Health problems linger in concussed veterans
Symptoms from head trauma in Iraq linked to post-traumatic stress disorder.
US soldiers who became concussed during deployment in Iraq are more likely to report poor general health than are veterans with other injuries, a study has found.
But questions remain about what causes those lingering health problems: the physical blow to the head, or the emotional trauma associated with violent experiences. A study released today, in the New England Journal of Medicine, notes that the link between concussion and poor health might have resulted from higher rates of post-traumatic stress disorder in those with head injuries1.
"The possibility that symptoms could be accounted for by emotional disorders such as post-traumatic stress disorder is very important for us to know," says Roger Pitman, a professor of psychiatry at Harvard Medical School in Boston, Massachusetts. "We have to be very careful about who we call 'brain-damaged', because of the possible adverse effects of labelling people in this way."
Traumatic brain injuries are the most common physical injury seen in troops deployed to Iraq and Afghanistan — largely thanks to improvised explosive devices. They have been designated a 'signature' of the two conflicts.
The injuries can range from mild traumatic brain injury, better known as a concussion, to severe head traumas. Many veterans with mild brain injuries have reported lingering symptoms, including memory problems, headaches and difficulty concentrating. A recent military survey of 35,000 soldiers found that as many as 20% had been concussed and that 20-40% of those might have residual symptoms of their injury.
Dazed and confused
Most studies on the long-term effects of concussion have been done on civilians, particularly athletes, and have yielded mixed results. A World Health Organization task force on mild traumatic brain injury surveyed the available literature and concluded that most patients recover within a year of their injury2. But a US Centers for Disease Control and Prevention report in 2003 referred to traumatic brain injury as a 'silent epidemic’, and cautioned that available data may underestimate problems associated with concussion.
Charles Hoge of the Walter Reed Army Institute of Research in Silver Spring, Maryland, and his colleagues surveyed 2,525 infantry soldiers from the US army after their return from a year-long deployment in Iraq.
Hoge and his colleagues found that simply feeling confused or disoriented from a blast was not associated with poorer health later. But soldiers who had lost consciousness (usually for half an hour or less) continued to experience a wide variety of symptoms, ranging from headaches and chest pain to memory and balance problems. These symptoms were more common in soldiers who had been concussed as the result of a head injury than in those who reported other forms of injury.
But that difference disappeared when post-traumatic stress disorder was taken into account. “Those who had a loss of consciousness were at a much higher risk of having post-traumatic stress disorder,” says Hoge, “and that was correlated with a variety of health concerns.” 44% of those who had lost consciousness for 30 minutes or less had post-traumatic stress disorder, compared with 16% of those with other injuries, and 9% of those with no injuries.
Hoge attributes the higher rates of post-traumatic stress disorder to the trauma surrounding the injury rather than the injury itself. “Concussion during a deployment is a very close call on one’s life,” he says. “It’s obviously a very life-threatening situation. We certainly don’t see post-traumatic stress disorder in football players who get a concussion.”
Richard Bryant, a professor at the University of New South Wales School of Psychology in Sydney, Australia, says that the physical injury could enhance the likelihood of post-traumatic stress disorder. One possibility, he says, is that traumatic brain injuries often involve a shearing of the brain with the front of the skull. That force could damage the part of the brain that regulates the amygdala — the region that regulates fear responses. “These neural networks that are required to regulate fear are impaired or diminished in people with post-traumatic stress disorder,” says Bryant.
Hoge says that it is important for soldiers to realize that post-traumatic stress disorder can be treated. “For the vast majority of servicemen coming back from combat duty who have had a concussion, there’s every expectation of recovery,” he says.
- Hoge, C.W. et al. N. Engl. J. Med. 358, 453-463 (2008).
- Carroll, L. J. et al. J. Rehabil. Med. 43 (suppl), 84-105 (2004).