Integrated Functional Evaluation of the Cerebellum

Common inclusion criteria for all participants: * Ability to walk independently 30 foot without an assistive device * Able to stand unassisted for 30 seconds * Affiliated with the French social security, or a social security equivalent, if they are not French. * Capacity to consent * Signed Informed Consent by the subject * Ability to undergo MRI scanning Inclusion criteria for SCA patients: * Genetic diagnosis of SCA 2 or 7 (available CAG repeat length) * SARA score ≤15 Inclusion criteria for control participants: * Negative Genetic diagnosis of SCA2/SCA7 available * No significant neurological symptoms * SARA score \< 5 Common inclusion criteria for elective participant for CSF sampling: • Ability to undergo a lumbar puncture Exclusion criteria * Subjects currently receiving, or having received within 2 months prior to enrolment into this study, any investigational drug * Pregnancy or breastfeeding * Genotype consistent with other inherited ataxias * Changes in coordinative physical and occupational therapy for ataxia 2 months prior to study participation * Concomitant disorder(s) or condition(s) that affects assessment of ataxia or severity of ataxia during this study * Contra-indications to MRI examination * Person deprived of their liberty by judicial or administrative decision