Air Force Studies Brain Injuries

By Donna Miles
American Forces Press Service

Jan. 8, 2010 - Compression chambers used to treat divers who experienced "the bends" after ascending too quickly may offer clues to treating wounded warriors suffering traumatic brain injuries. An Air Force study at Wilford Hall Medical Center in San Antonio hopes to determine if hyperbaric oxygen therapy shows promise in treating patients with mild to moderate traumatic brain injuries.

A team with the San Antonio Military Medical Center Hyperbaric Center and Air Force School of Aerospace Medicine launched the study last year, and expects to come up with preliminary results as soon as this summer. The study seeks to determine if patients experience improvements in their cognitive abilities after being exposed to pressured, 100-percent oxygen in a hyperbaric chamber, explained Dr. E. George Wolf, a physician directing the study.

The goal is to improve the patient's ability to think, remember, recognize and concentrate. These abilities often are impaired in troops with traumatic brain injuries, many attributed to blows to the head, nearby explosions, concussion or penetrating wounds.

Twenty-five soldiers, sailors, airmen and Marines afflicted with TBI are currently participating in the study, with another 25 to join in the months ahead. Half are receiving hyperbaric therapy and half are in the control group that is not, although neither the subjects nor the researchers know at this point which subjects are in which group, Wolf said.

The subjects enter the room-sized hyperbaric chamber for 30 treatments over a course of six weeks, he said. Inside the chamber, a hood is fastened over the head to deliver pure oxygen. Pressure within the chamber drives more of this oxygen into the subjects' bloodstreams than they otherwise would receive.

The control group goes through the same procedure, but their chamber isn't pressurized, and they breathe standard air, a 21-percent oxygen concentration.

During the course of the treatments -- before, throughout and after the exposures are completed – the researcher gives the subjects a battery of tests designed to measure their cognitive abilities.

The study hopes to provide scientific evidence proving that the increased oxygen provided through hyperbaric therapy helps to restore abilities lost due to traumatic brain injuries.

Air Force Col. (Dr.) Robert Michaelson, chief of hyperbaric medicine at San Antonio Military Medical Center, said it's not yet fully understood why hyperbaric treatments may help TBI patients. One popular theory is that it helps to restart damaged brain cells that have stopped functioning properly.

"For some reason, and it is still unexplained, hyperbaric oxygen allows these cells to be turned back on by stimulating the production of energy within the cells," he said. "It seems to have a positive effect."

Another theory is that hyperbaric therapy mobilizes the body's stem cells, dispatching them to the brain to repair damaged neurons, Wolf said.

Regardless of why it may work, Wolf and Michaelson agree that if proven effective, hyperbaric oxygen therapy can mean life-changing differences for wounded warriors suffering from TBI. In the most optimistic projections, troops could return to normal functioning. Those who wish to remain on active duty, as many do, would be able to.

In other cases, the treatments could help to reduce patients' dependence on personal data assistants, hand-written notes and alarm clocks that many have come to rely on as ever-present reminders as they go about their day-to-day business.

"Hopefully, it will allow better lifestyle changes and actually treat the underlying cause, versus trying to cope with the symptoms," Wolf said. "It would be a great accomplishment if our study provides evidence that hyperbaric therapy can help these warfighters so they can be offered another opportunity to recover from their injuries."

As the study continues, the Defense Department is considering another, larger study to further explore the use of hyperbaric medicine in treating TBI, Michaelson said.