Cortical thinning in former professional soccer players

Abstract

Soccer is the most popular sport in the world. Soccer players are at high risk for repetitive subconcussive head impact when heading the ball. Whether this leads to long-term alterations of the brain's structure associated with cognitive decline remains unknown. The aim of this study was to evaluate cortical thickness in former professional soccer players using high-resolution structural MR imaging. Fifteen former male professional soccer players (mean age 49.3 [SD 5.1] years) underwent high-resolution structural 3 T MR imaging, as well as cognitive testing. Fifteen male, age-matched former professional non-contact sport athletes (mean age 49.6 [SD 6.4] years) served as controls. Group analyses of cortical thickness were performed using voxel-based statistics. Soccer players demonstrated greater cortical thinning with increasing age compared to controls in the right inferolateral-parietal, temporal, and occipital cortex. Cortical thinning was associated with lower cognitive performance as well as with estimated exposure to repetitive subconcussive head impact. Neurocognitive evaluation revealed decreased memory performance in the soccer players compared to controls. The association of cortical thinning and decreased cognitive performance, as well as exposure to repetitive subconcussive head impact, further supports the hypothesis that repetitive subconcussive head impact may play a role in early cognitive decline in soccer players. Future studies are needed to elucidate the time course of changes in cortical thickness as well as their association with impaired cognitive function and possible underlying neurodegenerative process.

Persistent effects of playing football and associated (subconcussive) head trauma on brain structure and function: a systematic review of the literature

“…Prospectively observing female high-school players over one season using fMRI, significant reductions in frontotemporal cerebrovascular reactivity persisting up to 4–5 months after the season had ended were reported,54 resembling the pattern described in mTBI 60 61. Retrospectively, in former professionals, VBM demonstrated cortical thinning in the right inferolateral parietal, temporal and occipital cortex37 and MRS showed higher choline and myo-inositol levels in the posterior cingulate gyrus 51. In professional players, DTI indicated widespread white matter abnormalities (albeit no changes in fractional anisotropy),50 but conventional MRI did not demonstrate changes related to the years of football participation 44.…”

“…Four studies linked neuroimaging with neurocognitive data 17 37 38 51. Cortical thinning was associated with worse performance on 1 of 6 tests (Rey-Osterrieth complex-figure long-delay recall),37 Glutathion levels were linked to inferior results in 1 of 4 tests (trail making test B)51 and lower levels of fractional anisotropy in parieto-occipital areas were associated with 1 of 6 tests (poorer memory) 17.…”

“…In two small case–control studies, memory impairment was linked to cortical thinning in former professionals37 and to diffuse white matter abnormalities in amateur players,17 while recently in a prospective case–control study over 5 years in professional players, no such link could be drawn 38…”

Impaired Cognitive Performance in Youth Athletes Exposed to Repetitive Head Impacts

“…However, recent evidence suggests that RHI, especially if they occur in close proximity in time, may lead to structural and functional brain alterations and clinical impairment even if there are no acute symptoms [2][3][4][5] (for review see Koerte et al 6 ). More severe effects are expected when a child with insufficient neck strength attempts to head a ball 7 .…”

184 Interrelationships Among Neuroimaging Biomarkers, Neuropsychological Test Data, and Symptom Reporting in a Cohort of Retired National Football League Players

“…Routine magnetic resonance imaging (MRI) can assess various anatomical parameters, including cortical thinning 34 and cavum septum pellucidum. 20,44 Diffusion tensor imaging (DTI) is a noninvasive MRI method that uses the diffusion properties of water to generate measures of white matter structural integrity within the brain.…”