This week from Dr. Cerami and Utah Sports and Wellness
From: Acta Neuropathology, March 2017
These authors followed 14 retired soccer players with dementia regularly for 30 years until their deaths. All were skilled headers of the ball and had played soccer for an average of 26 years. Six of these players had a history of concussion, one each. This study found that all cases developed progressive cognitive impairment. It was discovered that, retired soccer player with a past history of repetitive head impacts may have an increased risk of chronic traumatic encephalopathy (CTE), resulting in dementia and motor impairments. An average player heads the ball 6-12 times per game and performs at least 2,000 headers during a 20-year career, in addition to repetitive drills at training.
In retired professional association football (soccer) players with a past history of repetitive head impacts, chronic traumatic encephalopathy (CTE) is a potential neurodegenerative cause of dementia and motor impairments. From 1980 to 2010, 14 retired footballers with dementia were followed up regularly until death. Their clinical data, playing career, and concussion history were prospectively collected. Next-of-kin provided consent for six to have post-mortem brain examination. Of the 14 male participants, 13 were professional and 1 was a committed amateur. All were skilled headers of the ball and had played football for an average of 26 years. Concussion rate was limited in six cases to one episode each during their careers. All cases developed progressive cognitive impairment with an average age at onset of 63.6 years and disease duration of 10 years. Neuropathological examination revealed septal abnormalities in all six post-mortem cases, supportive of a history of chronic repetitive head impacts. Four cases had pathologically confirmed CTE; concomitant pathologies included Alzheimer’s disease (N = 6), TDP-43 (N = 6), cerebral amyloid angiopathy (N = 5), hippocampal sclerosis (N = 2), corticobasal degeneration (N = 1), dementia with Lewy bodies (N = 1), and vascular pathology (N = 1); and all would have contributed synergistically to the clinical manifestations. The pathological diagnosis of CTE was established in four individuals according to the latest consensus diagnostic criteria. This finding is probably related to their past prolonged exposure to repetitive head impacts from head-to-player collisions and heading the ball thousands of time throughout their careers. Alzheimer’s disease and TDP-43 pathologies are common concomitant findings in CTE, both of which are increasingly considered as part of the CTE pathological entity in older individuals. Association football is the most popular sport in the world and the potential link between repetitive head impacts from playing football and CTE as indicated from our findings is of considerable public health interest. Clearly, a definitive link cannot be established in this clinico-pathological series, but our findings support the need for further systematic investigation, including large-scale case-control studies to identify at risk groups of footballers which will justify for the implementation of protective strategies.
These authors also note:
- The long-term neurodegenerative consequence of repetitive mild traumatic brain injury (rTBI) was originally termed “punch drunk syndrome” in boxers; it is now known as chronic traumatic encephalopathy (CTE).
- “The clinical features of CTE are variable and consist of a combination of mood and behavioural changes, memory loss, executive dysfunction, slurred
speech, Parkinsonism, and gait impairment, which typically manifest years after the initial rTBI.”
- At present, CTE diagnosis “can only be confirmed by neuropathological examination.”
- “Head injuries in football [soccer] are nevertheless more frequently caused by head-player contact (40%) than head-ball contact (12.6%).”
- “Many head impacts in football [soccer] do not result in concussion and overt neurological symptoms, yet are associated with subtle neuropsychiatric
deficits or changes in functional MRI, and are referred as ‘subconcussion’.”
- “Brain structural and cognitive changes have been reported in footballers exposed to repetitive subconcussive head impacts including heading.”
- Dementia is a potential late life consequence of playing professional football [soccer]. Four of the eight surviving footballers in the 1966 England’s World Cup winning team have dementia.
In this study:
• 12/14 cases died from advanced neurodegenerative disease.
• 12/14 cases had at least one CT or MR imaging of the brain following the
onset of their neurological symptoms, and cortical atrophy was a consistent finding.
• All cases demonstrated some features supportive of CTE, including
characteristic tau pathologies, dilatation of third ventricle, and septal abnormalities.
• All cases had concomitant Alzheimer’s Disease pathology.
- “We hypothesize that CTE and, probably, AD and TDP-43 [pathological brain protein found in dementia] pathologies in these retired footballers are related to their past prolonged exposure to repetitive subconcussive head impacts from heading and head-to-player collisions.”
- In this series, the “CTE findings is probably related to their past prolonged exposure to repetitive head impacts from head-to-player collisions and heading the ball thousands of time throughout their careers.”
- The notion that prolonged exposure to repetitive subconcussive head impacts can lead to CTE is supported by other studies.
“Football [soccer] is the most popular sport worldwide with over 250 million players at all levels. Although this study does not provide a firm causal relationship between CTE and exposure to repetitive head impacts from playing football, our findings support the pressing need to instigating large-scale studies to identify at risk groups of footballers, including age of exposure, which will justify for the implementation of protective strategies and education of current players.”