Objective:

The objective of the study was to evaluate the characteristics of white matter tracts by diffusion tensor imaging (tractography) in elderly people with dementia type Alzheimer’s disease (AD) and mixed dementia through the measurements of fractional anisotropy (FA) and mean diffusivity (MD).

Methods:

Eight patients with AD and eight patients with mixed dementia were studied. Clinical, cognitive, and neuroimaging evaluation was carried out. Variables are described using the arithmetic mean, standard deviations, and frequencies. Chi-square and U Mann–Whitney tests were used. Correlation analysis was performed between neuropsychological characteristics and the degree of affection by tractography (FA and MD).

Results:

Significant differences were found between the groups of AD versus mixed dementia in FA: right cerebral peduncle 0.5733 versus 0.5557 (p < 0.05), left cerebral peduncle 0.5744 versus 0.5476 (p < 0.01), right external capsule 0.3619 versus 0.3346 (p < 0.01), and left cingulum gyrus 0.4049 versus 0.3756 (p < 0.05). MD: right thalamic posterior radiation 0.0016 versus 0.0010 (p < 0.03) and left external capsule 0.0015 versus 0.0012 (p < 0.03).

Conclusion:

Using tractography, it is possible to quantify the extent of damage to the white matter tracts (vascular and neurodegenerative).

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