Neurophysiological Studies in Patients With Paroxysmal Hyperkinetic Movement Disorders

Objective: The primary objective of this study is to determine the brain regions responsible during attacks for psychogenic paroxysmal hyperkinetic movement disorders using functional magnetic resonance imaging (fMRI). The secondary objective is to determine the neurophysiology during attacks for the same subjects compared to normal controls using electroencephalography (EEG) and Startle Reflex. Study population: Psychogenic paroxysmal hyperkinetic movement disorder patients and a control group of healthy volunteers. Design: fMRI: Anatomical MRI and fMRI sequences are performed to obtain blood-oxygenation level-dependent (BOLD) imaging of brain activation during (1) triggered or provoked involuntary hyperkinetic movements and voluntary imitated movements in subjects with psychogenic paroxysmal hyperkinetic movement disorders and (2) voluntary imitated movements and rest states in healthy volunteers. EEG: EEG will be recorded for jerk-locked back-averaging analysis. Startle Reflex: Electromyography (EMG) will be recorded during exposure to auditory stimuli. Outcome measures: fMRI: BOLD will be obtained using baseline correction. EEG Startle Reflex: The latency, mean amplitude, and habituation of EMG amplitude will be measured.