Finding the center of Parkinson´s disease. A novel measurement device for quantifying motor symptoms during DBS-surgery

Morbus Parkinson is a widespread disease amongst the elderly people. With increasing life expectancy the numbers of patients with Parkinsons disease are rising. Over the last decade, Deep Brain Stimulation (DBS) of certain nuclei within the basal ganglia has been established as an effective treatment for patients with advanced Parkinsons disease (PD) and motor complications not longer adaequatly treated by medication. The main target for DBS in PD, that is chronically stimulated with small electric pulses, is the subthalamic nucleus (STN). Although this target is anatomically very well defined, hitting the right target within the target, is still challenging for neurosurgeons and neurophysiologists. The device introduced in this paper is supposed to help the physicians to find the right stimulation spot. Currently neurophysiologists test different areas within the subthalamic nucleus for the best outcome on the patients symptoms during the surgical procedure of electrode implantation. The decision which position of the electrode is the final implantation site is made, not based on hard objective physical data, but on the expert observations of the neurophysiologist. An intra-operative measurement of Parkinsons symptoms will increase the chances of a successful and effective implantation of DBS-Stimulation Electrodes, by enabling the neurophysiologist to base his decision on measured data. A prototype is described with detail to the overall concept of the device and the mechanical sensor setting.