Youth tackle football participation linked to earlier onset of cognitive and emotional symptoms

April 30, 2018

Science Daily/Boston University School of Medicine

Starting to play tackle football before age 12 could lead to earlier onset of cognitive and emotional symptoms among athletes who were diagnosed with CTE and other brain diseases postmortem, according to a new study.

The findings, from researchers at VA Boston Healthcare System (VABHS) and Boston University (BU) School of Medicine, found that among 211 football players who were diagnosed with the neurodegenerative disease CTE after death, those who began tackle football before age 12 had an earlier onset of cognitive, behavior, and mood symptoms by an average of 13 years.

Every one year younger that the individuals began to play tackle football predicted earlier onset of cognitive problems by 2.4 years and behavioral and mood problems by 2.5 years. This study included 246 deceased football players who were part of the UNITE (Understanding Neurologic Injury and Traumatic Encephalopathy) study and who had donated their brains for neuropathological examination to the VA-BU-CLF (Concussion Legacy Foundation) Brain Bank. Of those 246, 211 were diagnosed with CTE (with several having evidence of additional brain diseases, such as Alzheimer's) and 35 had no evidence of CTE, though several had evidence of other neuropathology. Of the 211 with CTE, 76 were amateur football players and 135 played at the professional level.

"Youth exposure to repetitive head impacts in tackle football may reduce one's resiliency to brain diseases later in life, including, but not limited to CTE," said corresponding author Ann McKee, MD, chief of Neuropathology at Boston VA Healthcare System, and Director of BU's CTE Center. "It makes common sense that children, whose brains are rapidly developing, should not be hitting their heads hundreds of times per season."

It is noteworthy that, although age of first exposure to tackle football was associated with early onset of cognitive and emotional problems, it was not associated with worse overall severity of CTE pathology, Alzheimer's disease pathology or other pathology. In addition, earlier symptom onset was not restricted to those diagnosed with CTE. The relationship was similar for the former football players without CTE who had cognitive or behavioral and mood changes that may have been related to other diseases.

"Younger age of first exposure to tackle football appears to increase vulnerability to the effects of CTE and other brain diseases or conditions. That is, it influences when cognitive, behavioral, and mood symptoms begin. It is comparable to research showing that children exposed to neurotoxins (e.g., lead) during critical periods of neurodevelopment can have earlier onset and more severe long-term neurological effects. While participation in sports has important health and social benefits, it is important to consider contact and collision sports separately and balance those benefits against potential later life neurological risks," said Michael Alosco, PhD, an assistant professor of Neurology at BU School of Medicine and an investigator at the BU Alzheimer's Disease Center and the BU CTE Center.

The study extends research from the BU CTE Center that previously linked youth tackle football with worse later-life cognitive, emotional, and behavioral disturbances in living former amateur and professional tackle football players, as well as changes in brain structures (determined by MRI scans) in former NFL players.

Data were collected by conducting telephone interviews with family members and/or friends to determine the absence or presence, and age of onset, of cognitive, behavior and mood symptoms. The interviewers did not know the neuropathological findings and the neuropathologists did not know the individuals' histories.

Although this study supports the idea that there may be long-term consequences associated with experiencing repeated hits to the head during childhood, the researchers stress that it is unclear if their findings generalize to the broader tackle football population and that much more research, particularly prospective longitudinal studies, is needed to understand the association between youth football and long-term consequences. The findings appear online in the journal Annals of Neurology.

https://www.sciencedaily.com/releases/2018/04/180430131950.htm

Call for more research on brain damage in American football

March 24, 2015

Science Daily/BMJ

More research is needed to identify how athletes sustain brain injury from American football, and also to develop strategies to protect them, write experts. Chronic traumatic encephalopathy (CTE) is a progressive neurodegenerative syndrome that can affect athletes. It is thought to result from concussion and brain injury following repeated blows to the head.

But the topic of brain damage in football is controversial. The National Football League, for example, does not acknowledge any association between football and brain injury.

CTE symptoms include memory problems, depression, poor impulse and motor control, anger and apathy. But diagnosis can be confirmed only with an autopsy.

Over the course of the last 60 years, just 63 cases of CTE have been identified. When compared to the millions of football players, this number is very low, explain the authors, and this makes research "challenging" as definitive conclusions are difficult to make based on small samples.

Consequently, it will take time and further research to make American football safer, but it must remain a top priority, they argue.

All cases of confirmed CTE following autopsy suggest that the condition is linked to repetitive blows to the head.

But not all of these persons had a history of concussion and this suggests that undiagnosed subconcussive blows may also contribute to CTE, they explain, and call for more research into how the condition develops and to determine other risk factors.

Previous research has shown that retired NFL players demonstrated more cognitive impairment if they had started playing football at a younger age, and this suggests the role of long term injuries to the head.

The development of new technologies that can measure subconcussive blows would benefit research, add the authors. For example, helmet mounted accelerometers can measure these blows and has shown that high school players can sustain over 1,000 head impacts per season. But the NFL recently stopped its use because of difficulties and questions over the reliability of such data.

Risk reduction of head injuries has included legislation requiring injured athletes to be medically assessed before returning to play and changing rules to avoid or reduce head trauma. But long term studies still need to assess whether these strategies are effective, they add.

Protective equipment, such as helmets, have been implemented, but have mixed results and more mechanisms to reduce trauma and to treat injuries should be developed and evaluated, they argue.

"We are still lacking a clear clinical picture because there have been no long term prospective studies of the disease spectrum from diagnosis to death," write the authors. "It is unclear whether any treatment could slow progression of the disease if it was recognised early."

http://www.sciencedaily.com/releases/2015/03/150324210049.htm