Clinical efficacy and cortical network modulation of a multimodal sensory feedback upper-limb rehabilitation robot for post-stroke upper-limb recovery: a randomized controlled trial

Abstract

Background Recovery of upper-limb motor function after stroke often requires intensive, repetitive, task-oriented rehabilitation. Multimodal sensory-feedback robot-assisted training has the potential to enhance patient engagement and sensorimotor integration, and thereby improve rehabilitation outcomes. Aim To investigate the clinical and neurophysiological effects of adding multimodal sensory-feedback robot-assisted training to conventional rehabilitation for post-stroke upper-limb recovery using functional near-infrared spectroscopy (fNIRS). Methods A total of 38 stroke patients were randomly assigned to a control group (conventional rehabilitation, n = 19) or an experimental group (dose-matched conventional rehabilitation plus multimodal sensory-feedback robot-assisted training, n = 19). Upper-limb motor function was assessed before and after intervention using the Fugl-Meyer Assessment for the Upper Extremity (FMA-UE). fNIRS was used to evaluate resting-state functional connectivity (Fisher z-transformed connectivity, zFC) and task-evoked cortical activation (HbO) during shoulder, elbow, and finger flexion tasks. Results No significant between-group difference in FMA-UE was observed at baseline (p > 0.05). After intervention, the experimental group showed significant improvement in FMA-UE, whereas the control group showed a smaller, non-significant improvement; the magnitude of pre–post change differed significantly between groups (p < 0.05). Resting-state fNIRS showed no significant between-group differences in zFC at baseline, whereas post-intervention analyses showed enhanced fronto-motor zFC in the experimental group, including connections involving PreM&SMC, DLPFC, and FEF. Task-fNIRS revealed channel-specific group × time interaction effects in HbO responses during the three motor tasks; post-hoc analyses showed significant post-intervention reductions in cortical activation at selected channels in the control group, whereas the experimental group showed a relatively preserved activation pattern. Conclusion Adding multimodal sensory-feedback robot-assisted training to dose-matched conventional rehabilitation may improve short-term post-stroke upper-limb motor recovery. fNIRS further revealed intervention-related changes in cortical activation and resting-state functional connectivity. Clinical trial registration Identifier, ChiCTR2400080101.