title: Motor decline in clinically presymptomatic spinocerebellar ataxia type 2 gene carriers.
abstract: BACKGROUND
  Motor deficits are a critical component of the clinical characteristics of patients with spinocerebellar ataxia type 2. However, there is no current information on the preclinical manifestation of those motor deficits in presymptomatic gene carriers. To further understand and characterize the onset of the clinical manifestation in this disease, we tested presymptomatic spinocerebellar ataxia type 2 gene carriers, and volunteers, in a task that evaluates their motor performance and their motor learning capabilities.
  
  
  RESULTS
  28 presymptomatic spinocerebellar ataxia type 2 gene carriers and an equal number of control volunteers matched for age and gender participated in the study. Both groups were tested in a prism adaptation task known to be sensible to both motor performance and visuomotor learning deficits. Our results clearly show that although motor learning capabilities are intact, motor performance deficits are present even years before the clinical manifestation of the disease start.
  
  
  CONCLUSIONS
  The results show a clear deficit in motor performance that can be detected years before the clinical onset of the disease. This motor performance deficit appears before any motor learning or clinical manifestations of the disease. These observations identify the performance coefficient as an objective and quantitative physiological biomarker that could be useful to assess the efficiency of different therapeutic agents.
authors.affiliation: Centro para la Investigación y Rehabilitación de las Ataxias Hereditarias, Holguín, Cuba.
authors.forename: Luis
authors.initials: L
authors.lastname: Velázquez-Perez
authors.forename: Rosalinda
authors.initials: R
authors.lastname: Díaz
authors.forename: Ruth
authors.initials: R
authors.lastname: Pérez-González
authors.forename: Nalia
authors.initials: N
authors.lastname: Canales
authors.forename: Roberto
authors.initials: R
authors.lastname: Rodríguez-Labrada
authors.forename: Jacquelín
authors.initials: J
authors.lastname: Medrano
authors.forename: Gilberto
authors.initials: G
authors.lastname: Sánchez
authors.forename: Luis
authors.initials: L
authors.lastname: Almaguer-Mederos
authors.forename: Cira
authors.initials: C
authors.lastname: Torres
authors.forename: Juan
authors.initials: J
authors.lastname: Fernandez-Ruiz
mesh_terms: D000328:Adult; D017668:Age of Onset; D000067528:Ataxins; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats; D009048:Motor Skills / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000235:genetics*; D020754:Spinocerebellar Ataxias / Q000209:etiology / Q000235:genetics* / Q000503:physiopathology*; D013997:Time Factors; D019680:Trinucleotide Repeat Expansion
chemical_list: D000067528:Ataxins; D009419:Nerve Tissue Proteins