Neural Biomarkers of Functional Recovery in Patients with Injured Motor System

Rehabilitation procedures require an objective evaluation of motor recovery to optimize their functional outcomes. Here, we propose an innovative framework for the identification of neural biomarkers of motor recovery in the forearm muscles of tetraplegic and stroke patients. The system incorporates a custom-made ergometer and high-density surface EMG recordings on the flexor and extensor finger/wrist muscles of the forearm. Blind source separation was used to identify motor unit activity during isometric maximal voluntary contractions. Preliminary results on two patients show a significant increase in the average discharge rate of the identified motor units after some weeks of rehabilitation training. Moreover, the relative change of this parameter matched with the motor recovery exhibited by the patients. This study demonstrates that the identification of individual motor units from the forearm muscles can provide a reliable neural biomarker of motor recovery.