ARTICLE IN BRIEF
Sports neurology experts discuss efforts to develop new guidelines on sports-related concussion following an NFL-commissioned survey in which retired players reported more memory loss problems than those in the general population.
An National Football League (NFL)-commissioned survey of former professional football players — conducted by investigators at the Institute for Social Research at the University of Michigan — found that those under 50 were almost 20 times more likely to report memory problems than would be expected in the general population.
The survey was released in October and made headlines in the sports pages of most major papers, raising the question: Would the NFL then agree to compensate its players for medical problems related to memory loss?
The issue is far from resolved, and according to experts in sports neurology, the associated link between head injury and memory loss requires further (and more well-designed prospective) studies.
While the NFL study was not designed to determine a causal link between repeated blows to the head and dementia — no one was actually examined — neurologists agree that it is critical to know the long-term risks of repeated head injuries.
“I think it is essential that we do the appropriate scientific studies and do them as quickly as possible,” said Jeffrey S. Kutcher, MD, director of Michigan NeuroSport at the University of Michigan and chair of the AAN Sports Neurology Section.
CONCERNS ABOUT STUDY DESIGN
Dr. Kutcher had no involvement in the survey that was conducted by David Weir, PhD, and his colleagues at the Institute for Social Research. The NFL study looked at a range of health measures in 1,063 former NFL players. But experts said the survey design was problematic.
According to Dr. Kutcher, there was only one question on memory problems in the study: “Do you have a diagnosis from a physician of Alzheimer disease, dementia, or memory-related disease?” — and there was no way to discern the background of complaints that led to that diagnosis. A long list of medical complaints, including pain syndromes, depression, and sleep disorders, could impair memory and many of those surveyed reported multiple medical concerns.
The survey results come at the same time that the AAN Sports Neurology Section is launching a listserv to pull experts in the field together to discuss issues such as sports concussion. The AAN guidelines were published initially in 1997.
“In the interim, our understanding of concussion has changed,” said Dr. Kutcher. “The main thing that we now know from clinical experience is that how an athlete presents immediately after a concussion does not allow us to predict the course [of the injury]. Therefore, attempting to classify a concussion for the purpose of determining the management of the patient is not possible.”
The NFL-sponsored survey was conducted by phone and designed to address a long list of health and lifestyle factors among retired NFL players, including marriage, heart disease, cancer, diabetes, migraines, neck pain, depression, and memory problems. When they separated the group by age, the scientists found that 2 percent of those under 50 and 6 percent of those older than 50 said that they had been diagnosed with a memory disorder. But as Dr. Kutcher pointed out, 75 percent of those surveyed also answered “yes” to at least one question on depression and 17 percent said they had been diagnosed with sleep apnea. “These data provide us with a portrait based on self reporting. The study was not intended to be diagnostic.”
In October, Dr. Weir told members of a Congressional hearing on sports-related concussion: “The study was not designed to diagnose or assess dementia. The study did not conclude that football causes dementia.”
“We need to really understand this link,” said Dr. Kutcher. “The survey results reconfirmed suspicions that a lifetime of multiple mild brain injuries can lead to cognitive problems.”
The portrait of these men also suggests that they have a three-fold higher incidence of cancer. Dr. Kutcher, an expert on sports-related injuries, suggested that the data might be biased toward reporting more medical problems because the men knew the study was commissioned by the NFL.
The neurologist has also spoken by phone in recent weeks with Dr. Weir and NFL officials to discuss the next steps.
Anthony Alessi, MD, a neurologist in Norwich, CT, who also co-chairs the AAN Sports Neurology Section, said that the NFL “wants to work with the AAN study section to figure out the best way to study this link between multiple concussions and dementia.”
Dr. Alessi spent his career evaluating and treating boxers with traumatic encephalopathy. “Boxing is the paradigm for these studies,” he said. “Do memory problems come on sooner? If yes, then when do we intervene and how?”
Dr. Alessi thinks that the rules surrounding football may need to change. He said that football players in high school, even younger, are not offered the protections that major league players have, including the proper trainers who know when a player has experienced concussion and should be removed from the game or when it is safe to allow them back in the game.
“We are now trying to get our neurological community to take the lead on these issues,” Dr. Alessi said. The sports injury section has a listserv that includes an active roster of 300 doctors.
He added that it is probably good medicine to have football players and boxers go through an annual evaluation to detect early signs of neurological problems. Previous autopsy studies of brain tissue culled from former football players have reportedly shown pathological changes consistent with a trauma induced dementing process.
Indeed, the NFL is listening to the new science on sports-related concussion. The league has just implemented a new policy that requires an independent neurologist to examine a player on the heels of a concussion. The AAN has offered to help with such efforts and create guidelines on when someone should be removed from the game and allowed to return to the field.
Meanwhile, NFL Commissioner Roger Goodell provided written testimony to the House Judiciary Committee that the league will offer a free diagnostic or medical work-up to those former players who said that they have dementia.