Tract-specific white matter microstructure and gait in humans

Area of Science:

• Neuroscience
• Human Movement Science
• Neuroimaging

Background:

• Gait is a complex motor function reliant on extensive brain network communication.
• The specific white matter tracts crucial for gait control remain largely unidentified.

Purpose of the Study:

• To investigate the association between the microstructural integrity of 14 major brain white matter tracts and gait performance.
• To identify which white matter tracts are most critical for maintaining healthy gait in community-dwelling older adults.

Main Methods:

• Diffusion tensor imaging (DTI) was used to assess white matter microstructure in 2330 dementia- and stroke-free individuals.
• Gait was objectively measured using an electronic walkway, quantifying Global Gait and 7 specific gait domains.
• Statistical analyses examined correlations between white matter tract integrity and gait parameters.

Main Results:

• Higher white matter microstructure integrity was significantly associated with better Global Gait, Phases, Variability, Pace, and Turning.
• The strongest associations were observed in thalamic radiations, followed by association tracts and the forceps major.
• Improved white matter integrity correlated with larger strides, increased single support time, reduced stride-to-stride variability, and fewer turning steps.

Conclusions:

• Intact white matter microstructure is vital for maintaining optimal gait function in community-dwelling older adults.
• Thalamocortical pathways, association tracts, and interhemispheric connections (e.g., forceps major) are particularly important for gait control.
• These findings highlight the necessity of preserving white matter integrity for mobility and independence in aging populations.