Perfusion Neuroimaging Abnormalities Alone Distinguish National Football League Players from a Healthy Population

Abstract

Background: 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.Objective: To determine whether low perfusion in specific brain regions on neuroimaging can accurately separate professional football players from healthy controls.Method: 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.Results: 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.Conclusion: 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.

Research Imaging of Brain Structure and Function After Concussion

“…Perfusion imaging with SPECT in a large cohort of 161 active and retired National Football League players showed a 94% accuracy of correctly identifying individual concussed patients from healthy control subjects based on low perfusion rates in 36 frontal, temporal, parietal, and cerebellar brain regions. Areas that most contributed to the predictive accuracy included: anterior superior temporal lobes, Rolandic operculum, insula, superior temporal poles, precuneus, and the cerebellar vermis.…”

“…Studies that have employed machine‐learning algorithms have found encouraging accuracies for: (1) identifying individual patients with recent concussions (<2 months postconcussion) from individual healthy controls; (2) identifying patients with persistent post‐traumatic symptoms (>3 months to 5 years postconcussion) from individual healthy controls; (3) classifying patients with post‐traumatic symptoms (< 5 years postconcussion) and PTSD from individuals with PTSD but without concussion history in the past 5 years; (4) identifying individual concussed patients with recent and remote concussions (months to years postconcussion) from healthy controls; and (5) for separating individual patients with PTSD from patients with TBI …”

A novel repetitive head impact exposure measurement tool differentiates player position in National Football League

“…2) 46,47 . Although these strain magnitudes are considered relatively low, repetitive low magnitude impact frequencies may exhibit structural and/or functional changes that are associated with long-term mental health concerns reported by current and retired football athletes 14,18,[54][55][56][57] . Further, as little as 5-15% strain levels have been associated with functional impairment of signal transmission in vitro [58][59][60][61][62] .…”

“…This has raised awareness of the link between cumulative RHI and the development and/or initiation of neurological disorders, including chronic traumatic open Scientific RepoRtS | (2020) 10:1200 | https://doi.org/10.1038/s41598-019-54874-9www.nature.com/scientificreports www.nature.com/scientificreports/ encephalopathy (CTE). CTE has been associated with exposure to RHI, and often presents with cognitive, motor and psychiatric related deficiencies [17][18][19][20] . The vulnerabilities associated with duration of exposure to RHI are implicated in a number of reports showing higher plasma tau concentrations, increased cognitive impairments and reduced microstructural integrity of the corpus callosum found in retired NFL players compared to their age matched controls 4,16,18,21,22 .Professional ASF is associated with one of the highest rates of documented concussion and the development and pathology of neurological disorder within sport 20,23,24 , and currently accounts for the greatest number of post-mortem diagnosed cases of CTE 25,26 .…”

“…www.nature.com/scientificreports www.nature.com/scientificreports/ encephalopathy (CTE). CTE has been associated with exposure to RHI, and often presents with cognitive, motor and psychiatric related deficiencies [17][18][19][20] . The vulnerabilities associated with duration of exposure to RHI are implicated in a number of reports showing higher plasma tau concentrations, increased cognitive impairments and reduced microstructural integrity of the corpus callosum found in retired NFL players compared to their age matched controls 4,16,18,21,22 .…”