Stern RA, et al. - Researchers investigated the feasibility of detecting tau and amyloid deposition in the brains of living people at risk for chronic traumatic encephalopathy (CTE). In all, they found that higher tau levels were evident upon positron-emission tomography (PET) in a group of living former National Football League (NFL) players with cognitive and neuropsychiatric symptoms vs controls in brain regions affected by CTE. Also, they found that these former NFL players did not have elevated amyloid-beta levels.

Methods

• This study included former NFL players with cognitive and neuropsychiatric symptoms, and asymptomatic men with no history of traumatic brain injury.
• Among participants, flortaucipir PET) and florbetapir PET were performed to measure deposition of tau and amyloid-beta, respectively, in their brains.
• Researchers compared the two groups with regard to regional tau standardized uptake value ratio (SUVR; the ratio of radioactivity in a cerebral region to that in the cerebellum as a reference), and determined the associations of SUVR with symptom severity and with years of football play in the former-player group by using automated image-analysis algorithms.

Results

• Overall 26 former players and 31 controls were analyzed.
• Among former players vs controls, higher mean flortaucipir SUVR was detected in three regions of the brain: bilateral superior frontal, bilateral medial temporal, and left parietal.
• In these three regions, the correlation coefficients between the SUVRs and years of play as estimated in exploratory analyses were 0.58, 0.45, and 0.50, respectively.
• Findings revealed no link between tau deposition and scores on cognitive and neuropsychiatric tests.
• Compared with subjects with Alzheimer’s disease, similar levels of amyloid-beta deposition were observed only in one former player.