We report a case of genetically confirmed spinocerebellar ataxia type 1(SCA1) in which magnetic resonance imaging (MRI) demonstrated a high signal intensity on T2-weightedimages in the white matter of the frontal lobes. The patient was a 60-year-old Japanese man who complainedof gait instability and speech difficulties. He was diagnosed as having spinocerebellar ataxia at theage of 46. A CAG repeat number of the patient was 48/26. Brain MRI showed marked atrophy of the cerebellumand brain stem. The high-signal intensity lesions on T2-weighted MRI in the white matter of the frontallobes were evident in the periventricular regions. Such MRI abnormalities have not been described inSCA1 previously.

Keywords: SCA1, MRI, trinucleotide expansion, CAG repeat, autosomal dominant