Chronic traumatic encephalopathy (CTE) has increasingly concerned everyone, from scientists and physicians to sports fans and parents of young athletes. The progressive and fatal brain disease, which is associated with repeated TBIs, or traumatic brain injuries, has even led some professional high-contact sports leagues– such as the NFL– to alter their game rules.
But, for years, researchers studying CTE thought that the primary factor was repeated blows to the head– regardless of whether those hits resulted in concussions. Scientists believed that people who more frequently experienced head hits were more likely to develop cognitive and neurological issues later in life.
Well, new research conducted in collaboration between researchers from Boston University, Harvard Medical School, and Mass General Brigham has suggested otherwise.
The study used brains donated to Boston University’s UNITE Brain Bank and discovered that the “cumulative force” of thousands of blows to the head was the most distinct indicator of what could result in a person suffering from brain disease later on in life– not the volume of concussions experienced.
This research, published in Nature Communications, represents the largest study effort to date and set out to examine the root causes of CTE, which has been linked to everything from impulsive behavior and memory loss to depression.
The team used data collected from 34 past studies that tracked hits to the head measured by sensors located inside players’ football helmets. Then, in the new study, the scientists could actually see how the brains of 631 former football players were impacted.
The most severe forms of CTE were present in football players who had experienced the greatest cumulative force in terms of blows to the head. In other words, players who were hit often and hard, usually holding field positions of wide receiver, running back, or defensive back.
Right now, CTE can only be definitively diagnosed postmortem. Jesse Mez, a senior author of the study, detailed how this research allowed the team to uncover a better predictor of CTE development later in life.
“Previously, we have shown that there is a dose-response relationship between years of football play and risk for CTE. Our new study extends this finding by projecting football helmet sensor data obtained from living players onto our brain donors based on their duration, level, and position of play,” Mez began.