Juvenile Alzheimer's disease with cerebellar involvement.

We describe a sporadic case of Alzheimer's disease with cerebellar involvement in a man, who died at age 32 years after an illness lasting seven years, which was marked by progressive dementia and ataxia. The brain was quite atrophic and showed numerous senile plaques of all types and neurofibrillary tangles in the cerebral cortex with some involvement of the basal ganglia and diencephalon. There was cerebellocortical atrophy with numerous large, kurulike plaques. In addition, widespread severe congophilic angiopathy was noted.