Glucose uptake is decreased in affected lower leg muscles of hemiparetic persons during level walking

Stroke patients suffer from gait disturbance due to altered leg muscle actions. Many kinesiological studies have investigated muscle actions, but the metabolic activity of muscles in stroke patients remains to be investigated. We therefore evaluated energy consumption in lower extremity muscles during level walking in hemiparetic individuals. Glucose uptake was measured by positron emission tomography (PET) using ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) in eight hemiparetic (mean age: 56 years) and 11 healthy (mean age: 26 years) participants. Standardized uptake ratio (SUR) was computed in each muscle to express the ¹⁸F-FDG-uptake level. SUR was compared across gluteal, thigh, and lower leg muscles and across individual muscles within each muscle group. For each muscle, SUR was compared among the paretic limb of hemiparetic participants, the non-paretic limb of hemiparetic participants, and the right limb of healthy participants. In paretic limbs, mean SUR did not differ between the three muscle groups, or between individual muscles within each muscle group. SURs of paretic lower leg muscles and gluteus minimus muscle were significantly smaller than those of non-paretic limb and healthy participants (p < 0.05). In the non-paretic limb of hemiparetic participants, SUR of the lower leg muscles was larger than that of the thigh muscles (p < 0.05). Unexpectedly, SURs of medial hamstring and posterior tibial muscles were larger in the non-paretic limb of hemiparetic participants, compared to the right limb of healthy participants (p < 0.05). ¹⁸F-FDG PET is useful to evaluate energy consumption levels of lower extremity muscles during level walking in hemiparetic individuals.