Motor decline in clinically presymptomatic spinocerebellar ataxia type 2 gene carriers

• Published in: PloS one Vol. 4; no. 4; p. e5398
• Main Authors: Velázquez-Perez, Luis, Díaz, Rosalinda, Pérez-González, Ruth, Canales, Nalia, Rodríguez-Labrada, Roberto, Medrano, Jacquelín, Sánchez, Gilberto, Almaguer-Mederos, Luis, Torres, Cira, Fernandez-Ruiz, Juan
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 29.04.2009; Public Library of Science (PLoS)
• Subjects: Adult; Age; Age of Onset; Ataxia; Ataxins; Biomarkers; Case-Control Studies; Chemical compounds; Female; Genes; Genetic aspects; Humans; Huntingtons disease; International organizations; Learning; Male; Medical imaging; Middle Aged; Minisatellite Repeats; Motor skill learning; Motor Skills - physiology; Motor task performance; Mutation; Nerve Tissue Proteins - genetics; Neurological Disorders/Movement Disorders; Neurological Disorders/Neurogenetics; Neurological Disorders/Neuromuscular Diseases; NMR; Nuclear magnetic resonance; Pharmacology; Sensorimotor integration; Spinocerebellar ataxia; Spinocerebellar Ataxias - etiology; Spinocerebellar Ataxias - genetics; Spinocerebellar Ataxias - physiopathology; Time Factors; Tomography; Trinucleotide Repeat Expansion
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0005398

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. 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. 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.