Change in non-motor symptoms after deep brain stimulation of bilateral subthalamic nuclei in patients with Parkinson’s disease

Abstract

BACKGROUND: The role of deep brain stimulation (DBS) of bilateral subthalamic nuclei (STN) in motor improvement of patients with Parkinson’s disease (PD) is well proven. But, the effect DBS has, on non-motor symptoms (NMSs), is still debatable. There are few studies, which have attempted to address this issue, though it also has significant effect on the quality of life of patients. PURPOSE: To study the impact of bilateral STN-DBS on NMSs in patients with PD. SUBJECTS AND METHODS: A prospective study was constructed from a center in South India. Thirty-five patients with PD who underwent bilateral STN-DBS were assessed preoperatively and 6 months postoperatively for NMSs with two well-established questionnaires: Non-motor Symptoms Questionnaire (NMS Q) and Non-motor Symptoms Scale (NMSS). The significance of improvement in scores was assessed with McNemar’s test, chi-square test, and paired two sample t-test for correlated samples. P value significance was set at <0.05. RESULTS: NMSs were seen in all patients. The most frequent symptoms preoperatively were insomnia (66%), nocturia (63%), urgency, and constipation (49% each). Statistically significant reduction after STN-DBS in overall NMSs was noted in both NMS Q (by 2.83, P = 0.008) and NMSS (by 17.40, P = 0.0013). Among the various domains, a significant reduction was observed in cardiovascular and sleep domains with improvement in individual questions on mood, insomnia, and light-headedness. Weight gain was more common after STN-DBS. CONCLUSION: Subthalamic nucleus stimulation causes significant improvement in NMSs with significant improvement in cardiovascular and sleep domains.