Claims have been made that repeated head impacts occurring in contact sports such as soccer, rugby, and boxing should be formally considered as a cause of dementia. Researchers have presented evidence that Chronic Traumatic Encephalopathy (CTE) may be directly associated with dementia and cognitive decline.
A research team from Boston University in the United States recently analyzed data from 614 brain donors exposed to repetitive head trauma, published in the international journal 《Alzheimer's & Dementia》 in a paper titled (CTE neuropathology alone is associated with dementia and cognitive symptoms). Among them, 366 donors were confirmed to have CTE through autopsy, while 248 were not confirmed. Cases where other major degenerative brain diseases, such as Alzheimer's disease, were identified during autopsy were excluded from the analysis.
The analysis revealed that individuals diagnosed with the most severe stage, CTE stage 4, were approximately 4.5 times more likely to suffer from dementia compared to those without CTE. Even at stage 3 of CTE, the risk of dementia increased by more than two times. The researchers confirmed that dementia and cognitive symptoms could be explained solely by CTE pathological findings. In contrast, no clear association with dementia was found in early-stage (stages 1 and 2) CTE.
Professor Michael Alosco, the lead author of the study (neurology), stated, "This research provides evidence that CTE could be a potential cause of dementia," and added, "Establishing that cognitive decline and dementia are consequences of CTE is an important advancement in developing methods to diagnose CTE while individuals are still alive."
This result is intertwined with ongoing legal disputes in the soccer world. Former players and their families have filed lawsuits against soccer authorities, claiming they failed to adequately protect players from the risks of brain damage due to repeated heading.
According to reports from the BBC and others on the 28th, in relation to the death of former Scotland national team defender Gordon McQueen, the coroner concluded that "repeated heading during soccer matches contributed to brain damage, which may be related to CTE." McQueen had been diagnosed with vascular dementia and CTE during his lifetime and passed away from pneumonia at the age of 70 in June 2023.
Several famous soccer players, including members of England's 1966 World Cup-winning team such as Nobby Stiles, Bobby Charlton, Ray Wilson, and Martin Peters, are also reported to have been diagnosed with dementia before their deaths.
CTE is a disease characterized by the abnormal accumulation of tau protein in the brain, showing pathological findings similar to Alzheimer's disease, but with different patterns of damage. The researchers pointed out that due to these differences, CTE is often misdiagnosed as Alzheimer's disease or other dementias during a person's lifetime.
In fact, among the 186 donors who had been diagnosed with dementia during their lifetime in this study, 40% had been diagnosed with Alzheimer's disease, but no evidence of Alzheimer's was found during autopsy, and 38% were diagnosed with unspecified causes of dementia.
Symptoms related to CTE may gradually appear long after repeated head impacts. Major reported symptoms include memory decline, confusion, and decreased planning and organizational abilities. Some patients may also experience gait disturbances or decreased motor function.
Professor Alosco emphasized, "While some view CTE as a relatively mild disease, this differs from the actual experiences of patients and their families," and stated, "This study shows that CTE can have a significant impact on life, and there is an urgent need to develop diagnostic methods that can distinguish it from other dementias such as Alzheimer's disease."
[Frequently Asked Questions]
Q1. Is CTE the same disease as Alzheimer's disease?
A. No, CTE and Alzheimer's disease are both characterized by tau protein accumulation, but they differ in patterns of damage and causes. CTE is associated with repetitive head impacts and shows different pathological patterns than Alzheimer's disease.
Q2. Does repeated heading actually increase the risk of dementia?
A. According to this study, when CTE caused by repeated head impacts reaches advanced stages (stages 3 and 4), the risk of dementia and cognitive decline significantly increases. In particular, at stage 4 CTE, the likelihood of accompanying dementia is about 4.5 times higher.
Q3. Can CTE be diagnosed while a person is alive?
A. Currently, definitive diagnosis of CTE is primarily made through autopsy. However, the researchers emphasize the need for developing diagnostic methods by revealing that CTE may be a cause of dementia.
