title: The impact of bilateral subthalamic stimulation on non-motor symptoms of Parkinson's disease.
abstract: OBJECTIVE
  To evaluate the impact of bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) on the prevalence of non-motor symptoms reported by Parkinson's disease (PD) patients one year following surgery and to examine whether there was an association between number of non-motor symptoms reported and quality of life (QoL).
  
  
  METHODS
  Twenty-four patients who received bilateral STN DBS and had follow-up evaluations one year after surgery were included in this study. Patients' motor function was evaluated with the Unified Parkinson's Disease Rating Scale, non-motor symptoms were assessed with the Non-Motor Symptom questionnaire (NMSQuest) and quality of life was assessed with the PDQ-39.
  
  
  RESULTS
  There was a mean of 12 non-motor symptoms reported prior to surgery which was significantly reduced to a mean of 7 symptoms one year after surgery. Autonomic symptoms were the most frequently reported and demonstrated the greatest reductions following surgery. Twenty-seven of the 30 items represented in the NMSQuest were reported less frequently one year after surgery compared to before surgery. The reduction in non-motor symptoms was significantly correlated with total QoL scores and the subscales of mobility, activities of daily living, cognition and bodily discomfort.
  
  
  CONCLUSIONS
  Non-motor symptoms are common in patients with advanced PD. The number of non-motor symptoms was significantly decreased one year following bilateral STN DBS which was associated with a significant improvement in QoL. Further studies focused on specific non-motor symptoms are warranted in order to fully understand the impact and mechanisms of STN DBS on these symptoms.
authors.affiliation: Department of Neurosurgery, University of Kansas Medical Center, Kansas City, KS 66160, USA.
authors.forename: Jules M
authors.initials: JM
authors.lastname: Nazzaro
authors.forename: Rajesh
authors.initials: R
authors.lastname: Pahwa
authors.forename: Kelly E
authors.initials: KE
authors.lastname: Lyons
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology*; D000368:Aged; D046690:Deep Brain Stimulation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology / Q000523:psychology* / Q000628:therapy*; D011788:Quality of Life / Q000523:psychology*; D020531:Subthalamic Nucleus / Q000502:physiology / Q000503:physiopathology