fMRI May Allow Communication With Some Patients in Vegetative or Minimally Conscious States

Susan Jeffrey

February 04, 2010

February 4, 2010 — Researchers are reporting evidence of willful brain activation in a small number of patients in vegetative or minimally conscious states using functional magnetic resonance imaging (fMRI). Further, 1 patient with a diagnosis of vegetative state was able to correctly answer yes or no questions by activating different areas of his brain through visualization of different activities while he was undergoing fMRI, this despite being unable to show any signs of consciousness at the bedside.

The lead author on the paper is Martin M. Monti, PhD, from the Medical Research Council (MRC) Cognition and Brain Sciences Unit and the Wolfson Brain Imaging Center at the University of Cambridge in the United Kingdom.

"Normally, for family and medical staff, the best practice is always to act with these patients as if they were conscious, because we never know," Dr. Monti told Medscape Neurology. "But, of course, here we have proof; we do know."

Still, he cautioned, their work is preliminary. "This is 1 patient. This does not tell us about whether other patients can communicate in this way or not."

In this series of 54 such patients, they have found 5 who can modulate their brain activity in this way and 4 with a diagnosis of vegetative state, all stemming from traumatic brain injuries. Their work was published online February 3 in the New England Journal of Medicine.

Willful Modulation of Brain Activity

This group, with coauthors that include Adrian M. Owen, PhD, also at the MRC Cognition and Brain Sciences Unit, and Steven Laureys, MD, PhD, at the University of Liege in Belgium, have previously reported exciting work using fMRI in brain injured patients.

In 2006, Dr. Owen and colleagues reported a single case of a woman who was in a vegetative state after a car crash in 2005 (Owen AM, et al. Science. 2006;313:1402). Five months after her car crash, the researchers scanned her brain using fMRI, asking her to visualize herself playing tennis, hitting a ball with an instructor, or navigating familiar streets of a city or the rooms of her home, standard tasks known to produce activation in specific areas of the brain.

"When we did this, we saw that she would activate during several tasks in a way that was indistinguishable from a normal, healthy, awake individual," Dr. Owen told Medscape Neurology at that time.

In 2007, they reported results from scanning 10 such patients and found among these 1 more patient who could produce willful brain activation in this way but no sign of activation in the others. Their findings indicated this type of patient is in the minority, they noted (Arch Neurol. 2007;64:1098-1102).

In the new paper, Dr. Monti and colleagues have now scanned 54 patients using fMRI, 23 with a diagnosis of vegetative state and 31 in a minimally conscious state. Among these, they found 5 patients who were able to modulate their brain activity. Four of these, including the patient described in 2006, had a diagnosis of vegetative state vs 1 considered in a minimally conscious state, and all had experienced traumatic brain injury.

When they retested these 5 patients using standard bedside clinical tests, some behavioral indicators of awareness could be detected in 2, but in the others, no such signs could be found.

"Even though they could never do anything to indicate consciousness in these tests at the bedside, in the fMRI machine they could unambiguously tell us that they were conscious," Dr. Monti said.

... in the fMRI machine they could unambiguously tell us that they were conscious.

Finally, the researchers assigned yes or no responses to these different areas of activation, "tennis" for the motor imagery task, and "navigation" for the task visualizing walking through familiar rooms.

In 1 patient, a 22-year-old man from Liege who responded reliably on these tasks, investigators asked 6 yes or no autobiographical questions and instructed him to respond by thinking of the task assigned to the yes or no answers.

He was able to respond in a factually correct way to 5 of the 6 questions; the answer to the last question was not incorrect, they note, but rather "virtually no activity was observed in the regions of interest."

Dr. Monti emphasized that it is not clear at this point how many patients may be able to respond in this way. Further, fMRI is a technically intensive technique that is not available at all hospitals and cannot be used on any patient who requires the presence of metal medical apparatus.

Still, if replicated, he concluded, this may be "an additional way to help us understand if a patient who doesn't give us any clear sign of consciousness when we test at the bedside is conscious or not."

"Descartes Before the Horse"

In an editorial accompanying the publication, Allan H. Ropper, MD, from the Department of Neurology at Brigham and Women's Hospital, Boston, Massachusetts, calls the work an "imaginative" series of experiments that "has revealed a form of preserved cognition in ostensibly unconscious patients."

However, he is cautious in his assessment of what this willful activation may mean.

"Research on clinically undetected consciousness is easily subject to overinterpretation and sensationalism that the authors certainly do not intend," Dr. Ropper writes. For physicians discussing these findings with families and wider society, 3 points should be borne in mind, he notes.

"First, in this study, brain activation was detected in very few patients. Second, activation was found only in some patients with traumatic brain injury, not in patients with global ischemia or anoxia," Dr. Ropper writes.

"Third, cortical activation does not provide evidence of an internal 'stream of thought' (William James' term), memory, self-awareness, reflection, synthesis of experience, symbolic representations or — just as important — anxiety, despair, or awareness of one's predicament. Without judging the quality of any person's inner life, we cannot be certain whether we are interacting with a sentient, much less a competent, person," he adds.

... physicians and society are not ready for 'I have brain activation, therefore I am.'

Further, anyone who would use this to justify continued life support for all unresponsive patients "is missing the focus of the findings."

"The mind is an emergent property of the brain and cannot be 'seen' in images," Dr. Ropper concludes. "The article by Monti et al is provocative; however, physicians and society are not ready for 'I have brain activation, therefore I am.' That would seriously put Descartes before the horse."

The study was supported by grants from the MRC; the European Commission (Disorders and Coherence of the Embodied Self, Mindbridge, Deployment of the Brain – Computer Interfaces for the Detection of Consciousness: A Transdisciplinary, Integrated Approach); Fonds de la Recherche Scientifique; the James S. McDonnell Foundation; the Mind Science Foundation; the Reine Elisabeth Medical Foundation; the Belgian French-Speaking Community Concerted Research Action; University Hospital of Liege, the University of Liege; and the National Institute for Health Research Biomedical Research Center (Neurosciences Theme). The study authors have disclosed no relevant financial relationships.

N Engl J Med. Published online February 3, 2010.


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