Gait speed is slower in older individuals with cognitive impairment, when compared to those with normal cognition, suggesting that the pathological brain processes which lead to loss of brain volumes and cause cognitive impairment also affect gait control.

• To examine the patterns of grey brain matter (GM) volume covariance associated with gait speed in cognitively healthy individuals (CHI) and in patients with mild cognitive impairment (MCI).

The design is a cross-sectional study.

A subset of 96 CHI (mean age 69.9±3.7) and 99 patients with MCI (mean age 70.7±4.61) recruited in the “Gait and Alzheimer Interactions Tracking” study was selected. Brain GM volumes measured with voxel-based morphometry and self-paced gait speed served as outcomes.

Brain GM volumes of right middle frontal and precentral gyri were positively associated with gait speed in CHI (i.e. slow gait speed was associated with low GM volumes). Striatum (i.e. left putamen and bilateral caudate nuclei) volumes were positively associated with gait speed in patients with MCI. The right middle frontal gyrus volume covaried with cortical frontal region volume in CHI, whereas the left putamen volume covaried with the left putamen and the right caudate nucleus volumes in patients with MCI. Additionally, in patients with MCI the right caudate nucleus was associated with the different volumes of the right caudate nucleus, right frontal regions and the left superior medial frontal gyrus.

Slow gait speed was associated with low brain volumes, and solicited a network of GM regions in the frontal cortex in CHI and the striatum in MCI.