MRI atrophy of the caudate nucleus and slower walking speed in the elderly

Cerebral white matter lesions are associated with poorer motor performances in the elderly, but the role of gray matter atrophy remains largely unknown. We investigated the cross-sectional relation between brain regional gray matter volumes and walking speed over 6m in the 3C-Dijon study, a large population-based study of community-dwelling persons aged 65 years and over (N=1623). Regional gray matter volumes were obtained using an automated anatomical labeling parcellation method. Multivariable analyses were performed using a semi-Bayes approach. After adjustment for potential confounders, persons who walked slower had a smaller volume of basal ganglia (regression coefficient [β]=0.054, standard error [SE]=0.028, p=0.05). In more detailed analyses, the volume of the caudate nucleus had a preponderant role on this association (β=0.049, SE=0.019, p=0.009), and walking speed decreased progressively with the volume of the caudate nucleus (p for linear trend<0.001). These results underline the role of gray matter subcortical structures, in particular of the caudate nucleus, in the age-related decline of motor performances among community-dwelling elderly subjects.