title: Subthalamic nucleus versus globus pallidus bilateral deep brain stimulation for advanced Parkinson's disease (NSTAPS study): a randomised controlled trial.
abstract: BACKGROUND
  Patients with advanced Parkinson's disease often have rapid swings between mobility and immobility, and many respond unsatisfactorily to adjustments in pharmacological treatment. We assessed whether globus pallidus pars interna (GPi) deep brain stimulation (DBS) gives greater functional improvement than does subthalamic nucleus (STN) DBS.
  
  
  METHODS
  We recruited patients from five centres in the Netherlands who were aged 18 years or older, had idiopathic Parkinson's disease, and had, despite optimum pharmacological treatment, at least one of the following symptoms: severe response fluctuations, dyskinesias, painful dystonias, or bradykinesia. By use of a computer-generated randomisation sequence, we randomly assigned patients to receive either GPi DBS or STN DBS (1:1), applying a minimisation procedure according to drug use (levodopa equivalent dose <1000 mg vs ≥1000 mg) and treatment centre. Patients and study assessors (but not those who assessed adverse events) were masked to treatment allocation. We had two primary outcomes: functional health as measured by the weighted Academic Medical Center Linear Disability Scale (ALDS; weighted by time spent in the off phase and on phase) and a composite score for cognitive, mood, and behavioural effects up to 1 year after surgery. Secondary outcomes were symptom scales, activities of daily living scales, a quality-of-life questionnaire, the occurrence of adverse events, and drug use. We used the intention-to-treat principle for all analyses. This trial is registered with www.controlled-trials.com, number ISRCTN85542074.
  
  
  RESULTS
  Between Feb 1, 2007, and March 29, 2011, we enrolled 128 patients, assigning 65 to GPi DBS and 63 to STN DBS. We found no statistically significant difference in either of our primary outcomes: mean change in weighted ALDS (3·0 [SD 14·5] in the GPi group vs 7·7 [23·2] in the STN group; p=0·28) and the number of patients with cognitive, mood, and behavioural side-effects (36 [58%] of 62 patients in the GPi group vs 35 [56%] of 63 patients in the STN group; p=0·94). Secondary outcomes showed larger improvements in off-drug phase in the STN group compared with the GPi group in the mean change in unified Parkinson's disease rating scale motor examination scores (20·3 [16·3] vs 11·4 [16·1]; p=0·03), the mean change in ALDS scores (20·3 [27·1] vs 11·8 [18·9]; p=0·04), and medication (mean levodopa equivalent drug reduction: 546 [SD 561] vs 208 [521]; p=0·01). We recorded no difference in the occurrence of adverse events between the two groups. Other secondary endpoints showed no difference between the groups.
  
  
  CONCLUSIONS
  Although there was no difference in our primary outcomes, our findings suggest that STN could be the preferred target for DBS in patients with advanced Parkinson's disease.
  
  
  BACKGROUND
  Stichting Internationaal Parkinson Fonds, Prinses Beatrix Fonds, and Parkinson Vereniging.
authors.affiliation: Department of Neurology, Academic Medical Center, Amsterdam, Netherlands.
authors.forename: Vincent J J
authors.initials: VJ
authors.lastname: Odekerken
authors.forename: Teus
authors.initials: T
authors.lastname: van Laar
authors.forename: Michiel J
authors.initials: MJ
authors.lastname: Staal
authors.forename: Arne
authors.initials: A
authors.lastname: Mosch
authors.forename: Carel F E
authors.initials: CF
authors.lastname: Hoffmann
authors.forename: Peter C G
authors.initials: PC
authors.lastname: Nijssen
authors.forename: Guus N
authors.initials: GN
authors.lastname: Beute
authors.forename: Jeroen P P
authors.initials: JP
authors.lastname: van Vugt
authors.forename: Mathieu W P M
authors.initials: MW
authors.lastname: Lenders
authors.forename: M Fiorella
authors.initials: MF
authors.lastname: Contarino
authors.forename: Marieke S J
authors.initials: MS
authors.lastname: Mink
authors.forename: Lo J
authors.initials: LJ
authors.lastname: Bour
authors.forename: Pepijn
authors.initials: P
authors.lastname: van den Munckhof
authors.forename: Ben A
authors.initials: BA
authors.lastname: Schmand
authors.forename: Rob J
authors.initials: RJ
authors.lastname: de Haan
authors.forename: P Richard
authors.initials: PR
authors.lastname: Schuurman
authors.forename: Rob M A
authors.initials: RM
authors.lastname: de Bie
mesh_terms: D000368:Aged; D046690:Deep Brain Stimulation / Q000379:methods*; D005260:Female; D005917:Globus Pallidus / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000473:pathology* / Q000628:therapy*; D012720:Severity of Illness Index; D020531:Subthalamic Nucleus / Q000502:physiology*; D016896:Treatment Outcome