Spinal cord stimulation helps stroke survivors regain arm mobility

Two people with stroke-induced upper body paralysis partially regained arm movement after electrical stimulation of spinal cord neurons.

Electrical stimulation of spinal neurons in two people with upper body paralysis due to a stroke helped them partially restore hand function. This is the first time that spinal cord stimulation has been used to treat upper body paralysis in humans.

Stroke is the leading cause of paralysis in the US. It can permanently dampen brain signals so that neurons in the spinal cord can’t detect them and cause them to move. “We thought, what if there was a way to increase the receptivity of the spinal circuits so that they could suddenly hear more?” says Marco Capogrosso of the University of Pittsburgh at Pennsylvania.

He and his colleagues surgically placed eight electrical nodes on each side of the spinal cord in two people with stroke-induced upper body paralysis. It’s a minimally invasive operation, he says, in which eight connected electrodes are inserted through a spaghetti-sized puncture using a catheter. When active, the nodes electrically stimulated the neurons in the spine that control hand movements, making them more sensitive to brain signals.

Participants completed tasks measuring arm strength, movement, and function five days a week for four weeks. When the electrodes were turned on, the first participant’s hand grip strength increased by 40%, and the second participant’s grip strength increased by 108%. Both were able to reach objects in the virtual reality environment, which they could not with the stimulation turned off.

The first participant was also able to open the lock and use the utensils to eat on their own for the first time in nine years when the stimulation was turned on. The second participant could not complete these tasks, as her paralysis was more severe, but she was able to grab, lift, and place a metal cylinder on a wooden rod, which she could not do without stimulation.

“What we didn’t expect was that some recovery was maintained even after pacing was stopped,” says Capogrosso. Participants were assessed before the study and four weeks after the last stimulation, which measured motor recovery on a 66-point scale. The result of the first participant increased by 11 points, and the second – by 2 points.

“There is huge potential for this to become a stroke therapy, especially since the technology we are using is already approved for other diseases,” says Capogrosso.

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