Reduced movement-related β 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.