title: Prevalence and characteristics of tremor in the NARCOMS multiple sclerosis registry: a cross-sectional survey.
abstract: OBJECTIVE
  (1)To describe the prevalence and severity of tremor in patients with multiple sclerosis (MS) registered within a large North American MS registry; (2) to provide detailed descriptions on the characteristics and severity of tremor in a subset of registrants and (3) to compare several measures of tremor severity for strength of agreement.
  
  
  METHODS
  The North American Research Committee on MS (NARCOMS) registry.
  
  
  METHODS
  Registrants of NARCOMS reporting mild or greater tremor severity.
  
  
  METHODS
  We determined the cross-sectional prevalence of tremor in the NARCOMS registry over three semiannual updates between fall 2010 and fall 2011. A subset of registrants (n=552) completed a supplemental survey providing detailed descriptions of their tremor. Outcomes included descriptive characteristics of their tremors and correlations between outcome measures to determine the strength of agreement in assessing tremor severity.
  
  
  RESULTS
  The estimated prevalence of tremor in NARCOMS ranged from 45% to 46.8%, with severe tremor affecting 5.5-5.9% of respondents. In the subset completing the supplemental survey, mild tremor severity was associated with younger age of MS diagnosis and tremor onset than those with moderate or severe tremor. However, tremor severity did not differ by duration of disease or tremor. Respondents provided descriptions of tremor symptoms on the Clinical Ataxia Rating Scale, which had a moderate to good (ρ=0.595) correlation with the Tremor Related Activities of Daily Living (TRADL) scale. Objectively scored Archimedes' spirals had a weaker (ρ=0.358) correlation with the TRADL. Rates of unemployment, disability and symptomatic medication use increased with tremor severity, but were high even among those with mild tremor.
  
  
  CONCLUSIONS
  Tremor is common among NARCOMS registrants and severely disabling for some. Both ADL-based and symptom-descriptive measures of tremor severity can be used to stratify patients.
authors.affiliation: Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama, USA Birmingham VA Medical Center, Birmingham, Alabama, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Rinker
authors.affiliation: Department of Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Amber R
authors.initials: AR
authors.lastname: Salter
authors.affiliation: Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Harrison
authors.initials: H
authors.lastname: Walker
authors.affiliation: Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Amara
authors.affiliation: Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: William
authors.initials: W
authors.lastname: Meador
authors.affiliation: Department of Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Gary R
authors.initials: GR
authors.lastname: Cutter
mesh_terms: D000203:Activities of Daily Living; D000367:Age Factors; D000368:Aged; D001259:Ataxia / Q000209:etiology; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications*; D017063:Outcome Assessment, Health Care; D015995:Prevalence; D012042:Registries; D012106:Research; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014202:Tremor / Q000188:drug therapy / Q000453:epidemiology* / Q000209:etiology; D014478:Unemployment
keywords: EPIDEMIOLOGY