Researchers have found elevated amounts of abnormal tau protein in brain regions affected by chronic traumatic encephalopathy (CTE) in a small group of living former National Football League (NFL) players with cognitive, mood, and behavior symptoms, they report.
An experimental positron emission tomography (PET) scan was used in the study, published recently in the New England Journal of Medicine.
The researchers also found the more years of tackle football played (across all levels of play), the higher the tau protein levels detected by the PET scan. However, there was no relationship between the tau PET levels and cognitive test performance or severity of mood and behavior symptoms, a media release from Boston University School of Medicine explains.
“The results of this study provide initial support for the flortaucipir PET scan to detect abnormal tau from CTE during life. However, we’re not there yet,” corresponding author Robert Stern, PhD, professor of neurology, neurosurgery and anatomy and neurobiology at Boston University School of Medicine (BUSM) cautions.
“These results do not mean that we can now diagnose CTE during life or that this experimental test is ready for use in the clinic.”
The study was conducted in Boston and Arizona by a multidisciplinary group of researchers from BUSM, Banner Alzheimer’s Institute, Mayo Clinic Arizona, Brigham and Women’s Hospital and Avid Radiopharmaceuticals. Experimental flortaucipir PET scans were used to assess tau deposition and FDA-approved florbetapir PET scans were used to assess amyloid plaque deposition in the brains of 26 living former NFL players with cognitive, mood, and behavior symptoms (ages 40-69) and a control group of 31 same-age men without symptoms or history of traumatic brain injury.
Results showed that the tau PET levels were significantly higher in the former NFL group than in the controls, and the tau was seen in the areas of the brain which have been shown to be affected in post-mortem cases of neuropathologically diagnosed CTE.
Interestingly, the former player and control groups did not differ in their amyloid PET measurements. Indeed, only one former player had amyloid PET measurements comparable to those seen in Alzheimer’s disease, the release continues.
“Our findings suggest that mild cognitive, emotional, and behavioral symptoms observed in athletes with a history of repetitive impacts are not attributable to AD, and they provide a foundation for additional research studies to advance the scientific understanding, diagnosis, treatment, and prevention of CTE in living persons,” states co-author, Eric Reiman, MD, executive director of Banner Alzheimer’s Institute in Phoenix.
“More research is needed to draw firm conclusions, and contact sports athletes, their families, and other stakeholders are waiting.
With support from National Institutes of Health, the authors are working with additional researchers to conduct a longitudinal study called the DIAGNOSE CTE Research Project in former NFL players, former college football players, and persons without a history of contact sports play to help address these and other important questions. Initial results of that study are expected in early 2020, the release concludes.
[Source(s): Boston University School of Medicine, Science Daily]