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 concussiontreatment.
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.
Michael Singer, the chief executive of BrainScope, a company that makes a hand-held brain-wave measuring device cleared by the Food and Drug Administration to help assess injuries, says that while some companies are studying their products before selling them, others are selling untested products or marketing them without seeking regulatory approval.
“It is a Wild West out there,” he said.
Not long ago, the field of brain injury research was small. Numerous attempts to develop drugs to treat patients with significant head injuries failed as researchers struggled to understand the brain’s complexity. Little attention was paid to concussion, which is also called mild traumatic brain injury.
“The number of neurologists interested in traumatic brain injury could have held a convention in a phone booth,” said Dr. Ramon Diaz-Arrastia, an expert at the Uniformed Services University of the Health Sciences in Bethesda, Md. That changed a decade ago after reports showed that hundreds of thousands of service members were returning from Iraq and Afghanistan impaired by concussions caused by battlefield blasts and accidents. In 2007, Congress, facing criticism that the military had ignored the psychological and physical toll of the conflicts, allocated $600 million for research and treatment, splitting the funds between traumatic brain injury and post-traumatic stress disorder, or PTSD.
The Defense Department went on a spending spree. It funded dozens of studies to find a concussion treatment. Some studies examined supplements, others looked at drugs like Lipitor, the cholesterolmedication, and still more trials tested medical devices. Research was also underwritten to develop blood tests to better identify soldiers with concussions and to create improved imaging tools to map a concussion’s impact on the brain.
Dr. David X. Cifu, a professor at Virginia Commonwealth University in Richmond who also works for the Veterans Affairs Department, said that the hundreds of millions of dollars in government funds spawned a research feeding frenzy that led to dubious claims.
“It was a small field that got amazingly large because a lot of people were making stuff up and claiming things,” Dr. Cifu said.
Some specialists said they believed the military’s approach to concussions suffered from a basic problem. While agreement exists on the symptoms that define a concussion at the time when one occurs, a similar definition did not — and still does not — exist to describe what happens after a concussion, including how the injury’s symptoms change over time.
In addition, many soldiers who are diagnosed with a mild brain injury also have PTSD, a defined condition with symptoms similar to those associated with a concussion. Some critics within the military argued it was overestimating the concussion problem and channeling patients into the wrong type of treatment.
“They would get the message they had a serious brain injury,” said one of these critics, Dr. Charles Hoge, a psychiatrist at Walter Reed Army Institute of Research.
Whatever the case, the inability to separate PTSD from concussion turned the government’s research program into a scientific hodgepodge. A 2013 Veterans Affairs review of studies of mild traumatic brain injury, or M.T.B.I., in soldiers and veterans found that the studies’ overall quality was poor, and it was impossible to separate long-term impacts unique to concussion from those attributable to PTSD.
Col. Dallas Hack, a doctor who oversees the Army’s research program, said officials realized several years ago that the military’s efforts had gone off-course and a lot of money had been spent on studies that produced little in the way of tangible results. Since then, the Defense Department has refocused its efforts on basic questions, such as developing a better definition of concussion.
“We were naïve” at the start, Colonel Hack said.
A few years ago, a major producer of football helmets, Riddell, announced that it was on the trail of the concussion chase’s Holy Grail: a way to reduce injuries by using electronic impact sensors to monitor head blows. The National Football League was so enthusiastic about the technology’s potential that it studied the performance of impact sensors in the Riddell helmet in eight N.F.L. games.
But the league ended the experiment, saying the data produced by the sensors was too crude to be of value. “You couldn’t fully appreciate the magnitude and the location of a hit,” said Jeff Miller, the senior vice president for health and safety policy for the N.F.L.
The end of the N.F.L’s field test, however, hasn’t dimmed enthusiasm for sensors among coaches and parents. In the fall, players on several college football teams, including the University of South Carolina and the University of Texas, will take the field wearing mouth guards equipped with sensors made by a small company, i1 Biometrics.
As with much in the concussion business, experts are still uncertain whether the data produced by impact sensors will result in fewer concussions or simply create statistical noise that adds to parents’ anxiety. Sensors “can serve as a second set of eyes, but they cannot diagnose concussions,” said Blaine Hoshizaki, a professor at the School of Human Kinetics at the University of Ottawa.
Impact sensors vary in design, but they are intended to serve as early warning systems that may help reduce concussions. A sensor records the movement of a player’s head and can be set to light up or send a signal to a cellphone or monitoring station when that movement is very abrupt, such as when a player is tackled hard. At that point, the player can be examined and, if needed, taken out of a game.
With growing demand, the cost of sensors, which are mass produced in Asia, has dropped sharply. Helmet makers can easily charge double for a helmet containing them, and such products are available not only in football, but also hockey, lacrosse, cycling and other sports.
In March, nearly 100 corporate executives, entrepreneurs and researchers crammed into a conference room at Virginia Tech, in Blacksburg, Va., for a one-day seminar “Head Acceleration Measurement Sensors.” Some two dozen companies make such sensors, and the March meeting was attended by companies with names like Triax Technologies and Brain Sentry, as well as helmet producers like Schutt Sports, which makes football gear, and Trek, the bicycle maker.
One presenter at the meeting discussed an earpiece with a sensor inside it, while i1 Biometrics demonstrated its sensor-containing mouth guard.
Jesse Harper, the company’s president, said in an interview that i1 Biometrics first tested the device in laboratories and then on cadavers, whose skulls were struck to record the device’s ability to detect motion. “It’s not the most cocktail-friendly conversation,” Mr. Harper said of the cadaver tests.
After tests on players proved successful, the company started selling the device last year to high schools and a number of colleges. The mouth-guard system costs $199 a player, Mr. Harper said.
Currently, however, there is no consensus among coaches about the strength of a sensor reading that would lead to pulling a player out of a game. While one player might absorb a strong head blow without ill effect, the same force would stagger another one.
Mr. Harper added that the schools and colleges buying his company’s mouthpiece could also use it as a training tool to study the position of a player’s head when struck and potentially work on ways to reduce the most harmful impacts. But some experts say they believe that sensors are still not ready for widespread use.
Mr. Miller, the N.F.L. executive, says he thinks the sensors are likely to improve. But last year, when the league, General Electric and Under Armour announced the award of $8.5 million in competitive grants to companies developing promising concussion-related technologies, not a single sensor producer was among the recipients.
Dr. Harch, the New Orleans-area physician, is a true believer in the benefits of hyperbaric oxygen. In his book, “The Oxygen Revolution,” he claims the treatment not only helps treat post-concussion syndrome, but also autism and Alzheimer’s disease.
One major professional medical group, the Undersea and Hyperbaric Medical Society, has said there is no evidence showing the technique is effective in resolving concussion symptoms. “I don’t offer this treatment in my facility for mild traumatic brain injury because I’m not convinced it works,” said Dr. Enoch T. Huang, an official at the society and a specialist at the Adventist Medical Center in Portland, Ore.
Dr. Harch acknowledges that he is in the minority. “My generation of doctors thinks this is a fraudulent theory,” he said. Many years ago, he and other advocates formed a competing professional group, the International Hyperbaric Medical Association, which has lobbied to get coverage for the treatment.
The military has also been skeptical and for a time refused to fund hyperbaric oxygen research. But facing intense lobbying from lawmakers and veterans groups, the military agreed to start several trials.
“We just had to do the study and put it to rest,” said Carl Castro, a professor at the University of Southern California and a retired Army colonel once involved in overseeing military concussion research.
Conducting those studies posed a challenge. Researchers were concerned that because hyperbaric oxygen therapy is so intense — a patient typically takes five dives a week over two months — the benefits patients experienced were more psychological than physical.
To address that issue, researchers divided patients into groups. One got hyperbaric oxygen therapy. Another got so-called sham procedures, in which patients sat in a chamber pressurized slightly to create the feeling of treatment, but instead of pure oxygen received room air, which is about 20 percent oxygen.
“We had no idea what we’d find,” said Dr. Lindell K. Weaver, a hyperbaric expert at the LDS Hospital in Salt Lake City who worked on the studies.
Those trials found that patients who had a real treatment or a sham treatment reported similar benefits, pointing to a placebo effect. But if Defense Department officials hoped the results would end the debate, they were wrong.
Late last year, hyperbaric oxygen proponents started a new lobbying campaign, arguing to lawmakers that the studies’ conclusions were misleading because patients who had received sham procedures were still getting the treatment, though at a lower dose. They pointed to other studies with positive findings and claimed the government did not want to pay for the hyperbaric oxygen because of its cost. Dr. Harch estimated that, depending on location, the price of a series of 40 dives typically ranged from $5,000 to $12,000.
Sympathetic lawmakers responded by putting language in the most recent congressional budget bill requiring the Government Accountability Office to review whether the military trials had been run properly. Many of those lawmakers were the same ones who had lobbied the military to run the trials in the first place.
Representative Walter B. Jones Jr., Republican of North Carolina, said he supported the accountability office review. He has introduced a bill that would require Veterans Affairs to pay for the treatment if prescribed by a doctor and said he believed that hyperbaric oxygen, even if it just made patients feel better, should be used instead of dangerous psychotropic drugs that veterans are often given.
“No one has committed suicide from being treated with oxygen,” Mr. Jones said.
Medical experts say that after a decade of intense focus, there is a heightened awareness of the consequences of concussions. The military has adopted new battlefield procedures to examine soldiers, new research is underway and schools are far more vigilant in making sure students are checked out after a head injury.
Experts say that the most effective treatment is addressing each of a patient’s symptoms individually, and in some ways, the search for new approaches has returned to the starting line. A concussion expert with the Mayo Clinic, Dr. David W. Dodick, said he believed a cheap nutritional supplement, N-acetylcysteine, could help treat concussion symptoms, and he hoped to study it.
It would not be the first time that the supplement, which is an antioxidant, has been tested for that use. In 2008, the Defense Department began a study of the supplement in soldiers in Iraq who had sustained a concussion. That trial showed benefits, but the study quickly became engulfed in controversy.
Dr. Dodick said that the dispute about the trial overshadowed a possible breakthrough and that N-acetylcysteine might be a valuable tool. “Every coach and parent could be carrying this on the sidelines,” he said.
Some researchers have also started trials of hyperbaric oxygen, and Dr. Harch is working on a trial he believes will provide compelling data about the treatment. Funding for the $1.2 million trial was originally allocated in 2008 as part of legislation backed by Louisiana’s congressional delegation, but the study was delayed.
An advertisement recruiting patients for the trial states, “If You Continue to Have Symptoms From a Mild Concussion You Experienced While Playing Sports, In a Car Accident, or During Military Service, You May Qualify.”