title: Prism adaptation in spinocerebellar ataxia type 2.
abstract: Patients with spinocerebellar ataxia type 2 (SCA2), develop severe pontine nuclei, inferior olives, and Purkinje cell degeneration. This form of autosomal dominant cerebellar ataxia is accompanied by progressive ataxia and dysarthria. Although the motor dysfunction is well characterized in these patients, nothing is known about their motor learning capabilities. Here we tested 43 SCA2 patients and their matched controls in prism adaptation, a kind of visuomotor learning task. Our results show that their pattern of brain damage does not entirely disrupt motor learning. Rather, patients had impaired adaptation decrement, but surprisingly a normal aftereffect. Moreover, the mutation degree could discriminate the degree of adaptation. This pattern could reflect the net contribution of two adaptive mechanisms: strategic control and spatial realignment. Accordingly, SCA2 patients show an impaired strategic control that affects the adaptation rate, but a normal spatial realignment measured through the aftereffect. Our results suggest that the neural areas subserving spatial realignment are spared in this form of spinocerebellar ataxia.
authors.affiliation: Laboratorio de Neuropsicología, Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico. jfr@servidor.unam.mx
authors.forename: Juan
authors.initials: J
authors.lastname: Fernandez-Ruiz
authors.forename: Luis
authors.initials: L
authors.lastname: Velásquez-Perez
authors.forename: Rosalinda
authors.initials: R
authors.lastname: Díaz
authors.forename: René
authors.initials: R
authors.lastname: Drucker-Colín
authors.forename: Ruth
authors.initials: R
authors.lastname: Pérez-González
authors.forename: Nalia
authors.initials: N
authors.lastname: Canales
authors.forename: Gilberto
authors.initials: G
authors.lastname: Sánchez-Cruz
authors.forename: Edilberto
authors.initials: E
authors.lastname: Martínez-Góngora
authors.forename: Yaquelín
authors.initials: Y
authors.lastname: Medrano
authors.forename: Luis
authors.initials: L
authors.lastname: Almaguer-Mederos
authors.forename: Carola
authors.initials: C
authors.lastname: Seifried
authors.forename: Georg
authors.initials: G
authors.lastname: Auburger
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D004584:Electronystagmography; D005260:Female; D005366:Figural Aftereffect / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D012438:Saccades / Q000502:physiology; D020754:Spinocerebellar Ataxias / Q000145:classification / Q000503:physiopathology*