title: Impaired force control in writer's cramp showing a bilateral deficit in sensorimotor integration.
abstract: BACKGROUND
  Abnormal cortical processing of sensory inputs has been found bilaterally in writer's cramp (WC). This study tested the hypothesis that patients with WC have an impaired ability to adjust grip forces according to visual and somatosensory cues in both hands.
  
  
  METHODS
  A unimanual visuomotor force-tracking task and a bimanual sense of effort force-matching task were performed by WC patients and healthy controls.
  
  
  RESULTS
  In visuomotor tracking, WC patients showed increased error, greater variability, and longer release duration than controls. In the force-matching task, patients underestimated, whereas controls overestimated, the force applied in the other hand. Visuomotor tracking and force matching were equally impaired in both the symptomatic and nonsymptomatic hand in WC patients.
  
  
  CONCLUSIONS
  This study provides evidence of bilaterally impaired grip-force control in WC, when using visual or sense of effort cues. This suggests a generalized subclinical deficit in sensorimotor integration in WC.
authors.affiliation: INSERM U894, Université Paris Descartes, Service de Neurologie, Hôpital Sainte-Anne, Paris, France; CNRS UMR 7287, Aix-Marseille Université, Marseille, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Bleton
authors.forename: Maxime
authors.initials: M
authors.lastname: Teremetz
authors.forename: Marie
authors.initials: M
authors.lastname: Vidailhet
authors.forename: Serge
authors.initials: S
authors.lastname: Mesure
authors.forename: Marc A
authors.initials: MA
authors.lastname: Maier
authors.forename: Påvel G
authors.initials: PG
authors.lastname: Lindberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020821:Dystonic Disorders / Q000503:physiopathology*; D005260:Female; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance / Q000502:physiology*; D055815:Young Adult
keywords: basal ganglia; force control; sensorimotor feedback; writer's cramp