Senile dementia of the neurofibrillary tangle type: A comparison with Alzheimer's disease

A subset of senile dementia, 'senile dementia (SD) of the neurofibrillary t angle (NFT) type' (SD-NFT), is characterized by numerous NFTs in the hippoc ampal region and absence or scarcity of senile plaques throughout the brain , To elucidate the pathogenesis of SD-NFT in comparison with Alzheimer's di sease (AD), we investigated the hippocampal lesions and analyzed the tau ge ne. The hippocampal regions from 5 patients with SD-NFT were neuropathologi cally evaluated in comparison with AD and nondemented control subjects. The tau gene was analyzed in 3 patients with SD-NFT. The densities of NFTs in the CA1/subiculum and entorhinal cortex of SD-NFT were significantly higher than those in AD. However, hippocampal atrophy, neuronal and synaptic loss , and astrocytic and microglial proliferation in SD-NFT were significantly mild compared with AD. There was no significant difference between SD-NFT a nd AD in the immunoreactivities of NFTs with different anti-tau antibodies. No mutation was found in the tau gene from the SD-NFT patients. Our result s indicate that the neurodegenerative process with NFT formation of the hip pocampal region in SD-NFT would be different from that in AD. Copyright (C) 2001 S. Karger AG, Basel.