Functional and Structural Imaging and Motor Control in Spinocerebellar Ataxia

Inclusion Criteria: * DNA diagnosis of SCA1, SCA3, or SCA6 * phenotype consistent with the DNA diagnosis * ability to walk 7 meters * the age of 21-85 years * capable of providing informed consent and complying with the trial procedures Exclusion Criteria: * Known recessive, X-linked or mitochondrial ataxias or any other type of ataxia * Concomitant disorder(s) that affect ataxia measures used in this study * Cognitive status on the Montreal Cognitive Assessment \< 24 * Patients who have any type of implanted electrical device (such as a cardiac pacemaker or a neurostimulator), or a certain type of metallic clip in their body (i.e., an aneurysm clip in the brain), and are not eligible for participation in the MRI portion of the study * Individuals who are claustrophobic * Women who are or might be pregnant and nursing mothers * Individuals with psychiatric disorders or dementia, along with other neurological and orthopedic problems that impair hand movements and walking