title: Abnormal interhemispheric inhibition in musician's dystonia - Trait or state?
abstract: BACKGROUND
  A clustering of relatives with dystonia has been reported in families with musician's dystonia suggesting a genetic contribution to this disease. The aim of the present study was to determine whether interhemispheric inhibition (IHI) measured with transcranial magnetic stimulation is impaired in healthy family members rendering it a suitable endophenotypic marker for musician's dystonia.
  
  
  METHODS
  Patients with musician's hand dystonia (n = 21), patients with sporadic writer's cramp (n = 15), their healthy family members (n = 27), healthy musicians (n = 12) and healthy non-musicians (n = 12) were included. An extended interview about the family history and musical activity was performed. IHI in both hemispheres was measured using transcranial magnetic stimulation.
  
  
  RESULTS
  A stepwise regression analysis revealed musical activity (p = 0.001) and a family history of dystonia (p = 0.008) but not dystonia per se, age, handedness or gender as relevant factors modulating IHI.
  
  
  CONCLUSIONS
  These data support the notion of a genetic background of musician's hand dystonia and suggests that reduced IHI is a possible endophenotypic marker of this disorder.
authors.affiliation: Department of Paediatric and Adult Movement Disorders and Neuropsychiatry, Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany; Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany. Electronic address: Tobias.baeumer@neuro.uni-luebeck.de.
authors.forename: Tobias
authors.initials: T
authors.lastname: Bäumer
authors.affiliation: Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany; Kurt Singer Institute for Music Physiology and Musicians' Health, Hanns Eisler School of Music Berlin, Charlottenstr. 55, 10117, Berlin, Germany; Interdisciplinary Competence Center Musicians' Medicine, Charité - University Medicine Berlin, Luisenstr. 13, 1. OG, 10117, Berlin, Germany; Department of Neurology, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Schmidt
authors.affiliation: Department of Neurology, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Heldmann
authors.affiliation: Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
authors.forename: Moritz
authors.initials: M
authors.lastname: Landwehr
authors.affiliation: Department of Neurology, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Simmer
authors.affiliation: Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
authors.forename: Diana
authors.initials: D
authors.lastname: Tönniges
authors.affiliation: Department of Neurology, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Münte
authors.affiliation: Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Lohmann
authors.affiliation: Institute of Music Physiology and Musicians' Medicine, Hanover University of Music, Drama and Media, Schiffgraben 48, 30175, Hanover, Germany.
authors.forename: Eckart
authors.initials: E
authors.lastname: Altenmüller
authors.affiliation: Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Klein
authors.affiliation: Department of Paediatric and Adult Movement Disorders and Neuropsychiatry, Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany; Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Münchau
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000503:physiopathology*; D020821:Dystonic Disorders / Q000175:diagnosis* / Q000235:genetics* / Q000503:physiopathology*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D050781:Transcranial Magnetic Stimulation
keywords: Dystonia; Endophenotype; Musicians dystonia; TMS