Features of Creutzfeldt-Jakob disease in brains of patients with familial dementia of Alzheimer type.

Necropsy findings consistent with spongiform encephalopathy of the Creutzfeldt-Jakob type are described in the brain of a 48-year-old woman whose prolonged course and clinical features had suggested Alzheimer's presenile dementia. Six other members of her family in two generations have also died of progressive presenile dementing illnesses of Alzheimer type, lasting 5-10 years. Autopsies showed a post-viral temporal lobe encephalopathy in one and spongiform (C-J) lesions in another. Neuropathological studies in this family add weight to the idea that Alzheimer's disease and Creutzfeldt-Jakob disease represent different manifestations of a genetic predisposition to "slow virus" encephalopathies.