BAL HARBOUR, FLA. -- Clinicians across the country are facing the realities of the war in Iraq, as veterans with concussive blast brain injuries rejoin their communities. These soldiers are also giving researchers valuable insight into the way concussive forces disrupt brain function. Dr. Deborah Warden said at the annual meeting of the American Neuropsychiatric Association.
Because closed brain injuries due to blast are uncommon in civilian life, they have not been well studied, said Dr. Warden, director of the Defense and Veterans Brain Injury Center at Walter Reed Army Medical Center in Washington. Until now, most of the research has focused on blast injuries to the extremities or torso, and on penetrating head injuries caused by shrapnel. Since those injuries are usually life threatening, they are typically immediately identified and cared for. But closed head injuries may be overlooked.
"Data on blast-induced brain injury are limited," Dr. Warden said. "While this type of injury and the resultant cognitive dysfunction have been described in rat studies, the clinical characteristics of blast injury in humans are not well described in the literature."
This lack of data can contribute to problems some veterans with undiagnosed traumatic brain injury experience when they return to their communities. Although their obvious combat injuries have been treated, they may experience postconcussive symptoms that puzzle their physicians and leave the veterans questioning their own sanity. Those neurocognitive changes typically manifest as a reduced capacity for information processing, including problems with attention, concentration, and new learning, and slowed cognitive-processing speed.
"People think they're going out of their minds," Dr. Warden said in an interview. "They know they don't feel right, but they don't know why. They may be more irritable and have a lower tolerance for frustration. They may not want to be around crowds and feel insecure about their thinking, experiencing distractibility, memory problems, and a lack of concentration and focus."
Those symptoms result from a concussion caused primarily by an overpressurization wave that travels at the speed of sound. While air-filled organs are especially susceptible, the brain is vulnerable to direct injury from cerebral contusion or indirect injury--a cerebral infarction secondary to air emboli.
Understandably, Dr. Warden said, concussive brain injuries often go unnoticed in combat theater hospitals. Many soldiers who incur brain injuries present with much more obvious, lifethreatening problems: shrapnel wounds, amputations, and burns.
"These are people who walk and talk and pass for normal," Dr. Warden said. "Everyone is telling them, 'It's OK. You're fine now,' but they are thinking, 'No, it's not. I'm not thinking right.'"
Since the symptoms of postconcussive syndrome are ego dystonic, she said, the patient might try to adapt to this new, negative vision of himself, thinking that he is fundamentally changed forever. "Fortunately, the prognosis is generally good for these people," she said. "They do tend to get better over a period of time."
In an effort to better identify those closed head blast injuries and to track patients' long-term recovery, injured soldiers at risk for traumatic brain injury are now being screened. The group includes patients who have been involved in blasts, as well as those who have had amputations, falls, and motor vehicle accidents while serving in Operation Iraqi Freedom and Operation Enduring Freedom (the ongoing operations in Afghanistan).
After being stabilized, patients receive a cognitive screening and / or full neuropsychological evaluation, and audiologic, psychosocial, and psychiatric evaluations. EEGs and magnetic resonance spectroscopy are performed if clinically indicated.
To date, 155 patients injured in combat have been screened for traumatic brain injury; 57% of the group (88 patients) had been involved in blasts, and 54 of those patients had sustained a blast-related brain injury. …