Sports-related Concussions & Chronic Traumatic Encephalopathy - Literature review Example

SPORTS RELATED CONCUSSIONS AND CHRONIC TRAUMATIC ENCEPHALOPATHY One cannot talk about entertainment without talking about professional sports. From football to boxing to swimming, there is always a thrilling feeling that engulfs both the players and the audience, but less attention is accorded to the injuries encountered by the players during the games. These injuries are normally sidelined for a long duration of time before recognizable effects are evident. Head concussions are a common injury especially for contact sports like football and boxing. Extensive research has been carried out to elucidate a possible relationship between sport related concussion and chronic traumatic encephalopathy (CTE). This paper seeks to review these studies aimed at determining the linkage between the two conditions. Early studies examined boxing injuries that affected vital body parts including periorbital regions, the brain and kidneys (McCrown, 1959). Despite the gravity of the injuries, most physicians and sports authorities paid little attention to the issue. CTE complications were erroneously referred to as ‘punch drunk syndrome’. McCrown argued against the existence of any neurological syndromes experienced by boxers upon engaging in the sport. He concluded that CTE was only a medical cliché used as a scapegoat for non-performing boxers. Wright (1965) later questioned the delayed onset of the symptoms of CTE due to boxing and concluded that the symptoms could have resulted from other condition that the boxers faced including alcoholism as well as venereal diseases. Latter literature identified basic neurological signs related to boxing: cerebellar, pyramidal and extra-pyramidal signs. Gradual social decline and excessive aggressiveness also occurred (Robert, 1969). Corsellis et al (1973) further described neuropathological signs that determine Parkinson’s disease (PD) – based on the narratives of close relations of 15 retired boxers – as abnormalities of the septum pellucidum and vertical separation of the membranes in the lateral ventricles. Another important aspect in this regard were the risk factors that contribute to CTE due to sporting activities (Loosemore, 2007). Boxers engaged in the profession for more than ten years, those with a history of regular technical knock-outs, and the occurrence of APOE e4 allele in the genetic system were found to be the most vulnerable. In an extensive study, boxing injuries experienced by professional players over a period of 16 years were quantified (Zazryn et al 2003). The state of these injuries and their distribution was highlighted based on database records of 427 fights carried out by the participants. Head and face injuries were the most commonly injured areas (89.7%) followed by the upper limb (2.4%). Nearly all the participants had encountered a head injury during their games. Injuries caused by concussions were second common occurrence (18%) in comparison to other injuries like bruises and inflammation. The research indicated the difference in the type and pattern of injury based on the player’s experience. There is need to examine the mechanism of injury, the prognosis and possible remedies to the problem apart from protective wear. In a study on concussions recognition by its sufferers drawn from Canadian footballers in the 1997 league, 44.8% of the players showed symptoms defining head concussions (Delarey,2000). However, only a few of them (18.8%) recognized these symptoms even though a good number had experienced concussion more than once (69.6%). Delarey’s examination and characterization of concussion indicated a (13%) chance of players experiencing a concussion with every game they played. The relationship between a head injury previously experienced by retired professional players and the development of neurological signs like Alzheimer’s disease (AD) or mild cognitive impairment (MCI) has been established (Guskiewicsz et al. 2005). A cross tabulation was done on the findings from a general health questionnaire with an average of 53.8 years and 6 years of the sport (n=2552) and another questionnaire on memory and cognitive issues (n= 758) . The number of concussions sustained by the players ranged from one (61%) to three (24%). Furthermore, an experience of three or more concussions increased the prevalence of MCI by five-fold and memory issue by three-fold. This research indicated a clear association between recurrent episodes of concussions and diagnosis of MCI and memory issues. However, the occurrence or AD among retirees was not linked to the sporting related concussions. Omalu and others did another study that supported the findings of the previous study in 2006. This was based on an autopsy carried out on a retired professional footballer after 12 years of professional play found the actual cause of death to be coronary atherosclerosis. Based on the head traumas only encountered during football and his symptoms including Parkinson’s disease and mood disorder, a post-mortem study was conducted to determine the occurrence of CTE. The examination revealed evidence mild pallor of the substantia nigra, sparse neurofibrillary tangles. Lack of hemorrhagic infarcts or lewy bodies led to the conclusion that recurrent mild head traumas were a plausible cause of long-term neurological disorders or outcomes. The assessment of the extent of the pathological conditions based on the duration of years of playing was an important recommendation for future studies. Another review done in 2013 was aimed at the identification of CTE disorder and the fact that low cerebral reserve was a leading cause of early clinical diagnosis of neurodegenerative disorders related to age like AD. The study done on a total of 513 retired professional players revealed a level of 35.1% representing cognitive impairment. Comparison of the results with those of patients from a clinic diagnosed with MCI resultant of AD showed a similar profile of cognitive impairment. The research gave an indication of a related increased occurrence of age-related cognitive impairment especially in retired footballers reflected by reduced cerebral reserve (Stella &Randolph, 2013). Modern CTE study on retired athletes to determine the evidence to the assertion of neurodegenerative disorders linked to multiple concussions encountered during football participation. Post mortem examination determined the existence of CTE on professional footballers. However, there is are epidemiological reports of possible overestimation of CTE on these patients as encountered among Canadian players who had multiple concussions but the absence of CTE as a neuro symptom. Based on such findings, there is a need to distinguish the parallel distinction between the history of the concept of CTE and the modernized descriptive term of CTE. This demands caution when one is diagnozing CTE in patients with a history of professional sporting activities (Stella &Randolph, 2013). Mariana et al (2014), carried out a review of animal models to study injuries linked to sporting activities. Mild traumatic brain injury was considered to be more severe than other injuries since it leaves most players struggling with neurological defects including mood disorders and cognitive impairment. The use of animal models in the research was essential in understanding the response of the central nervous system upon injury. It was would bridge the gap between the clinical situation and the pre- clinical research. Momentum exchange and weight drop are some of the methods used to inflict head injury to the animal models. The animal models used in the study could recapitulate an average of 1-2 head impacts. It was also noted that this average number severely injured mature animals. Thus, the impact was described to be more severe in adolescent and young animals given that their brains were still developing during this period. The research indicated the severity of the neurological effects to escalate with a higher number of head injuries including concussions experienced by an individual. The research was limited by failure to identify the number of head impacts on animal models that mimic the same effect towards human athletes. The diminished cerebral reserve hypothesis theoretically attempts to elucidate for the incidence of CTE among professionals in contact sports (Random & Kirkwood, 2009). It posits that repetitive head trauma can diminish cerebral reserve and hence account for occurrence of neurodegenerative conditions like AD and PD. Also hypothesized is the possibility of multiple concussions is an evidence of continued diminishing cerebral reserve. Diminished reserve is a neurodegenerative diseases’ predictor .this implies a retired boxer or footballer is more likely to suffer from the early manifestation of MCI than the general public. The hypothesis also distinguishes nueropathological changes associated with CTE from pathologies related to other conditions like PD, MCI or AD. Evidence discussed in this paper validates, to a considerable extent, the predictive aspect of this hypothesis. From the foregoing, the relationship between CTE and sport-related concussions is empirically evident and theoretically plausible. The analysis of the study can be a difficult task especially when the people at risks are unable to define and carry out a self-report of a concussion they have suffered. Extensive health education of the players on the symptoms and long-term effects of the condition should be a mandatory activity in every professional game. Addressing the sport-related concussions at an early stage will save the players a lifetime of neurological issues like CTE. Professional players should consider their lives being more valuable than the profession as neurological conditions have been shown to escalate with multiple concussions. Meticulous diagnosis of CTE especially for retired professional players is highly recommended. Sport-related concussions should, however, not be damned as the cause of all types of neurodegenerative diseases. Age also features as an important factor in the occurrence of these symptoms; thus, retired players will be of more concern during such examination compared to young and adolescent players. REFERENCES Randolph, C., Karantzoulis, S., &Guskiewicz, K. (2013). Prevalence and characterization of mild cognitive impairment in retired national football league players. Journal of the International Neuropsychological Society. 19. p.873-880. McCrown, I.A. (1959). Boxing Injuries. American Journal of Surgery. 98(3). p.509-516. Corsellis, J.A, Bruton, C.J, & Freeman-Browne D. (1973). The Aftermath of Boxing. Psychological Medicine. 3(3). p.270-303. Roberts, A.H. (1969). Brain Damage in Boxers – A Study of the Prevalence of Traumatic Encephalopathy among Ex Professional Boxers. London:Pitman. Loosemore, M. Knowles, C. Whyte, G.P. (2007). Amateur Boxing and Risk of Chronic Traumatic Brain Injury. Systemic Review on Observational Studies. British Medical Journal. 335(7624). p.809. Zazryn, T.R, Finch, C.F, &McCrory, P. (2003). A 16 year study of injuries to professional boxers in the state of Victoria, Australia.Br J Sports Medicine. 37. p. 321–324. Mariana, A, Michael, J. K, Denise, I. B, Nieves, H, David, C.V. &Donald, M. K. (2014) Animal models of sports-related head injury: bridging the gap between pre-clinical research and clinical reality. Journal of Neurochemistry, 129(6).p.916–931. Delaney, J. S, Lacroix, V. J, Leclerc, S. &Johnston, K. (2000). Concussions During the 1997 Canadian Football League Season. Clinical Journal of Sport Medicine. 10(1).p.9-14. Omalu, B. I, DeKosky, S. T, Ryan, L., Kamboh, M.I, Hamilton, R. L, Wecht, C. H. (2006). Chronic Traumatic Encephalopathy in a National Football League Player.Neurosurgery.57 (1).p.128–134. Randolph, C., & Kirkwood, M.W. (2009). What are the real risks of sport-related concussion, and are they modifiable? Journal of the International Neuropsychological Society, 15, 512–520. Stella K., &Randolph C. (2013). Modern Chronic Traumatic Encephalopathy in Retired Athletes: What is the Evidence?Neuropsychology Review. 23(4).p 350-360. Read More

In an extensive study, boxing injuries experienced by professional players over a period of 16 years were quantified (Zazryn et al 2003). The state of these injuries and their distribution was highlighted based on database records of 427 fights carried out by the participants. Head and face injuries were the most commonly injured areas (89.7%) followed by the upper limb (2.4%). Nearly all the participants had encountered a head injury during their games. Injuries caused by concussions were second common occurrence (18%) in comparison to other injuries like bruises and inflammation.

The research indicated the difference in the type and pattern of injury based on the player’s experience. There is need to examine the mechanism of injury, the prognosis and possible remedies to the problem apart from protective wear. In a study on concussions recognition by its sufferers drawn from Canadian footballers in the 1997 league, 44.8% of the players showed symptoms defining head concussions (Delarey,2000). However, only a few of them (18.8%) recognized these symptoms even though a good number had experienced concussion more than once (69.6%). Delarey’s examination and characterization of concussion indicated a (13%) chance of players experiencing a concussion with every game they played.

The relationship between a head injury previously experienced by retired professional players and the development of neurological signs like Alzheimer’s disease (AD) or mild cognitive impairment (MCI) has been established (Guskiewicsz et al. 2005). A cross tabulation was done on the findings from a general health questionnaire with an average of 53.8 years and 6 years of the sport (n=2552) and another questionnaire on memory and cognitive issues (n= 758) . The number of concussions sustained by the players ranged from one (61%) to three (24%).

Furthermore, an experience of three or more concussions increased the prevalence of MCI by five-fold and memory issue by three-fold. This research indicated a clear association between recurrent episodes of concussions and diagnosis of MCI and memory issues. However, the occurrence or AD among retirees was not linked to the sporting related concussions. Omalu and others did another study that supported the findings of the previous study in 2006. This was based on an autopsy carried out on a retired professional footballer after 12 years of professional play found the actual cause of death to be coronary atherosclerosis.

Based on the head traumas only encountered during football and his symptoms including Parkinson’s disease and mood disorder, a post-mortem study was conducted to determine the occurrence of CTE. The examination revealed evidence mild pallor of the substantia nigra, sparse neurofibrillary tangles. Lack of hemorrhagic infarcts or lewy bodies led to the conclusion that recurrent mild head traumas were a plausible cause of long-term neurological disorders or outcomes. The assessment of the extent of the pathological conditions based on the duration of years of playing was an important recommendation for future studies.

Another review done in 2013 was aimed at the identification of CTE disorder and the fact that low cerebral reserve was a leading cause of early clinical diagnosis of neurodegenerative disorders related to age like AD. The study done on a total of 513 retired professional players revealed a level of 35.1% representing cognitive impairment. Comparison of the results with those of patients from a clinic diagnosed with MCI resultant of AD showed a similar profile of cognitive impairment. The research gave an indication of a related increased occurrence of age-related cognitive impairment especially in retired footballers reflected by reduced cerebral reserve (Stella &Randolph, 2013).

Modern CTE study on retired athletes to determine the evidence to the assertion of neurodegenerative disorders linked to multiple concussions encountered during football participation. Post mortem examination determined the existence of CTE on professional footballers.

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