Katie Kitchen

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

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.

White matter alterations over the course of two consecutive high-school football seasons and the effect of a jugular compression collar: A preliminary longitudinal diffusion tensor imaging study

The cumulative effects of repetitive subclinical head impacts during sports may result in chronic white matter (WM) changes and possibly, neurodegenerative sequelae. In this pilot study, we investigated the longitudinal WM changes over the course of two consecutive high‐school football seasons and explored the long‐term effects of a jugular vein compression collar on these WM alterations. Diffusion tensor imaging data were prospectively collected both pre‐ and postseason in the two consecutive seasons. Participants were assigned into either collar or noncollar groups. Tract‐based spatial statistics (TBSS) approach and region of interest‐based approach were used to quantify changes in WM diffusion properties. Despite comparable exposure to repetitive head impacts, significant reductions in mean, axial, and/or radial diffusivity were identified in Season 1 in multiple WM regions in the noncollar group but not in the collar group. After an 8‐ to 9‐month long off‐season, these changes observed in the noncollar group partially and significantly reversed but also remained significantly different from the baseline. In Season 2, trend level WM alterations in the noncollar group were found but located in spatially different regions than Season 1. Last, the WM integrity in the collar group remained unchanged throughout the four time points. In conclusion, we quantitatively assessed the WM structural changes and partial reversal over the course of two consecutive high‐school football seasons. In addition, the mitigated WM alterations in athletes in the collar group might indicate potential effect of the collar in ameliorating the changes against repetitive head impacts. Hum Brain Mapp 39:491–508, 2018.

Pilot Randomized Trial of Integrated Cognitive-Behavioral Therapy and Neuromuscular Training for Juvenile Fibromyalgia: The FIT Teens Program

Cognitive-behavioral therapy (CBT) improves coping and daily functioning in adolescents with juvenile fibromyalgia (JFM), but is less effective in reducing pain. This pilot trial evaluated the efficacy of a novel intervention (Fibromyalgia Integrative Training for Teens; FIT Teens) which integrates CBT with specialized neuromuscular exercise training to enhance the effect of treatment on reducing pain and disability. Forty adolescents with JFM (12-18 years) were randomized to CBT-only or FIT Teens. Treatment was conducted in group-based sessions over 8 weeks with assessments at baseline, post-treatment, and 3-month follow-up (primary end point). Primary outcomes were pain intensity and functional disability. Secondary outcomes were depressive symptoms, fear of movement, and pain catastrophizing. Thirty-six participants (mean age=15.33 years; 90% female) completed the program. Intent to treat analysis was conducted to evaluate differences between the FIT Teens and CBT groups from baseline to 3-month follow-up, controlling for baseline group differences. Participants in the FIT Teens group showed significantly greater decreases in pain than the CBT group. FIT Teens participants also showed significant improvements in disability, but did not differ from CBT-only at the 3-month end point. Results provide preliminary evidence that the FIT Teens intervention provides added benefits beyond CBT in the treatment of JFM, particularly in pain reduction. PERSPECTIVE Results from this pilot randomized controlled trial of a new combined CBT and specialized neuromuscular exercise intervention (FIT Teens), compared with CBT alone suggested that FIT Teens offers stronger treatment benefits than CBT alone at initial treatment follow-up, especially with respect to the outcome of pain reduction.

Brain-Behavior Mechanisms for the Transfer of Neuromuscular Training Adaptions to Simulated Sport: Initial Findings From the Train the Brain Project

CONTEXT A limiting factor for reducing anterior cruciate ligament injury risk is ensuring that the movement adaptions made during the prevention program transfer to sport-specific activity. Virtual reality provides a mechanism to assess transferability, and neuroimaging provides a means to assay the neural processes allowing for such skill transfer. OBJECTIVE To determine the neural mechanisms for injury risk-reducing biomechanics transfer to sport after anterior cruciate ligament injury prevention training. DESIGN Cohort study. SETTING Research laboratory. PARTICIPANTS Four healthy high school soccer athletes. INTERVENTIONS Participants completed augmented neuromuscular training utilizing real-time visual feedback. An unloaded knee extension task and a loaded leg press task were completed with neuroimaging before and after training. A virtual reality soccer-specific landing task was also competed following training to assess transfer of movement mechanics. MAIN OUTCOME MEASURES Landing mechanics during the virtual reality soccer task and blood oxygen level-dependent signal change during neuroimaging. RESULTS Increased motor planning, sensory and visual region activity during unloaded knee extension and decreased motor cortex activity during loaded leg press were highly correlated with improvements in landing mechanics (decreased hip adduction and knee rotation). CONCLUSION Changes in brain activity may underlie adaptation and transfer of injury risk-reducing movement mechanics to sport activity. Clinicians may be able to target these specific brain processes with adjunctive therapy to facilitate intervention improvements transferring to sport.

Sport-specific virtual reality to identify profiles of anterior cruciate ligament injury risk during unanticipated cutting

Female athletes are at an increased risk of anterior cruciate ligament (ACL) injury in competitive sport during running, jumping and cutting tasks. This risk is due to deficits in posterior chain and hip recruitment associated with aberrant frontal knee loads. The identification of these risk factors has led to targeted neuromuscular training (NMT) interventions to enhance hip neuromuscular control during such tasks. Despite the successful modification of ACL injury risk factors following NMT, the transfer of these corrected movement patterns to the sport-specific contexts has not been directly evaluated. Sport-specific virtual reality (VR) may provide the best method to measure training transfer to realistic sport performance, while still allowing appropriate experimental control and high-fidelity performance measurements. The current study examined the effect of a biofeedback-driven augmented NMT (aNMT) on skill transfer of ACL-injury resistant movement patterns during performance of sport-specific VR scenarios. Five trained athletes participated, and their performance on an unanticipated cutting task was assessed in VR prior to and after six weeks of aNMT. A significant 87% reduction in internal hip rotation was observed on the plant leg during the loading phase of cutting (p = .05), along with an observed 116% reduction during the push-off phase (p = .02), from pre- to post-training. A non-significant trend of a 19% reduction in knee abduction was also observed (p = .15). This study is the first that has utilized free ambulatory wireless VR to assess injury risk in athletes during performance of sport-specific tasks. The reduction in internal hip rotation and knee abduction align with previous findings on laboratory based tests. The current results are the first step in the validation of sport-specific VR as a tool for understanding injury risk during simulation of real-world sport performance.