Key points are not available for this paper at this time.
A morphometric technique employing Congo red staining and scanning light microscopy with appropriate filters provided a sensitive sampling method for counting hippocampal neurons bearing neurofibrillary tangles in serially sectioned temporal lobes from mentally normal subjects of different ages as well as from demented patients. The number of tangled neurons per mm 3 of cortex was compared with patients' ages. Tangle formation in controls increased only slightly with age; whereas the ‘Tangle Index’ of cases with the organic dementia of Alzheimer's disease exceeded by many times that of age‐matched controls. The posterior portion of the hippocampus was found to be more susceptible to this augmented neurofibrillary degeneration than the anterior part of the hippocampus of demented subjects.
Melvyn J. Ball (Wed,) studied this question.