Senile dementia of the neurofibrillary tangle type (SD-NFT): a clinical, neuropathological and molecular genetic study

A subset of senile dementia is characterized by numerous neurofibrillary tangles (NFTs) in the hippocampal region, similar to Alzheimer’s disease (AD), but with absence or scarcity of senile plaques (SPs) throughout the brain [1]. These cases have been reported as an atypical or NFT-predominant form of AD [2]. We studied demented elderly patients with such neuropathological features [3, 4], compared them with age-matched AD patients in clinicopathological and genetic aspects, and investigated whether the senile dementia characterized by NFTs was just a subtype of AD or an independent disease entity [4]. Our results indicated that this neuropathological condition represents a disease entity with a pathogenetic process different from that of AD [4]. Therefore, we have proposed the term, “senile dementia of the NFT type (SD-NFT)”, which is distinguished from late-onset AD, i.e., senile dementia of the Alzheimer type [4]. Thereafter, the identical neuropathological condition has been recently reported under terms such as NFT-dominant form of senile dementia [5], senile dementia with tangles [6], and limbic neurofibrillary tangle dementia [7].