title: Deep brain stimulation of the ventral intermediate nucleus of the thalamus in medically refractory orthostatic tremor: preliminary observations.
abstract: Orthostatic tremor (OT) is a disabling movement disorder associated with postural and gait impairment in the elderly. Medical therapy often yields insufficient benefit. We report the clinical and electrophysiological data on two patients with medication-refractory OT treated with deep brain stimulation of the ventral intermediate thalamic nucleus (Vim DBS). Patient 1 underwent bilateral deep brain stimulation (DBS) and Patient 2 unilateral Vim DBS following 28 and 30 years of disease duration, respectively. Both patients showed increased latency to symptom onset after rising from a seated position, improved tolerance for prolonged standing, and slower crescendo of tremor severity when remaining upright. Postoperative evaluation demonstrated decreased amplitude of electromyographic activity with persistence of well-defined oscillatory behavior showing strong coherence at 15 Hz between all muscles tested in the upper and lower limbs. Postural sway was unchanged. Clinical benefits have been sustained for over 18 months in Patient 1, and receded after 3 months in Patient 2. These findings support the consideration of bilateral Vim DBS implantation as a therapeutic option in patients with medically refractory OT. Further efficacy studies on chronic stimulation to disrupt the abnormal oscillatory activity in this disorder are warranted.
authors.affiliation: Department of Neurology, The Neuroscience Institute, Movement Disorders Center, University of Cincinnati, Cincinnati, Ohio 45267-0525, USA. alberto.espay@uc.edu
authors.forename: Alberto J
authors.initials: AJ
authors.lastname: Espay
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Duker
authors.forename: Robert
authors.initials: R
authors.lastname: Chen
authors.forename: Michael S
authors.initials: MS
authors.lastname: Okun
authors.forename: Edwin T
authors.initials: ET
authors.lastname: Barrett
authors.forename: Johnna
authors.initials: J
authors.lastname: Devoto
authors.forename: Pamela
authors.initials: P
authors.lastname: Zeilman
authors.forename: Maureen
authors.initials: M
authors.lastname: Gartner
authors.forename: Noël
authors.initials: N
authors.lastname: Burton
authors.forename: Helard A
authors.initials: HA
authors.lastname: Miranda
authors.forename: George T
authors.initials: GT
authors.lastname: Mandybur
authors.forename: Theresa A
authors.initials: TA
authors.lastname: Zesiewicz
authors.forename: Kelly D
authors.initials: KD
authors.lastname: Foote
authors.forename: Fredy J
authors.initials: FJ
authors.lastname: Revilla