The Food and Drug Administration has authorized a device that can help stroke patients regain the use of a disabled hand. The device uses signals from the uninjured side of a patient’s brain. NPR’s Jon Hamilton has more.
JON HAMILTON, BYLINE: On a winter night in 2015, Mark Forrest started feeling bad. He thought it was his blood sugar. His wife, Patti, realized he was having a stroke.
MARK FORREST: So we called 911, and off to the hospital I went. And by the time I got there, most of my right side was paralyzed.
HAMILTON: Including his right hand. And more than six months after his stroke, Forrest was still struggling to pull on his socks and button his shirts. What he missed the most, though, was fishing for bass in the rivers and lakes near St. Louis.
M FORREST: I mean, I’m a die-hard fisherman, so that really hurt for me not to be able to do that.
HAMILTON: Forrest even tried cutting down a fishing pole so he could hold it with his left hand, but his right hand wouldn’t reel in the line. So he kept working with a physical therapist, month after month, until he got really frustrated.
M FORREST: I said, how much more am I going to improve? She says, I don’t think you’re going to improve hardly at all.
PATTI FORREST: That was tough.
M FORREST: And that was hard for me to take.
HAMILTON: Around that time, Forrest started talking to Dr. Eric Leuthardt, a brain surgeon at Washington University in St. Louis. For many years, Leuthardt had been puzzled by something he often heard from patients.
ERIC LEUTHARDT: If you talk to a stroke patient, they can imagine moving their hand, they can try to move their hand, but they just can’t actually move it.
HAMILTON: So Leuthardt had been looking for the source of those thoughts and he found them in a surprising place – the side of the brain that had not been injured by the stroke.
LEUTHARDT: So now we’re starting to look at signals being generated on the opposite side of the brain, where there’s still kind of the intent to move and it’s present.
HAMILTON: Leuthardt and his team were able to build a device that used those signals to control a robotic exoskeleton. The device could open and close a patient’s disabled hand for them. But a mechanical hand wasn’t Leuthardt’s ultimate goal. He wanted to help his patients regain the ability to move their own hand, and that meant answering a question.
LEUTHARDT: If somebody can generate a brain signal that’s associated with their desire to move, and the exoskeleton moves it so they’re getting feedback, can we use this device that controls their affected limb to essentially encourage the brain to rewire?