This article was reprinted in our local paper earlier this week. I was surprised to find that there are possibly 10-15,000 people living in a persistant vegetative state in the US. I found this to be very interesting. Be sure to read the last two paragraphs about possibility of recovery. That was one of the issues surrounding Terri S case.
Published: Apr 5, 2005
Modified: Apr 5, 2005 3:10 AM
Brain injuries leave varied kinds of awareness
Researchers study unconscious states
By BENEDICT CAREY, The New York Times
The debate over Terri Schiavo's fate comes at a time when researchers are deepening their understanding of the unconscious brain. Neuroscientists understand at least some of the physiology behind a range of unconscious states, from deep sleep to coma, from partially conscious conditions to a persistent vegetative state, the condition diagnosed in Schiavo.
New research, by laboratories in New York and Europe, has allowed for clearer distinctions to be made between the uncounted number of people who at some time become comatose, the 10,000 to 15,000 Americans who subsist in vegetative states and the 100,000 or more who exist in states of partial consciousness.
This emerging picture should make it easier to judge which brain-damaged patients have some hope of recovering awareness, experts say, and it is providing clues to the specific brain processes that sustain conscious awareness.
"Understanding what these processes are will give us a better sense of how to help the whole range of people living with brain injuries," said Dr. Nicholas Schiff, an assistant professor of neurology and neuroscience at New York-Presbyterian/Weill Cornell hospital. "That is where this field is ultimately headed: toward a better understanding of what consciousness is."
The most familiar unconscious state is sleep, which in its deepest phases is characterized by little electrical activity in the brain and almost complete unresponsiveness. Coma, the most widely known state of impaired unconsciousness, is in fact a continuum. Doctors rate the extent to which a comatose person shows pain responses and reactions to verbal sounds on a scale from 3, for no response, to 13, for consistent responses.
As in sleep, people in comas may move or make sounds and typically have no memory of either. But they almost always emerge from this state in two to three weeks, doctors say, when the eyes open spontaneously. What follows is critical for the person's recovery.
Those who are lucky, or who have less severe injuries, gradually awaken. "The first thing I remember was telling my ex-boyfriend, who was at the foot of the bed, to shut up," said Trisha Meili, who fell into a coma after being beaten and raped in 1990, and wrote about the experience in the book, "I Am the Central Park Jogger."
In the days after this memory, Meili said, she slipped in and out of conscious awareness, "as if my body was taking care of the most important things first, and leaving my moment to moment awareness for last."
In fact, researchers say, this is precisely what happens. The primitive brain stem, which controls sleep-wake cycles as well as reflexes, asserts itself first, as the eyes open. Ideally, areas of the cerebral cortex, the seat of conscious thought, soon follow, like lights flicking on in the upper rooms of a darkened house.
But in some cases -- Schiavo's was one of them -- the cortical areas fail to engage, and the patient's prognosis becomes dire.
Neurologists were all but unanimous in diagnosing the condition of Schiavo, whose heart stopped temporarily in 1990, depriving her brain of oxygen. People with this kind of injury almost always remain unresponsive if they have not regained awareness in the first months after the injury. In medical terms, they become persistently vegetative.
In a review of the medical histories of 700 persistently vegetative patients, a team of doctors in 1994 reported that about 15 percent of those who suffered brain damage from oxygen deprivation, like Schiavo, recovered some awareness within three months. After that, very few recovered, and none did so after two years.
About 52 percent of people with traumatic wounds to the head, often from car accidents, recovered some awareness in the first year; very few recovered after that.
