title: The effect of repetitive subconcussive collisions on brain integrity in collegiate football players over a single football season: A multi-modal neuroimaging study.
abstract: The cumulative effect of repetitive subconcussive collisions on the structural and functional integrity of the brain remains largely unknown. Athletes in collision sports, like football, experience a large number of impacts across a single season of play. The majority of these impacts, however, are generally overlooked, and their long-term consequences remain poorly understood. This study sought to examine the effects of repetitive collisions across a single competitive season in NCAA Football Bowl Subdivision athletes using advanced neuroimaging approaches. Players were evaluated before and after the season using multiple MRI sequences, including T1-weighted imaging, diffusion tensor imaging (DTI), arterial spin labeling (ASL), resting-state functional MRI (rs-fMRI), and susceptibility weighted imaging (SWI). While no significant differences were found between pre- and post-season for DTI metrics or cortical volumes, seed-based analysis of rs-fMRI revealed significant (p< 0.05) changes in functional connections to right isthmus of the cingulate cortex (ICC), left ICC, and left hippocampus. ASL data revealed significant (p< 0.05) increases in global cerebral blood flow (CBF), with a specific regional increase in right postcentral gyrus. SWI data revealed that 44% of the players exhibited outlier rates (p< 0.05) of regional decreases in SWI signal. Of key interest, athletes in whom changes in rs-fMRI, CBF and SWI were observed were more likely to have experienced high G impacts on a daily basis. These findings are indicative of potential pathophysiological changes in brain integrity arising from only a single season of participation in the NCAA Football Bowl Subdivision, even in the absence of clinical symptoms or a diagnosis of concussion. Whether these changes reflect compensatory adaptation to cumulative head impacts or more lasting alteration of brain integrity remains to be further explored.
authors.affiliation: Concussion Neuroimaging Consortium, Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, United States.
authors.forename: Semyon M
authors.initials: SM
authors.lastname: Slobounov
authors.affiliation: Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, United States.
authors.forename: Alexa
authors.initials: A
authors.lastname: Walter
authors.affiliation: Concussion Neuroimaging Consortium, Department of Psychiatry and Behavioral Sciences, Northwestern University, Evanston, IL 60208, United States.
authors.forename: Hans C
authors.initials: HC
authors.lastname: Breiter
authors.affiliation: Concussion Neuroimaging Consortium, Department of Radiology and Psychology, Michigan State University, East Lansing, MI 48824, United States.
authors.forename: David C
authors.initials: DC
authors.lastname: Zhu
authors.affiliation: Social, Life, and Engineering Sciences Imaging Center, The Pennsylvania State University, University Park, PA 16802, United States.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Bai
authors.affiliation: Athletic Department, The Pennsylvania State University, University Park, PA 16802, United States.
authors.forename: Tim
authors.initials: T
authors.lastname: Bream
authors.affiliation: Athletic Department, The Pennsylvania State University, University Park, PA 16802, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Seidenberg
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, United States.
authors.forename: Xianglun
authors.initials: X
authors.lastname: Mao
authors.affiliation: Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, United States.
authors.forename: Brian
authors.initials: B
authors.lastname: Johnson
authors.affiliation: Concussion Neuroimaging Consortium, School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, United States.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Talavage
mesh_terms: D061725:Accelerometry; D001921:Brain / Q000000981:diagnostic imaging*; D001924:Brain Concussion / Q000000981:diagnostic imaging* / Q000209:etiology*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology; D005538:Football / Q000293:injuries*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009412:Nerve Fibers / Q000473:pathology; D009434:Neural Pathways / Q000000981:diagnostic imaging; D059906:Neuroimaging; D012621:Seasons; D014495:Universities; D055815:Young Adult
keywords: Accelerometers; Football; MRI; Repetitive impacts; Subconcussive