Immediate effects of deep brain stimulation of the subthalamic nucleus on nonmotor symptoms in Parkinson's disease.

OBJECTIVE

To assess the immediate effects of deep brain stimulation of the subthalamic nucleus (STN-DBS) on nonmotor symptoms (NMS) in Parkinson's disease (PD).

BACKGROUND

Immediate effects of STN-DBS on motor functions are well accepted, but similar data on NMS are mainly lacking.

METHODS

34 PD patients who received bilateral STN-DBS were examined in medication Off state for frequency and severity of 10 NMS (dysphagia, anxiety, depression, fatigue, excessive sweating, inner restlessness, pain, concentration/attention, dizziness, bladder urgency) using a visual analogue scale (VAS) with STN-DBS Off and On. Motor assessments were done using UPDRS part III.

RESULTS

Independent of STN-DBS status, most frequent NMS was fatigue (85% of patients), followed by problems with concentration/attention (71%) and inner restlessness (53%). Frequencies of most NMS were similar in both STN-DBS statuses, while only inner restlessness was significantly decreased by STN-DBS. Severities of most NMS were significantly improved by STN-DBS on the cohort level, while only excessive sweating, pain and dizziness did not show significant severity changes. However, variable proportions of patients (15-71%, depending on the NMS) reported relevant improvements (>10% on VAS) by STN-DBS with fatigue showing the largest proportion of patients with symptom improvement (71%). There were no correlations of severity changes of NMS with motor improvement, demographic data and medication.

CONCLUSION

STN-DBS does not have major immediate effects on frequencies of NMS, but improves most NMS particularly psychiatric symptoms such as depression, anxiety and fatigue in a variable subset of patients. There is no indication that STN-DBS worsens NMS.