Repetitive Concussions in Adolescent Athletes – Translating Clinical and Experimental Research into Perspectives on Rehabilitation Strategies

Abstract

Sports-related concussions are particularly common during adolescence, a time when even mild brain injuries may disrupt ongoing brain maturation and result in long-term complications. A recent focus on the consequences of repetitive concussions among professional athletes has prompted the development of several new experimental models in rodents, as well as the revision of guidelines for best management of sports concussions. Here, we consider the utility of rodent models to understand the functional consequences and pathobiology of concussions in the developing brain, identifying the unique behavioral and pathological signatures of concussive brain injuries. The impact of repetitive concussions on behavioral consequences and injury progression is also addressed. In particular, we focus on the epidemiological, clinical, and experimental evidence underlying current recommendations for physical and cognitive rest after concussion, and highlight key areas in which further research is needed. Lastly, we consider how best to promote recovery after injury, recognizing that optimally timed, activity-based rehabilitative strategies may hold promise for the adolescent athlete who has sustained single or repetitive concussions. The purpose of this review is to inform the clinical research community as it strives to develop and optimize evidence-based guidelines for the concussed adolescent, in terms of both acute and long-term management.

Sex matters: repetitive mild traumatic brain injury in adolescent rats

“…Furthermore, although the design of this study limits the interpretation of the differences between the single and RmTBI groups (i.e., different recovery times before the onset of behavioral testing – discussed further below), there was a trend in the beam testing data indicating that the RmTBI rats had more slips and falls 24 h after the third mTBI compared to 24 h after the first mTBI, suggesting a cumulative effect with the repeated injuries. Although there is some preliminary human evidence that adolescents may experience worse mTBI outcomes than young adults (see Semple et al, 2015),44 many of the changes in the current study are similar to those observed in adult rats given repeated mTBI. For example, adult male rats administered repeated mild fluid percussion injuries had cumulative and persisting cognitive deficits, motor abnormalities, anxiety‐like behavior, and depression 45, 46.…”

Patterns of referral in high school concussion management programs: A pilot study of consultants from different disciplines

“…Specifically, more information regarding reasons for lengthier recovery times with non-NP consults would be beneficial. The number of prolonged concussions (those that take longer than 2 weeks to recover) represents a small percentage of total concussions, but is an important subset of cases due to implications for serious injury and prolonged recovery times (Semple et al, 2015). The median time to the last CNT was longer in this cohort than that reported in the literature, as was the number of cases taking longer than 2 weeks.…”

From blast to bench: A translational mini‐review of posttraumatic headache

“…In addition, in vitro models reflecting brain cell–specific changes that occur following trauma could be a promising strategy for high‐throughput screening of emerging therapies. Furthermore, repetitive TBI has recently received a lot of attention in sports and the military, and animal models have been developed to study this type of injury (Kane et al, ; Semple et al, ; McAteer et al, ; Ojo et al, ; Winston et al, ). Future preclinical studies focused on the effect of repetitive TBI on PTH‐associated symptoms would provide much needed insight on how the brain's pain‐processing regions adapt to repeated injury.…”