Chronic Traumatic Encephalopathy


Chronic traumatic encephalopathy (CTE) is a progressive neurodegenerative disease in individuals with a history of multiple concussions or other forms of repetitive brain injury. A definite diagnosis can only be made post‐mortem and it is unclear why some individuals appear more susceptible to progressive neurological symptoms following repetitive brain injury than others. CTE has become a major concern in individuals exposed to increased risk of concussion, for example, sports athletes and some military personnel, but its prevalence in such risk groups is unknown. The condition shares some molecular pathologies with other neurodegenerative disorders and it appears that repetitive concussion can initiate a degenerative process involving protein misfolding that may propagate over the brain many years after the trauma. Clinical manifestations of CTE include a wide range of neurological and psychiatric symptoms. These should be treated but presently there is no disease‐modifying therapy against CTE. In contrast to most other neurodegenerative diseases, the condition is preventable.

Key Concepts

  • Chronic traumatic encephalopathy (CTE) may develop secondary to repetitive mild traumatic brain injuries.
  • A definite diagnosis of CTE can only be made post‐mortem.
  • CTE can be prevented but not cured – prevention and symptomatic treatment are important.
  • Brain changes in CTE should be possible to detect and monitor using biomarkers.
  • It is important to study risk factors for CTE – why do some individuals appear to be more susceptible to chronic and sometimes progressive symptoms following traumatic brain injury than others?

Keywords: chronic traumatic encephalopathy; traumatic brain injury; diffuse axonal injury; concussion; biomarkers; neuropathology; tau; amyloid; contact sports

Figure 1. Schematic representation of the neuropathological events involved in concussion and chronic traumatic encephalopathy (CTE). The most important pathogenic event in concussion is diffuse axonal injury secondary to rapid rotational forces on the brain tissue. Repeated concussions result in new neuropathological cascades that eventually may initiate self‐propagating tau pathology and full‐blown CTE.


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Further Reading

Lancet Editorial (2013) Concussion in sport: fair play for young people. Lancet 382: 1536.

Omalu B (2014) Chronic traumatic encephalopathy. Progress in Neurological Surgery 28: 38–49.

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Zetterberg, Henrik(Jan 2015) Chronic Traumatic Encephalopathy. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0025819]