Traumatic brain injury in England and Wales: prospective audit of epidemiology, complications and standardised mortality

Pharmacological inhibition of STING reduces neuroinflammation-mediated damage post-traumatic brain injury

BACKGROUND AND PURPOSE

Traumatic brain injury (TBI) remains a major public health concern worldwide with unmet effective treatment. Stimulator of interferon genes (STING) and its downstream type-I interferon (IFN) signalling are now appreciated to be involved in TBI pathogenesis. Compelling evidence have shown that STING and type-I IFNs are key in mediating the detrimental neuroinflammatory response after TBI. Therefore, pharmacological inhibition of STING presents a viable therapeutic opportunity in combating the detrimental neuroinflammatory response after TBI.

EXPERIMENTAL APPROACH

This study investigated the neuroprotective effects of the small-molecule STING inhibitor n-(4-iodophenyl)-5-nitrofuran-2-carboxamide (C-176) in the controlled cortical impact mouse model of TBI in 10- to 12-week-old male mice. Thirty minutes post-controlled cortical impact surgery, a single 750-nmol dose of C-176 or saline (vehicle) was administered intravenously. Analysis was conducted 2 h and 24 h post-TBI.

KEY RESULTS

Mice administered C-176 had significantly smaller cortical lesion area when compared to vehicle-treated mice 24 h post-TBI. Quantitative temporal gait analysis conducted using DigiGait™ showed C-176 administration attenuated TBI-induced impairments in gait symmetry, stride frequency and forelimb stance width. C-176-treated mice displayed a significant reduction in striatal gene expression of pro-inflammatory cytokines Tnf-α, Il-1β and Cxcl10 compared to their vehicle-treated counterparts 2 h post-TBI.

CONCLUSION AND IMPLICATIONS

This study demonstrates the neuroprotective activity of C-176 in ameliorating acute neuroinflammation and preventing white matter neurodegeneration post-TBI. This study highlights the therapeutic potential of small-molecule inhibitors targeting STING for the treatment of trauma-induced inflammation and neuroprotective potential.

Epidemiology, Pathophysiology, and Treatment Strategies of Concussions: A Comprehensive Review

A concussion is a particular manifestation of a traumatic brain injury, which is the leading cause of mortality and disabilities across the globe. The global prevalence of traumatic brain injury is estimated to be 939 instances per 100,000 individuals, with approximately 5.48 million people per year experiencing severe traumatic brain injury. Epidemiology varies amongst different countries by socioeconomic status with diverse clinical manifestations. Additionally, classifying concussions is an ambiguous process as clinical diagnoses are the only current classification method, and morbidity rates differ by demographic location as well as populations examined. In this article, we critically reviewed the pathophysiology of concussions, classification methods, treatment options available including both pharmacologic and nonpharmacologic intervention methods, etiologies as well as global etiologic differences associated with them, and clinical manifestations along with their associated morbidities. Furthermore, analysis of the current research regarding the incidence of concussion based traumatic brain injuries and future directions are discussed. Investigation on the efficacy of new therapeutic-related interventions such as exosome therapy and electromagnetic field stimulation are warranted to properly manage and treat concussion-induced traumatic brain injury.

Is lifetime traumatic brain injury a risk factor for mild cognitive impairment in veterans compared to non-veterans?

Background: Traumatic brain injury (TBI) is prevalent in veterans and may occur at any stages of their life (before, during, or after military service). This is of particular concern, as previous evidence in the general population has identified TBI as a strong risk factor for mild cognitive impairment (MCI), a known precursor of dementia.Objectives: This study aimed to investigate whether exposure to at least one TBI across the lifetime was a risk factor for MCI in ageing UK veterans compared to non-veterans.Method: This cross-sectional study comprised of data from PROTECT, a cohort study comprising UK veterans and non-veterans aged ≥ 50 years at baseline. Veteran and TBI status were self-reported using the Military Service History Questionnaire (MSHQ) and the Brain Injury Screening Questionnaire (BISQ), respectively. MCI was the outcome of interest, and was defined as subjective cognitive impairment and objective cognitive impairment.Results: The sample population comprised of veterans (n = 701) and non-veterans (n = 12,389). TBI was a significant risk factor for MCI in the overall sample (OR = 1.21, 95% CI 1.11-1.31) compared to individuals without TBI. The prevalence of TBI was significantly higher in veterans compared to non-veterans (69.9% vs 59.5%, p < .001). There was no significant difference in the risk of MCI between veterans with TBI and non-veterans with TBI (OR = 1.19, 95% CI 0.98-1.45).Conclusion: TBI remains an important risk factor for MCI, irrespective of veteran status. The clinical implications indicate the need for early intervention for MCI prevention after TBI.

The incidence and impact of 'Tandem Neurotrauma'

Introduction

The epidemiology and prognosis of the isolated traumatic brain injury (TBI) and spinal cord injury (SCI) are well studied. However, the knowledge of the impact of concurrent neurotrauma is very limited.

Research questions

To characterize the longitudinal incidence of concurrent TBI and SCI and to investigate their combined impact on clinical care and outcomes, compared to a comparative but isolated SCI or TBI.

Materials and methods

Data from 167,793 patients in the Trauma Audit and Research Network (TARN) registry collected in England and Wales between 2008 and 2018 were analysed. Tandem neurotrauma was defined as patients with concurrent TBI and SCI. The patient with isolated TBI or SCI was matched to the patient with tandem neurotrauma using propensity scores.

Results

The incidence of tandem neurotrauma increased tenfold between 2008 and 2018, from 0.21 to 2.21 per 100,000 person-years. Patients in the tandem neurotrauma group were more likely to require multiple surgeries, ICU admission, longer ICU and hospital LOS, higher 30-day mortality, and were more likely to be transferred to acute hospitals and rehabilitation or suffer death at discharge, compared to patients with isolated TBI. Likewise, individuals with tandem neurotrauma compared to those with isolated SCI had a higher tendency to receive more than one surgery, ICU admission, longer LOS for ICU and higher mortality either at 30-day follow-up or at discharge.

Discussion and conclusions

The incidence of tandem neurotrauma has increased steadily during the past decade. Its occurrence leads to greater mortality and care requirements, particularly when compared to TBI alone. Further investigations are warranted to improve outcomes in tandem neurotrauma.

Intramural Healthcare Consumption and Costs After Traumatic Brain Injury: A Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) Study

Traumatic brain injury (TBI) is a global public health problem and a leading cause of mortality, morbidity, and disability. The increasing incidence combined with the heterogeneity and complexity of TBI will inevitably place a substantial burden on health systems. These findings emphasize the importance of obtaining accurate and timely insights into healthcare consumption and costs on a multi-national scale. This study aimed to describe intramural healthcare consumption and costs across the full spectrum of TBI in Europe. The Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) core study is a prospective observational study conducted in 18 countries across Europe and in Israel. The baseline Glasgow Coma Scale (GCS) was used to differentiate patients by brain injury severity in mild (GCS 13-15), moderate (GCS 9-12), or severe (GCS ≤8) TBI. We analyzed seven main cost categories: pre-hospital care, hospital admission, surgical interventions, imaging, laboratory, blood products, and rehabilitation. Costs were estimated based on Dutch reference prices and converted to country-specific unit prices using gross domestic product (GDP)-purchasing power parity (PPP) adjustment. Mixed linear regression was used to identify between-country differences in length of stay (LOS), as a parameter of healthcare consumption. Mixed generalized linear models with gamma distribution and log link function quantified associations of patient characteristics with higher total costs. We included 4349 patients, of whom 2854 (66%) had mild, 371 (9%) had moderate, and 962 (22%) had severe TBI. Hospitalization accounted for the largest part of the intramural consumption and costs (60%). In the total study population, the mean LOS was 5.1 days at the intensive care unit (ICU) and 6.3 days at the ward. For mild, moderate, and severe TBI, mean LOS was, respectively, 1.8, 8.9, and 13.5 days at the ICU and 4.5, 10.1, and 10.3 days at the ward. Other large contributors to the total costs were rehabilitation (19%) and intracranial surgeries (8%). Total costs increased with higher age and greater trauma severity (mild; €3,800 [IQR €1,400-14,000], moderate; €37,800 [IQR €14,900-€74,200], severe; €60,400 [IQR €24,400-€112,700]). The adjusted analysis showed that female patients had lower costs than male patients (odds ratio (OR) 0.80 [CI 0.75-1.85]). Increasing TBI severity was associated with higher costs, OR 1.46 (confidence interval [CI] 1.31-1.63) and OR 1.67 [CI 1.52-1.84] for moderate and severe patients, respectively. A worse pre-morbid overall health state, increasing age and more severe systemic trauma, expressed in the Injury Severity Score (ISS), were also significantly associated with higher costs. Intramural costs of TBI are significant and are profoundly driven by hospitalization. Costs increased with trauma severity and age, and male patients incurred higher costs. Reducing LOS could be targeted with advanced care planning, in order to provide cost-effective care.

The Role of Microglial Exosomes and miR-124-3p in Neuroinflammation and Neuronal Repair after Traumatic Brain Injury

(1) Background: In this study, we aimed to explore the regulatory mechanism of miR-124-3p microglial exosomes, as they were previously reported to modulate neuroinflammation and promote neuronal repair following traumatic brain injury (TBI). (2) Methods: Studies investigating the impact of microglial exosomal miRNAs, specifically miR-124-3p, on injured neurons and brain microvascular endothelial cells (BMVECs) in the context of TBI were reviewed. (3) Results: Animal models of TBI, in vitro cell culture experiments, RNA sequencing analysis, and functional assays were employed to elucidate the mechanisms underlying the effects of miR-124-3p-loaded exosomes on neuroinflammation and neuronal repair. Anti-inflammatory M2 polarization of microglia, mTOR signaling suppression, and BMVECs-mediated autophagy were reported as the main processes contributing to neuroprotection, reduced blood-brain barrier leakage, and improved neurologic outcomes in animal models of TBI. (4) Conclusions: Microglial exosomes, particularly those carrying miR-124-3p, have emerged as promising candidates for therapeutic interventions in TBI. These exosomes exhibit neuroprotective effects, attenuate neuroinflammation, and promote neuronal repair and plasticity. However, further research is required to fully elucidate the underlying mechanisms and optimize their delivery strategies for effective treatment in human TBI cases.

Care pathways and factors associated with interhospital transfer to neurotrauma centers for patients with isolated moderate-to-severe traumatic brain injury: a population-based study from the Norwegian trauma registry

BACKGROUND

Systems ensuring continuity of care through the treatment chain improve outcomes for traumatic brain injury (TBI) patients. Non-neurosurgical acute care trauma hospitals are central in providing care continuity in current trauma systems, however, their role in TBI management is understudied. This study aimed to investigate characteristics and care pathways and identify factors associated with interhospital transfer to neurotrauma centers for patients with isolated moderate-to-severe TBI primarily admitted to acute care trauma hospitals.

METHODS

A population-based cohort study from the national Norwegian Trauma Registry (2015-2020) of adult patients (≥ 16 years) with isolated moderate-to-severe TBI (Abbreviated Injury Scale [AIS] Head ≥ 3, AIS Body < 3 and maximum 1 AIS Body = 2). Patient characteristics and care pathways were compared across transfer status strata. A generalized additive model was developed using purposeful selection to identify factors associated with transfer and how they affected transfer probability.

RESULTS

The study included 1735 patients admitted to acute care trauma hospitals, of whom 692 (40%) were transferred to neurotrauma centers. Transferred patients were younger (median 60 vs. 72 years, P < 0.001), more severely injured (median New Injury Severity Score [NISS]: 29 vs. 17, P < 0.001), and had lower admission Glasgow Coma Scale (GCS) scores (≤ 13: 55% vs. 27, P < 0.001). Increased transfer probability was significantly associated with reduced GCS scores, comorbidity in patients < 77 years, and increasing NISSs until the effect was inverted at higher scores. Decreased transfer probability was significantly associated with increasing age and comorbidity, and distance between the acute care trauma hospital and the nearest neurotrauma center, except for extreme NISSs.

CONCLUSIONS

Acute care trauma hospitals managed a substantial burden of isolated moderate-to-severe TBI patients primarily and definitively, highlighting the importance of high-quality neurotrauma care in non-neurosurgical hospitals. The transfer probability declined with increasing age and comorbidity, suggesting that older patients were carefully selected for transfer to specialized care.

Benchmarking short-term postoperative mortality across neurosurgery units: is hospital administrative data good enough for risk-adjustment?

BACKGROUND

Surgical mortality indicators should be risk-adjusted when evaluating the performance of organisations. This study evaluated the performance of risk-adjustment models that used English hospital administrative data for 30-day mortality after neurosurgery.

METHODS

This retrospective cohort study used Hospital Episode Statistics (HES) data from 1 April 2013 to 31 March 2018. Organisational-level 30-day mortality was calculated for selected subspecialties (neuro-oncology, neurovascular and trauma neurosurgery) and the overall cohort. Risk adjustment models were developed using multivariable logistic regression and incorporated various patient variables: age, sex, admission method, social deprivation, comorbidity and frailty indices. Performance was assessed in terms of discrimination and calibration.

RESULTS

The cohort included 49,044 patients. Overall, 30-day mortality rate was 4.9%, with unadjusted organisational rates ranging from 3.2 to 9.3%. The variables in the best performing models varied for the subspecialties; for trauma neurosurgery, a model that included deprivation and frailty had the best calibration, while for neuro-oncology a model with these variables plus comorbidity performed best. For neurovascular surgery, a simple model of age, sex and admission method performed best. Levels of discrimination varied for the subspecialties (range: 0.583 for trauma and 0.740 for neurovascular). The models were generally well calibrated. Application of the models to the organisation figures produced an average (median) absolute change in mortality of 0.33% (interquartile range (IQR) 0.15-0.72) for the overall cohort model. Median changes for the subspecialty models were 0.29% (neuro-oncology, IQR 0.15-0.42), 0.40% (neurovascular, IQR 0.24-0.78) and 0.49% (trauma neurosurgery, IQR 0.23-1.68).

CONCLUSIONS

Reasonable risk-adjustment models for 30-day mortality after neurosurgery procedures were possible using variables from HES, although the models for trauma neurosurgery performed less well. Including a measure of frailty often improved model performance.

Investigating the characteristics and correlates of systemic inflammation after traumatic brain injury: the TBI-BraINFLAMM study

INTRODUCTION

A significant environmental risk factor for neurodegenerative disease is traumatic brain injury (TBI). However, it is not clear how TBI results in ongoing chronic neurodegeneration. Animal studies show that systemic inflammation is signalled to the brain. This can result in sustained and aggressive microglial activation, which in turn is associated with widespread neurodegeneration. We aim to evaluate systemic inflammation as a mediator of ongoing neurodegeneration after TBI.

METHODS AND ANALYSIS

TBI-braINFLAMM will combine data already collected from two large prospective TBI studies. The CREACTIVE study, a broad consortium which enrolled >8000 patients with TBI to have CT scans and blood samples in the hyperacute period, has data available from 854 patients. The BIO-AX-TBI study recruited 311 patients to have acute CT scans, longitudinal blood samples and longitudinal MRI brain scans. The BIO-AX-TBI study also has data from 102 healthy and 24 non-TBI trauma controls, comprising blood samples (both control groups) and MRI scans (healthy controls only). All blood samples from BIO-AX-TBI and CREACTIVE have already been tested for neuronal injury markers (GFAP, tau and NfL), and CREACTIVE blood samples have been tested for inflammatory cytokines. We will additionally test inflammatory cytokine levels from the already collected longitudinal blood samples in the BIO-AX-TBI study, as well as matched microdialysate and blood samples taken during the acute period from a subgroup of patients with TBI (n=18).We will use this unique dataset to characterise post-TBI systemic inflammation, and its relationships with injury severity and ongoing neurodegeneration.

ETHICS AND DISSEMINATION

Ethical approval for this study has been granted by the London-Camberwell St Giles Research Ethics Committee (17/LO/2066). Results will be submitted for publication in peer-review journals, presented at conferences and inform the design of larger observational and experimental medicine studies assessing the role and management of post-TBI systemic inflammation.

Considerations for integrating wearables into the everyday healthcare practice

Wearable technologies are becoming ever more popular as suggested tools for use in modern medicine. Studies evidence their growing pragmatism and provision of objective data for a more informative and personalised approach to patient care. Yet many wearables are one dimensional, despite the underlying technology being common across a large array of tools. That is primarily due to the accompanying software, unmodifiable or black box-based scripts that generally lack accessibility or modification, meaning wearables may often get discarded. Use of wearables for sustainable healthcare needs careful consideration.

The Long-Term Sequelae of Traumatic Brain Injury Over 10 Years of Follow-Up—A Matched Cohort Study Based on Routine Data of a Statutory Health Insurance Carrier

BACKGROUND

The acute effects of traumatic brain injury (TBI) are well documented, but there is no systematic quantification of its long-term sequelae in Germanlanguage literature. The purpose of this article is to compare the frequency of conditions linked to prior TBI with their frequency in the non-brain-injured population.

METHODS

A matched cohort study was carried out on the basis of routine data from the BARMER statutory health insurance carrier. The exposure group consisted of patients treated over the period 2006-2009 for TBI at a variety of treatment intensities, including persons with multiple organ trauma. The control group consisted of BARMER insurees without prior TBI who were matched with the patients in the exposure group for age, sex, and pre-existing diseases. Late sequelae were sought in the routine data for a period of ten years after the injury. The outcome rates of the exposure and control groups were compared with Kaplan-Meier estimators and Poisson regression.

RESULTS

114 296 persons with TBI in the period 2006-2009 were included in the study. The mortality within ten years of TBI was 305 per 1000 individuals. The relative mortality in the exposure group was higher than that in control individuals of the same age and sex, with an incidence rate ratio (IRR) of 1.67 (95% confidence interval, [1.60; 1.74]). Immobility, dementia, epilepsy, endocrine disorders, functional disorders, depression, anxiety, cognitive deficits, headache, and sleep disorders were also more common in the exposure group. Persons with TBI requiring highintensity treatment displayed the highest relative incidence rates of the conditions studied over 10 years of follow-up. Persons who had been admitted to the hospital because of TBI had higher relative incidence rates for epilepsy and dementia than those who had been cared for on an outpatient basis.

CONCLUSION

Adverse sequelae of TBI can still be seen ten years after the exposure. These patients die earlier than persons without TBI and suffer earlier and more frequently from associated conditions.

Epidemiological and clinical characteristics predictive of ICU mortality of patients with traumatic brain injury treated at a trauma referral hospital - a cohort study

BACKGROUND

Traumatic brain injury (TBI) has substantial physical, psychological, social and economic impacts, with high rates of morbidity and mortality. Considering its high incidence, the aim of this study was to identify epidemiological and clinical characteristics that predict mortality in patients hospitalized for TBI in intensive care units (ICUs).

METHODS

A retrospective cohort study was carried out with patients over 18 years old with TBI admitted to an ICU of a Brazilian trauma referral hospital between January 2012 and August 2019. TBI was compared with other traumas in terms of clinical characteristics of ICU admission and outcome. Univariate and multivariate analyses were used to estimate the odds ratio for mortality.

RESULTS

Of the 4816 patients included, 1114 had TBI, with a predominance of males (85.1%). Compared with patients with other traumas, patients with TBI had a lower mean age (45.3 ± 19.1 versus 57.1 ± 24.1 years, p < 0.001), higher median APACHE II (19 versus 15, p < 0.001) and SOFA (6 versus 3, p < 0.001) scores, lower median Glasgow Coma Scale (GCS) score (10 versus 15, p < 0.001), higher median length of stay (7 days versus 4 days, p < 0.001) and higher mortality (27.6% versus 13.3%, p < 0.001). In the multivariate analysis, the predictors of mortality were older age (OR: 1.008 [1.002-1.015], p = 0.016), higher APACHE II score (OR: 1.180 [1.155-1.204], p < 0.001), lower GCS score for the first 24 h (OR: 0.730 [0.700-0.760], p < 0.001), greater number of brain injuries and presence of associated chest trauma (OR: 1.727 [1.192-2.501], p < 0.001).

CONCLUSION

Patients admitted to the ICU for TBI were younger and had worse prognostic scores, longer hospital stays and higher mortality than those admitted to the ICU for other traumas. The independent predictors of mortality were older age, high APACHE II score, low GCS score, number of brain injuries and association with chest trauma.

Does pre-injury clopidogrel use increase the risk of intracranial haemorrhage post head injury in adult patients? A systematic review and meta-analysis

BACKGROUND

Several current guidelines do not include antiplatelet use as an explicit indication for CT scan of the head following head injury. The impact of individual antiplatelet agent use on rates of intracranial haemorrhage is unclear. The primary objective of this systematic review was to assess if clopidogrel monotherapy was associated with traumatic intracranial haemorrhage (tICH) on CT of the head within 24 hours of presentation following head trauma compared with no antithrombotic controls.

METHODS

Eligible studies were non-randomised studies with participants aged ≥18 years old with head injury. Studies had to have conducted CT of the head within 24 hours of presentation and contain a no antithrombotic control group and a clopidogrel monotherapy group.Eight databases were searched from inception to December 2020. Assessment of identified studies against inclusion criteria and data extraction were carried out independently and in duplicate by two authors.Quality assessment and risk of bias (ROB) were assessed using the Newcastle-Ottawa Quality Assessment tool and Risk Of Bias In Non-randomised Studies of Interventions (ROBINS-I) tool. Meta-analysis was conducted using a random-effects model and reported as an OR and 95% CI.

RESULTS

Seven studies were eligible for inclusion with a total of 21 898 participants that were incorporated into the meta-analysis. Five studies were retrospective. Clopidogrel monotherapy was not significantly associated with an increase in risk of tICH compared with no antithrombotic controls (OR 0.97, 95% CI 0.54 to 1.75). Heterogeneity was high with an I² of 75%. Sensitivity analysis produced an I² of 21% and did not show a significant association between clopidogrel monotherapy and risk of tICH (OR 1.16, 95% CI 0.87 to 1.55). All studies scored for moderate to serious ROB on categories in the ROBINS-I tool.

CONCLUSION

Included studies were vulnerable to confounding and several were small-scale studies. The results should be interpreted with caution given the ROB identified. This study does not provide statistically significant evidence that clopidogrel monotherapy patients are at increased risk of tICH after head injury compared with no antithrombotic controls.

PROSPERO REGISTRATION NUMBER

CRD42020223541.

Lifetime Traumatic Brain Injury and Cognitive Domain Deficits in Late Life: The PROTECT-TBI Cohort Study

Traumatic brain injury (TBI) causes cognitive impairment but it remains contested regarding which cognitive domains are most affected. Further, moderate-severe TBI is known to be deleterious, but studies of mild TBI (mTBI) show a greater mix of negative and positive findings. This study examines the longer-term cognitive effects of TBI severity and number of mTBIs in later life. We examined a subset (n = 15,764) of the PROTECT study, a cohort assessing risk factors for cognitive decline (ages between 50 and 90 years). Participants completed cognitive assessments annually for 4 years. Cognitive tests were grouped using a principal components analysis (PCA) into working memory, episodic memory, attention, processing speed, and executive function. Lifetime TBI severity and number were retrospectively recalled by participants using the Brain Injury Screening Questionnaire (BISQ). Linear mixed models (LMMs) examined the effect of severity of head injury (non-TBI head strike, mTBI, and moderate-severe TBI) and number of mTBI at baseline and over time. mTBI was considered as a continuous and categorical variable (groups: 0 mTBI, 1 mTBI, 2 mTBIs, 3 mTBIs, and 4+ mTBIs). Of the participants 5725 (36.3%) reported at least one mTBI and 510 (3.2%) at least one moderate-severe TBI, whereas 3711 (23.5%) had suffered at worst a non-TBI head strike and 5818 (32.9%) reported no head injuries. The participants had suffered their last reported head injury an average (standard deviation, SD) of 29.6 (20.0) years prior to the study. Regarding outcomes, there was no worsening in longitudinal cognitive trajectories over the study duration but at baseline there were significant cognitive deficits associated with TBI. At baseline, compared with those without head injury, individuals reporting at least one moderate-severe TBI had significantly poorer attention (B = -0.163, p < 0.001), executive scores (B = -0.151, p = 0.004), and processing speed (B = -0.075, p = 0.033). Those who had suffered at least a single mTBI also demonstrated significantly poorer attention scores at baseline compared with the no head injury group (B = -0.052, p = 0.001). Compared with those with no mTBI, those in the 3 mTBI group manifested poorer baseline executive function (B = -0.149, p = 0.025) and attention scores (B = -0.085, p = 0.015). At baseline, those who had suffered four or more mTBIs demonstrated poorer attention (B = -0.135, p < 0.001), processing speed (B = -0.072, p = 0.009), and working memory (B = -0.052, p = 0.036), compared with those reporting no mTBI. TBI is associated with fixed, dose, and severity-dependent cognitive deficits. The most sensitive cognitive domains are attention and executive function, with approximately double the effect compared with processing speed and working memory. Post-TBI cognitive rehabilitation should be targeted appropriately to domain-specific effects. Significant long-term cognitive deficits were associated with three or more lifetime mTBIs, a critical consideration when counseling individuals post-TBI about continuing high-risk activities.

Post-concussion symptoms 1-year after traumatic brain injury: using the Rivermead Post-concussion Questionnaire to identify predictors of severity

BACKGROUND

Patients who suffer traumatic brain injury (TBI) often experience a constellation of physical, cognitive, and emotional/behavioral symptoms called "post-concussion symptoms" and subsequent long-term disability. This study aimed to investigate the incidence of persistent post-concussion symptoms and possible predictors of long-term disability focusing on demographic, injury, and psychological factors. It was hoped to identify groups at high risk.

METHODS

A prospective cohort of 1322 individuals admitted with TBI were assessed in a specialist neurorehabilitation clinic at 10 weeks and 1-year post injury between August 2011 and July 2015. The outcome (post-concussion symptoms) was measured using the Rivermead Post-concussion Questionnaire (RPQ) at 1-year post injury.

RESULTS

At 1 yr, 1131 individuals were identified (>90% follow-up). Over 20% exhibited moderate or severe symptom levels on RPQ. A linear regression model showed that previous psychiatric history, lower Glasgow Coma Scale (GCS), severe CT abnormalities, injury caused by assault, pre-injury unemployment, and inability to return to work at 6 weeks post-injury were associated with worse symptoms at 1 yr. The adjusted R² of the model was 25.1%.

CONCLUSION

These findings confirm the high incidence of post-concussion symptoms at 1 yr and identify certain associated features that increase risk. This may allow targeting of certain groups, e.g., return to work or victims of assault.

Utilization and Outcomes of Extracorporeal Membrane Oxygenation Following Traumatic Brain Injury in the United States

Objectives: Describe contemporary ECMO utilization patterns among patients with traumatic brain injury (TBI) and examine clinical outcomes among TBI patients requiring ECMO. Design: Retrospective cohort study. Setting: Premier Healthcare Database (PHD) between January 2016 to June 2020. Subjects: Adult patients with TBI who were mechanically ventilated and stratified by exposure to ECMO. Results: Among patients exposed to ECMO, we examined the following clinical outcomes: hospital LOS, ICU LOS, duration of mechanical ventilation, and hospital mortality. Of our initial cohort (n = 59,612), 118 patients (0.2%) were placed on ECMO during hospitalization. Most patients were placed on ECMO within the first 2 days of admission (54.3%). Factors associated with ECMO utilization included younger age (OR 0.96, 95% CI (0.95–0.97)), higher injury severity score (ISS) (OR 1.03, 95% CI (1.01–1.04)), vasopressor utilization (2.92, 95% CI (1.90–4.48)), tranexamic acid utilization (OR 1.84, 95% CI (1.12–3.04)), baseline comorbidities (OR 1.06, 95% CI (1.03–1.09)), and care in a teaching hospital (OR 3.04, 95% CI 1.31–7.05). A moderate degree (ICC = 19.5%) of variation in ECMO use was explained at the individual hospital level. Patients exposed to ECMO had longer median (IQR) hospital and ICU length of stay (LOS) [26 days (11–36) versus 9 days (4–8) and 19.5 days (8–32) versus 5 days (2–11), respectively] and a longer median (IQR) duration of mechanical ventilation [18 days (8–31) versus 3 days (2–8)]. Patients exposed to ECMO experienced a hospital mortality rate of 33.9%, compared to 21.2% of TBI patients unexposed to ECMO. Conclusions: ECMO utilization in mechanically ventilated patients with TBI is rare, with significant variation across hospitals. The impact of ECMO on healthcare utilization and hospital mortality following TBI is comparable to non-TBI conditions requiring ECMO. Further research is necessary to better understand the role of ECMO following TBI and identify patients who may benefit from this therapy.

Mortality as an indicator of quality of neurosurgical care in England: a retrospective cohort study

OBJECTIVES

Postoperative mortality is a widely used quality indicator, but it may be unreliable when procedure numbers and/or mortality rates are low, due to insufficient statistical power. The objective was to investigate the statistical validity of postoperative 30-day mortality as a quality metric for neurosurgical practice across healthcare providers.

DESIGN

Retrospective cohort study.

SETTING

Hospital Episode Statistics data from all neurosurgical units in England.

PARTICIPANTS

Patients who underwent neurosurgical procedures between April 2013 and March 2018. Procedures were grouped using the National Neurosurgical Audit Programme classification.

OUTCOMES MEASURED

National 30-day postoperative mortality rates were calculated for elective and non-elective neurosurgical procedural groups. The study estimated the proportion of neurosurgeons and NHS trusts in England that performed sufficient procedures in 3-year and 5-year periods to detect unusual performance (defined as double the national rate of mortality). The actual difference in mortality rates that could be reliably detected based on procedure volumes of neurosurgeons and units over a 5-year period was modelled.

RESULTS

The 30-day mortality rates for all elective and non-elective procedures were 0.4% and 6.1%, respectively. Only one neurosurgeon in England achieved the minimum sample size (n=2402) of elective cases in 5 years needed to detect if their mortality rate was double the national average. All neurosurgical units achieved the minimum sample sizes for both elective (n=2402) and non-elective (n=149) procedures. In several neurosurgical subspecialties, approximately 80% of units (or more) achieved the minimum sample sizes needed to detect if their mortality rate was double the national rate, including elective neuro-oncology (baseline mortality rate=2.3%), non-elective neuro-oncology (rate=5.7%), neurovascular (rate=6.7%) and trauma (rate=11%).

CONCLUSION

Postoperative mortality lacks statistical power as a measure of individual neurosurgeon performance. Neurosurgical units in England performed sufficient procedure numbers overall and in several subspecialty areas to support the use of mortality as a quality indicator.

Enhanced neurotrauma services: physician input into traumatic brain injury care

Elderly trauma victims whose care is shared between surgeons and physicians have improved clinical outcomes and shorter hospital lengths of stay (LOS). To test whether a similar benefit can be gained for patients suffering traumatic brain injury (TBI), a quality improvement project (QIP) was run in which a neurologist was enrolled into the pre-existing neurotrauma team. Mortality rates, LOS and rates of readmission within 30 days of discharge were compared between two cohorts of TBI patients: 80 admittedly prior to the QIP and 80 admitted during the QIP. The two cohorts were well matched for age, gender, mechanism of injury, Glasgow coma score and types of injury. The QIP was not associated with a reduction in mortality but was associated with a significant reduction in mean LOS (from 25.7 days to 17.5 days; p=0.04) and a reduction in readmissions (from seven to zero patients; p=0.01).

Concussion in the UK: a contemporary narrative review

Concussion has been receiving an increasing amount of media exposure following several high-profile professional sports controversies and multimillion-dollar lawsuits. The potential life-changing sequalae of concussion and the rare, but devasting, second impact syndrome have also gained much attention. Despite this, our knowledge of the pathological processes involved is limited and often extrapolated from research into more severe brain injuries. As there is no objective diagnostic test for concussion. Relying on history and examination only, the diagnosis of concussion has become the rate-limiting step in widening research into the disease. Clinical study protocols therefore frequently exclude the most vulnerable groups of patients such as those with existing cognitive impairment, concurrent intoxication, mental health issues or learning difficulties. This up-to-date narrative review aims to summarize our current concussion knowledge and provides an insight into promising avenues for future research.

Prediction of early prognosis after traumatic brain injury by multifactor model

AIMS

To design a model to predict the early prognosis of patients with traumatic brain injury (TBI) based on parameters that can be quickly obtained in emergency conditions from medical history, physical examination, and supplementary examinations.

METHODS

The medical records of TBI patients who were hospitalized in two medical institutions between June 2015 and June 2021 were collected and analyzed. Patients were divided into the training set, validation set, and testing set. The possible predictive indicators were screened after analyzing the data of patients in the training set. Then prediction models were found based on the possible predictive indicators in the training set. Data of patients in the validation set and the testing set was provided to validate the predictive values of the models.

RESULTS

Age, Glasgow coma scale score, Apolipoprotein E genotype, damage area, serum C-reactive protein, and interleukin-8 (IL-8) levels, and Marshall computed tomography score were found associated with early prognosis of TBI patients. The accuracy of the early prognosis prediction model (EPPM) was 80%, and the sensitivity and specificity of the EPPM were 78.8% and 80.8% in the training set. The accuracy of the EPPM was 79%, and the sensitivity and specificity of the EPPM were 66.7% and 86.2% in the validation set. The accuracy of the early EPPM was 69.1%, and the sensitivity and specificity of the EPPM were 67.9% and 77.8% in the testing set.

CONCLUSION

Prediction models integrating general information, clinical manifestations, and auxiliary examination results may provide a reliable and rapid method to evaluate and predict the early prognosis of TBI patients.

What are the demographic and clinical differences between those older adults with traumatic brain injury who receive a neurosurgical intervention to those that do not? A systematic literature review with narrative synthesis

OBJECTIVES

This review aimed to identify the demographic and clinical differences between those older adults admitted directly under neurosurgical care and those that were not, and whether EMS clinicians could use these differences to improve patient triage.

METHODS

The authors searched for papers that included older adults who had suffered a TBI and were either admitted directly under neurosurgical care or were not. Titles and abstracts were screened, shortlisting potentially eligible papers before performing a full-text review. The Newcastle-Ottawa Scale was used to assess the risk of bias.

RESULTS

A total of nine studies were eligible for inclusion. A high abbreviated injury score head, Marshall score or subdural hematoma greater than 10 mm were associated with neurosurgical care. There were few differences between those patients who did and did not receive neurosurgical intervention.

CONCLUSIONS

Absence of guidelines and clinician bias means that differences between those treated aggressively and conservatively observed in the literature are fraught with bias. Further work is required to understand which patients would benefit from an escalation of care and whether EMS can identify these patients so they are transported directly to a hospital with the appropriate services on-site.

The diagnostic accuracy of prehospital triage tools in identifying patients with traumatic brain injury: A systematic review

INTRODUCTION

Prehospital care providers are usually the first responders for patients with traumatic brain injury (TBI). Early identification of patients with TBI enables them to receive trauma centre care, which improves outcomes. Two recent systematic reviews concluded that prehospital triage tools for undifferentiated major trauma have low accuracy. However, neither review focused specifically on patients with suspected TBI. Therefore, we aimed to systematically review the existing evidence on the diagnostic performance of prehospital triage tools for patients with suspected TBI.

METHODS

A comprehensive search of the current literature was conducted using Medline, EMBASE, CINAHL Plus and the Cochrane library (inception to 1st June 2021). We also searched Google Scholar, OpenGrey, pre-prints (MedRxiv) and dissertation databases. We included all studies published in English language evaluating the accuracy of prehospital triage tools for TBI. We assessed methodological quality and risk of bias using a modified Quality Assessment of Diagnostic Studies (QUADAS-2) tool. Two reviewers independently performed searches, screened titles and abstracts and undertook methodological quality assessments. Due to the heterogeneity in the population of interest and prehospital triage tools used, a narrative synthesis was undertaken.

RESULTS

The initial search identified 1787 articles, of which 8 unique eligible studies met the inclusion criteria (5 retrospective, 2 prospective, 1 mixed). Overall, sensitivity of triage tools studied ranged from 19.8% to 87.9% for TBI identification. Specificity ranged from 41.4% to 94.4%. Two decision tools have been validated more than once: HITS-NS (2 studies, sensitivity 28.3-32.6%, specificity 89.1-94.4%) and the Field Triage Decision Scheme (4 studies, sensitivity 19.8-64.5%, specificity 77.4%-93.1%). Existing tools appear to systematically under-triage older patients.

CONCLUSION

Further efforts are needed to improve and optimise prehospital triage tools. Consideration of additional predictors (e.g., biomarkers, clinical decision aids and paramedic judgement) may be required to improve diagnostic accuracy.

A cost-effectiveness and value of information analysis to inform future research of tranexamic acid for older adults experiencing mild traumatic brain injury

BACKGROUND

Tranexamic acid reduces head injury deaths in patients with CT scan evidence of intracranial bleeding after mild traumatic brain injury (TBI). However, the cost-effectiveness of tranexamic acid for people with mild TBI in the pre-hospital setting, prior to CT scanning, is uncertain. A large randomised controlled trial (CRASH-4) is planned to address this issue, but the economic justification for it has not been established. The aim of the analysis was to estimate the likelihood of tranexamic acid being cost-effective given current evidence, the treatment effects required for cost-effectiveness, and the expected value of performing further research.

METHODS

An early economic decision model compared usual care for mild TBI with and without tranexamic acid, for adults aged 70 and above. The evaluation was performed from a UK healthcare perspective over a lifetime time horizon, with costs reported in 2020 pounds (GBP) and outcomes reported as quality-adjusted life years (QALYs). All analyses used a £20,000 per QALY cost-effectiveness threshold.

RESULTS

In the base case analysis, tranexamic acid was associated with an incremental cost-effectiveness ratio of £4885 per QALY gained, but the likelihood of it being cost-effective was highly dependent on the all-cause mortality treatment effect. The value of perfect information was £22.4 million, and the value of perfect information for parameters that could be collected in a trial was £21.9 million. The all-cause mortality risk ratio for tranexamic acid and the functional outcomes following TBI had the most impact on cost-effectiveness.

CONCLUSIONS

There is a high degree of uncertainty in the cost-effectiveness of tranexamic acid for older adults experiencing mild TBI, meaning there is a high value of performing future research in the UK. The value in a global context is likely to be far higher.

Sugar or salt ("SOS"): A protocol for a UK multicentre randomised trial of mannitol and hypertonic saline in severe traumatic brain injury and intracranial hypertension

Hyperosmolar solutions are widely used to treat raised intracranial pressure following severe traumatic brain injury. Although mannitol has historically been the most frequently administered, hypertonic saline solutions are increasingly being used. However, definitive evidence regarding their comparative effectiveness is lacking. The Sugar or Salt Trial is a UK randomised, allocation concealed open label multicentre pragmatic trial designed to determine the clinical and cost-effectiveness of hypertonic saline compared with mannitol in the management of patients with severe traumatic brain injury. Patients requiring intensive care unit admission and intracranial pressure monitoring post-traumatic brain injury will be allocated at random to receive equi-osmolar boluses of either mannitol or hypertonic saline following failure of routine first-line measures to control intracranial pressure. The primary outcome for the study will be the Extended Glasgow Outcome Scale assessed at six months after randomisation. Results will inform current clinical practice in the routine use of hyperosmolar therapy as well as assess the impact of potential side effects. Pre-planned longer term clinical and cost effectiveness analyses will further inform the use of these treatments.

A scoping review on the challenges, improvement programs, and relevant output metrics for neurotrauma services in major trauma centers

Background:

For a neurotrauma unit to be defined as a structured neurotrauma service (NS) the following criteria must be satisfied: A dedicated neurointensive care unit, endovascular neuroradiology, in-hospital neurorehabilitation unit and helicopter platform within the context of a Level I trauma center. Designing an effective NS can be challenging, particularly when considering the different priorities and resources of countries across the globe. In addition the impact on clinical outcomes is not clearly established.

Methods:

A scoping review of the literature spanning from 2000 to 2020 meant to identify protocols, guidelines, and best practices for the management of traumatic brain injury (TBI) in NS was conducted on the US National Library of Medicine and National Institute of Health databases.

Results:

Limited evidence is available regarding quantitative and qualitative metrics to assess the impact of NSs and specialist follow-up clinics on patients’ outcome. Of note, the available literature used to lack detailed reports for: (a) Geographical clusters, such as low-to-middle income countries (LMIC); (b) clinical subgroups, such as mild TBI; and (c) long-term management, such as rehabilitation services. Only in the last few years more attention has been paid to those research topics.

Conclusion:

NSs can positively impact the management of the broad spectrum of TBI in different clinical settings; however more research on patients’ outcomes and quality of life metrics is needed to establish their efficacy. The collaboration of global clinicians and the development of international guidelines applicable also to LMIC are warranted.

Vibrational spectroscopy for the triage of traumatic brain injury CT priority and hospital admissions

Computed Tomogram (CT) brain imaging is routinely used to support clinical decision-making in patients with traumatic brain injury (TBI). However, only 7% of scans demonstrate evidence of TBI. The other 93% of scans contribute a significant cost to the healthcare system and a radiation risk to patients. There may be better strategies to identify which patients, particularly those with mild TBI, are at risk of deterioration and require hospital admission. We introduce a blood serum liquid biopsy that utilises attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) spectroscopy with machine learning algorithms as a decision-making tool to identify which mild TBI patients will most benefit from CT brain imaging. Serum samples were obtained from (n=298) patients who had acquired a TBI and were enrolled in CENTER-TBI, and from asymptomatic control patients (n=87). Injury patients (all severities) were stratified against non-injury controls. The mild TBI cohort was further examined by stratifying those who had at least one CT abnormality against those who had no CT abnormalities. The test performed exceptionally well in classifications of mild injury patients versus non-injury controls (sensitivity = 96.4% and specificity = 98.0%) and also provided a sensitivity of 80.2% when stratifying mild patients with at least one CT abnormality against those without. The results provided illustrate the test ability to identify 4 out of every 5 CT abnormalities and shows great promise to be introduced as a triage tool for CT priority in mild TBI patients.

Pattern and Outcome of Traumatic Brain Injury, Addis Ababa, Ethiopia: A Cross-sectional Hospital-based Study

BACKGROUND

Traumatic brain injury (TBI) is the leading cause of death and disability in young adults in the world. This study assessed clinical characteristics and in-hospital outcomes among traumatic brain injury patients presenting to Addis Ababa Burn, Emergency, and Trauma hospital.

METHODS

A cross-sectional hospital-based survey was conducted at AaBET hospital from January 01/2020 to April 30/2020. Data were collected using structured questionnaires from the trauma registry and patient chart. The collected data were analyzed using statistical software SPSS v 25.0.

RESULTS

Among the 304 traumatic brain injury patients, 75% were males with a mean age of 30.4 + 15.7, and 59.2% came from the Oromia region. Road traffic injury was responsible for 45% of the cases, of which pedestrian struck accounts for 52.2% of the cases. Only 50 (16.4%) patients arrived below 02 hours. 201 (66.1%) patients had mild traumatic brain injury the rest had moderate to severe traumatic brain injury. Skullbone fracture (linear, DSF, & BSF) was the most common (n=157, 63.1%) followed by intracerebral lesions (DAI, brain contusion, & ICH) (n=140, 56.5%). Forty-three (14.1%) patients were intubated. 45(14.8%) cases had a neurosurgical intervention. The mortality rate of severe, moderate, & mild TBI were 25%, 8.0% & 2.0% respectively with an overall mortality of 5.6%.

CONCLUSION

This study showed road traffic injury was the commonest cause of traumatic brain injury which affected young age groups. There was a delayed presentation to AaBET hospital Emergency. The mortality rate was lower than other Ethiopian hospital studies.

Patterns and outcomes of neurosurgery in England over a five-year period: A national retrospective cohort study

BACKGROUND

Neurosurgical practice has seen major changes over several decades. There are no recent evaluations of national neurosurgical practice. The aim of this observational study was to describe neurosurgical practice in England and to use outcomes to assess and benchmark the quality of care in neurosurgery.

MATERIAL AND METHODS

This national retrospective cohort study analysed Hospital Episode Statistics (HES) data from April 2013 to March 2018 for all adult admissions with a specialty code for neurosurgery. The epidemiology of patients and RCS Charlson comorbidities were derived and procedure incidence rates per 100,000 person-years calculated. Post-operative outcomes for elective and non-elective patients included: median length of stay, the proportion of patients requiring additional inpatient neurosurgical procedures, the proportion of patients discharged to their usual address, and in-hospital mortality rates.

RESULTS

During the 5-year study period, there were 371,418 admissions to neurosurgery. The proportion of admissions involving a neurosurgical procedure was 77.3% (n = 287,077). Of these, 45% were for cranial surgery and 37% for spinal. Overall, 68.3% were elective procedures. The incidence rates of most procedures were low (<20 per 100,000 person-years). Following elective neurosurgical procedures, in-hospital mortality rates for cranial and spinal surgery were 0.5% (95% CI, 0.5-0.6) and 0.1% (95% CI, 0.04-0.1), respectively. After non-elective neurosurgery, mortality rates were 7.4% (95% CI, 7.2-7.6) and 1.3% (95% CI, 1.2-1.5) for cranial and spinal surgery, respectively. Approximately 1 in 4 patients had additional procedures following non-elective cranial surgery (24%; 95% CI, 23.6-24.3). Outcomes were highly variable across different subspecialty areas.

CONCLUSIONS

The incidence rates of neurosurgical procedures are low within England, and neurosurgical units have a high volume of non-surgical admissions. In-hospital mortality rates after elective neurosurgery are low but there may be opportunities for quality improvement programmes to improve outcomes for non-elective surgery as well as ensuring equitable access to treatment.

Supplemental oxygen for traumatic brain injury: A systematic review

BACKGROUND

Oxygen supplementation is recommended after traumatic brain injury (TBI) but excessive oxygen may be harmful. The aim of this study was to investigate the effect of supplemental oxygen or high/low inspiratory oxygen fraction (FiO₂ ) for TBI patients on in-hospital mortality.

METHODS

We searched Medline (Pubmed), EMBASE and the Cochrane Library for interventional and observational studies fulfilling the following criteria: TBI patients >17 years (population); initial use of supplemental oxygen/high (≥0.6) FiO₂ (intervention) vs no supplemental oxygen/low (<0.6) FiO₂ (control) for spontaneously breathing or mechanically ventilated TBI patients, respectively with in-hospital mortality as primary outcome. Secondary outcomes were 30-day and 1-year mortality, length of stay in hospital or intensive care unit, days on mechanical ventilation, complications, and neurological impairment.

RESULTS

We screened 4846 citations. Two interventional studies comparing high vs low FiO₂ for mechanically ventilated TBI patients were included. No difference in in-hospital mortality was found. The first study found a statistically significant shorter length of stay in the intensive care unit for the high FiO₂ -group (6.5 [4.6-11.4] vs. 11.4 [5.8-17.2] days, p = 0.02). The second study found a lower disability at 6 months in the high FiO₂ -group with low disability in 25 (73.5%) vs. 15 (44.1%), moderate disability in 9 (26.5%) vs. 16 (47.1%), and severe disability in 0 (0.0%) vs. 3 (8.8%), p = 0.02.

CONCLUSION

Evidence on the effect of initial use of high/low FiO₂ for TBI patients on in-hospital mortality was extremely limited. Evidence on the use of supplemental oxygen for spontaneously breathing TBI patients is lacking.

The relationship between road traffic collision dynamics and traumatic brain injury pathology

Road traffic collisions are a major cause of traumatic brain injury. However, the relationship between road traffic collision dynamics and traumatic brain injury risk for different road users is unknown. We investigated 2065 collisions from Great Britain’s Road Accident In-depth Studies collision database involving 5374 subjects (2013–20). Five hundred and ninety-five subjects sustained a traumatic brain injury (20.2% of 2940 casualties), including 315 moderate–severe and 133 mild–probable injuries. Key pathologies included skull fracture (179, 31.9%), subarachnoid haemorrhage (171, 30.5%), focal brain injury (168, 29.9%) and subdural haematoma (96, 17.1%). These results were extended nationally using >1 000 000 police-reported collision casualties. Extrapolating from the in-depth data we estimate that there are ∼20 000 traumatic brain injury casualties (∼5000 moderate–severe) annually on Great Britain’s roads, accounting for severity differences. Detailed collision investigation allows vehicle collision dynamics to be understood and the change in velocity (known as delta-V) to be estimated for a subset of in-depth collision data. Higher delta-V increased the risk of moderate–severe brain injury for all road users. The four key pathologies were not observed below 8 km/h delta-V for pedestrians/cyclists and 19 km/h delta-V for car occupants (higher delta-V threshold for focal injury in both groups). Traumatic brain injury risk depended on road user type, delta-V and impact direction. Accounting for delta-V, pedestrians/cyclists had a 6-times higher likelihood of moderate–severe brain injury than car occupants. Wearing a cycle helmet during a collision was protective against overall and mild-to-moderate-to-severe brain injury, particularly skull fracture and subdural haematoma. Cycle helmet protection was not due to travel or impact speed differences between helmeted and non-helmeted cyclist groups. We additionally examined the influence of the delta-V direction. Car occupants exposed to a higher lateral delta-V component had a greater prevalence of moderate–severe brain injury, particularly subarachnoid haemorrhage. Multivariate logistic regression models created using total delta-V value and whether lateral delta-V was dominant had the best prediction capabilities (area under the receiver operator curve as high as 0.95). Collision notification systems are routinely fitted in new cars. These record delta-V and automatically alert emergency services to a collision in real-time. These risk relationships could, therefore, inform how routinely fitted automatic collision notification systems alert the emergency services to collisions with a high brain injury risk. Early notification of high-risk scenarios would enable quicker activation of the highest level of emergency service response. Identifying those that require neurosurgical care and ensuring they are transported directly to a centre with neuro-specialist provisions could improve patient outcomes.

Nationwide improvements in geriatric mortality due to traumatic brain injury in Japan

BACKGROUND

Traumatic brain injury (TBI), both isolated and in combination with extracranial lesions, is a global health problem associated with high mortality. Among various risk factors for poor clinical outcomes, age is the most important independent predictor of mortality in patients with TBI. TBI-related mortality is expected to increase as the society ages. However, in a super-aged society such as Japan, little is known about the trend of TBI-related mortality among older adults. Herein, we assessed the nationwide trend of the incidence and clinical outcomes of geriatric patients with TBI in Japan using the national Japanese Trauma Data Bank (JTDB) registry.

METHODS

In this retrospective cohort study, cases of TBI (aged ≥65 years) in hospitals registered with the JTDB database between January 2004 and December 2018 were included. In-hospital mortality was the primary outcome, and mortality in the emergency department was the secondary outcome. The odds ratios (ORs) and 95% confidence intervals (CIs) for in-hospital deaths with respect to 3-year periods were assessed using multivariable analysis after adjusting for potential confounders.

RESULTS

The main cause of TBI in older individuals was falls. The proportion of patients who died after hospitalization during the study period decreased markedly from 29.5% (194/657) during 2004-2006 to 14.2% (1309/9240) during 2016-2018 in the isolated TBI group (adjusted OR = 0.42, 95% CI: 0.33-0.53) and from 48.0% (119/248) during 2004-2006 to 21.7% (689/3172) during 2016-2018 in the multiple trauma group (adjusted OR = 0.32, 95% CI: 0.23-0.45). The adjusted ORs for the 3-year increment were 0.84 (95% CI: 0.81-0.88) and 0.78 (95% CI: 0.75-0.83) for the isolated TBI and multiple trauma groups, respectively.

CONCLUSIONS

Using the national JTDB registry, we demonstrated a nationwide reduction in TBI-related mortality. Our findings in the super-aged society of Japan may provide insight for the treatment of geriatric patients with TBI worldwide.

Imaging of Skull Base Trauma: Fracture Patterns and Soft Tissue Injuries

This article provides an overview of the patterns of skull base trauma and provides a review of the pertinent soft tissue injuries and complications that can ensue. A brief review of skull base anatomy is provided with subsequent focus on the important findings in anterior, central, and posterior skull base trauma.

Brain-lung interactions and mechanical ventilation in patients with isolated brain injury

During the last decade, experimental and clinical studies have demonstrated that isolated acute brain injury (ABI) may cause severe dysfunction of peripheral extracranial organs and systems. Of all potential target organs and systems, the lung appears to be the most vulnerable to damage after brain injury (BI). The pathophysiology of these brain–lung interactions are complex and involve neurogenic pulmonary oedema, inflammation, neurodegeneration, neurotransmitters, immune suppression and dysfunction of the autonomic system. The systemic effects of inflammatory mediators in patients with BI create a systemic inflammatory environment that makes extracranial organs vulnerable to secondary procedures that enhance inflammation, such as mechanical ventilation (MV), surgery and infections. Indeed, previous studies have shown that in the presence of a systemic inflammatory environment, specific neurointensive care interventions—such as MV—may significantly contribute to the development of lung injury, regardless of the underlying mechanisms. Although current knowledge supports protective ventilation in patients with BI, it must be born in mind that ABI-related lung injury has distinct mechanisms that involve complex interactions between the brain and lungs. In this context, the role of extracerebral pathophysiology, especially in the lungs, has often been overlooked, as most physicians focus on intracranial injury and cerebral dysfunction. The present review aims to fill this gap by describing the pathophysiology of complications due to lung injuries in patients with a single ABI, and discusses the possible impact of MV in neurocritical care patients with normal lungs.

Deterioration After Mild Traumatic Brain Injury: A Single-Center Experience With Cost Analysis

Background: Most traumatic brain injuries (TBIs) are mild (GCS score of 13–15). Patients with mild TBI (mTBI) are generally in good condition. In some cases, a neurological deterioration (manifested by a drop of ≥1 point in GCS score) can occur and neurosurgical intervention (NI) may be needed. Because of that, these patients are frequently admitted to a hospital for observation. The aim of our study was to determine the number of patients with mTBI that deteriorate or need NI. We also considered an economic aspect of hospital admissions of these patients.

Methods: The study group consisted of 186 adult patients admitted to the neurosurgical department due to mTBI. Patients were divided into three groups according to an initial GCS score. The occurrence of deterioration, need for NI, length of stay (LOS), cost of stay and occurrence of death were analyzed.

Results: The deterioration was observed in 7 (3.76%) out of all cases. In 3 (1.61%) of them, the NI was needed. The average LOS was 7.96 days and it was closely linked with an initial GCS score (p < 0.001). The total cost of stay of all patients included in this study was about 1,188,668 PLN (306,357 USD).

Conclusion: The deterioration occurred in a small number of patients with mTBI, the need for NI was even less common. Hospitalization of these patients is expensive. Further studies with prognostic model helping decide on admission/discharge are necessary.

Does amantadine maintain function in long-established brain injury? A single case experimental design

OBJECTIVE

The role of dopamine agonist (DA) in restoring consciousness and cognition in recovery phase following acquired brain injury (ABI) is established ^(1-5). The role in later recovery is less well defined. We report a single case experimental design (SCED) trial of amantadine demonstrating improvement in function, six years following ABI.

METHOD

A scoring system based on established abilities in personal care and interaction was used to identify tasks with component actions, 34 actions in total, each ranked in terms of quality of response to a request or prompt. Actions were scored on maintenance dose amantadine; on withdrawal; and after reintroduction. Daytime sleep duration was also recorded.

RESULTS

At 3^rd and 5^th weeks post withdrawal, deterioration was noted in 27 of 34 graded activities. At 3^rd and 5^th weeks following reintroduction, all but 3 grades returned to baseline or better. Afternoon sleep duration increased from 35 to 80 minutes during withdrawal period returning towards baseline on amantadine resumption.

CONCLUSION

We believe this provides evidence for benefit of amantadine in sustaining function following ABI. The SCED model used provides a template for others to use to identify comparable change in similar trials.

Changes in Mortality Related to Traumatic Brain Injuries in the Seychelles from 1989 to 2018

Introduction: Traumatic Brain Injuries (TBIs) are a significant source of disability and mortality, which disproportionately affect low- and middle-income countries. The Republic of Seychelles is a country in the African region that has experienced rapid socio-economic development and one in which all deaths and the age distribution of the population have been enumerated for the past few decades. The aim of this study was to investigate TBI-related mortality changes in the Republic of Seychelles during 1989–2018.

Methods: All TBI-related deaths were ascertained using the national Civil Registration and Vital Statistics System. Age- and sex-standardised mortality rates (per 100,000 person-years) were standardised to the age distribution of the World Health Organisation standard population.

Results: The 30-year age-standardised TBI-related mortality rates were 22.6 (95% CI 19.9, 25.2) in males and 4.0 (95% CI 2.9, 5.1) in females. Road traffic collisions were the leading contributor to TBI-related mortality [10.0 (95% CI 8.2, 11.8) in males and 2.7 (95% CI 1.8, 3.6) in females, P > 0.05]. TBI-related mortality was most frequent at age 20–39 years in males (8.0) and at age 0–19 in females (1.4). Comparing 2004–2018 vs. 1989–2003, the age-standardised mortality rates changed in males/females by −20%/−11% (all cause mortality), −24%/+39.4% (TBIs) and +1%/+34.8% (road traffic injury-related TBI).

Conclusion: TBI-related mortality rates were much higher in males but decreased over time. Road traffic collisions were the single greatest contributor to TBI mortality, emphasising the importance of road safety measures.

The Burden of Traumatic Brain Injury in Sub-Saharan Africa: A Scoping Review

BACKGROUND

Despite the growing incidence of traumatic brain injury (TBI) in Sub-Saharan Africa, there is yet to be a study to map the current burden of the disease on the continent. This scoping review aims to outline the literature on TBI.

METHODS

This scoping review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for scoping reviews. A search string was developed to identify studies relating to TBI epidemiology, management, and outcomes. The search was applied to Medline, Embase, and Global Medicus Index.

RESULTS

In total, 107 studies were included in the final analysis. More than one half originated from South Africa. Seventy-five studies were published in 2013 or later. Studies recruited a median of 115 patients: 83.5 male and 31 female. TBI affected all age groups (range = 0-105 years) and sexes but was more common among young males aged 20-40. Road traffic accidents caused TBI in a median of 71 patients. Other major causes included assault (median = 39.5) and falls (median = 12.5). Craniectomies were the most commonly reported surgical treatment (18.7%) followed by burr holes (7.5%). Four studies (3.7%) reported delays in seeking neurotrauma care, with delays in reaching a neurotrauma facility and delays in receiving care being reported in 15 studies (14%) each. Glasgow Outcome Scale score was reported in 28 (26.1%) studies, whereas quality of life measures were reported in 2 (1%). Younger age was associated with favorable outcomes.

CONCLUSIONS

There is an increased need for TBI research, education, and training in Sub-Saharan Africa. This will aid stakeholders in optimizing patient management and outcome.

Cerebral Microdialysate Metabolite Monitoring using Mid-infrared Spectroscopy

The brains of patients suffering from traumatic brain-injury (TBI) undergo dynamic chemical changes in the days following the initial trauma. Accurate and timely monitoring of these changes is of paramount importance for improved patient outcome. Conventional brain-chemistry monitoring is performed off-line by collecting and manually transferring microdialysis samples to an enzymatic colorimetric bedside analyzer every hour, which detects and quantifies the molecules of interest. However, off-line, hourly monitoring means that any subhourly neurochemical changes, which may be detrimental to patients, go unseen and thus untreated. Mid-infrared (mid-IR) spectroscopy allows rapid, reagent-free, molecular fingerprinting of liquid samples, and can be easily integrated with microfluidics. We used mid-IR transmission spectroscopy to analyze glucose, lactate, and pyruvate, three relevant brain metabolites, in the extracellular brain fluid of two TBI patients, sampled via microdialysis. Detection limits of 0.5, 0.2, and 0.1 mM were achieved for pure glucose, lactate, and pyruvate, respectively, in perfusion fluid using an external cavity-quantum cascade laser (EC-QCL) system with an integrated transmission flow-cell. Microdialysates were collected hourly, then pooled (3-4 h), and measured consecutively using the standard ISCUSflex analyzer and the EC-QCL system. There was a strong correlation between the compound concentrations obtained using the conventional bedside analyzer and the acquired mid-IR absorbance spectra, where a partial-least-squares regression model was implemented to compute concentrations. This study demonstrates the potential utility of mid-IR spectroscopy for continuous, automated, reagent-free, and online monitoring of the dynamic chemical changes in TBI patients, allowing a more timely response to adverse brain metabolism and consequently improving patient outcomes.

The burden of traumatic brain injury from low-energy falls among patients from 18 countries in the CENTER-TBI Registry: A comparative cohort study

BACKGROUND

Traumatic brain injury (TBI) is an important global public health burden, where those injured by high-energy transfer (e.g., road traffic collisions) are assumed to have more severe injury and are prioritised by emergency medical service trauma triage tools. However recent studies suggest an increasing TBI disease burden in older people injured through low-energy falls. We aimed to assess the prevalence of low-energy falls among patients presenting to hospital with TBI, and to compare their characteristics, care pathways, and outcomes to TBI caused by high-energy trauma.

METHODS AND FINDINGS

We conducted a comparative cohort study utilising the CENTER-TBI (Collaborative European NeuroTrauma Effectiveness Research in TBI) Registry, which recorded patient demographics, injury, care pathway, and acute care outcome data in 56 acute trauma receiving hospitals across 18 countries (17 countries in Europe and Israel). Patients presenting with TBI and indications for computed tomography (CT) brain scan between 2014 to 2018 were purposively sampled. The main study outcomes were (i) the prevalence of low-energy falls causing TBI within the overall cohort and (ii) comparisons of TBI patients injured by low-energy falls to TBI patients injured by high-energy transfer-in terms of demographic and injury characteristics, care pathways, and hospital mortality. In total, 22,782 eligible patients were enrolled, and study outcomes were analysed for 21,681 TBI patients with known injury mechanism; 40% (95% CI 39% to 41%) (8,622/21,681) of patients with TBI were injured by low-energy falls. Compared to 13,059 patients injured by high-energy transfer (HE cohort), the those injured through low-energy falls (LE cohort) were older (LE cohort, median 74 [IQR 56 to 84] years, versus HE cohort, median 42 [IQR 25 to 60] years; p < 0.001), more often female (LE cohort, 50% [95% CI 48% to 51%], versus HE cohort, 32% [95% CI 31% to 34%]; p < 0.001), more frequently taking pre-injury anticoagulants or/and platelet aggregation inhibitors (LE cohort, 44% [95% CI 42% to 45%], versus HE cohort, 13% [95% CI 11% to 14%]; p < 0.001), and less often presenting with moderately or severely impaired conscious level (LE cohort, 7.8% [95% CI 5.6% to 9.8%], versus HE cohort, 10% [95% CI 8.7% to 12%]; p < 0.001), but had similar in-hospital mortality (LE cohort, 6.3% [95% CI 4.2% to 8.3%], versus HE cohort, 7.0% [95% CI 5.3% to 8.6%]; p = 0.83). The CT brain scan traumatic abnormality rate was 3% lower in the LE cohort (LE cohort, 29% [95% CI 27% to 31%], versus HE cohort, 32% [95% CI 31% to 34%]; p < 0.001); individuals in the LE cohort were 50% less likely to receive critical care (LE cohort, 12% [95% CI 9.5% to 13%], versus HE cohort, 24% [95% CI 23% to 26%]; p < 0.001) or emergency interventions (LE cohort, 7.5% [95% CI 5.4% to 9.5%], versus HE cohort, 13% [95% CI 12% to 15%]; p < 0.001) than patients injured by high-energy transfer. The purposive sampling strategy and censorship of patient outcomes beyond hospital discharge are the main study limitations.

CONCLUSIONS

We observed that patients sustaining TBI from low-energy falls are an important component of the TBI disease burden and a distinct demographic cohort; further, our findings suggest that energy transfer may not predict intracranial injury or acute care mortality in patients with TBI presenting to hospital. This suggests that factors beyond energy transfer level may be more relevant to prehospital and emergency department TBI triage in older people. A specific focus to improve prevention and care for patients sustaining TBI from low-energy falls is required.

Prospective observational cohort study on epidemiology, treatment and outcome of patients with traumatic brain injury (TBI) in German BG hospitals

OBJECTIVES

Since 2000/2001, no large-scale prospective studies addressing traumatic brain injury (TBI) epidemiology in Germany have been published. Our aim was to look for a possible shift in TBI epidemiology described in other European countries, to look for possible changes in TBI management and to identify predictors of 1-year outcome especially in patients with mild TBI.

DESIGN

Observational cohort study.

SETTING

All patients suffering from a TBI of any degree between 1 October 2014 and 30 September 2015, and who arrived in one of the seven participating BG hospitals within 24 hours after trauma, were included.

PARTICIPANTS

In total, 3514 patients were included.

OUTCOME MEASURES

Initial care, acute hospital care and rehabilitation were documented using standardised documentation forms. A standardised telephone interview was conducted 3 and 12 months after TBI in order to obtain information on outcome.

RESULTS

Peaks were identified in males in the early 20s and mid-50s, and in both sexes in the late 70s, with 25% of all patients aged 75 or older. A fall was the most frequent cause of TBI, followed by traffic accidents (especially bicyclists). The number of head CT scans increased, and the number of conventional X-rays of the skull decreased compared with 2000/2001. Besides, more patients were offered rehabilitation than before. Though most TBI were classified as mild, one-third of the patients participating in the telephone interview after 12 months still reported troubles attributed to TBI. Negative predictors in mild TBI were female gender, intracranial bleeding and Glasgow Coma Scale (GCS) 13/14.

CONCLUSION

The observed epidemiologic shift in TBI (ie, elderly patients, more falls, more bicyclists) calls for targeted preventive measures. The heterogeneity behind the diagnosis 'mild TBI' emphasises the need for defining subgroups not only based on GCS.

Platelet Receptor Activity for Predicting Survival in Patients with Intracranial Bleeding

Blood coagulation disorders in patients with intracranial bleeding as a result of head injuries or ruptured aneurysms are a diagnostic and therapeutic problem and appropriate assessments are needed to limit CNS damage and to implement preventive measures. The aim of the study was to monitor changes in platelet aggregation and to assess the importance of platelet dysfunction for predicting survival. Platelet receptor function analysis was performed using the agonists arachidonic acid (ASPI), adenosine diphosphate (ADP), collagen (COL), thrombin receptor activating protein (TRAP), ristocetin (RISTO) upon admission to the ICU and on days 2, 3, and 5. On admission, the ASPI, ADP, COL, TRAP, and RISTO tests indicated there was reduced platelet aggregation, despite there being a normal platelet count. In ‘Non-survivors’, the platelet response to all agonists was suppressed throughout the study period, while in ‘Survivors’ it improved. Measuring platelet function in ICU patients with intracranial bleeding is a strong predictor related to outcome: patients with impaired platelet aggregation had a lower 28-day survival rate compared to patients with normal platelet aggregation (log-rank test p = 0.014). The results indicated that measuring platelet aggregation can be helpful in the early detection, diagnosis, and treatment of bleeding disorders.

Working memory training: Taking a step back to retool and create a bridge between clinical and neuroimaging research methods

Improvements in patient outcomes and mortality after brain injury alongside increasing ageing population have resulted in an increasing need to develop cognitive interventions for individuals experiencing changes in their cognitive function. One topic of increasing research interest is whether cognitive functions such as attention, memory and executive functioning can be improved through the use of working memory training interventions. Both clinical and neuroimaging researchers are working to evidence this, but their efforts rarely come together. We discuss here several issues that may be hindering progress in this area, including the tools researchers utilize to measure cognition, the choice between employing active or passive control groups, the focus on transfer effects at the expense of well-characterized training effects, and the overall lack of neuroimaging studies in individuals with neurological disorders. We argue that the only way to advance the field is to build bridges between the disciplines of clinical neuropsychology and cognitive neuroscience. We suggest a multi-level framework to validate the efficacy of working memory interventions and other forms of cognitive training that combine both clinical and neuroimaging approaches. We conclude that in order to move forward we need to form multidisciplinary teams, employ interdisciplinary methods, brain imaging quality rating tools and build national and international collaborations based on open science principles.

Sirtuins, a potential target in Traumatic Brain Injury and relevant experimental models

Traumatic brain injury (TBI) can simply be defined as a violent external injury to the head causing brain dysfunction. The primary injury occurs immediately on impact whereas the secondary injury begins minutes to months after impact. TBI affects a vast majority of population worldwide yet, there isn't any therapeutic intervention available. Sirtuins (SIRTs) are important regulator proteins found in humans. In several neurodegenerative diseases, SIRTs have proven its neuroprotective actions. Owing to the pathophysiological similarities in these diseases and TBI, SIRTs may serve as a potential target for therapeutic intervention in TBI. This review aims to describe the relevance of SIRTs as a potential pharmacological target in TBI. Also, the experimental animal model of TBI explored to understand the role of SIRTs in TBI have been discussed.

Disulfide HMGB1 acts via TLR2/4 receptors to reduce the numbers of oligodendrocyte progenitor cells after traumatic injury in vitro

Traumatic brain injury (TBI) is associated with poor clinical outcomes; autopsy studies of TBI victims demonstrate significant oligodendrocyte progenitor cell (OPC) death post TBI; an observation, which may explain the lack of meaningful repair of injured axons. Whilst high-mobility group box-1 (HMGB1) and its key receptors TLR2/4 are identified as key initiators of neuroinflammation post-TBI, they have been identified as attractive targets for development of novel therapeutic approaches to improve post-TBI clinical outcomes. In this report we establish unequivocal evidence that HMGB1 released in vitro impairs OPC response to mechanical injury; an effect that is pharmacologically reversible. We show that needle scratch injury hyper-acutely induced microglial HMGB1 nucleus-to-cytoplasm translocation and subsequent release into culture medium. Application of injury-conditioned media resulted in significant decreases in OPC number through anti-proliferative effects. This effect was reversed by co-treatment with the TLR2/4 receptor antagonist BoxA. Furthermore, whilst injury conditioned medium drove OPCs towards an activated reactive morphology, this was also abolished after BoxA co-treatment. We conclude that HMGB1, through TLR2/4 dependant mechanisms, may be detrimental to OPC proliferation following injury in vitro, negatively affecting the potential for restoring a mature oligodendrocyte population, and subsequent axonal remyelination. Further study is required to assess how HMGB1-TLR signalling influences OPC maturation and myelination capacity.

Development and Characterization of a Probe Device toward Intracranial Spectroscopy of Traumatic Brain Injury

Traumatic brain injury is a leading cause of mortality worldwide, often affecting individuals at their most economically active yet no primary disease-modifying interventions exist for their treatment. Real-time direct spectroscopic examination of the brain tissue within the context of traumatic brain injury has the potential to improve the understanding of injury heterogeneity and subtypes, better target management strategies and organ penetrance of pharmacological agents, identify novel targets for intervention, and allow a clearer understanding of fundamental biochemistry evolution. Here, a novel device is designed and engineered, delivering Raman spectroscopy-based measurements from the brain through clinically established cranial access techniques. Device prototyping is undertaken within the constraints imposed by the acquisition and site dimensions (standard intracranial access holes, probe’s dimensions), and an artificial skull anatomical model with cortical impact is developed. The device shows a good agreement with the data acquired via a standard commercial Raman, and the spectra measured are comparable in terms of quality and detectable bands to the established traumatic brain injury model. The developed proof-of-concept device demonstrates the feasibility for real-time optical brain spectroscopic interface while removing the noise of extracranial tissue and with further optimization and in vivo validation, such technology will be directly translatable for integration into currently available standards of neurological care.

Bypassing the nearest emergency department for a more distant neurosurgical centre in traumatic brain injury patients

BACKGROUND AND OBJECTIVE

Major trauma triage within regional trauma networks (RTN) select patients with suspected TBI for bypass to specialist neuroscience centres (SNC), expediting neurosurgical care but may delay resuscitation. This comparative effectiveness study assessed the impact of this strategy on the risk adjusted hospital survival rates of patients confirmed to have intracranial injury on brain computed tomography (CT) scan.

METHOD

A retrospective cohort study was conducted using Trauma Audit and Research Network trauma registry data. Adult patients with a TBI on CT scan were included if they presented between June 2015 to February 2016 to SNCs or non-specialist acute hospitals (NSAH) in the North of England (South Cumbria, Lancashire and the North East Region). Patients were identified as having bypassed a nearer NSAH emergency department (ED) to a SNC using google maps. Their standardised excess survival rate was compared to TBI patients who received primary treatment at a NSAH. A multivariate logistic regression model predicting 30-day survival after TBI (Ps14ⁿ)¹ was used to adjust for variation in casemix between cohorts.

STUDY DESIGN AND RESULTS

355 patients met the study inclusion criteria, with 89/355 (25%) of TBI patients bypassing a nearer NSAH to a SNC, and 266/355 (75%) receiving primary treatment at an NSAH. The median severity of intracranial injury was equivalent (median Head Abbreviated Injury Scale 4 (IQR 4-5) in each group. There was no statistically significant difference in the standardised excess survival rate between the two cohorts; +6.15% for bypass (95% CI -1.24% to +13.55%) versus -1.12% for non-bypass (95% CI -4.51% to +2.25%).

CONCLUSION AND FUTURE RESEARCH

No statistically significant survival benefit was identified for TBI patients who bypassed the nearest ED to attend a SNC compared to those receiving treatment at the nearest NSAH, however a clinically significant 7% excess survival rate merits a larger study.

Traumatic brain injury probability of survival assessment in adults using iterative random comparison classification

Trauma brain injury (TBI) is the most common cause of death and disability in young adults. A method to determine the probability of survival (Ps) in trauma called iterative random comparison classification (IRCC) was developed and its performance was evaluated in TBI. IRCC operates by iteratively comparing the test case with randomly chosen subgroups of cases from a database of known outcomes (survivors and not survivors) and determines the overall percentage match. The performance of IRCC to determine Ps in TBI was compared with two existing methods. One was Ps14 that uses regression and the other was predictive statistical diagnosis (PSD) that is based on Bayesian statistic. The TBI database contained 4124 adult cases (mean age 67.9 years, standard deviation 21.6) of which 3553 (86.2%) were survivors and 571 (13.8%) were not survivors. IRCC determined Ps for the survivors and not survivors with an accuracy of 79.0 and 71.4%, respectively, while the corresponding values for Ps14 were 97.4% (survivors) and 40.2% (not survivors) and for PSD were 90.8% (survivors) and 50% (not survivors). IRCC could be valuable for determining Ps in TBI and with a suitable database in other traumas.

Age-Related Changes in the Association Between Traumatic Brain Injury and Dementia in Older Men and Women

OBJECTIVE

To investigate age-related changes in the association between traumatic brain injury (TBI) and dementia in older men and women separately.

SETTING

A total of 243 general practices in the UK.

PARTICIPANTS

This study included 4760 patients who received a first TBI diagnosis between 1995 and 2010 (index date), and 4760 patients without TBI who were matched to those with TBI by age, sex, index year, Charlson Comorbidity Index, alcohol dependence, and physician (index date: a randomly selected visit date).

DESIGN

Retrospective cohort study.

MAIN MEASURES

Incidence of dementia in the decade following index date.

RESULTS

Within 10 years of index date, 8.8% of men with TBI and 4.8% of those without TBI were diagnosed with dementia, while the respective figures were 9.0% and 6.7% in women (P values < .01). There was a significant association between TBI and dementia in men (hazard ratio [HR] = 2.29, 95% confidence interval [CI]: 1.64-3.19) and in women (HR = 1.33, 95% CI: 1.07-1.64). Furthermore, the association between TBI and dementia was significant in men aged 60 to 70 (HR = 2.51, 95% CI: 1.27-4.96) and 71 to 80 years (HR = 3.00, 95% CI: 1.82-4.93), whereas the relationship was only significant and potentially unreliable in women aged 81 to 90 years (HR = 1.49, 95% CI: 1.03-2.14).

CONCLUSIONS

The age-related relationship between TBI and dementia differed between men and women. More research of a prospective nature and including behavioral data is needed to better understand these differences.

End-tidal and arterial carbon dioxide gradient in serious traumatic brain injury after prehospital emergency anaesthesia: a retrospective observational study

OBJECTIVES

In the UK, 20% of patients with severe traumatic brain injury (TBI) receive prehospital emergency anaesthesia (PHEA). Current guidance recommends an end-tidal carbon dioxide (ETCO2) of 4.0-4.5 kPa (30.0-33.8 mm Hg) to achieve a low-normal arterial partial pressure of CO2 (PaCO2), and reduce secondary brain injury. This recommendation assumes a 0.5 kPa (3.8 mm Hg) ETCO2-PaCO2 gradient. However, the gradient in the acute phase of TBI is unknown. The primary aim was to report the ETCO2-PaCO2 gradient of TBI patients at hospital arrival.

METHODS

A retrospective cohort study of adult patients with serious TBI, who received a PHEA by a prehospital critical care team in the East of England between 1 April 2015 and 31 December 2017. Linear regression was performed to test for correlation and reported as R-squared (R2). A Bland-Altman plot was used to test for paired ETCO2 and PaCO2 agreement and reported with 95% CI. ETCO2-PaCO2 gradient data were compared with a two-tailed, unpaired, t-test.

RESULTS

107 patients were eligible for inclusion. Sixty-seven patients did not receive a PaCO2 sample within 30 min of hospital arrival and were therefore excluded. Forty patients had complete data and were included in the final analysis; per protocol. The mean ETCO2-PaCO2 gradient was 1.7 (±1.0) kPa (12.8 mm Hg), with moderate correlation (R2=0.23, p=0.002). The Bland-Altman bias was 1.7 (95% CI 1.4 to 2.0) kPa with upper and lower limits of agreement of 3.6 (95% CI 3.0 to 4.1) kPa and -0.2 (95% CI -0.8 to 0.3) kPa, respectively. There was no evidence of a larger gradient in more severe TBI (p=0.29). There was no significant gradient correlation in patients with a coexisting serious thoracic injury (R2=0.13, p=0.10), and this cohort had a larger ETCO2-PaCO2 gradient, 2.0 (±1.1) kPa (15.1 mm Hg), p=0.01. Patients who underwent prehospital arterial blood sampling had an arrival PaCO2 of 4.7 (±0.2) kPa (35.1 mm Hg).

CONCLUSION

There is only moderate correlation of ETCO2 and PaCO2 at hospital arrival in patients with serious TBI. The mean ETCO2-PaCO2 gradient was 1.7 (±1.0) kPa (12.8 mm Hg). Lower ETCO2 targets than previously recommended may be safe and appropriate, and there may be a role for prehospital PaCO2 measurement.