In a small brick building across the street from a Taco Bell in Marrero, La., patients enter a clear plastic capsule and breathe pure oxygen.
The procedure, known as hyperbaric oxygen therapy, uses a pressurized chamber to help scuba divers overcome the bends and to aid people sickened by toxic gases. But Dr. Paul G. Harch, who operates the clinic there on the outskirts of New Orleans, offers it as a concussion treatment.
One patient, Rashada Parks, said that she had struggled with neck pain, mood swings and concentration problems ever since she fell and hit her head more than three years ago. Narcotic painkillers hadn’t helped her, nor had antidepressants. But after 40 hourlong treatments, or dives, in a hyperbaric chamber, her symptoms have subsided.
“I have hope now,” Ms. Parks said. “It’s amazing.”
Three studies run at a taxpayer cost of about $70 million have all come to a far different conclusion. They found that the benefits of hyperbaric oxygen reported by patients like Ms. Parks may have resulted from a placebolike effect, not the therapy’s supposed ability to repair and regenerate brain cells.
But undeterred, advocates of the treatment recently persuaded lawmakers to spend even more public money investigating whether the three studies were flawed.
A growing industry has developed around concussions, with entrepreneurs, academic institutions and doctors scrambling to find ways to detect, prevent and treat head injuries. An estimated 1.7 million Americans are treated every year after suffering concussions from falls, car accidents, sports injuries and other causes.
While the vast majority quickly recover with rest, a small percentage of patients experience lingering effects a year or longer afterward. Along with memory issues, symptoms can include headaches, dizziness and vision and balance problems.
Over the last decade, the Defense Department has spent more than $800 million on brain injury research, with organizations and companies like the National Football League and General Electric spending tens of millions more. And as people become more aware of the debilitating long-term consequences of repeated concussions, businesses have been chasing salable solutions.
The search for ways to treat and prevent concussions has spawned screening tools, helmet sensors, electronic mouthpieces, diagnostic blood tests and brain imaging devices. Start-ups are marketing their products to the military, schools, hospitals, sports teams and parents, and controversial therapies like hyperbaric oxygen are being promoted to patients.
But as the industry booms, medical experts are raising concerns that it is a business where much of the science is sketchy, belief frequently outruns fact, and claims of technological breakthroughs evaporate soon after they are made.