Reduced postmovement cortical inhibition in patients with paroxysmal kinesigenic dyskinesia.

Abstract

To characterize movement-related neural oscillatory activity and to clarify its neurophysiologic role in paroxysmal kinesigenic dyskinesia (PKD). We recorded neuromagnetic event-related desynchronization (ERD) and event-related synchronization (ERS) activities in response to a self-paced finger-lifting task in 16 patients with PKD and 17 healthy controls. The amplitude of α-ERD was comparable between the healthy controls and patients with PKD, whereas either the contralateral or ipsilateral β-ERS was decreased. The peak latency of contralateral β-ERS was delayed in patients with PKD. Patients with less frequent dyskinetic attacks demonstrated a larger ipsilateral β-ERS. Moreover, some patients with PKD revealed a lesser degree of contralateral preponderance of β-ERS generation. The present data imply a decreased postmovement inhibition of motor cortex in patients with PKD, and the inhibitory function in the contralateral hemisphere is more affected than that in the ipsilateral hemisphere.