title: Perfusion Neuroimaging Abnormalities Alone Distinguish National Football League Players from a Healthy Population.
abstract: National Football League (NFL) players are exposed to multiple head collisions during their careers. Increasing awareness of the adverse long-term effects of repetitive head trauma has raised substantial concern among players, medical professionals, and the general public.
  
  
  
  To determine whether low perfusion in specific brain regions on neuroimaging can accurately separate professional football players from healthy controls.
  
  
  
  A cohort of retired and current NFL players (n = 161) were recruited in a longitudinal study starting in 2009 with ongoing interval follow up. A healthy control group (n = 124) was separately recruited for comparison. Assessments included medical examinations, neuropsychological tests, and perfusion neuroimaging with single photon emission computed tomography (SPECT). Perfusion estimates of each scan were quantified using a standard atlas. We hypothesized that hypoperfusion particularly in the orbital frontal, anterior cingulate, anterior temporal, hippocampal, amygdala, insular, caudate, superior/mid occipital, and cerebellar sub-regions alone would reliably separate controls from NFL players. Cerebral perfusion differences were calculated using a one-way ANOVA and diagnostic separation was determined with discriminant and automatic linear regression predictive models.
  
  
  
  NFL players showed lower cerebral perfusion on average (p < 0.01) in 36 brain regions. The discriminant analysis subsequently distinguished NFL players from controls with 90% sensitivity, 86% specificity, and 94% accuracy (95% CI 95-99). Automatic linear modeling achieved similar results. Inclusion of age and clinical co-morbidities did not improve diagnostic classification.
  
  
  
  Specific brain regions commonly damaged in traumatic brain injury show abnormally low perfusion on SPECT in professional NFL players. These same regions alone can distinguish this group from healthy subjects with high diagnostic accuracy. This study carries implications for the neurological safety of NFL players.
authors.affiliation: Amen Clinics, Inc., Costa Mesa, CA, USA.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Amen
authors.affiliation: Amen Clinics, Inc., Costa Mesa, CA, USA.
authors.forename: Kristen
authors.initials: K
authors.lastname: Willeumier
authors.affiliation: Department of Pathology, University of California, Davis, CA, USA.
authors.forename: Bennet
authors.initials: B
authors.lastname: Omalu
authors.affiliation: Myrna Brind Center of Integrative Medicine, Thomas Jefferson University, Philadelphia, PA, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Newberg
authors.affiliation: Department of Computer Science, University of Southern California, Los Angeles, CA, USA.
authors.forename: Cauligi
authors.initials: C
authors.lastname: Raghavendra
authors.affiliation: Department of Radiology, University of California Los Angeles Medical Center, Los Angeles, CA, USA.
authors.forename: Cyrus A
authors.initials: CA
authors.lastname: Raji
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology; D000070642:Brain Injuries, Traumatic / Q000000981:diagnostic imaging* / Q000209:etiology; D015331:Cohort Studies; D005260:Female; D005538:Football / Q000293:injuries*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D012179:Retirement; D015899:Tomography, Emission-Computed, Single-Photon
keywords: Brain imaging; NFL; SPECT; cognition; concussion; football; traumatic brain injury