Cerebral abnormalities in Friedreich ataxia: A review

Friedreich ataxia (FRDA) is an inherited degenerative disorder affecting multiple systems of the body and resulting in symptoms which include progressive ataxia, dysarthria, and cardiomyopathy. Central nervous system pathology has been traditionally ascribed to the spinal cord and dentate nucleus of the cerebellum. However, cerebral abnormalities in FRDA are being increasingly documented via multiple neuroimaging techniques. Understanding the nature and implications of cerebral abnormalities in FRDA provides more comprehensive knowledge of nervous system involvement in this disorder and increases the prospects of identifying effective treatment targets. We review the cerebellar and the cerebral involvement with a focus on the emerging in vivo human neuroimaging findings suggesting wide-spread cerebral involvement, including aberrant cerebellar-cerebral connectivity. We synthesise the findings by proposing potential mechanisms that may drive these effects. Finally, we identify future research directions which, we argue, will lead to a better understanding of the extent and potential mechanisms of cerebral aberrations in FRDA.