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Absence of chronic traumatic encephalopathy in retired football players with multiple concussions and neurological symptomatology
Open accessAbstract
BACKGROUND: Chronic traumatic encephalopathy (CTE) is the term coined for the neurodegenerative disease often suspected in athletes with histories of repeated concussion and progressive dementia. Histologically, CTE is defined as a tauopathy with a distribution of tau-positive neurofibrillary tangles (NFTs) that is distinct from other tauopathies, and usually shows an absence of beta-amyloid deposits, in contrast to Alzheimer's disease (AD). Although the connection between repeated concussions and CTE-type neurodegeneration has been recently proposed, this causal relationship has not yet been firmly established. Also, the prevalence of CTE among athletes with multiple concussions is unknown. METHODS: We performed a consecutive case series brain autopsy study on six retired professional football players from the Canadian Football League (CFL) with histories of multiple concussions and significant neurological decline. RESULTS: All participants had progressive neurocognitive decline prior to death; however, only 3 cases had post-mortem neuropathological findings consistent with CTE. The other 3 participants had pathological diagnoses of AD, amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD). Moreover, the CTE cases showed co-morbid pathology of cancer, vascular disease, and AD. DISCUSSION: Our case studies highlight that not all athletes with history of repeated concussions and neurological symptomology present neuropathological changes of CTE. These preliminary findings support the need for further research into the link between concussion and CTE as well as the need to expand the research to other possible causes of taupathy in athletes. They point to a critical need for prospective studies with good sampling methods to allow us to understand the relationship between multiple concussions and the development of CTE.
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In the citing paper
“It is now well established that a large percentage of former athletes identified as having CTE neuropathology also have neuropathology associated with age related neurodegenerative diseases such as AD, PD, Lewy body disease, hippocampal sclerosis, and ALS [14, 41–44] to the extent that they meet full neuropathological criteria for an alternative, well-characterized neurodegenerative disease [16].”
From The Need to Separate Chronic Traumatic Encephalopathy Neuropathology from Clinical Features (2017) · cites this paper as [41]
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“It is also important to note that CTE-consistent pathology has been reported in cases with no history of head trauma, further indicating that it may be a common pathology within the general population and not specific to the aftermath of mTBI [55, 69, 89, 119].”
From DNA repair deficiency and senescence in concussed professional athletes involved in contact sports (2019) · cites this paper as [55]
In the citing paper
“In different autopsy series, the percentage of former professional American football players who have died and donated their brains to research varies from 50 % [88], 80 % [146], to 97 %) [128].”
From The neuropathology of sport (2014) · cites this paper as [88]
In the citing paper
“Although CTE was first identified in association with boxing, CTE has been diagnosed neuropathologically in American football players, professional and amateur boxers, ice hockey players, professional wrestlers, soccer players, rugby players, and a professional baseball player (Figs. 3, 4, 5, 6) [38, 65, 66, 88, 91, 127, 128, 146–148].”
From The neuropathology of sport (2014) · cites this paper as [88]
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Metadata
- Authors
- Hazrati, L.-N., Tartaglia, M. C., Diamandis, P., Davis, K. D., Green, R. E., Wennberg, R., Wong, J. C., Ezerins, L., & Tator, C. H.
- Affiliations
- University of Toronto (CA)
- University Health Network (CA)
- Corresponding author
- Hazrati, Lili-Naz
- ORCID
- Venue
- Frontiers in Human Neuroscience
- Publisher
- Frontiers Media SA
- Published
- 2013
- Volume
- 7
- Pages
- 222-222
- ISSN
- 1662-5161 (ISSN-L)
- PMC
- PMC3662898
- OpenAlex
- W2127938589
- Cited by
- 146
- References
- 27
- Citations by year
- 2026: 1 · 2025: 2 · 2024: 8 · 2023: 7 · 2022: 10 · 2021: 6 · 2020: 7 · 2019: 10 · 2018: 15 · 2017: 16 · 2016: 17 · 2015: 26 · 2014: 13 · 2013: 7
- FWCI
- 15.33
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Licence
- cc-by
- Locations
- Frontiers in Human Neuroscience (publishedVersion, cc-by)
- Europe PMC (PubMed Central) (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- eScholarship@McGill (McGill) (submittedVersion)
- eScholarship@McGill (McGill) (submittedVersion, cc-by)
- Funders
- Physicians' Services Incorporated Foundation
- Topics
- Health Sciences › Medicine › Clinical Neurology › Traumatic Brain Injury Research
- Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Alzheimer's disease research and treatments
- Health Sciences › Medicine › Clinical Neurology › Traumatic Brain Injury and Neurovascular Disturbances
- Keywords
- chronic traumatic encephalopathy, repeated concussions, Canadian Football League, tauopathy, neurofibrillary tangles, Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, postmortem neuropathology, neurocognitive decline
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