“This is very exciting,” said Jason Carmel, a motor neuroscientist at Columbia University who was not involved in the study. “It opens up a potential therapeutic avenue that we haven’t seen before for people with chronic stroke.”
Stroke is the most common cause of disability in adults. all around the world, one in four people over the age of 25 will get it once in a lifetime, and three quarters of them will have long-term mobility impairment in the arms and hands.
A stroke occurs when the blood supply to the brain is blocked or when a blood vessel bursts. Depending on the severity of the brain damage and where it occurs, a stroke can cause certain defects, such as paralysis, weakness, or problems with speaking, thinking, or memory. .
People paralyzed by a stroke are unable to move a muscle or muscle group voluntarily. When the part of the brain that controls movement is damaged, it disrupts communication between the brain and muscles. Patients recovering often do so in the first few months after a stroke. Beyond six months, there is little chance of further improvement. This is the chronic phase of a stroke, when the effects are usually permanent.
Both Rendulic and the other patient are in this stage, and the researchers wanted to see if they could use a mild electrical current delivered to precise locations on the spinal cord to restore function to the arm and muscle. hand or not. The spinal cord is a long tube of nerves in the back that transmits signals from the brain to the rest of the body.
Spinal cord stimulation has been used as a treatment for pain and, in 2018, divide study team published a series of papers showing that it allows some patients paralyzed by spinal cord injury to stand independently and walk with assistive devices for the first time in years. But spinal cord stimulation for upper limb rehabilitation is largely unexplored.
In the latest study, surgeons implanted a pair of thin spaghetti-like metal electrodes along the upper region of the spinal cord in the neck to target the nerves that control the muscles of the arm and hand. hand. The electrode cables are routed outside the skin and connected to a stimulation system in the laboratory.
On the day the researchers turned on the electrical stimulation, Rendulic was able to fully open and grasp her left hand—something she was previously unable to do. “We were all in tears,” she said. “I’ve opened my hand in a way I haven’t done in almost a decade.”
Over four weeks, Rendulic and the other patient performed a series of lab tests. (The second patient, a 47-year-old woman with more severe memory impairment, had a stroke three years ago.) They performed tasks such as moving blocks, picking up marbles, grasping soup cans, and open the lock. Although Rendulic showed more improvement than the other patient, stimulation enhanced arm and hand strength, range of motion, and function in both women. When the device was turned on, Rendulic said she could feel her arm vibrate slightly, but it wasn’t painful.
