Management of traumatic brain injury patients

Timely delivery of care in neurological emergencies: can standardized management protocols help?

PURPOSE OF REVIEW

To review the evidence that supports the implementation of goal-directed care bundle protocols to improve outcomes from neurocritical conditions, and of the possible advantage of specific over generalized protocols.

RECENT FINDINGS

Articles from January 1, 2023 to July 31, 2024 were searched to evaluate the effectiveness of standardized management in neurological emergencies. The use of care bundles and standardized protocols with time- and target-related metrics has shown benefit in patients with acute stroke and traumatic brain injury.

SUMMARY

A goal-directed care protocol to guide standard management implemented by a multidisciplinary team can improve outcomes from neurological emergencies. However, implementation challenges need to be addressed before wide adoption of protocolized care for maximum benefit to populations.

Insulin potential in preventing brain damage after traumatic brain injury: What we know

Traumatic brain injury (TBI) is a major global cause of disability and mortality. TBI results in a spectrum of primary and secondary injuries that impact neural function and overall survival. Insulin, beyond its well-known role in regulating blood glucose levels, plays critical roles in the central nervous system (CNS). These roles include the modulation of synaptic plasticity, neurotransmitter levels, neurogenesis, and neuroprotection. Central insulin resistance, a reduced sensitivity to insulin in the brain, has been observed in TBI patients. This insulin resistance impairs insulin function in the brain and increases the risk of neurodegenerative processes. This review will delve into the central role of insulin resistance in the pathological changes observed after TBI and explore the potential benefits of insulin therapy as a treatment approach for TBI.

Integrating Rational Emotive Behavior Therapy, Compassion-Focused Therapy with Cognitive Retraining in Traumatic Brain Injury: A Case Report

BACKGROUND

This case report presents a novel approach to treating Traumatic Brain Injury (TBI) by integrating Rational Emotive Behavior Therapy (REBT), Compassion-Focused Therapy (CFT), and Cognitive Retraining (CR). It contributes to the literature by demonstrating the effectiveness of a comprehensive psychotherapeutic approach in managing complex TBI sequelae, particularly in the Indian context where such interventions are underrepresented.

CASE REPORT

A 34-year-old Indian female presented signs of emotional dysfunction, cognitive impairment, social maladaptation, shamefulness, and self-deprecation following a TBI sustained 10 years prior. A mental status examination and psychological assessments revealed cognitive deficits, emotional instability, and irrational beliefs, all related to her injury and recovery. The treatment plan integrated REBT, to address the irrational beliefs; CFT, to manage the sense of shame and the insistence to self-criticize; and CR, to improve cognitive functions. This approach was tailored to the patient's cognitive limitations and cultural context. Interventions included challenging irrational beliefs, self-compassion imagery, and cognitive exercises adapted to her specific deficits. Outcomes were measured using the Subjective Units of Distress (SUD) scale and clinical observations. The patient showed improvements in emotional regulation, cognitive functioning, and overall quality of life, as evidenced by reduced subjective distress (SUD down from 90 to 58) and enhanced daily functioning.

CONCLUSION

This case demonstrates that an integrated psychotherapeutic approach combining REBT, CFT, and CR can effectively address the complex psychological and cognitive challenges of TBI patients. Tailoring interventions towards patient cognitive limitations and cultural context is crucial for a successful outcome. The case highlights the importance of incorporating diverse therapeutic modalities in TBI management, promoting a more holistic approach to recovery and enhancing the quality of life of TBI survivors.

Administration of monophosphoryl lipid A shortly after traumatic brain injury blocks the following spatial and avoidance memory loss and neuroinflammation

Traumatic brain injury (TBI) frequently leads to cognitive impairments. The toll-like receptor 4 (TLR4) ligand, Monophosphoryl lipid A (MPL), has shown promise in modulating neuroinflammatory responses after TBI. We investigated the effects of MPL on spatial memory, passive avoidance memory, neuronal survival, and inflammatory/anti-inflammatory cytokines in rat brain following mild-to-moderate TBI. Rats underwent a learning period in the Morris water maze and shuttle box, followed by TBI induction by controlled cortical impact. MPL was administered into the cerebral ventricle 20 min after TBI. Spatial memory was assessed 7 and 28 days later. Passive avoidance memory was assessed 2 and 6 days after TBI. MPL significantly improved the spatial memory deficit at 7 days but not 28 days after TBI. It also improved impairment of the avoidance memory at both 2 and 6 days after TBI. MPL prohibited the TBI-induced TNF-α increase and IL-10 decrease in the injured region at 7 days post-TBI period. MPL prevented the neuronal loss induced by TBI in the hippocampus. A single administration of MPL shortly after TBI alleviates short-term memory deficits, through anti-inflammatory and anti-cell loss activities. Repeated MPL administration may also inhibit the long-term memory deficits after TBI.

The impact of brain tissue oxygenation monitoring on the Glasgow Outcome Scale/Glasgow Outcome Scale Extended in patients with moderate to severe traumatic brain injury: A systematic review

BACKGROUND

Traumatic brain injuries (TBIs) are one of the leading causes of death or long-term disability around the world. As a result of improvements in supportive care, patients are surviving more severe insults with more pronounced dependency on their families, hospitals, and long-term care facilities. The introduction of brain tissue oxygenation (PbtO2) monitoring aims to recognize episodes of reduced cerebral perfusion with and without associated increased intracranial pressure (ICP).

AIM

The aim of this review is to determine the impact of PbtO2 on the Glasgow Outcome Scale/Glasgow Outcome Scale Extended (GOS/GOSE) in patients with moderate to severe TBI.

STUDY DESIGN

Systematic review with narrative and meta-analysis. All original research in which adult patients undergoing PbtO2 were compared with a control group of traditional ICP/cerebral perfusion pressure (CPP) monitoring. Both randomized controlled trials and observational studies were included in this review.

METHODS

Databases were searched in September 2022. The primary outcome of the review was the impact of PbtO2 monitoring on GOS/GOSE, while secondary outcomes were mortality and length of stay (LOS) in the intensive care unit (ICU).

RESULTS

Seven studies with a combined number of 770 patients were included in the review. These patients were adults ≥16 years of age. Only two of the studies included found a statistically significant association between PbtO2 monitoring and improved long-term neurological outcomes in patients with TBI (p = .01, p < .01). A meta-analysis of the secondary outcomes identified an associated reduction of mortality in favour of the group treated with PbtO2 monitoring (p < .0001). Results from studies examining LOS in ICU have demonstrated an associated increase of LOS in ICU in patients treated with PbtO2-guided therapy.

CONCLUSION

From the studies included in this review, only two found a statistically significant association between PbtO2 monitoring and long-term outcomes. It is unclear whether PbtO2 goal-directed therapy has a positive impact on the long-term neurological functions and mortality of patients suffering from TBI. A multicentre randomized controlled trial may provide further evidence, but not necessarily conclusive.

RELEVANCE TO CLINICAL PRACTICE

Further research is warranted to determine the efficacy of the introduction of this new monitoring system to guide local policy change.

Effectiveness of hypertonic saline infusion in management of traumatic brain injury: an updated systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

This study aimed to find out the efficacy of using Hypertonic saline solution (HSS) over mannitol in the management of TBI by comparing their performance in improving different outcomes.

METHODS

Electronic databases were searched for randomized controlled trials (RCTs) assessing the impact of HSS vs. mannitol on ICP in patients who suffered TBI. Outcomes of interest were mortality, neurologic functional outcomes, risk ratio (RR) of successful ICP treatment, reduction in ICP after 30-60 and 90-120 min, improvement in cerebral perfusion pressure (CPP) at 30-60 and 90-120 min, and also treatment failure. Evaluations were reported as RR or mean difference (MD) with 95% confidence intervals (CIs) using weighted random-effects models.

RESULTS

The analysis included 624 patients from 15 RCTs. HSS infusion had a significant impact on the improvement of CPP at 30-60 min [MD = 5.54, 95% CI (3.04, 8.03),p < 0.001] compared to mannitol. However, results yielded no significant difference between HSS and mannitol in terms of mortality, neurologic functional outcomes, successful ICP treatment, reduction in ICP after 30-60 min and 90-120 min, improvement in CPP at 90-120 min, and treatment failure.

CONCLUSION

HSS and mannitol are both effective treatments for elevated ICP due to TBI. However, further research is required to derive a better comparison.

Accuracy and time efficiency of a novel deep learning algorithm for Intracranial Hemorrhage detection in CT Scans

PURPOSE

To evaluate a deep learning-based pipeline using a Dense-UNet architecture for the assessment of acute intracranial hemorrhage (ICH) on non-contrast computed tomography (NCCT) head scans after traumatic brain injury (TBI).

MATERIALS AND METHODS

This retrospective study was conducted using a prototype algorithm that evaluated 502 NCCT head scans with ICH in context of TBI. Four board-certified radiologists evaluated in consensus the CT scans to establish the standard of reference for hemorrhage presence and type of ICH. Consequently, all CT scans were independently analyzed by the algorithm and a board-certified radiologist to assess the presence and type of ICH. Additionally, the time to diagnosis was measured for both methods.

RESULTS

A total of 405/502 patients presented ICH classified in the following types: intraparenchymal (n = 172); intraventricular (n = 26); subarachnoid (n = 163); subdural (n = 178); and epidural (n = 15). The algorithm showed high diagnostic accuracy (91.24%) for the assessment of ICH with a sensitivity of 90.37% and specificity of 94.85%. To distinguish the different ICH types, the algorithm had a sensitivity of 93.47% and a specificity of 99.79%, with an accuracy of 98.54%. To detect midline shift, the algorithm had a sensitivity of 100%. In terms of processing time, the algorithm was significantly faster compared to the radiologist's time to first diagnosis (15.37 ± 1.85 vs 277 ± 14 s, p < 0.001).

CONCLUSION

A novel deep learning algorithm can provide high diagnostic accuracy for the identification and classification of ICH from unenhanced CT scans, combined with short processing times. This has the potential to assist and improve radiologists' ICH assessment in NCCT scans, especially in emergency scenarios, when time efficiency is needed.

From spreading depolarization to blood-brain barrier dysfunction: navigating traumatic brain injury for novel diagnosis and therapy

Considerable strides in medical interventions during the acute phase of traumatic brain injury (TBI) have brought improved overall survival rates. However, following TBI, people often face ongoing, persistent and debilitating long-term complications. Here, we review the recent literature to propose possible mechanisms that lead from TBI to long-term complications, focusing particularly on the involvement of a compromised blood-brain barrier (BBB). We discuss evidence for the role of spreading depolarization as a key pathological mechanism associated with microvascular dysfunction and the transformation of astrocytes to an inflammatory phenotype. Finally, we summarize new predictive and diagnostic biomarkers and explore potential therapeutic targets for treating long-term complications of TBI.

Prediction Value of Initial Serum Levels of SERPINA3 in Intracranial Pressure and Long-Term Neurological Outcomes in Traumatic Brain Injury

Traumatic brain injury (TBI) is a severe neurological condition characterized by inflammation in the central nervous system. SERPINA3 has garnered attention as a potential biomarker for assessing this inflammation. Our study aimed to explore the predictive value of postoperative serum SERPINA3 levels in identifying the risk of cerebral edema and its prognostic implications in TBI. This study is a prospective observational study, including 37 patients with TBI who finally met our criteria. The Glasgow Outcome Scale (GOS), Levels of Cognitive Functioning (LCF), Disability Rating Scale (DRS), and Early Rehabilitation Barthel Index (ERBI) scores at six months after trauma were defined as the main study endpoint. We further calculated the ventricle-to-intracranial-volume ratio (VBR) at 6 months from CT scans. The study included patients with Glasgow Coma Scale (GCS) scores ranging from 3 to 8, who were subsequently categorized into two groups: the critical TBI group (GCS 3-5 points) and the severe TBI group (GCS 6-8 points). Within the critical TBI group, SERPINA3 levels were notably lower. However, among patients with elevated SERPINA3 levels, both the peak intracranial pressure (ICP) and average mannitol consumption were significantly reduced compared with those of patients with lower SERPINA3 levels. In terms of the 6-month outcomes measured via the GOS, LCF, DRS, and ERBI, lower levels of SERPINA3 were indicative of poorer prognosis. Furthermore, we found a negative correlation between serum SERPINA3 levels and the VBR. The receiver operating characteristic (ROC) curve and decision curve analysis (DCA) demonstrated the predictive performance of SERPINA3. In conclusion, incorporating the novel biomarker SERPINA3 alongside traditional assessment tools offers neurosurgeons an effective and easily accessible means, which is readily accessible early on, to predict the risk of intracranial pressure elevation and long-term prognosis in TBI patients.

Changes in the levels of serum glial fibrillary acidic protein and the correlation with outcomes in severe traumatic brain injury patients

Purpose

Glial fibrillary acidic protein serves as a biomarker indicative of astroglial injury, particularly following instances of severe traumatic brain injury. This study aims to evaluate variations in serum glial fibrillary acidic protein levels within the first 3 days and their correlation with outcomes in patients with severe traumatic brain injury.

Subjects and methods

Thirty-nine patients with severe traumatic brain injury were enrolled in the study. Their blood samples were collected at six distinct time points: T0 (upon admission), T1, T2, T3, T4, and T5 (6-, 12-, 24-, 48-, and 72-h post-admission, respectively). The blood samples were run for the quantification of serum glial fibrillary acidic protein levels and other biochemical tests. All patients were closely watched and the outcomes at discharge were evaluated.

Results

Glial fibrillary acidic protein levels tend to increase gradually from the time of admission to 48 h post-admission and then decrease at 72 h post-admission. Glial fibrillary acidic protein T2 is correlated with Acute Physiology and Chronic Health Evaluation II score, lactate, Simplified Acute Physiology Score II score and outcome. Glial fibrillary acidic protein max correlated with lactate, Acute Physiology and Chronic Health Evaluation II score, Simplified Acute Physiology Score II score, and outcome. Glasgow Coma Score at admission and glial fibrillary acidic protein T2 (OR = 1.034; p = 0.025), T3 (OR = 1.029; p = 0.046), T4 (OR = 1.006; p = 0.032), T5 (OR = 1.012; p = 0.048) and glial fibrillary acidic protein max (OR = 1.005; p = 0.010) were independent factors that have significant prognostic value in mortality in patients with severe traumatic brain injury. The predictive model in predicting mortality had the highest area under the curve based on glial fibrillary acidic protein T2 and Glasgow Coma Score T0 with an area under the curve of 0.904 and p < 0.001. In the multivariable regression model, glial fibrillary acidic protein max was associated with Glasgow score (p < 0.001; VIF = 1.585), lactate T0 (p = 0.024; VIF = 1.163), Acute Physiology and Chronic Health Evaluation II score (p = 0.037; VIF = 1.360), and Rotterdam score (p = 0.044; VIF = 1.713).

Conclusion

Glial fibrillary acidic protein levels tend to increase gradually from the time of admission to 48 h post-admission then decreases at 72 h post-admission. Glial fibrillary acidic protein T2, T3, T4, T5, and glial fibrillary acidic protein max were independent factors with significant prognostic mortality values in patients with severe traumatic brain injury.

A Modern Approach to the Treatment of Traumatic Brain Injury

Background: Traumatic brain injury manifests itself in various forms, ranging from mild impairment of consciousness to severe coma and death. Traumatic brain injury remains one of the leading causes of morbidity and mortality. Currently, there is no therapy to reverse the effects associated with traumatic brain injury. New neuroprotective treatments for severe traumatic brain injury have not achieved significant clinical success. Methods: A literature review was performed to summarize the recent interdisciplinary findings on management of traumatic brain injury from both clinical and experimental perspective. Results: In the present review, we discuss the concepts of traditional and new approaches to treatment of traumatic brain injury. The recent development of different drug delivery approaches to the central nervous system is also discussed. Conclusions: The management of traumatic brain injury could be aimed either at the pathological mechanisms initiating the secondary brain injury or alleviating the symptoms accompanying the injury. In many cases, however, the treatment should be complex and include a variety of medical interventions and combination therapy.

The emerging importance of skull-brain interactions in traumatic brain injury

The recent identification of skull bone marrow as a reactive hematopoietic niche that can contribute to and direct leukocyte trafficking into the meninges and brain has transformed our view of this bone structure from a solid, protective casing to a living, dynamic tissue poised to modulate brain homeostasis and neuroinflammation. This emerging concept may be highly relevant to injuries that directly impact the skull such as in traumatic brain injury (TBI). From mild concussion to severe contusion with skull fracturing, the bone marrow response of this local myeloid cell reservoir has the potential to impact not just the acute inflammatory response in the brain, but also the remodeling of the calvarium itself, influencing its response to future head impacts. If we borrow understanding from recent discoveries in other CNS immunological niches and extend them to this nascent, but growing, subfield of neuroimmunology, it is not unreasonable to consider the hematopoietic compartment in the skull may similarly play an important role in health, aging, and neurodegenerative disease following TBI. This literature review briefly summarizes the traditional role of the skull in TBI and offers some additional insights into skull-brain interactions and their potential role in affecting secondary neuroinflammation and injury outcomes.

Perioperative management of adults with traumatic brain injury

Despite advances in management strategy, traumatic brain injury remains strongly associated with neurological impairment and mortality. Management of traumatic brain injury requires careful and targeted management of the physiological consequences which extend beyond the scope of the primary impact to the cranium. Here, we present a review of the principles of its acute management in adults. We outline the procedure which patients are assessed and the critical physiological variables which must be monitored to prevent further neurological damage. We describe current interventional strategies from the context of the underlying physiological mechanisms and recent clinical data and identify persisting challenges in traumatic brain injury management and potential avenues of future progress.

Effect of Kencur (Kaempferia galanga L.) Ethanolic Extract Treatment on Cerebral Caspase-3 Expression in Traumatic Brain Injury Rat Models

Background

Traumatic brain injury is one of the most common forms of trauma and causes significant morbidity and mortality. Kencur (Kaempferia galanga L.) ethanolic extract is known to contain substances that could theoretically inhibit unfavourable cellular processes, including oxidative stress and inflammation. This research aimed to study Kencur's anti-apoptosis activity through the inhibition of caspase-3.

Methods

This is a true experimental post-test-only group design study, using male Wistar rats (Ratus novergicus) with weight-drop-induced traumatic brain injury. The subjects in this study were divided into four groups: two Control groups (Groups A and B) and two Therapy groups (Groups C and D). Groups C and D differed in the dose of Kencur ethanolic extract administered (600 mg/kgBW/day and 1,200 mg/kgBW/day, respectively). The Therapy groups were then subdivided into those receiving therapy for 24 h (C-24 and D-24) and those receiving therapy for 48 h (C-48 and D-48). Caspase-3 expression in brain tissue was evaluated at the end of the therapy using immunohistochemistry. All groups were subjected to a Kruskal-Wallis comparison test and the investigation continued with a Mann-Whitney U test to compare the two groups.

Results

In traumatic brain injury rat models treated with Kaempferia galanga L. ethanolic extract at doses of 1,200 mg/kgBW/day within 48 h of therapy (D-48) compared to those who were not treated, there was a significant change in the cerebral expression of caspase-3 (P = 0.016). There was also a significant difference between the two doses of intervention (C-24 at 600 mg/kgBW/day and D-48 at 1,200 mg/kgBW/day; P = 0.016).

Conclusion

With a minimum of 48 h of treatment split into two doses, Kencur (Kaempferia galanga L.) ethanolic extract can decrease caspase-3 expression in rats with traumatic brain injury.

A historical delve into neurotrauma-focused critical care

Neurocritical care is a multidisciplinary field managing patients with a wide range of aliments. Specifically, neurotrauma is a rapidly growing field with increasing demands. The history of how neurotrauma management came to its current form has not been extensively explored before. Our review delves into the history, timeline, and noteworthy pioneers of neurotrauma-focused neurocritical care. We explore the historical development during early times, the 18th-20th centuries, and modern times, as well as warfare- and sports-related concussions. Research is ever growing in this budding field, with several promising innovations on the horizon.

Validation and characterization of a novel blood-brain barrier platform for investigating traumatic brain injury

The Blood-Brain Barrier (BBB) is a highly-selective physiologic barrier responsible for maintaining cerebral homeostasis. Innovative in vitro models of the BBB are needed to provide useful insights into BBB function with CNS disorders like traumatic brain injury (TBI). TBI is a multidimensional and highly complex pathophysiological condition that requires intrinsic models to elucidate its mechanisms. Current models either lack fluidic shear stress, or neglect hemodynamic parameters important in recapitulating the human in vivo BBB phenotype. To address these limitations in the field, we developed a fluid dynamic novel platform which closely mimics these parameters. To validate our platform, Matrigel-coated Transwells were seeded with brain microvascular endothelial cells, both with and without co-cultured primary human astrocytes and bone-marrow mesenchymal stem cells. In this article we characterized BBB functional properties such as TEER and paracellular permeability. Our platform demonstrated physiologic relevant decreases in TEER in response to an ischemic environment, while directly measuring barrier fluid fluctuation. These recordings were followed with recovery, implying stability of the model. We also demonstrate that our dynamic platform is responsive to inflammatory and metabolic cues with resultant permeability coefficients. These results indicate that this novel dynamic platform will be a valuable tool for evaluating the recapitulating BBB function in vitro, screening potential novel therapeutics, and establishing a relevant paradigm to evaluate the pathophysiology of TBI.

Development and Validation of an XGBoost-Algorithm-Powered Survival Model for Predicting In-Hospital Mortality Based on 545,388 Isolated Severe Traumatic Brain Injury Patients from the TQIP Database

BACKGROUND

Traumatic brain injury (TBI) represents a significant global health issue; the traditional tools such as the Glasgow Coma Scale (GCS) and Abbreviated Injury Scale (AIS) which have been used for injury severity grading, struggle to capture outcomes after TBI.

AIM AND METHODS

This paper aims to implement extreme gradient boosting (XGBoost), a powerful machine learning algorithm that combines the predictions of multiple weak models to create a strong predictive model with high accuracy and efficiency, in order to develop and validate a predictive model for in-hospital mortality in patients with isolated severe traumatic brain injury and to identify the most influential predictors. In total, 545,388 patients from the 2013-2021 American College of Surgeons Trauma Quality Improvement Program (TQIP) database were included in the current study, with 80% of the patients used for model training and 20% of the patients for the final model test. The primary outcome of the study was in-hospital mortality. Predictors were patients' demographics, admission status, as well as comorbidities, and clinical characteristics. Penalized Cox regression models were used to investigate the associations between the survival outcomes and the predictors and select the best predictors. An extreme gradient boosting (XGBoost)-powered Cox regression model was then used to predict the survival outcome. The performance of the models was evaluated using the Harrell's concordance index (C-index). The time-dependent area under the receiver operating characteristic curve (AUC) was used to evaluate the dynamic cumulative performance of the models. The importance of the predictors in the final prediction model was evaluated using the Shapley additive explanations (SHAP) value.

RESULTS

On average, the final XGBoost-powered Cox regression model performed at an acceptable level for patients with a length of stay up to 250 days (mean time-dependent AUC = 0.713) in the test dataset. However, for patients with a length of stay between 20 and 213 days, the performance of the model was relatively poor (time-dependent AUC < 0.7). When limited to patients with a length of stay ≤20 days, which accounts for 95.4% of all the patients, the model achieved an excellent performance (mean time-dependent AUC = 0.813). When further limited to patients with a length of stay ≤5 days, which accounts for two-thirds of all the patients, the model achieved an outstanding performance (mean time-dependent AUC = 0.917).

CONCLUSION

The XGBoost-powered Cox regression model can achieve an outstanding predictive ability for in-hospital mortality during the first 5 days, primarily based on the severity of the injury, the GCS on admission, and the patient's age. These variables continue to demonstrate an excellent predictive ability up to 20 days after admission, a period of care that accounts for over 95% of severe TBI patients. Past 20 days of care, other factors appear to be the primary drivers of in-hospital mortality, indicating a potential window of opportunity for improving outcomes.

Clinical Theragnostic Signature of Extracellular Vesicles in Traumatic Brain Injury (TBI)

Traumatic brain injury (TBI) is a common cause of disability and fatality worldwide. Depending on the clinical presentation, it is a type of acquired brain damage that can be mild, moderate, or severe. The degree of patient's discomfort, prognosis, therapeutic approach, survival rates, and recurrence can all be strongly impacted by an accurate diagnosis made early on. The Glasgow Coma Scale (GCS), along with neuroimaging (MRI (Magnetic Resonance Imaging) and CT scan), is a neurological assessment tools used to evaluate and categorize the severity of TBI based on the patient's level of consciousness, eye opening, and motor response. Extracellular vesicles (EVs) are a growing domain, explaining neurological complications in a more detailed manner. EVs, in general, play a role in cellular communication. Its molecular signature such as DNA, RNA, protein, etc. contributes to the status (health or pathological stage) of the parental cell. Brain-derived EVs support more specific screening (diagnostic and prognostic) in TBI research. Therapeutic impact of EVs are more promising for aiding in TBI healing. It is nontoxic, biocompatible, and capable of crossing the blood-brain barrier (BBB) to transport therapeutic molecules. This review has highlighted the relationships between EVs and TBI theranostics, EVs and TBI-related clinical trials, and related research domain-associated challenges and solutions. This review motivates further exploration of associations between EVs and TBI and develops a better approach to TBI management.

Single Versus Repetitive Traumatic Brain Injury: Current Knowledge on the Chronic Outcomes, Neuropathology and the Role of TDP-43 Proteinopathy

Traumatic brain injury (TBI) is one of the most important causes of death and disability in adults and thus an important public health problem. Following TBI, secondary pathophysiological processes develop over time and condition the development of different neurodegenerative entities. Previous studies suggest that neurobehavioral changes occurring after a single TBI are the basis for the development of Alzheimer's disease, while repetitive TBI is considered to be a contributing factor for chronic traumatic encephalopathy development. However, pathophysiological processes that determine the evolvement of a particular chronic entity are still unclear. Human post-mortem studies have found combinations of amyloid, tau, Lewi bodies, and TAR DNA-binding protein 43 (TDP-43) pathologies after both single and repetitive TBI. This review focuses on the pathological changes of TDP-43 after single and repetitive brain traumas. Numerous studies have shown that TDP-43 proteinopathy noticeably occurs after repetitive head trauma. A relatively small number of available preclinical research on single brain injury are not in complete agreement with the results from the human samples, which makes it difficult to draw specific conclusions. Also, as TBI is considered a heterogeneous type of injury, different experimental trauma models and injury intensities may cause differences in the cascade of secondary injury, which should be considered in future studies. Experimental and post-mortem studies of TDP-43 pathobiology should be carried out, preferably in the same laboratories, to determine its involvement in the development of neurodegenerative conditions after one and repetitive TBI, especially in the context of the development of new therapeutic options.

Early neuro-rehabilitation in traumatic brain injury: the need for an African perspective

BACKGROUND

Traumatic brain injury (TBI) is a global public health challenge, affecting about 69 million individuals annually and being one of the leading causes of mortality. It has adverse consequences in terms of cognitive and physical functioning, which makes rehabilitation interventions an integral part of its management. Early neuro-rehabilitation guidelines for traumatic brain injury have not yet been developed and implemented in most of Africa especially Sub-Saharan Africa. BODY: We aimed with this Opinion to propose a collective reflection on the development and implementation of early neuro-rehabilitation guidelines as an integral part of the care in traumatic brain injury. The different aspects to be considered for reflection have been highlighted: Traumatic brain injury severity to be considered in early neuro-rehabilitation; who should be assessed and receive early neurorehabilitation, barriers to be considered for early neurorehabilitation; what early neurorehabilitation to be considered; the different phases involved in rehabilitation after mild, moderate, and severe TBI; and lastly, what perspective for the creation of neurorehabilitation teams. In conclusion, neuro-rehabilitation should start at the time of admission and should continue from the intensive care unit through the community for the moderate-to-severe traumatic brain injury population. However, mild TBI should also be considered for long-term follow-up in the community due to the fact that some mild traumatic brain injury patients might develop chronic cognitive problems or fatigue with time.

CONCLUSION

Neurorehabilitation should start at the time of admission and continue from the intensive care unit through the community for the moderate-to-severe traumatic brain injury population. There is a need to develop, agree on, and implement guidelines on early neuro-rehabilitation interventions for patients with moderate to severe traumatic brain injury in the African region, where disparities in care are common reality.

A Swine Model of Changes in the Neuronal Electromagnetic Field After Traumatic Brain Injury: A Pilot Study

Background Traumatic brain injury (TBI) is a global cause of disability and mortality. Treatment depends on mitigation of secondary injury resulting in axonal injury, necrosis, brain dysfunction, and disruption of electrical and chemical signaling in neural circuits. To better understand TBI, translational models are required to study physiology, diagnostics, and treatments in homologous species, such as swine. Electromagnetic fields (EMFs) from altered neural circuits can be measured and historically have been reliant on expensive shielding and supercooling in magnetoencephalography. Using proprietary induction sensors, it has been found that a non-invasive, non-contact approach with an engineered Mu-metal and copper mesh-shielded helmet effectively measures EMFs. This has not yet been investigated in swine models. We wished to evaluate the efficacy of this technology to assess TBI-dependent EMF changes in swine to describe the efficacy of these sensors and this model using a gravity-dependent controlled cortical impact (CCI). Methods A Yucatan miniswine was evaluated using non-contact, non-invasive proprietary induction sensors with an engineered dual-layer Mu-metal and interlaced copper mesh helmet with sensors within EMF channels connected to a helmet. Swine EMF recordings were obtained prior to induced gravity-dependent CCI followed by post-TBI measurements. Behavioral changes and changes in EMF measurements were assessed. EMF measurements were evaluated with an artificial intelligence (AI) model. Results Differences between room "noise" EMF measurements and pre-TBI swine electromagnetic field measurements were identified. Morphological characteristics between pre-injury and post-injury measurements were noted. AI modeling differentiated pre-injury and post-injury patterns in the swine EMF. Frequently identified frequencies seen post-injury were peaks at 2.5 Hz and 6.5 Hz and a valley at 11 Hz. The AI model identified less changes in the slope and thus decreased variation of EMF measurements post-TBI between 4.5 Hz and 7 Hz. Conclusions For the first time, it was identified that cortical function in a swine can be appropriately measured using novel induction sensors and shielding isolated to a helmet and EMF channels. The swine model can be appropriately differentiated from the external noise signal with identifiably different pre-injury and post-injury EMFs. Patterns can be recognized within the post-injury EMF due to altered neural circuits that can be measured using these sensors continuously, non-invasively, and in real time.

Prevalence of comorbidities post mild traumatic brain injuries: a traumatic brain injury model systems study

Traumatic brain injury (TBI) is associated with an increased risk of long-lasting health-related complications. Survivors of brain trauma often experience comorbidities which could further dampen functional recovery and severely interfere with their day-to-day functioning after injury. Of the three TBI severity types, mild TBI constitutes a significant proportion of total TBI cases, yet a comprehensive study on medical and psychiatric complications experienced by mild TBI subjects at a particular time point is missing in the field. In this study, we aim to quantify the prevalence of psychiatric and medical comorbidities post mild TBI and understand how these comorbidities are influenced by demographic factors (age, and sex) through secondary analysis of patient data from the TBI Model Systems (TBIMS) national database. Utilizing self-reported information from National Health and Nutrition Examination Survey (NHANES), we have performed this analysis on subjects who received inpatient rehabilitation at 5 years post mild TBI. Our analysis revealed that psychiatric comorbidities (anxiety, depression, and post-traumatic stress disorder (PTSD)), chronic pain, and cardiovascular comorbidities were common among survivors with mild TBI. Furthermore, depression exhibits an increased prevalence in the younger compared to an older cohort of subjects whereas the prevalence of rheumatologic, ophthalmological, and cardiovascular comorbidities was higher in the older cohort. Lastly, female survivors of mild TBI demonstrated increased odds of developing PTSD compared to male subjects. The findings of this study would motivate additional analysis and research in the field and could have broader implications for the management of comorbidities after mild TBI.

Inflammation and immunomodulation in central nervous system injury - B cells as a novel therapeutic opportunity

Acute injury to the central nervous system (CNS) remains a complex and challenging clinical need. CNS injury initiates a dynamic neuroinflammatory response, mediated by both resident and infiltrating immune cells. Following the primary injury, dysregulated inflammatory cascades have been implicated in sustaining a pro-inflammatory microenvironment, driving secondary neurodegeneration and the development of lasting neurological dysfunction. Due to the multifaceted nature of CNS injury, clinically effective therapies for conditions such as traumatic brain injury (TBI), spinal cord injury (SCI), and stroke have proven challenging to develop. No therapeutics that adequately address the chronic inflammatory component of secondary CNS injury are currently available. Recently, B lymphocytes have gained increasing appreciation for their role in maintaining immune homeostasis and regulating inflammatory responses in the context of tissue injury. Here we review the neuroinflammatory response to CNS injury with particular focus on the underexplored role of B cells and summarize recent results on the use of purified B lymphocytes as a novel immunomodulatory therapeutic for tissue injury, particularly in the CNS.

Factors Associated with Adverse Outcomes in Cameroonian Patients with Traumatic Brain Injury: A Cross-Sectional Study

BACKGROUND

The burden of traumatic brain injury (TBI) disproportionately affects low- and middle-income countries. In Cameroon, the estimated annual incidence rate is 572 cases per 100,000 people. This study investigated factors associated with adverse outcomes in the management of Cameroonian patients with TBI.

METHODS

This cross-sectional study included all patients with TBI treated between January 1 and December 31, 2018, at 2 Cameroonian referral hospitals. Sociodemographic and clinical data were extracted from patient charts and admission registries and analyzed with SPSS v.26. Independent t tests, odds ratios, and cumulative mortality hazard rates were computed. A P-value <0.05 was considered statistically significant. Also, binomial regression analyses were calculated.

RESULTS

One hundred seventy-one patients aged 38.63 ± 20.46 years old received treatment for TBI. Most patients were male (78.9%), Cameroonian (98.2%), from urban areas (75.4%), and uninsured (88.8%). The average admission length was 11.23 ± 10.71 days, during which 27.5% of patients received surgical treatment while 72.5% received non-surgical (conservative) management. From postdischarge day 12 onwards, surgically-treated patients had a greater cumulative mortality hazard rate than conservatively-treated patients. By 28 days postdischarge, 66.1% of patients had recovered completely [Glasgow Outcome Scale (GOS) = 5], 23.4% had a disability (GOS = 2-4), and 10.5% expired (GOS = 1). Complete recovery was associated with the absence of severe TBI (B = -1.42, standard error [SE] = 0.52, P = 0.006), disability was associated with increased injury-to-admission delay (B = -1.27, SE = 0.48, P = 0.009), and death was associated with severe TBI (B = 3.16, SE = 0.73, P < 0.001).

CONCLUSIONS

We identified factors associated with unfavorable outcomes among Cameroonian patients with TBI. These results can inform triage and referral practices and aid policymakers in developing context-specific prehospital guidelines.

Neutrophil to Lymphocyte Ratio as a Predictor of Postoperative Outcomes in Traumatic Brain Injury: A Systematic Review and Meta-Analysis

(1) Introduction: Traumatic brain injury (TBI) is a leading cause of injury and mortality worldwide, carrying an estimated cost of $38 billion in the United States alone. Neutrophil to lymphocyte ratio (NLR) has been investigated as a standardized biomarker that can be used to predict outcomes of TBI. The aim of this review was to determine the prognostic utility of NLR among patients admitted for TBI. (2) Methods: A literature search was conducted in PubMed, Scopus, and Web of Science in November 2022 to retrieve articles regarding the use of neutrophil to lymphocyte ratio (NLR) as a prognostic measure in traumatic brain injury (TBI) patients. Inclusion criteria included studies reporting outcomes of TBI patients with associated NLR values. Exclusion criteria were studies reporting only non-primary data, those insufficiently disaggregated to extract NLR data, and non-English or cadaveric studies. The Newcastle-Ottawa Scale was utilized to assess for the presence of bias in included studies. (3) Results: Following the final study selection 19 articles were included for quantitative and qualitative analysis. The average age was 46.25 years. Of the 7750 patients, 73% were male. Average GCS at presentation was 10.51. There was no significant difference in the NLR between surgical vs. non-surgical cohorts (SMD 2.41 95% CI −1.82 to 6.63, p = 0.264). There was no significant difference in the NLR between bleeding vs. non-bleeding cohorts (SMD 4.84 95% CI −0.26 to 9.93, p = 0.0627). There was a significant increase in the NLR between favorable vs. non-favorable cohorts (SMD 1.31 95% CI 0.33 to 2.29, p = 0.0090). (4) Conclusions: Our study found that NLR was only significantly predictive for adverse outcomes in TBI patients and not surgical treatment or intracranial hemorrhage, making it nonetheless an affordable alternative for physicians to assess patient prognosis.

Neurostimulation for Traumatic Brain Injury: Emerging Innovation

Traumatic brain injury (TBI) is a significant source of brain deficit and death among neurosurgical patients, with limited prospects for functional recovery in the cases of moderate-to-severe injury. Until now, the relevant body of literature on TBI intervention has focused on first-line, invasive treatment options (namely craniectomy and hematoma evacuation) with underwhelming focus on non-invasive therapies following surgical stabilization. Recent advances in our understanding of the impaired brain have encouraged deeper investigation of neurostimulation strategies, owed largely to its demonstrated livening of damaged neural circuitry and capacity to stabilize erratic network activity. The objective of the present study is to provide a scoping review of new knowledge in neurostimulation published in the PubMed, Scopus, and Google Scholar databases from inception to November 2022. We critically assess and appraise the available data on primary neurostimulation delivery techniques, with marked emphasis on restorative opportunities for accessory neurostimulation in the interdisciplinary care of moderate-to-severe TBI (msTBI) patients. These data identify two primary future directions: 1) to relate obtained gain-of-function outcomes to hemodynamic and histological changes and 2) to develop a clearer understanding of neurostimulation efficacy, when combined with pharmacologic interventions or other modulatory techniques, for complex brain insult.

Mapping access to care and identification of barriers for traumatic brain injury in a South African township

RATIONALE

South Africa has a high traumatic injury burden resulting in a significant number of persons suffering from traumatic brain injury (TBI). TBI is a time-sensitive condition requiring a responsive and organized health system to minimize morbidity and mortality. This study outlined the barriers to accessing TBI care in a South African township.

METHODS

This was a multimethod study. A facility survey was carried out on health facilities offering trauma care in Khayelitsha township, Cape Town, South Africa. Perceived barriers to accessing TBI care were explored using qualitative interviews and focus group discussions. The four-delay framework that describes delays in four phases was used: seeking, reaching, receiving, and remaining in care. We purposively recruited individuals with a history of TBI (n = 6) and 15 healthcare professionals working with persons with TBI (seven individuals representing each of the five facilities, the heads of neurosurgery and emergency medical services and eight additional healthcare providers who participated in the focus group discussions). Quantitative data were analysed descriptively while qualitative data were analysed thematically, following inductive and deductive approaches.

FINDINGS

Five healthcare facilities (three community health centres, one district hospital and one tertiary hospital) were surveyed. We conducted 13 individual interviews (six with persons with TBI history, seven with healthcare providers from each of the five facilities, neurosurgery department and emergency medical service heads and two focus group discussions involving eight additional healthcare providers. Participants mentioned that alcohol abuse and high neighbourhood crime could lead to delays in seeking and reaching care. The most significant barriers reported were related to receiving definitive care, mostly due to a lack of diagnostic imaging at community health centres and the district hospital, delays in interfacility transfers due to ambulance delays and human and infrastructural limitations. A barrier to remaining in care was the lack of clear communication between persons with TBI and health facilities regarding follow-up care.

CONCLUSION

Our study revealed that various individual-level, community and health system factors impacted TBI care. Efforts to improve TBI care and reduce injury-related morbidity and mortality must put in place more community-level security measures, institute alcohol regulatory policies, improve access to diagnostics and invest in hospital infrastructures.

Multiplex Assessment of Serum Chemokines CCL2, CCL5, CXCL1, CXCL10, and CXCL13 Following Traumatic Brain Injury

Chemokines may promote neuroinflammation following traumatic brain injury (TBI), thereby exacerbating secondary injury. This study was designed to investigate the contributions of chemokines (CCL2, CCL5, CXCL1, CXCL10, and CXCL13) to TBI severity and clinical outcome. Peripheral blood was drawn from 92 TBI patients on admission, and 40 controls were recruited. Serum concentrations of CCL2, CCL5, CXCL1, CXCL10, and CXCL13 on admission were measured by ELISA. Preoperative clinical severity was evaluated using the Glasgow Coma Scale (GCS), and clinical outcome at 90 days post-TBI was evaluated using the Glasgow Outcome Scale (GOS). The associations were evaluated by calculating Spearman's correlation coefficients. A binary logistic regression model was used to identify clinicodemographic factors influencing outcome, and ROC curves were constructed. Serum concentrations of CCL2, CCL5, CXCL1, CXCL10, and CXCL13 were elevated significantly after TBI and negatively correlated with GCS and GOS scores except CCL5. CCL2 may be considered as an independent predictor to predict severity and outcome. Moreover, combination of GCS score, CCL2, and CXCL10 can be a better assessment prognosis of moderate and severe TBI.

Correlation of MLR with CRP and MPVPCR with LED in Traumatic Brain Injury

BACKGROUND: Traumatic brain injury (TBI) contributes greatly to high rates of death and disability globally. It may be divided into primary and secondary injuries. Primary head injuries occur at the moment of impact which causes mechanical loads and accelerations both linearly and rotationally, causing injury to the brain. After the primary brain injury, further biochemical and cellular processes occur that lead to secondary injury. Secondary insult in TBI may lead to several neuroinflammation processes that are reflected on laboratory markers. The monocyte-lymphocyte ratio and mean platelet volume-platelet count ratio (MPVPCR) theoretically have the potential to be used as neuroinflammation markers in TBI. AIM: This study was conducted to assess the relationship between monocyte-lymphocyte ratio (MLR), MPVPCR with both C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) regarded as inflammation markers in relation to secondary brain injury. METHODS: This study was a cross-sectional prospective analytic observational study conducted at the Sanglah hospital emergency department from February to May 2022. Patients diagnosed with TBI aged 18 years and over that were willing to be included in the study by consecutive sampling. Patients with a history of autoimmune disease, history of taking immunosuppressant drugs, and fractures of > 2 long bones were excluded and the presence of infection characterized by fever was excluded from the study. History taking and physical examination were done to obtain data regarding age, gender, mechanism of injury, Glasgow Coma Scale, fainting duration, and memory loss. The blood sample was taken at 24 h after trauma to obtain MLR, MPVPCR, CRP, and ESR results. Pearson correlation test was done to determine the correlation between MLR and MPVPCR with CRP and LED. RESULTS: There are a total of 85 patients included in this study with the mean of age which is 36 ± 2.5 years old. Most of them are men (71.3%) with the mean of GCS on admission which is 12. Mean ± (SD) of the monocyte, lymphocyte, and platelet was 1.12 ± 0.82 × 103/μL, 1.83 ± 1.69 × 103/μL, and 259.34 ± 85.79 × 103/μL consecutively. MLR with CRP had a weak positive correlation and was statistically significant (r = 0.215; p = 0.045), as well as MPVPCR with ESR also had a weak positive correlation and was statistically significant (r = 0.276; p = 0.010). While both MLR with ESR and MPVPCR with CRP had no correlation. CONCLUSION: MLR can be an option representing CRP in predicting the magnitude of inflammation in head injury and MPVPCR can be considered to be used as a predictor of thrombotic phenomena in TBI.

Rehabilitation among individuals experiencing homelessness and traumatic brain injury: A scoping review

Traumatic brain injury (TBI) is disproportionately prevalent among individuals experiencing homelessness. While rehabilitation is critical to facilitating recovery after TBI, there is currently limited information on the extent to which rehabilitation is provided to individuals experiencing homelessness and TBI. If unaddressed, this knowledge gap can perpetuate TBI-related challenges and contribute to a repetitive cycle of TBI and homelessness. This scoping review explored the extent to which rehabilitation, including the types of rehabilitation interventions, are available to, or used by, individuals experiencing homelessness and TBI. A systematic search of electronic databases (MEDLINE, Embase, Cochrane CENTRAL Register of Clinical Trials, CINAHL, APA PsycINFO, Applied Social Sciences Index and Abstracts, and Proquest Nursing and Allied Health) was conducted to identify peer-reviewed articles that met predetermined eligibility criteria. Gray literature and reference lists of eligible articles were also searched for relevant content. A descriptive numerical summary of extracted data was conducted, and qualitative analytic techniques were applied to analyze the data. Fifteen peer-reviewed articles and three gray literature reports were included, describing interventions for individuals experiencing homelessness and TBI (N = 4), rehabilitation for individuals experiencing homelessness without specific inclusion criteria for TBI (N = 11), and rehabilitation interventions that included individuals experiencing homelessness and TBI, without specific inclusion criteria for experiences of homelessness or TBI (N = 3). This review demonstrates that rehabilitation programs or interventions for this population already exist, and those that are focused on individuals experiencing homelessness are already serving individuals with TBI. Findings highlight opportunities to adapt existing rehabilitation for individuals who experience homelessness and TBI through screening for TBI, conducting cognitive and functional assessments, and tailoring interventions with multidisciplinary teams. Education and training for healthcare professionals working with individuals experiencing homelessness and TBI should be explored, including structured education and training, collaboration with a multidisciplinary team, and co-development of educational materials with service users. Research that considers the rehabilitation needs of diverse individuals experiencing homelessness and TBI is urgently needed.

Prevalence and Outcomes of Geriatric Traumatic Brain Injury in Developing Countries: A Retrospective Study

Introduction The world populace is aging and it is anticipated that 2 billion people will be older than 60 years by 2050. Traumatic brain injury (TBI) is a major cause of death and disability worldwide. In the United States, 2.8 million people pursue medical attention yearly. TBI exemplifies a leading cause of mortality and morbidity among the geriatric age group worldwide.

Methods A retrospective study of geriatric cases who were admitted to the Neurosurgery Department in Khoula Hospital from January 1, 2016, to December 31, 2019, was conducted. Patients' demographics, risk factors, neuro-vital sign, diagnosis, Glasgow coma scale (GCS) on arrival, treatment types, and length of stay (LOS) were recorded.

Results Two hundred and thirty-four patients were admitted due to TBI in four years period. Seventy-five percent of the study cohort were more than 75 years old. Male to female ratio was 2.4:1. Subdural hematoma (SDH) was the most common TBI diagnosis based on computed tomography (77.4%). Most of the patients were having GCS scores of 14 to 15 (67.9%). Sixteen percent of the patients received antiepileptic medications. The majority of the patients underwent surgical intervention (70.5%). Eighty percent of the patients stayed in the hospital for less than 15 days. There was a significant difference between the LOS and type of surgery. Subarachnoid hemorrhage was found to have the highest mean age (79.7 years). Intracerebral hemorrhage patients had the longest LOS in the hospital with a mean of 44.2 days. There was no significant difference between the age of patients and type of surgery.

Conclusion The number of TBI in the elderly population is increasing annually. The most common type of TBI in our cohort was SDH and most of the patients were treated with burr hole surgery.

Surgical Management of Neurotrauma: When to Intervene

Neurotrauma, often defined as abrupt damage to the brain or spinal cord, is a substantial cause of mortality and morbidity that is widely recognized. As such, establishing an effective course of action is crucial to the enhancement of neurotrauma guidelines and patient outcomes in healthcare worldwide. Following the onset of neurotraumatic injuries, time is perhaps the most critical facet in diminishing mortality and morbidity rates. Thus, procuring the airway should be of utmost priority in a patient to allow for optimal ventilation, with a shift in focus resorting to surgical interventions after the patient reaches a suitable care facility. In particular, ventriculoperitoneal shunt (VPS) procedures have long been utilized to treat traumatic brain and spinal cord injuries to direct additional cerebrospinal fluid (CSF) from the lateral ventricles through a ventricular catheter attached to a valve that is further connected to a distal catheter. Decompressive cranio omie (DCs), cranioplasties, and intracranial pressure measurements (ICP) are also frequently performed in combination with VPS to manage intracranial hypertension and cerebral edema. Although the current surgical methods utilized in the treatment of neurotrauma prove to be highly efficacious in the prevention of adverse outcomes, emergent therapies are growing in popularity. Of interest, the Three Pillars Expansive Craniotomy, cisternostomy, and external lumbar drainages are cutting-edge procedures with promising results that can potentially usher change in the neurosurgical industry but require additional examination.

Advocacy for Change: An Osteopathic Review of Traumatic Brain Injury Among Combat Veterans

As a "signature injury" of the Iraq and Afghanistan wars, traumatic brain injury (TBI) remains a major health concern among military service members. Traumatic brain injury is associated with a wide range of symptoms which may be cognitive, emotional, psychological, biochemical, and social in nature. Mild TBI (mTBI) ranks as the most common traumatic brain injury among veterans. Due to the absence of specific symptoms, mTBI diagnosis may be challenging in acute settings. Repetitive traumatic brain injury during combat deployments can lead to devastating chronic neurodegenerative diseases and other major life disruptions. Many cases of TBI remain undetected in veterans and may lead to long-term adverse comorbidities such as post-traumatic stress disorder (PTSD), suicide, alcohol disorders, psychiatric diagnoses, and service-related somatic dysfunctions. Veterans with TBI are almost twice as likely to die from suicide in comparison to veterans without a history of TBI. Veterans diagnosed with TBI experience significant comorbid conditions and thus advocacy for improved care is justified and necessary. Given the complexity and variation in the symptomatology of TBI, a personalized, multimodal approach is warranted in the evaluation and treatment of veterans with TBI and other associated conditions. As such, this review provides a broad overview of treatment options, with an emphasis on advocacy and osteopathic integration in the standard of care for veterans.

A Cohort Study to Assess Cognitive Impairment and Its Effects on Older Patients in the Orthopedic Rehabilitation

Background

The cognitive role of older patients is regularly not investigated in orthopedic rehabilitation, after the elective as well as the nonelective operation. The objective of this research is to investigate the cognitive disorder and its influence over the duration of stay along with the functional consequences of the older patients who were admitted to orthopedic rehabilitation. Material and Methods. The inclusion criteria for this study were the patients with age above 50 years; who were admitted with the detection of orthopedic impairment and the surgery both elective and nonelective, investigated utilizing the MoCA (Montreal Cognitive Assessment) over admission, MBI (Modified Barthel Index), and FIM (Function Independent Measure) over admission and discharge status; and were discharged from the hospital. The demography, as well as the clinical data, comprising of the duration of stay, age and the detection was also reported.

Result

Of the 109 admitted patients, 80 patients were included in the study where n = 47 (58.75%) patients were females and n = 33 (41.25%) were males. The age group range was 50 to 94 years with a mean age of 78.5 years (SD = 8.27). The diagnostic groups included for the study were fractured neck of femur (n = 34; 42.5%), orthopedic surgery (n = 22; 27.5%), and other orthopedic surgery (n = 24; 30%). The mean duration of rehabilitation stay was reported as 34 (4.39), where the MoCA was reported as 22.17 (2.44); functional independence measures were as follows: motor admission as 53.97 (7.55), motor discharge as 76.27 (5.35), cognitive admission as 30.71 (1.99), and cognitive discharge as 31.85 (1.94). Here, the diagnosis was done over the fractured neck of the femur (i.e., NOF being 34 (42.5%), elective surgeries 22 (27.5%), and other orthopedic as 24 (30%)).

Conclusion

An excessive percentage of older-age patients in a rehabilitation unit with elective as well as nonelective diagnoses comprises the cognitive disorder. The cognitive screening was advised for all the older age patients in the rehabilitation units to report a specific rehabilitation plan to enhance the consequences along with the duration of stay. There is further study required to explore different cognitive strategies to enhance the rehabilitation consequences among older-age orthopedic patients.

Factors Affecting Neurosurgeons' Decisions to Forgo Life-Sustaining Treatments After Traumatic Brain Injury

BACKGROUND

Traumatic brain injury (TBI) is a multifaceted condition that causes mortality and disability worldwide. Limited data are available on the factors associated with the decision for the withdrawal of life-sustaining treatment (WLST) for patients with TBI. In the present study, we aimed to determine the risk factors and attitudes affecting neurosurgeons when deciding on WLST for patients with TBI using a multicenter survey.

METHODS

An online questionnaire was applied worldwide and shared using social media platforms and electronic mail to ∼5000 neurosurgeons. The social media group "Neurosurgery Cocktail" was used to post a link to the questionnaire. In addition, randomly chosen neurosurgery clinics around the world were sent the survey via electronic mail.

RESULTS

Of the participants, 17.22% had decided on WLST after TBI for >26 patients. Neurosurgeons with more WLST decisions were older, had had more clinical experience and intensive care unit (ICU) training, and were better prepared to involve the family members of TBI patients in their decision-making compared with those with fewer WLST decisions. The respondents stated that the patient's family, ICU consultants, and themselves played the most influential role in the WLST decisions, with the hospital administration, social workers, spiritual caregivers, and nurses having lesser roles. The current and presenting Glasgow coma scale scores, pupillary response, advanced patient age, candidates for a vegetative state, and impaired neurological function were significant factors associated with the WLST decision.

CONCLUSIONS

To the best of our knowledge, the present study is the first to evaluate neurosurgeons concerning their opinions and behaviors regarding WLST decisions after TBI. Increased patient age, Glasgow coma scale score, pupillary response, the presence of comorbidities, candidacy for a vegetative state, and impaired neurological function were the main factors contributing to the decision for WLST. We also found that the family, ICU consultants, and the attending neurosurgeon had the most effective roles in the decisions regarding WLST.

The Clinical Use of Serum Biomarkers in Traumatic Brain Injury: A Systematic Review Stratified by Injury Severity

BACKGROUND

Serum biomarkers have gained significant popularity as an adjunctive measure in the evaluation and prognostication of traumatic brain injury (TBI). However, a concise and clinically oriented report of the major markers in function of TBI severity is lacking. This systematic review aims to report current data on the diagnostic and prognostic utility of blood-based biomarkers across the spectrum of TBI.

METHODS

A literature search of the PubMed/Medline electronic database was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We excluded systematic reviews and meta-analyses that did not provide novel data. The American College of Cardiology/American Heart Association criteria were used to assess levels of evidence.

RESULTS

An initial 1463 studies were identified. In total, 115 full-text articles reporting on 94 distinct biomarkers met the inclusion criteria. Glasgow Coma Scale scores, computed tomography/magnetic resonance imaging abnormalities, and injury severity scores were the most used clinical diagnostic variables. Glasgow Outcome Scores and 1-, 3-, and 6-month mortality were the most used clinical prognostic variables. Several biomarkers significantly correlated with these variables and had statistically significant different levels in TBI subjects when compared with healthy, orthopedic, and polytrauma controls. The biomarkers also displayed significant variability across mild, moderate, and severe TBI categories, as well as in concussion cases.

CONCLUSIONS

This review summarizes existing high-quality evidence that supports the use of severity-specific biomarkers in the diagnostic and prognostic evaluation of TBI. These data can be used as a launching platform for the validation of upcoming clinical studies.

Incidence and predictors of mortality among patients with head injury admitted to Hawassa University Comprehensive Specialized Hospital, Southern Ethiopia: A retrospective follow-up study

Introduction

Head injury is the leading cause of morbidity and mortality throughout the world, especially in resource-limited countries including Ethiopia. However, little is known about the mortality rate and its predictors among these patients in Ethiopia. Thus, the study aims to assess the incidence rate of mortality and its predictors among patients with head injury admitted at Hawassa University Comprehensive Specialized Hospital.

Methods

Institutional based retrospective follow-up study was conducted among 1220 randomly selected head injury patients admitted from July 2017 to July 2019. Bivariable and multivariable Cox regression models were fitted to identify the predictors of mortality. Proportionality assumption was tested by a global test based on the Schoenfeld residuals test.

Results

The incidence of the mortality rate was 2.26 (95%CI: 1.9–2.6) per 100-person day observation. The independent predictors of time to death were age above 65 years (AHR:3.49, 95%CI:1.63, 7.48), severe TBI (AHR: 8.8, 95%CI:5.13, 15.0), moderate TBI (AHR:3, 95%CI:1.73,5.31), hypotension (AHR:1.72, 95%CI: 1.11,2.66), hypoxia (AHR:1.92, 95%CI: 1.33,2.76), hyperthermia (AHR:1.8, 95%CI: 1.23,2.63) and hypoglycemic (AHR:1.94, 95%CI: 1.34, 2.81) positively associated with mortality, while underwent neurosurgery was negatively associated with mortality (AHR: 0.25, 95% CI: 0.11,0.53).

Conclusion

The incidence of mortality rate among head injury patients was high. Older age, moderate and severe TBI, hypotension and hypoxia at admission, neurosurgical procedure, and the episode of hyperthermia and hypoglycemia during hospitalization were the independent predictors of mortality among head injury patients. Therefore, intervention to reduce earlier deaths should focus on the prevention of secondary brain insults.

Post-craniotomy fever and its associated factors in patients with traumatic brain injury

BACKGROUND

Fever frequently occurs in patients with traumatic brain injury and can cause secondary damage to the brain. Critical care nurses play essential roles in assessing and managing fever in these patients.

AIM

The study aimed to (a) examine the fever causes in and condition of neurosurgical patients with traumatic brain injury in intensive care, (b) identify the factors associated with fever, and (c) determine the effects of fever on hospital stay and prognosis.

STUDY DESIGN

This study is a retrospective observational design.

METHODS

Data were collected through chart reviews of 93 traumatic brain injury patients admitted to a teaching hospital's intensive care unit for postoperative care. Fever was defined as at least one episode of body temperature >38°C.

RESULTS

Of the 93 patients, 76 developed a fever within 1-week post-craniotomy. Of these, 49 were infection-related and 27 were unexplained. Results of logistic regression showed that the preoperative Glasgow coma scale score (ß = -.323; P = .013) and length of intubation (ß = .480; P = .005) were the key predictors of unexplained post-craniotomy fever, and these two variables (ß = -.494; P < .001 and ß = .479; P = .006, respectively) were also the key predictors of infection-related fever.

CONCLUSION

A significant portion of patients developed a fever during the first post-craniotomy week. Patients with a lower pre-craniotomy Glasgow coma scale score and a longer intubation length were at a greater risk for both infection-related fever and unexplained fever. Patients with fever had a bad outcome score.

RELEVANCE TO CLINICAL PRACTICE

Critical care nurses should closely monitor traumatic brain injury patients' body temperatures and employ evidence-based infection prevention and control measures to minimize their infection risks. Respiratory care and intensive care unit Liberation Bundle should be reinforced to liberate these patients from mechanical ventilation and its associated complications.

Factors affecting functional outcomes of traumatic brain injury rehabilitation at a rehabilitation facility in Saudi Arabia

Objectives:

To identify the factors that affect disability after inpatient rehabilitation (IPR) in persons with traumatic brain injury (TBI).

Methods:

This retrospective study identified 140 patients aged ≥16 years who were admitted to the TBI rehabilitation unit at King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia between 2015 and 2017. The collected data included demographic variables, TBI cause, coma duration, time from injury to IPR, LOS, and Functional Independence Measure (FIM) scores at IPR admission and discharge.

Results:

Majority of the patients were young males. The TBI was caused by motor vehicle accidents (MVA) in 95% of patients. The mean coma duration, time from injury to IPR admission, and LOS were 47±38, 264±357, and 75±52 days, respectively. The factors that were found to have an association with FIM change were time from injury to IPR admission (p=0.003, r=-0.250), admission FIM score (p=0.003, r=-0.253), and discharge FIM score (p<0.001, r=0.390). Employed patients had high FIM scores at admission (p=0.029, r=0.184) and discharge (p=0.003, r=0.252).

Conclusion:

Reduction in disability at discharge was positively associated with the severity of disability at admission and negatively with the time duration from injury to IPR admission, indicating a need to reduce time before admittance to an IPR setup. The high incidence of MVA causing TBI in a young male population strongly points to a need for appropriate measures of prevention.

Genetic factors and the risk of drug-resistant epilepsy in young children with epilepsy and neurodevelopment disability: A prospective study and updated meta-analysis

Drug-resistant epilepsy (DRE) affects 7% to 20% of children with epilepsy. Although some risk factors for DRE have been identified, the results have not been consistent. Moreover, data regarding the risk factors for epilepsy and its seizure outcome in the first 2 years of life are limited.We analyzed data for children aged 0 to 2 years with epilepsy and neurodevelopmental disability from January, 2013, through December, 2017. These patients were followed up to compare the risk of DRE in patients with genetic defect (genetic group) with that without genetic defect (nongenetic group). Additionally, we conducted a meta-analysis to identify the pooled prevalence of genetic factors in children with DRE.A total of 96 patients were enrolled. A total of 68 patients were enrolled in the nongenetic group, whereas 28 patients were enrolled in the genetic group. The overall DRE risk in the genetic group was 6.5 times (95% confidence interval [CI], 2.15-19.6; p = 0.03) higher than that in the nongenetic group. Separately, a total of 1308 DRE patients were participated in the meta-analysis. The pooled prevalence of these patients with genetic factors was 22.8% (95% CI 17.4-29.3).The genetic defect plays a crucial role in the development of DRE in younger children with epilepsy and neurodevelopmental disability. The results can serve as a reference for further studies of epilepsy panel design and may also assist in the development of improved treatments and prevention strategies for DRE.

Neurologic Assessment of the Neurocritical Care Patient

Sedation is a ubiquitous practice in ICUs and NCCUs. It has the benefit of reducing cerebral energy demands, but also precludes an accurate neurologic assessment. Because of this, sedation is intermittently stopped for the purposes of a neurologic assessment, which is termed a neurologic wake-up test (NWT). NWTs are considered to be the gold-standard in continued assessment of brain-injured patients under sedation. NWTs also produce an acute stress response that is accompanied by elevations in blood pressure, respiratory rate, heart rate, and ICP. Utilization of cerebral microdialysis and brain tissue oxygen monitoring in small cohorts of brain-injured patients suggests that this is not mirrored by alterations in cerebral metabolism, and seldom affects oxygenation. The hard contraindications for the NWT are preexisting intracranial hypertension, barbiturate treatment, status epilepticus, and hyperthermia. However, hemodynamic instability, sedative use for primary ICP control, and sedative use for severe agitation or respiratory distress are considered significant safety concerns. Despite ubiquitous recommendation, it is not clear if additional clinically relevant information is gleaned through its use, especially with the contemporaneous utilization of multimodality monitoring. Various monitoring modalities provide unique and pertinent information about neurologic function, however, their role in improving patient outcomes and guiding treatment plans has not been fully elucidated. There is a paucity of information pertaining to the optimal frequency of NWTs, and if it differs based on type of injury. Only one concrete recommendation was found in the literature, exemplifying the uncertainty surrounding its utility. The most common sedative used and recommended is propofol because of its rapid onset, short duration, and reduction of cerebral energy requirements. Dexmedetomidine may be employed to facilitate serial NWTs, and should always be used in the non-intubated patient or if propofol infusion syndrome (PRIS) develops. Midazolam is not recommended due to tissue accumulation and residual sedation confounding a reliable NWT. Thus, NWTs are well-tolerated in selected patients and remain recommended as the gold-standard for continued neuromonitoring. Predicated upon one expert panel, they should be performed at least one time per day. Propofol or dexmedetomidine are the main sedative choices, both enabling a rapid awakening and consistent NWT.

An economic evaluation for the use of decompressive craniectomy in the treatment of refractory traumatic intracranial hypertension

Objectives: The management of intracranial hypertension is a primary concern following traumatic brain injury. Data from recent randomized controlled trials have indicated that decompressive craniectomy results in some improved clinical outcomes compared to medical treatment for patients with refractory intracranial hypertension post-traumatic brain injury (TBI). This economic evaluation aims to assess the cost-effectiveness of decompressive craniectomy as a last-tier intervention for refractory intracranial hypertension from the perspective of the National Health Service (NHS).Methods: A Markov model was used to present the results from an international, multicentre, parallel-group, superiority, randomized trial. A cost-utility analysis was then carried out over a 1-year time horizon, measuring benefits in quality adjusted life years (QALYs) and costs in pound sterling.Results: The cost-utility analysis produced an incremental cost-effectiveness ratio (ICER) of £96,155.67 per QALY. This means that for every additional QALY gained by treating patients with decompressive craniectomy, a cost of £96,155.67 is incurred to the NHS.Conclusions: The ICER calculated is above the National Institute for Health and Care Excellence (NICE) threshold of £30,000 per QALY. This indicates that decompressive craniectomy is not a cost-effective first treatment option for refractory intracranial hypertension and maximum medical management is preferable initially.

Decompressive Surgery for Patients with Traumatic Brain Injury

Traumatic brain injury, which is a clinical spectrum, requires a thorough evaluation and strict monitoring for clinical deterioration owing to ongoing secondary injury and raised intracranial pressure. Once the intracranial pressure has been treated with maximal medical therapy, surgical decompression is necessary and must be initiated rapidly. Anesthetic management of surgical decompression must balance reduction of the intracranial pressure, maintenance of cerebral perfusion pressures, avoidance of secondary injuries, and optimization of surgical conditions.

Drug Use in Pediatric Patients Admitted to Rehabilitation For Severe Acquired Brain Injury: Analysis of the Associations With Rehabilitation Outcomes

INTRODUCTION

Patients with severe acquired brain injuries require drug therapies in intensive care for life support and injury treatment. Patients who then access rehabilitation usually maintain their drug treatments long term, with a potential influence on the rehabilitation course. Whereas drug effects have been reported for specific drugs and clinical issues in adults, comprehensive data on pediatric patients with traumatic and non-traumatic injuries are scant.

OBJECTIVES

The aims of this study were to describe the therapeutic classes and groups of drugs prescribed to pediatric inpatients recovering from severe acquired brain injury when they enter rehabilitation; to assess whether clinical variables may determine the use of drug classes; and to assess whether the use of drug classes may be associated with differences in rehabilitation outcomes.

METHODS

We carried out a retrospective chart review, following a previous study on the clinical-epidemiological characteristics of our patients. We collected information on drug therapies present at admittance to rehabilitation and analyzed their distribution according to therapeutic classes and groups. We verified the associations of drug groups with clinical variables (putatively antecedents to drug use) and with rehabilitation outcomes (putatively resultant of drug use and of clinical variables) in regression models. The clinical variables considered were injury etiology, Glasgow Outcome Score (GOS) at admittance to rehabilitation, sex, age at injury, plus two aggregate factors resulting from the previous work, 'neurological dysfunction' regarding the use of devices and 'injury severity' regarding the neurological status. The rehabilitation outcomes used were death after rehabilitation, persistence of a vegetative/minimally conscious state, coma duration, duration of the rehabilitation stay, rehabilitation efficiency (GOS at discharge minus GOS at admittance, divided by the length of rehabilitation stay).

RESULTS

We described the distribution of drug classes and groups among pediatric patients with severe acquired brain injuries. Regarding the associations between drug classes and clinical variables, we found greater use of cardiovascular agents with higher patient age, 'neurological dysfunction' score, and with an etiology of hypoxic brain injury. The use of antithrombotic agents was greater with higher patient age and 'neurological dysfunction' score. Glucocorticoid use was greater with higher GOS at admittance and with several etiologies: brain tumor, infective encephalitis, and autoimmune encephalitis. Regarding drug classes and rehabilitation outcomes, we found that the use of cardiovascular drugs was associated with increased occurrence of death after rehabilitation. The use of antispastic drugs was associated with a more frequent permanence in vegetative/minimally conscious states. The use of antispastic drugs and melatonin was associated with longer coma duration. The use of glucocorticoid drugs was associated with decreased rehabilitation efficiency.

CONCLUSIONS

We provided a description of drug use in pediatric rehabilitation after severe acquired brain injuries, which was lacking in the literature. Prospective studies should verify our associative observations regarding clinical variables, drugs use, and outcomes, to assess causality.

Dispatch of a helicopter emergency medicine service to patients with a sudden, unexplained loss of consciousness of medical origin

Background

Sudden loss of consciousness (LOC) in the prehospital setting in the absence of cardiac arrest and seizure activity may be a challenge from a dispatcher’s perspective: The aetiology is varied, with many causes being transient and mostly self-limiting, whereas other causes are potentially life threatening. In this study we aim to evaluate the dispatch of HEMS to patients with LOC of medical origin, by exploring to which patients with a LOC HEMS is dispatched, which interventions HEMS teams perform in these patients, and whether HEMS interventions can be predicted by patient characteristics.

Methods

We performed retrospective cohort study of all patients with a reported unexplained LOC (e.g. not attributable to a circulatory arrest or seizures) attended by the Air Ambulance Kent, Surrey & Sussex (AAKSS), over a 4-year period (July 2013–December 2017). Primary outcome was defined as the number of HEMS-specific interventions performed in patients with unexplained LOC. Secondary outcome was the relation of clinical- and dispatch criteria with HEMS interventions being performed.

Results

During the study period, 127 patients with unexplained LOC were attended by HEMS. HEMS was dispatched directly to 25.2% of the patients, but mostly (74.8%) on request of the ground ambulance crews. HEMS interventions were performed in 65% of the patients (Prehospital Emergency Anaesthesia 56%, hyperosmolar therapy 21%, antibiotic/antiviral therapy 8%, vasopressor therapy 6%) and HEMS conveyed most patients (77%) to hospital. Acute neurological pathology was a prevalent underlying cause of unexplained LOC: 38% had gross pathology on their CT-scan upon arrival in hospital. Both GCS (r = − 0.60, p < .001) and SBP (r = 0.31, p < .001) were related to HEMS interventions being performed on scene. A GCS < 13 predicted the need for HEMS interventions in our population with a sensitivity of 94.9% and a specificity 75% (AUC 0.85).

Conclusion

HEMS dispatchers and ambulance personnel are able to identify a cohort of patients with unexplained LOC of medical origin who suffer from potentially life threatening (mainly neurological) pathology, in whom HEMS specific intervention are frequently required. Presenting GCS can be used to inform the triage process of patients with LOC at an early stage.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-020-00388-x.

Critical Appraisal of Traumatic Brain Injury and Its Management

Critical appraisal of traumatic brain injury (TBI) management has always been marred with a conflict of differential approaches, with claims and counterclaims of outcomes among the research groups. We performed this study to review the management of TBI from risk factors to outcomes including the comorbidities and final clinical status. In conjunction with the aforesaid stabilization of TBI cases, prophylactic and definitive surgical approaches and other supporting interventions will ultimately decide the final outcomes in the long run. Improvements in the quality of care for patients with severe TBI, with the reduction in mortality, have been demonstrated in high-income areas due to improvements in the health care system and not just in one isolated intervention. In the management of TBI, a fast and high index of suspicion is the key to success, from the initial assessment to the final rehabilitation of the cases, from the victim of risk factors to the victims of situation. The research groups feel that TBI prophylactic measures and primary care mitigation models are as important as definitive care, starting from prehospital care to dedicated care.

High Versus Low Volume Fluid Resuscitation Strategies in a Porcine Model (Sus scrofa) of Combined Thermal and Traumatic Brain Injury

BACKGROUND

Combined burn and traumatic brain injury (TBI) treatment priorities may not align due to opposing fluid resuscitation paradigms used in treating burns and TBI. We developed a porcine model of combined thermal injury/TBI and compared an "aggressive" fluid resuscitation strategy using the Parkland formula and a "restrictive" resuscitation strategy using the modified Brooke formula.

METHODS

Twenty-eight swine were deeply anesthetized and received a 40% total body surface area full-thickness burn injury and TBI. Swine were then randomized to receive restrictive or aggressive resuscitation for 8 h after which time animals were euthanized and necropsy was performed. Volume of brain injury was assessed after analyzing segmental slices of brain tissue.

RESULTS

There were no differences between the restrictive and aggressive resuscitation groups in blood pressure, heart rate, central venous pressure, intra-cranial pressure (ICP), or serum lactate levels after 8 h of resuscitation. Urine output was higher in the aggressive resuscitation group. The restrictive group had a significantly higher serum blood urea nitrogen (BUN) compared with baseline and compared with the aggressive group. There was no significant difference in size of brain injury between groups.

CONCLUSIONS

Both restrictive and aggressive resuscitation demonstrated adequate resuscitation at 8 h postinjury. Increased serum BUN in the restrictive group may be an indicator of early acute kidney injury, despite adequate urine output. Resuscitation strategy did not appear to affect ICP or the size of brain injury.

Regional Variations in Rehabilitation Outcomes of Adult Patients With Traumatic Brain Injury: A Uniform Data System for Medical Rehabilitation Investigation

OBJECTIVES

To examine regional differences in rehabilitation outcomes among adult patients with moderate-to-severe traumatic brain injury (TBI) who received care at an inpatient rehabilitation facility (IRF).

DESIGN

We conducted a secondary analysis of a large, multi-center dataset from the Uniform Data System for Medical Rehabilitation.

SETTING

More than 70% of all IRFs in the United States.

PARTICIPANTS

Adult TBI patients (N=175,358) aged 18 years or older who were admitted and discharged from an IRF in the United States between 2004 and 2014. Qualifying etiology included traumatic brain dysfunction Impairment Group codes 02.21 (traumatic, open injury) and 02.22 (traumatic, closed injury).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Discharge functional status (total, cognitive, motor), length of stay, and discharge to home.

RESULTS

Patient and clinical characteristics varied significantly by geographic location, as did median functional status, length of stay, and percentage of patients discharged home. The region where IRF care was received, race and ethnicity, age, occurrence of 1 or more falls during the IRF stay, case mix group, and insurance status were associated with discharge functional status, length of stay, and discharge to home.

CONCLUSIONS

Our findings provide evidence of geographic differences in outcomes and potential disparities in care of TBI patients who received IRF care. More research is needed to identify TBI patients at risk for poor discharge outcomes to inform development and testing of interventions to reduce disparities in outcomes for these patients.