Science is currently on a winning streak; a groundbreaking new therapy has incredibly allowed four paraplegic men to voluntarily move muscles that were previously paralyzed. The results have been published in the journal Brain.
Back in 2009, a trial began to investigate whether electrical stimulation of the spinal cord, via an implanted 16-electrode array, in combination with treadmill training could offer some hope to paralyzed patients. Rob Summers, who was paralyzed below the chest, participated in the trial. A team of researchers helped him to move his legs whilst he was suspended over a treadmill; at the same time his spinal cord was stimulated by the device. Amazingly, 7 months later, he regained some voluntary control of his legs and also the ability to stand for short periods of time without assistance.
In paralyzed individuals, the neural connections that transmit information between the brain and certain parts of the body are disrupted. What this electrical stimulation does is mimic the brain signals that would usually be shooting down the spinal cord in order to propagate movement of the limbs.
The recently published study, carried out by researchers from the University of Louisville, UCLA, and the Pavlov Institute of Physiology, was a continuation of this initial work, and involved new tests on Summers alongside three other new participants. One of the participants had a similar condition to Summers in that he had complete motor paralysis but incomplete sensory paralysis, i.e. he could still experience some sensation below the injury. The other two men had complete motor and sensory paralysis. None of the participants were able to move their lower limbs before the epidural stimulator was implanted.
The researchers were initially skeptical about the potential success of this novel treatment on the two men with sensory as well as motor paralysis, but the results were a blissful surprise. Incredibly, all of the men regained the voluntary ability to move their hips, ankles and toes, and could even modulate the movement in response to certain auditory and visual cues. What also pleasantly surprised the researchers was how remarkably quickly the men recovered voluntary movement.
The results improved when the stimulation was combined with rehabilitative therapy, which involved home-based movement training during periods of stimulation. Over time less stimulation was required for the initiation of movement, and the voluntary movements became stronger.
The apparent speed of movement recovery of these men suggested that there may have been some non-functional remaining connections between areas above and below the injury. The spinal stimulation may therefore have been able to rejuvenate these dormant connections.
UCLA’s V. Reggie Edgerton, who pioneered this novel approach, said in a press release “The fact that the brain is able to take advantage of the few connections that may be remaining, and then process this complicated visual, auditory, and perceptual information, is pretty amazing.”
Prior to these studies, the outlook for patients with motor paralysis was bleak. Although it’s still early days, the researchers are hopeful that this new technique may provide hope to individuals with previously untreatable conditions.