Lower myelin content is associated with poorer gait variability in older adults with cerebral small vessel disease and mild cognitive impairment

Abstract

AbstractBackgroundMobility decline is often observed in individuals with cerebral small vessel disease (cSVD). Loss of myelin in the cerebral white matter is a common feature of cSVD and could be one of the mechanisms contributing to poor mobility; however, this hypothesis remains to be tested. Using myelin water fraction (MWF), we investigated whether myelin content is associated with gait parameters in older adults with cSVD.MethodCross‐sectional data from individuals with cSVD and mild cognitive impairment were analyzed. Myelin content was assessed via MRI multi‐echo gradient and spin echo T2 relaxation sequence, indexed as myelin water fraction (MWF). Gait parameters were measured using an electronic walkway. Hierarchical regression models adjusting for total intracranial volume, age, sex, body mass index, and Mini‐Mental State Examination were conducted to determine the associations between MWF and gait parameters. Significant models were further adjusted for white matter hyperintensity burden.ResultSixty‐four participants were included (mean [SD], age = 75.2y [5.4], 62.5% female). In adjusted models, lower MWF in the cingulum (Unstandardized B (95% CI): ‐5.12 [‐9.21 to ‐1.04], R2change = 0.09, Fchange = 6.31, pchange = 0.015), superior longitudinal fasciculus (‐3.79 [‐7.29 to ‐0.29], R2change = 0.07, Fchange = 4.70, pchange = 0.034), posterior corona radiata (‐4.86 [‐9.45 to ‐0.27], R2change = 0.07, Fchange = 4.49, pchange = 0.039), and body of the corpus callosum (‐4.19 [‐8.19 to ‐0.20], R2change = 0.06, Fchange = 4.41, pchange = 0.040) was associated with higher cycle time variability. White matter hyperintensity burden weakened these associations.ConclusionIn older adults with cSVD, Lower myelin content in specific white matter tracts may contribute to higher gait variability, increasing the overall risk of mobility impairment.