Study: Vegetative brains show some signs of awareness

February 4, 2010 at 12:00a.m.

NEW YORK (AP) — Scientists have detected glimmers of awareness in some vegetative brain- injury patients and even have 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.