Brain Scan May Foster Communication With Vegetative Patients
A novel brain scan may foster communication with vegetative patients.
Feb. 3, 2010 -- For the brother of Terri Schiavo, Wednesday's news that a team of researchers in England were able to use a novel scanning technology to establish limited communication with a man in a persistent vegetative state was bittersweet.
Bobby Schindler said that while the test using functional magnetic resonance imaging (fMRI) likely holds promise for the families of minimally conscious and persistently vegetative patients, he wishes his sister had been afforded this technology before a court ruling allowed her husband Michael Schiavo to remove her feeding tube in 2005 leading to her death.
"It's upsetting to me when I see this type of research," Schindler said. "We were looking to afford these kinds of tests for Terri, but the court did not allow us to perform these kinds of tests."
Schiavo's case ignited a firestorm of publicity in between 1998 and 2005. Ultimately, the courts sided with doctors who testified that Schiavo was in a persistent, vegetative state with no hope of recovery -- though doctors that the Schindlers brought to court said there was a chance of recovery.
The case eventually went to the U.S. Supreme Court, which refused to intervene.
The new study released Wednesday that could spell hope for many families likely will arouse a measure of controversy as well.
"I think it shows that if you just use the conventional bedside-type of exam [to determine consciousness], you can get it wrong," Schindler said.
In the new study, researchers found that a 34-year-old man was able to answer simple yes or no questions by imagining different types of activity, which caused changes in brain activity that could be seen in the machine, according to Martin Monti of the Medical Research Council Cognition and Brain Sciences Unit in Cambridge, England, and colleagues.
The finding showed that at least some patients who are otherwise unresponsive may have some residual awareness, the researchers reported online in the New England Journal of Medicine.
"The incredible thing is that we could never do something like that at the bedside," Monti told MedPage Today. Outside of the fMRI machine, he said, the patient remained unresponsive to standard tests.
Scan Evoked No Response From Most Patients
Monti, too, conceded that the study could spur controversy, particularly in light of cases like Schiavo's.
"People will have a tendency to over-interpret this," Monti said. "This finding in one patient does not imply that all patients may or may not have the ability to do this."
Indeed, the researchers tested 54 people and found only five who apparently could respond to direction by imagining either motor or spatial activity. Imagining those activities uses different parts of the brain and their activation can be seen by the fMRI scan.
Several of the responders were already in what is called a "minimally responsive" state, meaning that occasionally they were able to react to external stimuli.
Of those five, the researchers only tried to communicate with one -- the man in a persistent vegetative state -- using his ability to reliably activate different brain areas when asked to imagine either playing tennis or looking around a room in his house.
While in the machine, he was asked simple questions, such as whether his father's name was Alexander. To answer "yes," he was to imagine playing tennis, while for "no" he was to imagine looking around the room.
He was able to answer five out of six questions, the researchers reported, adding it was unclear why he was unable to answer the sixth but no brain activity was seen in response to the question.
Outside experts also cautioned against over-interpreting the results.
"The percentage of patients showing a response was low, and longer-term follow up studies are needed to determine whether such fMRI findings by themselves have meaningful predictive value," said Dr. Alan Faden, a neurologist at the University of Maryland School of Medicine in Baltimore. "Use of fMRI is not likely to become standard for evaluation of these subjects but rather probably will be used in selected patients in centers with research interests."
Dr. Steven Flanagan, medical director of the Rusk Institute of Rehabilitation Medicine at the New York University Langone Medical Center, said the legal implications of the study were "a mess," as the study still leaves some key questions about consciousness unanswered.
"It remains impossible to say to families that their loved [ones] are definitively not there; this study certainly supports that we cannot say this," he said. "However, less than 5 percent showed activation, and only those who sustained TBI [traumatic brain injury] had activation. No one with global ischemia or anoxic brain injury did."
Questions Remain on Minimally Conscious Communication
And then there is the quality of the awareness, Flanagan said.
"Presuming someone can imagine themselves playing tennis cannot be interpreted as awareness of their condition, prognosis, quality of life, et cetera."
Faden said that the technology may one day have even bigger implications for medical practice. Once it improves, it will likely mean that doctors will have to modify their diagnostic categories for what he called "states of diminished consciousness."
And in an accompanying editorial in the journal, Dr. Allan Ropper of Brigham and Women's Hospital in Boston wrote that such research is "easily subject to over-interpretation and sensationalism."
He cautioned that brain activation was seen only in a few patients and only in those with a traumatic brain injury, rather than global ischemia and anoxia.
Additionally, he wrote, the brain activity seen in the patients is not evidence of such things as memory, self-awareness, anxiety or despair.
"We cannot be certain whether we are interacting with a sentient, much less a competent, person" Ropper wrote.
Still, Dr. Gregory O'Shanick, president and medical director of the Center for Neurorehabilitation Services in Richmond, Va. and national medical director of the Brain Injury Association of America, said that for some patients, the method could offer even more promise. Specifically, for those 12 patients in the study whose vegetative states were caused solely by traumatic brain injury, the fMRI had a 33 percent "hit" rate in finding those who still exhibited responsive brain patterns.
"The use of this fMRI technology with that specific patient population found that one-third of these patients were misdiagnosed," O'Shanick said. "Sadly, in the setting of anoxia, meningitis or stroke, the message from this specific study is less compelling."
Research Raises Medical, Legal Questions
Despite such caveats, the research is "critically important," according to Dr. Michael DeGeorgia, director of the Neurocritical Care Unit at University Hospitals Case Medical Center in Cleveland.
It "illustrates both the complexities of this area and the limitations of our bedside clinical examination," he said in an e-mail, adding that more research will be needed to figure out how to use the technology and how to interpret the results.
The research "does raise difficult medical and legal questions," DeGeorgia said.
"We always need to be upfront and honest with families about what we know for certain and what we do not know for certain," he said. "In many of these cases, the honest answer is that we cannot be absolutely 100 percent certain that their loved one isn't 'in there somewhere.'"