title: Cervical and ocular vestibular evoked potentials in Machado-Joseph disease: Functional involvement of otolith pathways.
abstract: BACKGROUND
  Machado-Joseph disease is defined as an autosomal dominant ataxic disorder caused by degeneration of the cerebellum and its connections and is associated with a broad range of clinical symptoms. The involvement of the vestibular system is responsible for several symptoms and signs observed in the individuals affected by the disease. We measured cervical and ocular vestibular evoked myogenic potentials in a sample of Machado-Joseph disease patients in order to assess functional pathways involved.
  
  
  METHODS
  Bilateral measures of cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP) were obtained from 14 symptomatic patients with genetically proven Machado-Joseph disease and compared with those from a control group of 20 healthy subjects.
  
  
  RESULTS
  Thirteen (93%) patients showed at least one abnormal test result; oVEMP and cVEMP responses were absent in 17/28 (61%) and 11/28 (39%) measures, respectively; and prolonged latency of cVEMP was found in 3/28 (11%) measures. Of the 13 patients with abnormal responses, 9/13 (69%) patients showed discordant abnormal responses: four with absent oVEMP and present cVEMP, two with absent cVEMP and present oVEMP, and three showed unilateral prolonged cVEMP latencies.
  
  
  CONCLUSIONS
  Both otolith-related vestibulocollic and vestibulo-ocular pathways are severely affected in Machado-Joseph disease patients evaluated by VEMPs.
authors.affiliation: Clinical Neurophysiology Unit, Department of Neurology, Universidade Federal de São Paulo (UNIFESP-EPM), São Paulo, Brazil.
authors.forename: Rodrigo Souza
authors.initials: RS
authors.lastname: Ribeiro
authors.affiliation: Clinical Neurophysiology Unit, Department of Neurology, Universidade Federal de São Paulo (UNIFESP-EPM), São Paulo, Brazil.
authors.forename: Melissa Marques
authors.initials: MM
authors.lastname: Pereira
authors.affiliation: Ataxia Unit, Department of Neurology, Universidade Federal de São Paulo (UNIFESP-EPM), São Paulo, Brazil. Electronic address: jlpedroso.neuro@gmail.com.
authors.forename: José Luiz
authors.initials: JL
authors.lastname: Pedroso
authors.affiliation: Ataxia Unit, Department of Neurology, Universidade Federal de São Paulo (UNIFESP-EPM), São Paulo, Brazil; Center of Health Sciences, Universidade Estadual do Ceará, Brazil.
authors.forename: Pedro
authors.initials: P
authors.lastname: Braga-Neto
authors.affiliation: Ataxia Unit, Department of Neurology, Universidade Federal de São Paulo (UNIFESP-EPM), São Paulo, Brazil.
authors.forename: Orlando Graziani Povoas
authors.initials: OG
authors.lastname: Barsottini
authors.affiliation: Clinical Neurophysiology Unit, Department of Neurology, Universidade Federal de São Paulo (UNIFESP-EPM), São Paulo, Brazil.
authors.forename: Gilberto Mastrocola
authors.initials: GM
authors.lastname: Manzano
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D017827:Machado-Joseph Disease / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010037:Otolithic Membrane / Q000503:physiopathology*; D058585:Vestibular Evoked Myogenic Potentials / Q000502:physiology*
keywords: MJD; Machado–Joseph disease; Otolith pathways; SCA3; Spinocerebellar ataxia type 3; VEMP; Vestibular evoked myogenic potentials