Neuropathological changes in the nucleus basalis correlate with clinical measures of dementia.

The present study correlates the severity of dementia in Alzheimer's disease with the degree of neuropathology present in the nucleus basalis of Meynert. We assessed neurofibrillary tangles, neuronal loss and morphometric changes in 21 patients with Alzheimer's disease who underwent extensive neuropsychological testing before death. We report a highly significant correlation between scores in the psychological tests and all of the neuropathological markers examined within the nucleus basalis of Meynert. The test that correlated most closely with these morphological measures was Folstein's Mini Mental State. Among the different neuropathological changes, the number of neurofibrillary tangles was strongly correlated with the degree of dementia. We also provide evidence for a differential involvement of the three subdivisions of the nucleus basalis in Alzheimer's disease neuropathology. The posterior subdivision, which provides a substantial cholinergic input to the parahippocampal gyrus, was the more profoundly affected. Taken together, these results point to an important participation of the nucleus basalis in dementia of the Alzheimer type. In addition, the strong correlation between neuropathological changes and neuropsychological scores indicates the reliability of these tests in assessing the progression of the disease.