Abstract
Sport concussion (SC) has gained a lot of attention in recent years from scholars, clinicians, athletes, school districts, parents and mainstream media. This increased attention has led to improved recognition of the injury, but there is still understanding to be elucidated regarding the pathophysiology, clinical presentation, and recovery after SC. Patient sex, age, and prior concussion history are all reported to modify recovery trajectories, but the empirical evidence for these claims is mixed. Moreover, there is emerging evidence that physiologic recovery may not align with the typical clinical course of recovery. Most of what is known about pathophysiologic consequences of SC stem from rodent models of experimental brain injuries, and the evidence linking altered physiology to the clinical syndrome that is observed by clinicians and experienced by athletes with SC is sparse.
In the following studies, we examined whole-body metabolism through resting metabolic rate and carbohydrate metabolism, both measures of the physiologic response to SC. Additionally, we estimated physical activity and dietary intake in order to assess energy balance between daily energy consumption and total daily energy expenditure. We examined metrics of clinical recovery in the time to symptom resolution and the time to full return to play. In addition to the physiologic, demographic, and symptom-based measures, we incorporated patient-reported outcomes of sleep disturbance, fatigue, anxiety, perceived resilience and stigma, and appetite. We included high school and collegiate participants diagnosed with SC acutely following their injury and serially assessed these individuals throughout their recovery. Moreover, we matched these participants to non-injured control participants based on age, height, weight, sex and sport in order to provide a meaningful comparator in lieu of a pre-injury baseline assessment.
The results of our studies will direct future research efforts to examine potential new avenues for clinical assessment and intervention after SC. Participants with SC had an energy surplus due to an overconsumption of calories in the initial 10 days following injury. This surplus related to symptom burden and perceived stigma. Males with SC had a lesser magnitude of energy surplus than females, and males who had greater carbohydrate utilization were slower to recover from injury. This suggests that altered fuel utilization and insufficient energy supply may be indicative of more severe injury and may affect recovery. Females with SC in our study recovered faster than their male counterparts. Lastly, sleep disturbance, fatigue, and stigma were all affected by SC acutely and improved throughout recovery. This study corroborates previous research findings in nascent areas of investigation and also reveals new ideas regarding the roles of perceptual, behavioral, and energetic responses to SC.
