War carries many consequences, including the "invisible wounds" sustained by the brain: post-traumatic stress disorder, chronic pain, and concussions. At one session at the recent "Next Frontier of the Brain" forum in Boston, researchers described progress in treating these wounds, and what we need to do to learn how to heal all injured veterans, as well as their civilian brothers and sisters. The session was recorded by the Science Network (video and mp3 audio available) and you'll find it below; the science presentations start at the 20-minute mark.
Dana Alliance member Elizabeth Phelps of New York University began by describing the neurobiology of PTSD. "In normal fear, there's this delicate balance between these brain systems that assures that fear is expressed when there's a real threat, but when the threat has passed, and now you know the situation is safe, or when the context is safe, the fear is not expressed." What happens in PTSD, scientists think, is that this balance is disrupted. "So the amygdala [part of the fear circuit] now has a stronger influence on the expression of behavior, and it is not as easily inhibited."
This affects cognitive processing as well as emotional processing. For example, Phelps said, "Even though these patients tend to show very robust memories of the traumatic events that they don't seem to be able to forget, after they acquire PTSD they show relatively poor memory function in everyday life."
Current treatments work for some people, but psychotherapies rely on cognitive abilities that may be offline in those with PTSD, and while drugs resolve symptoms they may not fix the underlying problem. In addition to investigating new drugs, researchers are trying another approach: understanding resilience.
Up to one-third of combat veterans will show symptoms of PTSD, Phelps said. "But this means at a minimum about 70 percent of people who experience trauma do not develop PTSD, and the question is: Can we identify who they are?" There are signs that a number of factors may be linked to resilience, including prior life experience, social support, genetic variation, and neural vulnerabilities caused by traumatic brain injury or perhaps just due to individual variation. "All of these can work in combination with the nature of the trauma to promote resilience—or not," she said.
"If we understand what makes somebody resilient we could do one of two things: We could either not let those people who are vulnerable be exposed to combat situations, or, perhaps, we can develop new treatments that we can now make those vulnerable populations less vulnerable." [In the video, her presentation runs from the 20-minute mark to 37:00.]
Clifford J. Woolf, director of the program in neurobiology at Children's Hospital Boston, pointed out that when people count the costs of disease, they often miss the biggest one: "The commonest cause of complaint, why patients go to see their physicians, happens to be pain."
And while we have made enormous progress in promoting survival and great advances in rehabilitation, "in fact an area that has really lagged behind relates to the pain associated with combat injury," he said.
Pain is not a symptom but a disease state, a physical injury to the nervous system, Woolf said. "While plasticity is a critical component of how the brain enables us to learn and to retain information, the same modifiability of the nervous system can also contribute to disease states," he said.
A promising current approach to understanding pain is the same approach as that for PTSD – understanding individual differences. People with apparently identical injuries do not develop identical levels of pain—or any pain, sometimes, he said. Researchers are looking for genetic variations and also investigating the differences in people who have Mitchell's disease (a hypersensitivity to pain) and people who cannot feel any pain at all. "If we know who has a high risk of developing pain, the treatment may be quite different from those individuals who have a low risk," Woolf said. [In the video, his presentation runs from 37:30 to 55:03.]
Col. Geoffrey Ling of the Defense Advanced Research Projects Agency (DARPA) described how he and other military medical workers have reshaped their approach to traumatic brain injuries (TBI). He started by showing graphically what people in war zones experience, describing three of his patients and how timely treatment can lead to recovery from even serious wounding. [In the video, his presentation runs from 55:30 to 1:16:00.]
Then he showed a series of frightening video examples of explosions in a lab setting and in the towns and mountains of Iraq and Afghanistan, illustrating the violence of the blast itself and also the force of the shockwaves that flow out of it. The latter blasts injured and killed several people, and similar blasts continue to occur. "That's what the urgency of what we are doing is," Ling said.
Ling and his colleagues have created the first system-wide approach to concussion, including a diagnostic tool, clinical guidelines, return-to-duty guidelines, and mandatory TBI screening of all people near a blast.
Why mandatory screening? "Because these are not patients that come to you; these are patients we must go to," Ling said. "We had to change the paradigm of expecting somebody to report in and say 'I am hurt' when we realized that they may not know they are hurt—particularly the PTSD patients."
These guidelines are just a start, Ling said. "And we want to build on it," by publishing their results and experiences and learning from civilian experiences such as NFL players' records. "Where it goes now is research, research, research."
Elizabeth Phelps agreed. "It is my hope that, with the continued efforts of basic and applied research in brain science over the next decades, in the future when we see soldiers like this we can be fairly confident that none of them will suffer the debilitating effects of PTSD. And that all of our soldiers who survive the physical risks of war have the happy homecoming and bright future they so deserve."
The forum was held in Boston May 23–25 by the One Mind for Research campaign, whose goal is "to significantly reduce the U.S. burden of disability due to brain disorders." The campaigners released a blueprint of research goals at the event: "A Ten-Year Plan for Neuroscience: From Molecules to Brain Health" (PDF). Videos of all the sessions and interviews are collected on the Science Network site.
The Science Network also did a wide-ranging interview with Elizabeth Phelps, on memory, neuroethics, why she became a scientist, women in science, and what advice she'd give young scientists (43 min).