Citation

Kawata K, Rubin LH, Takahagi M, Lee J, Sim T, Szwanki V, Bellamy A, Tierney R, Langford D. J. Neurotrauma 2017; 34(14): 2254-2260.

Affiliation

Temple University School of Medicine, Neuroscience , 3500 N. Broad St , Philadelphia, Pennsylvania, United States , 19140 ; tdl@temple.edu.

Copyright

(Copyright © 2017, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2016.4786

PMID

28181857

Abstract

The current study investigates whether repetitive subconcussive impacts cause changes in plasma S100β levels, and further to test the associations between S100β changes and frequency/magnitude of impacts sustained. This prospective study of 22 Division-I collegiate American football players included baseline and pre-season practices [1 helmet-only and 4 full-gear]. Blood samples were obtained and assessed for S100β levels at baseline and pre-post practices; symptom scores were assessed at each time point. An accelerometer-embedded mouthguard was employed to measure number of impacts (hits), peak linear acceleration (PLA), and peak rotational acceleration (PRA). Because we observed a distinct gap in impact exposure (hits, PLA, PRA), players were clustered into lower (n=7) or higher (n=15) impact groups based on the sum of impact kinematics from all 5 practices. S100β levels significantly changed across study duration. While S100β levels remained stable from baseline to all pre-practice values, statistically significant acute increases in S100β levels were observed in all post-practice measures compared to the respective pre-practice values (range: 133-246% in the overall sample). Greater numbers of hits, sum of PLA, and PRA were significantly associated with greater acute increases in S100β levels. There were significant differences in head impact kinematics between lower and higher impact groups [hits, 6 vs. 43 (Mlower-Mhigher=35, p<0.001); PLA, 99.4 vs. 1,148.5g (Mlower-Mhigher=1049.1, p<0.001); PRA, 7,589 vs. 68,259rad/s2 (Mlower-Mhigher=60,670, p<0.001)]. Players in the higher impact group showed consistently greater increases in plasma S100β levels, but not symptom scores, at each post-practice than the lower impact group. Collectively, these data suggest that while players continued to play without noticeable change in symptom, a brain-enriched serological factor suggests an acute burden from head impacts. Assessing the effects of repetitive subconcussive head impacts on acute changes in S100β levels may be a clinically useful blood biomarker in tracking real-time acute brain damage in collegiate football players.

Language: en

Keywords

ADULT BRAIN INJURY; BIOMARKERS; GLIA CELL RESPONSE TO INJURY; HEAD TRAUMA; HUMAN STUDIES