Development of Chronic Traumatic Encephalopathy in Athletes after Repetitive Head Injury

Abstract

Introduction : Chronic traumatic encephalopathy is a state presenting with cognitive, behavioral, or motor abnormalities in athletes, especially within the boxing community and used to be referred to by various terms, such as `punch drunk,` `goofy,` and `slug-nutty`. Later, a more formal term was introduced bearing more medical validity - dementia pugilistica . By the end of the XX century it was concluded that this form of neurodegenerative disease was in fact similar to and yet different from other cases of neurodegeneration. As more evidence came forward about this condition a term coined by Miller became most widely used - chronic traumatic encephalopathy (CTE). The issue received more attention thanks to Omalu`s research. Materials and Methods : This review summarizes data from recent studies, findings and records in the literature on sport-related concussion in a significant number of cases of neuropathologically verified CTE and the detailed findings of CTE in 3 professional athletes, 1 football player and 2 boxers. Results : The clinical picture of CTE is associated with behavioral and personality changes, loss of attention and concentration, short-term memory loss, parkinsonism, and speech and gait abnormalities. Microscopically, CTE can be described as a tauopathy with preferential involvement of the superficial cortical layers, irregular patchy distribution in the frontal and temporal cortices, propensity for sulcal depths, prominent perivascular, periventricular, and subpial distribution, and marked accumulation of tau-immunoreactive astrocytes. Deposition of A-amyloid, most commonly as diffuse plaques, occurs in fewer than half of the cases. Conclusion : Chronic traumatic encephalopathy is a neuropathologically distinct slowly progressive tauopathy with a clear environmental etiology which suggests a significant public health risk for persons who suffer repetitive mild traumatic brain injuries (TBIs). Early identification and prevention of this disease has become a critical focus of current studies.