TY - JOUR T1 - Analysis of head impact exposure and brain microstructure response in a season-long application of a jugular vein compression collar: a prospective, neuroimaging investigation in American football JF - British Journal of Sports Medicine JO - Br J Sports Med SP - 1276 LP - 1285 DO - 10.1136/bjsports-2016-096134 VL - 50 IS - 20 AU - Gregory D Myer AU - Weihong Yuan AU - Kim D Barber Foss AU - Staci Thomas AU - David Smith AU - James Leach AU - Adam W Kiefer AU - Chris Dicesare AU - Janet Adams AU - Paul J Gubanich AU - Katie Kitchen AU - Daniel K Schneider AU - Daniel Braswell AU - Darcy Krueger AU - Mekibib Altaye Y1 - 2016/10/01 UR - http://bjsm.bmj.com/content/50/20/1276.abstract N2 - Background Historical approaches to protect the brain from outside the skull (eg, helmets and mouthpieces) have been ineffective in reducing internal injury to the brain that arises from energy absorption during sports-related collisions. We aimed to evaluate the effects of a neck collar, which applies gentle bilateral jugular vein compression, resulting in cerebral venous engorgement to reduce head impact energy absorption during collision. Specifically, we investigated the effect of collar wearing during head impact exposure on brain microstructure integrity following a competitive high school American football season.Methods A prospective longitudinal controlled trial was employed to evaluate the effects of collar wearing (n=32) relative to controls (CTRL; n=30) during one competitive football season (age: 17.04±0.67 years). Impact exposure was collected using helmet sensors and white matter (WM) integrity was quantified based on diffusion tensor imaging (DTI) serving as the primary outcome.Results With similar overall g-forces and total head impact exposure experienced in the two study groups during the season (p>0.05), significant preseason to postseason changes in mean diffusivity, axial diffusivity and radial diffusivity in the WM integrity were noted in the CTRL group (corrected p<0.05) but not in the collar group (p>0.05). The CTRL group demonstrated significantly larger preseason to postseason DTI change in multiple WM regions compared with the collar group (corrected p<0.05).Discussion Reduced WM diffusivity alteration was noted in participants wearing a neck collar after a season of competitive football. Collar wearing may have provided a protective effect against brain microstructural changes after repetitive head impacts.Trial registration number NCT02696200. ER -