Imaging Brain Injury in Former National Football League Players

Area of Science:

• Neuroscience
• Radiology
• Sports Medicine

Background:

• Pilot studies indicated elevated 18 kDa translocator protein (TSPO) in the brains of National Football League (NFL) players.
• TSPO is a marker of neuroinflammation and glial activation, relevant to brain injury and repair.
• Collision sports carry a risk of repetitive head trauma, potentially leading to chronic neuroinflammation.

Purpose of the Study:

• To investigate higher TSPO levels in former NFL players compared to elite athletes from non-collision sports.
• To assess the relationship between TSPO levels and cognitive function in former NFL players.

Main Methods:

• Cross-sectional study utilizing carbon 11-labeled N,N-diethyl-2-(4-methoxyphenyl)-5,7-dimethylpyrazolo[1,5-a]pyrimidine-3-acetamide positron emission tomography ([11C]DPA-713 PET) imaging.
• Compared 27 former NFL players with 27 former elite non-collision sport athletes.
• Assessed regional TSPO distribution volume, brain volumes via MRI, and neuropsychological performance (attention, executive function, memory).

Main Results:

• Former NFL players exhibited significantly higher regional TSPO levels than non-collision athletes (P < .001).
• The greatest TSPO differences were observed in the cingulate cortex, frontal cortex, and hippocampus.
• Former NFL players showed poorer performance in learning and memory domains compared to controls (P < .003).

Conclusions:

• Elevated brain TSPO in former NFL players suggests ongoing neuroinflammation, even years after retiring from play.
• Findings support the link between participation in collision sports and sustained neuroimmune activation.
• Longitudinal studies with [11C]DPA-713 PET and neuropsychological testing are warranted to explore therapeutic interventions.