title: Effect of deep brain stimulation of the subthalamic nucleus on non-motor fluctuations in Parkinson's disease: two-years' follow-up.
abstract: BACKGROUND
  Deep brain stimulation of the subthalamic nucleus (STN-DBS) reduces motor fluctuations in Parkinson's disease (PD) but its effect on non-motor fluctuations (NMF) is not well known. In this study we assess the efficacy of STN-DBS on NMF two years after surgery.
  
  
  METHODS
  Autonomic, cognitive, psychiatric and sensory NMF in 20 patients were evaluated using a questionnaire designed to assess the frequency and severity of the NMF preoperatively and after two years of follow-up. The UPDRS scale was used for assessing the motor state.
  
  
  RESULTS
  Compared with the preoperative situation, STN-DBS at 2 years of follow-up was associated with a significant reduction in the number and severity of autonomic and psychiatric NMF in the "off" state (without medication), and in the severity of sensory NMF, which were not observed in the "on" state (with medication). A cross-sectional analysis at the two-year time-point of the four possible motor conditions (combining medication and stimulation) showed a reduction in the total number of NMF and in the severity of autonomic and sensory NMF after switching on the stimulation in the "on" state. Improvement of the UPDRS-motor score was correlated with a reduction in the severity but not in the frequency of NMF. A worsening of motor function after suppressing stimulation in the "off" state was not paralleled by a worsening of NMF.
  
  
  CONCLUSIONS
  After two years of follow-up, STN-DBS in the "off" medication was associated with a reduction in the frequency and severity of NMF. These results will need to be confirmed in controlled studies.
authors: Neurology and Neurosurgery, Clinica Universidad de Navarra, Pamplona, Spain.
authors: Sara
authors: S
authors: Ortega-Cubero
authors: Pedro
authors: P
authors: Clavero
authors: Cecilia
authors: C
authors: Irurzun
authors: Rafael
authors: R
authors: Gonzalez-Redondo
authors: Jorge
authors: J
authors: Guridi
authors: Jose A
authors: JA
authors: Obeso
authors: Maria C
authors: MC
authors: Rodriguez-Oroz
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D046690:Deep Brain Stimulation / Q000379:methods* / Q000639:trends; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology* / Q000523:psychology / Q000628:therapy*; D020531:Subthalamic Nucleus / Q000502:physiology* / Q000601:surgery; D011795:Surveys and Questionnaires; D016896:Treatment Outcome