Chronic traumatic encephalopathy neuropathologic change is uncommon in men who played amateur American football

Iverson GL, Jamshidi P, Fisher-Hubbard AO, Deep-Soboslay A, Hyde TM, Kleinman JE, deJong JL, Shepherd CE, Hazrati LN, Castellani RJ. Front Neurol. 2023 Jun 19;14:1143882. doi: 10.3389/fneur.2023.1143882. PMID: 37404944; PMCID: PMC10315537.

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Take-Home Message

Among brain tissue from men over 50, none had definitive chronic traumatic encephalopathy (CTE) neuropathologic change. However, three or more authors found that 5% of brains had “features” of CTE neuropathologic change, which came from cases with and without a history of playing collision sports.


Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease, which can only be diagnosed after death. Recently, there was an update on how to define cases. Instead of a blanket absence or presence, screeners can note the level of components or “features” of CTE neuropathic change.

Study Goal

The authors evaluated brain tissue from the Lieber Institute for Brain Development Tissue Bank to examine CTE neuropathologic changes in relation to a history of American football youth participation and suicide as a manner of death.


The authors assessed 186 donated brains from men in a tissue bank enriched with samples from people with neuropsychiatric problems and suicide(~66 years of age; 58 participated in a contact sport, 67 died by suicide). Two authors screened the brains. Then five authors examined the selected brains for signs of CTE using the 2016 and 2021 consensus definitions. The authors also evaluated clinical documents and interviewed next of kin to ascertain their medical, social, demographic, family, and psychiatric history. Additionally, they considered their history of head/brain trauma/injury and personal history of participation and concussions in sports.


No brain definitively met the criteria for CTE neuropathic change based on the 2016 or 2021 definition. Furthermore, the five authors never unanimously agreed on a case having “features” of CTE neuropathic changes. However, three or more authors found 10 cases (5.4%) with “features” of one or both definitions for CTE neuropathic change.

The authors found no differences between CTE neuropathic change and personal history of playing American football or contact sports (contact sports = 9%, no contact sports = 4%). Additionally, there was no difference between CTE neuropathic change tissue samples and those with a history of brain injury (brain injury  = 4%, no brain injury = 6%), mood disorder (mood disorder = 6%, no mood disorder = 6.0%), or manner of death (suicide = 6%, not suicide = 5%).


Overall, no definitive case of CTE was identified in this sample. Some authors found “features” of CTE neuropathic changes in 1 in 20 brains. Therefore, this condition was very uncommon in men who played amateur football, those with mood disorders during life, and those with suicide as a manner of death. One of the notable strengths of this study was that the authors utilized a different brain bank, where the focus surrounding the brain tissue donations was regarding psychiatric conditions and not contact sports history. The findings in this bank were in line with the low rates in other banks, such as 4% of cases in military brain tissue bank. However, these previous banks do not represent the general population. It remains unclear how common CTE and “features” of CTE neuropathic changes are in the general population. This is vital to understanding how common CTE is in society and accurately assessing who is at risk for CTE and the “features” of CTE.

Clinical Implications

Medical professionals can reassure people that despite recent media attention, the prevalence of CTE and its features are relatively small. With that being said, we should educate our stakeholders (e.g., parents, patients) that the level of evidence in this area is weak and there is much for us to learn. Clinicians should encourage positive brain health by limiting repetitive head impacts by improving rules and regulations in contact sports and limiting contact during practices.

Questions for Discussion

Do you believe there would be an increased risk of CTE pathology in those who had a history of playing contact sports or had a history of repeated brain injuries? How do you educate your patients regarding CTE?

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  3. When it Comes to Chronic Traumatic Encephalopathy (CTE): Perhaps Mother Doesn’t Know Best
  4. Could Playing Contact Sports in High School and College Increase Risk of CTE?
  5. Disconnect Between Concussion Education and CTE
  6. Most Military Members May Not Need to Worry About CTE

Written by Jane McDevitt
Reviewed by Jeffrey Driban

Evidence-Based Assessment of Concussion Course - 5 EBP CEUs