|Abstract:||A concussion is a type of mild traumatic brain injury (mTBI) resulting from a bump, blow, or jolt to the head or body that causes rapid movement of the head and brain. A neurometabolic crisis results, causing an ionic flux and the release of glutamate to resolve the injured brain’s energy demands. In the majority of cases, individuals make a full recovery as the byproduct of cognitive and physical rest. When individuals do not return to normal levels of functioning, chronic cell death, neuronal dysfunction, and neurodegeneration may underlie long-term impairment (>1 month). Postconcussion syndrome (PCS) refers to the collection of lingering symptoms that follows concussion. PCS has become a major public health concern due to its increasing prevalence and lack of consensus regarding a scientifically valid treatment protocol. Symptoms such as headache, difficulty concentrating, and depressed mood may continue for weeks, months, and even years after the injury. Despite evidence of cognitive and affective benefits of physical activity, individuals with lingering symptoms are often reluctant to engage in exercise for fear of symptom exacerbation. However, recent scientific evidence has supported engagement in aerobic exercise to reduce symptom severity. In addition to aerobic exercise, cognitive training is a tool often used to improve cognitive deficits. Relying on brain plasticity-based learning, cognitive training targets specific cognitive abilities such as attentional control that may translate into a reduction of PCS symptoms. To date, no studies have tested the combined effects of aerobic exercise and cognitive training on refractory postconcussion symptom reduction.
The purpose of this study was to examine the efficacy of a multimodal, center and home-based training program involving aerobic exercise and cognitive training on symptom reduction among individuals with refractory symptoms of concussion, mTBI, or other head injury. Participants were randomized to one of three conditions: (1) an aerobic exercise and cognitive training group, (2) an aerobic exercise and video watching group, or (3) a control group. Results of a repeated measures analysis of covariance indicated statistically significant within-group effects [F(2,26) = 6.54, p < .05, d = .72] and between-group effects [F(2,26) = 4.90, p < .05, d = .56] on RPQ-3 ratings as well as within- [F(2,26) = 10.36, p < .05, d = .90] and between-group effects [F(2,26) = 5.51, p < .05, d = .88] on RPQ-13 ratings. Cognition was assessed using assessments from the NIH Toolbox Cognitive Battery. Significant differences on measures of inhibitory control and attention, working memory, processing speed, and executive switching are discussed. Results should be interpreted with caution due to the preliminary nature of the study. Findings can be used to guide future research design and intervention that incorporate multiple approaches for the treatment of PCS.