Jason Carmel, M.D., Ph.D., director of the Motor Recovery Laboratory and Early Brain Injury Recovery Program at Burke Medical Research Institute was published in the Jan. 8 issue of the Journal of Neuroscience for his article titled, "Electrical Stimulation of Motor Cortex in the Uninjured Hemisphere after Chronic Unilateral Injury Promotes Recovery of Skilled Locomotion through Ipsilateral Control."
The article suggests that the uninjured side of the brain, with the help of electrical stimulation, can promote recovery of motor function when the side that normally controls movement is damaged.
Injury to one side of the motor cortex causes impairment in the opposite side of the body because most corticospinal fibers are crossed. However, a small number of same-sided connections exist and have the potential to compensate when crossed connections are damaged. Previous studies in rats showed that targeted electrical brain stimulation soon after injury can strengthen these same-sided connections and improve motor function. In the latest study, researchers found that electrical stimulation was effective even months (equivalent to years in humans) after injury. In rats with chronic unilateral injury, ten days of electrical stimulation to the uninjured motor cortex led to almost complete recovery of motor skills. (To demonstrate that the recovery was indeed due to strengthened same-sided connections from the uninjured motor cortex, the researchers pharmacologically inactivated that part of the brain and showed that the impairment returned.) Ultimately, the researchers hope that electrical brain stimulation to boost spared connections may help patients regain motor function even long after injury.