Imagine that you are one of the hundreds of millions of people who suffer from depression. Medication hasn't helped you, so you're looking for another treatment option. Something powerful enough to change your mood as soon as you need a lift.
"If a participant experiences a personality change, does this change who they are or dehumanize them by altering their nature?"
Enter deep brain stimulation: a type of therapy in which one or more electrodes are inserted into your brain and connected to a surgically implanted, battery-operated medical device in your chest. This device, which is approximately the size of a stopwatch, sends electric pulses to a targeted region of your brain. The idea is to control a variety of neurological symptoms that can't be adequately managed by drugs.
Over the last twenty years, deep brain stimulation, known as DBS, has become an efficient and safe alternative for the treatment of chronic neurological diseases such as epilepsy, Parkinson's disease and neuropathic pain. According to the International Neuromodulation Society, there have been more than 80,000 deep brain stimulation implants performed around the world.
The Food and Drug Administration approved DBS as a treatment for essential tremor and Parkinson's in 1997, dystonia in 2003 and obsessive compulsive disorder in 2009. Since doctors can use drugs and treatments "off-label" (not approved by the FDA) to treat patients with any disease, DBS is now also being investigated as a treatment for chronic pain, PTSD and major depression.
And these new applications are raising profound ethical questions about individuality, personality, and even what it means to be human.
"These patients are essentially having a computer that can modify and influence emotional processing, mood and motor outputs inserted into the brain," said Gabriel Lazaro-Munoz, an assistant professor at The Center for Medical Ethics and Health Policy at Baylor College of Medicine. "These responses define us as human beings and dictate our autonomy. If a participant experiences a personality change, does this change who they are or dehumanize them by altering their nature? These are some of the questions we have to consider."
"When we are not in control of ourselves, are we ourselves?"
The U.S. government has similar concerns about DBS. The National Institutes of Health recently awarded grants to study the neuroethical issues surrounding the use of DBS in neuropsychiatric and movement disorders and appropriate consent for brain research. The grants are part of the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative. Walter Koroshetz, director of NIH's National Institute of Neurological Disorders and Stroke said, "Neuroscience is rapidly moving toward a new frontier of research on human brains that may have long-lasting and unforeseen effects. These new awards signal our commitment to research conducted in a responsible way as to anticipate all potential consequences, and to ensure that research subjects have a clear understanding of the potential benefits and risks of participating in studies."
Dr. Lazaro-Munoz's Center was awarded one of the grants to identify and evaluate the ethical, legal and social concerns with adaptive deep brain stimulation (aDBS) technologies. Adaptive DBS is a relatively new version of the technology that enables recording of brain cell activity that is then used to regulate the brain in real time. He and his team will closely observe researchers conducting aDBS studies and administering in-depth interviews to trial participants, their caregivers, and researchers, as well as individuals who declined to participate in such studies. The goal is to gain a better understanding of the ethical concerns at stake in order to guide responsible research.
Dr. Lazaro-Munoz said one of the concerns is dehumanization. "By using this technology are we compromising what makes us human? When we are not in control of ourselves, are we ourselves?" He notes that similar concerns were raised about pharmaceutical treatments for illnesses. "Both change behaviors and emotional processing. However, there is a difference. Culturally we are more used to using drugs, not implanting devices into brain and computer interfaces. Many people think of it as science fiction."
The changes in behavior due to DBS can be dramatic, perhaps none more so than with Parkinson's disease; patients may see their chronic tremors suddenly vanish.
Pills for OCD and depression take longer than DBS to see significant improvement, sometimes months. "A DBS device is either on or off. And patients and families see changes immediately," Dr. Lazaro-Munoz said. "Family members are often startled by these changes, as are the patients." He's observed that patients feel more in control with pills because they can alter and "play" with the dose or even skip a dose.
The changes in behavior due to DBS can be dramatic, perhaps none more so than with Parkinson's disease; patients may see their chronic tremors suddenly vanish, like in this must-see video.
But surgical procedures to treat motor symptoms are also increasingly being implicated as a cause of behavioral changes, both positive and negative, in patients with Parkinson's. The personality changes reported in patients who undergo DBS include hypermania, pathological gambling, hypersexuality, impulsivity and aggressiveness. One patient who suffered from OCD fell in love with the music of Johnny Cash when his brain was stimulated. On the positive side, patients report memory enhancement.
One patient who is pleased with DBS is Greg Barstead, who was diagnosed with Parkinson's in 2003, when he was the president of Colonial Penn Life Insurance Company. He also has dystonia, which affects his neck and shoulders. Barstead said that DBS has been helpful for a range of symptoms: "My shoulder is a lot less stiff and my neck hurts less. And my tremors are under control. It is not perfect, as it doesn't relieve all the Parkinson's symptoms, but it does enough of a good job that both my wife and I are very happy I had DBS."
"We are not exactly sure what part of the brain causes depression. Doctors have not identified where to implant the device."
He said he hasn't noticed any personality changes, but noted that the disease itself can cause such changes. In fact, studies have shown that it can cause many psychiatric problems including depression and hallucinations. And, approximately a third of Parkinson's patients develop dementia.
Arthur L. Caplan, founding head of the Division of Medical Ethics at NYU School of Medicine, notes that unlike psychosurgery, DBS can be turned on and off and the device can be removed. "There are less ethical concerns around treating patients with Parkinson's disease than other illnesses because surgeons know exactly where to implant the device and have many years of experience with it," he said, adding that he is concerned about using DBS for other illnesses, such as depression. "We are not exactly sure what part of the brain causes depression. Doctors have not identified where to implant the device. And I would certainly not advocate its use in patients with mild depression."
Dr. Lazaro-Munoz said of the personality changes possible with DBS, physicians need to consider how the patients were functioning without it. "Patients who are candidates for DBS typically used many medications as well as psychotherapy before opting for DBS," he explained. "To me, the question is what is the net result of using this technology? Does the patient have regrets? Are the changes in personality significant or not? Although most DBS patients report being happy they underwent the procedure, some say they don't feel like themselves after DBS. Others feel they are more like themselves, especially if there are dramatic improvements in movement problems or relief of OCD symptoms."
And then there is the question of money. The costs of DBS are covered by most insurance companies and Medicare only for FDA-approved targets like Parkinson's. Off-label uses are not covered, at least for now.
Caplan reminds people that DBS devices are manufactured by companies that are interested in making money and the average cost per treatment is around $50,000. "I am interested in seeing DBS move forward," he said. "But we must be careful and not allow industry to make it go too fast, or be used on too many people, before we know it is effective."
Glioblastoma is an aggressive and deadly brain cancer, causing more than 10,000 deaths in the US per year. In the last 30 years there has only been limited improvement in the survival rate despite advances in radiation therapy and chemotherapy. Today the typical survival rate is just 14 months and that extra time is spent suffering from the adverse and often brutal effects of radiation and chemotherapy.
Scientists are trying to design more effective treatments for glioblastoma with fewer side effects. Now, a team at the Department of Neurosurgery at Houston Methodist Hospital has created a magnetic helmet-based treatment called oncomagnetic therapy: a promising non-invasive treatment for shrinking cancerous tumors. In the first patient tried, the device was able to reduce the tumor of a glioblastoma patient by 31%. The researchers caution, however, that much more research is needed to determine its safety and effectiveness.
How It Works
“The whole idea originally came from a conversation I had with General Norman Schwarzkopf, a supposedly brilliant military strategist,” says Dr David Baskin, professor of neurosurgery and leader of the effort at Houston Methodist. “I asked him what is the secret to your success and he said, ‘Energy. Take out the power grid and the enemy can't communicate.’ So I thought about what supplies [energy to] cancer, especially brain cancer.”
Baskin came up with the idea of targeting the mitochondria, which process and produce energy for cancer cells.
This is the most exciting thing in glioblastoma treatment I've seen since I've been a neurosurgeon but it is very preliminary.”
The magnetic helmet creates a powerful oscillating magnetic field. At a set range of frequencies and timings, it disrupts the flow of electrons in the mitochondria of cancer cells. This leads to a release of certain chemicals called ROS (Reactive Oxygen Species). In normal cells, this excess ROS is much lower, and is neutralized by other chemicals called antioxidants.
However, cancer cells already have more ROS: they grow rapidly and uncontrollably so their mitochondria need to produce more energy which in turn generates more ROS. By using the powerful magnetic field, levels of ROS get so high that the malignant cells are torn apart.
The biggest challenge was working out the specific range of frequencies and timing parameters they needed to use to kill cancer cells. It took skill, intuition, luck and lots of experiments. The helmet could theoretically be used to treat all types of glioblastoma.
Developing the magnetic helmet was a collaborative process. Dr Santosh Helekar is a neuroscientist at Houston Methodist Research Institute and the director of oncomagnetics (magnetic cancer therapies) at the Peak Center in Houston Methodist Hospital. His previous invention with colleagues gave the team a starting point to build on. “About 7 years back I developed a portable brain magnetic stimulation device to conduct brain research,” Helekar says. “We [then] conducted a pilot clinical trial in stroke patients. The results were promising.”
Helekar presented his findings to neurosurgeons including Baskin. They decided to collaborate. With a team of scientists behind them, they modified the device to kill cancer cells.
The magnetic helmet studied for treatment of glioblastoma
Dr. David Baskin
After success in the lab, the team got FDA approval to conduct a compassionate trial in a 53-year-old man with end-stage glioblastoma. He had tried every other treatment available. But within 30 days of using the magnetic helmet his tumor shrank by 31%.
Sadly, 36 days into the treatment, the patient had an unrelated head injury due to a fall. The treatment was paused and he later died of the injury. Autopsy results of his brain highlighted the dramatic reduction in tumor cells.
Baskin says, “This is the most exciting thing in glioblastoma treatment I've seen since I've been a neurosurgeon but it is very preliminary.”
The helmet is part of a growing number of non-invasive cancer treatments. One device that is currently being used by glioblastoma patients is Optune. It uses electric fields called tumor treating fields to slow down cell division and has been through a successful phase 3 clinical trial.
The magnetic helmet has the promise to be another useful non-invasive treatment according to Professor Gabriel Zada, a neurosurgeon and director of the USC Brain Tumor Center. “We're learning that various electromagnetic fields and tumor treating fields appear to play a role in glioblastoma. So there is some precedent for this though the tumor treating fields work a little differently. I think there is major potential for it to be effective but of course it will require some trials.”
Professor Jonathan Sherman, a neurosurgeon and director of neuro-oncology at West Virginia University, reiterates the need for further testing. “It sounds interesting but it’s too early to tell what kind of long-term efficacy you get. We do not have enough data. Also if you’re disrupting [the magnetic field] you could negatively impact a patient. You could be affecting the normal conduction of electromagnetic activity in the brain.”
The team is currently extending their research. They are now testing the treatment in two other patients with end-stage glioblastoma. The immediate challenge is getting FDA approval for those at an earlier stage of the disease who are more likely to benefit.
Baskin and the team are designing a clinical trial in the U.S., .U.K. and Germany. After positive results in cell cultures, they’re in negotiations to collaborate with other researchers in using the technology for lung and breast cancer. With breast cancer, the soft tissue is easier to access so a magnetic device could be worn over the breast.
“My hope is to develop a treatment to treat and hopefully cure glioblastoma without radiation or chemotherapy,” Baskin says. “We're onto a strategy that could make a huge difference for patients with this disease and probably for patients with many other forms of cancer.”
Astronauts at the International Space Station today depend on pre-packaged, freeze-dried food, plus some fresh produce thanks to regular resupply missions. This supply chain, however, will not be available on trips further out, such as the moon or Mars. So what are astronauts on long missions going to eat?
Going by the options available now, says Christel Paille, an engineer at the European Space Agency, a lunar expedition is likely to have only dehydrated foods. “So no more fresh product, and a limited amount of already hydrated product in cans.”
For the Mars mission, the situation is a bit more complex, she says. Prepackaged food could still constitute most of their food, “but combined with [on site] production of certain food products…to get them fresh.” A Mars mission isn’t right around the corner, but scientists are currently working on solutions for how to feed those astronauts. A number of boundary-pushing efforts are now underway.
The logistics of growing plants in space, of course, are very different from Earth. There is no gravity, sunlight, or atmosphere. High levels of ionizing radiation stunt plant growth. Plus, plants take up a lot of space, something that is, ironically, at a premium up there. These and special nutritional requirements of spacefarers have given scientists some specific and challenging problems.
To study fresh food production systems, NASA runs the Vegetable Production System (Veggie) on the ISS. Deployed in 2014, Veggie has been growing salad-type plants on “plant pillows” filled with growth media, including a special clay and controlled-release fertilizer, and a passive wicking watering system. They have had some success growing leafy greens and even flowers.
"Ideally, we would like a system which has zero waste and, therefore, needs zero input, zero additional resources."
A larger farming facility run by NASA on the ISS is the Advanced Plant Habitat to study how plants grow in space. This fully-automated, closed-loop system has an environmentally controlled growth chamber and is equipped with sensors that relay real-time information about temperature, oxygen content, and moisture levels back to the ground team at Kennedy Space Center in Florida. In December 2020, the ISS crew feasted on radishes grown in the APH.
“But salad doesn’t give you any calories,” says Erik Seedhouse, a researcher at the Applied Aviation Sciences Department at Embry-Riddle Aeronautical University in Florida. “It gives you some minerals, but it doesn’t give you a lot of carbohydrates.” Seedhouse also noted in his 2020 book Life Support Systems for Humans in Space: “Integrating the growing of plants into a life support system is a fiendishly difficult enterprise.” As a case point, he referred to the ESA’s Micro-Ecological Life Support System Alternative (MELiSSA) program that has been running since 1989 to integrate growing of plants in a closed life support system such as a spacecraft.
Paille, one of the scientists running MELiSSA, says that the system aims to recycle the metabolic waste produced by crew members back into the metabolic resources required by them: “The aim is…to come [up with] a closed, sustainable system which does not [need] any logistics resupply.” MELiSSA uses microorganisms to process human excretions in order to harvest carbon dioxide and nitrate to grow plants. “Ideally, we would like a system which has zero waste and, therefore, needs zero input, zero additional resources,” Paille adds.
Microorganisms play a big role as “fuel” in food production in extreme places, including in space. Last year, researchers discovered Methylobacterium strains on the ISS, including some never-seen-before species. Kasthuri Venkateswaran of NASA’s Jet Propulsion Laboratory, one of the researchers involved in the study, says, “[The] isolation of novel microbes that help to promote the plant growth under stressful conditions is very essential… Certain bacteria can decompose complex matter into a simple nutrient [that] the plants can absorb.” These microbes, which have already adapted to space conditions—such as the absence of gravity and increased radiation—boost various plant growth processes and help withstand the harsh physical environment.
MELiSSA, says Paille, has demonstrated that it is possible to grow plants in space. “This is important information because…we didn’t know whether the space environment was affecting the biological cycle of the plant…[and of] cyanobacteria.” With the scientific and engineering aspects of a closed, self-sustaining life support system becoming clearer, she says, the next stage is to find out if it works in space. They plan to run tests recycling human urine into useful components, including those that promote plant growth.
The MELiSSA pilot plant uses rats currently, and needs to be translated for human subjects for further studies. “Demonstrating the process and well-being of a rat in terms of providing water, sufficient oxygen, and recycling sufficient carbon dioxide, in a non-stressful manner, is one thing,” Paille says, “but then, having a human in the loop [means] you also need to integrate user interfaces from the operational point of view.”
Growing food in space comes with an additional caveat that underscores its high stakes. Barbara Demmig-Adams from the Department of Ecology and Evolutionary Biology at the University of Colorado Boulder explains, “There are conditions that actually will hurt your health more than just living here on earth. And so the need for nutritious food and micronutrients is even greater for an astronaut than for [you and] me.”
Demmig-Adams, who has worked on increasing the nutritional quality of plants for long-duration spaceflight missions, also adds that there is no need to reinvent the wheel. Her work has focused on duckweed, a rather unappealingly named aquatic plant. “It is 100 percent edible, grows very fast, it’s very small, and like some other floating aquatic plants, also produces a lot of protein,” she says. “And here on Earth, studies have shown that the amount of protein you get from the same area of these floating aquatic plants is 20 times higher compared to soybeans.”
Aquatic plants also tend to grow well in microgravity: “Plants that float on water, they don’t respond to gravity, they just hug the water film… They don’t need to know what’s up and what’s down.” On top of that, she adds, “They also produce higher concentrations of really important micronutrients, antioxidants that humans need, especially under space radiation.” In fact, duckweed, when subjected to high amounts of radiation, makes nutrients called carotenoids that are crucial for fighting radiation damage. “We’ve looked at dozens and dozens of plants, and the duckweed makes more of this radiation fighter…than anything I’ve seen before.”
Despite all the scientific advances and promising leads, no one really knows what the conditions so far out in space will be and what new challenges they will bring. As Paille says, “There are known unknowns and unknown unknowns.”
One definite “known” for astronauts is that growing their food is the ideal scenario for space travel in the long term since “[taking] all your food along with you, for best part of two years, that’s a lot of space and a lot of weight,” as Seedhouse says. That said, once they land on Mars, they’d have to think about what to eat all over again. “Then you probably want to start building a greenhouse and growing food there [as well],” he adds.
And that is a whole different challenge altogether.