Athletes who get concussions could be in for more than a couple days of headache.
Researchers are discovering that the effects of mild head trauma may not be benign. A recent study into the effects of repeated concussions on former athletes found that deficits in brain function can be apparent as many as 30 or more years after the initial incident.
Researchers, eight physicians from three Canadian institutions, observed a decline in cognitive ability similar to the early stages of dementia in participants who reported having just one or two concussions.
Compared with 21 athletes who had never sustained a concussion, the 19 former hockey and football players, with a mean age of 60, showed decreased thinking and motor skills.
Though the observed impairments were relatively mild and did not prevent the former athletes from leading functionally normal lives, investigators feel the need to perform further tests, said senior author Maryse Lassonde of the University of Montreal.
“We need to follow them up in order to see whether these impairments will become pathological with time,” she said.
For now, observing whether or not patients exhibit more severe mental problems earlier than expected is the only way to determine the effects of an injury, as mild brain damage remains invisible to modern imaging techniques such as the MRI and CT scan.
A typical concussion, caused by excessive force on the brain, causes all of the cells and neurons in the brain to fire, which in turn creates a cascade of chemical changes in the brain related to amnesia, loss of consciousness, anxiety and lethargy.
“These symptoms, called post-concussive syndrome, recover over time,” said Dr. David Hovda, professor of molecular and medical pharmacology and neurology at UCLA. “We used to think it took days or weeks, now we think it may take months.“
Every brain injury is a type of concussion, and the brain becomes particularly vulnerable while in recovery, which increases the likelihood of multiple injuries.
“It is these repeated blows that we think contribute to the long term atrophy of the brain, which has been related to Parkinson’s, Alzheimer’s and dementia,” Hovda said. “As for the mechanism by which these cells die off, we don’t have a good handle on why this happens.“
The causes of this long-term atrophy – and whether or not it may be linked to mild brain injury – are only just beginning to be explored.
A separate study examining the brains of former athletes posthumously, found examples of the much more detrimental brain damage resulting from multiple injuries in the brains of two former athletes.
Released last week by the Center for the Study of Traumatic Encephalopathy at the Boston University School of Medicine, the study strengthens the argument that repeated concussions cause severe, long-term damage to the brain.
The visible effects of multiple concussions were documented by testing tissue from the brain of former NFL player Tom McHale, revealing a great deal of damage.
McHale, the sixth former NFL player whose brain has been studied by CSTE, suffered from what is called chronic traumatic encephalopathy (CTE), a chronic disease state of the brain – evidence of a career filled with head trauma.
More unexpected was the evidence of the beginnings of similar damage found in the brain of a deceased 18-year-old multi-sport athlete by the co-director of the CSTE Ann McKee, a neuropathologist at the Veterans Administration Hospital in Bedford, Mass.
McKee has called the finding “basically unheard of” in such a young individual.
Football-related head injuries accounted for 36,412 visits to U.S. hospital emergency rooms in 2007, or just over 11.5 percent of all sports-related head injuries, according to the U.S. Consumer Product Safety Commission.
The only sport to surpass football was cycling, which accounted for over 20 percent of those injuries.
AARON BRUNER can be reached at firstname.lastname@example.org.