New implants let paraplegics surf the web and play computer games
When I greeted Rodney Gorham, age 63, in an online chat session, he replied within seconds: “My pleasure.”
“Are you moving parts of your body as you type?” I asked.
This time, his response came about five minutes later: “I position the cursor with the eye tracking and select the same with moving my ankles.” Gorham, a former sales representative from Melbourne, Australia, living with amyotrophic lateral sclerosis, or ALS, a rare form of Lou Gehrig’s disease that impairs the brain’s nerve cells and the spinal cord, limiting the ability to move. ALS essentially “locks” a person inside their own body. Gorham is conversing with me by typing with his mind only–no fingers in between his brain and his computer.
The brain-computer interface enabling this feat is called the Stentrode. It's the brainchild of Synchron, a company backed by Amazon’s Jeff Bezos and Microsoft cofounder Bill Gates. After Gorham’s neurologist recommended that he try it, he became one of the first volunteers to have an 8mm stent, laced with small electrodes, implanted into his jugular vein and guided by a surgeon into a blood vessel near the part of his brain that controls movement.
After arriving at their destination, these tiny sensors can detect neural activity. They relay these messages through a small receiver implanted under the skin to a computer, which then translates the information into words. This minimally invasive surgery takes a day and is painless, according to Gorham. Recovery time is typically short, about two days.
When a paralyzed patient thinks about trying to move their arms or legs, the motor cortex will fire patterns that are specific to the patient’s thoughts.
When a paralyzed patient such as Gorham thinks about trying to move their arms or legs, the motor cortex will fire patterns that are specific to the patient’s thoughts. This pattern is detected by the Stentrode and relayed to a computer that learns to associate this pattern with the patient’s physical movements. The computer recognizes thoughts about kicking, making a fist and other movements as signals for clicking a mouse or pushing certain letters on a keyboard. An additional eye-tracking device controls the movement of the computer cursor.
The process works on a letter by letter basis. That’s why longer and more nuanced responses often involve some trial and error. “I have been using this for about two years, and I enjoy the sessions,” Gorham typed during our chat session. Zafar Faraz, field clinical engineer at Synchron, sat next to Gorham, providing help when required. Gorham had suffered without internet access, but now he looks forward to surfing the web and playing video games.
Gorham, age 63, has been enjoying Stentrode sessions for about two years.
Rodeny Dekker
The BCI revolution
In the summer of 2021, Synchron became the first company to receive the FDA’s Investigational Device Exemption, which allows research trials on the Stentrode in human patients. This past summer, the company, together with scientists from Icahn School of Medicine at Mount Sinai and the Neurology and Neurosurgery Department at Utrecht University, published a paper offering a framework for how to develop BCIs for patients with severe paralysis – those who can't use their upper limbs to type or use digital devices.
Three months ago, Synchron announced the enrollment of six patients in a study called COMMAND based in the U.S. The company will seek approval next year from the FDA to make the Stentrode available for sale commercially. Meanwhile, other companies are making progress in the field of BCIs. In August, Neuralink announced a $280 million financing round, the biggest fundraiser yet in the field. Last December, Synchron announced a $75 million financing round. “One thing I can promise you, in five years from now, we’re not going to be where we are today. We're going to be in a very different place,” says Elad I. Levy, professor of neurosurgery and radiology at State University of New York in Buffalo.
The risk of hacking exists, always. Cybercriminals, for example, might steal sensitive personal data for financial reasons, blackmailing, or to spread malware to other connected devices while extremist groups could potentially hack BCIs to manipulate individuals into supporting their causes or carrying out actions on their behalf.
“The prospect of bestowing individuals with paralysis a renewed avenue for communication and motor functionality is a step forward in neurotech,” says Hayley Nelson, a neuroscientist and founder of The Academy of Cognitive and Behavioral Neuroscience. “It is an exciting breakthrough in a world of devastating, scary diseases,” says Neil McArthur, a professor of philosophy and director of the Centre for Professional and Applied Ethics at the University of Manitoba. “To connect with the world when you are trapped inside your body is incredible.”
While the benefits for the paraplegic community are promising, the Stentrode’s long-term effectiveness and overall impact needs more research on safety. “Potential risks like inflammation, damage to neural tissue, or unexpected shifts in synaptic transmission due to the implant warrant thorough exploration,” Nelson says.
There are also concens about data privacy concerns and the policies of companies to safeguard information processed through BCIs. “Often, Big Tech is ahead of the regulators because the latter didn’t envisage such a turn of events...and companies take advantage of the lack of legal framework to push forward,” McArthur says. Hacking is another risk. Cybercriminals could steal sensitive personal data for financial reasons, blackmailing, or to spread malware to other connected devices. Extremist groups could potentially hack BCIs to manipulate individuals into supporting their causes or carrying out actions on their behalf.
“We have to protect patient identity, patient safety and patient integrity,” Levy says. “In the same way that we protect our phones or computers from hackers, we have to stay ahead with anti-hacking software.” Even so, Levy thinks the anticipated benefits for the quadriplegic community outweigh the potential risks. “We are on the precipice of an amazing technology. In the future, we would be able to connect patients to peripheral devices that enhance their quality of life.”
In the near future, the Stentrode could enable patients to use the Stentrode to activate their wheelchairs, iPods or voice modulators. Synchron's focus is on using its BCI to help patients with significant mobility restrictions—not to enhance the lives of healthy people without any illnesses. Levy says we are not prepared for the implications of endowing people with superpowers.
I wondered what Gorham thought about that. “Pardon my question, but do you feel like you have sort of transcended human nature, being the first in a big line of cybernetic people doing marvelous things with their mind only?” was my last question to Gorham.
A slight smile formed on his lips. In less than a minute, he typed: “I do a little.”
Too much of this ingredient leads to autoimmune diseases, new research shows. Here's how to cut back.
For more than a century, doctors have warned that too much salt in your diet can lead to high blood pressure, heart disease and stroke - and many of the reasons for these effects are well known. But recently scientists have been looking deeper, into the cellular level, and they are finding additional reasons to minimize sodium intake; it is bad for immune cells, creating patterns of gene expression and activity seen in a variety of autoimmune diseases such as multiple sclerosis, lupus, rheumatoid arthritis, and type-1 diabetes.
Salt is a major part of the ocean from which life evolved on this planet. We carry that legacy in our blood, which tastes salty. It is an important element for conducting electrical signals along nerves and balancing water and metabolites transported throughout our bodies. We need to consume about 500 milligrams of salt each day to maintain these functions, more with exercise and heavy sweating as that is a major way the body loses salt. The problem is that most Americans eating a modern western diet consume about 3400 milligrams, 1.5 teaspoons per day.
Evidence has been accumulating over the last few years that elevated levels of sodium can be harmful to at least some types of immune cells. The first signal came in monocytes, which are immune cells that travel to various tissues in the body, where some of them turn into macrophages, a subset of white blood cells that can directly kill microorganisms and make chemical signals that bring other types of immune cells into play.
Two years ago, Dominik N. Müller from the Max-Delbrueck-Center in Berlin, Germany and Markus Kleinewietfeld, an immunologist at Hasselt University in Belgium, ran a study where they fed people pizza and then measured their immune cell function. “We saw that in any monocytes, metabolic function was down, even after a single salty meal,” Kleinewietfeld says. It seemed to be the cellular equivalent of the sluggish feeling we get after eating too much. The cells were able to recover but more research is needed to answer questions about what dose of sodium causes impairment, how long the damage lasts, and whether there is a cumulative effect of salt toxicity.
Kleinewietfeld and his colleagues have hypothesized that too much salt could be a significant factor in the increased number of autoimmune diseases and allergies over the last few generations.
The latest series of experiments focused on a type of T cell called T regulatory cells, or Tregs. Most T cells release inflammatory mediators to fight pathogens and, once that job is done, Tregs come along to calm down their hyperactive brethren. Failure to do so can result in continued inflammation and possibly autoimmune diseases.
In the lab, Kleinewietfeld and his large team of international collaborators saw that high levels of sodium had a huge effect on Tregs, upregulating 1250 genes and downregulating an additional 1380 genes so that they looked similar to patterns of gene expression seen in autoimmune diseases.
Digging deeper, they found that sodium affected mitochondria, the tiny organelles inside of cells that produce much of its energy. The sodium was interfering with how the mitochondria use oxygen, which resulted in increased levels of an unstable form of oxygen that can damage cell function. The researchers injected those damaged Tregs into mice and found that they impaired the animals' immune function, allowing the inflammation to continue rather than shutting it down.
That finding dovetailed nicely with a 2019 paper in Nature from Navdeep Chandel's lab at Northwestern University, which showed in mice that inhibiting the mitochondrial use of oxygen reduced the ability of Tregs to regulate other T cells. “Mitochondria were controlling directly the immunosuppressive program, they were this master regulator tuning the right amount of genes to give you proper immunosuppression,” Chandel said. “And if you lose that function, then you get autoimmunity.”
Kleinewietfeld's team studied the Treg cells of humans and found that sodium can similarly decrease mitochondrial use of oxygen and immunosuppressive activity. “I would have never predicted that myself,” Chandel says, but now researchers can look at the mitochondria of patients with autoimmune disease and see if their gene expression also changes under high salt conditions. He sees the link between the patterns of gene expression in Tregs generated by high salt exposure and those patterns seen in autoimmune diseases, but he is cautious about claiming a causal effect.
Kleinewietfeld and his colleagues have hypothesized that too much salt could be a significant factor in the increased number of autoimmune diseases and allergies over the last few generations. He says a high salt diet could also have an indirect effect on immune function through the way it affects the gut microbiome and the molecules made by microbes when they break down food. But the research results are too preliminary to say that for sure, much less parse out the role of salt compared with other possible factors. “It is still an exciting journey to try to understand this field,” he says.
Additionally, it is difficult to say precisely how this research in animals and human cell cultures will translate into a whole human body. Individual differences in genetics can affect how the body absorbs, transports, and gets rid of sodium, such that some people are more sensitive to salt than are others.
So how should people apply these research findings to daily life?
Salt is obvious when we sprinkle it on at the table or eat tasty things like potato chips, but we may be unaware of sodium hidden in packaged foods. That's because salt is an easy and cheap way to boost the flavor of foods. And if we do read the labeled salt content on a package, we focus on the number for a single serving, but then eat more than that.
Last September, the U.S. Food and Drug Administration (FDA) began a process to update labels on the content of food, including what is meant by the word “healthy” and how food manufacturers can use the term. Many in the food industry are resisting those proposed changes.
Chandel cautions against trying to counter the effects of salt by reaching for foods or supplements full of antioxidants, which, in theory, could reduce the harmful effects on mitochondria caused by a heavy hand with the salt shaker.
Until labels are updated, it would be prudent to try to reduce sodium intake by cutting down on packaged foods while making your own food at home, where you know just how much salt has been added. The Mayo Clinic offers guidance on how to become more aware of the sodium in your diet and eat less of it.
Chandel thinks many people will struggle with minimizing salt in their diets. It’s similar to the challenge of eating less sugar, in that the body craves both, and it is difficult to fight that. He cautions against trying to counter the effects of salt by reaching for foods or supplements full of antioxidants, which, in theory, could reduce the harmful effects on mitochondria caused by a heavy hand with the salt shaker. “Dietary antioxidants have failed in just about every clinical trial, yet the public continues to take them,” Chandel says. But he is optimistic that research will lead us to a better understanding of how Tregs function, and uncover new targets for treating autoimmune diseases.
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
Here are the promising studies covered in this week's Friday Five, featuring interviews with Dr. Christopher Martens, director of the Delaware Center for Cogntiive Aging Research and professor of kinesiology and applied physiology at the University of Delaware, and Dr. Ilona Matysiak, visiting scholar at Iowa State University and associate professor of sociology at Maria Grzegorzewska University.
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