The relationship between professional boxers and neurodegenerative disease has been well documented. However, a study led by John Hart, Center for Brain Health, School of Behavioural and Brain Sciences, University of Texas at Dallas, USA, published online first in JAMA Neurology, has suggested that it is not only boxers who are at risk of cognitive impairment and depression but all athletes that experience concussion or blows to the head. Therefore, Hart and others aimed to assess cognitive impairment in retired National American Football League (NFL) players using neuroimaging.
The authors stated that traumatic brain injury has been noted as a potential risk factor for neurodegenerative diseases, which includes Alzheimer’s disease. They added: “An association between repeated concussion and mild cognitive impairment and reported memory impairments has also been suggested in retired NFL players.”
The study was comprised of 35 retired NFL players who underwent neurological evaluation. All players reported experiencing concussion ranging from a few seconds of confusion to loss of consciousness for several hours with a range of 1 to 13 concussions in their lifespan.
Twenty six healthy controls without a history of playing collegiate or professional American football and who had not experienced a concussion also underwent neuroimaging. The controls were then matched with the NFL players in terms of age, educational background and estimated IQ in order to compare cognitive results.
According to the results, the authors found that, out of the 35 NFL players, 20 (of which five were depressed without cognitive impairment) were cognitively normal (59%), four were diagnosed as having fixed cognitive deficit (12%), eight were diagnosed as having mild cognitive impairment, and two had dementia.
Hart et al also stated that out of the 35 participants, eight (24%) were diagnosed as having depression. Six participants were without previous diagnosis or treatment for depression. The authors noted that three out of the eight participants with depression had concurrent cognitive deficits that were not entirely associated with depression.
“These findings underscore the need for screening for depression and cognitive dysfunction in retired athletes,” said Hart and et al.
“If confirmed, the findings of studies such as these would support the used of magnetic resonance imaging, particularly diffusion tensor imaging, for monitoring the cumulative burden of concussions in athletes and others who have experienced multiple mild traumatic brain injuries,” said Ramon Diaz-Arrastia and Daniel Perl in an accompanying editorial.