July 8, 2010
Traumatic brain injury: A leading cause of death without a champion
Twenty years ago, Dr. Randall Chesnut went to Argentina to give a lecture on brain injury, a leading cause of death and disability worldwide and especially acute in Latin America.
What he found was a passionate core of physicians wanting to help survivors of traumatic brain injuries but hindered by key scientific knowledge on how to treat these patients.
A few years later, these physicians formed the Latin American Brain Injury Consortium (LABIC) and received a grant from the National Institute of Disability and Rehabilitation Research to look at brain injury outcomes. They started a database and identified a core group of investigators to make high-level research occur.
Today, LABIC Investigators are teaming with Chesnut and North American researchers on a series of projects sponsored by the U.S. National Institutes of Health and industry sources. This includes surgical and medical treatment of TBI and the influence of evidence-based treatment guidelines on medical practice and outcomes.
“These researchers carve out time in their schedule to work on this because they want answers,” said Chesnut, a professor of neurological surgery at Harborview Medical Center and an adjunct professor in UW’s Department of Global Health.
He called TBI an “orphan disease” because it has no celebrity champions or media status and very little funding. He said there are no major foundations focused on this problem and U.S. federal research sponsorship is extremely small and budgets for existing award have been severely reduced.
But the problem is huge.
The 1996 Global Burden of Disease Report places trauma as the leading cause of death and disability for people under 45 and TBI as the primary cause across all age groups. According to the report, the Latin American and Caribbean region had the highest incidence of intracranial injury worldwide secondary to road traffic accidents and to violence. The rate was 1.5 times that of the world average. With increased growth in the use of cars, scooters and motorcycles, especially among the young, TBI is a devastating problem. So far, there is no cure for someone with a severe head injury but there are ways of mitigating the trauma that need more study, said Chesnut.
“Developing effective treatment is hampered by the lack of scientific knowledge,” he said. “This is particularly true in developing countries, where our models may not work well.”
In 2007, the group received a five-year $3.2M grant from the National Institutes of Health (NIH) Fogarty International Center and the National Institute on Neurologic Diseases and Stroke (NINDS) to evaluate overall outcomes to understand the care these patients receive and how this care affects outcomes. This includes the first international randomized controlled trial on traumatic brain injury the NIH has ever funded and is the first study of its type in Latin America.
As part of this study, researchers are looking at intracranial pressure (ICP) management — the standard method of care for TBI patients in the United States and Europe. Raised intracranial pressure means that both nervous system (neural) and blood vessel (vascular) tissues are being compressed and could result in permanent neurologic damage or death.
Included in this study is examining the effectiveness of ICP monitors, which are inserted into the brain by a neurosurgeon to measure the intracranial pressure. Chesnut said almost every scientific paper on head injury calls for lowering intracranial pressure if the intracranial pressure is greater than 20 mm (millimeters of mercury).
But, Chesnut said, there is very little evidence on the effectiveness of lowering intracranial pressure and whether an ICP of greater than 20 mm is the right threshold.
“ICP monitoring has become a standard of practice even though the evidence is weak,” he said. “If 20 mm is the wrong threshold for treating, then having this treatment at the core of brain injury management could be inhibiting science.”
Dr. Juanita Celix, a UW neurosurgeon consulting on the study, said if ICP monitors are proven to not be effective, then it could lead the way to look at more effective treatment methods and open the door into more research. And if the monitors are found to be effective, it could set new policy in countries that do not have a trauma system.
Researchers said the idea for the study came from Bolivian intensive care specialists who weren’t sure that, if they had the money, they should spend it on costly monitors (upwards of $700 a piece). Since Latin American countries did not routinely use ICP monitors, the study was conducted there.
The randomized controlled trial is evaluating ICP management at five centers in Ecuador and Bolivia. An estimated 270 patients will be studied.
The implications for the study could have widespread impact on global head injury treatment guidelines.
“The research by Dr. Chesnut and his colleagues addresses a major health problem –the need for high quality evidence to inform clinical care guidelines for TBI,” said Ramona Hicks, Ph.D, program director for TBI research at the NINDS, one of the funders . ” It’s exciting to see a team of investigators with such a successful and productive track record apply their expertise to this important, but also challenging international study.”
Because the brain and nervous system don’t repair themselves, the best physicians can do now, said Chesnut, is provide an optimal healing environment and avoid what he calls “secondary insults” — low blood pressure, low oxygen, fever and inadequate blood flow.
Meanwhile, researchers keep finding new areas of study, such as the large volume of head injury patients in Latin America that are not seen in intensive care units because there are no beds. These so-called “orphan patients” are managed by various medical teams outside the ICU.
Also, blast injuries from the wars in Iraq and Afghanistan are causing a new epidemic in mild traumatic brain injury, said Celix, who is getting a master’s of public health at UW. A RAND telephone survey released in 2008 found that 20 percent of U.S. soldiers are returning with a mild form of TBI, but the impact on civilians in these countries is unknown.
“We need to define the problem better among civilians,” she said.