Neurotechnology Breakthrough helps stroke patients use their hands again instantly.

The medical community has a gloomy outlook for the future of strokes: Every fourth person over the age of 25 will have a stroke at some point in their lives, and of those persons, 75% will be permanently impaired in their ability to use their arms and hands.

At the moment, there are no effective ways to treat paralysis in the so-called chronic stage of a stroke, which starts about six months after the stroke. Researchers say that the new technology could give hope to people with disabilities that would have been thought to be permanent in the past.

People who have trouble moving because of a stroke need effective neurorehabilitation solutions more and more quickly.

Even minor stroke-related impairments can cause people to withdraw from their social and professional networks and become severely disabled. Motor impairments in the arm and hand are particularly taxing and can make it difficult to perform even the most basic daily tasks, like writing, eating, and getting dressed.

Today in Nature Medicine, researchers from the University of Pittsburgh and Carnegie Mellon University reported that a neurotechnology capable of instantly stimulating the spinal cord can enhance arm and hand mobility, making it easier for people affected by moderate to severe stroke to perform their routine daily tasks.

Stroke victims who have had a pair of tiny metal electrodes like strands of spaghetti implanted along the neck are able to use their fork and knife to carve a steak for the first time in years because the electrodes stimulate their undamaged brain pathways.

With electrodes positioned on the spinal cord’s surface, spinal cord stimulation technology sends electrical pulses to the spinal cord’s nerve cells, activating them.

High-intensity, long-lasting pain is already being managed with this technology. Spinal cord stimulation has also been shown by numerous research groups from different parts of the globe to be effective in restoring leg mobility after spinal cord damage.

Yet, a far more difficult set of obstacles is presented by the human hand’s exceptional dexterity, the broad range of motion at the shoulder, and the intricacy of the brain impulses governing the arm and hand.

Researchers were given the green light to explore this improved treatment on people after years of comprehensive preclinical investigations combining computer modeling and animal testing in macaque monkeys with partial arm paralysis.

“The sensory nerves from the arm and hand send signals to motor neurons in the spinal cord that control the muscles of the limb,” explains co-senior author Douglas Weber. “By stimulating these sensory nerves,” according to the author, “we can amplify the activity of muscles that have been weakened by stroke. 

“Importantly, the patient retains full control of their movements: The stimulation is assistive and strengthens muscle activation only when patients are trying to move.”

In a series of tests that were tailored to each patient, stimulation helped people do things like move a hollow metal cylinder, pick up common household objects like a can of soup, and open a lock. Clinical evaluations revealed that stimulation of the cervical nerve roots rapidly increases arm and hand strength, range of motion, and functionality.

Interestingly, the benefits of stimulation seemed to continue longer than researchers had anticipated and lasted even after the device was taken out, indicating that it may be employed as a restorative and helpful technique for upper limb rehabilitation. In fact, the stimulation’s immediate effects make it possible to provide vigorous physical exercise, which might then result in even better long-term gains in the absence of the stimulation.

Going ahead, researchers continue to register more study subjects in order to comprehend which stroke patients would profit the most from this treatment and how to tailor stimulation procedures for various degrees of severity.

Also, a new company called Reach Neuro that was created by researchers from Pitt and CMU is aiming to implement the treatment in clinical settings.

“Thanks to years of preclinical research building up to this point, we have developed a practical, easy-to-use stimulation protocol adapting existing FDA-approved clinical technologies that could be easily translated to the hospital and quickly moved from the lab to the clinic,” adds corresponding and co-senior author Marco Capogrosso.

Source: 10.1038/s41591-022-02202-6

Image Credit: TIM BETLER, UPMC AND THE UNIVERSITY OF PITTSBURGH SCHOOLS OF THE HEALTH SCIENCES