Influence of Deep Brain Stimulation on the Autonomic Nervous System in Patients Suffering from Parkinson's Disease

Introduction: Deep brain stimulation of the subthalamic nucleus (STN) is one of the most effective options of therapy in Parkinson's disease. On the other hand dysfunctions of the autonomic nervous system are very common in Parkinson's disease. How STN stimulation influences the autonomic nervous system, and therefore autonomic disorders, is not known yet. The aim of this study is to examine the coherences between autonomic dysfunctions and deep brain stimulation. Methods: So far 5 patients suffering from Parkinson's disease being treated with bilateral STN stimulation were examined. For this purpose blood pressure and heart rate during rest were taken and a heart rate variability test was performed. For investigations of the functions of sympathetic cutaneous vasoconstrictor neurons, a laser-Doppler was used for measuring vasoconstriction after deep inspiration. All examinations were randomized and performed on oral medication during „On“ as well as „Off“ states of the stimulator. Results: There was a trend to higher systolic and diastolic blood pressure in the supine position and an increased vasoconstriction due to increased activation of sympathetic cutaneous vasoconstrictor neurons during STN stimulation. Blood pressure during rest and heart rate variability were not influenced by deep brain stimulation. Conclusions: The results suggest an influence of STN stimulation on the sympathetic nervous system whereas tests examining mainly parasympathetic innervation have not been influenced. Further studies are needed to prove these preliminary data. Supported by the Deutsche Forschungsgemeinschaft (DFG Ba 1921/1–3).