Technique May Help Revive Head-Injury Victims
Monday, October 16, 2006
Doctors yesterday reported the first evidence that targeted electrical brain stimulation may help head-trauma victims stuck in a state of semiconsciousness, after an experiment apparently restored some of one patient's abilities to function and communicate.
Although the technique has been tried on only one patient, the experiment marks an unprecedented step that could lead to a new way to try to coax thousands of patients mired in similar states back toward more awareness, enabling them to function more and interact better with their families and others.
"It sounds promising," said James L. Bernat, a neurologist at Dartmouth Medical School who was not involved in the research. "If it turns out to be helpful for other patients, then it certainly would be an important therapy."
Thousands of Americans are left unconscious or semiconscious by brain damage. Many go into a coma, in which they are alive but completely unconscious. Some eventually emerge into a vegetative state, in which their eyes open and close but they show no signs of conscious awareness or ability to interact with their environment. The most famous recent example of this was Terri Schiavo, whose case triggered a national debate over the right-to-die issue.
Other head-injury victims move into a related condition recently defined as a "minimally conscious state," in which they appear to intermittently have some awareness and ability to respond to stimuli, but their responsiveness is highly unpredictable and limited. Family members spend years at these patients' bedsides, hoping for signs of recognition or improvement, which occur very rarely.
Some researchers have been able to achieve some improvement in a few of these patients with drugs, including those used to treat Parkinson's disease, but their effectiveness has been very limited.
In the new approach, researchers at Cornell University's Weill Medical College in New York, the Cleveland Clinic in Ohio and the JFK Johnson Rehabilitation Institute in Edison, N.J., got Food and Drug Administration approval to try a technique known as deep-brain stimulation (DBS).
The technique, which has been shown to be effective for treating some patients with Parkinson's disease, severe pain, epilepsy, depression or obsessive-compulsive disorder, involves inserting tiny electrodes into the brain to stimulate specific regions.
Researchers have tried this technique on patients in vegetative states, including Schiavo, without success. The new experiment marks the first time it has been tried on a patient in a minimally conscious state.
In a presentation yesterday at a meeting of the Society for Neuroscience in Atlanta, the researchers said the case involved a 38-year-old man who had suffered a severe brain injury that left him in a minimally conscious state for six years, unable to communicate or function in any consistent way. Brain scans, however, showed that many parts of his brain were still working.
After an intensive four-month evaluation to assess his capabilities, surgeons at the Cleveland Clinic implanted electrodes into parts of his brain known as the thalamus, believed to be involved in helping integrate the functions of other areas.
For the first six weeks after the procedure, before any stimulation began, the man's condition did not improve.
For the next five months, the researchers calibrated how much to stimulate his brain. Then, during a six-month trial period, the activation was turned on and off without those evaluating him knowing when it was on and when it was off.
The results of that test found significant improvement in the man's abilities to move, communicate and function, including his abilities to eat and respond verbally. While the researchers refused to elaborate on his improvement until their findings are published in a scientific journal, they reported that even when the stimulation is off, the patient continues to demonstrate improved "gestural and verbal communication abilities," which suggests that the stimulation may be having lasting effects on his brain.
"These findings provide the first evidence that DBS can promote significant late functional recovery from severe traumatic brain injury," the researchers wrote in their presentation.
The findings could fundamentally alter the way such patients are treated, the researchers said.
"Our observations years after the injury occurred challenge the existing practice of early treatment discontinuation for patients with only inconsistent interactive behaviors and motivate further research to develop therapeutic interventions," they wrote.
Although the findings are promising, the researchers stressed that they needed to be confirmed by studying additional patients.
"We need to do this in more subjects," said Nicholas D. Schiff of Cornell, one of the researchers. "The next step is to go forward with the current trial and do another case. We need to see where this goes."
Bernat called the results "fascinating" and "provocative," but he cautioned that more work was needed to see whether the approach would help others.
"When you present one case in which something seems to be beneficial, it always raises the question of whether this is typical or unusual," he said. "When you have only one case you don't know. But this certainly is encouraging."
Bernat noted that the approach was "fairly invasive" but that "if it turns out this does help, it certainly would constitute justification."
The researchers made a second presentation outlining the intensive process they went through to vet the ethical questions raised by the test and protect the patient's interests, including getting permission from a surrogate and several internal and external review boards.
"We tried to conceive of every conceivable safeguard," said Joseph J. Fins, a Cornell bioethicist involved in the study.
Other ethicists agreed.
"At a glance it looks like they've taken all the right steps," said Kenneth Goodman, a bioethicist at the University of Miami, after reviewing a summary of the presentation.