Paralysis is the loss of muscle function in either part of, or the majority of the body, depending on the severity of the injury. From the waist down, paralysis is called paraplegia and renders the body unable to walk. This occurs when the body’s spinal cord is damaged, as a result of, for example, a car accident or disease, such as a tumor. Nerve cells send signals to the brain via the body’s spinal cord, which is made of nervous tissue, and is, along with the brain, a part of the central nervous system. Vehicle-related accidents are the leading cause of paraplegia cases, with 38.3% of paraplegia injuries from 2015-2019 being caused by motor accidents [Spinal Cord Inc., 2019].
In recent years, there have been many promising ideas that could help deal with the problem of paraplegia, a Stentrode being one of them. Stentrodes, inspired by stents which are usually used to hold closing blood vessels open, are 3 cm devices that will change the lives of people with paraplegia. The stentrode will rest inside a blood vessel on top of the motor cortex, the part of the brain where nerve impulses that cause deliberate muscle actions come from. This should enable the stentrode to record the frequencies the brain emits and to transfer those signals into movements. The Stentrode has many possibilities, and together with the exoskeletons is called a Bionic spinal cord. In 2016, the bionic spinal cord was tested on sheep, and it successfully recorded the signals the motor cortex emitted for the 190 days it was tested. Since sheep brains are very similar to human brains, the future of the Stentrode is very bright and may help patients suffering from paraplegia walk again.
The idea of a stentrode was invented by Thomas Oxley, an Australian neurology resident, and his colleague, Dr Nicholas Opie, an engineer. The reason why this technology will have a global impact is because of its uniqueness in the way it is implanted in the body. So far there have been three ways to measure brain frequencies, but all three have fallen short.
- Surface electrodes are placed on the scalp and are non-invasive, but you have to put each one on separately, and they do not receive enough signals as the skull and brain block them.
- Epidural electrodes are placed directly on the brain and require a large part of the skull to be removed to perform the surgery, but they do receive high-frequency signals. But the person with the Epidural electrodes will have to have wires semi-permanently coming out of their head.
- Penetrating electrodes still requires surgery to remove a part of the skull, but instead of being wires, it is a small chip that is shot into the brain. Very high-frequency signals are received, but they cause tissue trauma and are not FDA (Food and Drug Administration) approved.
The Stentrode, however, will enter through a cut in the neck and make its way through a blood vessel to the brain. It will then rest in the blood vessel that is directly on top of the motor cortex, receiving very high-quality signals without open brain surgery. This simple procedure can be done in under 30 minutes, as attested by the fact that Dr. Nicholas Opie completed it on a sheep despite not being a surgeon in this time bracket.
The Stentrode goes hand in hand with exoskeletons, a sort of external covering for the body that when connected to the Stentrode, will be able to move with a single thought. Just like a healthy, able body, with a single thought, the paraplegic body would be able to walk as though they had no paralysis. Although Stentrode’s main purpose will be to help patients with paraplegia walk again, there are many other possibilities that will come with it. For example, using this technology, an old lady with quadriplegia (meaning she couldn’t use her arms as well as her legs), was able to control the cursor on a screen and type out a story. This means she wrote a story using her thoughts. In the future when this technology gets updated, the possibilities will be endless. This will enable people with paraplegia to go back out into their communities, able to walk and communicate just as they did before.
Morally the Stentrode is incorrect because of animal testing. The Stentrode was tested on sheep because of their similar brain structure to humans, and many people may be opposed to this. 30 sheep were tested and had their results recorded over a period of 190 days. The conditions the sheep were in during these recordings were not mentioned, suggesting that they may have been in cramped conditions or forced into routines.
The Stentrode was supposed to have been tested on humans in 2018, but nothing mentioning any sort of human trial has come out on the internet, which implies that either the tests went horribly wrong (which is unlikely) or that they did not happen for some reason. In a Youtube video made in May 2017, Nicholas Opie is very sure that the trials will go through and even says: “And hopefully, when that (the human trials) happens I’ll be invited back (to the Convergence Science Network) to give you updates…”. Nicholas did not end up making that follow-up video, adding to the common belief that the tests did not happen. A reason why they might not have occurred is that they have possibly not yet been approved by the FDA (Food and Drug Administration). Because the human trials have supposedly not occurred yet, this means that it is unsure whether the Stentrode works or not on humans, and whether the Stentrode will continue to receive brain frequencies after a period of time.
This technology is still very new, and although so far the positives by far outweigh the negatives - yes it was tested on sheep, but in the long run, what is a small amount of animal cruelty compared to thousands of paraplegic people being able to walk again - some things could drastically change in the future. As mentioned in the previous paragraph, the Stentrode has not yet been trialed on by humans, and there is doubt as to whether it will actually work. This is a rather large factor that must be mentioned as it defines the future of the Stentrode.
In my opinion, this technology should be tested on humans as soon as possible, because yes, the sheep do have similar brains to humans, but how can that prove that there will not be any side effects humans will have? I believe that there would be many people willing to try the Stentrode, despite the possible risks. If the human trials, after a year or so, are effective and successful, then this technology should definitely be implemented into Australian practices as soon as possible because the only impactful negative is about whether it will be successful on humans, which will then be answered by then.