White matter hyperintense lesions in genetically proven spinocerebellar ataxia 8.

We report two brothers with a progressive cerebellar syndrome due to spinocerebellar ataxia type 8 (SCA8). In addition to severe cerebellar atrophy, both had prominent white matter hyperintensities on cranial MRI. This is the first report of white matter hyperintensities on cranial MRI in patients with SCA8. A disorder due to a similar molecular basis, myotonic dystrophy 1 (DM1), is known to have white matter hyperintensities on cranial MRI. Cognitive impairment is well described in DM1 and is being recognized in SCA8. The significance of these associations is discussed.