Three main individual grey matter regions were positively correlated with walking speed (i.e.; slower walking speed was associated with lower brain volumes): Right thalamus, right caudate nucleus and left middle frontal gyrus; for normal walking, rapid walking, and dual-task walking conditions, respectively. The structural covariance analysis revealed that prefrontal regions were part of the networks associated with all walking conditions; the right caudate was associated specifically with the hippocampus, amygdala and insula for the rapid walking condition and the left middle frontal gyrus with a network involving the cuneus for the dual-task condition.
These results suggest that brain networks associated with gait control vary according to walking speed and depend on different walking conditions. Gait control in aging involves a broad network of cerebral regions, including regions for emotional control, which are solicited in challenging walking conditions.