title: Unilateral cerebellothalamic tract ablation in essential tremor by MRI-guided focused ultrasound.
abstract: OBJECTIVE
  To report results of a prospective trial of unilateral transcranial MRI-guided focused ultrasound (MRIgFUS) ablation of the cerebellothalamic tract in essential tremor (ET).
  
  
  METHODS
  This was a prospective, uncontrolled, single-center interventional study. Patients with ET fulfilling criteria for interventional therapy received unilateral ablation of the cerebellothalamic tract (CTT) by MRIgFUS. Motor symptoms, manual dexterity, cognition, and quality of life were assessed before intervention and at 48 hours and 1, 3, and 6 months after intervention. Rating of standardized video recordings was blinded for evaluation time points. Primary outcome was the change in unilateral hand tremor score of the treated hand.
  
  
  RESULTS
  Six patients received MRIgFUS ablation of the CTT contralateral to the treated hand. Repeated-measures comparison determined a statistically significant 83% reduction (before vs 6 months after intervention mean ± SD; absolute reduction; 95% confidence interval) in the unilateral treated hand subscore (14.3 ± 4.9 vs 2.5 ± 2.6; 11.8; 8.4-15.2;p< 0.001), while quality of life improved by 52% (50.5 ± 19.4 vs 24.8 ± 11.4; 25.7; 3.5-47.28;p= 0.046). Measures for manual dexterity, attention and coordination, and overall cognition were unchanged. Transient side effects (n = 3) were ipsilateral hand clumsiness and mild gait instability for up to 3 months.
  
  
  CONCLUSIONS
  Unilateral MRIgFUS lesioning of the CTT was highly efficacious in reducing contralateral hand tremor in ET without affecting fine motor function and dexterity over 6 months of follow-up. Adverse effects were mild and transient.
  
  
  METHODS
  This study provides Class IV evidence that for patients with ET, transcranial MRIgFUS ablation of the cerebellothalamic tract improves tremor.
authors.affiliation: From the Departments of Neurology (S.R.S., S.H.-L., N.W., A.L., G.K.) and Neurosurgery (R.B.), Kantonsspital St. Gallen, Switzerland; Sobell Department of Motor Neuroscience and Movement Disorders (S.R.S., K.P.B.), University College London, Institute of Neurology, UK; Institute of Neurology (P.N.), Queen Square, London, UK; and Center for Focused Ultrasound (B.W., E.M.), University of Zurich, Children's Hospital Zurich, Switzerland.
authors.forename: Sebastian R
authors.initials: SR
authors.lastname: Schreglmann
authors.affiliation: From the Departments of Neurology (S.R.S., S.H.-L., N.W., A.L., G.K.) and Neurosurgery (R.B.), Kantonsspital St. Gallen, Switzerland; Sobell Department of Motor Neuroscience and Movement Disorders (S.R.S., K.P.B.), University College London, Institute of Neurology, UK; Institute of Neurology (P.N.), Queen Square, London, UK; and Center for Focused Ultrasound (B.W., E.M.), University of Zurich, Children's Hospital Zurich, Switzerland.
authors.forename: Ronald
authors.initials: R
authors.lastname: Bauer
authors.affiliation: From the Departments of Neurology (S.R.S., S.H.-L., N.W., A.L., G.K.) and Neurosurgery (R.B.), Kantonsspital St. Gallen, Switzerland; Sobell Department of Motor Neuroscience and Movement Disorders (S.R.S., K.P.B.), University College London, Institute of Neurology, UK; Institute of Neurology (P.N.), Queen Square, London, UK; and Center for Focused Ultrasound (B.W., E.M.), University of Zurich, Children's Hospital Zurich, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Hägele-Link
authors.affiliation: From the Departments of Neurology (S.R.S., S.H.-L., N.W., A.L., G.K.) and Neurosurgery (R.B.), Kantonsspital St. Gallen, Switzerland; Sobell Department of Motor Neuroscience and Movement Disorders (S.R.S., K.P.B.), University College London, Institute of Neurology, UK; Institute of Neurology (P.N.), Queen Square, London, UK; and Center for Focused Ultrasound (B.W., E.M.), University of Zurich, Children's Hospital Zurich, Switzerland.
authors.forename: Kailash P
authors.initials: KP
authors.lastname: Bhatia
authors.affiliation: From the Departments of Neurology (S.R.S., S.H.-L., N.W., A.L., G.K.) and Neurosurgery (R.B.), Kantonsspital St. Gallen, Switzerland; Sobell Department of Motor Neuroscience and Movement Disorders (S.R.S., K.P.B.), University College London, Institute of Neurology, UK; Institute of Neurology (P.N.), Queen Square, London, UK; and Center for Focused Ultrasound (B.W., E.M.), University of Zurich, Children's Hospital Zurich, Switzerland.
authors.forename: Parashkev
authors.initials: P
authors.lastname: Natchev
authors.affiliation: From the Departments of Neurology (S.R.S., S.H.-L., N.W., A.L., G.K.) and Neurosurgery (R.B.), Kantonsspital St. Gallen, Switzerland; Sobell Department of Motor Neuroscience and Movement Disorders (S.R.S., K.P.B.), University College London, Institute of Neurology, UK; Institute of Neurology (P.N.), Queen Square, London, UK; and Center for Focused Ultrasound (B.W., E.M.), University of Zurich, Children's Hospital Zurich, Switzerland.
authors.forename: Nikolas
authors.initials: N
authors.lastname: Wegener
authors.affiliation: From the Departments of Neurology (S.R.S., S.H.-L., N.W., A.L., G.K.) and Neurosurgery (R.B.), Kantonsspital St. Gallen, Switzerland; Sobell Department of Motor Neuroscience and Movement Disorders (S.R.S., K.P.B.), University College London, Institute of Neurology, UK; Institute of Neurology (P.N.), Queen Square, London, UK; and Center for Focused Ultrasound (B.W., E.M.), University of Zurich, Children's Hospital Zurich, Switzerland.
authors.forename: Anita
authors.initials: A
authors.lastname: Lebeda
authors.affiliation: From the Departments of Neurology (S.R.S., S.H.-L., N.W., A.L., G.K.) and Neurosurgery (R.B.), Kantonsspital St. Gallen, Switzerland; Sobell Department of Motor Neuroscience and Movement Disorders (S.R.S., K.P.B.), University College London, Institute of Neurology, UK; Institute of Neurology (P.N.), Queen Square, London, UK; and Center for Focused Ultrasound (B.W., E.M.), University of Zurich, Children's Hospital Zurich, Switzerland.
authors.forename: Beat
authors.initials: B
authors.lastname: Werner
authors.affiliation: From the Departments of Neurology (S.R.S., S.H.-L., N.W., A.L., G.K.) and Neurosurgery (R.B.), Kantonsspital St. Gallen, Switzerland; Sobell Department of Motor Neuroscience and Movement Disorders (S.R.S., K.P.B.), University College London, Institute of Neurology, UK; Institute of Neurology (P.N.), Queen Square, London, UK; and Center for Focused Ultrasound (B.W., E.M.), University of Zurich, Children's Hospital Zurich, Switzerland.
authors.forename: Ernst
authors.initials: E
authors.lastname: Martin
authors.affiliation: From the Departments of Neurology (S.R.S., S.H.-L., N.W., A.L., G.K.) and Neurosurgery (R.B.), Kantonsspital St. Gallen, Switzerland; Sobell Department of Motor Neuroscience and Movement Disorders (S.R.S., K.P.B.), University College London, Institute of Neurology, UK; Institute of Neurology (P.N.), Queen Square, London, UK; and Center for Focused Ultrasound (B.W., E.M.), University of Zurich, Children's Hospital Zurich, Switzerland. georg.kaegi@kssg.ch.
authors.forename: Georg
authors.initials: G
authors.lastname: Kägi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002531:Cerebellum / Q000000981:diagnostic imaging / Q000601:surgery*; D020329:Essential Tremor / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D013788:Thalamus / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome; D014464:Ultrasonic Therapy / Q000379:methods*; D018084:Ultrasonography, Interventional / Q000379:methods*