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Updated: Aug 7, 2025
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Localized White Matter Tract Integrity Measured by Diffusion Tensor Imaging Is Altered in People with Mild Cognitive
Seyyed M H Haddad1, Frederico Pieruccini-Faria2,3, Manuel Montero-Odasso2,3,4
1Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, Canada.
Background:
Altered white matter (WM) tract integrity may contribute to mild cognitive impairment (MCI) and gait abnormalities.
Objective:
The purpose of this study was to determine whether diffusion tensor imaging (DTI) metrics were altered in specific portions of WM tracts in people with MCI and to determine whether gait speed variations were associated with the specific DTI metric changes.
Methods:
DTI was acquired in 44 people with MCI and 40 cognitively normal elderly controls (CNCs). Fractional anisotropy (FA) and radial diffusivity (RD) were measured along 18 major brain WM tracts using probabilistic tractography. The average FA and RD along the tracts were compared between the groups using MANCOVA and post-hoc tests. The tracts with FA or RD differences between the groups were examined using an along-tract exploratory analysis to identify locations that differed between the groups. Associations between FA and RD in whole tracts and in the segments of the tracts that differed between the groups and usual/dual-task gait velocities and gross cognition were examined.
Results:
Lower FA and higher RD was observed in right cingulum-cingulate gyrus endings (rh.ccg) of the MCI group compared to the CNC group. These changes were localized to the posterior portions of the rh.ccg and correlated with gait velocities.
Conclusion:
Lower FA and higher RD in the posterior portion of the rh.ccg adjacent to the posterior cingulate suggests decreased microstructural integrity in the MCI group. The correlation of these metrics with gait velocities suggests an important role for this tract in maintaining normal cognitive-motor function.
Insights
Mild cognitive impairment (MCI) is linked to reduced white matter integrity in the right cingulum-hippocampal pathway, affecting gait speed. These findings highlight the role of this tract in cognitive-motor function.
Area of Science:
- Neuroimaging
- Neuroscience
- Gerontology
Background:
- Altered white matter (WM) tract integrity is implicated in mild cognitive impairment (MCI) and gait disturbances.
- Investigating specific WM tract changes in MCI is crucial for understanding cognitive and motor decline.
Purpose of the Study:
- To assess diffusion tensor imaging (DTI) metric alterations in specific WM tracts in individuals with MCI.
- To determine the association between DTI metric changes and variations in gait speed within the MCI group.
Main Methods:
- Diffusion tensor imaging (DTI) data were collected from 44 MCI patients and 40 cognitively normal controls (CNCs).
- Fractional anisotropy (FA) and radial diffusivity (RD) were measured in 18 major WM tracts using probabilistic tractography.
- Group comparisons and along-tract analyses identified specific regions with differing microstructural integrity, correlating these with gait velocity and cognition.
Main Results:
- The MCI group exhibited lower FA and higher RD in the right cingulum-cingulate gyrus (rh.ccg) endings compared to CNCs.
- These microstructural differences were localized to the posterior segments of the rh.ccg.
- Reduced FA and increased RD in the posterior rh.ccg correlated significantly with slower gait velocities.
Conclusions:
- Decreased microstructural integrity in the posterior right cingulum-hippocampal tract (rh.ccg) is evident in individuals with MCI.
- The observed correlation between altered rh.ccg integrity and gait velocity underscores its critical role in maintaining cognitive-motor function.
