A new treatment could restore some mobility in people with debilitating strokes

Sitting in an exam room, surrounded by doctors and scientists, Heather Rendulic opened her left hand for the first time since suffering a series of strokes nine years ago when she was in her early 20s.

“It was an amazing feeling to be able to do it again,” Rendulic says. “This is not something I ever thought would be possible.”

But immediately after the device surgically implanted in his spinal cord sent electrical impulses, Rendulic not only opened his hand, but also showed other marked improvements in the mobility of his arm, researchers report on February 20. Nature Medicine. “We all start crying,” Marcus Capogrosso, a neuroscientist at the University of Pittsburgh, said in a February 15 news conference. “We didn’t really expect this to work as well as it did.”

The approach is similar to that used in patients with recent paralytic spinal cord injuries (SN: 08/03/22). It represents a new technique that promises to restore voluntary movement to those left with upper body paralysis following strokes, the team says.

A stroke occurs when blood supply to parts of the brain is cut off, often causing short-term or long-term problems with movement, speech and vision. A wound is the first, and often unconscious, cause of paralysis; in the United States alone, 5 million people live with some form of motor disability due to stroke. While physical therapy can provide some improvements, no treatment exists to help patients regain full control of their limbs — and lives.

Strokes cause paralysis because the connection between the brain and the spinal cord is damaged; The spinal cord is trying to tell the brain to move certain muscles, but the message is confused.

So, using already existing techniques for spinal anesthetic injections, the team found an electrical device that can be placed in the spinal cord to stimulate the nerves there. An estimate “doesn’t hurt anything,” says Rendulic. “It doesn’t feel like a tremor.”

By aligning the electrodes of the device with the sensory nerves, “we can increase the activity of muscles that have been weakened by stroke,” Douglas Weber, an engineer and neuroscientist at Carnegie Mellon University in Pittsburgh, said at a news conference. Pulses from these electrodes seek to amplify the signals from the brain, so that the sensory nerves respond by activating the muscles, restoring the body’s voluntary control to the patient.

Rendulic and the other patient in the study both showed improvement in mobility tasks, including pulling a spiral, opening a lock and grip, and messing while on the device. Continuous electrical stimulation treatment sessions were held for four hours a day, five days a week, over 29 days, and the improvements continued as long as four weeks after the treatment stopped. This makes the researchers optimistic that they could achieve even stronger results if the treatment was matched with intensive physical training, Elvira Pirondini, a neuroscientist at the University of Pittsburgh, said at a news conference.

She and the rest of the team are actively testing the device with other patients, and are also exploring whether combining it with physical training can improve outcomes. The researchers hope that it will be widely open because the surgery is minimally invasive and routine, and the procedure can be clearly demonstrated, which is important to convince insurance companies to cover it.

The treatment may not work well for patients with severe mobility issues, says UCLA neurologist Bruce Dobkin, who was not involved in the study. But he could use “a new tool to try to increase the recovery” of stroke paralysis with a controller, in combination with other therapies.

For Rendulic, the potentially proven use of spinal cord stimulation to treat paralysis from stroke offers hope for the future. “I really hope and pray that this happens,” he said, “because I know it will change so many lives.”