Evidence of Neuroplasticity With Robotic Hand Exoskeleton Study for Post-Stroke Rehabilitation: A Randomized Controlled Trial

Abstract

Background: A novel electromechanical robotic-exoskeleton was designed in-house for rehabilitation of wrist joint and Metacarpophalangeal (MCP) joint. Objective: The objective was to compare the rehabilitation effectiveness (clinical-scales and neurophysiological-measures) of robotic-therapy training-sessions with dose-matched control in patients with stroke. Methods: A pilot prospective parallel single-blinded randomized controlled study at clinical-settings was designed with patients with stroke within 2 years of chronicity. Patients were randomly assigned to receive an intervention of 20 sessions of 45-minutes each, five days a week for four-weeks, in Robotic-therapy Group (RG) (n=12) and conventional upper-limb rehabilitation in Control-Group (CG) (n=11). We hypothesized to evaluate the exoskeleton based therapy for the effects on functionality of upper-limb and cortical-excitability in patients with stroke as compared to conventional-rehabilitation. Clinical-scales– Modified Ashworth Scale, Active Range of Motion, Barthel-Index, Brunstrom-stage and Fugl-Meyer scale (Shoulder/Elbow and Wrist/Hand component), and neurophysiological-measures of cortical-excitability (using Transcranial Magnetic Stimulation) –Motor Evoked Potential and Resting Motor-threshold, were acquired pre and post-therapy. No side effects were noticed in any of the patients. Results: RG and CG showed significant (p<0.05) improvement in all clinical motor-outcomes except Modified Ashworth Scale in CG. RG showed significantly (p<0.05) higher improvement over CG in Modified Ashworth Scale, Active Range of Motion and Fugl-Meyer (FM) scale and FM Wrist-/Hand component). Increase in cortical-excitability in ipsilesional-hemisphere was found to be statistically significant (p<0.05) in RG over CG, as indexed by decrease in Resting Motor-Threshold and increase in amplitude of Motor Evoked Potential. No significant changes were shown by the contralesional-hemisphere. Interhemispheric RMT-asymmetry evidenced significant (p<0.05) changes in RG over CG indicating increased cortical-excitability in ipsilesional-hemisphere along with interhemispheric changes. Conclusion: Neurophysiological-changes in RG could most likely be a consequence of plastic-reorganization and use-dependent plasticity. Robotic-exoskeleton training could significantly improve motor-outcomes and cortical-excitability in patients with stroke.