Look at someone’s face and you might get an idea of what they’re thinking — if they’re sad, in pain, or feeling unwell. But when a patient is unable to move any part of their body purposefully — as in the case with those in a coma, a minimally conscious, or vegetative state — things become more difficult. Which is why Dr. Adrien Owen’s pioneering research into monitoring brainwave patterns in these types of patients is so important. He and his team at the Brain and Mind Institute at the University of Western Ontario have found a way for some patients to communicate without having to talk, lift a finger or even bat an eyelid.
Brain World: Can you explain the difference between various immobile states?
Adrian Owen: Right now there are three basic categories: vegetative, coma, and minimally conscious. People often confuse vegetative state with being in a coma, but it’s quite different. Patients in a vegetative state may open their eyes, have sleep and wakeful cycles. They may “wake up” and look around the room, leading to onlookers believing they can see as you or I see. But their eyes don’t fixate on anything, they look around in a non-purposeful manner. They don’t respond to people to moving objects, to music. These people are detached from the outside world but are nonetheless animate.
Coma is often the first stage after severe brain injury. In a coma, a person looks as though they are asleep — their eyes are closed, they move very little. And minimally conscious is a term that defines a kind of halfway state — a person may be able to respond to some extent, but it’s not clear. For example, they may be able to move their hand, but not enough to be able to communicate. This is the gray area between being severely disabled and in a vegetative state. And it’s here in this gray area that we’re working.
BW: So what abilities define these various states?
AO: The categories we have — vegetative, minimally conscious, and coma — are really a matter of convenience. They allow us to put a label on a person’s physical state, but in reality there are patients who are borderline or others who fluctuate between one state and another. We’re working towards a complete spectrum, where the patient’s abilities are described as they are, rather than us trying to make a label fit. So, for example, instead of a category, we’d say, “This patient can process visual information but not auditory; they can hear speech but they can’t understand,” and so on. That way, anyone treating that patient knows what the patient can and can’t do rather than simply knowing they are “minimally conscious,” which, realistically, is rather meaningless when treating an individual patient.
BW: So which kind of patients are you working with?
AO: Some patients, such as Jean-Dominique Bauby, who many people know of — he is the author of “The Diving Bell and the Butterfly” — for example, are able to move only one part of their body. Bauby was able to blink only one eyelid but as a result could communicate relatively effectively. This is called “locked-in syndrome” — the patient is completely conscious but unable to move effectively.
To test a patient like this, a doctor may ask him or her to squeeze his right hand, for example. If the patient consistently fails to respond, they may be classed as vegetative. Our patients are “locked-in patients plus”. They’re totally locked in. They don’t have the locked-in syndrome — they can’t move their eyes or some other body part to communicate. Our patients can’t move any body part purposefully.
BW: So how do your patients communicate without moving?
AO: We put an EEG system on these patients and ask them the standard question — squeeze your right hand, say — but rather than looking at their hand, we view the EEG. If we can see a spike in the premotor cortex — the part of the brain that would usually show activity when a person squeezes their hand — we know the patient can understand the question and is generating a response, even if it’s not physical. The response simply isn’t getting down from the brain to the body, so the hand doesn’t move. We’ve now perfected this technique using MRI scans. While functional MRI measures the magnetic fields produced by brain activity and EEG measures the electrical activity caused by these same changes, both are just different ways of measuring how a person’s brain is responding under different conditions.
BW: And how does this help the patient communicate?
AO: We asked one patient, who appeared to be vegetative, to imagine two scenarios for yes and no. The scenarios we use are being at home, visualizing what’s in the home for no, and playing tennis for yes. These have proven to be the most effective. The two scenarios show activity in different parts of the brain — thinking about tennis produces activity in the part of the brain related to motor activity; thinking about being at home, visualizing what’s in the home, produces activity in the part of the brain governing spatial awareness. That way, we can interpret when a patient is saying yes and when they are saying no. With one patient, for example, we asked questions about his life, to assess whether he was genuinely communicating. Of course, the questions were phrased in such a way that the patient only had to respond with yes or no.
For example, we’d ask, “Have you ever been to the USA?” or “Do you have any brothers?” or “Is your father’s name Alexander?” The patient managed to tell us where he’d been on holiday five years earlier and the name of his father — we verified everything with the family later.
BW: And what has your research revealed?
AO: We’ve discovered that nearly 20 percent of patients who are classified as being in a vegetative state, they are unresponsive in every way, are actually able to respond to questions. This shows they can hear and absorb information, and process that information to the point of formulating an answer, and communicating it.
BW: How do patients’ families and friends respond to the news?
AO: We’ve spent a lot of time with the patients’ families, and we ask them what they hope to get out of the procedure. Mostly they have come to terms with the idea that the patient isn’t going to recover, but they want to know if he or she is suffering, whether the patient can hear them when they recount family news, for example, or whether the patient can see a new visitor. And, amazingly, in 20 percent of cases we can give them an answer — yes, they can.
Usually it’s taken as good news. It might sound like a nightmare scenario to us, but in most cases we’re just confirming what the patient’s close family or friends suspected anyway. Most people who’ve sat by a patient for many years have a sense that there’s still some awareness, even though they have no evidence to prove it. People say, “He always knew when I was here,” and while I haven’t proved that this sense is generally accurate, it seems that often our findings validate suspicions that people already had.
The main thing families and friends want to know is what is going on. Can he hear me? Is she able to see her new nephew? These are the answers people want and, amazingly, in nearly 20 percent of cases, we can actually give them an answer.
BW: What value is your research for doctors?
AO: For families to know their loved ones can see or hear, for example, is emotionally important, but for doctors it’s about the patient’s overall well-being. Being able to ask basic yes/no questions to a patient could mean the difference between lying there immobile and in excruciating pain, and being given painkillers.
BW: So do your findings indicate some kind of error was made?
AO: No, although it might seem as though our research shows that some sort of misdiagnosis occurred, that’s not what’s happening. Some of the patients we’ve worked with appear to be entirely vegetative. They are completely locked into their bodies. We haven’t shown that not to be true — even after the patient has shown they are able to communicate via the brain scans or EEG, they remain locked into their bodies. So the doctor’s original diagnosis is as correct as it can be — we are simply able to produce new information that allows us to see abilities where no one could before.
And we can’t say with 100 percent certainty that the other 80 percent of patients we see are totally unconscious — it could be that they are unable to control that part of the brain relating to movement but can absorb information. Or it could be that the patient is deaf. How would we know that? There are so many reasons why a patient might fail our test that have nothing to do with whether they’re conscious or not. That’s why we don’t draw negative conclusions. We can only work with the information we’ve got, obviously, but that’s why with some patients it really isn’t a case of misdiagnosis, merely diagnosis based on the information you have.
BW: How soon will doctors be able to use this in hospitals nationwide or worldwide?
AO: One of the important things for us is to try and develop more simple ways to do this. MRI is very expensive. You have to bring a patient to the scanner, which means potentially transporting them over a long distance. EEG, however, is portable, so [it] can be taken to the patient. But it’s not a standard EEG — ours costs around $111,000, and it requires someone who’s got several years of experience to work on it. We’d like to do more research to develop a way that it can be used routinely, to be available to more people.
It’s a terribly exciting time. We’re getting closer to being able to make these tools widely clinically available, but it would also be wonderful to develop an apparatus people could take home to communicate with their loved ones. That’s what we’re working towards.