Is there chronic
brain damage in retired NFL players? Neurology, neuropsychology, and neurology
examinations of 45 retired players

Casson
IR., Viano DC., Haacke EM.,Kou Z., LeStrange DG. Sports Health 2014;ahead of
print.

Take Home Message: Neuropsychological
impairments were found in some players; however, the majority of retired NFL
players had no clinical signs of chronic brain damage. Some retired players had lesions found on brain imaging
tests and these were associated with the number of previous concussions.

Evidence
of neuropathology in the brains of deceased football players has led to
widespread concern for retired players. Survey studies have suggested that
depression and cognitive problems occur in retired NFL players; however, there
is not much information reported on the neurological, neuropsychological, and neuroradiological
examination of living, retired NFL players. Therefore, the authors performed
clinical neurological, neuropsychological, and neuroroadiological examinations
on 45 living, retired NFL players (on average 46 years of age, 31kg/m2
BMI, 6.8 years of playing experience, and 34 reported 3+ previous concussions).
Participants’ histories focused on neurological and depression symptoms,
exposure to football on-field time, and other factors that could affect the
brain function. A neurological examination followed, which consisted of Mini-Mental State Evaluation, Beck Depression Inventory,
and Patient Health Questionnaire. The neuropsychological portion of the study included
a pen and paper exam created by 5 neuropsychologists and an ImPACT exam. Neuroradiological analyses
consisted of magnetic
resonance imaging
(MRI) utilizing susceptibility weighted imaging and diffusion tensor imaging. Finally, the examination concluded with a blood draw for APOE genotyping and
blood chemistry analysis. Up to nine retired players had moderate to severe depression
depending on which criteria the authors used. Depression scores were not
associated with football exposure. The neuropsychology examination demonstrated
that none of the players had dementia; however, 24% had some memory impairment.
Susceptibility weighted imaging MRI correlated with family history of
neurological disease, and number of “dings” (un-diagnosed concussions) at all
football levels (high school through professional). Four retired players had microbleeds
(detected using the susceptibility weighted imaging MRI) and these may be
associated with number of dings in football career. Seventeen retired players carried
at least one copy of the APOE E4 allele (the allele that has been associated
with onset of Alzheimer’s due to head impact). Diffusion tensor imaging
detected that there was lower fiber density, myelination, and axonal diameter
with participants carrying the APOE E4 allele. Additionally, being “dinged,” while
playing contact sports other than football and previous concussions were also
associated with APOE E4 allele.

This
is an interesting study because it is one of the first studies that performed a
thorough clinical evaluation of retired, living NFL players. It is encouraging
to see that the percentage of participants that demonstrated moderate to severe
depression was in line with the general public (~15-20%). Though, there were no
diagnosed cases of dementia, 24% of retired players showed some memory
impairments and there were abnormalities seen with imaging techniques. Abnormal
imaging were associated with higher number of football concussions no matter
what level of play, which suggests that there needs to be more conservative
management of football players with previous concussion history. Finally, 34%
of the participants carried the APOE E4 allele, which is higher than the
general population (~24%). This is important because this genetic variation is
associated with the onset of Alzheimer’s. While many have been quick to
criticize football because of the risk for long-term neurocognitive impairment.
This study reminds us that many football players may have normal long-term
neurocognitive health. Much like with the risk of sudden cardiac death in
sports we need to strive to identify better ways of recognize which athletes
may be susceptible to neurocognitive impairments (for example, testing for APOE
E4 genetic variations).  Alternatively,
we can adopt the approach that we are using to protect long-term joint health
by exploring new injury prevention programs but with a concussion focus.

Questions for Discussion:
Should sports medicine clinicians provide care for retired athletes? How often
should retired athletes, like NFL players, receive examinations? Should extra
care only be given to NFL athletes with documented concussions?

Written
by: Jane McDevitt, PhD
Reviewed
by: Jeff Driban

Related
Posts:

Casson, I., Viano, D., Haacke, E., Kou, Z., & LeStrange, D. (2014). Is There Chronic Brain Damage in Retired NFL Players? Neuroradiology, Neuropsychology, and Neurology Examinations of 45 Retired Players Sports Health: A Multidisciplinary Approach DOI: 10.1177/1941738114540270