Concussions promote dementia in gridders.

Repeated concussions brought on by blows to the head during their playing days significantly boost the chances that retired professional football players will suffer dementias such as mild cognitive impairment in later life, suggests a study by the University of North Carolina, Chapel Hill. It also found that ex-National Football League players faced a 37% higher risk of Alzheimer's disease than other U.S. males of the same age.

"In this unique study, we had some very interesting findings," notes Kevin M. Guskiewicz, professor of exercise and sport science. "Our data suggests that a history of recurrent concussions and probably subconcussive contacts to the head may be risk factors for the expression of late-life memory impairment, mild cognitive impairment, and earlier expression of Alzheimer's disease. Research like this is important since more than 300,000 sport-related concussions, many of which are recurrent injuries, occur annually in the U.S. and more than 1,200,000 Americans suffer head injury each year."

Researchers surveyed players aged 50 and older and asked detailed questions about concussions and diagnosed dementia-related impairments. Spouses and close relatives also participated and assisted in confirming responses provided by the retired players.

"When considering prevalence of previous concussions, 60.8% of the retired players reported having sustained at least one concussion during their professional playing career, and 24% reported sustaining three or more concussions," Guskiewicz points out.

Among retired players who sustained a concussion during their professional careers, more than half report experiencing loss of consciousness or memory loss from at least one of their traumas. "We asked the retired players for their subjective assessment of the long-term consequences of their injuries," Guskiewicz explains. "Of the retirees who sustained at least one concussion, 17.6% reported that they perceived the injury to have had a permanent effect on their thinking and memory skills as they have gotten older. The findings showing a relationship between diagnosed mild cognitive impairment and history of concussions--three or more--suggest that a true memory effect is present."

Retired players with three or more concussions had a fivefold greater chance of having been diagnosed with mild cognitive impairment and a threefold prevalence of reported significant memory problems compared to those players without a history of concussion.