The field of coma and consciousness has produced some eye-opening stories in the past few years, most remarkably the case of Terry Wallis, a severely brain-damaged patient who regained the ability to talk. The new findings in this area have led to new ethical questions. Among them: Could doctors be erring in some cases, diagnosing as vegetative patients who are actually minimally conscious—and whose prognosis thus is better? Can people in vegetative or minimally conscious states feel pain, and should they be treated with painkillers?
Steven Laureys of the University of Liege addressed these questions on Monday during the David Kopf Lecture on Neuroethics at the Society for Neuroscience annual meeting. His lecture was called “Eyes Wide Open, Brain Wide Shut? (Un)consciousness in the vegetative state.”
Regarding diagnosis, Laureys cited a study in which 45 of 103 “post-comatose” patients were clinically diagnosed as vegetative. However, diagnosis using the Coma Recovery Scale showed that only 27 of those patients actually belonged in the “vegetative” category, a misdiagnosis of a vegetative state in 40 percent of these cases. Laureys said clinicians should take the time to carefully assess clinical signs of consciousness and not stop their search for signs of it prematurely.
Insight from brain imaging was a recurring theme in Laureys’ lecture. After noting that different levels of consciousness correspond with levels of overall brain activity, Laureys described how functional magnetic resonance imaging (fMRI) can measure activity in a brain at rest—thus providing a gauge by which to test activity in patients in various comatose states and help with diagnosis.
Imaging also can shed light on a patient’s prognosis. “New technologies, especially MRI … will really revolutionize [how] we can predict recovery,” Laureys said. He cited a study in which two of seven patients in a vegetative state showed “high-level” cortical activation. Three months later, only those two had recovered other signs of consciousness.
Clinicians might also adjust treatment based on imaging findings, Laureys said. For example, imaging studies suggest that patients in a vegetative state do not sense pain. But minimally conscious patients show greater brain activity in response to pain, including in an area important in the emotional perception of pain.
“In our view, this should lead to the systematic use of pain-killers and analgesia in patients in a minimally conscious state,” he said.
Laureys concluded by addressing ethical challenges directly, including the need for an overall ethical framework for how physicians deal with impaired consciousness following injury. Such a framework could take into account the quality of life of people living with locked-in syndrome (which is higher than we might expect, surveys indicate) and, as has arisen in Europe, end-of-life decisions such as organ donation from a patient with limited consciousness who sought physician-assisted death.
--Dan Gordon
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