Effect of Deep Brain Stimulation on Parkinson's Nonmotor Symptoms following Unilateral DBS: A Pilot Study

Parkinson’s disease (PD) management has traditionally focused largely on motor symptoms. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) and globus pallidus internus (GPi) are effective treatments for motor symptoms. Nonmotor symptoms (NMSs) may also profoundly affect the quality of life. The purpose of this pilot study was to evaluate NMS changes pre- and post-DBS utilizing two recently developed questionnaires. Methods. NMS-Q (questionnaire) and NMS-S (scale) were administered to PD patients before/after unilateral DBS (STN/GPi targets). Results. Ten PD patients (9 STN implants, 1 GPi implant) were included. The three most frequent NMS symptoms identified utilizing NMS-Q in pre-surgical patients were gastrointestinal (100%), sleep (100%), and urinary (90%). NMS sleep subscore significantly decreased (？1.6 points ± 1.8, ). The three most frequent NMS symptoms identified in pre-surgical patients using NMS-S were gastrointestinal (90%), mood (80%), and cardiovascular (80%). The largest mean decrease of NMS scores was seen in miscellaneous symptoms (pain, anosmia, weight change, and sweating) (？7 points ± 8.7), and cardiovascular/falls (？1.9, ). Conclusion. Non-motor symptoms improved on two separate questionnaires following unilateral DBS for PD. Future studies are needed to confirm these findings and determine their clinical significance as well as to examine the strengths/weaknesses of each questionnaire/scale. 1. Introduction The traditional approach to Parkinson’s disease (PD) patients has focused heavily on addressing motor symptoms and on-off fluctuations. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) and globus pallidus interna (GPi) are potentially effective treatments for these motor types of symptoms. Nonmotor symptoms (NMSs), however, are also common and debilitating and have been reported in up to 28% of PD cases. NMS have also been reported by some investigators as being more debilitating than motor symptoms [1]. Two scales that have recently been used to quantify nonmotor symptoms include the nonmotor Symptoms Questionnaire (NMS-Q) and the Non-motor Symptom Scale (NMS-S). Both scales were recently validated by Chaudhuri and colleagues [2–4]. The purpose of this pilot study was to evaluate NMS pre- and postoperatively in unilateral PD cases utilizing these scales to determine changes in overall NMS and to potentially guide a future study. 2. Methods Consecutive PD patients undergoing initial unilateral DBS implantation at the University of Florida were screened. All subjects were between the ages of 18 to 85,