The key goals of SPORTAX-NHS is to compare the phenotype of multiple system atrophy of cerebellar type (MSA-C) and sporadic adult onset ataxia of unknown aetiology (SAOA) and to determine the rate of disease progression in both groups including determination of the factors that predict the development of MSA-C vs. SAOA, and at which time after onset of ataxia, a reliable distinction between both disorders is possible. The planned study will also allow to collect blood samples and other biomaterials from patients with sporadic ataxia, which will be useful for future genetic and biomarker studies.