Mamillary bodies in Alzheimer's disease.

The number of senile (neuritic) plaques (SP) and neurofibrillary tangles (NFT) in mamillary bodies (MB) and in the dorsomedial nucleus of the thalamus (DMNT) were assessed in 25 cases of definite Alzheimer's disease. In 20 cases with AD without other CNS disease the MB and DMNT showed SP and/or NFT in 19 (95%). No correlation was found between the number of SP and NFT and the duration or age of onset of the disease. In patients with AD plus another CNS disease, there were fewer SP and NFT regardless of duration and age at onset of the disease. AD is a diffuse disorder with cortical and subcortical changes. The involvement of MB and DMNT suggests that subcortical structures are also implicated in the memory disorder of AD. The association of AD with other diseases that can themselves cause dementia requires further studies, especially regarding the pattern of topographic distribution of the degenerative changes.