New research finds that oxygen therapy, administered in the same type of pressurized chamber used to treat scuba divers for decompression sickness, works no better than compressed air for treating troops with lingering symptoms of concussion.
Hyperbaric oxygen, or HBO, therapy has been praised by some in the medical community as well as head injury patients as a drug-free treatment for post-traumatic stress disorder, traumatic brain injury and post-concussive symptoms.
But several military studies, including the latest published Monday in JAMA Internal Medicine, say otherwise.
In research involving 72 service members with chronic post-concussive symptoms, physicians found that patients who received a series of 40 oxygen therapy treatments in a pressurized hyperbaric chamber did see significant improvements in their symptoms — but so did those who were treated with slightly pressurized regular air in a chamber.
The only patients who didn't see any improvements were those who had no treatments.
The research indicates that improvements in patients following HBO therapy may be related to a placebo effect and not to the oxygen itself, according to the military and civilian researchers who conducted the study at military hospitals in Colorado, North Carolina, California and Georgia.
The scientists postulated that the improvements in both groups could be related to the intensity of the treatments themselves, which involve "a ritual experience consisting of two hours of daily social interactions with a dedicated team of nurses and hyperbaric technicians as well as other participants."
The research is the latest in a series of studies by the Defense Department aimed at determining whether oxygen therapy heals a concussed or injured brain.
At least two previous military studies have found that in combat veterans with chronic post-concussion syndrome, HBO works no better than a placebo.
But advocates and patients say the therapy works, and point to the treatment success and research of Dr. Paul Harch, a hyperbaric medicine doctor and leading researcher of HBO for head injuries and wound healing, and others who have found HBO improves physical condition and cognitive acuity.
A study published in 2012 in the Journal of Neurotrauma by Harch found that treatment with oxygen significantly improved function and quality of life for veterans with TBI, PTSD, post-concussion syndrome and depression nearly three years after their injuries.
Retired Army Reserve Brig. Gen. Patt Maney, an Okaloosa County, Florida, judge who was injured in an explosion in Iraq in 2005, attributes his ability to continue working to HBO treatments.
"My wife literally led me around everywhere I went. I couldn't remember how to go places, what I was supposed to do when I go there, I couldn't carry on conversations," Maney said during a symposium on HBO in Arlington, Virginia, in 2011.
Nearly a fifth of combat veterans in Iraq and Afghanistan have received one or more blast-related concussions, according to the Veterans Affairs Department.
About 80 percent of the nearly 300,000 brain injuries suffered by troops in the past 13 years have been classified as mild traumatic brain injury or concussion. Effects of concussion, including sleep problems, headaches, nausea, balance problems, vision and cognitive issues, can linger for months and, scientists now think, even years.
With so few options for treating persistent post-concussive symptoms, PTSD and other brain-injured related conditions, researchers are exploring pharmacological treatments and alternative therapies such as acupuncture, oxygen therapy, mindfulness meditation and other solutions for eliminating brain injury symptoms.
Earlier this year, the House Appropriations Committee acknowledged the discrepancies between the positive research, the anecdotal success stories and the Defense Department's findings as well as the department's reluctance to prescribe oxygen therapy.
Committee members included in the fiscal 2015 defense appropriations bill a provision that requires the Government Accountability Office to provide a report to Congress on DoD HBO research as well as private sector studies to determine whether the trials were "appropriately administered" and examine the similarities and differences in the research.
That bill remains in Congress with some version of it expected to pass by the end of the year.
In the JAMA Internal Medicine article, Army Col. Scott Miller, director of the U.S. Army Medical Materiel Development Activity's HBO research team and others concluded that the evidence does not support additional clinical trials on HBO to treat post-concussive syndrome.
In commentary also published in JAMA Internal Medicine on Monday, Dr. Charles Hoge, with the Center for Psychiatry and Neuroscience at the Walter Reed Army Institute of Research in Silver Spring, Maryland, and Dr. Wayne Jonas, president of the Sameuli Institute in Alexandria, Virginia, said since the new research is consistent with two other clinical trial results, it is difficult to argue for further research.
While they described the conclusion as "disappointing for service members and veterans experiencing war-related symptoms," they urged colleagues to embark on more research on the biological causes of PTSD, concussion and other war-related injuries.
They also proposed exploring why the service members responded well to both the sham and oxygen treatments.
"What is clear [from the research] is that this was a healing environment. Factors such as enhanced expectancy, conditioning, the authoritative context of care and social reinforcement likely contributed, as well, perhaps as the prolonged break from the stresses of work," they wrote. "Hyperbaric oxygen treatment does not work but the ritual of the intervention does."
Patricia Kime is a senior writer covering military and veterans health care, medicine and personnel issues.
