title: Bilateral pallidal stimulation in children and adolescents with primary generalized dystonia--report of six patients and literature-based analysis of predictive outcomes variables.
abstract: BACKGROUND
  Primary generalized dystonia is a rare movement disorder. Medical treatment rarely relieves symptoms. The aim of this study was to investigate the efficacy and safety of bilateral pallidal stimulation in 6 children and adolescents with primary generalized dystonia. In addition, we strived to find predictors for treatment outcome by review and analysis of previously published studies.
  
  
  METHODS
  Six patients with primary generalized dystonia underwent chronic bilateral stimulation of the globus pallidus internus. A PubMed and MEDLINE search was performed in order to identify children and adolescents who underwent deep brain stimulation for primary generalized dystonia. The primary efficacy endpoint was the relative change of the Burke-Fahn-Marsden-Dystonia-Rating-Scale (movement score) after surgery.
  
  
  RESULTS
  Forty-four patients were found to meet the inclusion criteria. The mean age at onset of the disease was 7.8+/-2.8years and the mean age at surgery was 14.2+/-3.5years. The mean Burke-Fahn-Marsden-Dystonia-Rating-Scale (movement score) was 56.9+/-22.7 before surgery and 23.7+/-23.2 at a mean follow up of 13.0+/-4.8months (p<0.001). The improvement in the DYT1-positive group was significantly higher compared to the DYT1-negative group (77%+/-24% and 44%+/-30%, respectively, p<0.001). A positive correlation between the movement score before and after surgery was found in both the DYT1-positive and DYT1-negative cohort (rs=0.624, p<0.001 and rs=0.734, p<0.001, respectively).
  
  
  CONCLUSIONS
  DBS is an effective treatment in children and adolescents with primary generalized dystonia. Predictive factors for a better treatment outcome are DYT1-positive status and minor motor impairment before surgery.
authors.affiliation: Department of Pediatric Neurology and Developmental Medicine, Dr. von Hauner's Children's Hospital, Ludwig-Maximilians-University, Lindwurm Street 4, 80337 Munich, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Borggraefe
authors.forename: Jan Hinnerk
authors.initials: JH
authors.lastname: Mehrkens
authors.forename: Mila
authors.initials: M
authors.lastname: Telegravciska
authors.forename: Steffen
authors.initials: S
authors.lastname: Berweck
authors.forename: Kai
authors.initials: K
authors.lastname: Bötzel
authors.forename: Florian
authors.initials: F
authors.lastname: Heinen
mesh_terms: D000293:Adolescent; D002648:Child; D046690:Deep Brain Stimulation / Q000379:methods*; D020821:Dystonic Disorders / Q000628:therapy*; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D005917:Globus Pallidus / Q000502:physiology*; D006801:Humans; D016239:MEDLINE / Q000706:statistics & numerical data; D008297:Male; D017063:Outcome Assessment, Health Care; D039781:PubMed / Q000706:statistics & numerical data; D012720:Severity of Illness Index; D013223:Statistics as Topic; D018709:Statistics, Nonparametric; D055815:Young Adult