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Thursday, February 04, 2010
Vegetative Brains Show Signs of Awareness
By Malcolm Ritter
AP Science Writer
NEW YORK — Scientists have detected glimmers of awareness in some vegetative brain-injury patients and have even communicated with one of them — findings that push the boundaries of how to assess and care for such people.
The new research suggests that standard tests may overlook patients who have some consciousness, and that someday some kind of communication may be possible.
In the strongest example, a 29-year-old patient was able to answer yes-or-no questions by visualizing specific scenes the doctors asked him to imagine. The two visualizations sparked different brain activity viewed through a scanning machine.
"We were stunned when this happened," said one study author, Martin Monti of Medical Research Council Cognitive and Brain Sciences Unit in Cambridge, England. "I find it literally amazing. This was a patient who was believed to be vegetative for five years."
Ever since a research paper four years ago showed apparent signs of awareness in a vegetative patient — one who was included in the new study — families of patients have been clamoring for brain scans, said Dr. James Bernat of Dartmouth Medical School, a spokesman for the American Academy of Neurology.
In fact, a spokeswoman for a patient advocacy group said the organization will urge families to ask about the type of brain imaging used by the researchers.
But experts said more study is needed before the specialized brain scans could be used routinely. "It's still a research tool," Bernat said.
Experts also emphasized that only a few tested patients showed evidence of awareness. And they said it is not clear what degree of consciousness and mental abilities the signs imply.
They also noted that the positive signals appeared only in people with traumatic brain injury — not in patients whose brains had been deprived of oxygen, as can happen when the heart stops. Terri Schiavo, the vegetative woman at the center of a national controversy before her feeding tube was removed and she was allowed to die in 2005, suffered oxygen deprivation.
The new work, published online Wednesday by the New England Journal of Medicine, came from researchers in Britain and Belgium. One author is Dr. Steven Laureys at the University of Liege in Belgium. He made headlines in November by showing awareness in Rom Houben, a 46-year-old man who had been diagnosed as being vegetative for 23 years. (Houben was excluded from the new study because he could not keep his head still enough in the brain scanner to produce a usable scan; his awareness was revealed by bedside behavioral tests).
The new study used brain scanning called functional MRI, or fMRI, for 23 patients in a vegetative state and 31 diagnosed as minimally conscious.
Patients are diagnosed as being in a vegetative state if they are tested and found unable to do such things as move on command or follow a moving object with their eyes. (Their eyes are open; in contrast, comatose people's eyes are closed.) Minimally conscious patients show signs of awareness, but they are minimal and intermittent.
While in the fMRI scanner, the patients were asked to imagine two situations. One was that they were standing on a tennis court, hitting a ball to an instructor; the other was that they were navigating familiar streets or walking from room to room in their homes. The two tasks produce different patterns of brain activity in healthy people.
The study found those patterns appeared in five patients when they were asked to imagine the scenes. Four of those patients had been diagnosed as vegetative.
"It just says how much we can learn from looking directly at somebody's brain," Monti said.
But he said the results cannot be taken to indicate how commonly a vegetative brain holds hidden signs of awareness. And the findings certainly don't mean all vegetative patients have that capacity, he said.
The 29-year-old, who had been injured in a traffic accident, was asked simple questions about his life, such as "Is your father's name Alexander?" He was told to answer "yes" or "no" by thinking about one or the other of the imagined scenes about playing tennis or navigating streets or his home. For five of the six questions, his brain activity matched the correct answer.
Monti and Laureys said it is not clear whether such patients have the mental capacity to answer more important but complicated questions, such as whether they wish to go on living.
"I'm trying to figure out what is the best way to tackle this," Laureys said.
Just about a year ago, one of the most photographed and chronicled wild big cats in the United States — a jaguar that roamed the Southwest — stepped into a metal trap a few miles north of the Mexican border in Arizona.
Macho B, as the jaguar was called, was snared, tranquilized, fixed with a radio collar and released. Twelve days later, when he was not moving and it was obvious something was wrong, he was captured again, examined and put to the death. He was somewhere between 16 and 20 years old.
The death of one old jaguar affected a lot of people in surprising ways.
Macho B was eulogized like a celebrity, and I guess he was one. People regularly report seeing jaguars in the Southwest — it happens every few years in New Mexico, although most of those reports are not confirmed — but Macho B had been spotted frequently and photographed as well. He was often called the last known jaguar living in the wild in the United States.
Jaguars are the largest cats in the Western Hemisphere, and there is something alluring about the prospect of having a 6-foot-long, 200-pound predator with jaws that can kill a deer in one snap walking unseen in the world in which we live.
I read everything I could about Macho B after he died and felt sad in a way that seemed out of proportion with the event, up until I realized what it meant — the end of an era in the Wild West and another symptom of a world that is out of balance.
But in the wake of the big cat's death, it seems that Macho B's legacy might be more positive than that.
Just last month, the U.S. Fish and Wildlife Service was ordered by a federal court to develop a recovery plan for wild jaguars in the United States and to designate a "critical habitat" area for the cat's well-being. It was the reversal of a long-standing refusal by the Bush administration to take efforts to protect the jaguar.
And just two weeks ago, the federal agency tasked with investigating complaints of government wrongdoing issued a stinging report about Macho B's trapping, collaring and ultimate death at the hands of Arizona game managers.
The Office of the Inspector General, urged on by two members of Congress, reviewed hundreds of e-mails and documents, along with 38 interviews conducted by U.S. Fish and Wildlife agents in a separate criminal investigation into the circumstances surrounding Macho B's death.
Its conclusion came in a redacted report that was light on details but clear in its conclusion: The capture of Macho B by the Arizona Game and Fish Department was intentional. There was evidence linking a subcontractor and possibly an employee to "criminal wrongdoing in the capture of Macho B."
Arizona Game and Fish disputes the Inspector General's conclusion and maintains no one associated with the department was directed to capture the jaguar.
The public story of the cat's death a year ago had been one of an unavoidable tragedy: unintentionally snared in a trap set by government wildlife managers for mountain lions and bears, the jaguar had been found to have failing kidneys and was put out of his misery.
The Inspector General's report outlines a tragedy of a different sort. It concludes that the team trapping in the Coronado National Forest knew Macho B was nearby and had none of the permits required to trap an animal with endangered species protection.
According to the report, three federal agents were assigned to the criminal case and it is currently being reviewed by an assistant U.S. attorney in Arizona. Arizona Game and Fish disputes it did not have proper permits and says it is cooperating fully with the federal investigation.
Once he was trapped, there is also the question of whether Macho B needed to die. He was caught in the foot trap on Feb. 18 and remained there overnight until he was shot with a tranquilizer dart, affixed with a radio collar and released. In the trapping, the report said, he had broken off a canine tooth down to the root.
He was captured again, taken to the Phoenix Zoo and examined. Veterinarians there attributed the cat's decline to kidney failure and the tooth injury. They decided he could not be saved and euthanized him. One of the veterinarians disagreed with the diagnosis, saying the cat did not suffer from significant kidney disease.
What's the difference if a jaguar that roamed around southern Arizona and New Mexico and northern Mexico dies a few years before his time? Does it even matter if he's truly the last one here?
It's more than a sentimental concern. Jaguars used to walk all over New Mexico and up into Colorado. There's evidence they were in northern New Mexico as recently as the 1930s. A confirmed sighting in southern New Mexico came as recently as four years ago.
Like the stealthy mountain lions that walk all around us, it is likely jaguars have watched humans much more often than humans have spied them.
Michael Robinson, who lives in the Gila Mountains and is a conservation advocate for the Center for Biological Diversity, has led the charge to protect the jaguar as well as to reintroduce the Mexican gray wolf in New Mexico. Jaguars evolved in North America and at one time stretched from California to the Carolinas.
"To think that the animal was finally reduced to Macho B here and then he's gone is frankly tragic," Robinson says. "Having the full suite of species, including jaguars, is a sign to our society that we have left some places intact."
It's not too far of a stretch to compare the wolf's situation to that of the jaguar. The difference between the wolf and the jaguar is that the jaguar has not been hunted away — yet. It doesn't need to be reintroduced, only protected by wildlife managers so the migration between Mexico and the American Southwest can continue .
And then? Let's leave them alone. That's a lesson we should have learned from Macho B.
UpFront is a daily front-page news and opinion column. You can reach Leslie at 823-3914 or llinthicum@abqjournal.com.
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