Diffuse Axonal Injury in Patients With Head Injuries: An Epidemiologic and Prognosis Study of 124 Cases

Hyperglycemia disrupted the integrity of the blood-brain barrier following diffuse axonal injury through the sEH/NF-κB pathway

OBJECTIVES

We aimed to investigate the role of soluble epoxide hydrolase for hyperglycemia induced-disruption of blood-brain barrier (BBB) integrity after diffuse axonal injury (DAI).

METHODS

Rat DAI hyperglycemia model was established by a lateral head rotation device and intraperitoneal injection of 50% glucose. Glial fibrillary acidic protein, ionized calcium-binding adapter molecule-1, β-amyloid precursor protein, neurofilament light chain, and neurofilament heavy chain was detected by immunohistochemistry. Cell apoptosis was examined by terminal deoxynucleotidyl transferase nick-end labeling (TUNEL) assay. The permeability of blood-brain barrier (BBB) was assessed by expression of tight junction proteins, leakage of Evans blue and brain water content. The soluble epoxide hydrolase (sEH) pathway was inhibited by 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU) and the nuclear transcription factor kappa B (NF-κB) pathway was inhibited by pyrrolidine dithiocarbamate and activated by phorbol-12-myristate-13-acetate in vivo and/or vitro, respectively. The inflammatory factors were detected by enzyme-linked immunosorbent assay.

RESULTS

Hyperglycemia could exacerbate axonal injury, aggravate cell apoptosis and glial activation, worsen the loss of BBB integrity, increase the release of inflammatory factors, and upregulate the expression of sEH and NF-κB. Inhibition of sEH could reverse all these damages and protect BBB integrity by upregulating the expression of tight junction proteins and downregulating the levels of inflammatory factors in vivo and vitro, while the agonist of NF-κB pathway abrogated the protective effects of TPPU on BBB integrity in vitro.

CONCLUSIONS

sEH was involved in mediating axonal injury induced by hyperglycemia after DAI by disrupting BBB integrity through inducing inflammation via the NF-κB pathway.

Unusual Presentation of Diffuse Axonal Injury: A Case Report

Diffuse axonal injury (DAI) is the microscopic axonal injury in the brain's neural pathways, corpus callosum, and brainstem, which has been linked to a major increase in morbidity and mortality. Patients present acutely with no lucid interval, abnormal pupil response, and decerebrate or decorticate posture. In this case report, we report on an 11-year-old girl who was agitated, crying, vomiting, had one episode of seizure, and had poor communication as a result of a high-risk mechanism side-impact motor vehicle collision (MVC).

Paroxysmal Sympathetic Hyperactivity in Adult Patients with Brain Injury: A Systematic Review and Meta-Analysis

BACKGROUND

Paroxysmal sympathetic hyperactivity (PSH) is a syndrome of excessive sympathetic activity, mainly occurring in severe traumatic brain injury. However, few studies have reported the frequency of PSH and its related risk factors in adult patients with brain injury.

METHODS

We performed this systematic review and meta-analysis to estimate the combined incidence of PSH and the associated risk factors in adult patients with brain injury. This study was registered with the PROSPERO international prospective register of systematic reviews (https://www.crd.york. ac.uk/PROSPERO/Identifier: CRD 42021260493), and a systematic search was conducted of the scientific databases Embase, PubMed, Web of Science, Cochrane Library, and Google Scholar. All identified observational studies regarding the incidence and risk factors of PSH in adult patients with brain injury were included. Two authors extracted data independently; data were analyzed by STATA version 16.

RESULTS

The search yielded 9 studies involving 1643 adult patients. PSH was detected in 438 patients. The combined incidence of PSH in adult patients with brain injury was 27.4% (95% confidence interval [CI], 0.190-0.358). The risk factors include patients' age (SMD = -0.592; I² = 77.5%; 95% CI, -1.027 to -0.156; P = 0.008), traffic accident (odds ratio [OR], 1.783; I² =18.0%; 95% CI, 1.128-2.820; P = 0.013), admission Glasgow Coma Scale score (SMD = -1.097; I² =28.3%; 95% CI, -1.500 to -0.693; P = 0.000), hydrocephalus (OR, 3.936; I² =67.9%; 95% CI, 1.144-13.540; P = 0.030), and diffuse axonal injury (OR, 4.747; I² =71.1%; 95% CI, 1.221-18.463; P = 0.025) and were significantly associated with the presence of PSH after brain injury.

CONCLUSIONS

PSH occurs in nearly a quarter of adult patients with brain injury. Patient's age, traffic accident, admission Glasgow Coma Scale score, hydrocephalus, and diffuse axonal injury were risk factors for PSH in adult patients with brain injury. These findings may contribute to novel strategies for early diagnosis and interventions that aid in the rehabilitation of patients with brain injury.

The ratio of serum neuron-specific enolase level to admission glasgow coma scale score is associated with diffuse axonal injury in patients with moderate to severe traumatic brain injury

Background

Moderate to severe traumatic brain injury (TBI) is frequently accompanied by diffuse axonal injury (DAI). Considering the low sensitivity of computed tomography (CT) examination for microbleeds and axonal damage, identification of DAI is difficult using conventional diagnostic methods in the acute phase. Neuron-specific enolase (NSE) has been demonstrated to be increased in serum following various types of TBI and is already clinically/commercially available. We conjecture that serum NSE level to admission GCS score ratio (NGR) may be a useful indicator for the early diagnosis of DAI.

Methods

This study included 115 patients with moderate-to-severe TBI who underwent NSE measurements within 6 h after injury and brain magnetic resonance imaging (MRI) within 30 days. The positive and negative DAI groups were divided according to MRI findings.

Results

Among the 115 patients, 49 (42.6%) were classified into the DAI group and 66 (57.4%) patients into the non-DAI group by clinical MRI. The NGR of patients without DAI was found to be significantly lower than those of patients with DAI (p < 0.0001). NGR presented the largest Pearson r value (r = 0.755, 95% CI 0.664–0.824, p < 0.0001) and high diagnostic accuracy for DAI [area under the curve (AUC) = 0.9493; sensitivity, 90.91%; and specificity, 85.71%]. Patients with TBI presenting with higher NGR were more likely to suffer an unfavorable neurological outcome [6-month extended Glasgow Outcome Scale (GOSE) 1–4].

Conclusions

The NGR on admission could serve as an independent predictor of DAI with moderate-to-severe TBI.

Pediatric traumatic brain injury: a new relation between outcome and neutrophil-to-lymphocite ratio

Leading causes of death in industrialized countries are traumatic injuries and acquired disability, and entry to the emergency department in childhood. TBI (traumatic brain injury) may involve the onset of both primary lesions and a complex immune response (sterile immune reaction to brain injury), which, in addition to neuro-protective effects, can mediate secondary neurological injury. The neutrophil-to-lymphocyte ratio (NLR), as a circulating inflammatory marker, has been related to outcomes in adult patients with non-neurologic diseases (such as gut tumours) or neurologic diseases (such as stroke or brain tumours), and to the prognosis of traumatic brain injury in adolescents and adults. However, the potential role of NLR in predicting outcomes in paediatric head trauma is not clearly defined. The aim of this retrospective observational study is to evaluate the association between clinical features predictive of intracranial and extracranial lesions in TBI and NLR and to establish whether an elevation of NLR is indirectly associated with adverse outcomes in pediatric patients with TBI. We analysed a sample of 219 pediatric patients, between 2-18 years old, after a TBI, and evaluated if differences in NLR were associated with neurological signs or positive CT in pediatric patients. We then compared the NLR values between healthy subjects and patients with TBI. (www.actabiomedica.it)

Can Ultrasound-Guided Xenon Delivery Provide Neuroprotection in Traumatic Brain Injury?

Traumatic brain injury (TBI) is associated with high mortality and morbidity in children and adults. Unfortunately, there is no effective management for TBI in the acute setting. Rodent studies have shown that xenon, a well-known anesthetic gas, can be neuroprotective when administered post-TBI. Gas inhalation therapy, however, the approach typically used for administering xenon, is expensive, inconvenient, and fraught with systemic side effects. Therapeutic delivery to the brain is minimal, with much of the inhaled gas cleared by the lungs. To bridge major gaps in clinical care and enhance cerebral delivery of xenon, this study introduces a novel xenon delivery technique, utilizing microbubbles, in which a high impulse ultrasound signal is used for targeted cerebral release of xenon. Briefly, an ultrasound pulse is applied along the carotid artery at the level of the neck on intravenous injection of xenon microbubbles (XeMBs) resulting in release of xenon from microbubbles into the brain. This delivery technique employs a hand-held, portable ultrasound system that could be adopted in resource-limited environments. Using a high-fidelity porcine model, this study demonstrates the neuroprotective efficacy of xenon microbubbles in TBI for the first time.

Prognosticating outcome using magnetic resonance imaging in patients with moderate to severe traumatic brain injury: a machine learning approach

INTRODUCTION

Over the last decade advancements in computer processing have enabled the application of machine learning (ML) to complex medical problems. Convolutional neural networks (CNN), a type of ML, have been used to interrogate medical images for variety of purposes. In this study, we aimed to investigate the potential application of CNN in prognosticating patients with traumatic brain injury (TBI).

METHODS

Patients with moderate to severe TBI and evidence of diffuse axonal injury (DAI) were selected retrospectively. A CNN model was developed using a training subgroup and a holdout subgroup was used as a testing dataset. We reported the model characteristics including area under the receiver operating characteristic curve (AUC).

RESULTS

We included a total of 38 patient, of which we generated 725 MRI sections. We developed a CNN model based on a modified AlexNet architecture that interpreted the brain stem injury to generate outcome predictions. The model was able to predict GOS outcomes with a specificity of 0.43 and a sensitivity of 0.997. It showed an AUC of 0.917.

CONCLUSION

The utilization of machine learning MRI analysis for prognosticating patients with TBI is a valued method that require further investigation. This will require multicentre collaboration to generate large datasets.

Diffuse Axonal Injury: Clinical Prognostic Factors, Molecular Experimental Models and the Impact of the Trauma Related Oxidative Stress. An Extensive Review Concerning Milestones and Advances

Traumatic brain injury (TBI) is a condition burdened by an extremely high rate of morbidity and mortality and can result in an overall disability rate as high as 50% in affected individuals. Therefore, the importance of identifying clinical prognostic factors for diffuse axonal injury (DAI) in (TBI) is commonly recognized as critical. The aim of the present review paper is to evaluate the most recent contributions from the relevant literature in order to understand how each single prognostic factor determinates the severity of the clinical syndrome associated with DAI. The main clinical factors with an important impact on prognosis in case of DAI are glycemia, early GCS, the peripheral oxygen saturation, blood pressure, and time to recover consciousness. In addition, the severity of the lesion, classified on the ground of the cerebral anatomical structures involved after the trauma, has a strong correlation with survival after DAI. In conclusion, modern findings concerning the role of reactive oxygen species (ROS) and oxidative stress in DAI suggest that biomarkers such as GFAP, pNF-H, NF-L, microtubule associated protein tau, Aβ42, S-100β, NSE, AQP4, Drp-1, and NCX represent a possible critical target for future pharmaceutical treatments to prevent the damages caused by DAI.

Outcome of diffuse axonal injury in moderate and severe traumatic brain injury

Background:

Diffuse axonal injury (DAI) is a common presentation in neurotrauma. Prognosis is variable but can be dependent on the initial presentation of the patient. In our study, we evaluated the outcome of diffuse axonal injury.

Methods:

This study was conducted at a tertiary care center from September 2018 to December 2019 and included 133 adult patients with moderate or severe head injury (GCS ≤ 12) diagnosed to have the DAI on the basis of MRI. At 3 months, the result was assessed using the Extended Glasgow Outcome Scale (GOS-E).

Results:

There were a total of 97 (72.9%) males and 36 (27.1%) females with an average age of 32.4 ± 10 years with a mean GCS of 9 at admission. The most common mode of head trauma was road traffic accidents (RTAs) in 51.9% of patients followed by fall from height in 27.1%. Most patients were admitted with moderate traumatic brain injury (64.7%) and suffered Grade I diffuse axonal injury (41.4%). The average hospital stay was 9 days but majority of patients stayed in hospital for ≤ 11 days. At 3 months, mortality rate was 25.6% and satisfactory outcome observed in 48.1% of patients. The highest mortality was observed in the Grade III DAI.

Conclusion:

We conclude that the severity of the traumatic head injury and the grade of the DAI impact the outcome. Survivors require long-term hospitalization and rehabilitation to improve their chances of recovery.

Diffuse Axonal Injury Grade on Early MRI is Associated with Worse Outcome in Children with Moderate-Severe Traumatic Brain Injury

Background

Traumatic brain injury (TBI) is the leading cause of death and disability in children, but effective tools for predicting outcome remain elusive. Although many pediatric patients receive early magnetic resonance imaging (MRI), data on its utility in prognostication are lacking. Diffuse axonal injury (DAI) is a hallmark of TBI detected on early MRI and was shown previously to improve prognostication in adult patients with TBI. In this exploratory study, we investigated whether DAI grade correlates with functional outcome and improves prognostic accuracy when combined with core clinical variables and computed tomography (CT) biomarkers in pediatric patients with moderate-severe TBI (msTBI).

Methods

Pediatric patients (≤ 19 years) who were admitted to two regional level one trauma centers with a diagnosis of msTBI (Glasgow Coma Scale [GCS] score < 13) between 2011 and 2019 were identified through retrospective chart review. Patients who underwent brain MRI within 30 days of injury and had documented clinical follow-up after discharge were included. Age, pupil reactivity, and initial motor GCS score were collected as part of the International Mission for Prognosis and Analysis of Clinical Trials in TBI (IMPACT) model. Imaging was reviewed to calculate the Rotterdam score (CT) and DAI grade (MRI) and to evaluate for presence of hypoxic-ischemic injury (MRI). The primary outcome measure was the Pediatric Cerebral Performance Category Scale (PCPCS) score at 6 months after TBI, with favorable outcome defined as PCPCS scores 1–3 and unfavorable outcome defined as PCPCS scores 4–6. The secondary outcome measure was discharge disposition to home versus to an inpatient rehabilitation facility.

Result

Of 55 patients included in the study, 45 (82%) had severe TBI. The most common mechanism of injury was motor vehicle collision (71%). Initial head CT scans showed acute hemorrhage in 84% of patients. MRI was acquired a median of 5 days after injury, and hemorrhagic DAI lesions were detected in 87% of patients. Each 1-point increase in DAI grade increased the odds of unfavorable functional outcome by 2.4-fold. When controlling for core IMPACT clinical variables, neither the DAI grade nor the Rotterdam score was independently correlated with outcome and neither significantly improved outcome prediction over the IMPACT model alone.

Conclusions

A higher DAI grade on early MRI is associated with worse 6-month functional outcome and with discharge to inpatient rehabilitation in children with acute msTBI in a univariate analysis but does not independently correlate with outcome when controlling for the GCS score. Addition of the DAI grade to the core IMPACT model does not significantly improve prediction of poor neurological outcome. Further study is needed to elucidate the utility of early MRI in children with msTBI.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-021-01336-8.

Neurobiology of traumatic brain injury

Traumatic brain injury (TBI) involves structural damage to the brain regions causing death or disability in patients with lifelong sufferings. Accidental injuries to the brain, besides structural damage, if any, cause activation of various deleterious pathways leading to subsequent neuronal death and permanent dysfunction. However, immediate medical management/treatments could reduce the chances of disability and suffering to the patients. The objective of the current review is to review triggered molecular pathways following TBI and discuss possible targets that could restore brain functions. Understanding the pathologic process is always useful to device novel treatment strategies and may rescue the patient with TBI from death or associated co-morbidities. The current review significantly contributes to improve our understanding about the molecular pathways and neuronal death following TBI and helps us to provide possible targets that could be useful in the management/treatment of TBI.

Contraindications to the Initiation of Veno-Venous ECMO for Severe Acute Respiratory Failure in Adults: A Systematic Review and Practical Approach Based on the Current Literature

(1) Background: Extracorporeal membrane oxygenation (ECMO) is increasingly used for acute respiratory failure with few absolute but many relative contraindications. The provider in charge often has a difficult time weighing indications and contraindications to anticipate if the patient will benefit from this treatment, a decision that often decides life and death for the patient. To assist in this process in coming to a good evidence-based decision, we reviewed the available literature. (2) Methods: We performed a systematic review through a literature search of the MEDLINE database of former and current absolute and relative contraindications to the initiation of ECMO treatment. (3) Results: The following relative and absolute contraindications were identified in the literature: absolute-refusal of the use of extracorporeal techniques by the patient, advanced stage of cancer, fatal intracerebral hemorrhage/cerebral herniation/intractable intracranial hypertension, irreversible destruction of the lung parenchyma without the possibility of transplantation, and contraindications to lung transplantation; relative-advanced age, immunosuppressed patients/pharmacological immunosuppression, injurious ventilator settings > 7 days, right-heart failure, hematologic malignancies, especially bone marrow transplantation and graft-versus-host disease, SAPS II score ≥ 60 points, SOFA score > 12 points, PRESERVE score ≥ 5 points, RESP score ≤ -2 points, PRESET score ≥ 6 points, and "do not attempt resuscitation" order (DN(A)R status). (4) Conclusions: We provide a simple-to-follow algorithm that incorporates absolute and relative contraindications to the initiation of ECMO treatment. This algorithm attempts to weigh pros and cons regarding the benefit for an individual patient and hopefully assists caregivers to make better, informed decisions.

Organic features of autonomic dysregulation in paediatric brain injury - Clinical and research implications for the management of patients with Rett syndrome

Rett Syndrome (RTT) is a complex neurodevelopmental disorder with autonomic nervous system dysfunction. The understanding of this autonomic dysregulation remains incomplete and treatment recommendations are lacking. By searching literature regarding childhood brain injury, we wanted to see whether understanding autonomic dysregulation following childhood brain injury as a prototype can help us better understand the autonomic dysregulation in RTT. Thirty-one (31) articles were identified and following thematic analysis the three main themes that emerged were (A) Recognition of Autonomic Dysregulation, (B) Possible Mechanisms & Assessment of Autonomic Dysregulation and (C) Treatment of Autonomic Dysregulation. We conclude that in patients with RTT (I) anatomically, thalamic and hypothalamic function should be explored, (II) sensory issues and medication induced side effects that can worsen autonomic function should be considered, and (III) diaphoresis and dystonia ought to be better managed. Our synthesis of data from autonomic dysregulation in paediatric brain injury has led to increased knowledge and a better understanding of its underpinnings, leading to the development of application protocols in children with RTT.

Early computed tomography for acute post-traumatic diffuse axonal injury: a systematic review

Purpose

Diffuse axonal injury (DAI) is the rupture of multiple axons due to acceleration and deceleration forces during a closed head injury. Most traumatic brain injuries (TBI) have some degree of DAI, especially severe TBI. Computed tomography (CT) remains the first imaging test performed in the acute phase of TBI, but has low sensitivity for detecting DAI, since DAI is a cellular lesion. The aim of this study is to search in the literature for CT signs, in the first 24 h after TBI, that may help to differentiate patients in groups with a better versus worst prognosis.

Methods

We searched for primary scientific articles in the PubMed database, in English, indexed since January 1st, 2000.

Results

Five articles were selected for review. In the DAI group, traffic accidents accounted 70% of the cases, 79% were male, and the mean age was 41 years. There was an association between DAI and intraventricular hemorrhage (IVH) and traumatic subarachnoid hemorrhage (tSAH); an association between the IVH grade and number of corpus callosum lesions; and an association between blood in the interpeduncular cisterns (IPC) and brainstem lesions.

Conclusion

In closed TBI with no tSAH, severe DAI is unlikely. Similarly, in the absence of IVH, any DAI is unlikely. If there is IVH, patients generally are clinically worse; and the more ventricles affected, the worse the prognosis.

Serum levels of tau protein increase according to the severity of the injury in DAI rat model

Traumatic brain injury (TBI) in the form of diffuse axonal injury (DAI) is difficult to diagnose in the early phase of the injury. Early diagnosis of DAI may provide opportunity for developing treatment and management strategies. Tau protein has been demonstrated to increase in the early phase of TBI with high diagnostic accuracy in patients with DAI. We tested the biological plausibility of tau protein using a rat DAI model by evaluating the association between serum tau levels and the severity of brain injury. DAI was induced in animals using the Marmarou model. After a survival of 60 minutes, rats were anesthetized and sacrificed after obtaining blood samples (5ml) from the heart. Eighteen rats were employed in the present study and were randomly subjected to sham-operated control (n=4), mild DAI (n=7), and severe DAI (n=7). Of seven severe DAI rats, two rats that had focal injury caused by skull fracture were excluded in the measurement of tau protein level. The serum levels of tau protein in the rat DAI model were found to increase significantly and consistently according to the severity of the injury. Rats with DAI showed significantly higher serum levels of tau protein compared to sham rats; the severe DAI rats had higher levels of tau than moderate DAI and sham rats (sham vs. mild,  P=0.02; mild vs. severe,  P=0.02). In conclusion, serum tau protein levels may be useful as a biomarker for diagnosing and estimating the severity of DAI in the early phase.

Fractal dimension brain morphometry: a novel approach to quantify white matter in traumatic brain injury

Traumatic brain injury (TBI) is the main cause of disability in people younger than 35 in the United States. The mechanisms of TBI are complex resulting in both focal and diffuse brain damage. Fractal dimension (FD) is a measure that can characterize morphometric complexity and variability of brain structure especially white matter (WM) structure and may provide novel insights into the injuries evident following TBI. FD-based brain morphometry may provide information on WM structural changes after TBI that is more sensitive to subtle structural changes post injury compared to conventional MRI measurements. Anatomical and diffusion tensor imaging (DTI) data were obtained using a 3 T MRI scanner in subjects with moderate to severe TBI and in healthy controls (HC). Whole brain WM volume, grey matter volume, cortical thickness, cortical area, FD and DTI metrics were evaluated globally and for the left and right hemispheres separately. A neuropsychological test battery sensitive to cognitive impairment associated with traumatic brain injury was performed. TBI group showed lower structural complexity (FD) bilaterally (p < 0.05). No significant difference in either grey matter volume, cortical thickness or cortical area was observed in any of the brain regions between TBI and healthy controls. No significant differences in whole brain WM volume or DTI metrics between TBI and HC groups were observed. Behavioral data analysis revealed that WM FD accounted for a significant amount of variance in executive functioning and processing speed beyond demographic and DTI variables. FD therefore, may serve as a sensitive marker of injury and may play a role in outcome prediction in TBI.

Near-infrared spectroscopy monitoring in a pre-hospital trauma patient cohort: An analysis of successful signal collection

BACKGROUND

Noninvasive monitoring of cerebral physiology could potentially guide pre-hospital management of patients with traumatic injuries. Near-infrared spectroscopy (NIRS) is one such modality but the consistency of monitoring performance remains unclear. This study assessed the proportion of successful signal collection during pre-hospital care.

METHODS

As part of a prospective observational study, an independent study observer placed three sensors for a Nonin 7610 NIRS device; two on the forehead and one on the forearm. NIRS records were analysed for time of adequate monitoring signal in each sensor (>70% of total pre-hospital time). We also compared pre-hospital scene and transport times for patients with or without NIRS monitoring.

RESULTS

Sixty-three patients with monitoring sensors applied were compared to 255 patients where no study observer was on board and 97 without NIRS monitoring for various reasons within the same time period. The proportion of pre-hospital time with successful monitoring (>70%) was 71.4% (45 of 63) for all three sensors, with at least two sensors functional in 90.4% (57 of 63). The median (interquartile range) scene time was 19 (11-23) minutes in patients with NIRS monitoring compared to 18 (11-27) minutes without NIRS monitoring (P = .570). There was no difference in the median (interquartile range) total pre-hospital time between patients with or without monitoring sensors (72 [59-89] versus 72 [59-80] minutes; P = .605).

CONCLUSIONS

In this pre-hospital observational feasibility study with dedicated personnel an acceptable proportion of measurement time was achieved in over 90% of monitored subjects. Addition of NIRS monitoring did not alter pre-hospital scene or transport times in this research setting.

Brainstem Diffuse Axonal Injury and Consciousness

Background

Severe traumatic brain injuries (TBI), commonly due to motor vehicle accidents may cause death and long-term disability especially when the acceleration-deceleration force on the brain is massive. This may cause shearing of the axonal connections within the cerebral cortex and brainstem in a process referred to as diffuse axonal injury (DAI). Extensive DAI has been postulated to be a poor prognostic indicator for neurological recovery. In our institution, several patients with Grade 3 DAI were observed to recover and achieve neurological outcomes greater than expected given the presence of brainstem injury.

Methods

MRI studies from 100 patients admitted to a large tertiary trauma center for TBI were retrospectively analyzed by two fellowship-trained neuroradiologists. The size of DAI lesions, location of injury within the brainstem, and the number of discrete DAI lesions were measured and recorded. Glasgow Coma Scale (GCS) on arrival and at discharge was noted, as well as the presence of other neurological injuries.

Results

Of 20 patients initially noted to have DAI with lesions of the brainstem, eight of them were discharged with Glasgow Coma Scale (GCS) of 14-15. The 12 patients discharged with reduced consciousness (average GC 7.1) demonstrated a greater number of larger lesions, with a predilection for the dorsal pons.

Conclusion

These results suggest that large, numerous pontine lesions may indicate worse neurological outcomes in patients with these findings.

Prognosis of diffuse axonal injury with traumatic brain injury

BACKGROUND

Determine the prognostic impact of magnetic resonance imaging (MRI)-defined diffuse axonal injury (DAI) after traumatic brain injury (TBI) on functional outcomes, quality of life, and 3-year mortality.

METHODS

This retrospective single center cohort included adult trauma patients (age > 17 years) admitted from 2006 to 2012 with TBI. Inclusion criteria were positive head computed tomography with brain MRI within 2 weeks of admission. Exclusion criteria included penetrating TBI or prior neurologic condition. Separate ordinal logistic models assessed DAI's prognostic value for the following scores: (1) hospital-discharge Functional Independence Measure, (2) long-term Glasgow Outcome Scale-Extended, and (3) long-term Quality of Life after Brain Injury-Overall Scale. Cox proportional hazards modeling assessed DAI's prognostic value for 3-year survival. Covariates included age, sex, race, insurance status, Injury Severity Score, admission Glasgow Coma Scale Score, Marshall Head computed tomography Class, clinical DAI on MRI (Y/N), research-level anatomic DAI Grades I-III (I, cortical; II, corpus callosum; III, brainstem), ventilator days, time to follow commands, and time to long-term follow-up (for logistic models).

RESULTS

Eligibility criteria was met by 311 patients, who had a median age of 40 years (interquartile range [IQR], 23-57 years), Injury Severity Score of 29 (IQR, 22-38), intensive care unit stay of 6 days (IQR, 2-11 days), and follow-up of 5 years (IQR, 3-6 years). Clinical DAI was present on 47% of MRIs. Among 300 readable MRIs, 56% of MRIs had anatomic DAI (25% Grade I, 18% Grade II, 13% Grade III). On regression, only clinical (not anatomic) DAI was predictive of a lower Functional Independence Measure score (odds ratio, 2.5; 95% confidence interval, 1.28-4.76], p = 0.007). Neither clinical nor anatomic DAI were related to survival, Glasgow Outcome Scale-Extended, or Quality of Life after Brain Injury-Overall Scale scores.

CONCLUSION

In this longitudinal cohort, clinical evidence of DAI on MRI may only be useful for predicting short-term in-hospital functional outcome. Given no association of DAI and long-term TBI outcomes, providers should be cautious in attributing DAI to future neurologic function, quality of life, and/or survival.

LEVEL OF EVIDENCE

Epidemiological, level III; Therapeutic, level IV.

Tau protein as a diagnostic marker for diffuse axonal injury

Background

Diffuse axonal injury (DAI) is difficult to identify in the early phase of traumatic brain injury (TBI) using common diagnostic methods. Tau protein is localized specifically in nerve axons. We hypothesized that serum level of tau can be a useful biomarker to diagnose DAI in the early phase of TBI.

Methods & results

We measured serum tau levels in 40 TBI patients who were suspected of DAI within 6 hours after TBI to evaluate the accuracy of the tau level as a diagnostic marker for DAI. Diagnosis of DAI was confirmed according to magnetic resonance imaging (MRI) findings. The serum tau level in the DAI group (n = 13) was significantly higher than that in the non-DAI group (n = 27) (DAI vs. non-DAI, 25.3 [0 to 99.1] pg/mL vs. 0 [0 to 44.4] pg/mL, P = 0.03)). A receiver-operating characteristic curve to evaluate the diagnostic ability of serum tau level within 6 hours for DAI showed an area under the curve of 0.690 with 74.1% for sensitivity and 69.2% for specificity. Serum tau level was not significantly higher in unfavorable outcome group (Glasgow Outcome scale [GOS] score = 1–3 at hospital discharge) compared with favorable outcome group (GOS score = 4–5) (P = 0.19).

Conclusions

Tau protein may be a useful biomarker for diagnosis of DAI in the early phase of TBI.

"Don't lose hope early": Hemorrhagic diffuse axonal injury on head computed tomography is not associated with poor outcome in moderate to severe traumatic brain injury patients

BACKGROUND

Diffuse axonal injury (DAI) on magnetic resonance imaging has been associated with poor functional outcome after moderate-severe traumatic brain injury (msTBI). Yet, DAI assessment with highly sensitive magnetic resonance imaging techniques is unfeasible in the acute trauma setting, and computed tomography (CT) remains the key diagnostic modality despite its lower sensitivity. We sought to determine whether CT-defined hemorrhagic DAI (hDAI) is associated with discharge and favorable 3- and 12-month functional outcome (Glasgow Coma Scale score ≥4) after msTBI.

METHODS

We analyzed 361 msTBI patients from the single-center longitudinal Outcome Prognostication in Traumatic Brain Injury study collected over 6 years (November 2009 to November 2015) with prospective outcome assessments at 3 months and 12 months. Patients with microhemorrhages on CT were designated "CT-hDAI-positive" and those without as "CT-hDAI-negative." For secondary analyses "CT-hDAI-positive" was stratified into two phenotypes according to presence ("associated") versus absence ("predominant") of concomitant large acute traumatic lesions to determine whether presence versus absence of additional focal mass lesions portends a different prognosis.

RESULTS

Seventy (19%) patients were CT-hDAI-positive (n = 36 predominant; n = 34 associated hDAI). In univariate analyses, CT-hDAI-positive status was associated with discharge survival (p = 0.004) and favorable outcome at 3 months (p = 0.003) and 12 months (p = 0.005). After multivariable adjustment, CT-hDAI positivity was no longer associated with discharge survival and functional outcome (all ps > 0.05). Stratified by hDAI phenotype, predominant hDAI patients had worse trauma severity, longer intensive care unit stays, and more systemic medical complications. Predominant hDAI, but not associated hDAI, was an independent predictor of discharge survival (adjusted odds ratio, 24.7; 95% confidence interval [CI], 3.2-192.6; p = 0.002) and favorable 12-month outcome (adjusted odds ratio, 4.7; 95% CI, 1.5-15.2; p = 0.01). Sensitivity analyses using Cox regression confirmed this finding for 1-year survival (adjusted hazard ratio, 5.6; 95% CI, 1.3-23; p = 0.048).

CONCLUSION

The CT-defined hDAI was not an independent predictor of unfavorable short- and long-term outcomes and should not be used for acute prognostication in msTBI patients. Predominant hDAI patients had good clinical outcomes when supported to intensive care unit discharge and beyond.

LEVEL OF EVIDENCE

Prognostic study, level III.

Diffuse axonal injury (DAI) in moderate to severe head injured patients: Pure DAI vs. non-pure DAI

OBJECTIVE

Diffuse axonal injury (DAI) is known to be associated with poor outcome. DAI often associates with other intracranial injuries but their distinct features have not been established. In this retrospective cohort study, we compared clinical outcomes between pure and non-pure DAI patients.

PATIENTS AND METHODS

Total of 1047 traumatic brain injury (TBI) patients visited our institute between 2011 and 2017. Age ranged between 15-85 years old and Glasgow coma scale (GCS) score less than 13 were included. DAI was diagnosed in 45 patients using CT and MRI and their clinical features and outcomes were compared depending on their associated cranial injury; 20 patients without evidence of associated injury (Pure DAI group) and other 25 patients with associated injury (Non-pure DAI group). DAI stage was adopted using Gentry, L.R.

CLASSIFICATION

Glasgow outcome scale (GOS) was measured at least 6 months after trauma to evaluate their functional outcome.

RESULTS

The mean age and follow-up period were 45.36 years and 15.09 months, respectively. There were no significant differences between pure and non-pure DAI groups regarding demographic data and clinical findings on their admission. Logistic regression model was used to examine the association between GOS and clinical factors. In this analysis, pure DAI was no significantly different to non-pure DAI (p = 0.607). However, DAI Stage, transfusion, and hypotension on admission were strongly related to poor outcome. Stage III showed sevenfold higher risk when compared to Stage I (p = 0.010). The risk was also high when Stage III was compare to Stage I and II (p = 0.002). Interestingly, no significant difference was observed between Stage I and II (p = 0.847).

CONCLUSIONS

Unfavorable outcome was observed in 14 patients (31.11%) which was lower than we expected. Interestingly, non-pure DAI was no worse than pure DAI on their functional outcome. However, DAI Stage III was independently associated with poor outcome when compared to Stage I or I and II. Finally, we concluded that Stage II is clinically more related to Stage I, rather than Stage III.

Diffuse axonal injury after traumatic brain injury is a prognostic factor for functional outcome: a systematic review and meta-analysis

OBJECTIVE

To determine the prognosis of adult patients with traumatic brain injury (TBI) and diffuse axonal injury (DAI).

METHODS

Online search (PubMed, Embase and Ovid Science Direct) of articles providing information about outcome in (1) patients with DAI in general, (2) DAI vs. non-DAI, (3) related to magnetic resonance imaging (MRI) classification and (4) related to lesion location/load. A reference check and quality assessment were performed.

RESULTS

A total of 32 articles were included. TBI patients with DAI had a favourable outcome in 62%. The risk of unfavourable outcome in TBI with DAI was three times higher than in TBI without DAI. Odds ratio (OR) for unfavourable outcome was 2.9 per increase of DAI grade on MRI. Lesions located in the corpus callosum were associated with an unfavourable outcome. Other specific lesion locations and lesions count showed inconsistent results regarding outcome. Lesion volume was predictive for outcome only on apparent diffusion coefficient and fluid attenuation inversion recovery MRI sequences.

CONCLUSIONS

Presence of DAI on MRI in patients with TBI results in a higher chance of unfavourable outcome. With MRI grading, OR for unfavourable outcome increases threefold with every grade. Lesions in the corpus callosum in particular are associated with an unfavourable outcome.

Clinical characteristics and prognosis of traumatic head injury following road traffic accidents admitted in ICU "analysis of 694 cases"

BACKGROUND

The aim of the present study is to analyze the clinical and epidemiological characteristics of Traumatic Brain Injury (TBI) following Road Traffic Accidents (RTAs). Moreover, we aim to evaluate the outcome of the TBI victims referred to our medico-surgical Intensive Care Unit (ICU), and to define predictive factors associated with poor prognosis.

METHODS

A retrospective study over a 4-year period (2009 to 2012) of 694 patients with head injuries, incurred during road traffic accidents, admitted to the Intensive Care Unit (ICU) of a university hospital (Sfax-Tunisia). Basic demographic, clinical, biological, and radiological data were recorded on admission and during the ICU stay.

RESULTS

There were 592 males (85.3%), and 102 female patients. The mean age was at 31.8 ± 17.8 years (range 1-91). The mechanism of the accident was detailed in 666 patients (96%). The majority of the victims were motorcycle riders and/or passengers (40.5%), followed by pedestrians (29.1%). Extra-cranial pathology was present in 452 patients (65%). A total of 677 patients (97.6%) required intubation, mechanical ventilation, and sedation. Mean ICU stay was 16 ± 17.4 days. A total of 187 patients (26.9%) died during their hospital stay. The GOS performed within a mean delay of 6 months after hospital discharge was as follows: 198 deaths (28.5%), 13 vegetative state (1.9%), and 349 (50.3%) good recovery and/or moderate disability. A multivariate analysis showed that the factors which correlated with a poor prognosis (mortality and severe disability) were: age > 38 years, Glasgow coma scale score < 8, subdural hematoma, and development of secondary systemic insults (respiratory, circulatory, and metabolic).

CONCLUSION

In Tunisia, traumatic brain injury due to RTAs is a frequent cause of ICU admission, especially among young adults, and is associated with high mortality and morbidity rates. The majority of the victims were motorcycle riders and/or passengers and pedestrians. The factors associated with a poor outcome were: age > 38 years, Glasgow Coma Scale score < 8, subdural hematoma, and development of secondary systemic insults (respiratory, circulatory, and metabolic). As a consequence, prevention is highly warranted.

Diffuse Axonal Injury: Epidemiology, Outcome and Associated Risk Factors

Diffuse axonal injury (DAI), a type of traumatic injury, is known for its severe consequences. However, there are few studies describing the outcomes of DAI and the risk factors associated with it. This study aimed to describe the outcome for patients with a primary diagnosis of DAI 6 months after trauma and to identify sociodemographic and clinical factors associated with mortality and dependence at this time point. Seventy-eight patients with DAI were recruited from July 2013 to February 2014 in a prospective cohort study. Patient outcome was analyzed using the Extended Glasgow Outcome Scale (GOS-E) within 6 months of the traumatic injury. The mean Injury Severity Score was 35.0 (SD = 11.9), and the mean New Injury Severity Score (NISS) was 46.2 (SD = 15.9). Mild DAI was observed in 44.9% of the patients and severe DAI in 35.9%. Six months after trauma, 30.8% of the patients had died, and 45.1% had shown full recovery according to the GOS-E. In the logistic regression model, the severity variables - DAI with hypoxia, as measured by peripheral oxygen saturation, and hypotension with NISS value - had a statistically significant association with patient mortality; on the other hand, severity of DAI and length of hospital stay were the only significant predictors for dependence. Therefore, severity of DAI emerged as a risk factor for both mortality and dependence.

Rosiglitazone ameliorates diffuse axonal injury by reducing loss of tau and up-regulating caveolin-1 expression

Rosiglitazone up-regulates caveolin-1 levels and has neuroprotective effects in both chronic and acute brain injury. Therefore, we postulated that rosiglitazone may ameliorate diffuse axonal injury via its ability to up-regulate caveolin-1, inhibit expression of amyloid-beta precursor protein, and reduce the loss and abnormal phosphorylation of tau. In the present study, intraperitoneal injection of rosiglitazone significantly reduced the levels of amyloid-beta precursor protein and hyperphosphorylated tau (phosphorylated at Ser⁴⁰⁴(p-tau (S⁴⁰⁴)), and it increased the expression of total tau and caveolin-1 in the rat cortex. Our results show that rosiglitazone inhibits the expression of amyloid-beta precursor protein and lowers p-tau (S⁴⁰⁴) levels, and it reduces the loss of total tau, possibly by up-regulating caveolin-1. These actions of rosiglitazone may underlie its neuroprotective effects in the treatment of diffuse axonal injury.

Extended Anatomical Grading in Diffuse Axonal Injury Using MRI: Hemorrhagic Lesions in the Substantia Nigra and Mesencephalic Tegmentum Indicate Poor Long-Term Outcome

Clinical outcome after traumatic diffuse axonal injury (DAI) is difficult to predict. In this study, three magnetic resonance imaging (MRI) sequences were used to quantify the anatomical distribution of lesions, to grade DAI according to the Adams grading system, and to evaluate the value of lesion localization in combination with clinical prognostic factors to improve outcome prediction. Thirty patients (mean 31.2 years ±14.3 standard deviation) with severe DAI (Glasgow Motor Score [GMS] <6) examined with MRI within 1 week post-injury were included. Diffusion-weighted (DW), T2*-weighted gradient echo and susceptibility-weighted (SWI) sequences were used. Extended Glasgow outcome score was assessed after 6 months. Number of DW lesions in the thalamus, basal ganglia, and internal capsule and number of SWI lesions in the mesencephalon correlated significantly with outcome in univariate analysis. Age, GMS at admission, GMS at discharge, and low proportion of good monitoring time with cerebral perfusion pressure <60 mm Hg correlated significantly with outcome in univariate analysis. Multivariate analysis revealed an independent relation with poor outcome for age (p = 0.005) and lesions in the mesencephalic region corresponding to substantia nigra and tegmentum on SWI (p = 0.008). We conclude that higher age and lesions in substantia nigra and mesencephalic tegmentum indicate poor long-term outcome in DAI. We propose an extended MRI classification system based on four stages (stage I—hemispheric lesions, stage II—corpus callosum lesions, stage III—brainstem lesions, and stage IV—substantia nigra or mesencephalic tegmentum lesions); all are subdivided by age (≥/<30 years).

Red Blood Cell Transfusion in Patients With Traumatic Brain Injury: A Systematic Review and Meta-Analysis

Our objectives were to evaluate the frequency of red blood cell (RBC) transfusion in patients with traumatic brain injury (TBI) as well as potential determinants and outcomes associated with RBC transfusion in this population. We conducted a systematic review of cohort studies and randomized trials of patients with TBI. We searched Medline, Embase, the Cochrane Library, and BIOSIS databases from their inception up to April 2015. We selected studies of adult patients with acute TBI reporting data on RBC transfusions. Cumulative incidences of transfusion were pooled using random-effect models with a DerSimonian approach. To evaluate the association between RBC transfusion and potential determinants or clinical outcomes, we pooled risk ratios or mean differences with random-effect models and the Mantel-Haenszel method. We identified 24 eligible studies (17414 patients). After pooling data from 23 studies (7524 patients), approximately 36% (95% confidence interval [CI], 28-44; I(2) = 98%) of patients received RBC transfusion at some point during their hospital stay. Hemoglobin thresholds for transfusion were rarely available (reported in 9 studies) and varied from 6 to 10 g/dL. Glasgow Coma Scale scores at admission were lower in patients who were transfused than those who were not (3 cohort studies; 1371 patients; mean difference of 1.38 points [95% CI, 0.86-1.89]; I(2) = 12%). Mortality was not significantly different among transfused and nontransfused patients in univariate and multivariate meta-analyses. Hospital length of stay was longer among patients receiving RBC transfusion compared to those who did not (3 studies; n = 455; mean difference, 9.58 days [95% CI, 3.94-15.22]; I(2) = 74%). Results should be considered cautiously due to the high heterogeneity and high risk of confounding from the observational nature of included studies. Red blood cell transfusion is frequent in patients with TBI, and transfusion practices varied widely between studies. Current published data highlight the lack of clinical evidence guiding transfusion strategies in TBI.

Paroxysmal sympathetic hyperactivity in pediatric traumatic brain injury: A case series of four patients

Paroxysmal sympathetic hyperactivity (PSH) is a condition in which there is extreme autonomic dysregulation leading to multiple episodes of sympathetic hyperactivity. Its occurrence after traumatic brain injury (TBI) in pediatric population is a neglected scenario. In our series, all pediatric patients with moderate and severe head injuries were studied and those patients who developed PSH were monitored for the PSH episodes. Four children out of 36 cases of pediatric severe traumatic brain injury developed features of PSH. Admission GCS of 3 children were 4/15 and 1 child was 6/15 and each of them had an ICU stay of more than 2 weeks and a poor DRS score at discharge. The presence of PSH is known to produce poorer outcome in terms of overall mortality, time needed for recovery, chances of developing infections, etc. which was also seen in these cases presented here. Though some studies have provided guidelines for the management of PSH like symptomatic management and use of drugs like clonidine, bromocriptine, benzodiazepines, and gabapentin, strict management guidelines are not established and exact incidence in pediatric population is not determined.

Magnetic resonance imaging as an alternative to computed tomography in select patients with traumatic brain injury: a retrospective comparison

OBJECT

Traumatic head injury (THI) is a highly prevalent condition in the United States, and concern regarding excess radiation-related cancer mortality has placed focus on limiting the use of CT in the evaluation of pediatric patients with THI. Given the success of rapid-acquisition MRI in the evaluation of ventriculoperitoneal shunt malfunction in pediatric patient populations, this study sought to evaluate the sensitivity of MRI in the setting of acute THI.

METHODS

Medical records of 574 pediatric admissions for THI to a Level 1 trauma center over a 10-year period were retrospectively reviewed to identify patients who underwent both CT and MRI examinations of the head within a 5-day period. Thirty-five patients were found, and diagnostic images were available for 30 patients. De-identified images were reviewed by a neuroradiologist for presence of any injury, intracranial hemorrhage, diffuse axonal injury (DAI), and skull fracture. Radiology reports were used to calculate interrater reliability scores. Baseline demographics and concordance analysis was performed with Stata version 13.

RESULTS

The mean age of the 30-patient cohort was 8.5 ± 6.7 years, and 63.3% were male. The mean Injury Severity Score was 13.7 ± 9.2, and the mean Glasgow Coma Scale score was 9 ± 5.7. Radiology reports noted 150 abnormal findings. CT scanning missed findings in 12 patients; the missed findings included DAI (n = 5), subarachnoid hemorrhage (n = 6), small subdural hematomas (n = 6), cerebral contusions (n = 3), and an encephalocele. The CT scan was negative in 3 patients whose subsequent MRI revealed findings. MRI missed findings in 13 patients; missed findings included skull fracture (n = 5), small subdural hematomas (n = 4), cerebral contusions (n = 3), subarachnoid hemorrhage (n = 3), and DAI (n = 1). MRI was negative in 1 patient whose preceding CT scan was read as positive for injury. Although MRI more frequently reported intracranial findings than CT scanning, there was no statistically significant difference between CT and MRI in the detection of any intracranial injury (p = 0.63), DAI (p = 0.22), or intracranial hemorrhage (p = 0.25). CT scanning tended to more frequently identify skull fractures than MRI (p = 0.06).

CONCLUSIONS

MRI may be as sensitive as CT scanning in the detection of THI, DAI, and intracranial hemorrhage, but missed skull fractures in 5 of 13 patients. MRI may be a useful alternative to CT scanning in select stable patients with mild THI who warrant neuroimaging by clinical decision rules.

The occurrence of diffuse axonal injury in the brain: associated with the accumulation and clearance of myelin debris

The accumulation of myelin debris may be a major contributor to the inflammatory response after diffuse axonal injury. In this study, we examined the accumulation and clearance of myelin debris in a rat model of diffuse axonal injury. Oil Red O staining was performed on sections from the cerebral cortex, hippocampus and brain stem to identify the myelin debris. Seven days after diffuse axonal injury, many Oil Red O-stained particles were observed in the cerebral cortex, hippocampus and brain stem. In the cerebral cortex and hippocampus, the amount of myelin debris peaked at 14 days after injury, and decreased significantly at 28 days. In the brain stem, the amount of myelin debris peaked at 7 days after injury, and decreased significantly at 14 and 28 days. In the cortex and hippocampus, some myelin debris could still be observed at 28 days after diffuse axonal injury. Our findings suggest that myelin debris may persist in the rat central nervous system after diffuse axonal injury, which would hinder recovery.

Intraventricular hemorrhage on initial computed tomography as marker of diffuse axonal injury after traumatic brain injury

Intraventricular hemorrhage (IVH) on initial computed tomography (CT) was reported to predict lesions of diffuse axonal injury (DAI) in the corpus callosum (CC) on subsequent magnetic resonance imaging (MRI). We aimed to examine the relationship between initial CT findings and DAI lesions detected on MRI as well as the relationship between the severity of IVH (IVH score) and severity of DAI (DAI staging). A consecutive 140 patients with traumatic brain injury (TBI) who underwent MRI within 30 days after onset were revisited. We reviewed their initial CT for the following six findings: Status of basal cistern, status of mid-line shift, epidural hematoma, IVH, subarachnoid hemorrhage, and volume of hemorrhagic mass and IVH score were assigned in each patient. Based on MRI findings, patients were divided into DAI and non-DAI groups and were assigned a DAI staging. Then, to confirm that the IVH on initial CT predicts DAI lesions on MRI, we used multi-variate analysis of the six CT findings, including IVH, and examined the relationship between IVH score and DAI staging. The IVH detected on CT was the only predictor of DAI (p=0.0139). The IVH score and DAI staging showed significant positive correlation (p<0.0003). IVH score in DAI stage 3 (with DAI involving the brain stem; p=0.0025) or stage 2 (with DAI involving CC; p=0.0042) was significantly higher than that of DAI stage 0 (no DAI lesions). In conclusion, IVH on initial CT is the only marker of DAI on subsequent MRI, specifically severe DAI (stage 2 or 3).

Pediatric neurotrauma

Traumatic brain injury (TBI) is the leading cause of death and disability in children over 1 year of age. Knowledge about the age-specific types of injury and how to manage children with neurotrauma is essential to understanding and recognizing the extent and degree of injury and to optimize outcomes. In this article, we review the epidemiology, pathophysiology, and clinical management of pediatric neurotrauma.

Prognosis in prolonged coma patients with diffuse axonal injury assessed by somatosensory evoked potentia

A total of 43 prolonged coma patients with diffuse axonal injury received the somatosensory evoked potential examination one month after injury in the First Affiliated Hospital, School of Medicine, Zhejiang University in China. Somatosensory evoked potentials were graded as normal, abnormal or absent (grades I–III) according to N20 amplitude and central conduction time. The outcome in patients with grade III somatosensory evoked potential was in each case unfavorable. The prognostic accuracy of grade III somatosensory evoked potential for unfavorable and non-awakening outcome was 100% and 80%, respectively. The prognostic accuracy of grade I somatosensory evoked potential for favorable and wakening outcome was 86% and 100%, respectively. These results suggest that somatosensory evoked potential grade is closely correlated with coma severity and degree of recovery. Somatosensory evoked potential is a valuable diagnostic tool to assess prognosis in prolonged coma patients with diffuse axonal injury.

Dysautonomia after pediatric brain injury

AIM

Dysautonomia after brain injury is a diagnosis based on fever, tachypnea, hypertension, tachycardia, diaphoresis, and/or dystonia. It occurs in 8 to 33% of adults with brain injury and is associated with poor outcome. We hypothesized that children with brain injury with dysautonomia have worse outcomes and prolonged rehabilitation, and sought to determine the prevalence of dysautonomia in children and to characterize its clinical features.

METHOD

We developed a database of children (n = 249, 154 males, 95 females; mean [SD] age 11 years 10 months [5 y 7 mo]) with traumatic brain injury, cardiac arrest, stroke, infection of the central nervous system, or brain neoplasm admitted for rehabilitation to The Children's Institute of Pittsburgh between 2002 and 2009. Dysautonomia diagnosis, injury type, clinical signs, length of stay, and Functional Independence Measure for Children (WeeFIM) testing were extracted from medical records, and analysed for differences between groups with and without dysautonomia.

RESULTS

Dysautonomia occurred in 13% of children with brain injury (95% confidence interval 9.3-18.0%), occurring in 10% after traumatic brain injury and 31% after cardiac arrest. The combination of hypertension, diaphoresis, and dystonia best predicted a diagnosis of dysautonomia (area under the curve = 0.92). Children with dysautonomia had longer stays, worse WeeFIM scores, and improved less on the score's motor component (all p ≤ 0.001).

INTERPRETATION

Dysautonomia is common in children with brain injury and is associated with prolonged rehabilitation. Prospective study and standardized diagnostic approaches are needed to maximize outcomes.

The young brain and concussion: imaging as a biomarker for diagnosis and prognosis

Concussion (mild traumatic brain injury (mTBI)) is a significant pediatric public health concern. Despite increased awareness, a comprehensive understanding of the acute and chronic effects of concussion on central nervous system structure and function remains incomplete. Here we review the definition, epidemiology, and sequelae of concussion within the developing brain, during childhood and adolescence, with current data derived from studies of pathophysiology and neuroimaging. These findings may contribute to a better understanding of the neurological consequences of traumatic brain injuries, which in turn, may lead to the development of brain biomarkers to improve identification, management and prognosis of pediatric patients suffering from concussion.