title: Saccade velocity is reduced in presymptomatic spinocerebellar ataxia type 2.
abstract: OBJECTIVE
  A characteristic feature of spinocerebellar ataxia type 2 (SCA2) is saccadic slowing at early disease stages. We sought to determine whether this sign is detectable before clinical manifestation and quantifies the disease progression throughout life in linear fashion.
  
  
  METHODS
  In a specialized ataxia clinic, 54 presymptomatic carriers of SCA2 polyglutamine expansions and 56 relatives without mutation were documented with regard to their maximal saccade velocity (MSV).
  
  
  RESULTS
  Among the control individuals, a significant effect of aging on MSV was observed. After elimination of this age influence through a matched-pair approach, a presymptomatic decrease of MSV could be shown. The MSV reduction was stronger in carriers of large expansions. In the years before calculated disease manifestation, the MSV impairment advanced insidiously.
  
  
  CONCLUSIONS
  Saccade velocity is a sensitive SCA2 endophenotype that reflects early pontine degeneration and may be a useful diagnostic parameter before the onset of ataxia.
  
  
  CONCLUSIONS
  Future neuroprotective therapies of polyglutamine neurodegeneration may be assessed by MSV from earliest to prefinal disease stages.
authors.affiliation: Centro para la Investigación y Rehabilitación de las Ataxias Hereditarias (CIRAH), Holguín, Cuba.
authors.forename: L
authors.initials: L
authors.lastname: Velázquez-Pérez
authors.forename: C
authors.initials: C
authors.lastname: Seifried
authors.forename: M
authors.initials: M
authors.lastname: Abele
authors.forename: F
authors.initials: F
authors.lastname: Wirjatijasa
authors.forename: R
authors.initials: R
authors.lastname: Rodríguez-Labrada
authors.forename: N
authors.initials: N
authors.lastname: Santos-Falcón
authors.forename: G
authors.initials: G
authors.lastname: Sánchez-Cruz
authors.forename: L
authors.initials: L
authors.lastname: Almaguer-Mederos
authors.forename: R
authors.initials: R
authors.lastname: Tejeda
authors.forename: N
authors.initials: N
authors.lastname: Canales-Ochoa
authors.forename: M
authors.initials: M
authors.lastname: Fetter
authors.forename: U
authors.initials: U
authors.lastname: Ziemann
authors.forename: T
authors.initials: T
authors.lastname: Klockgether
authors.forename: J
authors.initials: J
authors.lastname: Medrano-Montero
authors.forename: J
authors.initials: J
authors.lastname: Rodríguez-Díaz
authors.forename: J M
authors.initials: JM
authors.lastname: Laffita-Mesa
authors.forename: G
authors.initials: G
authors.lastname: Auburger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000067528:Ataxins; D002531:Cerebellum / Q000503:physiopathology; D018450:Disease Progression; D042241:Early Diagnosis; D005260:Female; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics; D009434:Neural Pathways / Q000503:physiopathology; D015835:Ocular Motility Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D009801:Oculomotor Muscles / Q000294:innervation / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011379:Prognosis; D012438:Saccades / Q000502:physiology*; D020754:Spinocerebellar Ataxias / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D000067528:Ataxins; D009419:Nerve Tissue Proteins