EFFECT OF WALKING VS SHAM TREATMENT ON FINGER MOVEMENT CONTROL and BRAIN REORGANIZATION IN WELL ELDERLY.

Abstract

Purpose/Hypothesis: Previous studies have shown that aerobic training, including walking, can have beneficial cognitive effects. The possibility that such cognitive effects might improve motor control is real. The purpose of this study was to investigate whether a walking training program could induce improvement in finger tracking performance accompanied by changes in cortical activation within primary motor area (M1), as measured by fMRI, in well elderly subjects. We hypothesized that subjects in the walking group would show greater improvement in finger tracking and significant changes in brain reorganization compared to a sham group. Number of Subjects: Fourteen well elderly subjects were assigned to either a walking group (N = 6, mean age = 81.7, SD = 1.9 years) or a sham group (N=8, mean age 79.8, SD = 2.3 years). Materials/Methods: All subjects wore a pedometer for one week prior to group assignment to record baseline level of walking distance. Subjects assigned to walking group were instructed to double their weekly walking distance within six weeks and then maintain or further increase that distance for an additional six weeks. Subjects assigned to the sham group received one 30-minute treatment per week for 12 weeks of sham electrical stimulation to the finger and wrist extensor muscles of their dominant hand. During this time, they were instructed to maintain their regular walking distance. Before and after training, subjects performed a six-minute finger movement tracking test with functional magnetic resonance imaging of the brain inside a three-Tesla magnet to measure finger movement control and the associated cortical activation. Analysis of data was done with paired tests comparing pretest to posttest change for both groups. Results: Results showed that the walking group significantly increased their walking distance (p = 0.003), whereas the sham group showed no change. The finger tracking accuracy increased significantly for the walking group (p = 0.01), whereas for the sham group no change occurred. Despite the significant improvement in tracking performance in the walking group, there were no significant changes in measurements of brain reorganization (active voxel count and signal intensity) in M1 of either group. Conclusions: We concluded that walking training improved finger movement tracking control in well elderly subjects but did not show a change in brain reorganization. The absence of significant change in brain reorganization accompanying the behavioral improvement may be due to the area (M1) studied or the time at which the cortical activity was measured at posttest. Clinical Relevance: These results suggest that an active walking training program has beneficial effects on fine motor control of movements unrelated to the walking exercise. The possibility exists that aerobic/walking training, through molecular mechanisms not yet identified, may have similar beneficial effects on motor control in patients with neurological problems.