title: Efficacy of deep brain stimulation of the subthalamic nucleus in Parkinson's disease 4 years after surgery: double blind and open label evaluation.
abstract: OBJECTIVE
  To evaluate the long term (4 years) efficacy of deep brain stimulation (DBS) of the subthalamic nucleus (STN) in advanced Parkinson's disease.
  
  
  METHODS
  We performed a double blind crossover evaluation of the efficacy of DBS of the STN in the "off" medication condition in 10 patients with Parkinson's disease. Assessments included the Unified Parkinson's Disease Rating Scale (UPDRS) part III (motor) and two timed tests (arm tapping and walking). Open evaluation of the effect of stimulation in the off and on drug states preoperatively and at 1 and 4 years postoperatively was also conducted. The latter assessment included the UPDRS parts II (activities of daily living) and III (dyskinesia scale and global assessment) as judged by the patient and examiner. The mean amount of levodopa daily dose at base line, 1 year, and 4 years after surgery was compared.
  
  
  RESULTS
  A significant (p<0.04) effect of stimulation was observed in the overall group regarding both the UPDRS motor and the timed tests. Open evaluation also showed a significant benefit of STN DBS with respect to preoperative assessment in both the motor and activities of daily living scales, dyskinesia scale, and in global assessment. Levodopa daily dose was reduced by 48% and 50% at 1 and 4 years, respectively. There was no difference between the 1 and 4 years evaluations in any of the parameters evaluated. Complications due to stimulation were minor.
  
  
  CONCLUSIONS
  DBS of the STN provides a significant and persistent anti-parkinsonian effect in advanced Parkinson's disease 4 years after surgery.
authors.affiliation: Department of Neurology and Neurology, Neuroscience Center, Clinica Universitaria and Medical School, Universidad de Novarra, 31008 Pamplona, Spain.
authors.forename: M C
authors.initials: MC
authors.lastname: Rodriguez-Oroz
authors.forename: I
authors.initials: I
authors.lastname: Zamarbide
authors.forename: J
authors.initials: J
authors.lastname: Guridi
authors.forename: M R
authors.initials: MR
authors.lastname: Palmero
authors.forename: J A
authors.initials: JA
authors.lastname: Obeso
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000978:Antiparkinson Agents / Q000008:administration & dosage / Q000627:therapeutic use; D018592:Cross-Over Studies; D004311:Double-Blind Method; D020820:Dyskinesias / Q000209:etiology / Q000628:therapy; D004599:Electric Stimulation Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007980:Levodopa / Q000008:administration & dosage / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009048:Motor Skills; D010300:Parkinson Disease / Q000601:surgery / Q000628:therapy*; D020531:Subthalamic Nucleus / Q000502:physiology*; D016896:Treatment Outcome
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa