A groundbreaking study, raising troubling medical ethics issues, has found that patients in a vegetative state showed signs of brain activity, indicating not only consciousness but even the ability to communicate.
The study, published online Wednesday by The New England Journal of Medicine, http://content.nejm.org/cgi/content/full/NEJMoa0905370, created an immediate debate about how serious head injuries should be treated, as well as the ethical issue of whether attempts should be made to ask comatose patients what kind of care they want.
In other words, should vegetative patients, once considered unresponsive, now be asked whether they want to live or die?
In the study, 54 patients with vegetative brain injury in England and Belgium were assessed with functional magnetic resonance imaging (MRI), to determine if they could respond to two established imagery tasks. And an additional technique was developed to determine “whether such tasks could be used to communicate yes-or-no answers to simple questions,” according to The New England Journal.
Five patients (five of whom were diagnosed with traumatic brain injury, and four diagnosed as being in a vegetative state) were “willfully able to modulate their brain activity,” the Journal said, “In three of these patients, additional bedside testing revealed some signs of awareness, but in the other two patients, no voluntary behavior could be detected by means of clinical assessment.”
Imaging tests involving one woman showed she had brain activity, in her motor cortex, when she was asked to think about playing tennis, the study found.
One patient was able to answer yes or no questions during the MRI, “however, it remained impossible to establish any form or communications at bedside,” according to the New England Journal article.
The study’s conclusion was that “these results show that a small proportion of patients in a vegetative or minimally conscious state have brain activation reflecting some awareness and cognition. Careful clinical examination will result in reclassification of the state of consciousness in some of these patients. This technique may be useful in establishing basic communication with patients who appear to be unresponsive.”
The study had two goals: The first was to determine whether patients in a vegetative or minimally conscious state retain the capacity for a purposeful response to stimulation, however inconsistent. “Such a capacity, which suggests at least partial awareness, distinguishes minimally conscious patients from those in a vegetative state and therefore has implications for subsequent care and rehabilitation, as well as for legal and ethical decision making,” the New England Journal article said.
The second goal of the study was “to harness and nurture any available response, through intervention, into a form of reproducible communication, however rudimentary. The acquisition of any interactive and functional verbal or nonverbal method of communication is an important milestone. Clinically, consistent and repeatable communication demarcates the upper boundary of a minimally conscious state.”
In introducing the study’s findings, the New England Journal said, “ In recent years, improvements in intensive care have led to an increase in the number of patients who survive severe brain injury. Although some of these patients go on to have a good recovery, others awaken from the acute comatose state but do not show any signs of awareness. If repeated examinations yield no evidence of a sustained, reproducible, purposeful, or voluntary behavioral response to visual, auditory, tactile, or noxious stimuli, a diagnosis of a vegetative state — or “wakefulness without awareness” — is made. Some patients remain in a vegetative state permanently. Others eventually show inconsistent but reproducible signs of awareness, including the ability to follow commands, but they remain unable to communicate interactively.”
That term “minimally conscious state” was used in 2002 by the Aspen Neurobehavioral Conference Work Group to describe the condition of these kinds of patients, “thereby adding a new clinical entity to the spectrum of disorders of consciousness,” the article says.
One of the five patients that showed brain activity, the study found “had the ability to apply the imagery technique in order to answer simple yes-or-no questions accurately. Before the scanning was performed, the patient had undergone repeated evaluations indicating that he was in a vegetative state…the functional MRI approach allowed the patient to establish functional and interactive communication.”
The article went on, “Indeed, for five of the six questions, the patient had a reliable neural response and was able to provide the correct answer with 100% accuracy. For the remaining question — the last question of the imaging session — the lack of activity within the regions of interest precluded any analysis of the results. Whether the patient fell asleep during this question, did not hear it, simply elected not to answer it, or lost consciousness cannot be determined. Although the functional MRI data provided clear evidence that the patient was aware and able to communicate, it is not known whether either ability was available during earlier evaluations.”
The study received wide coverage in the press, with a Page One story in The New York Times http://www.nytimes.com/2010/02/04/health/04brain.html?hp
and The Star-Ledger of Newark, which ran The Washington Post’s story on the surprising study results, http://www.washingtonpost.com/wp-dyn/content/article/2010/02/03/AR2010020302887.html.
The Wall Street Journal http://online.wsj.com/article/SB10001424052748704259304575043494009308442.html, Los Angeles Times
http://www.latimes.com/news/nationworld/nation/la-sci-vegetative4-2010feb04,0,4078396.story
and the Associated Press also did coverage of the study.
The New York Times wrote, “The experts agreed that the new study exposed the limits of the current bedside test for diagnosing mental state: checking whether patients’ eyes can track objects, and carefully looking for any signs – eye blinks, finger twitches – in response to questions or commands.”
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