[Primary age-related tauopathy (PART): a novel term to describe age-related tangle pathology encompassing a wide range from cognitively normal condition to senile dementia of the neurofibrillary tangle type].

It has been reported that neurofibrillary tangles (NFTs) are commonly observed in older people, and that some of older individuals with dementia have a large amount of NFTs in the medial temporal lobe without amyloid(Aβ) plaques, which have been referred to as senile dementia of the NFT type (SD-NFT), tangle-predominant senile dementia (TPSD), or tangle-only dementia. In 2014, our international collaborative group proposed a new term, "primary age-related tauopathy(PART)", to describe such age-related tangle pathology, clinically encompassing a wide range from normal to cognitive impairment/ dementia (SD-NFT). This nomenclature would provide a conceptual foundation for future studies leading to development of clinical diagnosis for this condition.