title: Age at First Exposure to Football Is Associated with Altered Corpus Callosum White Matter Microstructure in Former Professional Football Players.
abstract: Youth football players may incur hundreds of repetitive head impacts (RHI) in one season. Our recent research suggests that exposure to RHI during a critical neurodevelopmental period prior to age 12 may lead to greater later-life mood, behavioral, and cognitive impairments. Here, we examine the relationship between age of first exposure (AFE) to RHI through tackle football and later-life corpus callosum (CC) microstructure using magnetic resonance diffusion tensor imaging (DTI). Forty retired National Football League (NFL) players, ages 40-65, were matched by age and divided into two groups based on their AFE to tackle football: before age 12 or at age 12 or older. Participants underwent DTI on a 3 Tesla Siemens (TIM-Verio) magnet. The whole CC and five subregions were defined and seeded using deterministic tractography. Dependent measures were fractional anisotropy (FA), trace, axial diffusivity, and radial diffusivity. Results showed that former NFL players in the AFE <12 group had significantly lower FA in anterior three CC regions and higher radial diffusivity in the most anterior CC region than those in the AFE ≥12 group. This is the first study to find a relationship between AFE to RHI and later-life CC microstructure. These results suggest that incurring RHI during critical periods of CC development may disrupt neurodevelopmental processes, including myelination, resulting in altered CC microstructure.
authors.affiliation: 1 CTE Center, Boston University School of Medicine , Boston, Massachusetts.|2 Department of Anatomy and Neurobiology, Boston University School of Medicine , Boston, Massachusetts.|3 Psychiatry Neuroimaging Laboratory, Harvard Medical School , Boston, Massachusetts.
authors.forename: Julie M
authors.initials: JM
authors.lastname: Stamm
authors.affiliation: 3 Psychiatry Neuroimaging Laboratory, Harvard Medical School , Boston, Massachusetts.|4 Department of Child and Adolescent Psychiatry, Psychosomatic, and Psychotherapy, Ludwig-Maximilian-University , Munich, Germany .
authors.forename: Inga K
authors.initials: IK
authors.lastname: Koerte
authors.affiliation: 3 Psychiatry Neuroimaging Laboratory, Harvard Medical School , Boston, Massachusetts.|4 Department of Child and Adolescent Psychiatry, Psychosomatic, and Psychotherapy, Ludwig-Maximilian-University , Munich, Germany .
authors.forename: Marc
authors.initials: M
authors.lastname: Muehlmann
authors.affiliation: 3 Psychiatry Neuroimaging Laboratory, Harvard Medical School , Boston, Massachusetts.|15 Department of Radiology, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts.
authors.forename: Ofer
authors.initials: O
authors.lastname: Pasternak
authors.affiliation: 1 CTE Center, Boston University School of Medicine , Boston, Massachusetts.|5 Alzheimer's Disease Center, Boston University School of Medicine , Boston, Massachusetts.
authors.forename: Alexandra P
authors.initials: AP
authors.lastname: Bourlas
authors.affiliation: 1 CTE Center, Boston University School of Medicine , Boston, Massachusetts.|6 Interfaculty Initiative in Health Policy, Harvard University , Boston, Massachusetts.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Baugh
authors.affiliation: 3 Psychiatry Neuroimaging Laboratory, Harvard Medical School , Boston, Massachusetts.
authors.forename: Michelle Y
authors.initials: MY
authors.lastname: Giwerc
authors.affiliation: 3 Psychiatry Neuroimaging Laboratory, Harvard Medical School , Boston, Massachusetts.
authors.forename: Anni
authors.initials: A
authors.lastname: Zhu
authors.affiliation: 3 Psychiatry Neuroimaging Laboratory, Harvard Medical School , Boston, Massachusetts.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Coleman
authors.affiliation: 3 Psychiatry Neuroimaging Laboratory, Harvard Medical School , Boston, Massachusetts.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Bouix
authors.affiliation: 1 CTE Center, Boston University School of Medicine , Boston, Massachusetts.
authors.forename: Nathan G
authors.initials: NG
authors.lastname: Fritts
authors.affiliation: 7 Data Coordinating Center, Boston University School of Public Health , Boston, Massachusetts.
authors.forename: Brett M
authors.initials: BM
authors.lastname: Martin
authors.affiliation: 1 CTE Center, Boston University School of Medicine , Boston, Massachusetts.|5 Alzheimer's Disease Center, Boston University School of Medicine , Boston, Massachusetts.|7 Data Coordinating Center, Boston University School of Public Health , Boston, Massachusetts.|8 Department of Biostatistics, Boston University School of Public Health , Boston, Massachusetts.
authors.forename: Christine
authors.initials: C
authors.lastname: Chaisson
authors.affiliation: 9 Department of Environmental Health, Boston University School of Public Health , Boston, Massachusetts.
authors.forename: Michael D
authors.initials: MD
authors.lastname: McClean
authors.affiliation: 3 Psychiatry Neuroimaging Laboratory, Harvard Medical School , Boston, Massachusetts.|10 Center for Clinical Spectroscopy, Harvard Medical School , Boston, Massachusetts.
authors.forename: Alexander P
authors.initials: AP
authors.lastname: Lin
authors.affiliation: 1 CTE Center, Boston University School of Medicine , Boston, Massachusetts.|11 Department of Neurosurgery, Boston University School of Medicine , Boston, Massachusetts.|12 Sports Legacy Institute , Waltham, Massachusetts.|13 Department of Neurosurgery, Emerson Hospital , Concord, Massachusetts.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Cantu
authors.affiliation: 1 CTE Center, Boston University School of Medicine , Boston, Massachusetts.|5 Alzheimer's Disease Center, Boston University School of Medicine , Boston, Massachusetts.|8 Department of Biostatistics, Boston University School of Public Health , Boston, Massachusetts.
authors.forename: Yorghos
authors.initials: Y
authors.lastname: Tripodis
authors.affiliation: 1 CTE Center, Boston University School of Medicine , Boston, Massachusetts.|2 Department of Anatomy and Neurobiology, Boston University School of Medicine , Boston, Massachusetts.|5 Alzheimer's Disease Center, Boston University School of Medicine , Boston, Massachusetts.|11 Department of Neurosurgery, Boston University School of Medicine , Boston, Massachusetts.|14 Department of Neurology, Boston University School of Medicine , Boston, Massachusetts.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Stern
authors.affiliation: 3 Psychiatry Neuroimaging Laboratory, Harvard Medical School , Boston, Massachusetts.|15 Department of Radiology, Brigham and Women's Hospital, Harvard Medical School , Boston, Massachusetts.|16 VA Boston Healthcare System , Brockton Division, Brockton, Massachusetts.
authors.forename: Martha E
authors.initials: ME
authors.lastname: Shenton
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D016880:Anisotropy; D002648:Child; D002675:Child, Preschool; D003337:Corpus Callosum / Q000293:injuries* / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D005538:Football / Q000293:injuries*; D006801:Humans; D008297:Male; D008875:Middle Aged; D066127:White Matter / Q000293:injuries* / Q000473:pathology*; D055815:Young Adult
keywords: American football; age at first exposure; corpus callosum; diffusion tensor imaging; repetitive head impacts