Head Impacts in Collegiate Rodeo Athletes: An Observational Study.

INTRODUCTION: Brain health has been a growing concern across a wide range of contact sports in the last three decades. While most of the early brain health research was focused on identifying and preventing concussions, newer research has found that an accumulation of repetitive head impacts (RHI) are more predictive of long-term brain health than the number of concussions sustained. Consequently, being able to assess RHI in sports despite the lack of outward symptoms has become paramount in promoting the long-term health of athletes. The sport of rodeo has long been regarded as one of the most dangerous contact sports. While some epidemiological research has been done on injury rates in rodeo that has largely backed up its dangerous reputation, no research has been done into RHI in rodeo athletes. METHODS: Head acceleration events (HAE) were measured in collegiate athletes competing in the "Roughstock" events of Bareback Riding, Saddle Bronc Riding and Bull Riding. HAE were recorded using impact monitoring mouthgaurds (iMG) and subsequently confirmed using video verification and submitted to statistical analysis. RESULTS: Rodeo has a high rate of HAE across all the Roughstock events. The Bull Riding experiences the highest magnitude HAE based on both linear and rotational acceleration. These events are primarily the result of the head impacting either the ground or the animal during the dismount phase of the ride. Bareback riding experiences the highest quantity of lower magnitude HAE which mainly result from whiplash-like movement of the head during the ride. CONCLUSIONS: Rodeo athletes experience a high volume of HAE that often reach concerning magnitude. A surprising amount of the HAE are the result not of impacts, but of the whiplash-like movement that is experienced during the rides.

The role of secondary imaging in children aged under 24 months with proven skull fracture on initial computed tomography scan.

To assess the clinical significance of repeated head imaging in children with minor blunt force head trauma who underwent computed tomography (CT), limited to those who exclude with very low risk of important traumatic brain injury. We conducted a retrospective cohort study of children aged under 24 months with minor head trauma who underwent repeated head imaging and initial CT scans according to the Pediatric Emergency Care Applied Research Network (PECARN) rules. We enrolled 741 children and 110 with skull fracture (SF). Of the 96 patients with SF on initial CT who received head magnetic resonance imaging (MRI) a few days later, 36 (37.5%) patients' initial CT findings revealed intracranial injury in addition to SF. The number of children who exhibited new intracranial findings on follow-up MRI among those with isolated SF without intracranial damage and those with SF and intracranial injury on initial CT was 25/60 (40.7%) and 14/36 (38.9%), respectively. Subcutaneous hematoma on arrival and intersection with the coronal suture and lines of fracture were significantly associated with new intracranial findings. Four children with SF and intracranial injury on initial CT received neurosurgical intervention. No intervention was needed for those with isolated SF. We demonstrated that a proportion of children with head trauma had new findings on follow-up MRI, particularly in those without very low risk of clinically important traumatic brain injury. Patients who exhibit new intracranial MRI findings that satisfy the PECARN rules may not require neurosurgical intervention if their initial CT finding is isolated SF.

"Navigating the risks of pediatric head trauma: the role of imaging and radiation safety".

Head trauma is a frequent cause of emergency department visits in children due to their larger head-to-body ratio and developing motor skills. Younger children, especially those under 2 years, are at increased risk for skull fractures due to thinner cranial bones. Accurate diagnosis of pediatric skull fractures often requires imaging, including CT scans, which raise concerns about radiation exposure and its associated long-term risks, such as radiation-induced cancers. A recent study by Ono et al. highlights the necessity of follow-up imaging in children under 24 months with isolated skull fractures (ISF) initially detected by CT. The study found that follow-up MRI scans revealed new intracranial findings in 40.6% of cases, with some requiring neurosurgical intervention. This underscores the importance of follow-up imaging in pediatric head trauma management. However, repeated imaging, particularly CT scans, increases radiation exposure, necessitating strategies to minimize it. Novel approaches like artificial intelligence (AI) are showing promise in reducing radiation doses by enhancing scan planning, patient positioning, and improving the quality of low-dose images. Despite the study's significant findings, limitations such as its retrospective design, potential selection bias, and single-institution setting restrict generalizability. Future research should adopt prospective designs, include broader case ranges, and involve multiple centers to validate findings. In conclusion, while timely imaging is crucial for managing pediatric head trauma, balancing diagnostic accuracy with reducing radiation exposure is essential. Advances in AI present promising avenues for enhancing safety in pediatric imaging.

Artificial intelligence in paediatric head trauma: enhancing diagnostic accuracy for skull fractures and brain haemorrhages.

Pediatric head trauma is a significant cause of morbidity and mortality, with children, particularly those under two years old, being more susceptible to skull fractures due to their unique physiological and developmental characteristics. A recent study by Azusa Ono et al. examined the impact of repeated imaging in children under 24 months with minor head trauma, revealing that 40.6% of those who underwent follow-up MRI after an initial CT scan showed new intracranial findings. The study emphasizes the importance of careful consideration of repeated imaging based on initial findings and associated risk factors, such as the presence of subcutaneous hematoma and fractures intersecting coronal sutures. This underscores the need for improved diagnostic approaches to minimize radiation exposure while ensuring accurate diagnosis.Artificial Intelligence (AI) offers a promising solution, with research indicating that AI models can significantly improve diagnostic precision, increasing accuracy from 78.1 to 85.2% and reducing errors by two to three times. Additionally, AI has demonstrated high accuracy in detecting various types of brain hemorrhages, potentially facilitating earlier and more precise detection of hematomas associated with skull fractures. Integrating AI into diagnostic practices could enhance early detection, reduce diagnostic errors, and improve outcomes for pediatric head trauma cases. The study underscores the critical need for advanced diagnostic methods to better manage and treat head injuries in young children, where timely and accurate diagnosis is crucial.

Traumatic middle meningeal arteriovenous fistulas (MMAVFs): an exploratory systematic review.

This study aims to systematically review case reports and case series in order to compare the postoperative course of conservative, endovascular and surgical treatments for traumatic dural arteriovenous fistulas predominantly supplied by the middle meningeal artery (MMAVFs), which usually occur following head trauma or iatrogenic causes. We conducted a comprehensive search of PubMed, Embase, Scopus, Web of Science, and Google Scholar until June 23rd, 2024. Three cohorts were defined based on the treatment modality employed. The primary outcomes were the rates of overall obliteration and postoperative complications, with all-cause mortlality considered as secondary outcome. A total of 61 studies encompassing 78 pooled MMAVFs were included in the qualitative analysis. The predominant demographic consisted of males (53.9%) with a median age of 50.5 (IQR: 33.5-67.5) years. The main etiologies for fistula formation were head trauma (75.6%), cranial neurosurgical procedures (11.5%) and endovascular embolization (8.97%). Venous drainage patterns were categorized as follows based on anatomical confluence: Class I (16.7%), II (14.1%), III (12.8%), IV (14.1%), V (7.7%), and VI (3.9%). Regarding treatment efficacy, the overall obliteration rate was 89.74%, achieved through endovascular (95.83%), surgical (64.29%) or conservative (93.75%) approaches. In terms of safety, the overall postoperative complication rate was 6.49% with an all-cause mortality rate of 8.97%, predominantly observed in the surgical group (35.71%). Our systematic review highlights the challenging management of traumatic MMAVFs, frequently associated with head injuries. Endovascular therapy has emerged as the predominant treatment modality, demonstrating markedly higher rates of fistula obliteration, reduced all-cause mortality, and fewer postoperative complications.

Traumatic encephalocele in the nasal cavity after 6 years of trauma: a case report.

BACKGROUND: Encephalocele refers to protrusion of the meninges and brain tissue through a skull bone defect. It results from congenital, traumatic, neoplastic, or spontaneous reasons. Traumatic encephalocele occurs because of the posttraumatic fracture of the skull bone or iatrogenic causes. The manifestations vary a lot, such as rhinorrhea, seizures, headaches, and focal neurological deficits. CASE PRESENTATION: A 20-year-old Syrian male presented to our department with the complaint of clear cerebrospinal fluid drainage from his right nostril, which started 6 years ago after a head trauma, moderate headache, and episodes of tonic-clonic seizures without any response to medical treatment. Then, 2 months ago, the patient had meningoencephalitis, so he was admitted to the intensive care unit and treated for a month until he was cured. The patient underwent radiological investigations, which showed that he had a base fracture with an encephalocele in the nasal cavity. The brain tissues with the meninges herniated through the skull base fracture with a significant expansion of the subarachnoid spaces in the right hemisphere. He was advised to undergo surgical repair at that time, but he refused the surgery. During this visit, surgery was indicated. The surgery was done by a specialist who returned the herniated brain tissues to their normal location, repaired the meninges, and reconstructed the skull base with bone cement and bio-glue. The patient's recovery after the surgery was uneventful. CONCLUSION: Traumatic encephalocele is a rare and unexpected complication of trauma, but we should keep it in mind when the patient comes with head trauma because of its life-threatening consequences. This complication can happen after years of trauma if the patient refuses treatment, therefore, we must educate patients about the dangerous results of neglecting cerebrospinal fluid leakage and skull fractures.

Repetitive head-injury exposure and later-in-life cognitive and emotional outcomes among former collegiate football players: a CLEAATS investigation.

This study measured the relationship between head-injury exposure and later-in-life cognitive and emotional symptoms in aging collegiate football players who participated in the College Level Aging Athlete Study. Linear regressions examined the relationship between various head-injury exposure variables (head-injury exposure estimate [HIEE], number of diagnosed concussions, and symptomatic hits to the head) and subjective cognitive function, objective cognitive function, and emotional/mood symptoms. Additional regressions evaluated the impact of emotional symptoms on subjective cognitive decline and objective cognitive function. Participants (n = 216) were 50-87 years old (M = 63.4 [8.5]), 91% White, and well-educated (bachelor's/graduate degree = 92%). HIEE did not predict scores on cognitive or emotional/mood symptom measures (p's > .169). Diagnosed concussions had a small effect on depression symptoms (p = .002, b = 0.501, R2 = .052) and subjective cognitive symptoms (p = .002, b = 0.383, R2 = .051). An emotional symptom index had a stronger relationship (p < .001, b = 0.693, R2 = .362) with subjective cognitive functioning but no significant relationship with objective cognitive function (p = .052, b = -0.211, R2 = .020). Controlling for emotional symptoms, the relationship between concussions and subjective cognitive symptoms was attenuated (p = .078, R2 = .011). Findings suggested that head-injury exposure was not significantly related to cognitive or emotional/mood outcomes in former collegiate football players and highlighted the importance of current emotional/mood symptoms on subjective cognitive function.

Impact of cranioskeletal trauma on the development of endogenous intoxication syndrome in rats of different ages.

OBJECTIVE: Aim: The aim of the study was to determine the impact of cranioskeletal trauma (CST) on the development of endogenous intoxication syndrome in rats of different ages. PATIENTS AND METHODS: Materials and Methods: The experiments involved 147 white male Wistar rats of different age groups. The first experimental group included sexual immature rats aged 100-120 days. The second group includes sexually mature rats aged 6-8 months. The third group included old rats aged 19-23 months. In all experimental groups, CST was modelled under thiopentalonatrium anaesthesia. The control rats were only injected with thiopentalonatrium anaesthesia. The animals were withdrawn from the experiments under anaesthesia after 1, 3, 7, 14, 21 and 28 days by total bleeding from the heart. In blood serum, the content of fractions of molecules of middle mass was determined at a wavelength of 254 and 280 nm (MMM254, MMM280). RESULTS: Results: As a result application of CST in rats of different age groups, an increase in the serum content of MMM254 and MMM280 was observed with a maximum after 14 days and a subsequent decrease by 28 days. At all times of the experiment, the indicators were statistically significantly higher compared to the control groups. The degree of growth of the MMM254 fraction after 1, 7 and 14 days was statistically significantly higher in sexual immature rats, and after 21 and 28 days - in old rats. In old rats after 21 and 28 days of the post-traumatic period, the content and degree of growth of the MMM280 fraction in the blood serum were also significantly higher. CONCLUSION: Conclusions: Modelling of CST in rats of different age groups is accompanied by the development of endogenous intoxication syndrome, which is manifested by the accumulation of MMM254 and MMM280 fractions in the blood serum with a maximum after 14 days of the experiment. The content of the serum fraction of MMM254 in sexual immature rats in the dynamics of experimental CST exceeds other age groups after 1, 7 and 14 days, in old rats the content of the studied MMM fractions is significantly higher after 21-28 days.

Concomitant head or neck injury increases risk of traumatic brain injury in facial fracture patients.

Concomitant traumatic brain injury (TBI) is common in facial fracture patients and prompt intervention is crucially important to minimise the risk of potential long-term sequalae. In order to achieve rapid diagnosis, clinicians need to be aware of the risk factors associated with concomitant TBI and facial fractures. Previous literature suggests that a facial fracture can be considered a significant indicator of TBI. Nevertheless, a large data gap remains on specific injury patterns of facial fractures and associated TBI. Therefore, the objective of this study was to estimate and compare the frequency of and risk factors for TBI in patients with and without different types of additional injuries. The retrospective cohort study included 1836 facial fracture patients aged at least 18 years. The outcome variable was TBI with radiological findings in computed tomography or magnetic resonance imaging. The primary predictor variables were associated injury outside the head and neck, associated cranial fracture and associated neck injury. Based on this study, associated cranial fracture increased the risk of TBI 4.7-fold. Patients with associated neck injury had a 2.1-fold risk of TBI. In addition, significant predictors for TBI were increasing age (p = 0.0004), high energy of injury (p < 0.0001) and anticoagulant medication (p = 0.0003). Facial fracture patients with associated injuries in the head and neck region are at significant risk of TBI. In clinical work, multiprofessional evaluation of facial fracture patients should be routine and repeated survey should be targeted especially at high-risk patients to identify TBIs.

A challenging decision for emergency physicians: Routine repeat computed brain tomography of the brain in head trauma in infants and neonates.

BACKGROUND: Head trauma is a leading cause of death and disability. While standard treatment protocols exist for severe head trauma, no clear follow-up standards are available for mild head trauma with positive imaging findings in infants and newborns. Although routine follow-up brain computed tomography (CT) imaging is not recommended for children with moderate and mild head trauma, the necessity for follow-up imaging in infants and newborns remains uncertain. METHODS: Our study is a retrospective, observational, and descriptive study. Infants under 1 year old presenting to the emergency department with isolated head trauma were reviewed with the approval of the Ethics Committee of Ankara Etlik City Hospital. Inclusion criteria included presentation to the emergency department, undergoing more than one brain CT scan, and sustaining mild head trauma (Glasgow Coma Scale [GCS] >13). Patients with incomplete follow-up data or multiple traumas were excluded. Age, gender, mechanism of trauma, initial and follow-up brain CT findings, hospital admission, and surgical procedures were recorded and analyzed using the SPSS statistical package. RESULTS: Out of 238 screened patients, 154 were included in the study. Of these, 66.9% were male and the average age was 5.99 months. The most common presenting symptom was swelling at the trauma site, observed in 79.2% of cases. The most common mechanism of injury was falling from a height of less than 90 cm, accounting for 85.1% of cases. Pathological progression on follow-up CT was observed in 5.2% of the patients, and only 1.9% required surgical treatment. A total of 34.4% of the patients required hospitalization. Patients with parenchymal brain pathology had a higher rate of pathological progression on follow-up CT and a longer hospital stay. CONCLUSION: Follow-up CT scans in infants with mild head trauma do not alter patient outcomes except in cases with brain parenchymal pathology. Study data indicated that repeat imaging is not beneficial for isolated skull fractures. Imaging artifacts often necessitated repeated scans, contributing to increased radiation exposure. Unnecessary repeat imaging escalates radiation exposure and healthcare costs. Only a small percentage of patients exhibited progression of intracranial pathology, justifying follow-up imaging solely in the presence of brain parenchymal injury. Larger prospective studies are necessary to confirm these findings.

The value of serum PCT/ALB and CRP/ALB ratios in evaluating the condition and prognosis of craniocerebral trauma.

INTRODUCTION: The aim of the study was to explore the value of serum procalcitonin to albumin (PCT/ALB) and C-reactive protein to albumin (CRP/ALB) ratios in evaluating the condition and prognosis of craniocerebral trauma (CT). MATERIAL AND METHODS: 158 patients with CT admitted to the emergency department of our hospital from January 2020 to June 2022 were selected as the study subjects. According to the Glasgow coma scale (GCS) score, 158 patients with CT were grouped in a mild group (GCS score 13-15 points, n = 68), a moderate group (GCS score 9-12 points, n = 61), and a severe group (GCS score 3-8 points, n = 29). Besides, according to the patient's Glasgow prognosis (GOS) score, 158 patients with CT were divided into a good prognosis group (GOS score 4-5 points, n = 110) and a poor prognosis group (GOS score 1-3 points, n = 48). Serum PCT/ALB and CRP/ALB levels of different groups were compared. The correlation between PCT/ALB and CRP/ALB ratios and the score of GCS and GOS was explored using Pearson correlation analysis. Prognosis-related influencing factors were found out through multivariate logistic regression. The value of serum PCT/ALB and CRP/ALB ratios in evaluating the condition and prognosis of CT was evaluated by the ROC curve. RESULTS: Patients in the moderate and severe groups had much higher ratios of PCT/ALB and CRP/ALB and sharply lower GCS scores than those in the mild group ( p < 0.001). Compared with the patients in the moderate group, those in the severe group had much higher PCT/ALB and CRP/ALB ratios and obviously lower GCS scores ( p < 0.001). Patients with poor prognosis had markedly higher PCT/ALB and CRP/ALB ratios and memorably lower GOS score than the patients with good prognosis ( p < 0.001). A negative correlation between PCT, CRP, PCT/ALB ratio, CRP/ALB ratio and GCS scores ( r = -0.821, -0.857, -0.750, -0.766, p < 0.001) and GOS scores ( r = -0.636, -0.628, -0.595, -0.628, p < 0.001) was revealed by Pearson correlation analysis. ALB was correlated positively with GCS score and GOS score ( r = 0.381, 0.413, p < 0.001). Multivariate logistic regression analysis exhibited that PCT/ALB ratio and CRP/ALB ratio were related to poor prognosis of CT patients ( p < 0.05). ROC curve analysis showed that the combined PCT/ALB ratio and CRP/ALB area under the curve (AUC) were 0.883 and 0.860, respectively, which were used to assess the severity and predict prognosis of patients with CT. CONCLUSIONS: PCT/ALB and CRP/ALB ratios were positively correlated with the severity and prognosis of patients with CT, and were risk factors for poor prognosis. Early determination of changes in PCT/ALB and CRP/ALB ratios had a certain clinical value for evaluating the condition and prognosis of CT patients.

Pediatric head injury guideline use in Sweden: a cross-sectional survey on determinants for successful implementation of a clinical practice guideline.

BACKGROUND: The Scandinavian Neurotrauma Committee guideline (SNC-16) was developed and published in 2016, to aid clinicians in management of pediatric head injuries in Scandinavian emergency departments (ED). The objective of this study was to explore determinants for use of the SNC-16 guideline by Swedish ED physicians. METHODS: This is a nationwide, cross-sectional, web-based survey in Sweden. Using modified snowball sampling, physicians managing children in the ED were invited via e-mail to complete the validated Clinician Guideline Determinants Questionnaire between February and May, 2023. Baseline data, data on enablers and barriers for use of the SNC-16 guideline, and preferred routes for implementation and access of guidelines in general were collected and analyzed descriptively and exploratory with Chi-square and Fisher's tests. RESULTS: Of 595 invitations, 198 emergency physicians completed the survey (effective response rate 33.3%). There was a high reported use of the SNC-16 guideline (149/195; 76.4%) and a strong belief in its benefits for the patients (188/197; 95.4% agreement). Respondents generally agreed with the guideline's content (187/197; 94.9%) and found it easy to use and navigate (188/197; 95.4%). Some respondents (53/197; 26.9%) perceived a lack of organizational support needed to use the guideline. Implementation tools may be improved as only 58.9% (116/197) agreed that the guideline includes such. Only 37.6% (74/197) of the respondents agreed that the guideline clearly describes the underlying evidence supporting the recommendation. Most respondents prefer to consult colleagues (178/198; 89.9%) and guidelines (149/198; 75.3%) to gain knowledge to guide clinical decision making. Four types of enablers for guideline use emerged from free-text answers: ease of use and implementation, alignment with local guidelines and practice, advantages for stakeholders, and practicality and accessibility. Barriers for guideline use were manifested as: organizational challenges, medical concerns, and practical concerns. CONCLUSIONS: The findings suggest high self-reported use of the SNC-16 guideline among Swedish ED physicians. In updated versions of the guideline, focus on improving implementation tools and descriptions of the underlying evidence may further facilitate adoption and adherence. Measures to improve organizational support for guideline use and involvement of patient representatives should also be considered.

Incidence and outcomes of delayed intracranial hemorrhage: a population-based cohort study.

Head trauma is a common reason for emergency department (ED) visits. Delayed intracranial hemorrhage (ICH) in patients with minor head trauma is a major concern, but controversies exist regarding the incidence of delayed ICH and discharge planning at the ED. This study aimed to determine the incidence of delayed ICH in adults who developed ICH after a negative initial brain computed tomography (CT) at the ED and investigate the clinical outcomes for delayed ICH. This nationwide population cohort study used data from the National Health Insurance Service of Korea from 2013 to 2019. Adult patients who presented to an ED due to trauma and were discharged after a negative brain CT examination were selected. The main outcomes were the incidence of ICH within 14 days after a negative brain CT at initial ED visit and the clinical outcomes of patients with and without delayed ICH. The study patients were followed up to 1 year after the initial ED discharge. Cox proportional hazard regression analysis was used to estimate the hazard ratio for all-cause 1-year mortality of delayed ICH. During the 7-year study period, we identified 626,695 adult patients aged 20 years or older who underwent brain CT at the ED due to minor head trauma, and 2666 (0.4%) were diagnosed with delayed ICH within 14 days after the first visit. Approximately two-thirds of patients (64.3%) were diagnosed with delayed ICH within 3 days, and 84.5% were diagnosed within 7 days. Among the patients with delayed ICH, 71 (2.7%) underwent neurosurgical intervention. After adjustment for age, sex, Charlson Comorbidity Index, and insurance type, delayed ICH (adjusted hazard ratio, 2.15; 95% confidence interval, 1.86-2.48; p < 0.001) was significantly associated with 1-year mortality. The incidence of delayed ICH was 0.4% in the general population, with the majority diagnosed within 7 days. These findings suggest that patient discharge education for close observation for a week may be a feasible strategy for the general population.

Adverse impact of female reproductive signaling on age-dependent neurodegeneration after mild head trauma in Drosophila.

Environmental insults, including mild head trauma, significantly increase the risk of neurodegeneration. However, it remains challenging to establish a causative connection between early-life exposure to mild head trauma and late-life emergence of neurodegenerative deficits, nor do we know how sex and age compound the outcome. Using a Drosophila model, we demonstrate that exposure to mild head trauma causes neurodegenerative conditions that emerge late in life and disproportionately affect females. Increasing age-at-injury further exacerbates this effect in a sexually dimorphic manner. We further identify sex peptide signaling as a key factor in female susceptibility to post-injury brain deficits. RNA sequencing highlights a reduction in innate immune defense transcripts specifically in mated females during late life. Our findings establish a causal relationship between early head trauma and late-life neurodegeneration, emphasizing sex differences in injury response and the impact of age-at-injury. Finally, our findings reveal that reproductive signaling adversely impacts female response to mild head insults and elevates vulnerability to late-life neurodegeneration.

Clinical implications of head trauma in frontotemporal dementia and primary progressive aphasia.

BACKGROUND: Traumatic brain injury (TBI) and repetitive head impacts (RHI) have been linked to increased risk for multiple types of neurodegenerative disease, higher dementia risk, and earlier age of dementia symptom onset, suggesting transdiagnostic implications for later-life brain health. Frontotemporal dementia (FTD) and primary progressive aphasia (PPA) represent a spectrum of clinical phenotypes that are neuropathologically diverse. FTD/PPA diagnoses bring unique challenges due to complex cognitive and behavioral symptoms that disproportionately present as an early-onset dementia (before age 65). We performed a detailed characterization of lifetime head trauma exposure in individuals with FTD and PPA compared to healthy controls to examine frequency of lifetime TBI and RHI and associated clinical implications. METHODS: We studied 132 FTD/PPA (age 68.9 ± 8.1, 65% male) and 132 sex-matched healthy controls (HC; age 73.4 ± 7.6). We compared rates of prior TBI and RHI (contact/collision sports) between FTD/PPA and HC (chi-square, logistic regression, analysis of variance). Within FTD/PPA, we evaluated associations with age of symptom onset (analysis of variance). Within behavioral variant FTD, we evaluated associations with cognitive function and neuropsychiatric symptoms (linear regression controlling for age, sex, and years of education). RESULTS: Years of participation were greater in FTD/PPA than HC for any contact/collision sport (8.5 ± 6.7yrs vs. 5.3 ± 4.5yrs, p = .008) and for American football (6.2yrs ± 4.3yrs vs. 3.1 ± 2.4yrs; p = .003). Within FTD/PPA, there were dose-dependent associations with earlier age of symptom onset for TBI (0 TBI: 62.1 ± 8.1, 1 TBI: 59.9 ± 6.9, 2 + TBI: 57.3 ± 8.4; p = .03) and years of American football (0yrs: 62.2 ± 8.7, 1-4yrs: 59.7 ± 7.0, 5 + yrs: 55.9 ± 6.3; p = .009). Within bvFTD, those who played American football had worse memory (z-score: -2.4 ± 1.2 vs. -1.4 ± 1.6, p = .02, d = 1.1). CONCLUSIONS: Lifetime head trauma may represent a preventable environmental risk factor for FTD/PPA. Dose-dependent exposure to TBI or RHI influences FTD/PPA symptom onset and memory function in bvFTD. Clinico-pathological studies are needed to better understand the neuropathological correlates linking RHI or TBI to FTD/PPA onset and symptoms.

Comparison of sample materials for S100b analysis.

Head injury is a potentially lethal and frequently occurring condition in the emergency department (ED). Reliable and fast diagnosis is important both for patients and flow in the ED. Circulating S100B is used to rule out the need for head computer tomography in low-risk patients with mild head injury. The flow of these patients through the ED would benefit from shorter turn-around time. Standard serum clotting tubes require 30-60 min clotting time, followed by an analysis time of 45 min. Here, we evaluated the performance of two alternative blood collection tubes; a rapid serum tube (RST) with a recommend clotting time of 5 min and a hirudin tube (HIR) for instant anticoagulation. S100B measurement was performed on paired blood samples from 221 subjects using a Roche Cobas 602 analyser. The performances of the alternative tubes were evaluated by method comparison to the standard serum clotting tube, repeatability and agreement of results obtained from alternative tubes compared with the standard clotting tube. Both alternative tubes had a minor positive bias (RST = 0.011 µg/L, HIR = 0.008 µg/L). The repeatability was 2% for RST and 10% for HIR, while being 4% for the standard clotting tube. In the agreement analysis, the positive and negative predictive values for RST were 62% and 100% while being 73% and 99% for HIR respectively. Our study suggests that RST is a feasible alternative to reduce laboratory turn-around time in S100b analysis.