The Relationships Between Ataxia and Cognition in Spinocerebellar Ataxia Type 2

The clinical spectrum of spinocerebellar ataxia type 2 includes motor manifestations and cognitive disturbances in executive functions, memory, and visuoconstructive skills. The relationships between severity of motor disturbances and altered cognition are poorly known. In this study, we assessed patients with spinocerebellar ataxia type 2 and age- and sex-matched healthy control subjects by a test battery including the Mini-mental State Examination, the Wisconsin Card Sorting test, and the Wechsler Memory Scale-Revised. The correlation between severity of motor ataxia (as assessed by a validated and widely used severity scale, the SARA scale, and by an objective automated computerized system of gait analysis) and altered cognition was then evaluated by Spearman correlation analysis. Patients performed worse than healthy controls in almost all administered neuropsychological tests. Nevertheless, only global intellectual abilities and executive functions significantly correlated with the overall severity of ataxia as assessed by the SARA scale, and impaired executive functions alone correlated with performance on several spatio-temporal gait analysis parameters. Our findings would probably suggest a prominent influence of executive functions on motor abilities in patients with spinocerebellar ataxia type 2 and raise the possibility that cognitive pharmaceutical or rehabilitative interventions may be of benefit in the management of motor problems in these patients.