The effects of subthalamic nucleus deep brain stimulation on precision grip abnormalities in Parkinson's disease

We studied grip force performance in 10 patients who were in a stable state after implantation of bilateral stimulating electrodes in the subthalamic nuclei (STN) to counter drug-resistant or drug-induced symptoms of advanced Parkinson's disease. The patients used a precision grip to lift an object which recorded grip force development and lift dynamics. Lifting was performed with stimulation on and with stimulation off under optimal medication. In the „off“ state the patients showed the profound bradykinesia and excessive levels of grip force development associated with Parkinson's disease from its early stages…