Electrical stimulation has enabled two people who had suffered a stroke and had one of their arms and one of their hands paralyzed to recover movement immediately. The key lies in a pair of fine metal electrodes implanted along the neck that activate intact neural circuits.
Details of this clinical trial are explained in a paper published in Nature Medicine, and the data provide preliminary evidence of the potential for spinal cord stimulation as a restorative approach to upper extremity recovery after trauma. stroke.
Nearly three-quarters of people who experience a stroke or stroke have long-lasting deficits in motor control of the arms and hands. Such deficits persist in part due to the limitations of current neurorehabilitation approaches.
Epidural spinal cord stimulation, a clinically approved technology that delivers electrical stimulation to the spinal cord, has shown promise in the recovery of motor function in the legs in people with spinal cord injury. Despite these encouraging findings, its role in upper extremity recovery has been largely unexplored.
What researchers from the University of Pittsburgh and Carnegie Mellon University have now carried out is to investigate the role of this therapy applied for 29 days in the cervical spinal cord of two women, aged 31 and 47, with chronic weakness in the upper extremities after a stroke.
A pair of thin, spaghetti-like metal electrodes were implanted along the neck to activate intact neural circuitry, allowing stroke patients to fully open and close your fist, raise your arm above your head, or use a fork and knife to cut a piece of steak for the first time in years.
“We found that electrical stimulation of specific regions of the spinal cord allows patients to move their arm in ways they are unable to without stimulation. And perhaps even more interesting, we found that after a few weeks of use, some of these improvements persist when the stimulation is turned off, pointing to exciting avenues for future stroke therapies,” says Marco Capogrosso, Lead Of the investigation
Currently, no treatment is effective in treating paralysis in the so-called chronic phase of stroke, which begins approximately six months after the stroke. According to the researchers, the new technology may offer hope to people living with disabilities that would otherwise be considered permanent.
“The creation of effective neurorehabilitation solutions for people affected by movement impairments after stroke is increasingly urgent,” says co-lead author Elvira Pirondini. “Even the raised deficits resulting from a stroke can isolate to people in social and professional life and become very debilitating, with motor deficiencies in the arm and hand being especially burdensome and preventing simple daily activities such as writing, eating and dressing”.
In a series of tests tailored to each patient, the stimulation allowed them to perform tasks of varying complexity, from moving a hollow metal cylinder to grasping common household objects, such as a can of soup, and picking a lock. Clinical evaluations have shown that targeted stimulation of the cervical nerve roots immediately improves arm and hand strength, range of motion, and function.
Unexpectedly, the effects of the stimulation appear to be longer lasting than scientists originally thought and persist even after the device is removed, suggesting that it could be used as a assist and restore method for the recovery of the upper extremities. In fact, the immediate effects of stimulation allow for the administration of intense physical training which, in turn, could lead to even greater long-term improvements in the absence of stimulation.