Neuroimaging in Cerebellar Ataxias: A Diagnostic Approach.

Ataxias are a group of neurologic disorders, with heterogeneous clinical and genetic presentation and with a challenging diagnostic approach that navigates through the neuroimage field. Typical clinical features of ataxias include variable degrees of cerebellar ataxia, as a pure clinical picture or associated with other neurologic or extra neurological symptoms (cognitive impairment, epilepsy, other movement disorders, abnormal ocular movements, systemic symptoms). Neuroimaging plays an important role in the characterization of patients with ataxia. Despite the development of genetics and neuroimaging, some cases remain with no diagnosis. This review proposes a didactic investigation approach for ataxias based on three main magnetic resonance imaging features: a) ataxias without cerebellar atrophy; b) ataxias with pure cerebellar atrophy or olivopontocerebellar atrophy; and c) ataxias with specific imaging features. A comprehensive review of peer-reviewed articles on neuroimaging in diseases associated with cerebellar ataxia was conducted through a search in PubMed and SciELO. For each topic, we discuss the possible diagnosis and suggest a guided investigation. The classification of cerebellar ataxias into distinct categories-based on the presence or absence of cerebellar atrophy and specific neuroradiological features-profoundly enhances the diagnostic approach to these complex disorders.