O-08 Brain connectivity modulation after exoskeleton gait in chronic stroke survivors: a pilot study

Abstract

Background Restoration of independent gait after stroke is a principal goal of survivors. Exoskeleton overground gait training provides trunk support and inter-limb coordination based on fine-tuning of the robot control parameters. The aim of our study was to identify short-term plasticity based on electroencephalography (EEG) data induced by a single trial of exoskeleton gait training in unilateral hemiplegic stroke survivors. Material and methods 64-channel EEG was recorded before gait (T0), after overground walking (T1) and after overground exoskeleton (EksoGT) gait training (T2) in 9 stroke survivors. Relative power and coherence were estimated for alpha1 (8–10 Hz), alpha2 (10.5–12.5 Hz) and beta (13–30 Hz) frequency ranges. Graph analysis assessed network model properties: node strength (S) and betweenness centrality (BC). Results Left-hemisphere stroke subjects showed S decrease over anterior and posterior cortex in alpha1, alpha2 and beta at T1 and T2. BC decreased at vertex at T1 and T2 in alpha2 and beta. Right-hemisphere stroke subjects displayed power decrease after exoskeleton walking in alpha2 over CPZ and CP2, and in beta over left contralateral sensorimotor cortex (cSM) and right ipsilateral prefrontal cortex (iPFC). S increased in alpha1 and alpha2 over cSM and iPFC at T2; BC decreased in alpha2 over iPFC at T2 compared to T1. Conclusions A single session of tailored exoskeleton training provides short-term neuroplastic modulation in chronic stroke. Right-hemisphere stroke subjects re-establish a more physiological activation network; a similar reorganization does not take place in left-hemisphere stroke subjects, supporting the role of lateralization in limb control and stroke recovery.