In February I wrote about an article reporting that patients in a vegetative state may not be as unaware of their surroundings as doctors had previously thought (see News the Public Needs to Know). Now, I know that I’ve said I’ll try to be better in reading my books and magazines, but I just recently read the December 2009 issue of Scientific American. In it, there’s a short article about how some people can still learn while in a vegetative state.
A team of doctors at the Integrative Neuroscience Laboratory at the University of Buenos Aires has started developing tests to determine if patients have the ability to learn. The director of the lab, Mariano Sigman, said, “We want to have an objective way of knowing whether the other person [the patient] has consciousness or not.” The desire to find this objective method… (click here to read the entire article)
…stems in part from surprising neuroimaging work that showed that some vegetative patients, when asked to imagine performing physical tasks such as playing tennis, still had activity in premotor areas of their brains. In others, verbal cues sparked language sectors. …
To explore possible tests of consciousness in patients, Sigman and his colleagues turned to classical conditioning: they sounded a tone and then sent a light puff of air to the patient’s eye. The air puff would cause a patient to blink or flinch the eye, but after repeated trials over half an hour, many patients would begin to anticipate the puff, blinking an eye after only hearing the tone.
If two stimuli are delivered at exactly the same time, even snails will equate the stimuli. But the team actually delayed the puff after the tone by 500 milliseconds. To associate two stimuli separated by that time gap, “you need conscious processing,” says lead study author Tristan Bekinschtein of the Impaired Consciousness Research Group at the University of Cambridge. In fact, delaying the second stimulus by more than 200 milliseconds is enough to demonstrate some learning, he adds. By comparison, people under general anesthesia, considered to be entirely lacking awareness, showed no sign of such learning when given the tone and air-puff test.
…The detection of learning…also opens up questions about when patients should be classified as being in a persistent vegetative state, in which emergence isn’t predicted to be likely.
Why is this an important advance in diagnosing a patient’s condition? The article also states that: “A recent study found that about 40 percent of vegetative state diagnoses are incorrect” [emphasis mine].
In March, another news item on this topic showed up on the Scientific American website. It seems that certain patients in a “minimally conscious state” or a “vegetative state” due to brain injuries may be revived by injecting the patient with apomorphine, a drug used for patients with Parkinson’s disease.
Esteban Fridman of the FLENI hospital in Buenos Aires is one of the leading proponents in of this treatment. This excerpt tells a little bit about the theory and the research to this point (click here to read the entire news item):
Fridman hypothesizes that apomorphine might work by acting in place of dopamine. Flooding the injured brain with the chemical might stimulate it enough to repair the connections, enabling the patients to reach full consciousness. He notes the drug wouldn’t work in cases where the brain has been deprived of oxygen or blood, because the damage is more widespread. Terri Schiavo, a Florida woman whose care sparked a nationwide controversy that peaked in 2005, was in a vegetative state caused by that kind of injury.
…Fridman first tried apomorphine on a patient in 2004. The man had been in a minimally conscious state for 104 days. After he was given the drug the patient’s mother called Fridman to tell him her son had awakened after only 24 hours.
Over the next few years, Fridman and a colleague, Ben Zion Krimchansky at the Loewenstein Hospital Rehabilitation Center in Israel tried the drug on a total of eight patients. Seven recovered consciousness. (One subsequently died of an unrelated problem.) One welcome effect, Fridman says, was that patients did not regress even after the treatment was discontinued. Five improved to where they could walk, and one can now drive by himself.
…But because these clinical observations were not double-blind studies—in which neither the physicians nor the patients know if subjects get a placebo or the drug—Fridman currently is starting a formal clinical study with a total of 76 patients. The apomorphine will be given between one and four months after a traumatic brain injury, and the dosages will be spread over several weeks, given over 12-hour periods. Some patients will get the drug and some will be controls.
Maybe now that science has raised doubts about the realities of “vegetative state,” doctors and health-care professionals will be a little less quick to judge whose life is worth saving and whose is not. Maybe we’ll start honoring all people as human beings deserving of love and care, whether we think they can see us or hear us, or react the way we expect them. And when talking about Terri Schiavo and others in her condition, maybe we shouldn’t be so quick say, “I wouldn’t want to live like that.”
Because maybe, just maybe, that patient in a “vegetative state” can hear every word you’re speaking and is scared to death of what’s going on and that no one will hear her silent cries.