Gait disturbance associated with white matter changes: a gait analysis and blood flow study.

To clarify the mechanisms underlying gait disturbance secondary to age-related white matter changes (ARWMC), cerebral perfusion was investigated during treadmill walking. Twenty subjects with extensive hyperintensities in the periventricular and deep white matter on T(2)-weighted magnetic resonance images (MRI) were recruited. The ARWMC subjects were classified into gait-disturbed (GD) and non-GD groups according to clinical criteria. All the subjects underwent gait analyses and cerebral perfusion measurements during both gait and rest by using single photon emission computed tomography. The GD group showed greater double support time/phase and stride width, and slower walking velocity, than the non-GD group. In an analysis of pooled data from all the subjects, gait-induced increases in cerebral perfusion were observed in the supplementary motor areas (SMA), lateral premotor cortex (PMC), primary motor and somatosensory areas, visual areas, basal ganglia and cerebellum. A between-group comparison of gait-induced perfusion changes showed relative underactivation of the SMA, thalamus and basal ganglia, together with relative overactivation of the PMC, in the GD group compared with the non-GD group. In a separate correlation analysis including all the subjects, as the double support phase was longer (that was, gait disturbance was more severe), the gait-induced perfusion changes were proportionally reduced in the SMA, visual cortex, and thalamus. The present study suggests that abnormalities in the basal ganglia-thalamo-cortical loops partly explain gait disturbance observed in a subset of subjects with ARWMC.