Cleveland Clinic’s Lou Ruvo Center for Brain Health here is, “How many times have you been knocked out cold or gotten a concussion?” Most say, “never.”
M.R.I. scans were used in the research. Some fighters had changes in their brains but showed no cognitive declines.
Then the doctors ask, “How many times have you felt dazed and stunned?” Most say, “many times.”
This is part of the Professional Fighters Brain Health Study, now a year old and with results from 109 fighters — more than have ever been compiled in a single research project. The principal finding: “There are detectable changes in the brain even before symptoms appear,” like memory loss or other changes in cognitive function resulting from repeated blows to the head, Dr. Bernick said.
The physical changes, detected by M.R.I. scans, are a reduction in size in the hippocampus and thalamus of the brains of fighters with more than six years in the ring. These parts of the brain deal with such functions as memory and alertness. While those who had fought for more than six years did not exhibit any declines in cognitive function, fighters with more than 12 years in the ring did. Thus, Dr. Bernick’s group concluded, the lag between detectability and physical symptoms probably occurs sometime during those six years.
Dr. Bernick will present these findings on Wednesday in New Orleans at the American Academy of Neurology’s annual meeting, and the potential significance goes well beyond the health of boxers. The idea that an M.R.I. could help identify a degenerative brain disorder before a patient reports cognitive problems could help a broad range of people, from young athletes and combat soldiers to others who have been subjected to repeated blows to the head, neurologists say.
There may also be implications for understanding Alzheimer’s and other diseases among otherwise healthy elderly people, but these issues remain subjects for further study, said Dr. Jay L. Alberts, director of the Cleveland Clinic’s Concussion Center. The Ohio-based clinic is the parent institution of the Las Vegas center.
“Everyone knows repeated blows to the head are not good for you,” Dr. Bernick said. “But nobody knows how you evolve from getting blows to developing long-term degenerative diseases. Now we have some sense of sequence.”
Like many doctors who study athletes’ brain injuries, Dr. Bernick has concluded that much of the research has focused too narrowly on infrequent, hard blows to the head rather than more constant lesser blows.
In other words, “We may not need to focus so much on concussions,” Dr. Bernick said. “It could be that sustaining thousands of blows that don’t knock you out could be more important” to assessing the long-term health of your brain.
Dr. Bernick’s results rest on the Las Vegas center’s ability to gather a large sample of professional boxers and mixed-martial artists, to classify them according to the amount of time they have spent in the ring, and to cross-reference M.R.I. images of their brains and results from cognitive tests.
“It’s the first study of its kind,” said Dr. Robert Stern, director of the Alzheimer’s Disease Clinical Core at Boston University School of Medicine, who was not part of the research team. “It’s the first time we have a large group of athletes who have their brains hurt on a regular basis, with M.R.I. images, cognition tests, and a longitudinal aspect,” added Dr. Stern, who plans to conduct a similar study of former National Football League players.
Though Dr. Bernick intends to continue his study of boxers for at least five years, he said the preliminary findings were worth the attention of the neurology association’s annual meeting, as “nobody has the numbers we do.” And he hopes, eventually, to help inform decisions made by boxers and state boxing commissions, as well as sports medicine generally, when it comes to preventing neurodegenerative conditions.
Dr. Alberts of the Cleveland Clinic in Ohio said that brain damage caused by strong concussive blows versus lesser, but more frequent, hits was “a distinction that people are talking about, but at the moment we have no data, just a lot of hand-waving.” He said the study of boxers should help change that.
At the Las Vegas center, only three years old, there are plans to include hundreds more boxers in the next five years. For now, the brain images of 109 fighters are grouped according to the length of time each participant has fought: less than 6 years, 6 to 12 years, and more than 12 years. The number of fights is also taken into account.
Given that Las Vegas is billed as the “fight capital of the world,” Dr. Bernick seems to be guaranteed a steady stream of new patients.
“It’s exciting,” he said, “to be in a field that people know so little about.”
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