Temporal morphology and neuropsychological correlates in Alzheimer's disease and normal aging.

摘要

The purpose of this study was to investigate temporal lobe morphology in Alzheimer's disease (AD) and the relationship between temporal lobe morphology and neuropsychological performance. Specific temporal structures included the hippocampus (H), parahippocampal gyrus (PG), fusiform gyrus (FG), superior temporal gyrus (STG), middle temporal gyrus (MTG), and inferior temporal gyrus (ITG), along with the temporal horn of the lateral ventricle and the white matter of the temporal stem, an index of white matter integrity. All of these measures were taken from the left temporal lobe. Total brain volume was also included as a variable in the analyses. A neuropsychological test battery was administered which included tests of memory and language ability. The hypothesis was that deficits in language-oriented tests would be correlated with reduced volume in language-mediating left temporal gyri (STG, MTG, and ITG). Deficits in verbal memory would correlate with reduced volumes in the H, PG, and FG. The results indicated significant colinearity among variables. Factor analysis and general linear modeling (GLM) regressions were performed, and two models fit the data and existing theory. A three-factor model resulted in factors for the temporal gyri, the whole brain, and the temporal horn measures, with the hippocampus and central white measures being equally weighted on the temporal gyri and total brain factors. The four factor model was almost identical except that the hippocampus formed its own factor. Factor analysis for the neuropsychological measures resulted in one factor. GLM models of the data indicated that brain structures were not significant predictors of neuropsychological performance, but that demographic variables (age and diagnosis) significantly predicted neuropsychological performance.