BACKGROUND: Sports-related head trauma has become a major public health concern with significant consequences including persistent post-concussion syndrome (pPCS) and chronic traumatic encephalopathy (CTE). pPCS is a condition where symptoms of single concussion persist years beyond the initial injury. CTE has been characterized as a condition with insidious onset following a latent period after substantial exposure to repetitive head impacts (RHI). Timing of symptom onset usually distinguishes these conditions, however in certain clinical situations a definitive diagnosis is not always clear. For these situations, a measurable distinguishing variable is necessary. LITERATURE REVIEW: Concussions are the most common form of traumatic brain injury (TBI) and are associated with a variety of neurological symptoms that usually resolve within weeks. Post-concussion syndrome (PCS) refers to cases where symptoms continue months beyond this window, and pPCS is defined as symptoms continuing over years. These conditions are temporally related single concussive events. CTE is the hallmark condition related to RHI and remains difficult to fully characterize as it currently can only be diagnosed post-mortem. Clinical features of CTE are similar to those of pPCS with notable behavioral/mood symptoms in its earliest stages, and progression to severe cognitive decline over time. Current research has shown executive dysfunction to be a common impairment among these conditions. The difference in level of dysfunction between them, if one exists, is yet to be measured. PROPOSED PROJECT: A cross-sectional analysis of executive function in four groups. A control without history of mTBI or football exposure (Non-Football – pPCS), a second control of asymptomatic subjects with football exposure (Football – pPCS), a group of pPCS patients with non-athletic mTBI history (Non-Football + pPCS), and a group of pPCS patients with football exposure (Football + pPCS). Executive functioning will be evaluated using the BRIEF-A assessment. Results will be compared to determine if significant differences in executive functioning exist between the groups. CONCLUSIONS: With previous studies showing a correlation between CTE pathological stage, worsening executive function, and increased RHI exposure, further investigation into using executive function as a distinguishing variable between early stage CTE and pPCS is warranted. SIGNIFICANCE: Results of this study, if significant, could be applied clinically to assess risk of early stage CTE in athletes with prolonged post-concussion symptoms. If results are not significant, they may still be utilized for a better understanding of the effects of isolated mTBIs and RHI on executive functioning, and provide valuable information for ongoing longitudinal studies.

A finite element model was developed for a range of human head-sUAS impacts to provide multiple case scenarios of impact severity at two response regions of interest: global and local. The hypothesis was that for certain impact scenarios, local response injuries of the brain (frontal, parietal, occipital, temporal lobes, and cerebellum) have a higher severity level compared to global response injury, the response at the Center of Gravity (CG) of the head. This study is the first one to predict and quantify the influence of impact parameters such as impact velocity, location, offset, and angle of impact to severity of injury. The findings show that an sUAS has the potential of causing minimal harm under certain impact scenarios, while other scenarios cause fatal injuries. Additionally, results indicate that the human head’s global response as a less viable response region of interest when measuring injury severity for clinical diagnosis. It is hoped that the results from this research can be useful to assist decision making for treatments and may offer different perspectives in sUAS designs or operation environments.

CTE is a progressive neurodegenerative disease defined by p-tau lesions in characteristic locations of the brain, leading to cognitive impairment as well as mood and behavioral dysfunction. Exposure to repetitive head impacts is a major risk factor for developing CTE; however, additional risk factors and secondary modulating factors, which may expand available treatment and prevention options, are still being elucidated. Studies into the glymphatic system, a system of waste clearance in the brain thought to be activated during sleep, have implicated glymphatic dysfunction in the clearance of toxic proteins like amyloid-beta and hyperphosphorylated tau, as well as in cognitive decline in neurodegenerative disorders like Alzheimer’s Disease, bringing into question whether sleep, through impacting glymphatic clearance, may act as a modulating factor in the development of CTE. In the present study, we began to characterize the presence of sleep disorders and their co-morbid conditions in a cohort of former college football players to gain better insight into their prevalence and the health outcomes of those with sleep conditions. Our results found higher rates of sleep apnea in the study sample, as well as an association between diagnosis with sleep apnea and diagnosis with dementia, AD, MCI, CTE, and similar disorders. Sleep apnea was significantly associated with depression, anxiety, high cholesterol, and diabetes. Further research into whether sleep disorders exacerbate CTE pathology or clinical symptoms, and whether treatment of sleep symptoms leads to better outcomes for patients with CTE, is necessary to further elucidate a potential connection.