Patient age and outcome following severe traumatic brain injury: an analysis of 5600 patients

A systematic review of factors contributing to outcomes in patients with traumatic brain injury

AIM AND OBJECTIVE

To review, systematically, factors contributing to outcomes in patients with traumatic brain injury.

BACKGROUND

Traumatic brain injury is a leading cause of death and disability. Several studies have determined the significant predictors of outcomes after traumatic brain injury. The comprehensive identification of these reliable factors for traumatic brain injury is critical to both clinical practice and research.

DESIGN

Systematic literature review.

METHODS

Eligible studies that combined at least two variables to predict outcomes in patient with traumatic brain injury were identified via electronic database searches, footnote chasing and contact with clinical experts. Quality of selected studies was assessed in terms of internal and external validity using 15 questions. Two reviewers independently examined titles, abstracts and whether each met the predefined inclusion criteria.

RESULTS

A total of 46 studies which met review criteria were finally selected. Most studies satisfied internal validity in terms of validity of research variables and multivariate analysis, but few were validated externally. The following factors were significantly associated with unfavourable outcomes: sociodemographic factors such as older age, male gender, lower level of education; clinical factors such as lower Glasgow Coma Scale score, injury caused by motor vehicle crash, hypotension, hypoxia, increased intracranial pressure, no pupil reaction, hypo- or hyperglycaemia, anaemia, coagulopathy, hypo- or hyperthermia, abnormal level of electrolytes, duration of coma; higher level of computed tomography classification by Marshall category; type of intracerebral lesions.

CONCLUSION

Further studies on integrating the sociodemographic factors, the course of the clinical condition and a unified CT scoring system, are recommended for the evaluation and improvement of the prognosis of traumatic brain injury.

RELEVANCE TO CLINICAL PRACTICE

A systematic review of factors contributing to outcome for patients with traumatic brain injury will be invaluable in triage criteria, injury prognostication, care and discharge planning, resource use and patient and family counselling.

Measuring functional and quality of life outcomes following major head injury: common scales and checklists

Traumatic brain injury (TBI) is a major public health issue, which results in significant mortality and long term disability. The profound impact of TBI is not only felt by the individuals who suffer the injury but also their care-givers and society as a whole. Clinicians and researchers require reliable and valid measures of long term outcome not only to truly quantify the burden of TBI and the scale of functional impairment in survivors, but also to allow early appropriate allocation of rehabilitation supports. In addition, clinical trials which aim to improve outcomes in this devastating condition require high quality measures to accurately assess the impact of the interventions being studied. In this article, we review the properties of an ideal measure of outcome in the TBI population. Then, we describe the key components and performance of the measurement tools most commonly used to quantify outcome in clinical studies in TBI. These measurement tools include: the Glasgow Outcome Scale (GOS) and extended Glasgow Outcome Scale (GOSe); Disability Rating Scale (DRS); Functional Independence Measure (FIM); Functional Assessment Measure (FAM); Functional Status Examination (FSE) and the TBI-specific and generic quality of life measures used in TBI patients (SF-36 and SF-12, WHOQOL-BREF, SIP, EQ-5D, EBIQ, and QOLIBRI).

Predictors of neuropsychological improvement following cognitive rehabilitation in patients with gliomas

This study investigated the specific patient factors that predict responsiveness to a cognitive rehabilitation program. The program has previously been demonstrated to be successful at the group level in patients with gliomas, but it is unclear which patient characteristics optimized the effect of the intervention at the individual level. Four categories of possible predictors of improvement were selected for evaluation: sociodemographic and clinical variables, self-reported cognitive symptoms, and objective neuropsychological test performance. Hierarchical logistic regression analyses were conducted, beginning with the most accessible (sociodemographic) variables and ending with the most difficult (baseline neuropsychological) to identify in clinical practice. Nearly 60% of the participants of the intervention were classified as reliably improved. Reliable improvement was predicted by age (p = .003) and education (p = .011). Additional results suggested that younger patients were more likely to benefit specifically from the cognitive rehabilitation program (p = .001), and that higher education was also associated with improvement in the control group (p = .024). The findings are discussed in light of brain reserve theory. A practical implication is that cognitive rehabilitation programs should take the patients' age into account and, if possible, adapt programs to increase the likelihood of improvement among older participants.

The impact of country and culture on end-of-life care for injured patients: results from an international survey

BACKGROUND

Up to 20% of all trauma patients admitted to an intensive care unit die from their injuries. End-of-life decision making is a variable process that involves prognosis, predicted functional outcomes, personal beliefs, institutional resources, societal norms, and clinician experience. The goal of this study was to better understand end-of-life processes after major injury by comparing clinician viewpoints from various countries and cultures.

METHODS

A clinician-based, 38-question international survey was used to characterize the impacts of medical, religious, social, and system factors on end-of-life care after trauma.

RESULTS

A total of 419 clinicians from the United States (49%), Canada (19%), South Africa (11%), Europe (9%), Asia (8%), and Australasia (4%) completed the survey. In America, the admitting surgeon guided most end-of-life decisions (51%), when compared with all other countries (0-27%). The practice structure of American respondents also varied from other regions. Formal medical futility laws are rarely available (14-38%). Ethical consultation services are often accessible (29-98%), but rarely used (0-29%), and typically unhelpful (<30%). End-of-life decision making for patients with traumatic brain injuries varied extensively across regions with regard to the impact of patient age, Glasgow Coma Scale score, and clinician philosophy. Similar differences were observed for spinal cord injuries (age and functional level). The availability and use of "donation after cardiac death" also varied substantially between countries.

CONCLUSIONS

In this unique study, geographic differences in religion, practice composition, decision-maker viewpoint, and institutional resources resulted in significant variation in end-of-life care after injury. These disparities reflect competing concepts (patient autonomy, distributive justice, and religion).

Age-related mitochondrial changes after traumatic brain injury

Mitochondrial dysfunction is known to occur following traumatic brain injury (TBI) and has been well characterized. This study assessed possible age-related changes in the cortical mitochondrial bioenergetics following TBI. Three hours following a moderate TBI, tissue from the ipsilateral hemisphere (site of impact and penumbra) and the corresponding contralateral region were harvested from young (3- to 5-month-old) and aged (22- to 24-month-old) Fischer 344 rats. Synaptic and extrasynaptic mitochondria were isolated using a Ficoll gradient, and several bioenergetic parameters were examined using a Clark-type electrode. Injury-related respiration deficits were observed in both young and aged rats. Synaptic mitochondria showed an age-related decline in the rate of ATP production, and a decline in respiratory control ratios (RCR), which were not apparent in the extrasynaptic fraction. Following respiration analysis, mitochondrial samples were probed for oxidative damage (3-nitrotyrosine [3-NT], 4-hydroxynonenal [4-HNE], and protein carbonyls [PC]). All markers of oxidative damage were elevated with injury and age in the synaptic fraction, but only with injury in the extrasynaptic fraction. Synaptic mitochondria displayed the highest levels of oxidative damage and may contribute to the synaptic bioenergetic deficits seen following injury. Data indicate that cortical synaptic mitochondria appear to have an increased susceptibility to perturbation with age, suggesting that the increased mitochondrial dysfunction observed following injury may impede recovery in aged animals.

Use of an artificial neural network to predict head injury outcome

Object

The authors describe the artificial neural network (ANN) as an innovative and powerful modeling tool that can be increasingly applied to develop predictive models in neurosurgery. They aimed to demonstrate the utility of an ANN in predicting survival following traumatic brain injury and compare its predictive ability with that of regression models and clinicians.

Methods

The authors designed an ANN to predict in-hospital survival following traumatic brain injury. The model was generated with 11 clinical inputs and a single output. Using a subset of the National Trauma Database, the authors “trained” the model to predict outcome by providing the model with patients for whom 11 clinical inputs were paired with known outcomes, which allowed the ANN to “learn” the relevant relationships that predict outcome. The model was tested against actual outcomes in a novel subset of 100 patients derived from the same database. For comparison with traditional forms of modeling, 2 regression models were developed using the same training set and were evaluated on the same testing set. Lastly, the authors used the same 100-patient testing set to evaluate 5 neurosurgery residents and 4 neurosurgery staff physicians on their ability to predict survival on the basis of the same 11 data points that were provided to the ANN. The ANN was compared with the clinicians and the regression models in terms of accuracy, sensitivity, specificity, and discrimination.

Results

Compared with regression models, the ANN was more accurate (p < 0.001), more sensitive (p < 0.001), as specific (p = 0.260), and more discriminating (p < 0.001). There was no difference between the neurosurgery residents and staff physicians, and all clinicians were pooled to compare with the 5 best neural networks. The ANNs were more accurate (p < 0.0001), more sensitive (p < 0.0001), as specific (p = 0.743), and more discriminating (p < 0.0001) than the clinicians.

Conclusions

When given the same limited clinical information, the ANN significantly outperformed regression models and clinicians on multiple performance measures. While this paradigm certainly does not adequately reflect a real clinical scenario, this form of modeling could ultimately serve as a useful clinical decision support tool. As the model evolves to include more complex clinical variables, the performance gap over clinicians and logistic regression models will persist or, ideally, further increase.

Pre-hospital and in-hospital parameters and outcomes in patients with traumatic brain injury: a comparison between German and Australian trauma registries

INTRODUCTION

In Germany, physician-operated emergency medical services (EMS) manage most pre-hospital trauma care. Australia uses a different EMS system, deploying highly trained paramedics for road and air transport of trauma patients. The effect of these different systems on secondary insults to traumatic brain injury (TBI) patients is unclear. There is conflicting evidence regarding which system is preferable. To add to the body of evidence, we compared the profile of injury, pre-hospital management and outcomes of TBI patients from both populations.

METHODS

Cases aged > or = 16 years, with AIS head > or = 3, AIS other body parts < or = 3, recorded in the Victorian State Trauma Registry (VSTR) and Trauma Registry of the German Society of Trauma Surgery (TR-DGU) from 2002 to 2007 were compared.

RESULTS

10,183 cases (5665 German, 4518 Australian) were included. No difference in sex or median age was observed. There were major between-registry differences in type of injury, trauma circumstance, intent and severity of injury. German cases sustained more serious injury and received more pre-hospital interventions. Mortality was significantly higher amongst German patients even when adjusted for demographics, injury severity and in- and pre-hospital parameters. German patients had a longer hospital and ICU stay.

CONCLUSION

There were clear differences in injury characteristics and outcomes in TBI patients between Germany and Australia. As differences in coding, data collection and patient selection are evident, firm conclusions regarding the contribution of variations in pre-hospital care are not possible. The differences in outcome deserve further exploration in prospective studies.

Clinical article: mortality associated with severe head injury in the elderly

BACKGROUND

Age is an important factor in determining prognosis following severe head injury (SHI), although mortality in patients > or =65 years is poorly reported. The aim of this study was to document mortality in patients with SHI > or =65 years.

METHODS

A retrospective analysis of prospectively collected data from the TARN (Trauma Audit and Research Network) database (1996-2004) was performed. Six hundred and sixty-nine patients aged > or =65 with a GCS <9 after a head injury were identified, and mortality at 3 months was recorded.

FINDINGS

Mortality was 71% in 65- to 70-year-old patients (n = 137) (CI, 64-79), 75% for patients aged 70-75 years (n = 147) (CI, 68-82), 85% in patients aged 75-80 years (n = 160) (79-91), and 87% for patients >80 years (n = 225) (CI, 83-91). Mortality for all patients > or =65 years with a GCS 3-5 was >80%. A better outcome was observed in patients with a GCS = 6-8 [65-70 years, 47% (CI, 30-64); 70-75 years, 56% (CI, 43-69); 75-80 years, 73% (CI, 62-85); >80 years, 79% (CI, 70-87)].

CONCLUSIONS

SHI-related mortality continues to increase with age. Overall, these data support a conservative approach to the severely head-injured elderly patient; however, patients presenting with a GCS = 6-8 and below the age of 75 may represent a group where more aggressive therapy may be indicated.

αII-spectrin breakdown products (SBDPs): diagnosis and outcome in severe traumatic brain injury patients

In this study we assessed the clinical utility of quantitative assessments of alphaII-spectrin breakdown products (SBDP145 produced by calpain, and SBDP120 produced by caspase-3) in cerebrospinal fluid (CSF) as markers of brain damage and outcome after severe traumatic brain injury (TBI). We analyzed 40 adult patients with severe TBI (Glasgow Coma Scale [GCS] score 6 ng/mL) and SBDP120 levels (>17.55 ng/mL) strongly predicted death (odds ratio 5.9 for SBDP145, and 18.34 for SBDP120). The time course of SBDPs in nonsurvivors also differed from that of survivors. These results suggest that CSF SBDP levels can predict injury severity and mortality after severe TBI, and can be useful complements to clinical assessment.

Early prognosis in traumatic brain injury: from prophecies to predictions

Traumatic brain injury (TBI) is a heterogeneous condition that encompasses a broad spectrum of disorders. Outcome can be highly variable, particularly in more severely injured patients. Despite the association of many variables with outcome, prognostic predictions are notoriously difficult to make. Multivariable analysis has identified age, clinical severity, CT abnormalities, systemic insults (hypoxia and hypotension), and laboratory variables as relevant factors to include in models to predict outcome in individual patients. Advances in statistical modelling and the availability of large datasets have facilitated the development of prognostic models that have greater performance and generalisability. Two prediction models are currently available, both of which have been developed on large datasets with state-of-the-art methods, and offer new opportunities. We see great potential for their use in clinical practice, research, and policy making, as well as for assessment of the quality of health-care delivery. Continued development, refinement, and validation is advocated, together with assessment of the clinical impact of prediction models, including treatment response.

Aging with traumatic brain injury: cross-sectional follow-up of people receiving inpatient rehabilitation over more than 3 decades

OBJECTIVE

To investigate aging with traumatic brain injury (TBI) by determining if long-term outcomes after TBI are predicted by years postinjury and age at injury after controlling for the severity of the injury and sex.

DESIGN

Cross-sectional follow-up telephone survey.

SETTING

Community residents who had received initial treatment in a comprehensive inpatient rehabilitation hospital.

PARTICIPANTS

Survivors of TBI (N=243) stratified by years postinjury (in seven 5-year cohorts ranging from 1 to over 30 years postinjury) and by age at injury (in 2 cohorts of people injured before or after age 30).

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Measures of postconcussive symptoms, major secondary conditions including fatigue (Modified Fatigue Impact Scale), physical and cognitive activity limitations (FIM, Alertness Behavior Subscale of the Sickness Impact Profile, Medical Outcomes Study 12-Item Health Status Survey Short Form), societal participation restrictions (Craig Handicap Assessment and Reporting Technique), environmental barriers (Craig Hospital Inventory of Environmental Factors), and perceived quality of life (Satisfaction with Life Scale).

RESULTS

Most problems identified by the outcome measures were reported by one fourth to one half of the study participants. Increasing decades postinjury predicted declines in physical and cognitive functioning, declines in societal participation, and increases in contractures. Increasing age at injury predicted declines in functional independence, increases in fatigue, declines in societal participation, and declines in perceived environmental barriers.

CONCLUSIONS

This investigation has increased our understanding of the aging process after TBI by demonstrating that both components of aging (years postinjury and age at injury) are predictive of several outcomes after TBI.

The Relationship between age, injury severity, and MRI findings after traumatic brain injury

Age and injury severity are among the most significant predictors of outcome after traumatic brain injury (TBI). However, only a few studies have investigated the association between, age, injury severity, and the extent of brain damage in TBI. The purpose of this study was to investigate the association between age, measures of injury severity, and brain lesion volumes, as well as viable brain volumes, following TBI. Ninety-eight individuals with mild to very severe TBI (75.5% male, mean age at injury 34.5 years) underwent a structural MRI scan, performed with a 1.5-Tesla machine, on average 2.3 years post-injury. Lesion volumes were highly skewed in their distribution and were dichotomized for statistical purposes. Measures of injury severity were Glasgow Coma Scale score (GCS) and duration of post-traumatic amnesia (PTA). Logistic regression analyses predicting lesion volumes, controlling for participants' gender, cause of injury, time from injury to MRI scan, and total brain volume, revealed that both older age and longer PTA were associated with larger lesion volumes in both grey and white matter in almost all brain regions. Older age was also associated with smaller viable grey matter volumes in most neo-cortical brain regions, while longer PTA was associated with smaller viable white matter volumes in most brain regions. The results suggest that older age worsens the impact of TBI on the brain. They also indicate the validity of duration of PTA as a measure of injury severity that is not just related to one particular injury location.

Meta-analysis of a binary outcome using individual participant data and aggregate data

In this paper, we develop meta-analysis models that synthesize a binary outcome from health-care studies while accounting for participant-level covariates. In particular, we show how to synthesize the observed event-risk across studies while accounting for the within-study association between participant-level covariates and individual event probability. The models are adapted for situations where studies provide individual participant data (IPD), or a mixture of IPD and aggregate data. We show that the availability of IPD is crucial in at least some studies; this allows one to model potentially complex within-study associations and separate them from across-study associations, so as to account for potential ecological bias and study-level confounding. The models can produce pertinent population-level and individual-level results, such as the pooled event-risk and the covariate-specific event probability for an individual. Application is made to 14 studies of traumatic brain injury, where IPD are available for four studies and the six-month mortality risk is synthesized in relation to individual age. The results show that as individual age increases the probability of six-month mortality also increases; further, the models reveal clear evidence of ecological bias, with the mean age in each study additionally influencing an individual's mortality probability. Copyright © 2010 John Wiley & Sons, Ltd.

Ubiquitin C-terminal hydrolase is a novel biomarker in humans for severe traumatic brain injury

OBJECTIVE

Ubiquitin C-terminal hydrolase (UCH-L1), also called neuronal-specific protein gene product (PGP 9.3), is highly abundant in neurons. To assess the reliability of UCH-L1 as a potential biomarker for traumatic brain injury (TBI) this study compared cerebrospinal fluid (CSF) levels of UCH-L1 from adult patients with severe TBI to uninjured controls; and examined the relationship between levels with severity of injury, complications and functional outcome.

DESIGN

This study was designed as prospective case control study.

PATIENTS

This study enrolled 66 patients, 41 with severe TBI, defined by a Glasgow coma scale (GCS) score of < or =8, who underwent intraventricular intracranial pressure monitoring and 25 controls without TBI requiring CSF drainage for other medical reasons.

SETTING

: Two hospital system level I trauma centers.

MEASUREMENTS AND MAIN RESULTS

Ventricular CSF was sampled from each patient at 6, 12, 24, 48, 72, 96, 120, 144, and 168 hrs following TBI and analyzed for UCH-L1. Injury severity was assessed by the GCS score, Marshall Classification on computed tomography and a complicated postinjury course. Mortality was assessed at 6 wks and long-term outcome was assessed using the Glasgow outcome score 6 months after injury. TBI patients had significantly elevated CSF levels of UCH-L1 at each time point after injury compared to uninjured controls. Overall mean levels of UCH-L1 in TBI patients was 44.2 ng/mL (+/-7.9) compared with 2.7 ng/mL (+/-0.7) in controls (p <.001). There were significantly higher levels of UCH-L1 in patients with a lower GCS score at 24 hrs, in those with postinjury complications, in those with 6-wk mortality, and in those with a poor 6-month dichotomized Glasgow outcome score.

CONCLUSIONS

These data suggest that this novel biomarker has the potential to determine injury severity in TBI patients. Further studies are needed to validate these findings in a larger sample.

Prospective meta-analysis using individual patient data in intensive care medicine

Meta-analysis is a technique for combining evidence from multiple trials. However, meta-analyses of studies with substantial heterogeneity among patients within trials-common in intensive care-can lead to incorrect conclusions if performed using aggregate data. Use of individual patient data (IPD) can avoid this concern, increase the power of a meta-analysis, and is useful for exploring subgroup effects. Barriers exist to IPD meta-analysis, most of which are overcome if clinical trials are designed to prospectively facilitate the incorporation of their results with other trials. We review the features of prospective IPD meta-analysis and identify those of relevance to intensive care research. We identify three clinical questions, which are the subject of recent or planned randomised controlled trials where IPD MA offers advantages over approaches using aggregate data.

Age-dependent response of CCAAT/enhancer binding proteins following traumatic brain injury in mice

Exacerbated inflammatory responses have been reported following traumatic injury to the aged brain. The present study was designed to investigate the involvement of the transcription factors belonging to the CCAAT/enhancer binding protein (C/EBP) family that regulate expression of many of the pro-inflammatory genes which show increased expression following injury to the aged brain. Controlled cortical impact injury was induced in adult (5-6 months) and aged (22-24 months) C57/BL6 mice. C/EBP mRNA and protein expression were analyzed in injured cortex at 1, 3, and 7 days post-injury. Expression of C/EBPalpha was reduced relative to baseline at day 1 in both adult and aged mice, whereas, it increased at days 3 and 7 post-injury. No significant differences were observed between adult and aged brain. Upregulation of C/EBPbeta was observed 1 day following injury in both the adult and aged brain, but there were no major age-related differences in mRNA levels. However, there was higher C/EBPbeta protein in the aged brain. C/EBPdelta expression increased beginning 1 day post-injury in both adult and aged brain. In this case, the increase in C/EBPdelta expression was higher in the aged brain than in the adult at all time points studied. Expression of CCAAT/enhancer binding protein homologous protein (CHOP), a transcription factor involved in ER stress and protein unfolding responses, was also up-regulated in response to injury, but CHOP levels were significantly lower in the aged than the adult brain. Based on these results, we conclude that differential expression of C/EBP beta, delta and CHOP might contribute to the hyper-inflammatory response and poor prognosis following traumatic brain injury in the elderly patients. In addition elevated C/EBPdelta levels following TBI in the aged brain may play a role in the link between TBI and Alzheimer's disease.

Functional outcome is impaired following traumatic brain injury in aging Nogo-A/B-deficient mice

Increasing age is associated with a poor prognosis following traumatic brain injury (TBI). CNS axons may recover poorly following TBI due to expression of myelin-derived inhibitors to axonal outgrowth such as Nogo-A. To study the role of Nogo-A/B in the pathophysiological response of the elderly to TBI, 1-year-old mice deficient in Nogo-A/B (Nogo-A/B homozygous(-/-) mice), Nogo-A/B heterozygous(-/+) mice, and age-matched wild-type (WT) littermate controls were subjected to a controlled cortical impact (CCI) TBI. Sham-injured WT mice (7 months old) and 12 month old naïve Nogo-A/B(-/-) and Nogo-A/B(-/+) served as controls. Neurological motor function was evaluated up to 3 weeks, and cognitive function, hemispheric tissue loss, myelin staining and hippocampal beta-amyloid (A beta) immunohistochemistry were evaluated at 4 weeks post-injury. In WT littermates, TBI significantly impaired learning ability at 4 weeks and neurological motor function up to 2 weeks post-injury and caused a significant loss of hemispheric tissue. Following TBI, Nogo-A/B(-/-) mice showed significantly less recovery from neurological motor and cognitive deficits compared to brain-injured WT mice. Naïve Nogo-A/B(-/-) and Nogo-A/B(-/+) mice quickly learned the MWM task in contrast to brain-injured Nogo-A/B(-/-) mice who failed to learn the MWM task at 4 weeks post-injury. Hemispheric tissue loss and cortical lesion volume were similar among the brain-injured genotypes. Neither TBI nor the absence of NogoA/B caused an increased A beta expression. Myelin staining showed a reduced area and density in the corpus callosum in brain-injured Nogo-A/B(-/-) animals compared to their littermate controls. These novel and unexpected behavioral results demonstrate that the absence of Nogo-A/B may negatively influence outcome, possibly related to hypomyelination, following TBI in mice and suggest a complex role for this myelin-associated axonal growth inhibitor following TBI.

Older people and major trauma

Major traumatic injury is a leading cause of death in younger age groups, but increasingly older people are affected also. Adverse outcomes, both physical and psychological, are associated with injury in the older population. This review aims to locate and describe the evidence relating to older people and major trauma in order to inform policy, practice, research and education. The published research and systematic reviews fall into three main topics: mechanism of traumatic injury in older people, the effects of co-morbidities on older trauma patients and outcomes following serious traumatic injury in older people. The psychological impact of traumatic injury and the resulting functional alteration cannot be underestimated in this group of patients.

The acute inflammatory response in trauma / hemorrhage and traumatic brain injury: current state and emerging prospects

Traumatic injury/hemorrhagic shock (T/HS) elicits an acute inflammatory response that may result in death. Inflammation describes a coordinated series of molecular, cellular, tissue, organ, and systemic responses that drive the pathology of various diseases including T/HS and traumatic brain injury (TBI). Inflammation is a finely tuned, dynamic, highly-regulated process that is not inherently detrimental, but rather required for immune surveillance, optimal post-injury tissue repair, and regeneration. The inflammatory response is driven by cytokines and chemokines and is partially propagated by damaged tissue-derived products (Damage-associated Molecular Patterns; DAMP's). DAMPs perpetuate inflammation through the release of pro-inflammatory cytokines, but may also inhibit anti-inflammatory cytokines. Various animal models of T/HS in mice, rats, pigs, dogs, and non-human primates have been utilized in an attempt to move from bench to bedside. Novel approaches, including those from the field of systems biology, may yield therapeutic breakthroughs in T/HS and TBI in the near future.

Predictors of in-hospital mortality and 6-month functional outcomes in older adults after moderate to severe traumatic brain injury

INTRODUCTION

Traumatic brain injury (TBI) is the single largest cause of death and disability following injury worldwide. While TBI in older adults is less common, it still contributes to significant morbidity and mortality in this group. Understanding the patient characteristics that result in good and poor outcome after TBI is important in the clinical management and prognosis of older adult TBI patients. This population-based study investigated predictors of mortality and longer term functional outcomes following serious TBI in older adults.

METHODS

All older adults (aged>64 years), isolated moderate to severe TBI cases from the population-based Victorian State Trauma Registry for the period July 2005 to June 2007 (inclusive) were extracted for analysis. Demographic, injury event, injury diagnosis, management and comorbid status information were obtained and the outcomes of interest were in-hospital mortality, and the Glasgow Outcome Scale-Extended (GOS-E) score at 6 months post-injury. Multivariate logistic regression analyses were used to identify independent predictors of in-hospital mortality and independent living (GOS-E>4) status at 6 months.

RESULTS

Of the 428 isolated, older adult TBI cases, the majority were the result of a fall (88%), male (55%), and aged>74 years (76%). The in-hospital death rate was 28% and increasing age (p=0.009), decreasing GCS (p<0.001) and injury type (p=0.002) were significant independent predictors of in-hospital mortality. Of the 310 patients who survived to discharge, 65% were successfully followed-up 6 months following injury. There was no difference between patients lost to follow-up and those successfully followed-up with respect to the key population indicators of age, gender, or head injury severity. Younger (<75 years) patients, and those with an SBP on arrival at hospital of 131-150mmHg, were at increased odds of living independently at follow-up. No patients with a GCS<9 had a good 6-month outcome, and most of them died. The survival rate for brainstem injury was also low (21%).

CONCLUSION

In this population-based study, we found that age, GCS, brainstem injury, and systolic blood pressure were the most important factors in predicting outcome in older adults with an isolated moderate to severe TBI.

Clinical evaluation of the safety and efficacy of lumbar cerebrospinal fluid drainage for the treatment of refractory increased intracranial pressure

OBJECT

Several approaches have been established for the treatment of intracranial hypertension; however, a considerable number of patients remain unresponsive to even aggressive therapeutic strategies. Lumbar CSF drainage has been contraindicated in the setting of increased intracranial pressure (ICP) because of possible cerebral herniation. The authors of this study investigated the efficacy and safety of controlled lumbar CSF drainage in patients suffering from intracranial hypertension following severe traumatic brain injury (TBI) or aneurysmal subarachnoid hemorrhage (SAH).

METHODS

The authors prospectively evaluated 100 patients-45 with TBI and 55 with SAH-having a mean age of 43.7 +/- 15.7 years (mean +/- SD) and suffering from refractory intracranial hypertension (ICP > 20 mm Hg). Intracranial pressure and cerebral perfusion pressure (CPP) before and after the initiation of lumbar CSF drainage as well as related complications were documented. Patient outcomes were assessed 6 months after injury.

RESULTS

The application of lumbar CSF drainage led to a significant reduction in ICP from 32.7 +/- 10.9 to 13.4 +/- 5.9 mm Hg (p < 0.05) and an increase in CPP from 70.6 +/- 18.2 to 86.2 +/- 15.4 mm Hg (p < 0.05). Cerebral herniation with a lethal outcome occurred in 6% of patients. Thirty-six patients had a favorable outcome, 12 were severely disabled, 7 remained in a persistent vegetative state, and 45 died.

CONCLUSIONS

Lumbar drainage of CSF led to a significant and clinically relevant reduction in ICP. The risk of cerebral herniation can be minimized by performing lumbar drainage only in cases with discernible basal cisterns.

Clinical and neuroimaging features of severely brain-injured patients treated in a neurosurgical unit compared with patients treated in peripheral non-neurosurgical hospitals

Most European TBI patients are managed in peripheral hospitals without benefit of guidelines for transfer of such patients to neurosurgical units as needed. This report compares clinical features and outcomes in two series of severe TBI patients: those admitted to a neurosurgical centre or to a general hospital, all in the Piedmont Region of Italy. Of 630 patients with a GCS of 3-8, 351 were admitted to a centralized neurosurgical unit, and 279 were admitted and treated at a peripheral hospital. All patients had a CT scan read by a neurosurgeon on duty and were classified using the Marshall criteria as having a diffuse injury or non-surgical mass lesions. Outcomes were assessed between 6 months and 6 years using either the GOS Extended or the GOS. Independent variables were age, sex, GCS score and Marshall classification. All the examined factors were significantly different between the two groups (p<0.001). For patients admitted to the neurosurgical centre, age, Marshall classification of the CT and GCS were predictors of a favourable outcome, while for patients treated in general hospitals, Marshall classification of the CT, gender and age were predictors of a favourable outcome. Patients admitted to neurosurgical centres are different from those treated in general hospitals not having these specialized facilities and personnel. The absence of guidelines for the transfer of these patients for more advanced care are lacking and should be the focus of new studies on patient referral.

Evaluation of models that predict short-term outcome after traumatic brain injury

PRIMARY OBJECTIVE

This study aimed to identify models that predicted the short-term outcome after traumatic brain injury (TBI) from the literature and to evaluate their clinical significance.

METHODS

Literatures from PubMED were reviewed. Regression coefficients and intercepts were extracted. A group of 229 cases was used for validation and the unfavourable rate was calculated to assess the validity of these models by the area under receiver operating. Characteristic curve (AUC), C-statistic and Brier score.

MAIN RESULTS

In total, 13 studies of 18 different models were included. Data from the validation group were in accordance with the indicators of the studies reviewed. All models got an AUC value ranging from 0.644-0.890 except two (AUC value <0.6) and their Brier scores were near zero. However, the calibration of most studies was insufficient (p < 0.05).

CONCLUSIONS

Most of the models included in this study have a good discriminatory power while lacking sufficient calibration. However, they all predict with relative accuracy at the level of individuals. Therefore, current models can be used to predict the survival rate of individual patients and may be useful to inform patients and relatives about the likelihood of a beneficial outcome.

Prediction of the level of cognitive functional independence in acute care following traumatic brain injury

PRIMARY OBJECTIVE

To determine a predictive model for cognitive functional outcome of patients with traumatic brain injury (TBI) at discharge from acute care.

METHODS AND PROCEDURE

Three hundred and thirty-five patients were included in this analysis. Variables considered were age, education, initial score on the Glasgow Coma Scale (GCS), duration of post-traumatic amnesia (PTA), cerebral imaging results and the need for neurosurgical intervention.

EXPERIMENTAL INTERVENTIONS

Functional Independence Measure (FIM).

MAIN OUTCOMES AND RESULTS

Results of this analysis indicated better cognitive FIM at discharge from acute care settings for patients with TBI when PTA was less than 24 hours, when level of education was higher, when no parietal lesion was identified, when no neurosurgical intervention was required, for patients with TBI who were younger and who presented with a higher GCS score upon admission.

CONCLUSIONS

This model will help to plan resource allocation for treatment and discharge planning within the first weeks following TBI.

The epidemiology of severe traumatic brain injury among persons 65 years of age and older in Oklahoma, 1992–2003

PRIMARY OBJECTIVE

To describe the epidemiology of traumatic brain injury (TBI) among persons 65 years of age and older in Oklahoma from 1992-2003.

RESEARCH DESIGN

Descriptive epidemiology of data collected through active statewide surveillance on TBI inpatient hospitalizations and fatalities.

METHODS AND PROCEDURES

Data collected from hospital medical records and the Office of the Chief Medical Examiner. TBI was defined by ICD-9-CM codes for skull fracture 800.0-801.9, 803.0-804.9, concussion or other intracranial injury 850.0-854.1 and head injury, unspecified 959.01; all cases included a description of TBI.

MAIN OUTCOME AND RESULTS

TBI rates increased 79% for the study population; however, case-fatality rates decreased from 32% in 1992 to 18% in 2003. The TBI rate increase was observed among all elderly age groups, both genders and all races. Unintentional injuries nearly doubled while both assault and self-inflicted injuries decreased. Fall-related TBI increased by 126%, while MVC-related TBI increased by 17%. Survivors were hospitalized for an average of 6.8 days and over half required post-acute care.

CONCLUSIONS

The increased TBI rate and decreased case-fatality rate among elderly persons means potentially more persons living with TBI disability. TBI prevention efforts among the elderly must be expanded, especially for fall-related TBI.

Management and outcome of patients with acute traumatic subdural hematomas and pre-injury oral anticoagulation therapy

BACKGROUND

Acute subdural hematomas (aSDHs) are found in up to one-third of patients with severe traumatic brain injury and are associated with an unfavorable outcome in the majority of cases. Mortality ranges between 40 and 60%, but was reported to be even higher in patients undergoing oral anticoagulation therapy (OAT) at the time of injury. The objective of this study is to specifically report on the peri-operative management and outcome of patients with aSDH and pre-injury OAT.

MATERIAL AND METHODS

From June 2002 to June 2006, all patients with OAT who underwent surgical treatment of aSDH were retrospectively analysed. Results of pre-operative blood tests, the peri-operative and surgical management and the clinical courses were assessed. Patient outcome is reported according to the Glasgow Outcome Scale (GOS) at 6 months.

RESULTS

Eleven (10.3%) out of 107 patients with aSDH were on OAT. Patients with OAT were significantly older than patients without OAT (72.4 +/- 9.3 versus 59.9 +/- 17.5 years; p<0.05, Mann-Whitney U-test). Intensity of head trauma was moderate in four and severe in seven patients with a median pre-operative Glasgow Coma Scale (GCS) of 8. Median pre-treatment prothrombin time and international normalized ratio were 23% (range: 10-65%) and 3.3 (range: 1.5-10.6), respectively. Replacement therapy consisted of administration of prothrombin complex concentrates, vitamin K and FFP (fresh frozen plasma). In four patients, antithrombin was additionally given to prevent disseminated intravascular coagulation. Surgical treatment consisted of craniotomy (n=10) or craniectomy (n=1) and hematoma evacuation with intracranial pressure probe placement. Low molecular weight heparin was administered as pharmacological prophylaxis of thrombembolic events in an increasing dose post-operatively. At 6 months, six out of 11 patients survived with a median GOS of 4. All-cause mortality was 45.5%. A pre-operative GCS of < or = 8 was not associated with an increased risk of mortality (p>0.5, Fisher's exact test). No relevant rebleedings or thrombembolic complications were observed. The mortality rate of patients who did not undergo OAT was 50%.

CONCLUSION

A large number of patients with aSDH are on pre-injury OAT. Specific replacement therapy facilitates successful clot evacuation without bleeding complications. The overall outcome of these patients does not seem to differ from historical cohorts with aSDH without OAT, but a large prospective multicenter study is warranted to answer that question.

Can we improve neurological outcomes in severe traumatic brain injury? Something old (early prophylactic hypothermia) and something new (erythropoietin)

Traumatic brain injury is a leading cause of mortality and long-term morbidity, particularly affecting young people. With our best therapies, one half of the patients with severe traumatic brain injury are never capable of living independently. Two interventions, which have real potential to improve neurological outcomes in patients with traumatic brain injury, are (i) very early induction of prophylactic hypothermia and (ii) exogenous erythropoietin therapy. There is substantial experimental evidence, a plausible biological rationale, and supportive clinical evidence from clinical trials to suggest a possible beneficial effect of prophylactic hypothermia and also for exogenous erythropoietin therapy in severe traumatic brain injury. Despite the recent guidelines and publications recommending these interventions, critical care clinicians should be conservative towards implementing these therapies outside clinical trials due to substantial efficacy and safety concerns. Nevertheless the high morbidity and mortality associated with severe traumatic brain injury (TBI) demands that we investigate the safety and efficacy of these promising potential therapies as a matter of urgency.

The role of MR imaging in assessing prognosis after severe and moderate head injury

PURPOSE

The objective of this work is two-fold: to determine the role of MRI findings in establishing the prognosis of patients with moderate and severe traumatic brain injury (TBI) admitted to our centre, measured with different outcome scales; and to determine in which patients the information given by MR findings adds prognostic information to that from traditional prognostic factors.

METHODS

One hundred patients suffering moderate or severe head injury in whom MRI had been performed in the first 30 days after trauma were included. The MRI was evaluated by two neuroradiologists who were not aware of the initial CT results or the clinical situation of the patients. Outcome was determined 6 months after head injury by means of the extended version of the Glasgow Outcome Scale. The prognostic capacity of the different factors related to outcome was compared by the analysis of receiver operating characteristic (ROC) curves and the area under the curve (AUC) for each factor.

RESULTS

There exists a clear relation between the depth of the traumatic lesions shown on MRI, and their classification by the proposed scale, and the outcome of patients suffering traumatic brain injury determined by different scales 6 months after injury.

CONCLUSIONS

The anatomical substrate of TBI depicted by MRI could be a useful prognostic tool in patients suffering moderate and severe head injury. Patients with a score of 4 or less on the motor subscale of the GCS scale are those who could benefit most from the prognostic information provided by MRI.

Risk Factors Predicting Unfavorable Neurological Outcome during the Early Period after Traumatic Brain Injury

OBJECTIVE

We aimed to identify clinico-radiological risk factors that may predict unfavorable neurological outcomes in traumatic brain injury (TBI), and to establish a guideline for patient selection in clinical trials that would improve neurological outcome during the early post TBI period.

METHODS

Initial clinico-radiological data of 115 TBI patients were collected prospectively. Regular neurological assessment after standard treatment divided the above patients into 2 groups after 6 months : the Favorable neurological outcome group (GOS : good & moderate disability, DRS : 0-6, LCFS : 8-10) and the Unfavorable group (GOS : severe disability-death, DRS : 7-29 and death, LCFS : 1-7 and death).

RESULTS

There was a higher incidence of age >/=35 years, low initial GCS score, at least unilateral pupil dilatation, and neurological deficit in the Unfavorable group. The presence of bilateral parenchymal lesions or lesions involving the midline structures in the initial brain CT was observed to be a radiological risk factor for unfavorable outcome. Multivariate analysis demonstrated that age and initial GCS score were independent risk factors. The majority of the Favorable group patients with at least one or more risk factors showed improvement of GCS scores within 2 months after TBI.

CONCLUSION

Patients with the above mentioned clinico-radiological risk factors who received standard treatment, but did not demonstrate neurological improvement within 2 months after TBI were deemed at risk for unfavorable outcome. These patients may be eligible candidates for clinical trials that would improve functional outcome after TBI.

[Influence of age, gender, and severity on recovery of patients with brain injury]

PURPOSE

This study was conducted to investigate the individual and cross influences of age, gender, and severity on recovery of patients with brain injury.

METHODS

For the purpose of the study, traumatic or spontaneous brain injury patients admitted to the intensive care unit (ICU) were conveniently selected. The data regarding outcomes were collected 3 months after admission.

RESULTS

Individual influences of the study variables on patients' recovery were significant, except for gender. But while the individual influence of gender on recovery was not significant, cross influence of gender and age was significant, but only for the sub-dimension of 'arousalbility and awareness'. The study results also showed that 3-way cross influence of gender, age, and severity was only significant on the sub-dimension of 'arousalbility and awareness'.

CONCLUSION

The sub-dimension of recovery cross influenced by the demographic factors of gender and age, and severity was 'arousalbility and awareness'. This might indicate that the study variables that cross influencing recovery had more influence on consciousness compared to physical function and psycho-social adaptation.

The effect of the introduction of the Amsterdam Trauma Workflow Concept on mortality and functional outcome of patients with severe traumatic brain injury

The purpose of this study was to analyze the effect of the introduction of an all-in workflow concept that included direct computed tomography (CT) scanning in the trauma room on mortality and functional outcome of trauma patients with severe traumatic brain injury (TBI) admitted to a level-1 trauma center. To this end, a retrospective comparison was made of a 1-year cohort prior to the implementation of the all-in workflow concept (Pre-CT in trauma room cohort [Pre-TRCT]) and a 1-year cohort after the implementation (Post-TRCT). All severely injured TBI patients aged 16 years or older that were presented in our level-1 trauma center and that underwent a CT of the head were initially included. Severe TBI was defined as an Abbreviated Injury Scale (AIS) score of >2 of the head region following trauma. Primary outcome parameter was TBI-related mortality during primary hospital admission. Secondary outcome parameter was the functional outcome based on GOS-Extended. A total of 59 patients were included in the Pre-TRCT and 49 in the Post-TRCT. Median age was 49 years in the Post-TRCT and 44 years in the Pre-TRCT (not significant [NS]). Median ISS was similar (ISS = 25). Median Head-AIS was higher in the Post-TRCT (5 vs. 4, NS). Initial CT scanning was completed faster in the Post-TRCT. There was a significant difference of 23% mortality in favor of the Post-TRCT for TBI-related mortality during primary hospital admission (p < 0.05). For acute neurosurgical interventions, time until intervention tended to be faster in the Post-TRCT (NS). Functional outcomes for survivors were higher in the Post-TRCT (6 vs. 5, NS).

Cognitive and functional outcomes of terror victims who suffered from traumatic brain injury

PRIMARY OBJECTIVE

To describe the outcomes of terror victims suffered from traumatic brain injury (TBI).

RESEARCH DESIGN

Retrospective chart review of 17 terror and 39 non-terror TBI patients treated in a rehabilitation department during the same period.

METHODS AND PROCEDURE

Variables include demographic data, Injury Severity Scale (ISS), length of stay (LOS) and imaging results. ADL was measured using the Functional Independence Measurement (FIM), cognitive and memory functions were measured using the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) battery and the Rivermead Battery Memory Test (RBMT), respectively.

MAIN OUTCOME AND RESULTS

Terror TBI patients were significantly younger, had higher ISS score and higher rates of intracerebral haemorrhage (ICH), brain surgery and penetrating brain injuries than the non-terror TBI group. There was no difference in mean LOS, mean FIM values, mean FIM gain and mean cognitive and memory improvement between groups. Terror victims suffered from a higher percentage of post-traumatic epilepsy (35% vs. 10%, p=0.05), whereas the rate of PTSD and the rate of return to previous occupation were similar between groups.

CONCLUSIONS

Although TBI terror victims had more severe injury, they gained most of ADL functions and their rehabilitation outcomes were similar to non-terror TBI patients. These favourable results were achieved due to a comprehensive interdisciplinary approach to terror victims and also by national support which allowed an adequate period of treatment and sufficient resources as needed.

Anticoagulation and the elderly head trauma patient

We sought to determine the effect of anticoagulation therapy on outcomes in elderly patients with closed head injury. We retrospectively reviewed elderly closed head injury patients (> or = 65 years) comparing 52 patients on warfarin (AC) with 439 patients not on warfarin (NAC) with subsequent 1:3 propensity matching used to analyze comparable groups. The overall AC group had a higher head abbreviated injury score (AIS) (4.0 +/- 0.7 vs 3.8 +/- 0.7, P = 0.04) compared with the NAC group. After propensity matching, 49 AC patients were compared with 147 NAC patients who were similar for age, gender, injury severity score, and head AIS. Admission INR was higher in the AC group compared to the NAC group (2.5 +/- 1.3 vs 1.1 +/- 0.3, P < 0.0001) and the AC group had a higher mortality rate (38.8% AC (19/49) vs 23.1% NAC (34/147), P = 0.04). In the AC group, survivors and nonsurvivors had similar repeat International Normalized Ratio (INR) values (1.57 +/- 0.65 survivors vs 1.8 +/- 0.72 nonsurvivors, P = 0.31). The AC group experienced greater morbidity after trauma and had higher mortality rates than their NAC counterparts. Prevention of injury and more selective use of warfarin in this patient population are essential to decrease mortality.

Exacerbated glial response in the aged mouse hippocampus following controlled cortical impact injury

Old age is associated with enhanced susceptibility to and poor recovery from brain injury. An exacerbated microglial and astrocyte response to brain injury might be involved in poor outcomes observed in the elderly. The present study was therefore designed to quantitate the expression of markers of microglia and astrocyte activation using real-time RT-PCR, immunoblot and immunohistochemical analysis in aging brain in response to brain injury. We examined the hippocampus, a region that undergoes secondary neuron death, in aged (21-24 months) and adult (5-6 months) mice following controlled cortical impact (CCI) injury to the sensorimotor cortex. Basal mRNA expression of CD11b and Iba1, markers of activated microglia, was higher in aged hippocampus as compared to the adult. The mRNA expression of microglial markers increased and reached maximum 3 days post-injury in both adult and aged mice, but was higher in the aged mice at all time points studied, and in the aged mice the return to baseline levels was delayed. Basal mRNA expression of GFAP and S100B, markers of activated astrocytes, was higher in aged mice. Both markers increased and reached maximum 7 days post-injury. The mRNA expression of astrocyte markers returned to near basal levels rapidly after injury in the adult mice, whereas again in the aged mice return to baseline was delayed. Immunochemical analysis using Iba1 and GFAP antibodies indicated accentuated glial responses in the aged hippocampus after injury. The pronounced and prolonged activation of microglia and astrocytes in hippocampus may contribute to worse cognitive outcomes in the elderly following TBI.

A systematic review finds methodological improvements necessary for prognostic models in determining traumatic brain injury outcomes

OBJECTIVES

To describe the modeling techniques used for early prediction of outcome in traumatic brain injury (TBI) and to identify aspects for potential improvements.

STUDY DESIGN AND SETTING

We reviewed key methodological aspects of studies published between 1970 and 2005 that proposed a prognostic model for the Glasgow Outcome Scale of TBI based on admission data.

RESULTS

We included 31 papers. Twenty-four were single-center studies, and 22 reported on fewer than 500 patients. The median of the number of initially considered predictors was eight, and on average five of these were selected for the prognostic model, generally including age, Glasgow Coma Score (or only motor score), and pupillary reactivity. The most common statistical technique was logistic regression with stepwise selection of predictors. Model performance was often quantified by accuracy rate rather than by more appropriate measures such as the area under the receiver-operating characteristic curve. Model validity was addressed in 15 studies, but mostly used a simple split-sample approach, and external validation was performed in only four studies.

CONCLUSION

Although most models agree on the three most important predictors, many were developed on small sample sizes within single centers and hence lack generalizability. Modeling strategies have to be improved, and include external validation.

Traumatic brain injury: can the consequences be stopped?

Traumatic brain injury is a leading cause of morbidity and death in both industrialized and developing countries. To date, there is no targeted pharmacological treatment that effectively limits the progression of secondary injury. The delayed progression of deterioration of grey and white matter gives hope that a meaningful intervention can be applied in a realistic timeframe following initial trauma. In this review we discuss new insights into the subcellular mechanisms of secondary injury that have highlighted numerous potential targets for intervention.