Locomotion supraspinal control assessment in healthy people and stroke patients with the use of passive motor fMRI paradigm

Functional magnetic resonance imaging (fMRI) is widely applicable for sensorimotor cortex mapping in human. The most challenging fMRI task for researchers is the assessment of locomotion. The aim of our study was to design of a passive motor fMRI paradigm for assess supraspinal control of the skillof walking in normal subjects and in patients with motor neurologic deficit after ischemic stroke. We conducted fMRI in two groups of human subjects: first group – 19 healthy subjects (10 females and 9 males, mean age = 38 [31,5; 60] years), second group – 18 ischemic stroke patients in early recovery period (first 6 months) (6 females, 12 males, mean age = 55,5 [45,5; 64,5] years) with severe and moderate (mean Fugl- Meyer scale score = 22 [15; 28]).The protocol consisted of blocked-design paradigm: plantar stimulation by imitation of slow walking vs rest. Individual and group activation patterns were analyzed using statistical package SPM5. A significant activation (pcorrect<0.05 at cluster level) in first group was observed in the primary and secondary sensorimotor cortex, premotor and dorsolateral prefrontal cortex, in insula. Due to lesion localization second group was subdivided into corticalsubcotrical (CS) and subcortical (S) subgroups. In CS subgroup there was reduce of activation size, more prominent in the affected hemisphere, whereas in S subgroup the extension of activation regions in both hemispheres was revealed, comparing to group 1. It was demonstrated that our passive motor fMRI paradigm of walking imitation with the use of plantar load imitator Korvit can be used to localize the ensorimotor brain areas involved in locomotion in both healthy people and patients. Concerning stroke patients, such an approach can help in understanding the mechanisms of supraspinal control of the skill walking and optimal rehabilitation strategy.