Faculty Bibliography

Background: Chronic spinal cord injury (SCI) portends a low probability of recovery, especially in the most severe subset of motor-complete injuries. Active spinal cord stimulation with or without intensive locomotor training has been reported to restore movement after traumatic SCI. Only three cases have been reported where participants developed restored volitional movement with active stimulation turned off after a period of chronic stimulation and only after intensive rehabilitation with locomotor training. It is unknown whether restoration of movement without stimulation is possible after stimulation alone. Objective: We describe the development of spontaneous volitional movement (SVM) without active stimulation in a subset of participants in the Epidural Stimulation After Neurologic Damage (ESTAND) trial, in which locomotor training is not prescribed as part of the study protocol, and subject's rehabilitation therapies are not modified. Methods: Volitional movement was evaluated with the Brain Motor Control Assessment using sEMG recordings and visual examination at baseline and at follow-up visits with and without stimulation. Additional functional assessment with a motor-assisted bicycle exercise at follow-up with and without stimulation identified generated work with and without effort. Results: The first seven participants had ASIA Impairment Scale (AIS) A or B thoracic SCI, a mean age of 42 years, and 7.7 years post-injury on average. Four patients developed evidence of sustained volitional movement, even in the absence of active stimulation after undergoing chronic epidural spinal cord stimulation (eSCS). Significant increases in volitional power were found between those observed to spontaneously move without stimulation and those unable (p < 0.0005). The likelihood of recovery of spontaneous volitional control was correlated with spasticity scores prior to the start of eSCS therapy (p = 0.048). Volitional power progressively improved over time (p = 0.016). Additionally, cycling was possible without stimulation (p < 0.005). Conclusion: While some SVM after eSCS has been reported in the literature, this study demonstrates sustained restoration without active stimulation after long-term eSCS stimulation in chronic and complete SCI in a subset of participants. This finding supports previous studies suggesting that "complete" SCI is likely not as common as previously believed, if it exists at all in the absence of transection and that preserved pathways are substrates for eSCS-mediated recovery in clinically motor-complete SCI. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03026816.

Background/UNASSIGNED:As football comes under greater scrutiny because of concussions and other injuries, many people are searching for safer alternatives, especially for youth athletes. The injury rate in TackleBar football, one such alternative, is not currently known. Purpose/UNASSIGNED:To describe TackleBar football and calculate its injury rate over a single season to compare it with both traditional tackle and flag football. Study Design/UNASSIGNED:Descriptive epidemiology study. Methods/UNASSIGNED:TackleBar football was described, and injuries of male athletes (age range, 9-14 years) participating in TackleBar football were tracked over the course of a season (August 5 through October 27, 2018) and compared with published injury rates for traditional tackle and flag football. Results/UNASSIGNED:The overall injury rate of TackleBar football was found to be 0.31 per 1000 athlete-exposures (AEs), which is lower than youth tackle (2.25-2.60/1000 AEs) and flag (5.77/1000 AEs) football. Conclusion/UNASSIGNED:TackleBar football may represent a reasonable alternative to tackle and flag football with regard to injuries.

Epidural Spinal Cord Stimulation (eSCS) in combination with extensive rehabilitation has been reported to restore volitional movement in a select group of subjects after motor-complete spinal cord injury (SCI). Numerous questions about the generalizability of these findings to patients with longer term SCI have arisen, especially regarding the possibility of restoring autonomic function. To better understand the effect of eSCS on volitional movement and autonomic function, two female participants five and ten years after injury at ages 48 and 52 respectively with minimal spinal cord preservation on MRI were implanted with an eSCS system at the vertebral T12 level. We demonstrated that eSCS can immediately restore volitional movement in two female participants in their fifth and sixth decade of life with motor and sensory-complete SCI, five and ten years after sustaining severe radiographic injuries, and without prescribed or significant prehabilitation. Both patients experienced significant improvements in surface EMG power during a volitional control task with eSCS on. Cardiovascular function was also restored with eSCS in one participant with cardiovascular dysautonomia using specific eSCS settings during tilt challenge while not affecting function in a participant with normal cardiovascular function. Orgasm was achieved for the first time since injury in one participant with and immediately following eSCS. Bowel-bladder synergy improved in both participants while restoring volitional urination in one with eSCS. While numerous questions remain, the ability to restore some supraspinal control over motor function below the level of injury, cardiovascular function, sexual function, and bowel and bladder function should promote intense efforts to investigate and develop optimization strategies to maximize recovery in all participants with chronic SCI.

OBJECTIVE:Traumatic brain injuries (TBIs) are largely underdiagnosed and may have persistent refractory consequences. Current assessments for acute TBI are limited to physical examination and imaging. Biomarkers such as glial fibrillary acidic protein (GFAP), ubiquitin C-terminal hydrolase L1 (UCH-L1), and S100 calcium-binding protein B (S100B) have shown predictive value as indicators of TBI and potential screening tools. METHODS:In total, 37 controls and 118 unique trauma subjects who received a clinically ordered head computed tomography (CT) in the emergency department of a level 1 trauma center were evaluated. Blood samples collected at 0-8 hours (initial) and 12-32 hours (delayed) postinjury were analyzed for GFAP, UCH-L1, and S100B concentrations. These were then compared in CT-negative and CT-positive subjects. RESULTS:Median GFAP, UCH-L1, and S100B concentrations were greater in CT-positive subjects at both timepoints compared with CT-negative subjects. In addition, median UCH-L1 and S100B concentrations were lower at the delayed timepoint, whereas median GFAP concentrations were increased. As predictors of a positive CT of the head, GFAP outperformed UCH-L1 and S100B at both timepoints (initial: 0.89 sensitivity, 0.62 specificity; delayed: 0.94 sensitivity, 0.67 specificity). GFAP alone also outperformed all possible combinations of biomarkers. CONCLUSIONS:GFAP, UCH-L1, and S100B demonstrated utility for rapid prediction of a CT-positive TBI within 0-8 hours of injury. GFAP exhibited the greatest predictive power at 12-32 hours. Furthermore, these results suggest that GFAP alone has greater utility for predicting a positive CT of the head than UCH-L1, S100B, or any combination of the 3.

OBJECTIVE:To explore the effect of 23.4% hypertonic saline for management of elevated intracranial pressure in children admitted to our institution for severe traumatic brain injury. DESIGN/METHODS:Single-center, retrospective medical chart analysis. SETTING/METHODS:A PICU at a level 1 pediatric trauma center in the United States. PATIENTS/METHODS:Children admitted for severe traumatic brain injury from 2006 to 2016 who received 23.4% hypertonic saline and whose intracranial pressures were measured within 5 hours of receiving 23.4% hypertonic saline. INTERVENTIONS/METHODS:None. MEASUREMENTS AND MAIN RESULTS/RESULTS:Over the 10-year period, 1,587 children were admitted for traumatic brain injury, 155 of whom were deemed severe per this study's criteria. Forty of these children received at least one dose of hypertonic saline, but 14 were excluded for insufficient intracranial pressure data. Among the remaining 26 children, one hundred one 23.4% hypertonic saline boluses were used in the analysis. Use of 23.4% hypertonic saline was associated with a decrease in intracranial pressure of approximately 7 mm Hg at both within 1 hour after the bolus (p < 0.01) and 4 hours after the bolus (p < 0.01) when compared with the intracranial pressure measured within 1 hour before the hypertonic saline bolus. These effects remained significant after adjusting for Functional Status Scale score and CT Marshall scores. There was no statistically significant association between adjunctive therapies, such as antiepileptics and analgesics, and changes in intracranial pressure. There was no laboratory evidence of hyperkalemia or renal injury after use of 23.4% hypertonic saline. Across all hospitalizations, 65% of the study population demonstrated an abnormally elevated creatinine at least once, but only three episodes of acute kidney injury occurred in total, all before hypertonic saline administration. Eight of the 26 children in this analysis died during their hospitalization. The Functional Status Scale scores ranged from 6 to 26 with a mean of 12.2 and SD of 5.7. CONCLUSIONS:Use of 23.4% hypertonic saline with children admitted for severe traumatic brain injury is associated with a statistically significant decrease in intracranial pressure within 1 hour of use.

OBJECTIVE Chronic subdural hematoma (cSDH) is a highly morbid condition associated with brain atrophy in the elderly. It has a reported 30% 1-year mortality rate. Approximately half of afflicted individuals report either no or relatively unremarkable trauma preceding their diagnosis, raising the possibility that cSDH is a manifestation of degenerative or inflammatory disease rather than trauma. The purpose of this study was to compare the rates of cerebral atrophy before and after cSDH to determine whether it is more likely that cSDH causes atrophy or that atrophy causes cSDH. The authors also compared atrophy rates in patients with cSDH to the rates in patients with and without dementia. METHODS The authors developed algorithmic segmentation analysis software to measure whole-brain, CSF, and intracranial space volumes. They then identified military veterans who had undergone at least 4 brain CT scans over a period of 10 years. Within this database, the authors identified 146 patients with 962 head CT scans who had received diagnoses of either cSDH, dementia, or no known dementia condition. Volumetric analyses of brains in 45 patients with dementia (dementia group) and 73 patients without dementia (nondementia group), in whom 262 and 519 head CT scans were obtained, respectively, were compared with 11 patients in whom 81 CT scans were obtained a mean of 4.21 years before a cSDH diagnosis and 17 patients in whom 100 scans were obtained a mean of 4.24 years after SDH. Longitudinal measures were then related to disease status and the time since first scan by using hierarchical models, and atrophy rates between the groups were compared. RESULTS Head CT scans from patients were obtained for an average time period of 4.21 years (SD 1.69) starting at a mean patient age of 74 years. Absolute brain volume loss for the 17 patients in the post-SDH group (13 were treated surgically) was significantly greater, at 16.32 ml/year, compared with 6.61 ml/year in patients with dementia, 5.33 ml/year in patients without dementia, and 3.57 ml/year in pre-SDH patients. The atrophy rate for these individuals prior to enrollment in the study was 2.32 ml/year (p = 0.001). In terms of brain volume normalized to cranial cavity size, the post-SDH group had an atrophy rate of 0.7801%/year, compared with 0.4467%/year in patients with dementia, 0.3474%/year in patients without dementia, and 0.2135%/year in the pre-SDH group. CONCLUSIONS Prior to development of a cSDH, the atrophy rates in patients who ultimately develop cSDH are similar to those of patients without dementia. After development of a cSDH, the atrophy rates increase to more than twice those of patients with dementia. Chronic subdural hematoma is thus associated with a significant increase in brain atrophy rate. These findings suggest the neurotoxic consequences of cSDH and may have implications for better understanding of the pathophysiology of cerebral atrophy and dementia.

Reporting of sports-related concussions (SRCs) has risen dramatically over the last decade, increasing awareness of the need for treatment and prevention of SRCs. To date most prevention studies have focused on equipment and rule changes to sports in order to reduce the risk of injury. However, increased neck strength has been shown to be a predictor of concussion rate. In the TRAIN study, student-athletes will follow a simple neck strengthening program over the course of three years in order to better understand the relationship between neck strength and SRCs. Neck strength of all subjects will be measured at baseline and biannually over the course of the study using a novel protocol. Concussion severity and duration in any subject who incurs an SRC will be evaluated using the Sports Concussion Assessment Tool 5th edition, a questionnaire based tool utilizing several tests that are commonly affected by concussion, and an automated eye tracking algorithm. Neck strength, and improvement of neck strength, will be compared between concussed and non-concussed athletes to determine if neck strength can indeed reduce risk of concussion. Neck strength will also be analyzed taking into account concussion severity and duration to find if a strengthening program can provide a protective factor to athletes. The study population will consist of student-athletes, ages 12-23, from local high schools and colleges. These athletes are involved in a range of both contact and non-contact sports.

OBJECTIVE Increased understanding of the consequences of traumatic brain injury has heightened concerns about youth participation in contact sports. This study investigated the prevalence of high school and collegiate contact sports play and concussion history among surgical department chairs. METHODS A cross-sectional survey was administered to 107 orthopedic and 74 neurosurgery chairs. Responses were compared to published historical population norms for contact sports (high school 27.74%, collegiate 1.44%), football (high school 10.91%, collegiate 0.76%), and concussion prevalence (12%). One-proportion Z-tests, chi-square tests, and binary logistic regression were used to analyze differences. RESULTS High school contact sports participation was 2.35-fold higher (65.3%, p < 0.001) for orthopedic chairs and 1.73-fold higher (47.9%, p = 0.0018) for neurosurgery chairs than for their high school peers. Collegiate contact sports play was 31.0-fold higher (44.7%, p < 0.001) for orthopedic chairs and 15.1-fold higher (21.7%, p < 0.001) for neurosurgery chairs than for their college peers. Orthopedic chairs had a 4.30-fold higher rate of high school football participation (46.9%, p < 0.001) while neurosurgery chairs reported a 3.05-fold higher rate (33.3%, p < 0.001) than their high school peers. Orthopedic chairs reported a 28.1-fold higher rate of collegiate football participation (21.3%, p < 0.001) and neurosurgery chairs reported an 8.58-fold higher rate (6.5%, p < 0.001) compared to their college peers. The rate at which orthopedic (42.6%, p < 0.001) and neurosurgical (42.4%, p < 0.001) chairs reported having at least 1 concussion in their lifetime was significantly higher than the reported prevalence in the general population. After correction for worst possible ascertainment bias, all results except high school contact sports participation remained significant. CONCLUSIONS The high prevalence of youth contact sports play and concussion among surgical specialty chairs affirms that individuals in careers requiring high motor and cognitive function frequently played contact sports. The association highlights the need to further examine the relationships between contact sports and potential long-term benefits as well as risks of sport-related injury.

Sport Concussion Assessment Tool version 3 (SCAT-3) is one of the most widely researched concussion assessment tools in athletes. Here normative data for SCAT3 in nonathletes are presented. The SCAT3 was administered to 98 nonathlete healthy controls, as well as 118 participants with head-injury and 46 participants with other body trauma (OI) presenting to the ED. Reference values were derived and classifier functions were built to assess the accuracy of SCAT3. The control population had a mean of 2.30 (SD = 3.62) symptoms, 4.38 (SD = 8.73) symptom severity score (SSS), and 26.02 (SD = 2.52) standardized assessment of concussion score (SAC). Participants were more likely to be diagnosed with a concussion (from among healthy controls) if the SSS > 7; or SSS 7 and headache or pressure in head present, or SSS 7 and headache or pressure in head, or SSS