Perfusion Neuroimaging Abnormalities Alone Distinguish National Football League Players from a Healthy Population.
Level 4 - case-series / case-control
Case-control diagnostic imaging study comparing NFL players to separately recruited healthy controls.
PubMed 27128374 · doi:10.3233/JAD-160207
What was done
Researchers evaluated 161 current and retired National Football League (NFL) players and 124 separately recruited healthy controls. Participants underwent medical evaluations, neuropsychological testing, and single-photon emission computed tomography (SPECT) to quantify regional cerebral perfusion using a standard atlas. Differences in regional perfusion were tested via one-way ANOVA, and predictive classification models (discriminant analysis and automatic linear modeling) were used to test how accurately perfusion patterns alone differentiated players from controls.
What was found
NFL players exhibited significantly lower average cerebral perfusion across 36 brain regions (p < 0.01) compared to healthy controls. Discriminant analysis separated NFL players from controls with 90% sensitivity, 86% specificity, and 94% accuracy (reported 95% CI 95-99). Automatic linear modeling yielded similar performance, and adding age or clinical comorbidities did not improve diagnostic classification.
Why it matters
This study shows that widespread regional cerebral hypoperfusion detected by SPECT correlates with a history of professional football play and repetitive head trauma, providing a potential imaging biomarker profile to distinguish exposed players from healthy non-athletes.
Limits
The use of separately recruited healthy controls rather than non-contact athletic controls risks spectrum bias and confounding from athletic or lifestyle differences. The abstract does not correlate hypoperfusion with cumulative concussion counts, career duration, or specific clinical symptomatology, nor does it establish whether these perfusion abnormalities precede or predict neurodegenerative disease.
Cited by
- supports Dr. Amen scanned and evaluated 300 NFL players in a study starting in 2009 and found high levels of brain damage.