Quantitative assessment of the density of neurofibrillary tangles and senile plaques in senile dementia of the Alzheimer type. Comparison of immunocytochemistry with a specific antibody and Bodian's protargol method.

Counts of neurofibrillary tangles and senile plaques were performed in two adjacent sections from the temporal lobe in 14 women aged over 75 years at death. The mental status of these cases had been prospectively assessed by the test score of Blessed, Tomlinson and Roth. They were either intellectually normal or had senile dementia of the Alzheimer type of various degrees of severity. The first section was silver-impregnated according to Bodian's method; the second one was immunolabeled with an antiserum raised against neurofibrillary tangles. Densities of neurofibrillary tangles and senile plaques evaluated by the two techniques were highly correlated but their means of differences and limits of agreement were large. The correlation with the clinical data was similar for the two methods. Both techniques can thus be used with the same accuracy in correlative studies but their results are not interchangeable without caution.