New University at Buffalo research is adding important information to the body of knowledge about the cognitive and behavioral status of a group of retired professional athletes who spent their careers in contact sports.

The study findings, from UB's Healthy Aging Mind Project, were published online before print in the Journal of Head Trauma Rehabilitation. The study assessed 21 professional athletes retired from the National Football League and the National Hockey League on neuropsychological measures associated with mild cognitive impairment and executive function.

The comprehensive, case-control study is believed to be the first age-matched athlete comparison designed to identify in retired living athletes cognitive symptoms or imaging findings that would indicate the presence of early onset dementia.

Most athletes with CTE damage do experience early onset dementia, although there is also some evidence that it may be possible to have CTE damage without clinical symptoms. The condition can only be diagnosed for certain after death.

'How prevalent is the problem?'

The UB study was begun, in part, to address some limitations of previous studies on athletes and CTE. In pathological studies done at Boston University, CTE has been found in the brains of nearly all professional football and hockey players, many of whom had clearly exhibited dementia, and whose brains were donated for study by their families.

The assumption has been that CTE is a result of repetitive concussions and/or non-concussive hits sustained while playing sports. It has also been seen in the brains of much younger individuals. Investigators on these postmortem studies have cited selection bias and the lack of a control group, that is, donated brains from people who didn't play contact sports, as important limitations.

Assessing cognitive function

The case-control study provides the first age-matched athlete comparison designed to identify in retired living athletes cognitive symptoms or imaging findings that would indicate early onset dementia.

The researchers did find evidence of mild cognitive impairment (MCI) in more of the retired athletes than the controls, but said the rate was as expected for the age, education level and body mass index of the athletes, all factors that can raise the risk of MCI; it also was not statistically significant.

Advanced brain imaging detected no microscopic or macroscopic brain tissue injury differences in retired athletes versus the controls. The non-contact sport athletes were found to have a higher rate of microbleeds in the brain but these results only approached statistical significance

Recruiting athletes

The UB researchers found that the athletes had valuable insights on how to frame the research. They also discovered that many athletes were interested in the research, exhibiting concerns that they, themselves, might be showing early signs of dementia.

The study groups underwent comprehensive neuropsychological testing designed to identify MCI, considered an early sign of dementia. They filled out questionnaires about executive function and personality and underwent advanced brain imaging through magnetic resonance imaging (MRI).

A key goal was to try to determine if symptoms signaling CTE, specifically, early-onset dementia, could be seen in retired professional athletes and how they compared with athletes who didn't play a contact sport. The researchers also wanted to assist former players and their families in addressing changes they were experiencing as a result of aging.

Significant physical toll

"We did find the former athletes to be quite physically affected," Leddy said. "Some of them have had knees or hips replaced, many are in chronic pain, they have arthritis and some are not just overweight but obese." Sleep apnea also was reported by a number of the athletes.