A longitudinal investigation of SCA1, SCA2, SCA3, SCA6, and SCA7 cognition progression showed impairment in Stroop C-W Test and oral SDMT, which reflected a relatively slow psychomotor speed of all the SCA subtypes, but the sample sizes were small in all the subtypes (Moriarty et al., 2016). This evidence concerns the gene CACNA1A and autosomal dominant cerebellar ataxia.