Brain Computer Interface for Spinal Cord Injury
Last Updated: 28 February 2019
Computers and A Complete Spinal Cord Injury
Brain computer interface for spinal cord injury could finally move us forward after thousands of years of clinical stagnation.
Since the early days of medicine, the classic teaching in neuroscience about spinal cord injuries (SCI) has been quite pessimistic. Even modern neuroscience isn’t much different. And for good reason, it seems.
A complete spinal cord injury is one that occurs with total loss of sensory and motor function below the level of the injury. It is considered particularly hopeless, because the chances of a full functional recovery are minimal to zero.
Patients with a complete spinal cord injury usually do not die directly from it. One reason is because spinal cord injuries are rarely isolated events. Brain injuries and trauma to other organs or vital vasculature is so common that clinicians should always suspect them in association with a spinal cord injury.
Making matters worse, those who survive the initial insult are at higher risk of succumbing to the sequelae. Respiratory failure, skin breakdown, blood clots, pneumonia, renal failure caused by pyelonephritis from a neurogenic bladder, and a host of other deadly problems are always lurking around the corner.
The nature of neurologic injuries is to evolve over time, especially in the hyperacute and acute phases. Like other traumatized organs, the acutely injured spinal cord is prone to swelling.
This causes worsening damage by the very structures meant to protect it, often requiring immediate intervention. But even when modern medicine is first on the scene, there is no guarantee of a good outcome.
A Pessimistic History of Complete Spinal Cord Injury
Even in classical times, thought leaders recommended reduction and decompression of the swollen cord with a laminectomy if some motor or sensory function was spared. How they confirmed they were on the correct operative level without fluoroscopy baffles me. Though, without the same medico-legal worries, I’m not surprised.
However, even in these ‘dark’ times, people easily recognized the bleak future of someone with a complete spinal cord injury. With modern intensive care units and advances in medical science, spinal cord injury is less fatal today, but recovery of function remains largely similar to those in the dark ages.
Since the times of Hippocrates until today, the prognosis hasn’t changed all that much. That said, it’s not hard to see why the medical community is so pessimistic about complete spinal cord injuries.
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Brain Computer Interface for Spinal Cord Injury
What about those who do not recover their ability to walk, use their arms, or breathe on their own again? Or those who have made minimal functional recovery before plateauing? What about patients with complete cord transections where the point of surgery is simply mechanical stabilization?
This article is not meant as a downer, I promise. Though parts of it were written while I was on neurosurgical trauma call. After seeing more than my fair share of these types of injuries, along with the remarkable recoveries and disappointing outcomes, I got to writing.
This was also a major theme of 2018’s Congress of Neurological Surgeons annual meeting, not to mention a possible key shift in FDA priorities.
More and more, we look to ‘new’ technology to solve so many of our old problems.
Twenty years ago, carrying a camera, alarm clock, gaming device, GPS, and cell phone in your pocket at once was lunacy. Now, you have a sweet smartphone. Want awesome CME but don’t want to leave your house? Boom. Need to remove a precariously positioned brain tumor but don’t have x-ray vision? Try augmented reality for neurosurgery.
A recent study published in the New England Journal of Medicine suggests there may be less hopelessness than we alluded to above. They describe four patients with chronic, complete motor spinal cord injuries who regained the ability to stand independently after the intervention.
This recovery came after an intensive, 15-week rehabilitation program combined with simultaneous epidural spinal cord stimulation.
We should note that the four patients in the study suffered from injuries that were technically incomplete spinal cord injuries because at least some sensation was spared. Remember complete spinal cord injuries have total loss of all motor AND sensory function below the level of injury.
How Does a Brain Computer Interface Work?
It may sound like something from a science fiction novel (one you should totally buy and read, by the way), but a brain-computer interface could provide hope for those with a complete spinal cord injury. In fact, it has been an emerging solution since 1973 when Jacques Vidal first called it.
After all, what is the spinal cord besides a conduit for transmitting electrical signals from the brain to the arms, legs, and organs? What if you could bypass the damaged area and send the signals to a robotic arm that would never lose another arm-wrestling match?
Brain computer interface for spinal cord injury, if shown to be safe and effective, may be a game-changer. It may also have applications to other neurological conditions like amyotrophic lateral sclerosis, stroke, or cerebral palsy.
Instead of sending signals down the usual neuromuscular pathways, usually the spinal cord’s job, a brain-computer interface receives those same signals and directs them up from the brain.
The signal processing starts with a small “chip” implanted into the cerebral motor cortex.
This component has several short probes that project into the cortex to sit among the neurons. The probes receive signals from those nearby neurons when they emit impulses. The chip then transmits those impulses to an amplifier. The amplifier is (currently) a tremendously unwieldy extracranial mass that sends these impulses into a computer.
Finally, the computer analyzes the signals and translates them into commands fulfilled by a digital or mechanical output mechanism.
This means patients can essentially use their thoughts to control a robot arm, move a cursor on the screen, use the internet, communicate, play videogames, and do many other things previously thought impossible.
The Problem of Scale... Among Others
So why isn’t a brain computer interface standard of care for all patients with complete spinal cord injury?
First, cool YouTube videos always forget to mention the side effects or issues with such exciting advances. Fortunately, adverse events directly related to the device seem to be rare, at least conceptually. However, the technology itself has some limitations.
First, studies need to demonstrate safety and efficacy in the intended population. Second, these systems may be too burdensome for patients to use on a regular basis. I don’t imagine having a large amplifier poking out of your head would be particularly comfortable.
Lastly, the technology just has to work. If your cursor lags a bit on your computer, you might get a little frustrated. However, if your brain computer interface is controlling a motor vehicle, your first technical failure may be your last.
That’s not to say the future isn’t promising in this area. DARPA, the United States government’s answer to Elon Musk’s imagination on LSD and steroids, recently funded six major brain computer interface projects. One of which was founded by Elon Musk while another is Facebook’s doing.
These systems may have a relatively long road until they are mainstream, but it might not be as long as you think.
If you were ever afraid of the government and big corporations putting “chips” in your brain, now is the time to break out your aluminum tin-foil hat.
Benefits of Studying the Brain Computer Interface for Spinal Cord Injury
We discuss the technology of brain computer interface for spinal cord injury today for more than one reason. Yes, it’s interesting, but it also speaks to something more. There is another level of learning, knowledge, and ignorance we share in medicine. It is easy to fall into a routine where we do our day jobs and treat patients the same way we did five, ten, or twenty years ago.
We can all use a reminder to learn something new from time to time. It may sound daunting to stretch outside your cognitive comfort zone, but once you do, the lifelong learner in you will find the excitement.
One way to do that is to go back and take a refresher on the basics. For example, here’s a primer on neuroimaging if you didn’t know what you were seeing at the top of the page.
Another is to find new, quality sources of continuing medical education (CME) and interesting ways to spend your CME money.
A favorite of ours is Board Vitals, which offers unmatched board-review, MOC, and CME with advanced analytics to help you track your progress. You can also get up to a $2000 gift card with certain CME packages.
You can also stay up to date with the latest Practical Reviews in Neurosurgery, which also comes with the option of getting your CME with gift card offers.
The only downside is that we are not aware of any brain computer interface linking your noggin with Board Vitals or Oakstone quite yet. We’re sure it’s just a matter of time, though.
Statement from FDA Commissioner Scott Gottlieb, M.D., on efforts to spur development of innovative devices, including new advancements in novel brain implants, that can help patients with paralysis or amputation gain mobility. U.S. Food and Drug Administration. https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm631844.htm.
Recovery of Over-Ground Walking after Chronic Motor Complete Spinal Cord Injury: NEJM. New England Journal of Medicine. https://www.nejm.org/doi/full/10.1056/NEJMoa1803588.
Shih JJ, Krusienski DJ, Wolpaw JR. Brain-Computer Interfaces in Medicine. Mayo Clinic Proceedings. 2012;87(3):268-279. doi:10.1016/j.mayocp.2011.12.008
Silver JR. History of the treatment of spinal injuries. Postgraduate Medical Journal. https://pmj.bmj.com/content/81/952/108. Published February 1, 2005.
Vidal JJ. Toward Direct Brain-Computer Communication. Annual Review of Biophysics and Bioengineering. 1973;2(1):157-180. doi:10.1146/annurev.bb.02.060173.001105