A quarter of coma patients still retain some type of consciousness | Health & Wellness

Neuroscientist Ignacio Morgado says that many years ago he met a boy of about 25 who had been in a motorcycle accident. “He was sitting, eating, drinking, urinating, sleeping, and waking up, but he didn’t communicate with anyone,” he explains. “I was never sure whether this guy was conscious but couldn’t tell, or whether he was unconscious,” he recalls. This young man’s problem was similar to that of many others who, after an illness or an accident, are left bedridden, in a vegetative state, sometimes with their eyes open and occasionally moving, but unable to make a gesture of acknowledgement that they are listening when someone speaks to them.

An international team of scientists has just published a study involving 241 patients in various hospitals and has concluded that one in four is in some degree of consciousness. The work, published in The New England Journal of Medicineis an attempt to answer a painful question for people who lose a loved one, but not entirely: Are you listening to me when I talk to you? Does he know we’re here? These people sometimes regain consciousness, but in many cases they can remain in a coma for years or even decades. “The families are faced with a very troubling question: Should they turn it off?” Morgado says.

Across six study centers, researchers measured the brain activity of patients who were apparently oblivious to their surroundings when they were asked to imagine doing something, such as playing tennis. About one in four of them produced brain signals similar to those generated by healthy people when asked the same question and in the same areas of the brain, interpreted as a sign that they retained some degree of consciousness.

This isn’t the first time such a study has been conducted. Adrian Owen, one of the authors, writing in a note from the University of Western Ontario, where he now works, says that brain activity in some vegetative patients began to be seen in the mid-1990s, when he had his own lab in Cambridge, UK. “We would show them pictures and play recordings of people talking, and bits of their brains would light up, but we didn’t know what it meant,” he says. “Then I had this moment.” Eureka and I realized that I needed to get someone to do something that couldn’t be an automatic reflex,” he continues. In addition, this type of order illuminated two unique parts of the brain during fMRI in both healthy and vegetative patients. They published their results in a journal article. Science in 2007.

Since then, many researchers have found similar results by adding brain signal measurements such as electroencephalograms, although the percentage of patients who showed some consciousness was somewhat lower than that found in the last paper. In the study that has just been published, we wanted to get more convincing results by including more patients, including those who had already participated in previous studies, and in several centers at the same time.

“Until recently, we thought it was 15% to 20% of patients, maybe more, but the specifics are not that important, it’s more of a significant percentage of patients that need to be taken into account,” he says. Davinia Fernandez-Espejo of the University of Birmingham, who studies problems with consciousness caused by brain injury. Fernandez-Espejo says that for it to be routinely used in hospitals, one of the steps needed is “standardising the tests, the measurements and the analyses, so that whether you’re doing the test here or in the US or in this or that hospital”. We’ll then try to use that information to improve treatment for patients. “We’re working with a private hospital in London to develop brain stimulation techniques to rehabilitate patients who we see as conscious, and we’re trying to target the motor pathways and see if we can help them regain some control of movement,” he explains.

His team has come up with an explanation for why these apparently conscious people can’t communicate with the outside world. “We’ve found fibers that connect a region of the brain called the thalamus, inside the brain, to parts of the cerebral cortex that regulate movement,” he says. This disconnect, which they only see in patients who are conscious but unable to move voluntarily, although they can move spontaneously, has them thinking about a possible therapy. “We want to activate a few neurons that need to connect these two areas with electrical stimulation to restore the patient’s mobility,” he says.

The ability to better understand the characteristics of these people who are conscious but unable to communicate suggests the possibility of using brain implants similar to those that have helped completely isolated people with amyotrophic lateral sclerosis regain some level of communication. Nicholas Schiff, a co-author of the study, believes that some of these patients could benefit from this type of implant.

However, although the tasks used in studies such as the one published in The New England Journal of Medicine indicate that attention, language comprehension and memory capacity may be very well preserved in a quarter of patients in a vegetative state, this is just a snapshot of the moment at which the experiment is conducted, and the diversity of abilities among patients in a vegetative state is great. “During the rest of the day there may be fluctuations, sometimes they are more or less alert, and in fact, this is what we usually see in these patients,” explains Fernandez-Espejo. “It is difficult to develop methods to know your inner experience, for example, to conduct a psychological study,” he adds.

One of the dilemmas for patients with such brain injuries is whether to give them a choice about whether to continue living or not. A researcher at the University of Birmingham explains that at the moment “we are limited to asking yes or no questions that take five minutes to answer”. “In theory it can be done, but it is very difficult, and at the moment we are concentrating on questions that can help us improve their quality of life,” he says.

While news that some people in a vegetative state are conscious may be exciting for their family or friends, it does not mean they will recover or that treatment can be used to achieve that goal. What goes on in the minds of others, even if they can express themselves, is a mystery far from solved. Still, the knowledge can be helpful. Owen believed that it would be worse for a patient’s loved ones to learn that they are conscious but trapped inside than to learn that they do not know who they are or what their situation is. “That’s not the general case,” he explains, “typically the opposite.” They almost always like to know that the person they thought was lost is still there, even if they cannot contact them.

You can follow EL PAIS Health and Wellbeing V Facebook, X And Instagram.