Findings in FRDA were compared with findings in the most common forms of dominantly inherited ataxias [spinocerebellar ataxia types 1, 2, 3 and 6 (SCA1,2,3,6)] and a common form of non-hereditary degenerative ataxia [multiple system atrophy, cerebellar type (MSA-C)]. QSM revealed different patterns of abnormalities in the dentate nuclei. Abnormalities in susceptibility were most pronounced in SCA1, MSA-C and SCA6 patients. While susceptibility was significantly higher in SCA1 and MSA-C, it was significantly lower in SCA6 compared with healthy controls. Smaller changes in susceptibility were found in the dentate nuclei in FRDA and SCA2 and no change in SCA3 patients. Our data suggest that changes in iron concentration may contribute to the pathogenesis of a subset of cerebellar ataxias or at least be a result or indicator of the underlying pathology.
