Brain Connectivity Modulation After Exoskeleton-Assisted Gait in Chronic Hemiplegic Stroke Survivors: A Pilot Study.

Abstract

The aim of this study was to investigate electroencephalographic (EEG) connectivity short-term changes, quantified by node strength and betweenness centrality, induced by a single trial of exoskeleton-assisted gait in chronic stroke survivors. Study design was randomized crossover. Electroencephalographic data (64-channel system) were recorded before gait (baseline) and after unassisted overground walking and overground exoskeleton-assisted walking. Coherence was estimated for alpha1, alpha2, and beta frequency ranges. Graph analysis assessed network model properties: node strength and betweenness centrality. Nine participants were included in the final analysis. In the group (four participants) with a left-hemisphere stroke lesion (dominant hemisphere), over the vertex, node strength increased in alpha1, alpha2, and beta bands, and betweenness centrality decreased in alpha2 both after unassisted overground walking and exoskeleton-assisted walking. In the group (five participants) with a right-hemisphere lesion (nondominant hemisphere), node strength increased in alpha1 and alpha2 over the contralesional sensorimotor area and ipsilesional prefrontal area after overground exoskeleton-assisted walking, compared with baseline and unassisted overground walking. A single session of exoskeleton training provides short-term neuroplastic modulation in chronic stroke. In participants with a nondominant hemisphere lesion, exoskeleton training induces activations similar to those observed in able-bodied participants, suggesting a role of lesion lateralization in networks' reorganization.