Making an impact on the diagnosis of traumatic brain injury
By Roger P. Smith, Ph.D.
What do battered women, athletes in contact sports such as football, and veterans of the Iraq and Afghanistan conflicts have in common? They are all at risk of suffering from acquired traumatic brain injury. Some such injuries are so severe they're immediately apparent, even to nonprofessionals. Other victims may have what's commonly called a concussion and is known to doctors as mild traumatic brain injury (mTBI)—a much more subtle and difficult problem to diagnose.
One of the confounding factors, especially in veterans, is that mTBI can be confused with post-traumatic stress disorder—or the two conditions may coexist in the same individual.
Symptoms: Sleep disturbances, fatigue, and irritability are symptoms common to both syndromes, while dizziness, blurred vision, impaired balance, and sensitivity to light and noise are characteristic of mTBI. Since the treatment for the two conditions is different, it is important to distinguish between them. Dartmouth is now helping the military set up a new way of doing so.
Elizabeth Pearson, M.S.W., of DMS's Department of Pediatrics has devoted most of her career to the study of mTBI in battered women. She was the first person to use a powerful software tool to assess the extent of their injuries. The tool, called ImPACT, developed by Mark Lovell, Ph.D., director of the University of Pittsburgh's Sports Medicine Concussion Program. For the past 10 years, ImPACT has been the most widely used concussion management software in the National Football and National Hockey Leagues.
Test: The computerized ImPACT test can be administered by a nonclinician with minimal training. It takes about 25 minutes and consists of memory tests, such as word recall exercises, and spatial orientation tests based on geometric shapes.
If Pearson was the first person to see the test's potential to help battered women, it was Lt. Col. Patrick Tangney, M.D., state surgeon of the Maine Army National Guard, who—on learning of Pearson's work—saw its potential to help veterans.
"The percentage of American troops who are surviving battle wounds has risen dramatically," says Tangney, as a result of advances in both battlefield armor and treatment capabilities. And mTBI is an increasing concern for U.S. troops, since the weapons they most often face in Iraq and Afghanistan are improvised explosive devices and rocketpropelled grenades—both of which are highly likely to cause concussive brain injuries.
What Tangney realized is that if a base line brain-function test could be performed for all soldiers, diagnosing mTBI would then be much easier.
"The best standard for normal performance in a given individual would be his or her test results before injury," he explains. But "whereas one cannot predict what particular athlete is going to sustain a concussion or what woman is likely to be battered, one certainly knows when a given National Guard unit is going to be sent into harm's way." So the plan is to give the ImPACT test to soldiers before a unit is deployed and then test them again after their return.
DMS has signed on to assist with the initiative, and Pearson, who has experience working in the Mainemental health system, is serving as its director. She's helping the Maine Guard launch the screening program and advising mental-health providers in the state on how to identify and care for mTBI patients.
Rate: "This project will help maximize available resources," she says, "so that all of our service members have the highest rate of recovery."
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