People with spinal cord injuries have been hearing for decades there is research that may help them walk again that is right around the corner, but the latest epidural stimulation study was done by Dr. Gregoire Courtine at the Swiss federal institute of technology, and Dr. Joycelyn Bloch from Lausanne University Hospital, gives hope that people with complete injuries could be walking again within the next 5 to 10 years.
Epidural stimulation is nothing new. Before being applied to people with spinal cord injuries by Dr. Susan Harkema at the University of Louisville, which she began to do in 2009, it was used to help people with back pain. Dr. Harkema’s study was the first however and it infused some much-needed excitement into the SCI research world. All of her participants however had some sensation in their lower extremities in order to be approved for the trial.
The STIMO clinical trial done by Dr. Courtine and Dr. Bloch however used patients that have zero sensation and movement below their level of injury, and most were a few years past their injuries. Each participant had a 16-electron device implanted into the epidural space in their spinal column. This electrode array was redesigned to be wider and longer than those used in previous studies.
The researchers believe this electrode array is what enabled them to access the entire area of the spinal cord needed to stimulate the trunk and leg muscles. This is exciting because, within hours of the surgery where electrodes were implanted, all participants were able to walk again using either body weight support from parallel bars or an overhead harness.
Unfortunately, epidural stimulation cannot return sensation. Although all participants were able to stand and walk again with the stimulator turned on, no one was able to receive a return of sensation. Important bodily functions, however, from bladder and bowel to sexual function, have been reported to return to those who have undergone epidural simulation.
Additionally, researchers have developed a brand new algorithm to send the correct pulses to the muscles to help the patients do a variety of activities like walking, climbing stairs, and swimming. In previous studies, researchers relied on the patient's brain signals for the input to the electrodes. With this new study, however, they bypass the need for the patient's brain signals and instead rely completely on the algorithm.
There's a pacemaker that is implanted into the stomach to help operate the entire system, and in the future when this is commercially available, the pacemaker will need to be replaced every 9 years. Researchers say that the electrodes however will not need to be replaced, and should last a lifetime.
Their next plan is to conduct an even larger clinical trial in the US. In order to be quickly approved by the FDA, they need to show its effectiveness. Their hope is that this surgery and implantable devices will be commercially available in the next 3 to 5 years for people with spinal cord injuries. They say this often, but this study seems to be different.
To see people with complete injuries not only stand but walk using a walker, walking through towns, and some even climbing stairs again, is monumental. Although these individuals are walking on legs they cannot feel, it still is an amazing feat of engineering. It looks more and more as though an engineering solution will be the ultimate treatment for spinal cord injuries.
https://www.cnn.com/2022/02/07/health/spinal-cord-stimulation-study/index.html
