title: The occurrence of dystonia in upper-limb multiple sclerosis tremor.
abstract: BACKGROUND
  The pathophysiology of multiple sclerosis (MS) tremor is uncertain with limited phenotypical studies available.
  
  
  OBJECTIVE
  To investigate whether dystonia contributes to MS tremor and its severity.
  
  
  METHODS
  MS patients (n = 54) with and without disabling uni- or bilateral upper limb tremor were recruited (39 limbs per group). We rated tremor severity, writing and Archimedes spiral drawing; cerebellar dysfunction (SARA score); the Global Dystonia Scale (GDS) for proximal and distal upper limbs, dystonic posturing, mirror movements, geste antagoniste, and writer's cramp.
  
  
  RESULTS
  Geste antagoniste, mirror dystonia, and dystonic posturing were more frequent and severe (p < 0.001) and dystonia scores were correlated with tremor severity in tremor compared to non-tremor patients. A 1-unit increase in distal dystonia predicted a 0.52-Bain unit (95% confidence interval (CI) 0.08-0.97), p = 0.022) increase in tremor severity and a 1-unit (95% CI 0.48-1.6, p = 0.001) increase in drawing scores. A 1-unit increase in proximal dystonia predicted 0.93-Bain unit increase (95% CI 0.45-1.41, p < 0.001) in tremor severity and 1.5-units (95% CI 0.62-2.41, p = 0.002) increase in the drawing score. Cerebellar function in the tremor limb and tremor severity was correlated (p < 0.001).
  
  
  CONCLUSIONS
  Upper limb dystonia is common in MS tremor suggesting that MS tremor pathophysiology involves cerebello-pallido-thalamo-cortical network dysfunction.
authors.affiliation: Department of Neurology, Royal/Melbourne Hospital, Australia Melbourne Brain Centre, Department of Medicine at RMH, University of Melbourne, Australia/Centre for Neuroscience, Department of Anatomy and Neuroscience, University of Melbourne, Australia Anneke.vanderwalt@mh.org.au.
authors.forename: A
authors.initials: A
authors.lastname: Van der Walt
authors.affiliation: Department of Neurology, Royal Melbourne Hospital, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Buzzard
authors.affiliation: Department of Neurology, Royal Melbourne Hospital, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Sung
authors.affiliation: Department of Neurology, Royal Melbourne Hospital, Australia.
authors.forename: T
authors.initials: T
authors.lastname: Spelman
authors.affiliation: Centre for Neuroscience, Department of Anatomy and Neuroscience, University of Melbourne, Australia.
authors.forename: S C
authors.initials: SC
authors.lastname: Kolbe
authors.affiliation: Department of Neurology, Royal Melbourne Hospital, Australia/Department of Neurology, Box Hill Hospital, Melbourne, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Marriott
authors.affiliation: Department of Neurology, Royal Melbourne Hospital, Australia/Melbourne Brain Centre, Department of Medicine at RMH, University of Melbourne, Australia.
authors.forename: H
authors.initials: H
authors.lastname: Butzkueven
authors.affiliation: Department of Neurology, Royal Melbourne Hospital, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Evans
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002526:Cerebellar Diseases / Q000150:complications* / Q000175:diagnosis; D004421:Dystonia / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications* / Q000175:diagnosis; D012720:Severity of Illness Index; D014202:Tremor / Q000175:diagnosis / Q000209:etiology*; D034941:Upper Extremity / Q000503:physiopathology*
keywords: Multiple sclerosis; botulinum toxin; case control studies; cerebellar dysfunction; dystonia; tremor