Hand Motor Rehabilitation of Patients with Stroke Using Physiologically Congruent Neurofeedback

摘要

Neurorehabilitation of hand motor function in stroke patients is one of the most promising applications of the brain-machine interface (BMI). We developed Digital Mirror Box (DMB), a BMI-based rehabilitation system that can train the affected motor cortical activity of stroke patients with hand paralysis. DMB detects event-related desynchronizations (ERDs) in the mu band (8-13 Hz) activity derived from hand motor imagery and it further provides proprioceptive feedback upon successful generation of ERD. We investigated the effect of both a single use and a two-week repetitive use of DMB on the ERD power and finger muscle spasticity, as well as performed the Fugl-Meyer Assessment (FMA) of the upper extremity in 36 stroke patients with hand paralysis. Participants were subjected to motor imagery coupled with a movie of hand gestures that was presented on a tablet screen to facilitate ERD generation. A pneumatic robotic exoskeleton was attached to the paralyzed hand and provided a feedback by moving the hand in gestures that were synchronized with those shown in the movie. A single use of DMB significantly alleviated the muscle spasticity in both flexion and extension. Two-week of DMB repetitive use on top of conventional physiotherapy and occupational therapy also confirmed the statistically significant decrease in muscle spasticity relative to that obtained during control period in which participants performed the same motor imagery training but during which the exoskeleton provided hand movement regardless of ERD power. Furthermore, a statistically significant improvement of hand and finger functions (assessed using FMA) was seen in DMB, but not in the control period. This was associated with a trend in increased ERD power through DMB training period over control period. These results suggest that neurorehabilitation using DMB can ease spasticity and improve hand function via increasing motor-related cortical activity. The physiologically congruent proprioceptive feedback could thus facilitate the functional recovery of patients by stimulating the persisting sensorimotor loop in the affected hemisphere.