OBJECTIVETo detect the differences in subcortical structures between patients with paroxysmal kinesigenic dyskinesia (PKD) and normal subjects during movement preparation and execution.

METHODSThe PKD patients performed a movement task, in which a CUE signal (preparation) indicated the movement sequence prior to the appearance of an imperative GO signal (execution). Event-related functional magnetic resonance imaging (fMRI) and 3dDeconvolve program of AFNI were used to estimate the hemodynamic response function and to generate activation maps.

RESULTDuring movement preparation, the activated brain areas in PKD patients were less than those of normal subject, and there was no activation in basal ganglia in PKD patients. During execution, the activation was also less in PKD patients except in bilateral M1.

CONCLUSIONDuring intermission, abnormalities of the brain still exist in PKD patients when during preparing or performing movement. The movement circuit in the brain displays an unusual state. The attack may be caused by reducing of inhibition in brain areas.