MRI predictors of cognition in subcortical ischemic vascular disease and Alzheimer’s disease

Abstract

Results suggest that cognitive impairment associated with subcortical ischemic vascular disease is primarily a result of associated hippocampal and cortical changes.

Cognitive and neuroimaging predictors of instrumental activities of daily living

“…For this reason it may be that neither lacunes nor WMH are particularly important markers of disease in this sample. Analyses of neuroimaging data from the parent study have shown that HV (and cortical gray matter) tend to be more strongly associated with cognition than WMH and volume of lacunes (Mungas et al, 2005;Mungas et al, 2001). It is therefore possible that the contribution of white matter disease in this sample with substantial AD is lesser.…”

Hippocampal volume and retention in Alzheimer's disease

“…Cortical gray matter volume reflects the degree of cortical atrophy, with smaller cortical gray matter volume indicating greater cortical atrophy. In AD, cortical gray matter correlates significantly with overall cognitive functioning and degree of dementia, and thus can be viewed as a marker of dementia severity (Fein et al, 2000;Mungas et al, 2001). When cortical gray matter, hippocampal volumes and white matter signal hyperintensities were simultaneously entered into a regression model predicting immediate recall, only cortical gray matter volume explained a significant proportion of the variance.…”

“…Image acquisition and segmentation methods have been previously described (Fein et al, 2000;Mungas et al, 2001). A computer algorithm was used to classify brain MRI pixels first into principal tissue types of gray matter, white matter, and cerebrospinal fluid.…”

“…Alzheimer's disease (AD) is a particularly important target population to study because pathological signs of the disease are first observed in the medial temporal lobe, and memory impairment is a hallmark feature (Braak & Braak, 1995). Hippocampal atrophy in AD patients has been shown to predict impaired memory performance (Jack et al, 1999;Mungas et al, 2001;Petersen et al, 2000). Furthermore, there is a fair degree of specificity in this relationship in AD patients, with memory scores selectively related to hippocampal volumes, and non-memory performances related to other brain regions (Fama et al, 1997).…”

“…These abilities may be mediated primarily by frontal and other cortical structures rather than the hippocampus (Fletcher & Henson, 2001;Squire, 1992;Stuss & Alexander, 2000). Memory performance can also be influenced by subcortical structures and white matter (Mungas et al, 2001).…”