Juvenile Alzheimer's disease with myoclonus: amyloid plaques and grumose alteration in the cerebellum.

A case of juvenile Alzheimer's disease is reported with onset at 34 years of age, a clinical course of 6 years, had myoclonic jerks, generalized convulsions, dysarthria and ataxic symptoms. The neuropathological examination indicated kuru-plaques, amyloid angiopathy and grumose alteration (degeneration) in the dentate nucleus. In this case, the plaques in Alzheimer disease is quite rare. This case also demonstrates the complex interrelationship between Alzheimer's disease and various multisystemic degeneration mainly involving the dentate nucleus.