NEW YORK (Reuters Health) – Progressive task-repetitive treadmill exercise recruits cerebellum-midbrain and subcortical circuits to promote gait recovery after hemiparetic stroke, according to trial results published in the December issue of Stroke.

Ischemic stroke interferes with the highly integrated sensory-motor control systems required for normal ambulation, Dr. Andreas Luft and colleagues explain. They theorized that “progressive treadmill exercise would improve gait function in subjects with chronic hemiparetic stroke by inducing adaptations in the brain (plasticity).”

The 6-month trial included 71 subjects, age 46 years and older, with chronic hemiparetic gait after a first clinical ischemic stroke and completion of conventional subacute rehabilitation. For most subjects, years had elapsed since their stroke. They were randomized to treadmill exercise (n = 37) or to a control stretching program (n = 34).

Duration and intensity of treadmill exercise started low, at 10-20 minutes and 40-50% of heart rate reserve, increased every 2 weeks as tolerated to a goal of three 40-minute exercise sessions per week at 60% of heart rate reserve.

Treadmill exercise improved treadmill walking velocity by 51% and cardiovascular fitness as measured by peak effort VO2 by 18%; corresponding changes in the control group were 11% and -3%, respectively (p < 0.001 for both).

Overground walking velocity increased by 19% in the treadmill group compared with 8% in the control group.

Neural control of the legs was assessed by functional brain MRI performed during knee motion for 15 subjects in the treadmill exercise group and 17 in the control group.

The fMRI results indicated that “repetitive gait training on a treadmill