MRI of the brain. MRI was performed on Patient 1 at 12 years of age. T1W1 sagittal image demonstrates prominent cerebellar atrophy involving superior and middle cerebellar folia. Axial images (not shown) revealed normal subcortical and cerebellar white matter. MR spectroscopy was normal (not shown). Repeat MRI imaging at 16 years old was unchanged (not shown). MRI of the brain (Patient 2) showed a similar pattern but milder cerebellar atrophy (not shown).