title: Echoes from childhood--imitation in Gilles de la Tourette Syndrome.
abstract: BACKGROUND
  Tourette syndrome patients are reported to show automatic imitation (echopraxia), but this has not yet been proven experimentally.
  
  
  METHODS
  Video clips showing either tics of other Tourette patients or spontaneous movements of healthy subjects were presented to Tourette patients and healthy subjects. Participants' responses were assessed using blinded review of video recordings by 2 independent raters and related to stimuli presented.
  
  
  RESULTS
  Both raters detected more echoes in patients. In a permutation analysis, no healthy subject had echoes above chance level. In contrast, 6 and 5 patients were classified as echoers according to rater 1 and rater 2, respectively, in 1 analysis, and 9 patients were so classified in a second analysis (according to rater 2 only). Concordance between raters was high. Patients echoed both following stimuli showing tics and following stimuli showing spontaneous movements. Most echoes were part of patients' individual tic repertoire.
  
  
  CONCLUSIONS
  Echopraxia is a hallmark of Tourette syndrome.
authors.affiliation: Institute of Clinical Neuroscience and Medical Psychology, Heinrich-Heine University, Düsseldorf, Germany.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Finis
authors.forename: Agnes
authors.initials: A
authors.lastname: Moczydlowski
authors.forename: Bettina
authors.initials: B
authors.lastname: Pollok
authors.forename: Katja
authors.initials: K
authors.lastname: Biermann-Ruben
authors.forename: Götz
authors.initials: G
authors.lastname: Thomalla
authors.forename: Martin
authors.initials: M
authors.lastname: Heil
authors.forename: Holger
authors.initials: H
authors.lastname: Krause
authors.forename: Melanie
authors.initials: M
authors.lastname: Jonas
authors.forename: Alfons
authors.initials: A
authors.lastname: Schnitzler
authors.forename: Alexander
authors.initials: A
authors.lastname: Münchau
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007100:Imitative Behavior / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D018709:Statistics, Nonparametric; D005879:Tourette Syndrome / Q000503:physiopathology*; D014743:Videotape Recording / Q000379:methods; D055815:Young Adult