Sensory timing cues improve bradykinesia of grasping movements in Parkinson's disease: a comparison to the effects of STN stimulation

Here we study the effects of subthalamic nucleus stimulation and external timing cues on the bradykinesia of finger force development and arm movements when grasping to lift an instrumented object in Parkinson's disease. Six Parkinsonian subjects with chronic stimulation of the subthalamic nucleus and six sex- and age-matched healthy controls grasped, lifted and held an object between the tips of the thumb and index finger. The grip-lift task was either performed at self-determined speed or in response to an auditory cueing signal. Parkinsonian subjects performed the task with subthalamic nucleus stimulation swi…