A study suggests that 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.
The study, conducted by University of North Carolina at Chapel Hill researchers and colleagues, found that retired National Football League players also faced a 37 percent higher risk of Alzheimers than other U. S. males of the same age.
" In this study, we had some very interesting findings," Guskiewicz said. " Our data suggest that a history of recurrent concussions and probably sub-concussive contacts to the head may be risk factors for the expression of late-life memory impairment, mild cognitive impairment and earlier expression of Alzheimers 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 1.2 million Americans suffer head injury each year."
The study involved surveying by mail 3,683 retired professional football players who belonged to the NFL Retired Players Association about their overall health and analyzing the results.
Of those, 2,552 returned questionnaires or had their spouses or other close relatives do so for about a 70 percent response rate. Players averaged almost 54 years old and had an average professional career spanning 6.6 years.
Researchers then surveyed a subset of 758 players aged 50 and older and asked more 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, 1,513, or 60.8 percent, of the retired players reported having sustained at least one concussion during their professional playing career, and 597, or 24 percent, reported sustaining three or more concussions," Guskiewicz said.
Among retired players who sustained a concussion during their professional careers, more than half reported experiencing loss of consciousness or memory loss from at least one of their concussions, he said.
" We asked the retired players for their subjective assessment of the long-term consequences of their injuries," Guskiewicz said. " Of the retirees who sustained at least one concussion, 266, or 17.6 percent, 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 five-fold greater chance of having been diagnosed with mild cognitive impairment and a three-fold prevalence of reported significant memory problems compared to those players without a history of concussion, he said. Physicians had diagnosed 33 players with Alzheimers. The higher prevalence of the memory-destroying disease was more noticeable in the younger age groups -- those below age 70 than in those over that age.
Source: University of North Carolina at Chapel Hill, 2005