A quantitative study of neurofibrillary tangles, senile plaques and astrocytes in the hippocampal subdivisions and entorhinal cortex in Alzheimer's disease, normal controls and non-Alzheimer neuropsychiatric diseases

The present quantitative study was performed in order to discriminate patho logical substrates for dementia from Alzheimer changes in normal controls ( NC) and non-Alzheimer neuropsychiatric diseases (NAND). Regional densities of senile plaques (SP), neurofibrillary tangles (NFT) and astrocytes in the cornu ammonis (CA), subiculum and entorhinal cortex were measured and diff erences in these densities among Alzheimer's disease (AD), NAND and NC were statistically compared. Densities of NFT in the CA and subiculum were sign ificantly higher in AD than in NAND, and densities of SP in all regions wer e significantly higher in AD than in NAND. Similarly, NFT density in the su biculum and SP density in all regions were higher in AD than in NC. Regiona l densities of astrocytes in most regions were closely correlated with thos e of Alzheimer changes. In conclusion, the attribution of the Alzheimer cha nges, particularly of NFT, to dementia is neglected when they are confined to the entorhinal cortex. However, the attribution of the Alzheimer changes to dementia should be appreciated when they spread from the entorhinal cor tex to the subiculum and/or CA.