title: A prospective single-blind study of Gamma Knife thalamotomy for tremor.
abstract: OBJECTIVE
  To evaluate the safety and efficacy of unilateral Gamma Knife thalamotomy (GKT) for treatment of severe tremor with a prospective blinded assessment.
  
  
  METHODS
  Fifty patients (mean age: 74.5 years; 32 men) with severe refractory tremor (36 essential, 14 parkinsonian) were treated with unilateral GKT. Targeting of the ventral intermediate nucleus (Vim) was achieved with Leksell Gamma Knife with a single shot through a 4-mm collimator helmet. The prescription dose was 130 Gy. Neurologic and neuropsychological assessments including a single-blinded video assessment of the tremor severity performed by a movement disorders neurologist from another center were performed before and 12 months after treatment. MRI follow-up occurred at 3, 6, and 12 months.
  
  
  RESULTS
  The upper limb tremor score improved by 54.2% on the blinded assessment (p < 0.0001). All tremor components (rest, postural, and intention) were improved. Activities of daily living were improved by 72.2%. Cognitive functions remained unchanged. Following GKT, the median delay of improvement was 5.3 months (range 1-12 months). The only side effect was a transient hemiparesis associated with excessive edema around the thalamotomy in one patient.
  
  
  CONCLUSIONS
  This blinded prospective assessment demonstrates that unilateral GKT is a safe and efficient procedure for severe medically refractory tremor. Side effects were rare and transient in this study.
  
  
  METHODS
  This study provides Class IV evidence that for patients with severe refractory tremor, GKT is well tolerated and effective in reducing tremor impairment.
authors.affiliation: From the Department of Neurology and Movement Disorders (T.W., A.E., J.P.A.) and Department of Functional and Stereotactic Neurosurgery and Radiosurgery (R.C., J.R.), Assistance Publique-Hôpitaux de Marseille, Aix-Marseille Université, Timone University Hospital; Institut de Neurosciences de la Timone (T.W., A.E., J.P.A.), UMR 7289, CNRS Aix-Marseille Université, Marseille, France; Université Grenoble Alpes (P.K.), GIN INSERM U318 and CHU de Grenoble, Movement Disorder Unit, Grenoble, France; CNRS-Aix-Marseille Université (M.V.), Laboratory of Cognitive Neurosciences, FR 3 C, Marseille, France; Unit of Functional Neurosurgery (M.H.), UCL Institute of Neurology, Queen Square, London, UK; Department of Clinical Neuroscience (M.H.), Umeå University, Sweden; and INSERM (R.C., J.R.), UMR 1106, Aix-Marseille Université, Marseille, France. tatiana.witjas@ap-hm.fr.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Witjas
authors.affiliation: From the Department of Neurology and Movement Disorders (T.W., A.E., J.P.A.) and Department of Functional and Stereotactic Neurosurgery and Radiosurgery (R.C., J.R.), Assistance Publique-Hôpitaux de Marseille, Aix-Marseille Université, Timone University Hospital; Institut de Neurosciences de la Timone (T.W., A.E., J.P.A.), UMR 7289, CNRS Aix-Marseille Université, Marseille, France; Université Grenoble Alpes (P.K.), GIN INSERM U318 and CHU de Grenoble, Movement Disorder Unit, Grenoble, France; CNRS-Aix-Marseille Université (M.V.), Laboratory of Cognitive Neurosciences, FR 3 C, Marseille, France; Unit of Functional Neurosurgery (M.H.), UCL Institute of Neurology, Queen Square, London, UK; Department of Clinical Neuroscience (M.H.), Umeå University, Sweden; and INSERM (R.C., J.R.), UMR 1106, Aix-Marseille Université, Marseille, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Carron
authors.affiliation: From the Department of Neurology and Movement Disorders (T.W., A.E., J.P.A.) and Department of Functional and Stereotactic Neurosurgery and Radiosurgery (R.C., J.R.), Assistance Publique-Hôpitaux de Marseille, Aix-Marseille Université, Timone University Hospital; Institut de Neurosciences de la Timone (T.W., A.E., J.P.A.), UMR 7289, CNRS Aix-Marseille Université, Marseille, France; Université Grenoble Alpes (P.K.), GIN INSERM U318 and CHU de Grenoble, Movement Disorder Unit, Grenoble, France; CNRS-Aix-Marseille Université (M.V.), Laboratory of Cognitive Neurosciences, FR 3 C, Marseille, France; Unit of Functional Neurosurgery (M.H.), UCL Institute of Neurology, Queen Square, London, UK; Department of Clinical Neuroscience (M.H.), Umeå University, Sweden; and INSERM (R.C., J.R.), UMR 1106, Aix-Marseille Université, Marseille, France.
authors.forename: Paul
authors.initials: P
authors.lastname: Krack
authors.affiliation: From the Department of Neurology and Movement Disorders (T.W., A.E., J.P.A.) and Department of Functional and Stereotactic Neurosurgery and Radiosurgery (R.C., J.R.), Assistance Publique-Hôpitaux de Marseille, Aix-Marseille Université, Timone University Hospital; Institut de Neurosciences de la Timone (T.W., A.E., J.P.A.), UMR 7289, CNRS Aix-Marseille Université, Marseille, France; Université Grenoble Alpes (P.K.), GIN INSERM U318 and CHU de Grenoble, Movement Disorder Unit, Grenoble, France; CNRS-Aix-Marseille Université (M.V.), Laboratory of Cognitive Neurosciences, FR 3 C, Marseille, France; Unit of Functional Neurosurgery (M.H.), UCL Institute of Neurology, Queen Square, London, UK; Department of Clinical Neuroscience (M.H.), Umeå University, Sweden; and INSERM (R.C., J.R.), UMR 1106, Aix-Marseille Université, Marseille, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Eusebio
authors.affiliation: From the Department of Neurology and Movement Disorders (T.W., A.E., J.P.A.) and Department of Functional and Stereotactic Neurosurgery and Radiosurgery (R.C., J.R.), Assistance Publique-Hôpitaux de Marseille, Aix-Marseille Université, Timone University Hospital; Institut de Neurosciences de la Timone (T.W., A.E., J.P.A.), UMR 7289, CNRS Aix-Marseille Université, Marseille, France; Université Grenoble Alpes (P.K.), GIN INSERM U318 and CHU de Grenoble, Movement Disorder Unit, Grenoble, France; CNRS-Aix-Marseille Université (M.V.), Laboratory of Cognitive Neurosciences, FR 3 C, Marseille, France; Unit of Functional Neurosurgery (M.H.), UCL Institute of Neurology, Queen Square, London, UK; Department of Clinical Neuroscience (M.H.), Umeå University, Sweden; and INSERM (R.C., J.R.), UMR 1106, Aix-Marseille Université, Marseille, France.
authors.forename: Marianne
authors.initials: M
authors.lastname: Vaugoyeau
authors.affiliation: From the Department of Neurology and Movement Disorders (T.W., A.E., J.P.A.) and Department of Functional and Stereotactic Neurosurgery and Radiosurgery (R.C., J.R.), Assistance Publique-Hôpitaux de Marseille, Aix-Marseille Université, Timone University Hospital; Institut de Neurosciences de la Timone (T.W., A.E., J.P.A.), UMR 7289, CNRS Aix-Marseille Université, Marseille, France; Université Grenoble Alpes (P.K.), GIN INSERM U318 and CHU de Grenoble, Movement Disorder Unit, Grenoble, France; CNRS-Aix-Marseille Université (M.V.), Laboratory of Cognitive Neurosciences, FR 3 C, Marseille, France; Unit of Functional Neurosurgery (M.H.), UCL Institute of Neurology, Queen Square, London, UK; Department of Clinical Neuroscience (M.H.), Umeå University, Sweden; and INSERM (R.C., J.R.), UMR 1106, Aix-Marseille Université, Marseille, France.
authors.forename: Marwan
authors.initials: M
authors.lastname: Hariz
authors.affiliation: From the Department of Neurology and Movement Disorders (T.W., A.E., J.P.A.) and Department of Functional and Stereotactic Neurosurgery and Radiosurgery (R.C., J.R.), Assistance Publique-Hôpitaux de Marseille, Aix-Marseille Université, Timone University Hospital; Institut de Neurosciences de la Timone (T.W., A.E., J.P.A.), UMR 7289, CNRS Aix-Marseille Université, Marseille, France; Université Grenoble Alpes (P.K.), GIN INSERM U318 and CHU de Grenoble, Movement Disorder Unit, Grenoble, France; CNRS-Aix-Marseille Université (M.V.), Laboratory of Cognitive Neurosciences, FR 3 C, Marseille, France; Unit of Functional Neurosurgery (M.H.), UCL Institute of Neurology, Queen Square, London, UK; Department of Clinical Neuroscience (M.H.), Umeå University, Sweden; and INSERM (R.C., J.R.), UMR 1106, Aix-Marseille Université, Marseille, France.
authors.forename: Jean Philippe
authors.initials: JP
authors.lastname: Azulay
authors.affiliation: From the Department of Neurology and Movement Disorders (T.W., A.E., J.P.A.) and Department of Functional and Stereotactic Neurosurgery and Radiosurgery (R.C., J.R.), Assistance Publique-Hôpitaux de Marseille, Aix-Marseille Université, Timone University Hospital; Institut de Neurosciences de la Timone (T.W., A.E., J.P.A.), UMR 7289, CNRS Aix-Marseille Université, Marseille, France; Université Grenoble Alpes (P.K.), GIN INSERM U318 and CHU de Grenoble, Movement Disorder Unit, Grenoble, France; CNRS-Aix-Marseille Université (M.V.), Laboratory of Cognitive Neurosciences, FR 3 C, Marseille, France; Unit of Functional Neurosurgery (M.H.), UCL Institute of Neurology, Queen Square, London, UK; Department of Clinical Neuroscience (M.H.), Umeå University, Sweden; and INSERM (R.C., J.R.), UMR 1106, Aix-Marseille Université, Marseille, France.
authors.forename: Jean
authors.initials: J
authors.lastname: Régis
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D020329:Essential Tremor / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications; D011446:Prospective Studies; D016634:Radiosurgery; D012720:Severity of Illness Index; D016037:Single-Blind Method; D013788:Thalamus / Q000601:surgery; D016896:Treatment Outcome; D014202:Tremor / Q000209:etiology / Q000601:surgery*; D020651:Ventral Thalamic Nuclei / Q000601:surgery*