title: The long-term outcome of orthostatic tremor.
abstract: OBJECTIVE
  Orthostatic tremor is a rare condition characterised by high-frequency tremor that appears on standing. Although the essential clinical features of orthostatic tremor are well established, little is known about the natural progression of the disorder. We report the long-term outcome based on the largest multicentre cohort of patients with orthostatic tremor.
  
  
  METHODS
  Clinical information of 68 patients with clinical and electrophysiological diagnosis of orthostatic tremor and a minimum follow-up of 5 years is presented.
  
  
  RESULTS
  There was a clear female preponderance (76.5%) with a mean age of onset at 54 years. Median follow-up was 6 years (range 5-25). On diagnosis, 86.8% of patients presented with isolated orthostatic tremor and 13.2% had additional neurological features. At follow-up, seven patients who initially had isolated orthostatic tremor later developed further neurological signs. A total 79.4% of patients reported worsening of orthostatic tremor symptoms. These patients had significantly longer symptom duration than those without reported worsening (median 15.5 vs 10.5 years, respectively; p=0.005). There was no change in orthostatic tremor frequency over time. Structural imaging was largely unremarkable and dopaminergic neuroimaging (DaTSCAN) was normal in 18/19 cases. Pharmacological treatments were disappointing. Two patients were treated surgically and showed improvement.
  
  
  CONCLUSIONS
  Orthostatic tremor is a progressive disorder with increased disability although tremor frequency is unchanged over time. In most cases, orthostatic tremor represents an isolated syndrome. Drug treatments are unsatisfactory but surgery may hold promise.
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London, UK Department of Neurology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany.
authors.forename: Christos
authors.initials: C
authors.lastname: Ganos
authors.affiliation: Department of Neurology, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France CRICM UPMC/INSERM UMR 1127 CNRS UMR7225 Brain and Spine Institute, Paris, France.
authors.forename: Lucie
authors.initials: L
authors.lastname: Maugest
authors.affiliation: CRICM UPMC/INSERM UMR 1127 CNRS UMR7225 Brain and Spine Institute, Paris, France Neurophysiology Unit, AP-HP, Saint-Antoine Hospital, Paris, France Pierre Marie Curie Paris-6 University, Paris, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Apartis
authors.affiliation: Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, University Health Network, Toronto, Canada.
authors.forename: Carmen
authors.initials: C
authors.lastname: Gasca-Salas
authors.affiliation: Unidad de Trastornos del Movimiento, Servicio de Neurología y Neurofisiología Clínica, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.
authors.forename: María T
authors.initials: MT
authors.lastname: Cáceres-Redondo
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London, UK.
authors.forename: Roberto
authors.initials: R
authors.lastname: Erro
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London, UK Department of Neurology, Hospital del Mar, Barcelona, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Navalpotro-Gómez
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London, UK.
authors.forename: Amit
authors.initials: A
authors.lastname: Batla
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London, UK.
authors.forename: Elena
authors.initials: E
authors.lastname: Antelmi
authors.affiliation: Department of Neurology, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France Pierre Marie Curie Paris-6 University, Paris, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Degos
authors.affiliation: Department of Neurology, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France CRICM UPMC/INSERM UMR 1127 CNRS UMR7225 Brain and Spine Institute, Paris, France Pierre Marie Curie Paris-6 University, Paris, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Roze
authors.affiliation: Department of Neurology, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France CRICM UPMC/INSERM UMR 1127 CNRS UMR7225 Brain and Spine Institute, Paris, France Pierre Marie Curie Paris-6 University, Paris, France.
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Welter
authors.affiliation: Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, University Health Network, Toronto, Canada Parkinson's Disease and Movement Disorder Centre, division of Neurology, department of Medicine, University of Ottawa, The Ottawa Hospital, Ottawa, Canada.
authors.forename: Tiago
authors.initials: T
authors.lastname: Mestre
authors.affiliation: Unidad de Trastornos del Movimiento, Servicio de Neurología y Neurofisiología Clínica, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Palomar
authors.affiliation: Department of Medicine, University of Toronto, Toronto, Canada Division of Brain, Imaging and Behavior-Systems Neuroscience, Toronto Western Research Institute, Toronto, Canada.
authors.forename: Reina
authors.initials: R
authors.lastname: Isayama
authors.affiliation: Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, University Health Network, Toronto, Canada Department of Medicine, University of Toronto, Toronto, Canada Division of Brain, Imaging and Behavior-Systems Neuroscience, Toronto Western Research Institute, Toronto, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Chen
authors.affiliation: Department of Clinical Neurophysiology, National Hospital for Neurology and Neurosurgery, London, UK.
authors.forename: Carla
authors.initials: C
authors.lastname: Cordivari
authors.affiliation: Unidad de Trastornos del Movimiento, Servicio de Neurología y Neurofisiología Clínica, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain.
authors.forename: Pablo
authors.identifier: http://orcid.org/0000-0003-1656-302X
authors.initials: P
authors.lastname: Mir
authors.affiliation: Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, University Health Network, Toronto, Canada.
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Lang
authors.affiliation: Morton and Gloria Shulman Movement Disorders Clinic and the Edmond J. Safra Program in Parkinson's Disease, University Health Network, Toronto, Canada.
authors.forename: Susan H
authors.initials: SH
authors.lastname: Fox
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London, UK.
authors.forename: Kailash P
authors.initials: KP
authors.lastname: Bhatia
authors.affiliation: Department of Neurology, AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Paris, France CRICM UPMC/INSERM UMR 1127 CNRS UMR7225 Brain and Spine Institute, Paris, France Pierre Marie Curie Paris-6 University, Paris, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Vidailhet
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D018450:Disease Progression; D059290:Dopaminergic Neurons; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging; D019635:Neurosurgical Procedures / Q000379:methods; D012737:Sex Factors; D062187:Spinal Cord Stimulation; D016896:Treatment Outcome; D014202:Tremor / Q000188:drug therapy / Q000453:epidemiology* / Q000628:therapy*
keywords: MOVEMENT DISORDERS; TREMOR