title: Long-term effects of deep brain stimulation for essential tremor with subjective and objective quantification via mailed-in questionnaires.
abstract: BACKGROUND
  Deep brain stimulation (DBS) is a standard treatment for patients with disabling essential tremor. The short-term efficacy rate is well established.
  
  
  OBJECTIVE
  To assess the long-term effects of DBS in our series and evaluate the durability of the effects over time.
  
  
  METHODS
  Eighty-four patients implanted with unilateral or bilateral DBS for essential tremor were asked to complete three mailed-in questionnaires to assess DBS efficacy objectively and subjectively.
  
  
  RESULTS
  Twenty-six patients responded, with a median follow-up of 41 months. Approximately half of the patients had more than 48 months of follow-up. At the time of follow-up, the Tremor Rating Scale was reduced from a mean score of 7 (5-8) to 3 (2-3) with DBS OFF and ON, respectively. Quality of life, measured with a subset of items of the ADL Taxonomy, improved from a mean of 26 (23-33) to 12 (12-14), comparing DBS OFF and ON. No significant differences were seen when comparing efficacy at short- (<12 months), middle- (12-48 months) or long-term (>48 months) follow-ups.
  
  
  CONCLUSIONS
  DBS has long-term efficacy for tremor control. This is associated with sustained benefits in quality of life. The duration of the follow-up was not associated with any significant difference in efficacy.
authors.affiliation: Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA.
authors.forename: Tatiana H
authors.initials: TH
authors.lastname: de Oliveira
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Ginsberg
authors.forename: Scott
authors.initials: S
authors.lastname: Cooper
authors.forename: Amy
authors.initials: A
authors.lastname: Nowacki
authors.forename: Ali
authors.initials: A
authors.lastname: Rezai
authors.forename: Milind
authors.initials: M
authors.lastname: Deogaonkar
authors.forename: Andre G
authors.initials: AG
authors.lastname: Machado
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D003625:Data Collection; D046690:Deep Brain Stimulation / Q000379:methods*; D020329:Essential Tremor / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011379:Prognosis; D011788:Quality of Life; D011795:Surveys and Questionnaires; D013995:Time