title: Alcohol challenge and sensitivity to change of the Essential Tremor Rating Assessment Scale.
abstract: BACKGROUND
  The ability of the Essential Tremor (ET) Rating Assessment Scale (TETRAS) to detect changes in tremor severity is unknown.
  
  
  METHODS
  Fifteen adult ET patients received a single oral ethanol dose calculated to reach 0.05 g/dL breath alcohol content (brAC). Effects were investigated independently with accelerometry and TETRAS.
  
  
  RESULTS
  Accelerometry data were log-transformed and a cumulative score logACC(R+L) was calculated. Correlation between logACC(R+L) and TETRAS was significant. TETRAS and accelerometry showed a significant effect of time point using repeated-measures analysis of variance. The difference between baseline and each of the following six time points as well as the correlation of TETRAS with brAC were significant. The calculated minimum detectable change of TETRAS was 8.9% and the effect size was d = 4.75 (95% confidence interval: 3.60-5.90).
  
  
  CONCLUSIONS
  We demonstrated sensitivity to change of the TETRAS performance scale after a therapeutic intervention, which further establishes its potential for use in both clinical and research settings.
authors.affiliation: Human Motor Control Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA; Department of Neurology, Medical University of Vienna, Vienna, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Voller
authors.forename: Emily
authors.initials: E
authors.lastname: Lines
authors.forename: Gayle
authors.initials: G
authors.lastname: McCrossin
authors.forename: Aaron
authors.initials: A
authors.lastname: Artiles
authors.forename: Sule
authors.initials: S
authors.lastname: Tinaz
authors.forename: Codrin
authors.initials: C
authors.lastname: Lungu
authors.forename: Mark
authors.initials: M
authors.lastname: Hallett
authors.forename: Dietrich
authors.initials: D
authors.lastname: Haubenberger
mesh_terms: D000368:Aged; D000438:Alcohols; D020329:Essential Tremor / Q000175:diagnosis*; D000431:Ethanol; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D000438:Alcohols; D000431:Ethanol
keywords: alcohol challenge; assessment scale; clinical rating; essential tremor; validation study