchronisation in juvenile myoclonic epilepsy: A MEG study of task specific cortical modulation

Objective: We investigated differences in task induced responses in occipital and sensorimotor cortex between patients with juvenile myclonic epilepsy (JME) and healthy controls. Methods: Twelve patients with JME and 12 age-matched non-epilepsy volunteers performed visual and motor tasks during MEG. We used synthetic aperture magnetometry to localise areas of task-related oscillatory modulations, performed time-frequency analyses on the locations of peak task related power changes and compared power and frequency modulation at these locations between patients and controls. Results: Patients with JME had significantly reduced pre-movement beta event-related desynchronisation in the motor task compared to controls. No significant differences were seen in other motor-related responses, or visual oscillatory responses. Conclusions: Altered beta event-related desynchronisation may represent network specific dysfunction in JME possibly through GABAergic dysfunction. Significance: Characterising task specific cortical responses in epilepsy offers the potential to understand the patho-physiological basis of seizures and provide a window on disease and treatment effects. (C) 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.