This word let a severely brain injured patient tell neuroscientists she was still conscious using only her thoughts.
This word allowed a few covertly conscious brain injured patients to communicate for the first time.
This word could do more harm than good for these patients if we aren’t careful.
In 2006, one of us (A.M.O.) and colleagues at Cambridge University published a landmark study describing how functional magnetic resonance imaging (MRI) could be used to uncover consciousness in a patient in a so-called persistent vegetative state. Such patients show no evidence of awareness of themselves or their environment, and cannot move or speak.
Yet the team demonstrated that this patient could understand spoken commands — and respond to them — by modulating her brain activity. After being placed in an MRI scanner, the patient was asked to imagine playing tennis when she heard the words “imagine playing tennis,” and to rest each time she heard “now just relax.” During each imagery period, functional MRI detected activity in specific brain areas — the same ones that became activated in healthy individuals responding to the same instruction — that then ceased when she was asked to relax. These results provided compelling evidence that the patient was, despite all outward appearances, still conscious.
Subsequent studies have determined that as many as 15% to 20% of patients who have been rigorously diagnosed as being in a persistent vegetative state — now often referred to as unresponsive wakefulness syndrome — are covertly conscious. Some investigators have even used functional MRI to communicate with patients in this state, with imagining playing tennis representing “yes” and imagining navigating through their house representing “no.” One patient at Western University in Canada was able to answer several questions including his name, location, the date, and that he enjoyed watching hockey on TV. Thankfully, he also answered that he was not in any pain.
There are somewhere between 5,000 and 42,000 adults with unresponsive wakefulness syndrome in the United States alone, meaning a significant number of patients might be covertly conscious and possibly capable of communication using neuroimaging. Once we know they are conscious, we can take steps to enhance their quality of life. In the future, these patients might also be able to use communication by neuroimaging to make decisions, including decisions about further treatment.
Over the last decade, several commentators have speculated that these patients might be suffering in this state, including a recent First Opinion claiming that covertly conscious patients were being subject to “a form of unwitting medical torture.”
The author of the article, bioethicist Jacob M. Appel, asks readers to imagine what it would be like if our working minds were trapped in nonfunctioning bodies, if we were “prisoners in our own brains.” We suspect most readers would be horrified by the thought.
But is this the right way to think about these patients? We think not.
In general, patients with unresponsive wakefulness syndrome weren’t perfectly healthy one minute and prisoners in their bodies the next. These are individuals who have suffered catastrophic brain injuries and, after weeks, months, or even years of treatment and gradual recovery, emerge into a very strange place to which we on the outside have little access. We now know that some of these patients are conscious. But we really don’t know what their mental lives are like.
There is some evidence that these patients may not be faring as poorly as we might assume. Consider a different patient group: those in the locked-in state. They are incapable of voluntary movement — except vertical eye movement — or verbal communication, but remain cognitively intact. In one study, 72% of locked-in patients surveyed reported that they were happy. Another study used functional near-infrared spectroscopy to communicate with a patient completely paralyzed by Guillain-Barré syndrome, who reported that he felt safe.
Of course, this evidence doesn’t prove that patients with covert consciousness are happy, or even that they aren’t suffering. What it does show, however, is show that we may overestimate how badly off patients in severely disabled states are.
People tend to be poor at making judgements about the well-being of others, or their own well-being in the future. Most focus too heavily on a few pieces of information, usually whatever is presented to us first. Armchair speculation, however well-intentioned, is not a useful way forward here. What’s needed is creative collaboration between neuroscientists, clinicians, bioethicists, families, and caregivers to better understand the inner lives of these individuals.
We continue to be concerned about the possibility that some patients might be conscious but unreachable. This was part of our motivation to develop easier alternatives for detecting consciousness to help identify patients we might be missing. For example, some behaviorally non-responsive patients show remarkably similar patterns of brain activation as healthy controls when shown suspenseful movies that naturally engage attention. Research is also ongoing into other less expensive and more portable imaging modalities than functional MRI, including electroencephalography and functional near-infrared spectroscopy.
We believe that functional neuroimaging should be incorporated into standard diagnostic practice after severe brain injury, a fact recognized by the American Academy of Neurology in its most recent practice guidelines. The continued development of brain-computer interfaces could also open new avenues of communication, which may restore a degree of autonomy to patients with covert consciousness and provide further insights into their experiences.
In the meantime, rather than speculate, it is essential to use the accumulated evidence about the cognitive capacities of brain-injured patients to make careful inferences about their inner lives. Do they experience pleasure or enjoyment, and if so, how can these experiences be promoted? And how can the ways they might suffer be addressed?
We have thought long and hard about how we could ask patients about their quality of life, given the challenges of communication. Our recently developed quality of life measure may shed light on these questions. The possibility that some patients may be suffering worries us. But so does the possibility of withdrawing care from someone whose life is worth living. These decisions mustn’t be made guided by hunches.
Finally, it is of utmost importance to continue engaging with patients’ families and caregivers. Not only might they provide insights into patients’ behaviors and experiences, but they often have the largest impact on patients’ well-being. They need support.
By using their imaginations, a portion of patients with unresponsive wakefulness syndrome can show that they are still conscious. But we must do more than just imagine what their lives are like.
Mackenzie Graham is a senior research fellow in ethics at the Wellcome Centre for Ethics and Humanities, University of Oxford. Adrian M. Owen is professor of cognitive neuroscience and imaging at the Brain and Mind Institute at Western University. Charles Weijer is professor of philosophy, medicine, and epidemiology and biostatistics at the Rotman Institute of Philosophy at Western University.