title: Age of first exposure to football and later-life cognitive impairment in former NFL players.
abstract: OBJECTIVE
  To determine the relationship between exposure to repeated head impacts through tackle football prior to age 12, during a key period of brain development, and later-life executive function, memory, and estimated verbal IQ.
  
  
  METHODS
  Forty-two former National Football League (NFL) players ages 40-69 from the Diagnosing and Evaluating Traumatic Encephalopathy using Clinical Tests (DETECT) study were matched by age and divided into 2 groups based on their age of first exposure (AFE) to tackle football: AFE <12 and AFE ≥12. Participants completed the Wisconsin Card Sort Test (WCST), Neuropsychological Assessment Battery List Learning test (NAB-LL), and Wide Range Achievement Test, 4th edition (WRAT-4) Reading subtest as part of a larger neuropsychological testing battery.
  
  
  RESULTS
  Former NFL players in the AFE <12 group performed significantly worse than the AFE ≥12 group on all measures of the WCST, NAB-LL, and WRAT-4 Reading tests after controlling for total number of years of football played and age at the time of evaluation, indicating executive dysfunction, memory impairment, and lower estimated verbal IQ.
  
  
  CONCLUSIONS
  There is an association between participation in tackle football prior to age 12 and greater later-life cognitive impairment measured using objective neuropsychological tests. These findings suggest that incurring repeated head impacts during a critical neurodevelopmental period may increase the risk of later-life cognitive impairment. If replicated with larger samples and longitudinal designs, these findings may have implications for safety recommendations for youth sports.
authors: From the CTE Center (J.M.S., A.P.B., C.M.B., N.G.F., D.H.D., Y.T., R.A.S.), Department of Anatomy and Neurobiology (J.M.S., R.A.S.), BU Alzheimer's Disease Center (A.P.B., Y.T., R.A.S.), Department of Neurology (C.M.B., R.A.S.), and Department of Neurosurgery (R.A.S.), Boston University School of Medicine; and Data Coordinating Center (B.M.M.), Department of Environmental Health (M.D.M.), and Department of Biostatistics (Y.T.), Boston University School of Public Health, Boston, MA.
authors: Julie M
authors: JM
authors: Stamm
authors: From the CTE Center (J.M.S., A.P.B., C.M.B., N.G.F., D.H.D., Y.T., R.A.S.), Department of Anatomy and Neurobiology (J.M.S., R.A.S.), BU Alzheimer's Disease Center (A.P.B., Y.T., R.A.S.), Department of Neurology (C.M.B., R.A.S.), and Department of Neurosurgery (R.A.S.), Boston University School of Medicine; and Data Coordinating Center (B.M.M.), Department of Environmental Health (M.D.M.), and Department of Biostatistics (Y.T.), Boston University School of Public Health, Boston, MA.
authors: Alexandra P
authors: AP
authors: Bourlas
authors: From the CTE Center (J.M.S., A.P.B., C.M.B., N.G.F., D.H.D., Y.T., R.A.S.), Department of Anatomy and Neurobiology (J.M.S., R.A.S.), BU Alzheimer's Disease Center (A.P.B., Y.T., R.A.S.), Department of Neurology (C.M.B., R.A.S.), and Department of Neurosurgery (R.A.S.), Boston University School of Medicine; and Data Coordinating Center (B.M.M.), Department of Environmental Health (M.D.M.), and Department of Biostatistics (Y.T.), Boston University School of Public Health, Boston, MA.
authors: Christine M
authors: CM
authors: Baugh
authors: From the CTE Center (J.M.S., A.P.B., C.M.B., N.G.F., D.H.D., Y.T., R.A.S.), Department of Anatomy and Neurobiology (J.M.S., R.A.S.), BU Alzheimer's Disease Center (A.P.B., Y.T., R.A.S.), Department of Neurology (C.M.B., R.A.S.), and Department of Neurosurgery (R.A.S.), Boston University School of Medicine; and Data Coordinating Center (B.M.M.), Department of Environmental Health (M.D.M.), and Department of Biostatistics (Y.T.), Boston University School of Public Health, Boston, MA.
authors: Nathan G
authors: NG
authors: Fritts
authors: From the CTE Center (J.M.S., A.P.B., C.M.B., N.G.F., D.H.D., Y.T., R.A.S.), Department of Anatomy and Neurobiology (J.M.S., R.A.S.), BU Alzheimer's Disease Center (A.P.B., Y.T., R.A.S.), Department of Neurology (C.M.B., R.A.S.), and Department of Neurosurgery (R.A.S.), Boston University School of Medicine; and Data Coordinating Center (B.M.M.), Department of Environmental Health (M.D.M.), and Department of Biostatistics (Y.T.), Boston University School of Public Health, Boston, MA.
authors: Daniel H
authors: DH
authors: Daneshvar
authors: From the CTE Center (J.M.S., A.P.B., C.M.B., N.G.F., D.H.D., Y.T., R.A.S.), Department of Anatomy and Neurobiology (J.M.S., R.A.S.), BU Alzheimer's Disease Center (A.P.B., Y.T., R.A.S.), Department of Neurology (C.M.B., R.A.S.), and Department of Neurosurgery (R.A.S.), Boston University School of Medicine; and Data Coordinating Center (B.M.M.), Department of Environmental Health (M.D.M.), and Department of Biostatistics (Y.T.), Boston University School of Public Health, Boston, MA.
authors: Brett M
authors: BM
authors: Martin
authors: From the CTE Center (J.M.S., A.P.B., C.M.B., N.G.F., D.H.D., Y.T., R.A.S.), Department of Anatomy and Neurobiology (J.M.S., R.A.S.), BU Alzheimer's Disease Center (A.P.B., Y.T., R.A.S.), Department of Neurology (C.M.B., R.A.S.), and Department of Neurosurgery (R.A.S.), Boston University School of Medicine; and Data Coordinating Center (B.M.M.), Department of Environmental Health (M.D.M.), and Department of Biostatistics (Y.T.), Boston University School of Public Health, Boston, MA.
authors: Michael D
authors: MD
authors: McClean
authors: From the CTE Center (J.M.S., A.P.B., C.M.B., N.G.F., D.H.D., Y.T., R.A.S.), Department of Anatomy and Neurobiology (J.M.S., R.A.S.), BU Alzheimer's Disease Center (A.P.B., Y.T., R.A.S.), Department of Neurology (C.M.B., R.A.S.), and Department of Neurosurgery (R.A.S.), Boston University School of Medicine; and Data Coordinating Center (B.M.M.), Department of Environmental Health (M.D.M.), and Department of Biostatistics (Y.T.), Boston University School of Public Health, Boston, MA.
authors: Yorghos
authors: Y
authors: Tripodis
authors: From the CTE Center (J.M.S., A.P.B., C.M.B., N.G.F., D.H.D., Y.T., R.A.S.), Department of Anatomy and Neurobiology (J.M.S., R.A.S.), BU Alzheimer's Disease Center (A.P.B., Y.T., R.A.S.), Department of Neurology (C.M.B., R.A.S.), and Department of Neurosurgery (R.A.S.), Boston University School of Medicine; and Data Coordinating Center (B.M.M.), Department of Environmental Health (M.D.M.), and Department of Biostatistics (Y.T.), Boston University School of Public Health, Boston, MA. bobstern@bu.edu.
authors: Robert A
authors: RA
authors: Stern
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001924:Brain Concussion / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D002648:Child; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D015331:Cohort Studies; D005538:Football / Q000293:injuries* / Q000639:trends; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012307:Risk Factors
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