Cognitive deficits in spinocerebellar ataxia 2

This is one of the first studies assessing the pattern of cognitive impairm ent in spinocerebellar ataxia 2 (SCA2). Cognitive function was studied in 1 7 patients with genetically confirmed SCA2 and 15 age- and IQ-matched contr ols using a neuropsychological test battery comprising tests for IQ, attent ion, verbal and visuospatial memory, as well as executive functions. Twenty -five percent of the SCA2 subjects showed evidence of dementia. Even in non -demented SCA2 subjects, there was evidence of verbal memory and executive dysfunction. Tests of visuospatial memory and attention were not significan tly impaired in the non-demented group compared with controls. There was no relationship between test performance and motor disability, repeat length or age of onset, while disease duration was shown to be inversely correlate d with two tests reflecting the progression of cognitive deficits during th e course of the disease. Intellectual impairment should therefore not be in terpreted as a secondary effect of progressive motor disability, but repres ents an important and independent part of the SCA2 phenotype.