Credit: Artem Chernyshevych | Stock Xchng
Credit: Artem Chernyshevych | Stock Xchng
As soon as word got out that Rep. Gabrielle Giffords (D-Ariz.) had survived a bullet wound to the brain, one question seemed to reverberate throughout the nation: Would she be OK?
Her surgeons have been optimistic about her condition in recent days, but they cannot say with certainty what her recovery will be like. While swift action and modern medicine can save the lives of those who suffer traumatic brain injuries, understanding what life will be like afterward is a different story.
Despite the growing research regarding these types of injuries — and the cultural attention they've received, especially because of their increasing prevalence among veterans and professional athletes — recovery from a traumatic brain injury is unpredictable, researchers say, and forecasting the final outcome remains difficult.
"We are not very good at it, to be honest," said Dr. Deborah Stein, chief of critical care at the University of Maryland School of Medicine's Shock Trauma Center. "Each individual is very different. We sometimes see some very small-looking injuries that cause major, major dysfunction. And we see some very large-looking injuries that people do very well with," Stein said. "The brain is an unbelievably complex organ."
But new technologies, and ones on the horizon, might soon change that. Brain imaging techniques used in research are starting to find their way into hospitals, letting doctors see which parts of the brain aren't working, and might one day allow more accurate prognoses. Researchers are also investigating using biological markers to diagnose mild brain injuries, or indicate how recovery will progress. And technologies that stimulate brain cells might aid a patient's recovery process, researchers say.
Here are some promising technologies and ideas that experts say could improve lives of traumatic brain injury patients.
Functional Magnetic Resonance Imaging (fMRI) lets doctors look at the brain's activity, rather than just its parts. While this technique has been around in research settings for a while, it has only been used clinically in the last three or four years, said Dr. Brent Masel, a traumatic brain injury expert at the Transitional Learning Center at Galveston, Texas.
Peering at the brain's function lets physicians catch problems that might not show up on an image that just shows the brain's structure, said Dr. Maurizio Corbetta, a professor of neurology at Washington University School of Medicine in St. Louis. And the earlier doctors find problems, the sooner they can address them and the better the outcome will be, Masel said.
In addition, fMRI may let doctors see whether intact parts of the brain are accommodating for injured parts, he said. And pairing a patient's fMRI with a study of his or her behavior may help researchers better understand which brain areas are responsible for which activities — such as emotions and movement — a daunting task scientists are grappling with.
Another technique called diffusion tensor imaging lets researchers look at the brain's white matter and see how it is changing. White matter forms "cables" in the brain that allow areas to communicate. In the past, researchers could only examine white matter at autopsy, Corbetta said.
"We use to think that brain injury was a pretty static process," Masel said, "That you had your brain injury and then, once you got medically stable, everything else was on an up trajectory." But in a recent study, Masel found that the white matter may deteriorate over time.
"Brain injury is a chronic disease," he said.
Stimulating the brain
Technologies that stimulate brain cells to fire, or change how excitable they are, may also aid in rehabilitation, Masel said. Two such techniques are transcranial magnetic stimulation and transcranial direct current stimulation.
These methods may help prevent the two hemispheres of the brain from getting in each other's way as the brain recovers, Masel said. For example, if a brain injury leaves one hemisphere damaged and one intact, the healthy hemisphere may try to block messages from the injured side, preventing the injured side from getting better, he said.
Interfering with brain cells' activity may allow researchers to "turn down…the good side of the brain, so that the bad side of the brain has a better chance of improving," Masel said.
Certain biological markers in the blood or spinal fluid may also help researchers distinguish between patients who will have good and poor outcomes.
Stein and her colleagues found one marker, a protein called interleukin-8, which yields clues to how well a patient may recover. Interleukin-8 is released by cells in response to inflammation.
The researchers found patients with poor outcomes — those who died, were in a persistent vegetative state or exhibited poor brain function after their injury — had higher levels of interleukin-8 than those with better outcomes.
Many other markers are under investigation, including substances
released from nerve cells when they die. It's possible a blood test that
looks for such markers could indicate when a patient has suffered a
mild traumatic brain injury, even if the injury doesn't appear on brain
scan, Stein said.
However, researchers are far from being able to use these markers in diagnoses or prognoses, Stein said.
Sharing their notes
Creating a national registry or database, of patients with traumatic
brain injuries might also improve doctors' ability to make prognoses,
Currently, doctors usually make predictions about recovery based on their own experiences with past patients, he said. But seldom does one doctor see many of these injuries, and patients can vary greatly in their injuries and recoveries. A national registry would allow doctors to make comparisons on a much larger scale.
"It's multiplying the doctor experience by thousands of patients," Corbetta said.
A registry might collect information about the physical and mental state of patients at each stage of their recoveries, and together, the information would give doctors a picture of how patients with similar injuries might fare in the long run. Such information would also allow doctors to more precisely cater rehabilitation care to each individual, Corbetta said.
"I think having this information at your fingertips and having ways to make predictions based on real data, and not just your doctor experience…I think that would really be a breakthrough in caring for this condition," Corbetta said.
Pass it on: New technologies and ideas on the horizon may help doctors make better prognoses for traumatic brain injury patients.
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