Median Time to Return to Sports After Concussion Is Within 21 Days in 80% of Published Studies.

PURPOSE: To perform a systematic review of the literature and evaluate the return to play (RTP) time frame after a concussion diagnosis. Our secondary purpose was to analyze and compare different prognostic variables affecting concussions, time to return to school, time to symptom resolution of concussive symptoms, and time each patient spent in the RTP protocol. METHODS: A PubMed, Scopus, Medline, Embase, and Cochrane Library database literature review was performed in August 2022. The studies needed to report, in days, the length of time a patient/athlete was removed from play due to concussion management. The Risk of Bias in Non-Randomized Studies of Interventions tool was used for risk of bias for each study, and Methodological Index for Non-Randomized Studies criteria were used for quality assessment. RESULTS: There were 65 studies included in the systematic review and a total of 21,966 patients evaluated. The RTP time intervals ranged from 1 to 1,820 days, with 80.7% of the median RTP time frames for each study within 21 days. Preconcussion risk factors for prolonged RTP included female sex, younger age, presence of psychiatric disorders, and history of previous concussion. Postconcussion risk factors included severe symptom scores at initial clinic visit, loss of consciousness, nonelite athletes, and delayed removal from competition. The most common sports resulting in concussion were contact sports, most commonly football and soccer. Median time to return to school was 3 to 23 days. Median time to symptom resolution ranged from 2 to 11 days. Median time in RTP protocol was 1 to 6 days. CONCLUSIONS: Median time to return to sports after concussion is within 21 days in 80% of published studies. LEVEL OF EVIDENCE: IV, systematic review of Level I to IV studies.

Cumulative strain-based metrics for predicting subconcussive head impact exposure-related imaging changes in a cohort of American youth football players.

OBJECTIVE: Youth football athletes are exposed to repetitive subconcussive head impacts during normal participation in the sport, and there is increasing concern about the long-term effects of these impacts. The objective of the current study was to determine if strain-based cumulative exposure measures are superior to kinematic-based exposure measures for predicting imaging changes in the brain. METHODS: This prospective, longitudinal cohort study was conducted from 2012 to 2017 and assessed youth, male football athletes. Kinematic data were collected at all practices and games from enrolled athletes participating in local youth football organizations in Winston-Salem, North Carolina, and were used to calculate multiple risk-weighted cumulative exposure (RWE) kinematic metrics and 36 strain-based exposure metrics. Pre- and postseason imaging was performed at Wake Forest School of Medicine, and diffusion tensor imaging (DTI) measures, including fractional anisotropy (FA), and its components (CL, CP, and CS), and mean diffusivity (MD), were investigated. Included participants were youth football players ranging in age from 9 to 13 years. Exclusion criteria included any history of previous neurological illness, psychiatric illness, brain tumor, concussion within the past 6 months, and/or contraindication to MRI. RESULTS: A total of 95 male athletes (mean age 11.9 years [SD 1.0 years]) participated between 2012 and 2017, with some participating for multiple seasons, resulting in 116 unique athlete-seasons. Regression analysis revealed statistically significant linear relationships between the FA, linear coefficient (CL), and spherical coefficient (CS) and all strain exposure measures, and well as the planar coefficient (CP) and 8 strain measures. For the kinematic exposure measures, there were statistically significant relationships between FA and RWE linear (RWEL) and RWE combined probability (RWECP) as well as CS and RWEL. According to area under the receiver operating characteristic (ROC) curve (AUC) analysis, the best-performing metrics were all strain measures, and included metrics based on tensile, compressive, and shear strain. CONCLUSIONS: Using ROC curves and AUC analysis, all exposure metrics were ranked in order of performance, and the results demonstrated that all the strain-based metrics performed better than any of the kinematic metrics, indicating that strain-based metrics are better discriminators of imaging changes than kinematic-based measures. Studies relating the biomechanics of head impacts with brain imaging and cognitive function may allow equipment designers, care providers, and organizations to prevent, identify, and treat injuries in order to make football a safer activity.

Which Sport Is More Dangerous: Ice Hockey or Field Hockey? A Review of the Head and Neck Injuries Associated With the Two Sports.

PURPOSE: Ice hockey and field hockey are contact sports with the potential for injury, especially to the head and neck regions. The purpose of this study is to estimate and compare hospital admission (injury severity) between ice hockey and field hockey of those who presented to the emergency department with head and neck injuries. METHODS: The investigators designed and implemented a 20-year retrospective cohort study using the National Electronic Injury Surveillance System database. We included data related to ice hockey and field hockey injuries from January 2000 to December 2019 in this study. The primary predictor variable was sport played (ice hockey vs field hockey). Secondary predictor variables and covariates were derived from patient and injury characteristics. The primary outcome variable was hospital admission. Logistic regression was used to determine independent risk factors for the outcome variable. RESULTS: Our final sample was composed of 5,472 patients: 4,472 patients suffered head and neck injuries from ice hockey while the remaining 1,000 patients suffered head and neck injuries from field hockey. Players less than 18 years old were associated with 2.07-fold odds of admission (P < .01). Injury to the head (odds ratio [OR] = 14.339; 95% confidence interval [CI], 2.0 to 105.1; P < .01) and neck (OR = 89.260; 95% CI, 11.2 to 712.6; P < .01) were independently associated with an increased odds of admission. Relative to contusions/abrasions, players who suffered a concussion (OR = 141.637; 95% CI, 11.5 to 1,741.5; P < .01), fracture (OR = 155.434; 95% CI, 17.0 to 1,419.2; P < .01), internal organ injury (OR = 186.450; 95% CI, 15.5 to 2,236.8; P < .01), or hematoma (OR = 23.046; 95% CI, 1.2 to 442.5; P < .05) were all independently associated with an increased odds of admission. Ice hockey was not an independent risk factor for admission relative to field hockey. CONCLUSIONS: The findings of this study suggest that ice hockey was more associated with injuries to the head and neck as well as with concussions and internal organ injury compared to field hockey. However, ice hockey was not associated with increased risk of hospitalization relative to field hockey.

First case of chronic post-traumatic anterior pituitary dysfunction in a professional rugby player: A case report.

BACKGROUND: Post-traumatic hypopituitarism has been reported as a complication in a number of contact sports. Although rugby is a sport with a high risk and high incidence of concussion, no such cases have been reported to date. CASE PRESENTATION: A 35-year-old professional rugby player presented with fatigue and reduced libido complaints after nearly 300 professional games during his 15-year career. At the end of the season, biological monitoring was performed and revealed low total testosterone level associated with a low luteinizing hormone, suggestive of central hypogonadism. Brain magnetic resonance imaging (MRI) revealed the presence of a 10-mm sequel lesion in the right medial temporal lobe and two additional punctiform lesions, all suggestive of post-traumatic brain injury lesions. Testosterone replacement therapy was initiated and the player perceived an overall decrease in fatigue and complete restoration of his libido after only a couple of weeks of treatment. During follow-up, thyrotropic deficiency was diagnosed 2 years after initial diagnosis treated by l-Thyroxin. CONCLUSIONS: In conclusion, this case report highlights a new post-traumatic brain injury complication in a professional rugby player, namely chronic post-traumatic anterior pituitary dysfunction. STUDY DESIGN: Case report; level of evidence 4.

The effect of specialization and level of competition on injury in elite male ice hockey players.

OBJECTIVE: Young players experience pressure to focus on ice hockey at the exclusion of other sports in order to improve chances of success. Early specialization in other sports has been associated with increased injury without the benefit of improved success. The objective of the current study was to investigate whether earlier specialization results in increased injury without higher rates of career success. This study also aimed to compare rates of injury in athletes at various levels of competition. METHODS: An original survey was issued to men's ice hockey players at the juniorA, collegiate, and professional levels. The survey consisted of 34 questions on various demographic, specialization, and injury variables. All participants were >18 years of age. RESULTS: The survey was completed by 101 athletes. The mean age at specialization was 13 (±4) overall and 14 (±3), 13 (±4), and 11(±4) for professional, collegiate, and junior players, respectively. There was no difference in age at specialization between each group and professional players did not specialize earlier than the remainder of the cohort as a whole (p > 0.05). There was no significant correlation between age at specialization and total injuries (p > 0.05). There was no difference in concussions causing missed play time between groups (p > 0.05) but professional players had more overall concussions and underwent more surgeries due to hockey-related injuries (p = 0.01). CONCLUSIONS: Specializing exclusively in ice hockey earlier in life was not associated with playing professionally. Both collegiate and professional players do not tend to specialize prior to age 12. Age at specialization was not associated with overall number of injuries. Professional players with longer careers appear to sustain more concussions and undergo more surgery.

Craniomaxillofacial injuries from the sport of wrestling: a query of the National Electronic Injury Surveillance System (NEISS).

PURPOSE: The purpose of this study was to provide a novel report on the head and neck injuries from the sport of wrestling and their characteristics in the USA. MATERIALS AND METHODS: This is a 20-year retrospective cross-sectional study conducted using the National Electronic Injury Surveillance System (NEISS). Reports were included in the analysis if the injury stemmed from combat with another person. The predictor variables were obtained from both patient and injury characteristics. The principal outcome variable was admission rate, which was used to proxy the severity of the injury at hand. Bivariate analysis (i.e., chi-square and independent sample tests) was used to determine if an association existed between two variables of interest. RESULTS: The final sample in our study consisted of 4485 cases of craniomaxillofacial injuries secondary to wrestling. The increase in injuries from the year 2000 to 2019 was significant (P < 0.05). The average age of patients was 15.73 (range: 3 to 59 years old). Virtually all of the injuries occurred in males (95.6%). The majority of patients was under the age of 18 (82.3%). With regard to race, white wrestlers (57.1%) comprised the majority of patients. Insight into race was not available for 1245 patients (27.8%). Most wrestling-related injuries took place during the winter season (60.6%). Concussion was the most common primary diagnosis (29.0%). The head (57.1%) was the most commonly injured craniomaxillofacial region. The most common setting in which the injury took place was a place of recreation/sports (49.9%). Among the mechanisms of injuries, the take-down (26.5%) was the most common. Patients who were thrown/taken down (5.04%) were significantly more likely to get admitted (P < 0.01) relative to patients who were injured otherwise (2.6%). Similarly, patients who fell/tripped (6.6%) were significantly more likely to get admitted (P < 0.05) relative to patients who were injured otherwise (3.1%). While cases of concussion (6.0%) were significantly more likely to get admitted (P < 0.01) relative to other cases, cases of contusions/abrasions (0.6%) were significantly less likely to get admitted (P < 0.01) relative to other cases. Similar to contusions/abrasions (0.2%), lacerations were significantly less likely to get admitted (P < 0.01) relative to other cases. Patients aged 12-18 (P < 0.01) were most likely to suffer concussions, whereas patients aged 19-34 (P < 0.01) were least likely to suffer concussions. In contrast to concussions, patients aged 12-18 (P < 0.01) were least likely to suffer lacerations, whereas patients aged 19-34 (P < 0.01) were most likely to suffer lacerations. Patients aged 6-11 (P < 0.01) were most likely to be thrown/taken-down whereas patients aged 19-34 (P < 0.01) were least likely to be thrown. Patients aged 19-34 (P < 0.01) were most likely to be collided against intentionally, while patients aged 6-11 (P < 0.01) were least likely to be collided against intentionally. Patients aged 34 years or older were most likely to fall/trip, while patients aged 12-18 (P < 0.01) were least likely to fall/trip. CONCLUSIONS: Certain types of injuries that occur during wrestling are more or less common depending on the age groups involved in the sport. Concussions were the most common injury incurred overall, and the head is the most commonly affected craniomaxillofacial area. Take-downs were the most likely mechanism of injury to lead to hospital admissions. The average number of wrestling injuries increased over 20 years being analyzed in this study. Future studies should investigate methods to lessen concussions in wrestling, decrease the number of illegal moves performed, and look into ways to mitigate harm from take-downs, given the increasing number of injuries acquired from this sport.

Correlation Between Sports-Related Maxillofacial Injuries and Head Injuries: A Five-Year Retrospective Study.

PURPOSE: As sports have become more diverse and demanding, the number of patients with a maxillofacial injury accompanied by a cranial injury or neurological symptoms has increased. This study examined the correlation between sports-related maxillofacial injuries and head injuries. PATIENTS AND METHODS: Among the patients who visited the emergency department of Pusan National University Dental Hospital due to a maxillofacial injury from sporting activities between 2014 and 2018, those who additionally had head injuries were retrospectively examined. Sporting activities were classified according to the American Academy of Pediatrics classification, and severity of injuries was determined using the Facial Injury Severity Scale (FISS). Patients whose medical records showed neurological symptoms and who underwent brain computed tomography for concomitant head injury were selected. The association between each of these variables, including age and gender, was statistically analyzed. RESULTS: A total of 95 patients were included in this study, most of whom were male teenagers, and cycling was the most common cause of injuries. The meanFISS score was 0.79. Brain computed tomography was conducted for 91 patients, and 28 patients reported neurological symptoms. Only 11 patients underwent advanced evaluation in the neurology or neurosurgery department. Most patients were diagnosed with contusion and concussion and were monitored without any treatment. CONCLUSIONS: Higher FISS values did not reflect the severity of maxillofacial and head injury. In this study, there were some patients with cranial fracture and cerebral hemorrhage with mild neurosurgical symptoms of facial trauma. Although the incidence of head trauma is not high, the necessity of wearing protective equipment cannot be overemphasized because severe trauma is permanent. Neurological signs and symptoms of patients with maxillofacial trauma should not be overlooked and require a thorough evaluation.

Ball heading and subclinical concussion in soccer as a risk factor for anterior cruciate ligament injury.

Soccer players have a high risk of anterior cruciate ligament (ACL) injury, a potentially career-ending event. ACL rupture has been linked with abnormal neuromuscular control in the lower limb. Additionally, heading the ball with the unprotected head during game play is increasingly recognized as a major source of exposure to concussive and sub-concussive repetitive head impacts. This article provides a hypothesis of potential connection of ACL injury with ball heading in soccer players. The study reviews literature sources regarding the impact of neurocognitive alterations after ball headings in ACL injuries. Poor baseline neurocognitive performance or impairments in neurocognitive performance via sleep deprivation, psychological stress, or concussion can increase the risk for subsequent musculoskeletal injury.

Protein S100B and Brain Lipid-Binding Protein Concentrations in the Serum of Recently Concussed Rugby Players.

The purpose of this study was to test the ability of serum protein S100B (S100B) and brain lipid-binding protein (BLBP) to identify athletes who sustained a sports-related concussion (SRC). Subjects included a non-athlete group, whereas the rugby players were separated into two match-control and two SRC groups. The match-control <1-h group included players undergoing venipuncture within 60-min post-match, and the match-control >1-h/<8-h group included players undergoing venipuncture between 1 and 8 h post-match; the SRC <1-h group included players undergoing venipuncture within 60-min post-SRC, and the SRC >1-h/<8-h group included players undergoing venipuncture between 1 and 8 h post-SRC. Serum S100B concentrations were not significantly different (p = 0.112) among protocols. Serum BLBP was greater in the match-control <1-h group (p < 0.001) and the SRC >1-h/<8-h group (p = 0.003) compared to the non-athlete group. The ability of serum BLBP to distinguish between SRC groups and the non-athlete group was shown to be good to excellent (AUROC, >0.8; p < 0.05), and between match-control groups and the non-athlete group were shown to be excellent (AUROC, >0.9; p < 0.05). Our results show that serum S100B is not useful in distinguishing concussed or post-match athletes from non-athletes. However, serum BLBP was shown to distinguish non-athletes from post-match or concussed athletes. Serum BLBP could not distinguish between athletes experiencing an SRC within 1 h of blood draw and those participating in a contact sport.

Utility of 1 Measurement Versus Multiple Measurements of Near Point of Convergence After Concussion.

CONTEXT: Increased near point of convergence (NPC) distance is a common finding after concussion and is associated with physical symptoms and worsened neurocognitive performance. Vestibular/Ocular Motor Screening measures NPC distance across 3 trials and uses the average measurement to inform clinical care. However, whether 3 trials are necessary, are consistent, or add clinical utility is unknown. OBJECTIVE: To investigate the consistency across 3 trials of NPC and establish the classification accuracy (ie, clinical utility) of 1 or 2 trials compared with the standardized average of 3 trials. DESIGN: Retrospective cohort study. SETTING: Sports medicine clinic and research laboratory. PATIENTS OR OTHER PARTICIPANTS: Consecutively enrolled patients aged 10 to 22 years with diagnosed concussions (74% sport related; n = 380). MAIN OUTCOME MEASURE(S): The previously reported clinical cutoff value of ≥5 cm across 3 trials was used. Pearson correlation and intraclass correlation coefficients were used to evaluate agreement between trials and average scores. Reliable change indices (RCIs) using 95% confidence intervals were also calculated. RESULTS: The Pearson correlation (r = .98) and intraclass correlation (0.98) coefficients revealed excellent agreement between the first measurement and average NPC distance across 3 measurements. The RCI across all trials was 2 cm. When the first NPC measurement was ≤3 cm or ≥7 cm, agreement existed within the RCI between the first measurement and the average of 3 measurements in 99.6% of cases. When we averaged the first and second measurements, 379/380 (99.7%) participants had the same classification (ie, <5 cm = normal, ≥5 cm = abnormal) as the average NPC distance across 3 measurements. CONCLUSIONS: Our findings suggest limited utility of multiple or average NPC distance measurements when the initial NPC distance is outside of RCI clinical cutoffs (ie, ≤3 cm or ≥7 cm). Given the high consistency between the first measurement and average NPC distance across 3 trials, only 1 measurement of NPC distance is warranted unless the first measurement is between 3 and 7 cm.

Increased Microglial Exosomal miR-124-3p Alleviates Neurodegeneration and Improves Cognitive Outcome after rmTBI.

Repetitive mild traumatic brain injury (rmTBI) is considered to be an important risk factor for long-term neurodegenerative disorders such as Alzheimer's disease, which is characterized by ß-amyloid abnormalities and impaired cognitive function. Microglial exosomes have been reported to be involved in the transportation, distribution, and clearance of ß-amyloid in Alzheimer's disease. However, their impacts on the development of neurodegeneration after rmTBI are not yet known. The role of miRNAs in microglial exosomes on regulating post-traumatic neurodegeneration was investigated in the present study. We demonstrated that miR-124-3p level in microglial exosomes from injured brain was significantly altered in the acute, sub-acute, and chronic phases after rmTBI. In in vitro experiments, microglial exosomes with upregulated miR-124-3p (EXO-124) alleviated neurodegeneration in repetitive scratch-injured neurons. The effects were exerted by miR-124-3p targeting Rela, an inhibitory transcription factor of ApoE that promotes the ß-amyloid proteolytic breakdown, thereby inhibiting ß-amyloid abnormalities. In mice with rmTBI, the intravenously injected microglial exosomes were taken up by neurons in injured brain. Besides, miR-124-3p in the exosomes was transferred into hippocampal neurons and alleviated neurodegeneration by targeting the Rela/ApoE signaling pathway. Consequently, EXO-124 treatments improved the cognitive outcome after rmTBI, suggesting a promising therapeutic strategy for future clinical translation.

Cannabis, alcohol and cigarette use during the acute post-concussion period.

Objective: To document the prevalence of acute post-concussion cannabis, alcohol and cigarette use and their association with clinical recovery and symptom burden.Methods: A prospective cohort study was conducted. Concussions were physician-diagnosed and presented to the emergency department and concussion clinic within 7 days post-injury. Participants were assessed weekly and followed for a minimum 4 weeks. A survival analysis (using physician-determined recovery to both cognitive and physical activities) in addition to a weekly symptom score analysis was conducted.Results: A total of 307 acute concussions with a mean age of 33.7 years (SD, 13.0) were included. Acute post-concussion cannabis, alcohol and cigarette use were identified in 43 (14.0%), 125 (40.7%) and 61 (19.9%) individuals. Acute cannabis, alcohol and cigarette use were not associated with recovery to cognitive (p > .05) or physical activity (p > .05). Acute cigarette use was associated with a higher unadjusted symptom severity score at week1 (p = .003). Acute cannabis use was associated with lower symptom severity scores at week-3 (p = .061) and week-4 (p = .029).Conclusion: In conclusion, cannabis, alcohol and cigarette use were prevalent in the acute period post-concussion; however, were not observed to impact recovery within the first 4 weeks post-injury. Amongst unrecovered individuals, acute cannabis use was associated with lower symptom burden, while cigarette use was associated with greater initial symptom burden.

In Vivo Protocol of Controlled Subconcussive Head Impacts for the Validation of Field Study Data.

Subconcussive hits pose a threat to neuronal health as they have shown to induce neuronal structural damage and functional impairment without causing outward symptomology and appear to be a key contributor to an irreversible neurodegenerative disease, chronic traumatic encephalopathy (CTE). In addition, athletes can incur more than 1,000 of these hits per season. The subconcussive soccer heading model (SSHM) is a relevant, reproducible, and leading method of isolating and examining the effects of these subconcussive head impacts. By controlling variables such as ball traveling speed, the frequency of impacts, interval, ball placement to the head, as well as by measuring head impact magnitude, the SSHM provides the scientific community with a superior avenue of investigating the acute subconcussive effects on neuronal health. In this paper, we demonstrate the utility of SSHM in studying a time-course expression of neurofilament-light polypeptide (NF-L) in plasma in a repeated measures fashion. NF-L is an axonal injury marker that has previously been shown to be elevated in boxers and football players following subconcussive head trauma. Thirty-four adult aged soccer players were recruited and randomly assigned to either a soccer heading (n = 18) or kicking (n = 16) group. The heading group executed 10 headers with soccer balls projected at a velocity of 25 mph over 10 min. The kicking group followed the same protocol with 10 kicks. Plasma samples were obtained before and at 0 h, 2 h, and 24 h after heading/kicking and assessed for NF-L expressions. The heading group showed a gradual increase in plasma NF-L expression and peaked at 24 h after the heading protocol, whereas the kicking group remained consistent across the time points. These results confirmed the NF-L data from clinical field studies, encouraging the use of SSHM to validate clinical subconcussion data.

Fatal Second Impact Syndrome in Rowan Stringer, A 17-Year-Old Rugby Player.

Second impact syndrome (SIS) is associated with malignant brain swelling and usually occurs in young athletes with one or more prior, recent concussions. SIS is rare and some dispute its existence. We report a case of SIS in Rowan Stringer, age 17, a rugby player who sustained a fatal brain injury despite prompt medical therapy including decompression surgery. The cause of the massive brain swelling was initially unknown. An inquest revealed Rowan's text messages to friends describing symptoms from two prior, recent rugby brain injuries, likely concussions, within 5 days of the fatal blow and confirming the diagnosis of SIS.

Therapeutic Effect of a Novel Fatty Acid Amide Hydrolase Inhibitor PF04457845 in the Repetitive Closed Head Injury Mouse Model.

Concussive traumatic brain injury (TBI) is the predominant type of brain injury in young adults and is a risk factor for the development of chronic traumatic encephalopathy and other neurodegenerative diseases late in life. Using a repetitive closed head injury mouse model, we found that treatment with PF04457845, a novel fatty acid amide hydrolase (FAAH) inhibitor that selectively elevated the brain levels of anandamide, improved locomotor function, learning, and memory in TBI mice examined by beam walk, Y-maze, and Morris water maze tests. The accumulation of microglia and astrocytes and the expression of proinflammatory cytokines, including interleukin (IL)-1ß, IL-6, and tumor necrosis factor alpha (TNF-α), in the ipsilateral TBI mouse cortex and hippocampus were significantly reduced by drug treatment. The increased expression of amyloid precursor protein (APP), phosphorylated Tau (p-Tau), phosphorylated glycogen synthase kinase 3 beta (pGSK3ß) and p35/p25 subunits and the decreased expression of the pre-synaptic proteins, synaptophysin, synaptosome-associated protein of 25 kDa (SNAP25), and cysteine string protein alpha (α-CSP), in TBI mouse brain were also normalized by PF04458745 treatment. The improved locomotor function and working memory were partially mediated by activation of both cannabinoid (CB)1 and CB2 receptors, whereas the improvement on spatial learning and memory seemed to be CB1 receptor dependent. Interestingly, the blockage of PF04457845 on the reduced expression of synaptophysin, but not SNAP25 and α-CSP, was reversed by coadministration of the CB1 receptor antagonist. These results suggest that the therapeutic effect of PF04457845 is mediated by both cannabinoid receptor dependent and independent mechanisms, and selective inhibition of FAAH possesses a great potential for the treatment of TBI.

Concentrated Conditioned Media from Adipose Tissue Derived Mesenchymal Stem Cells Mitigates Visual Deficits and Retinal Inflammation Following Mild Traumatic Brain Injury.

Blast concussions are a common injury sustained in military combat today. Inflammation due to microglial polarization can drive the development of visual defects following blast injuries. In this study, we assessed whether anti-inflammatory factors released by the mesenchymal stem cells derived from adipose tissue (adipose stem cells, ASC) can limit retinal tissue damage and improve visual function in a mouse model of visual deficits following mild traumatic brain injury. We show that intravitreal injection of 1 µL of ASC concentrated conditioned medium from cells pre-stimulated with inflammatory cytokines (ASC-CCM) mitigates loss of visual acuity and contrast sensitivity four weeks post blast injury. Moreover, blast mice showed increased retinal expression of genes associated with microglial activation and inflammation by molecular analyses, retinal glial fibrillary acidic protein (GFAP) immunoreactivity, and increased loss of ganglion cells. Interestingly, blast mice that received ASC-CCM improved in all parameters above. In vitro, ASC-CCM not only suppressed microglial activation but also protected against Tumor necrosis alpha (TNFα) induced endothelial permeability as measured by transendothelial electrical resistance. Biochemical and molecular analyses demonstrate TSG-6 is highly expressed in ASC-CCM from cells pre-stimulated with TNFα and IFNγ but not from unstimulated cells. Our findings suggest that ASC-CCM mitigates visual deficits of the blast injury through their anti-inflammatory properties on activated pro-inflammatory microglia and endothelial cells. A regenerative therapy for immediate delivery at the time of injury may provide a practical and cost-effective solution against the traumatic effects of blast injuries to the retina.

Getting Hit by Pitch in Professional Baseball: Analysis of Injury Patterns, Risk Factors, Concussions, and Days Missed for Batters.

BACKGROUND: Although batters are frequently hit by pitch (HBP) in baseball, the effect of HBP injuries remains undefined in the literature. PURPOSE: To determine the effect of HBP injuries in terms of time out of play, injury patterns resulting in the greatest time out of play, and the value of protective gear such as helmets and elbow pads. STUDY DESIGN: Descriptive laboratory study. METHODS: Based on the Major League Baseball (MLB) Health and Injury Tracking System, all injuries to batters HBP during the 2011-2015 MLB and Minor League Baseball (MiLB) seasons were identified and analyzed. Video analysis was performed on all HBP events from the 2015 MLB season. Multivariate stepwise regression analysis was utilized to determine the predictive capacity of multiple variables (velocity, pitch type, location, etc) on injury status and severity. RESULTS: A total of 2920 HBP injuries resulted in 24,624 days missed (DM) over the 5 seasons. MLB HBP injuries occurred at a rate of 1 per 2554 plate appearances (1 per 9780 pitches thrown). Mean DM per injury were 8.4 (11.7 for MLB vs 8.0 for MiLB, P < .001). Surgery was required for 3.1% of MLB injuries and 1.2% of MiLB injuries ( P = .005). The most common body regions injured were the hand/fingers (n = 638, 21.8%), head/face (n = 497, 17.0%), and elbow (n = 440, 15.7%), and there were 146 (5.0%) concussions. Injury rates and mean DM correlated with velocity in a near linear fashion. Players hit in the head/face (odds ratio, 28.7) or distal upper extremity (odds ratio, 6.4) were more likely to be injured than players HBP in other locations. Players with an unprotected elbow missed 1.7 more days (95% CI, -4.1 to 7.6) than those with an elbow protector ( P = .554) when injured after being HBP. CONCLUSION/CLINICAL RELEVANCE: Although HBP injuries occur infrequently in the course of normal play, they collectively represent a significant source of time out of play. The most common body regions injured include the hands/fingers and head/face, and batters hit in these locations are significantly more likely to be injured. After contusions, concussions were the most common injury diagnosis.

Injury mechanism of midfacial fractures in football causes in over 40% typical neurological symptoms of minor brain injuries.

PURPOSE: The injury mechanisms of midfacial fractures may be typical causes of concussion, but hardly any scientific data on midfacial injuries sustained in football are available. Head and brain trauma represent frequent injuries in athletes of different sports that require appropriate treatment by sports and trauma physicians. This study investigated the management of midfacial fractures in football and the association of such fractures with concomitant brain injury. METHODS: In a prospective cohort study lasting 24 months (2012 to 2013), midfacial injuries of football players were analysed with regard to the injury mechanisms, first aid procedures on the field, treatment and return-to-play. To analyse concomitant and potentially overlooked minor brain injuries due to the trauma, we retrospectively investigated the neurological symptoms of the study population. RESULTS: The study included 132 football players (37 semi-professionals and 95 amateurs) with midfacial fractures. The main injury mechanisms were head-to-head and head-to-elbow trauma. The mean period of return-to-play after trauma was 33.5 days, which was significantly shortened if a protective face mask was worn (mean 10.4 days earlier, p = 0.0006). Semi-professional football players returned to play earlier (p = 0.009) and more often used protective face masks (p = 0.001). 55 players (41.6%) had neurological symptoms immediately after trauma as a possible sign of concomitant minor brain injury. 5 of 132 players with concussion had been hospitalised for 24 h, but no persistent neurological symptoms were detected. CONCLUSION: In football, midfacial fractures represent moderate-to-severe injuries with time away from sports of more than 4 weeks. Over 40% of athletes with a midfacial fracture showed concomitant neurological symptoms as a sign of minor brain injury. Therefore, sports physicians and other staff supervising athletes in daily practice should be aware of the presence of neurological symptoms. LEVEL OF EVIDENCE: Level III.

Video and clinical screening of national rugby league players suspected of sustaining concussion.

PRIMARY OBJECTIVE: This study reviewed the available sideline Sport Concussion Assessment Tool-Third Edition (SCAT3) performance of players who were removed from play using the 'concussion interchange rule' (CIR), the available video footage of these incidences, and associated return to play and concussion diagnosis decisions. RESEARCH DESIGN: Descriptive, observational case series. METHODS AND PROCEDURES: Data were collected from all NRL players who used the CIR during the 2014 season. MAIN OUTCOMES AND RESULTS: Complete SCAT3 and video analysis data were available for 38 (23%) of 167 uses of the concussion interchange rule, of which 20 (52.6%) players were medically diagnosed with concussion. Those with video evidence of unresponsiveness performed more poorly on the modified Balance Error Scoring System (M-BESS; p = .04; Cohen's d = .69) and reported greater symptoms (p = .03; d = .51). Similarly, players with a vacant stare reported greater symptoms (p = .05; d = .78). Those who demonstrated three signs (unresponsiveness, vacant stare and gait ataxia) performed more poorly on the M-BESS (p = .03; d = 1.4) and reported greater symptoms than those with no observable signs (p = .03; d = 1.4). CONCLUSIONS: The SCAT3 is sensitive to the acute effects of concussion in professional athletes; however, a minority of injured athletes might go undetected by this test.

Development of a Portable Tool for Screening Neuromotor Sequelae From Repetitive Low-Level Blast Exposure.

Blast exposure is a prevalent cause of mild traumatic brain injury (mTBI) in military personnel in combat. However, it is more common for a service member to be exposed to a low-level blast (LLB) that does not result in a clinically diagnosable mTBI. Recent research suggests that repetitive LLB exposure can result in symptomology similar to symptoms observed after mTBI. This manuscript reports on the use of an Android-based smartphone application (AccWalker app) to capture changes in neuromotor functioning after blast exposure. Active duty U.S. Navy personnel (N = 59) performed a stepping-in-place task before repetitive LLB exposure (heavy weapons training), and again immediately after, 24 hours after, and 72 to 96 hours after the completion of the training. The AccWalker app revealed that there are changes in neuromotor functioning after LLB exposure (slower self-selected movement pace and increased stride time variability) in participants who experienced neurocognitive decline. These data suggest that neurocognitive and neuromotor decline can occur after repeated LLB exposure.