Microstructural White Matter Abnormalities Independent of White Matter Lesion Burden in Amnestic Mild Cognitive Impairment and Early Alzheimer Disease Among Han Chinese Elderly

Abstract

This study was designed to evaluate the microstructural integrity of white matter (WM) in amnestic mild cognitive impairment (MCI) and Alzheimer's disease (AD) among Han Chinese elderly using diffusion tensor imaging (DTI) technique, and to investigate the relationship between WM abnormalities and cognitive dysfunction. Sixty-four subjects (23 mild probable AD, 20 amnestic MCI, and 21 age-matched normal controls) who did not have visible WM lesion burden were analyzed. Fractional anisotropy (FA) and mean diffusivity were measured in normal-appearing WM (NAWM) using DTI with 64 encoding directions. The results were correlated with the scores of Mini-Mental State Examination (MMSE) and Cognitive Ability Screening Instrument (CASI). Statistical analysis showed the FA value in parietal WM was significantly lower in MCI compared to NC (P<0.001), and further decreased in AD compared to MCI (P=0.005). The lower FA and elevated mean diffusivity values were found in temporal WM, frontal WM, parahippocampal and posterior cingulate fibers of AD group compared to MCI and NC (all P<0.01). Canonical correlation analysis showed that the parietal FA values measured from all subjects were significantly correlated with the scores of CASI and MMSE (P<0.01). The results indicated that DTI can detect microstructural WM abnormalities in AD and amnestic MCI, and the measures were correlated with cognitive performance. In MCI, the abnormality was found to be limited within the parietal WM; and in AD a more widespread alteration was found in other brain regions as well.

Associations between T1 white matter lesion volume and regional white matter microstructure in aging

“…These findings suggest that some of the NAWM changes may not be directly related to WMSAs, or may occur independently. It may be that at least some of the observed age-related microstructural changes arise via different mechanisms than those that underlie WMSAs, and may not always precede the development of an overt lesion (Liao, et al In Press). The fact that WMSA volume-independent associations between age and FA also occurred in regions peripheral to areas with high frequencies of hypointensities also supports this idea, as it suggests that some changes to NAWM are process-independent of those that eventually develop into overt lesions.…”

Frequency of the Apolipoprotein E ε4 Allele in a Memory Clinic Cohort in Beijing: A Naturalistic Descriptive Study

“…All individuals who participated in the case registry were diagnosed with thorough clinical work-ups that included a documentation of their medical and family history, physical and neurological examinations, neuropsychological assessment, multi-modal neuroimaging check-ups (details as previously described [26]), laboratory investigations (including complete blood count, electrolytes, blood chemistry, thyroid function testing, vitamin B 12 and folic acid levels, syphilis detection values), electrocardiography (ECG), and an optional blood donation for genetic sub-studies. Each subject may have also opted to consent to participate in the longitudinal observational sub-study.…”

Improvement of working memory after stenting for cervicocerebral artery stenosis

“…One patient did not receive the same test form before and after operation. The CMS booklet, first printed in 1984,9published in Acta Psychologica Sinica in 1986,10 and revised and reprinted in 1996,11 has been widely accepted in China and was used by other Chinese authors in their research articles published in English 12 13. The CMS consists of five subtests: directed memory, which measures short term memory; paired association learning, which measures short time verbal learning and memory, and gauges the ability to form and recall verbal associations; free recall of pictures, which measures memory of pictorial information; recognition of meaningless figures, which evaluates visual memory; and associative recall, which measures acquisition of information that has been provided without instructions to memory.…”