title: Prevalence and correlates of rest tremor in essential tremor: cross-sectional survey of 831 patients across four distinct cohorts.
abstract: OBJECTIVE
  Essential tremor (ET) is amongst the most commonly encountered neurological disorders. Its hallmark feature is kinetic tremor. However, other tremors may also occur in ET patients, creating considerable diagnostic confusion amongst treating physicians. Hence, characterizing the prevalence and clinical accompaniments of these other tremors is of value. Surprisingly, there are few data on the prevalence of rest tremor in ET patients, and even fewer data on the clinical correlates of such tremor.
  
  
  METHODS
  Eight hundred and thirty-one patients in four distinct settings (population, genetics study, study of environmental epidemiology, brain bank) underwent a detailed videotaped neurological examination that was reviewed by a senior movement disorders neurologist. Rest tremor was evaluated in several positions (seated, standing, lying down).
  
  
  RESULTS
  The prevalence of rest tremor whilst seated or standing was lowest in the population-based setting (1.9%), highest in the brain bank study (46.4%) and intermediate in the remaining two settings (9.6% and 14.7%, respectively). Rest tremor was restricted to the arms and was not observed in the legs. Rest tremor was associated with older age, longer disease duration (in some studies), greater tremor severity and, to some extent, the presence of cranial tremors.
  
  
  CONCLUSIONS
  Rest tremor can be a common clinical feature of ET. Its prevalence is highly dependent on the setting in which patients are evaluated, ranging from as low as 1% to nearly 50%. Rest tremor seems to emerge as a clinical feature with advancing disease. The anatomical substrates for this type of tremor remain unknown at present.
authors: GH Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
authors: E D
authors: ED
authors: Louis
authors: N
authors: N
authors: Hernandez
authors: M
authors: M
authors: Michalec
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D020329:Essential Tremor / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009519:New York City / Q000453:epidemiology; D015995:Prevalence; D014202:Tremor / Q000453:epidemiology*
keywords: clinical; epidemiology; essential tremor; examination; rest tremor