The implant, which electrically stimulates the spine, allows two patients to open a lock and more.
Sitting in an examination room surrounded by doctors and scientists, Heather Randulic opened her left arm for the first time since a series of strokes nine years ago, when she was in her early 20s.
“It was an incredible feeling to be able to do it again,” says Rendulich. “I never thought it was possible.”
But immediately after a surgically implanted device sent electrical impulses into her spinal cord Rendulik was able to not only open her hand, but also showed other marked improvements in her hand’s mobility, researchers reported Feb. 20 in Nature Medicine . “We all started crying,” Marco Capogroso, a neuroscientist at the University of Pittsburgh, said at a Feb. 15 press conference. “We didn’t expect it could work so quickly.”
The approach is similar to that recently used for patients paralyzed by spinal cord injuries. The team says this represents a promising new technique for restoring voluntary movement in those left with upper-body paralysis after a stroke.
A stroke occurs when the blood supply to parts of the brain is cut off, often causing short-term or long-term problems with movement, speech and vision. Stroke is a major and often underestimated cause of paralysis; in the United States alone, 5 million people live with some form of motor disability as a result of stroke. Although physical therapy can provide some improvement, there is no treatment that can help these patients regain full control of their limbs—and their lives.
Strokes cause paralysis because the connection between the brain and spinal cord is damaged; the brain tries to tell the spinal cord to move certain muscles, but the message is garbled.
So, using already existing methods of spinal anesthetic injections, the team invented an electrical device that can be placed along the spinal cord to stimulate the nerves there. The stimulation “doesn’t hurt,” says Rendulik. “It feels like a vibration.”
By aligning electrodes on the device with sensory nerves, “we can increase the activation of muscles weakened by stroke,” Douglas Weber, an engineer and neuroscientist at Carnegie Mellon University in Pittsburgh, told a press conference. Impulses from these electrodes seek to amplify signals from the brain so that sensory nerves respond by activating muscles, restoring voluntary control over the body to patients.
Rendulik and another patient in the study showed improvement in motor tasks including drawing a spiral, opening a lock, and grasping and lifting a can of soup when the device was on. Treatment sessions of continuous electrical stimulation were carried out for four hours a day, five days a week for 29 days, and the improvements were maintained for four weeks after treatment was stopped. This leads researchers to optimize that they can get even stronger results if the treatment is combined with intense physical training, Elvira Pirondini, a neuroscientist at the University of Pittsburgh, said at a press conference.
After a series of strokes nine years ago, Heather Randulic lost the use of her left hand and hand. Now, thanks to an implanted device that sends electrical impulses to spinal nerves, she has regained some function. Here, she feeds herself and sorts blocks while the device is on, but has trouble completing these tasks when the stimulation is off. The implant sends electrical impulses to the spinal nerves, bypassing the damaged connection between the brain and the spinal cord. (The devices on her arm are for observation only.)
She and the rest of the team are actively testing the device with other patients, as well as investigating whether combining it with exercise can improve outcomes. Researchers hope it will become widely available because the surgery to implant it is minimally invasive and routine, and the value of the procedure can be clearly demonstrated, which is important to convince insurance companies to cover it.
According to neurologist Bruce Dobkin of the University of California, Los Angeles, who was not involved in the study, the treatment may not be effective for patients with severe mobility impairments. But it could serve as a “new tool to try to maximize the recovery” of stroke patients with more moderate paralysis when combined with other treatments.
For Rendulic, the proven potential of using spinal cord stimulation to treat stroke-induced paralysis gives her hope for the future. “I really hope and pray that it becomes widely available,” she says, “because I know it will change so many lives.”
