A recent study showed that application of rehabilitation training after treatment should be delayed, and that training simultaneously with treatment worsened function. Work from our group as well as from others have shown that brain electrical stimulation can also have delayed benefits on motor recovery.
We plan to study the motor function of an impaired forelimb and its sparse spinal cord innervation, as a model of weak motor control found in people with cervical Spinal Cord Injury (SCI). A transection of the pyramid tract will enable us to identify CST-specific mechanisms of recovery. In addition, our plan to measure supination, a critical component of hand dexterity that is commonly impaired in cervical SCI patients using a novel behavioral task that is objective and automated will make our results highly relevant to clinical practice. Our strategy is to strengthen the spared CST connections that remain in most patients after SCI by promoting greater functional recovery through a combination of motor cortex electrical stimulation and rehabilitation training. The central hypothesis of this project is that stimulation of motor cortex followed by delayed motor training will promote more corticospinal tract (CST) connections and greater recovery of function than application of motor training immediately after stimulation. We expect that our results will be highly relevant to the most prevalent group of SCI patients who live with chronic injuries, since we will study the effects of delayed motor training and should enable the development of more efficacious motor rehabilitation therapies for people with SCI.