Mortality and Morbidity From Moderate to Severe Traumatic Brain Injury in Argentina

Clinical Epidemiology of Extracranial Injuries in Severe Pediatric Traumatic Brain Injury in South America

BACKGROUND

Severe traumatic brain injury (TBI) is a leading cause of pediatric mortality, with a disproportionate burden on low- and middle-income countries. The impact of concomitant extracranial injury (ECI) on these patients remains unclear. This study is the first to characterize the epidemiology and clinical course of severe pediatric TBI with extracranial injuries in any South American country.

METHODS

We conducted a secondary analysis of baseline data collected prior to implementation of a clinical trial on TBI care in Argentina, Paraguay, and Chile from September 2019 to July 2020. Patients ≤18 years with CT evidence of TBI, and a Glasgow coma scale (GCS) score ≤8 were recruited. Patients were initially stratified by highest non-head abbreviated injury scale (AIS): isolated TBI (AIS=0), minor extracranial injury (MEI; AIS=1-2), and serious extracranial injury (SEI; AIS≥3). Patients were subsequently stratified by mechanism of injury. Intergroup differences were compared using ANOVA, two-tailed unpaired t-tests, and chi-square tests.

RESULTS

Among the 116 children included, 33 % (n = 38) had an isolated TBI, 34 % (n = 39) had MEI, and 34 % (n = 39) had SEI. Facial (n = 53), thoracic (n = 44), and abdominal (n = 31) injuries were the most common ECIs. At discharge, there were no significant differences in median GCS, GOS, or GOS-extended between groups. Patients with SEI had a longer hospital LOS than those with isolated TBI (median 28.0 (IQR 10.6-40.1) vs 11.9 (IQR 8.7-20.7) days, p = 0.013). The most common mechanisms of injury were road traffic injuries (RTIs) (n = 50, 43 %) and falls (n = 35, 30 %). Patients with RTI-associated TBIs were more likely to be older (median 11.0 (IQR 3.0-14.0) vs 2.0 (IQR 0.8-7.0) years, p<0.001) and more likely to have an ECI (86% vs 54 %, respectively; p = 0.003). ICU and Hospital LOS for RTI patients (median 10.5 (IQR 6.1-21.1) and 24.1 (IQR 11.5-40.4) days) were longer than those of fall patients (median 6.1 (IQR 2.6-8.9) and 13.7 (IQR 7.7-24.5) days).

CONCLUSIONS

Extracranial injuries are common in South American patients with severe TBI. Severe ECI is more frequently associated with RTIs and can result in a higher rate of surgical procedures and LOS. Further strategies are needed to characterize the prevention and treatment of severe pediatric TBI in the South American context.

Incidence, and factors associated with moderate/severe pediatric traumatic brain injury in children aged 5-15 years in western, Mexico

OBJECTIVE

The study objectives were to estimate the standardized incidence and evaluate factors associated with moderate/severe pediatric traumatic brain injury (p-TBI) in children aged 5-15 years in Western, Mexico.

METHODS

The study was cross-sectional in design. We estimated the standardized incidence of moderate/severe p-TBI using the direct methods of the World Health Organization (WHO) standard populations. We utilized the Glasgow Coma Scale (GCS) to identify moderate/severe p-TBI patients (GCS ≤ 13). Logistic regression analysis was applied to evaluate variables associated with moderate/severe p-TBI.

RESULTS

The standardized incidence of patients diagnosed with moderate/severe p-TBI was 31.0/100,000 person-years (95 % CI 28.7-33.4). According to age, the moderate/severe TBI group was included. A total of 254 (38.5 %) patients were aged 5-9 years, 343 (52.0 %) were aged 10-14 years, and 62 (9.5 %) were aged 15 years. Factors associated with moderate/severe TBI in the crude analysis were male sex (OR 5.50, 95 % CI 4.16-7.39, p < 0.001), primary school (OR 2.15, 95 % CI 1.62-2.84, p < 0.001), and falls (OR 1.34, 95 % CI 1.02-1.77, p = 0.035). Factors associated with moderate/severe p-TBI in the adjusted analysis were male sex (OR 6.12, 95 % CI 4.53-8.29, p < 0.001), primary school (OR 3.25, 95 % CI 2.31-4.55, p < 0.001), and falls (OR 1.78, 95 % CI 1.28-2.47, p < 0.001).

CONCLUSION

The incidence of moderate/severe p-TBI in children aged 5-15 years in western Mexico in this study was higher than that in other studies. One of the biggest factors associated with moderate/severe p-TBI was male sex, specifically those with lower education levels and those who were prone to falls.

Systematic Review of the Diagnostic and Clinical Utility of Salivary microRNAs in Traumatic Brain Injury (TBI)

Research in traumatic brain injury (TBI) is an urgent priority, as there are currently no TBI biomarkers to assess the severity of injury, to predict outcomes, and to monitor recovery. Small non-coding RNAs (sncRNAs) including microRNAs can be measured in saliva following TBI and have been investigated as potential diagnostic markers. The aim of this systematic review was to investigate the diagnostic or prognostic ability of microRNAs extracted from saliva in human subjects. PubMed, Embase, Scopus, PsycINFO and Web of Science were searched for studies that examined the association of saliva microRNAs in TBI. Original studies of any design involving diagnostic capacity of salivary microRNAs for TBI were selected for data extraction. Nine studies met inclusion criteria, with a heterogeneous population involving athletes and hospital patients, children and adults. The studies identified a total of 188 differentially expressed microRNAs, with 30 detected in multiple studies. MicroRNAs in multiple studies involved expression change bidirectionality. The study design and methods involved significant heterogeneity that precluded meta-analysis. Early data indicates salivary microRNAs may assist with TBI diagnosis. Further research with consistent methods and larger patient populations is required to evaluate the diagnostic and prognostic potential of saliva microRNAs.

Estrogen Alleviates Sex-Dependent Differences in Lung Bacterial Clearance and Mortality Secondary to Bacterial Pneumonia after Traumatic Brain Injury

Traumatic brain injury (TBI) is the leading cause of injury-related death and disability in patients under the age of 46 years. Survivors of the initial injury often endure systemic complications such as pulmonary infection, and Pseudomonas aeruginosa is one of the most common causes of nosocomial pneumonia in intensive care units. Female patients are less likely to develop secondary pneumonia after TBI, and pre-clinical studies have revealed a salutary role for estrogen after trauma. Therefore, we hypothesized that female mice would experience less mortality after post-TBI pneumonia with P. aeruginosa. We employed a mouse model of TBI followed by P. aeruginosa pneumonia. Male mice had greater mortality and impaired lung bacterial clearance after post-TBI pneumonia compared with female mice. This was confirmed as a difference in sex hormones, as oophorectomized wild-type mice had mortality and lung bacterial clearance similar to male mice. There were differences in tumor necrosis factor-α secretion in male and female alveolar macrophages after P. aeruginosa infection. Finally, injection of male or oophorectomized wild-type female mice with estrogen restored lung bacterial clearance and prevented mortality. Our model of TBI followed by P. aeruginosa pneumonia is among the first to reveal sex dimorphism in secondary, long-term TBI complications.

Aberrant ER Stress Induced Neuronal-IFNβ Elicits White Matter Injury Due to Microglial Activation and T-Cell Infiltration after TBI

Persistent endoplasmic reticulum (ER) stress in neurons is associated with activation of inflammatory cells and subsequent neuroinflammation following traumatic brain injury (TBI); however, the underlying mechanism remains elusive. We found that induction of neuronal-ER stress, which was mostly characterized by an increase in phosphorylation of a protein kinase R-like ER kinase (PERK) leads to release of excess interferon (IFN)β due to atypical activation of the neuronal-STING signaling pathway. IFNβ enforced activation and polarization of the primary microglial cells to inflammatory M1 phenotype with the secretion of a proinflammatory chemokine CXCL10 due to activation of STAT1 signaling. The secreted CXCL10, in turn, stimulated the T-cell infiltration by serving as the ligand and chemoattractant for CXCR3⁺ T-helper 1 (Th1) cells. The activation of microglial cells and infiltration of Th1 cells resulted in white matter injury, characterized by impaired myelin basic protein and neurofilament NF200, the reduced thickness of corpus callosum and external capsule, and decline of mature oligodendrocytes and oligodendrocyte precursor cells. Intranasal delivery of CXCL10 siRNA blocked Th1 infiltration but did not fully rescue microglial activation and white matter injury after TBI. However, impeding PERK-phosphorylation through the administration of GSK2656157 abrogated neuronal induction of IFNβ, switched microglial polarization to M2 phenotype, prevented Th1 infiltration, and increased Th2 and Treg levels. These events ultimately attenuated the white matter injury and improved anxiety and depressive-like behavior following TBI.SIGNIFICANCE STATEMENT A recent clinical study showed that human brain trauma patients had enhanced expression of type-1 IFN; suggests that type-1 IFN signaling may potentially influence clinical outcome in TBI patients. However, it was not understood how TBI leads to an increase in IFNβ and whether induction of IFNβ has any influence on neuroinflammation, which is the primary reason for morbidity and mortality in TBI. Our study suggests that induction of PERK phosphorylation, a characteristic feature of ER stress is responsible for an increase in neuronal IFNβ, which, in turn, activates microglial cells and subsequently manifests the infiltration of T cells to induce neuroinflammation and subsequently white matter injury. Blocking PERK phosphorylation using GSK2656157 (or PERK knockdown) the whole cascade of neuroinflammation was attenuated and improved cognitive function after TBI.

Chronic Central Pain Among Community-Dwelling Survivors of Moderate-to-Severe Traumatic Brain Injury: A Quantitative Sensory Testing Study

Background:

Central pain associated with changes in sensory thresholds is one of the most enduring consequences of major trauma. Yet it remains sparsely studied among community-dwelling survivors of moderate-to-severe traumatic brain injury (TBI).

Purpose:

To describe and compare thermal and mechanical sensory thresholds in home-based patients with and without central pain after moderate-to-severe TBI with a cohort of healthy controls.

Design:

Cross-sectional.

Method:

Thresholds for cold/heat detection, thermal pain, touch, and distorted sensation were gathered using quantitative sensory testing (QST). QST was performed on the painful and contralateral pain-free body regions in TBI participants with pain (TBI-P) and on both forearms in TBI participants without pain (TBI-NP) and healthy controls (HC). Central pain was characterized using the Brief Pain Inventory–Short Form.

Results:

We tested 16 TBI-P patients, 17 TBI-NP patients, and 16 HC. Mean time since injury for TBI patients was 24 ± 15 months. TBI-P and TBI-NP patients showed significant loss in innocuous mechanical sensitivity compared to HC ( F = 18.929; Bonferroni-adjusted p ≤ .001). Right–left differences in cold pain sensations were significantly larger in TBI-P than in TBI-NP and HC participants ( F = 14.352; Bonferroni-adjusted p ≤ .001). Elevated heat sensitivity thresholds were also observed in TBI-P participants but remained within normal range.

Conclusion:

Damage to cutaneous mechanoreceptors is a necessary, but not sufficient, condition for the development of chronic central pain following TBI. Damage or incomplete recovery of cutaneous thermoreceptors may be a contributing factor to chronic pain after TBI.

Intensive care treatments associated with favorable discharge outcomes in Argentine children with severe traumatic brain injury: For the South American Guideline Adherence Group

Objective

Little is known about the critical care management of children with traumatic brain injury (TBI) in low middle income countries. We aimed to identify indicators of intensive care unit (ICU) treatments associated with favorable outcomes in Argentine children with severe TBI.

Methods

We conducted a secondary analysis of data from patients previously enrolled in a prospective seven center study of children with severe TBI who were admitted to an ICU in one of the seven study centers. Severe TBI was defined by head AIS ≥ 3, head CT with traumatic lesion, and admission GCS < 9. Seven indicators of best practice TBI care were examined. The primary outcome was discharge Pediatric Cerebral Performance Category Scale [PCPC] and Pediatric Overall Performance category Scale [POPC]. We also examined variation in ICU care and in-patient mortality.

Results

Of the 117 children, 67% were male and 7.5 (4.3) years on average, 92% had isolated TBI. Hypotension (54%) was more common than hypoxia (28%) and clinical or radiographic signs of high intracranial pressure (ICP) were observed in 92%. Yet, ICP monitoring occurred in 60% and hyperosmolar therapy was used in only 36%. Adherence to indicators of best TBI practice ranged from 55.6% to 83.7% across the seven centers and adherence was associated with favorable discharge PCPC (aRR 0.98; 95% CI [0.96, 0.99]), and POPC (aRR 0.98; 95% CI [0.96, 0.99]). Compared to patients whose adherence rates were below 65%, patients whose adherence rates were higher between 75%-100% had better discharge PCPC (aRR 0.28; 95% CI [0.10, 0.83]) and POPC (aRR 0.32; 95% CI [0.15, 0.73]. Two indicators were associated with favorable discharge PCPC: Avoidance of hypoxia (aRR 0.46; 95% CI [0.23, 0.93]), and Nutrition started in 72 hours (aRR 0.45; 95% CI [0.21, 0.99]). Avoiding hypoxia was also associated with favorable discharge POPC (aRR 0.47; 95% CI [0.22, 0.99]).

Conclusion

There is variation in Argentine ICU practice in the care of children with severe TBI. Second insults are common and hyperosmolar therapy use is uncommon. Adherence to best practice TBI care by avoiding hypoxia and providing timely nutrition were associated with significantly favorable discharge outcomes. Implementing strategies that prevent hypoxia and facilitate early nutrition in the ICUs are urgently needed to improve pediatric TBI outcomes.

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.

An insight into the vision impairment following traumatic brain injury

Traumatic brain injury (TBI) is one of the major cause of morbidity and mortality and it affects more than 1.7 million Americans each year. Depending on its location and severity, TBI leads to structural and functional damage in several parts of the brain such as cranial nerves, optic nerve tract or other circuitry involved in vision, and occipital lobe. As a result, the function associated with vision processing and perception are significantly affected and cause blurred vision, double vision, decreased peripheral vision and blindness. In this mini-review, we will focus the recent progress made to understand the pathology and underlying cellular/molecular mechanisms involved in the impairment of the integrity of visual systems following TBI.

Activation of PERK Elicits Memory Impairment through Inactivation of CREB and Downregulation of PSD95 After Traumatic Brain Injury

The PKR-like ER kinase (PERK), a transmembrane protein, resides in the endoplasmic reticulum (ER). Its activation serves as a key sensor of ER stress, which has been implicated in traumatic brain injury (TBI). The loss of memory is one of the most common symptoms after TBI, but the precise role of PERK activation in memory impairment after TBI has not been well elucidated. Here, we have shown that blocking the activation of PERK using GSK2656157 prevents the loss of dendritic spines and rescues memory deficits after TBI. To elucidate the molecular mechanism, we found that activated PERK phosphorylates CAMP response element binding protein (CREB) and PSD95 directly at the S129 and T19 residues, respectively. Phosphorylation of CREB protein prevents its interaction with a coactivator, CREB-binding protein, and subsequently reduces the BDNF level after TBI. Conversely, phosphorylation of PSD95 leads to its downregulation in pericontusional cortex after TBI in male mice. Treatment with either GSK2656157 or overexpression of a kinase-dead mutant of PERK (PERK-K618A) rescues BDNF and PSD95 levels in the pericontusional cortex by reducing phosphorylation of CREB and PSD95 proteins after TBI. Similarly, administration of either GSK2656157 or overexpression of PERK-K618A in primary neurons rescues the loss of dendritic outgrowth and number of synapses after treatment with a PERK activator, tunicamycin. Therefore, our study suggests that inhibition of PERK phosphorylation could be a potential therapeutic target to restore memory deficits after TBI.SIGNIFICANCE STATEMENT Traumatic brain injury (TBI) is the leading cause of death and disability around the world and affects 1.7 million Americans each year. Here, we have shown that TBI-activated PKR-like ER kinase (PERK) is responsible for memory deficiency, which is the most common problem in TBI patients. A majority of PERK's biological activities have been attributed to its function as an eIF2α kinase. However, our study suggests that activated PERK mediates its function via increasing phosphorylation of CAMP response element binding protein (CREB) and PSD95 after TBI. Blocking PERK phosphorylation rescues spine loss and memory deficits independently of phosphorylation of eIF2α. Therefore, our study suggests that CREB and PSD95 are novel substrates of PERK, so inhibition of PERK phosphorylation using GSK2656157 would be beneficial against memory impairment after TBI.

Benchmarking Prehospital and Emergency Department Care for Argentine Children with Traumatic Brain Injury: For the South American Guideline Adherence Group

Objective

There is little information on the type of early care provided to children with traumatic brain injury (TBI) in low middle income countries. We benchmarked early prehospital [PH] and emergency department [ED] pediatric TBI care in Argentina.

Methods

We conducted a secondary analysis of data from patients previously enrolled in a prospective seven center study of children with TBI. Eligible participants were patients 0–18 years, and had diagnosis of TBI (admission Glasgow Coma scale score [GCS] < 13 or with GCS 14–15 and abnormal head CT scan within 48 hours of admission, and head AIS > 0). Outcomes were transport type, transport time, PH and ED adherence to best practice, and discharge Pediatric Cerebral Performance Category Scale (PCPC) and Pediatric Overall Performance category Scale (POPC).

Results

Of the 366 children, mean age was 8.7 (5.0) years, 58% were male, 90% had isolated TBI and 45.4% were transported by private vehicle. 50 (34.7%) of the 144 children with severe TBI (39.3% of all TBI patients) were transported by private vehicle. Most (267; 73%) patients received initial TBI care at an index hospital prior to study center admission, including children with severe (81.9%) TBI. Transport times were shorter for those patients who were directly transported by ambulance to study center than for the whole cohort (1.4 vs.5.5 hours). Ambulance blood pressure data were recorded in 30.9%. ED guideline adherence rate was higher than PH guideline adherence rate (84.8% vs. 26.4%). For patients directly transferred from scene to study trauma centers, longer transport time was associated with worse discharge outcome (PCPC aOR 1.10 [1.04, 1.18] and (POPC aOR 1.10 [1.04, 1.18]). There was no relationship between PH or ED TBI guideline adherence rate and discharge POPC and PCPC.

Conclusion

This study benchmarks early pediatric TBI care in Argentina and shows that many critically injured children with TBI do not receive timely or best practice PH care, that PH guideline adherence rate is low and that longer transport time was associated with poor discharge outcomes for patients with direct transfer status. There is an urgent need to improve the early care of children with TBI in Argentina, especially timely transportation to a hospital.

How Do Intensity and Duration of Rehabilitation Services Affect Outcomes From Severe Traumatic Brain Injury? A Natural Experiment Comparing Health Care Delivery Systems in 2 Developed Nations

OBJECTIVE

To determine the effects of inpatient and outpatient treatment intensity on functional and emotional well-being outcomes at 1 year after severe traumatic brain injury (TBI).

DESIGN

Prospective, quasiexperimental study comparing outcomes in a U.S. TBI treatment center with those in a Denmark (DK) center providing significantly greater intensity and duration of rehabilitation.

SETTING

Inpatient and outpatient TBI rehabilitation.

PARTICIPANTS

Persons with severe TBI (N=274).

INTERVENTIONS

Inpatient rehabilitation interventions were counted daily by discipline. Outpatient treatments were estimated per discipline using a structured interview administered to patients, caregivers, or both, at 12 months.

MAIN OUTCOME MEASURES

FIM, Glasgow Outcome Scale-Extended, Disability Rating Scale, Participation Assessment with Recombined Tools-Objective, Perceived Quality of Life, Medical Outcomes Study 12-Item Short-Form Health Survey, Brief Symptom Inventory-18-item version.

RESULTS

Despite identical inclusion criteria, patient severity on admission was greater at the DK site. After adjustment for patient/injury characteristics, there were no site differences in either functional or emotional outcome at 12 months. Significantly more inpatient plus outpatient treatment was administered to DK patients than to those in the U.S. For functional but not emotional treatments, more severely impaired patients received higher doses. One-year outcomes were predicted by admission severity, age, employment, and other baseline characteristics.

CONCLUSIONS

Contrary to expectation, DK patients who received significantly more rehabilitation services during the year after severe TBI did not differ in outcome from their less intensively treated U.S. counterparts, after adjusting for initial severity. The negative association of functional treatment dose with extent of early disability suggests that dose was driven by unmeasured factors reflecting need for services. Improved measures of injury-related factors driving treatment allocation are needed to model the independent effects of treatment on outcomes.

Postdischarge Care of Pediatric Traumatic Brain Injury in Argentina: A Multicenter Randomized Controlled Trial

OBJECTIVE

To develop, in partnership with families of children with traumatic brain injury, a postdischarge intervention that is effective, simple, and sustainable.

DESIGN

Randomized Controlled Trial.

SETTING

Seven Level 1 Pediatric Trauma Centers in Argentina.

PATIENTS

Persons less than 19 years of age admitted to one of the study hospitals with a diagnosis of severe, moderate, or complicated mild traumatic brain injury and were discharged alive.

INTERVENTIONS

Patients were randomly assigned to either the intervention or standard care group. A specially trained Community Resource Coordinator was assigned to each family in the intervention group. We hypothesized that children with severe, moderate, and complicated mild traumatic brain injury who received the intervention would have significantly better functional outcomes at 6 months post discharge than those who received standard care. We further hypothesized that there would be a direct correlation between patient outcome and measures of family function.

MEASUREMENTS AND MAIN RESULTS

The primary outcome measure was a composite measured at 6 months post injury. There were 308 patients included in the study (61% men). Forty-four percent sustained a complicated mild traumatic brain injury, 18% moderate, and 38% severe. Sixty-five percent of the patients were 8 years old or younger, and over 70% were transported to the hospital without ambulance assistance. There was no significant difference between groups on the primary outcome measure. There was a statistically significant correlation between the primary outcome measure and the scores on the Family Impact Module of the Pediatric Quality of Life Inventory (ρ = 0.57; p < 0.0001). Children with better outcomes lived with families reporting better function at 6 months post injury.

CONCLUSIONS

Although no significant effect of the intervention was demonstrated, this study represents the first conducted in Latin America that documents the complete course of treatment for pediatric patients with traumatic brain injury spanning hospital transport through hospital care and into the postdischarge setting.

Treatment with an activator of hypoxia-inducible factor 1, DMOG provides neuroprotection after traumatic brain injury

Traumatic brain injury (TBI) is one of the major cause of morbidity and mortality and it affects more than 1.7 million people in the USA. A couple of regenerative pathways including activation of hypoxia-inducible transcription factor 1 alpha (HIF-1α) are initiated to reduce cellular damage following TBI; however endogenous activation of these pathways is not enough to provide neuroprotection after TBI. Thus we aimed to see whether sustained activation of HIF-1α can provide neuroprotection and neurorepair following TBI. We found that chronic treatment with dimethyloxaloylglycine (DMOG) markedly increases the expression level of HIF-1α and mRNA levels of its downstream proteins such as Vascular endothelial growth factor (VEGF), Phosphoinositide-dependent kinase-1 and 4 (PDK1, PDK4) and Erythropoietin (EPO). Treatment of DMOG activates a major cell survival protein kinase Akt and reduces both cell death and lesion volume following TBI. Moreover, administration of DMOG augments cluster of differentiation 31 (CD31) staining in pericontusional cortex after TBI, which suggests that DMOG stimulates angiogenesis after TBI. Treatment with DMOG also improves both memory and motor functions after TBI. Taken together our results suggest that sustained activation of HIF-1α provides significant neuroprotection following TBI.

Traumatic Brain Injury and Peripheral Immune Suppression: Primer and Prospectus

Nosocomial infections are a common occurrence in patients following traumatic brain injury (TBI) and are associated with an increased risk of mortality, longer length of hospital stay, and poor neurological outcome. Systemic immune suppression arising as a direct result of injury to the central nervous system (CNS) is considered to be primarily responsible for this increased incidence of infection, a view strengthened by recent studies that have reported novel changes in the composition and function of the innate and adaptive arms of the immune system post-TBI. However, our knowledge of the mechanisms that underlie TBI-induced immune suppression is equivocal at best. Here, after summarizing our current understanding of the impact of TBI on peripheral immunity and discussing CNS-mediated regulation of immune function, we propose roles for a series of novel mechanisms in driving the immune suppression that is observed post-TBI. These mechanisms, which have never been considered before in the context of TBI-induced immune paresis, include the CNS-driven emergence into the circulation of myeloid-derived suppressor cells and suppressive neutrophil subsets, and the release from injured tissue of nuclear and mitochondria-derived damage associated molecular patterns. Moreover, in an effort to further our understanding of the mechanisms that underlie TBI-induced changes in immunity, we pose throughout the review a series of questions, which if answered would address a number of key issues, such as establishing whether manipulating peripheral immune function has potential as a future therapeutic strategy by which to treat and/or prevent infections in the hospitalized TBI patient.

Multimodality monitoring consensus statement: monitoring in emerging economies

The burden of disease and so the need for care is often greater at hospitals in emerging economies. This is compounded by frequent restrictions in the delivery of good quality clinical care due to resource limitations. However, there is substantial heterogeneity in this economically defined group, such that advanced brain monitoring is routinely practiced at certain centers that have an interest in neurocritical care. It also must be recognized that significant heterogeneity in the delivery of neurocritical care exists even within individual high-income countries (HICs), determined by costs and level of interest. Direct comparisons of data between HICs and the group of low- and middle-income countries (LAMICs) are made difficult by differences in patient demographics, selection for ICU admission, therapies administered, and outcome assessment. Evidence suggests that potential benefits of multimodality monitoring depend on an appropriate environment and clinical expertise. There is no evidence to suggest that patients in LAMICs where such resources exist should be treated any differently to patients from HICs. The potential for outcome benefits in LAMICs is arguably greater in absolute terms because of the large burden of disease; however, the relative cost/benefit ratio of such monitoring in this setting must be viewed in context of the overall priorities in delivering health care at individual institutions.

Comorbidities: a key issue in patients with disorders of consciousness

The aim of this study was to identify the impact of comorbidities on outcomes of patients with vegetative state (VS) or minimally conscious state (MCS). All patients in VS or MCS consecutively admitted to two postacute care units within a 1-year period were evaluated at baseline and at 6 months through the Coma Recovery Scale-Revised Version and the Disability Rating Scale (DRS). Comorbidities were also recorded for each patient along the same period. Six-month outcomes included death, full recovery of consciousness, and functional improvement. One hundred and thirty-nine patients (88 male and 51 female; median age, 59 years) were included. Ninety-seven patients were in VS (70%) and 42 in MCS (30%). At 6 months, 33 patients were dead (24%), 39 had a full recovery of consciousness (28%), and 67 remained in VS or MCS (48%). According to DRS scores, 40% of patients (n=55) showed a functional improvement in the level of disability. One hundred and thirty patients (94%) showed at least one comorbidity. Severity of comorbidities (hazard ratio [HR]=2.8; 95% confidence interval [CI], 1.71-4.68; p<0.001) and the presence of ischemic or organic heart diseases (HR=2.6; 95% CI, 1.21-5.43; p=0.014) were the strongest predictors of death, together with increasing age (HR=1.0; 95% CI, 1.0-1.06; p=0.033). Respiratory diseases and arrhythmias without organic heart diseases were negative predictors of full recovery of consciousness (odds ratio [OR]=0.3; 95% CI, 0.12-0.7; p=0.006; OR=0.2; 95% CI, 0.07-0.43; p<0.001) and functional improvement (OR=0.4; 95% CI, 0.15-0.85, p=0.020; OR=0.2; 95% CI, 0.08-0.45; p<0.001). Our data show that comorbidities are common in these patients and some of them influence recovery of consciousness and outcomes.

Medical complications during inpatient rehabilitation among patients with traumatic disorders of consciousness

OBJECTIVE

To assess the incidence of medical complications in patients with recent traumatic disorders of consciousness (DOCs).

DESIGN

Data on adverse events in a placebo controlled trial of amantadine hydrochloride revealed no group difference, which allowed these events to be reanalyzed descriptively as medical complications experienced by the 2 groups collectively.

SETTING

Eleven clinical facilities in the United States, Denmark, and Germany with specialty rehabilitation programs for patients with DOCs.

PARTICIPANTS

Patients (N=184) with nonpenetrating traumatic brain injury enrolled from acute inpatient rehabilitation programs between 4 and 16 weeks postinjury.

INTERVENTIONS

Participants were randomized to receive 200 to 400mg of amantadine hydrochloride or placebo daily for 4 weeks, and followed for an additional 2 weeks. Adverse events were recorded and categorized with respect to their nature, timing, and severity.

MAIN OUTCOME MEASURE

Number, type, and severity of medical complications occurring during the 6-week study interval.

RESULTS

A total of 468 medical complications were documented among the patients (.40 events per week per patient). More than 80% of patients experienced at least 1 medical complication, and 41 of these were defined as serious adverse events. New medical complications declined over time in rehabilitation and were not dependent on time since injury. Hypertonia, agitation/aggression, urinary tract infection, and sleep disturbance were the most commonly reported problems. Hydrocephalus, pneumonia, gastrointestinal problems, and paroxysmal sympathetic hyperactivity were the most likely to be severe.

CONCLUSIONS

Patients with DOCs have a high rate of medical complications early after injury. Many of these complications require brain injury expertise for optimal management. Active medical management appears to contribute to the reduction in new complications. An optimal system of care for DOC patients must provide expert medical management in the early weeks after injury.

Glasgow outcome scale at hospital discharge as a prognostic index in patients with severe traumatic brain injury

OBJECTIVE

Evaluate the Glasgow outcome scale (GOS) at discharge (GOS-HD) as a prognostic indicator in patients with traumatic brain injury (TBI).

METHOD

Retrospective data were collected of 45 patients, with Glasgow coma scale <8, age 25±10 years, 36 men, from medical records. Later, at home visit, two measures were scored: GOS-HD (according to information from family members) and GOS LATE (12 months after TBI).

RESULTS

At discharge, the ERG showed: vegetative state (VS) in 2 (4%), severe disability (SD) in 27 (60%), moderate disability (MD) in 15 (33%) and good recovery (GR) in 1 (2%). After 12 months: death in 5 (11%), VS in 1 (2%), SD in 7 (16%), MD in 9 (20%) and GR in 23 (51%). Variables associated with poor outcome were: worse GOS-HD (p=0.03), neurosurgical procedures (p=0.008) and the kind of brain injury (p=0.009).

CONCLUSION

The GOS-HD was indicator of prognosis in patients with severe TBI.

Matrix metalloproteinase 9 and cellular fibronectin plasma concentrations are predictors of the composite endpoint of length of stay and death in the intensive care unit after severe traumatic brain injury

BACKGROUND

The relationship between severe traumatic brain injury (TBI) and blood levels of matrix metalloproteinase-9 (MMP-9) or cellular fibronectin (c-Fn) has never been reported. In this study, we aimed to assess whether plasma concentrations of MMP-9 and c-Fn could have predictive values for the composite endpoint of intensive care unit (ICU) length of stay (LOS) of survivors and mortality after severe TBI. Secondary outcomes were the state of consciousness measured with the Glasgow Coma Scale (GCS) of survivors at 14 days and Glasgow Outcome Scale Extended (GOSE) at 3 months.

METHODS

Forty-nine patients with abbreviated injury scores of the head region ≥ 4 were included. Blood was sampled at 6, 12, 24 and 48 hours after injury. MMP-9 and c-Fn concentrations were measured by ELISA. The values of MMP-9 and c-Fn, and, for comparison, the value of the GCS on the field of the accident (fGCS), as predictors of the composite outcome of ICU LOS and death were assessed by logistic regression.

RESULTS

There was a linear relationship between maximal MMP-9 concentration, measured during the 6-12-hour period, and maximal c-Fn concentration, measured during the 24-48-hour period. The risk of staying longer than 9 days in the ICU or of dying was increased in patients with a maximal early MMP-9 concentration ≥ 21.6 ng/ml (OR = 5.0; 95% CI: 1.3 to 18.6; p = 0.02) or with a maximal late c-Fn concentration ≥ 7.7 μg/ml (OR = 5.4; 95% CI: 1.4 to 20.8; p = 0.01). A similar risk association was observed with fGCS ≤8 (OR, 4.4; 95% CI, 1.2-15.8; p = 0.02). No relationship was observed between MMP-9, c-Fn concentrations or fGCS and the GCS at 14 days of survivors and GOSE at 3 months.

CONCLUSIONS

Plasma MMP-9 and c-Fn concentrations in the first 48 hours after injury are predictive for the composite endpoint of ICU LOS and death after severe TBI but not for consciousness at 14 days and outcome at 3 months.

The effects of brain injury on heart rate variability and the innate immune response in critically ill patients

Brain injury and its related increased intracranial pressure (ICP) may lead to increased vagus nerve activity and the subsequent suppression of innate immunity via the cholinergic anti-inflammatory pathway. This may explain the observed increased susceptibility to infection in these patients. In the present study, we investigated the association between brain injury, vagus nerve activity, and innate immunity. We determined heart rate variability (HRV) as a measure of vagus nerve activity, plasma cytokines, and cytokine production of ex vivo lipopolysaccharide-stimulated whole blood in the first 4 days of admission to the neurological intensive care unit (ICU) in 34 patients with various forms of brain damage. HRV, immune parameters, and the correlations between these measures were analyzed in the entire group of patients and in subgroups of patients with conditions associated with high (intracranial hemorrhage [ICH]) and normal ICP (subarachnoid hemorrhage [SAH] with an extraventricular drain alleviating ICP). Healthy volunteers were used for comparison. HRV total spectral power and ex vivo-stimulated cytokine production were severely depressed in patients compared with healthy volunteers (p<0.05). Furthermore, HRV analysis showed that normalized units of high-frequency power (HFnu, corresponding with vagus nerve activity) was higher, and the low-frequency:high-frequency ratio (LF:HF, corresponding with sympathovagal balance) was lower in patients compared to healthy volunteers (p<0.05). HFnu correlated inversely with ex vivo-stimulated tumor necrosis factor-α (TNF-α) production (r=-0.22, p=0.025). The most pronounced suppression of ex vivo-stimulated cytokine production was observed in the ICH group. Furthermore, in ICH patients, HFnu correlated strongly with lower plasma TNF-α levels (r=-0.73, p=0.002). Our data suggest that brain injury, and especially conditions associated with increased ICP, is associated with vagus nerve-mediated immune suppression.

Coverage policy for neurorehabilitation: an international perspective

BACKGROUND

Coverage policy ultimately determines the delivery of services. This article summarizes the authors' effort to ascertain the extent of publically available information on coverage for neurorehabilitation services internationally.

OBJECTIVE

Present available data on neurorehabilitation coverage and examine the needs for further research in this area.

METHODS

Review of published literature, review of government Web sites, survey of World Federation of NeuroRehabilitation (WFNR) program chairs, and attendees of the 2010 World Congress of NeuroRehabilitation.

RESULTS

A wide variation in coverage was found internationally. Data are not routinely accessible.

CONCLUSIONS

Informed policy requires current data. There is an opportunity for the WFNR to provide leadership in policy for neurorehabilitation services by assembling and maintaining current data on coverage policy internationally.

Hypothermia does not increase the risk of infection: a case control study

Introduction

Hypothermia may improve outcome in patients after traumatic brain injury, especially when hypothermia is maintained for more than 48 hours. In the acute phase, patients with severe brain injury are more vulnerable to infections. Prolonged hypothermic treatment may further enhance the risk of infection. Selective decontamination of the digestive tract (SDD) reduces the risk of respiratory tract infections. The aim of this study was to investigate the incidence of infections in patients treated with hypothermia and normothermia while receiving SDD.

Methods

In this retrospective case control study 35 patients treated with prolonged hypothermia (cases) were identified and 169 patients with severe brain injury were included (controls). Propensity score matching was performed to correct for differences in baseline characteristics and clinical parameters. Primary outcome was the incidence of infection. The secondary endpoints were the micro-organisms found in the surveillance cultures and infection. In addition, a number of clinical characteristics were assessed.

Results

The demographic and clinical data indicated that the cases and controls were well matched. The overall risk of infection during ICU stay was 20% in the hypothermia groups versus 34.4% in the normothermia group (P = 0.388). Pneumonia was diagnosed in 11.4% of patients in both groups (P = 1.000). The incidence of meningitis, wound infection, bacteremia, and urinary tract infection was low and comparable between the groups. SDD surveillance cultures indicated a higher colonization with gram-negative bacteria in the rectal samples of the hypothermia patients.

Conclusions

Hypothermia does not increase the risk of infection in patients treated with SDD.

Brain tissue oxygen monitoring in traumatic brain injury and major trauma: outcome analysis of a brain tissue oxygen-directed therapy

OBJECT

Cerebral ischemia is the leading cause of preventable death in cases of major trauma with severe traumatic brain injury (TBI). Intracranial pressure (ICP) control and cerebral perfusion pressure (CPP) manipulation have significantly reduced the mortality but not the morbidity rate in these patients. In this study, the authors describe their 5-year experience with brain tissue oxygen (PbtO(2)) monitoring, and the effect of a brain tissue oxygen-directed critical care guide (PbtO(2)-CCG) on the 6-month clinical outcome (based on the 6-month Glasgow Outcome Scale score) in patients with TBIs.

METHODS

One hundred thirty-nine patients admitted to Creighton University Medical Center with major traumatic injuries (Injury Severity Scale [ISS] scores >or= 16) and TBI underwent prospective evaluation. All patients were treated with a PbtO(2)-CCG to maintain a brain oxygen level > 20 mm Hg, and control ICP < 20 mm Hg. The role of demographic, clinical, and imaging parameters in the identification of patients at risk for cerebral hypooxygenation and the influence of hypooxygenation on clinical outcome were recorded. Outcomes were compared with those in a historical ICP/CPP patient cohort. Subgroup analysis of severe TBI was performed and compared to data reported in the Traumatic Coma Data Bank.

RESULTS

The majority of injuries were sustained in motor vehicle crashes (63%), and diffuse brain injury was the most common abnormality (58%). Mechanism of injury, severity of TBI, pathological entity, neuroimaging results, and trauma indices were not predictive of ischemia. Factors affecting death included gunshot injury, poor trauma indices, subarachnoid hemorrhage, and coma. After standard resuscitation, 65% of patients had an initially low PbtO(2). Data are presented as means +/- SDs. Treatment with the PbtO(2)-CCG resulted in a 44% improvement in mean PbtO(2) (16.21 +/- 12.30 vs 23.65 +/- 14.40 mm Hg; p < 0.001), control of ICP (mean 12.76 +/- 6.42 mm Hg), and the maintenance of CPP (mean 76.13 +/- 15.37 mm Hg). Persistently low cerebral oxygenation was seen in 37% of patients at 2 hours, 31% at 24 hours, and 18% at 48 hours of treatment. Thus elevated ICP and a persistent low PbtO(2) after 2 hours represented increasing odds of death (OR 14.3 at 48 hours). Survivors and patients with good outcomes generally had significantly higher mean daily PbtO(2) and CPP values compared to nonsurvivors. Polytrauma, associated with higher ISS scores, presented an increased risk of vegetative outcome (OR 9.0). Compared to the ICP/CPP cohort, the mean Glasgow Outcome Scale score at 6 months in patients treated with PbtO(2)-CCG was higher (3.55 +/- 1.75 vs 2.71 +/- 1.65, p < 0.01; OR for good outcome 2.09, 95% CI 1.031-4.24) as was the reduction in mortality rate (25.9 vs 41.50%; relative risk reduction 37%), despite higher ISS scores in the PbtO(2) group (31.6 +/- 13.4 vs 27.1 +/- 8.9; p < 0.05). Subgroup analysis of severe closed TBI revealed a significant relative risk reduction in mortality rate of 37-51% compared with the Traumatic Coma Data Bank data, and an increased OR for good outcome especially in patients with diffuse brain injury without mass lesions (OR 4.9, 95% CI 2.9-8.4).

CONCLUSIONS

The prevention and aggressive treatment of cerebral hypooxygenation and control of ICP with a PbtO(2)-directed protocol reduced the mortality rate after TBI in major trauma, but more importantly, resulted in improved 6-month clinical outcomes over the standard ICP/CPP-directed therapy at the authors' institution.

Traumatic brain injury and forensic neuropsychology

As part of a special issue of The Journal of Head Trauma Rehabilitation, forensic neuropsychology is reviewed as it applies to traumatic brain injury (TBI) and other types of acquired brain injury in which clinical neuropsychologists and rehabilitation psychologists may be asked to render professional opinions about the neurobehavioral effects and outcome of a brain injury. The article introduces and overviews the topic focusing on the process of forensic neuropsychological consultation and practice as it applies to patients with TBI or other types of acquired brain injury. The emphasis is on the application of scientist-practitioner standards as they apply to legal questions about the status of a TBI patient and how best that may be achieved. This article introduces each topic area covered in this special edition.