Brain trauma researchers found that 110 of 111 brains donated by NFL players to science have signs of chronic traumatic encephalopathy (CTE), according to a new study published Tuesday in the Journal of the American Medical Association.
Led by Boston University researcher Dr. Ann McKee, researchers from Boston University and the VA Boston Healthcare System study examined the brains of 202 football players who donated their brains to science after their death, including 111 NFL players, according to CNN. The study found CTE in 177 brains examined, including in 99 percent of NFL players, for an overall rate of 87 percent.
Several NFL players confirmed to have CTE were included in the study, including Dave Duerson, Ken Stabler, Kevin Turner, and Bubba Smith, according to CNN.
The study examined athletes who played football in high school, college, or in the NFL. The study found a direct correlation between level of play and frequency of CTE; high school football players were the least likely to develop the disease.
“Obviously, this doesn’t represent the prevalence in the general population, but the fact that we’ve been able to gather this high a number of cases in such a short period of time says that this disease is not uncommon,” said Dr. McKee.
Although the study provides a snapshot of the development of CTE, McKee also points out that the selection of brains included in the study was not random.
Families are significantly more likely to donate an athlete’s brain to science after death if they exhibited any odd neurological, physical, or emotional symptoms during their lifetime, McKee told the Salt Lake Tribune. In addition, accidental deaths or suicides will prompt a family to donate a brain, all factors and symptoms associated with CTE, she said.
McKee said that while the study doesn’t prove football players develop CTE at a particular rate, it does offer definitive “overwhelmingly circumstantial evidence” of a causal link between football and CTE.
However, she said the information gathered would be further examined, including looking at the 177 brains diagnosed with CTE for a genetic link.
“We know that this study doesn’t answer many of the very important questions in CTE, but the resource will help us understand the molecular underpinnings, will help us develop biomarkers and therapies by understanding the pathological features of the disease,” she said.
The NFL announced last year that it would donate $100 million to neurological studies after announcing that it acknowledged a link between football-related head trauma and CTE. However, in previous years the NFL attempted to deny links between head trauma and CTE.
In June 2015, a federal judge ruled against NFL in a class-action lawsuit brought by thousands of former players asserting that playing football for the NFL caused them to sustain serious medical conditions related to chronic head trauma. The judge awarded up to $5 million per player in the lawsuit, according to CNN.
CTE can only be diagnosed in an autopsy, which makes it difficult to identify during one’s lifetime. However, individuals with the disease report a variety of mood- and behavior-related symptoms during their lifetime, such as increased rates of depression and suicide attempts, impulsiveness, feelings of hopelessness, and bouts of violence or violent urges. Individuals also report cognitive problems, memory problems, and difficulty concentrating.
The study included brains from players who were active from the 1950s to present day. Football procedures, intensity, and protective gear have changed significantly over the decades, which means the study is not conclusive, according to Dr. Jeffrey Kutcher, national director of the Sports Neurology Clinic at the Core Institute.
[Featured Image by Bill Chan/AP Images]