title: Onset latency of segmental dystonia after deep brain stimulation cessation: a randomized, double-blind crossover trial.
abstract: BACKGROUND
  Deep brain stimulation (DBS) of the globus pallidus internus is an effective treatment for cervical dystonia (CD). Interestingly, the onset of initial DBS effects is significantly prolonged compared with that in other diseases, such as Parkinson's disease. The return of symptoms after cessation of DBS could be delayed as well, but this has not been studied systematically.
  
  
  METHODS
  In patients who were treated for CD using DBS and had a good treatment effect, we compared interruption of DBS with sham-OFF in a randomized, double-blind crossover trial.
  
  
  RESULTS
  We observed that dystonic features appeared within a few minutes at almost full intensity in all patients after the cessation of DBS.
  
  
  CONCLUSIONS
  The almost immediate onset of dystonic features in our sample seems to exclude mechanisms with long time constants from the pathophysiology of dystonia. Thus, it is likely that, in these patients, an aberrant pattern of neural activity representing an inappropriate set point value for the position of the head is responsible for dystonia.
authors.affiliation: Department of Neurology, Ludwig-Maximilians University Munich, Munich, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Levin
authors.forename: Arun
authors.initials: A
authors.lastname: Singh
authors.forename: Berend
authors.initials: B
authors.lastname: Feddersen
authors.forename: Jan-Hinnerk
authors.initials: JH
authors.lastname: Mehrkens
authors.forename: Kai
authors.initials: K
authors.lastname: Bötzel
mesh_terms: D018592:Cross-Over Studies; D046690:Deep Brain Stimulation / Q000009:adverse effects; D004311:Double-Blind Method; D004421:Dystonia / Q000209:etiology* / Q000503:physiopathology; D004567:Electrodes, Implanted; D005917:Globus Pallidus / Q000502:physiology*; D006801:Humans; D016896:Treatment Outcome
keywords: Toronto Western Spasmodic Torticollis Rating Scale; deep brain stimulation; globus pallidus; segmental dystonia