title: Functional assessment and quality of life in essential tremor with bilateral or unilateral DBS and focused ultrasound thalamotomy.
abstract: BACKGROUND
  Thalamic deep brain stimulation (DBS) has largely replaced radiofrequency thalamotomy as the treatment of choice for disabling, medication-refractory essential tremor. Recently, the development of transcranial, high-intensity focused ultrasound has renewed interest in thalamic lesioning. The purpose of this study is to compare functional outcomes and quality of life in essential tremor patients treated with either bilateral Vim DBS or unilateral procedures (focused ultrasound or DBS). We hypothesized that all three would effectively treat the dominant hand and positively impact functional outcomes and quality of life as measured with the Clinical Rating Scale for Tremor and the Quality of Life in Essential Tremor Questionnaire.
  
  
  METHODS
  This is a retrospective study of medication-refractory essential tremor patients treated at the University of Virginia with bilateral Vim DBS (n = 57), unilateral Vim DBS (n = 13), or unilateral focused ultrasound Vim thalamotomy (n = 15). Tremor was rated for all patients before and after treatment, using the Clinical Rating Scale for Tremor and Quality of Life in Essential Tremor Questionnaire.
  
  
  RESULTS
  Patients undergoing bilateral DBS treatment had more baseline tremor and worse quality of life scores. Patients had significant improvements in tremor symptoms and quality of life with all three treatments. Both DBS procedures improved axial tremor. No difference was seen in the degree of improvement in upper extremity tremor score, disability, or overall quality of life between bilateral and either unilateral procedure.
  
  
  CONCLUSIONS
  Bilateral thalamic DBS improves overall tremor more than unilateral DBS or focused ultrasound treatment; however, unilateral treatments are equally effective in treating contralateral hand tremor. Despite the greater overall tremor reduction with bilateral DBS, there is no difference in disability or quality of life comparing bilateral versus unilateral treatments.
authors.affiliation: Department of Physical Therapy, University of Virginia HealthSystem, Charlottesville, Virginia, USA.
authors.forename: Diane S
authors.initials: DS
authors.lastname: Huss
authors.affiliation: Department of Neurosurgery, University of Virginia HealthSystem, Charlottesville, Virginia, USA.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Dallapiazza
authors.affiliation: Department of Neurology, University of Virginia HealthSystem, Charlottesville, Virginia, USA.
authors.forename: Binit B
authors.initials: BB
authors.lastname: Shah
authors.affiliation: Department of Neurology, University of Virginia HealthSystem, Charlottesville, Virginia, USA.
authors.forename: Madaline B
authors.initials: MB
authors.lastname: Harrison
authors.affiliation: School of Medicine, University of Virginia HealthSystem, Charlottesville, Virginia, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Diamond
authors.affiliation: Department of Neurosurgery, University of Virginia HealthSystem, Charlottesville, Virginia, USA.
authors.forename: W Jeff
authors.initials: WJ
authors.lastname: Elias
mesh_terms: D000368:Aged; D046690:Deep Brain Stimulation / Q000379:methods*; D020329:Essential Tremor / Q000175:diagnosis* / Q000523:psychology / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life / Q000523:psychology*; D012189:Retrospective Studies; D013788:Thalamus; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional
keywords: deep brain stimulation; essential tremor; focused ultrasound; quality of life; thalamotomy