Motor decline in clinically presymptomatic spinocerebellar ataxia type 2 gene carriers.
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.
Velázquez-Perez
Luis
L
Centro para la Investigación y Rehabilitación de las Ataxias Hereditarias, Holguín, Cuba.
Díaz
Rosalinda
R
Pérez-González
Ruth
R
Canales
Nalia
N
Rodríguez-Labrada
Roberto
R
Medrano
Jacquelín
J
Sánchez
Gilberto
G
Almaguer-Mederos
Luis
L
Torres
Cira
C
Fernandez-Ruiz
Juan
J
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
D000067528:Ataxins; D009419:Nerve Tissue Proteins