title: Bilateral deep brain stimulation of the globus pallidus to treat tardive dyskinesia.
abstract: BACKGROUND
  Tardive dyskinesia (TD) is a common and potentially disabling disorder induced by use of antipsychotic drugs for which medical treatment often gives disappointing results.
  
  
  OBJECTIVE
  To assess the efficacy of bilateral deep brain stimulation of the internal part of the globus pallidus to treat severe TD.
  
  
  METHODS
  Prospective phase 2 multicenter study.
  
  
  METHODS
  Six French university hospitals. Patients Patients with severe TD refractory to medical treatment were studied to evaluate the severity of abnormal involuntary movements before and after 6 months of bilateral globus pallidus deep brain stimulation. A 2-step open Fleming procedure was used to avoid unnecessary accrual of patients. A successful outcome was defined as a decrease of more than 40% in the main outcome measure at 6 months. The early stopping rule was invoked if the number of successful outcomes in 10 patients was fewer than 2, or 5 or more. A double-blind evaluation in the presence and absence of stimulation was performed at 6 months after surgery. Main Outcome Measure Change in score on the Extrapyramidal Symptoms Rating Scale.
  
  
  RESULTS
  At 6 months after surgery, the Extrapyramidal Symptoms Rating Scale score had decreased compared with baseline by more than 40% (mean improvement, 61%; range, 44%-75%) in the first 10 patients included. In accord with the 2-step open Fleming procedure, we ended the trial at the first step and concluded that pallidal stimulation is an effective treatment for TD. The efficacy of the treatment was confirmed by a double-blind evaluation, with a mean decrease of 50% (range, 30%-66%) (P = .002) in the Extrapyramidal Symptoms Rating Scale score when stimulation was applied compared with the absence of stimulation. There were no marked changes in the patients' psychiatric status.
  
  
  CONCLUSIONS
  Although these results need to be confirmed in a larger group of patients with a longer follow-up, bilateral globus pallidus deep brain stimulation seems to offer a much-needed new treatment option for disabling TD.
authors.affiliation: Centre Hospitalier Universitaire de Nantes, Centre d'Investigation Clinique, Nantes, France. philippe.damier@chu-nantes.fr
authors.forename: Philippe
authors.initials: P
authors.lastname: Damier
authors.forename: Stéphane
authors.initials: S
authors.lastname: Thobois
authors.forename: Tatiana
authors.initials: T
authors.lastname: Witjas
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Cuny
authors.forename: Philippe
authors.initials: P
authors.lastname: Derost
authors.forename: Sylvie
authors.initials: S
authors.lastname: Raoul
authors.forename: Patrick
authors.initials: P
authors.lastname: Mertens
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Peragut
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Lemaire
authors.forename: Pierre
authors.initials: P
authors.lastname: Burbaud
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Nguyen
authors.forename: Pierre-Michel
authors.initials: PM
authors.lastname: Llorca
authors.forename: Olivier
authors.initials: O
authors.lastname: Rascol
mesh_terms: D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000009:adverse effects; D001480:Basal Ganglia Diseases / Q000175:diagnosis / Q000209:etiology; D046690:Deep Brain Stimulation / Q000009:adverse effects / Q000379:methods*; D003866:Depressive Disorder / Q000188:drug therapy; D004311:Double-Blind Method; D004409:Dyskinesia, Drug-Induced / Q000209:etiology / Q000601:surgery / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality / Q000502:physiology; D005917:Globus Pallidus / Q000502:physiology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012720:Severity of Illness Index; D013238:Stereotaxic Techniques; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents