title: Chronic Effects of Boxing: Diffusion Tensor Imaging and Cognitive Findings.
abstract: We used magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) to evaluate the effects of boxing on brain structure and cognition in 10 boxers (8 retired, 2 active; mean age = 45.7 years; standard deviation [SD] = 9.71) and 9 participants (mean age = 43.44; SD = 9.11) in noncombative sports. Evans Index (maximum width of the anterior horns of the lateral ventricles/maximal width of the internal diameter of the skull) was significantly larger in the boxers (F = 4.52; p = 0.050; Cohen's f = 0.531). Word list recall was impaired in the boxers (F(1,14) = 10.70; p = 0.006; f = 0.84), whereas implicit memory measured by faster reaction time (RT) to a repeating sequence of numbers than to a random sequence was preserved (t = 2.52; p < 0.04). Fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) measured by tractography did not significantly differ between groups. However, DTI metrics were significantly correlated with declarative memory (e.g., left ventral striatum ADC with delayed recall, r = -0.74; p = 0.02) and with RT to the repeating number sequence (r = 0.70; p = 0.04) in the boxers. Years of boxing had the most consistent, negative correlations with FA, ranging from -0.65 for the right ventral striatum to -0.92 for the right cerebral peduncle. Years of boxing was negatively related to the number of words consistently recalled over trials (r = -0.74; p = 0.02), delayed recall (r = -0.83; p = 0.003), and serial RT (r = 0.66; p = 0.05). We conclude that microstructural integrity of white matter tracts is related to declarative memory and response speed in boxers and to the extent of boxing exposure. Implications for chronic traumatic encephalopathy are discussed.
authors.affiliation: 1 Rehabilitation Research & Development, Michael E. DeBakey VA Medical Center , Houston, Texas.|2 Baylor College of Medicine , Houston, Texas.
authors.forename: Elisabeth A
authors.initials: EA
authors.lastname: Wilde
authors.affiliation: 2 Baylor College of Medicine , Houston, Texas.
authors.forename: Jill V
authors.initials: JV
authors.lastname: Hunter
authors.affiliation: 2 Baylor College of Medicine , Houston, Texas.
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Li
authors.affiliation: 3 Rice University , Houston, Texas.
authors.forename: Cristian
authors.initials: C
authors.lastname: Amador
authors.affiliation: 2 Baylor College of Medicine , Houston, Texas.
authors.forename: Gerri
authors.initials: G
authors.lastname: Hanten
authors.affiliation: 1 Rehabilitation Research & Development, Michael E. DeBakey VA Medical Center , Houston, Texas.|2 Baylor College of Medicine , Houston, Texas.
authors.forename: Mary R
authors.initials: MR
authors.lastname: Newsome
authors.affiliation: 4 Hauenstein Neurosciences , Mercy Health St. Mary's, Grand Rapids, Michigan.
authors.forename: Trevor C
authors.initials: TC
authors.lastname: Wu
authors.affiliation: 1 Rehabilitation Research & Development, Michael E. DeBakey VA Medical Center , Houston, Texas.|2 Baylor College of Medicine , Houston, Texas.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: McCauley
authors.affiliation: 1 Rehabilitation Research & Development, Michael E. DeBakey VA Medical Center , Houston, Texas.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Vogt
authors.affiliation: 2 Baylor College of Medicine , Houston, Texas.
authors.forename: Zili David
authors.initials: ZD
authors.lastname: Chu
authors.affiliation: 2 Baylor College of Medicine , Houston, Texas.
authors.forename: Brian
authors.initials: B
authors.lastname: Biekman
authors.affiliation: 1 Rehabilitation Research & Development, Michael E. DeBakey VA Medical Center , Houston, Texas.|2 Baylor College of Medicine , Houston, Texas.
authors.forename: Harvey S
authors.initials: HS
authors.lastname: Levin
mesh_terms: D000328:Adult; D001265:Athletic Injuries / Q000150:complications / Q000473:pathology; D001914:Boxing / Q000293:injuries* / Q000523:psychology; D001921:Brain / Q000473:pathology*; D000070627:Chronic Traumatic Encephalopathy / Q000209:etiology* / Q000473:pathology; D056324:Diffusion Tensor Imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory; D008569:Memory Disorders / Q000209:etiology / Q000473:pathology; D008875:Middle Aged; D010865:Pilot Projects; D066127:White Matter / Q000473:pathology*
keywords: boxing; chronic effects; cognition; imaging