Epidemiology of severe brain injuries: a prospective population-based study

Relevance of gap junctions and large pore channels in traumatic brain injury

In case of traumatic brain injury (TBI), occurrence of central nervous tissue damage is frequently aligned with local modulations of neuronal and glial gap junction channel expression levels. The degree of gap junctional protein expression and intercellular coupling efficiency, as well as hemichannel function has substantially impact on the course of trauma recovery and outcome. During TBI, gap junctions are especially involved in the intercellular molecule trafficking on repair of blood vessels and the regulation of vasomotor tone. Furthermore, gliosis and astrocytic swelling due to mechanical strain injury point out the consequences of derailed gap junction communication. This review addresses the outstanding role of gap junction channels in TBI pathophysiology and links the current state of results to applied clinical procedures as well as perspectives in acute and long-term treatment options.

Inhibition of the membrane attack complex of the complement system reduces secondary neuroaxonal loss and promotes neurologic recovery after traumatic brain injury in mice

Traumatic brain injury (TBI) is the leading cause of disability and death in young adults. The secondary neuroinflammation and neuronal damage that follows the primary mechanical injury is an important cause of disability in affected people. The membrane attack complex (MAC) of the complement system is detected in the traumatized brain early after TBI; however, its role in the pathology and neurologic outcome of TBI has not yet been investigated. We generated a C6 antisense oligonucleotide that blocks MAC formation by inhibiting C6, and we compared its therapeutic effect to that of Ornithodoros moubata complement inhibitor (OmCI), a known inhibitor of C5 activation that blocks generation of the anaphylatoxin C5a and C5b, an essential component of MAC. Severe closed head injury in mice induced abundant MAC deposition in the brain. Treatment with C6 antisense reduced C6 synthesis (85%) and serum levels (90%), and inhibited MAC deposition in the injured brain (91-96%). Treatment also reduced accumulation of microglia/macrophages (50-88%), neuronal apoptosis, axonal loss and weight loss (54-93%), and enhanced neurologic performance (84-92%) compared with placebo-treated controls after injury. These data provide the first evidence, to our knowledge, that inhibition of MAC formation in otherwise complement-sufficient animals reduces neuropathology and promotes neurologic recovery after TBI. Given the importance of maintaining a functional complement opsonization system to fight infections, a critical complication in TBI patients, inhibition of the MAC should be considered to reduce posttraumatic neurologic damage. This work identifies a novel therapeutic target for TBI and will guide the development of new therapy for patients.

Severe traumatic brain injury in a high-income country: an epidemiological study

This adult cohort determined the incidence and patients' short-term outcomes of severe traumatic brain injury (sTBI) in Switzerland and age-related differences. A prospective cohort study with a follow-up at 14 days was performed. Patients ≥16 years of age sustaining sTBI and admitted to 1 of 11 trauma centers were included. sTBI was defined by an Abbreviated Injury Scale of the head (HAIS) score >3. The centers participated from 6 months to 3 years. The results are presented as percentages, medians, and interquartile ranges (IQRs). Subgroup analyses were performed for patients ≤65 years (younger) and >65 (elderly). sTBI was observed in 921 patients (median age, 55 years; IQR, 33-71); 683 (74.2%) were male. Females were older (median age, 67 years; IQR, 42-80) than males (52; IQR, 31-67; p<0.00001). The estimated incidence was 10.58 per 100,000 inhabitants per year. Blunt trauma was observed in 879 patients (95.4%) and multiple trauma in 283 (30.7%). Median Glasgow Coma Score (GCS) on the scene was 9 (IQR 4-14; 8 in younger, 12 in elderly) and in emergency departments 5 (IQR, 3-14; 3 in younger, 8 in elderly). Trauma mechanisms included the following: 484 patients with falls (52.6%; younger, 242 patients [50.0%]; elderly, 242 [50.0%]), 291 with road traffic accidents (31.6%; younger, 237 patients [81.4%]; elderly, 54 [18.6%]), and 146 with others (15.8%). Mortality was 30.2% (24.5% in younger, 40.9% in elderly). Median GCS at 14 days was 15 (IQR, 14-15) without differences among subgroups. Estimated incidence of sTBI in Switzerland was low, age was high, and mortality considerable. The elderly had higher initial GCS and a higher death rate, but high GCS at 14 days.

The effectiveness of selected Tai Chi exercises in a program of strategic rehabilitation aimed at improving the self-care skills of patients aroused from prolonged coma after severe TBI

Background

Difficulties in self-care constitute a very common problem for patients recovering from prolonged coma after a severe TBI, and a major factor reducing their quality of life. Effective new rehabilitation programs that would help solve this problem are urgently needed. The purpose of our experiment was to evaluate improvement in this respect in a group of patients aroused from prolonged coma who participated in a goal-oriented rehabilitation program (Rehab-3), enhanced with selected elements of Tai-Chi.

Material/Methods

We examined 40 patients aroused from prolonged coma after a severe TBI, undergoing long-term rehabilitation according to a standard phased rehabilitation program. These patients were divided into two numerically even groups: a control group treated according to the standard program, and an experimental group, who received an additional goal oriented program enhanced with selected Tai-Chi exercises. The research methods included analysis of documentation (MRI, CT), a structured clinical interview, and the Standard Self-Care Scale.

Results

The experimental group achieved significant improvement of self-care skills, whereas in the control group the improvement was slight and not statistically significant. The value of co-efficient j (0.64) indicates a very strong association between the rehabilitation procedure and improved self-care in the experimental group, but not in the control group.

Conclusions

Our results confirmed that a goal-oriented rehabilitation program enhanced with elements of Tai-Chi was more effective than the standard program in improving the performance of activities of daily living.

Towards clinical management of traumatic brain injury: a review of models and mechanisms from a biomechanical perspective

Traumatic brain injury (TBI) is a major worldwide healthcare problem. Despite promising outcomes from many preclinical studies, the failure of several clinical studies to identify effective therapeutic and pharmacological approaches for TBI suggests that methods to improve the translational potential of preclinical studies are highly desirable. Rodent models of TBI are increasingly in demand for preclinical research, particularly for closed head injury (CHI), which mimics the most common type of TBI observed clinically. Although seemingly simple to establish, CHI models are particularly prone to experimental variability. Promisingly, bioengineering-oriented research has advanced our understanding of the nature of the mechanical forces and resulting head and brain motion during TBI. However, many neuroscience-oriented laboratories lack guidance with respect to fundamental biomechanical principles of TBI. Here, we review key historical and current literature that is relevant to the investigation of TBI from clinical, physiological and biomechanical perspectives, and comment on how the current challenges associated with rodent TBI models, particularly those involving CHI, could be improved.

Factors associated with the withdrawal of life-sustaining therapies in patients with severe traumatic brain injury: a multicenter cohort study

PURPOSE

To identify factors associated with decisions to withdraw life-sustaining therapies in patients with severe traumatic brain injury (TBI).

MATERIALS AND METHODS

We conducted a 2-year multicenter retrospective cohort study (2005-2006) in mechanically ventilated patients aged 16 years and older admitted to the intensive care units (ICUs) of six Canadian level I trauma centers following severe TBI. One hundred and twenty charts were randomly selected at each center (n = 720). Data on ICU management strategies, patients' clinical condition, surgical procedures, diagnostic imaging, and decision to withdraw life-sustaining therapies were collected. The association of factors pertaining to the injury, interventions, and management strategies with decisions to withdraw life-sustaining therapies was evaluated among non-survivors.

RESULTS

Among the 228 non-survivors, 160 died following withdrawal of life-sustaining therapies. Patients were predominantly male (69.7 %) with a mean age of 50.7 (±21.7) years old. Brain herniation was more often reported in patients who died following decisions to withdraw life-sustaining therapies (odds ratio [OR] 2.91, 95 % confidence interval [CI] 1.16-7.30, p = 0.02) compared to those who died due to other causes (e.g., cardiac arrest, shock, etc.). Epidural hematomas (OR 0.18, 95 % CI 0.06-0.56, p < 0.01), craniotomies (OR 0.12, 95 % CI 0.02-0.68, p = 0.02), and other non-neurosurgical procedures (OR 0.08, 95 % CI 0.02-0.43, p < 0.01) were less often associated with death following withdrawal of life-sustaining therapies than death from other causes.

CONCLUSIONS

Death following decisions to withdraw life-sustaining therapies is associated with specific patient and clinical factors, and the intensity of care.

'Hit & Run' model of closed-skull traumatic brain injury (TBI) reveals complex patterns of post-traumatic AQP4 dysregulation

Cerebral edema is a major contributor to morbidity associated with traumatic brain injury (TBI). The methods involved in most rodent models of TBI, including head fixation, opening of the skull, and prolonged anesthesia, likely alter TBI development and reduce secondary injury. We report the development of a closed-skull model of murine TBI, which minimizes time of anesthesia, allows the monitoring of intracranial pressure (ICP), and can be modulated to produce mild and moderate grade TBI. In this model, we characterized changes in aquaporin-4 (AQP4) expression and localization after mild and moderate TBI. We found that global AQP4 expression after TBI was generally increased; however, analysis of AQP4 localization revealed that the most prominent effect of TBI on AQP4 was the loss of polarized localization at endfoot processes of reactive astrocytes. This AQP4 dysregulation peaked at 7 days after injury and was largely indistinguishable between mild and moderate grade TBI for the first 2 weeks after injury. Within the same model, blood-brain barrieranalysis of variance permeability, cerebral edema, and ICP largely normalized within 7 days after moderate TBI. These findings suggest that changes in AQP4 expression and localization may not contribute to cerebral edema formation, but rather may represent a compensatory mechanism to facilitate its resolution.

[Nutritional therapy in traumatic brain injury : Update 2012]

Severe traumatic brain injury ranks among the most common causes of death in young adults in western countries. Severe traumatic brain injury is typically followed by a pronounced pathophysiological cascade that accounts for many deaths. The aim of intensive care medicine after traumatic brain injury is to minimize and to control the consequences of this potentially fatal cascade. The avoidance of hypoxemia, arterial hypotension, intracranial hypertension, hyperthermia, hyperglycemia, hypoglycemia and thromboembolic complications is essential in preventing this cascade. The effect of nutrition has been rather underestimated as a means of improving the outcome after traumatic brain injury. Nutrition should be started within the first 24 h after trauma. Enteral, wherever applicable, should be the route of administration of nutrition. Enteral administration of the whole calculated calorie requirement on day 1 after trauma, if possible, lowers the infection and overall complication rates. The present review gives an update of a practical approach to nutrition in traumatic brain injury.

Epidemiology of neurologically disabling disorders

Neurological disorders place a considerable burden upon individuals, their families, and society. Some like stroke are common, while others like amyotrophic lateral sclerosis are much rarer. Some conditions such as multiple sclerosis are reported to vary by latitude, while others such as traumatic brain injury can vary considerably by locality. Depending upon the nature of the lesion, and factors such as time since onset, the consequences to the individual may also vary considerably, not just among different disorders, but within a given disorder. Consequently the patterns of disease incidence, its prevalence, and its consequences are complex and may vary not just because of the condition itself, but also because, for example, case ascertainment may vary from study to study. The cumulative annual incidence of disabling neurological disorders is likely to exceed 1000 per 100000, or 1% of the population. The incidence is characterized by significant variation, which is mediated by genetic, geographical, demographic, and environmental factors. While useful comparisons can be made through standardization techniques, planning for local services should be based upon local epidemiology, whenever available.

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.

[Prognostic factors in severe traumatic brain injury]

OBJECTIVE

To describe the factors associated to mortality of patients with severe traumatic brain injury (TBI).

DESIGN

A retrospective observational study was made of patients with severe TBI covering the period between 1 January 2007 and 31 December 2010.

SETTING

Virgen de la Vega Hospital, Salamanca (Spain).

PATIENTS

All patients hospitalized during the consecutive study period.

MAIN VARIABLES OF INTEREST

The dependent variable has been the death rate, while the independent variables were divided into two groups: epidemiological and clinical.

RESULTS

The mean patient age was the 50.84 years; 75.5% were males. The average score on the Glasgow Coma Scale (GCS) was 5.09, and the average Injury Severity Score (ISS) was 30.8. Higher mortality was observed in older patients with a higher ISS score. A total of 68.1% of the patients in which intracranial pressure (ICP) was monitored showed intracranial hypertension (ICH). The mortality rate in patients with severe TBI was 36.8%, and was associated mainly to a lower GCS score, the existence of hyperglycemia, coagulopathy, hypoxemia, the presence of mydriasis and shock. The independent mortality indicators in patients with severe TBI were the existence of mydriasis (OR: 32.75), the GCS score (OR: 2.65) and hyperglycemia (OR: 6.08).

CONCLUSIONS

The existence of mydriasis, the GCS score and hyperglycemia should be taken into account as prognostic factors in TBI patients.

Epidemiological shifts in elderly traumatic brain injury: 18-year trends in Pennsylvania

Older adults tend to have poorer outcomes compared to younger adults following moderate-to-severe traumatic brain injury (TBI). Currently, there is a need for research focusing on how elderly TBI has changed as the U.S. population shifts. This study provides a statewide account of moderate-to-severe TBI in regard to injury-related variables and incidence rates in the elderly. Data from Pennsylvania accredited trauma centers collected in the Pennsylvania Trauma Outcome Study between 1992 and 2009 were used in the current study. Incidence rates for TBI were calculated using U.S. Census Bureau estimates for individuals aged 65-90 years (separated into three subgroups: ages 65-73, 74-82, and 83-90 years). In addition, we focused on describing the following injury-related variables: mechanism of injury, injury severity, hospital length of stay, and functional status at discharge. The results indicate that the incidence of elderly TBI has approximately doubled in the past 18 years, and that the increase in elderly TBI is greatest for individuals between the ages of 83 and 90. Furthermore, this age group had the poorest outcomes following TBI. Prevention and awareness of TBI in the elderly is imperative in reducing the likelihood of injury and disability. Continued statewide work is needed to demonstrate trends in elderly TBI nationwide to further add to the knowledge base used for prevention and rehabilitation work.

Whole-body computerized tomography and concomitant spine and head injuries: a study of 355 cases

The authors present a prospective study on the coexistence of spinal injury (SI) and severe traumatic brain injury (TBI) in patients who were involved in traffic accidents and arrived at the Emergency Department of Hospital das Clinicas of the University of Sao Paulo between September 1, 2003 and December 31, 2009. A whole-body computed tomography was the diagnostic method employed in all cases. Both lesions were observed simultaneously in 69 cases (19.4%), predominantly in males (57 individuals, 82.6%). Cranial injuries included epidural hematoma, acute subdural hematoma, brain contusion, ventricular hemorrhage and traumatic subarachnoid hemorrhage. The transverse processes were the most fragile portion of the vertebrae and were more susceptible to fractures. The seventh cervical vertebra was the most commonly affected segment, with 24 cases (34.78%). The distribution of fractures was similar among the other cervical vertebrae, the first four thoracic vertebrae and the lumbar spine. Neurological deficit secondary to SI was detected in eight individuals (11.59%) and two individuals (2.89%) died. Traumatic subarachnoid hemorrhage was the most common intracranial finding (82.6%). Spinal surgery was necessary in 24 patients (34.78%) and brain surgery in 18 (26%). Four patients (5.79%) underwent cranial and spinal surgeries. The authors conclude that it is necessary a judicious assessment of the entire spine of individuals who presented in coma after suffering a brain injury associated to multisystemic trauma and whole-body CT scan may play a major role in this scenario.

Effects of aging on blood brain barrier and matrix metalloproteases following controlled cortical impact in mice

Aging alters the ability of the brain to respond to injury. One of the major differences between the adult and aged brain is that comparable injuries lead to greater blood brain barrier disruption in the aged brain. The goals of these studies were to quantify the effects of age on BBB permeability using high field strength MRI T1 mapping and to determine whether activation of matrix metalloproteases, their inhibitors, or expression of blood brain barrier structural proteins, occludin, zonnula occludins-1 (ZO-1) and claudin-5 were altered following injury to the aged C57/BL6 mouse brain. T1 mapping studies revealed greater blood brain barrier permeability in the aged (21-24 months old) brain than in the adult (4-6 months old) following controlled cortical impact. The increased blood brain barrier permeability in the pericontusional region was confirmed with IgG immunohistochemistry. MMP-9 activity was increased following controlled cortical impact in the aged brain, and this was accompanied by increased MMP-9 gene expression. MMP-2 activity was higher in the uninjured aged brain than in the adult brain. Occludin and ZO-1 mRNA levels were unchanged following injury in either age group, but claudin-5 mRNA levels were lower in the aged than the adult brain following injury. These results demonstrate quantitative increases in blood brain barrier permeability in the aged brain following injury that are accompanied by increased MMP-9 activation and decreased blood brain barrier repair responses.

Evaluation of differentiated neurotherapy programs for a patient after severe TBI and long term coma using event-related potentials

BACKGROUND

This article examines the effectiveness of differentiated rehabilitation programs for a patient with frontal syndrome after severe TBI and long-term coma. We hypothesized that there would be a small response to relative beta training, and a good response to rTMS, applied to regulate the dynamics of brain function.

CASE REPORT

M. L-S, age 26, suffered from anosognosia, executive dysfunction, and behavioral changes, after a skiing accident and prolonged coma, rendering him unable to function independently in many situations of everyday life. Only slight progress was made after traditional rehabilitation. The patient took part in 20 sessions of relative beta training (program A) and later in 20 sessions of rTMS (program B); both programs were combined with behavioral training. We used standardized neuropsychological testing, as well as ERPs before the experiment, after the completion of program A, and again after the completion of program B. As hypothesized, patient M.L-S showed small improvements in executive dysfunction and behavioral disorders after the conclusion of program A, and major improvement after program B. Similarly, in physiological changes the patient showed small improvement after relative beta training and a significant improvement of the P300 NOGO component after the rTMS program.

CONCLUSIONS

The rTMS program produced larger physiological and behavioral changes than did relative beta training. A combination of different neurotherapeutical approaches (such as neurofeedback, rTMS, tDCS) can be suggested for similar severe cases of TBI. ERPs can be used to assess functional brain changes induced by neurotherapeutical programs.

[Treatment of traumatic brain injury in Germany]

The relationship between severe, moderate and mild traumatic brain injury (TBI) as well as the course of treatment and quality management, were studied in a 1-year prospective study in regions of Hannover and Münster Germany. A total of 6,783 patients were documented at the initial examination (58.4% male, 28.1% children <16 years old) and 63.5% participated in the follow-up survey 1 year after the accident. Of these TBI patients 5,220 (73%) were admitted to hospital for clinical treatment but only 258 (<4%) received inpatient rehabilitation. The incidence of TBI was 332/100,000 inhabitants and according to the Glasgow Coma Scale (GCS) brain injury was mild in 90.9%, severe in 5.2% and moderate in 3.9%. The main cause of injury was a fall (52.5%) followed by a traffic accident (26.3%). In-hospital mortality was 1%. Only 56% of TBI patients were neurological examined and 63% were examined in hospital within the first hour after the accident. An immediate x-ray of the skull with a doubtful evidential value was made in 82%. Of the participants 35.9% were still receiving medical treatment 1 year after the accident although the majority only suffered mild TBI. An overabundance of severe socioeconomic consequences, e.g. loss of job, accommodation, family, were also found following only mild TBI.

The epidemiological trends of head injury in the largest Canadian adult trauma center from 1986 to 2007

Object

This study documents the epidemiology of head injury over the course of 22 years in the largest Level I adult trauma center in Canada. This information defines the current state, changing pattern, and relative distribution of demographic factors in a defined group of trauma patients. It will aid in hypothesis generation to direct etiological research, administrative resource allocation, and preventative strategies.

Methods

Data on all the trauma patients treated at Sunnybrook Health Sciences Centre (SHSC) from 1986 to 2007 were collected in a consecutive, prospective fashion. The authors reviewed these data from the Sunnybrook Trauma Registry Database in a retrospective fashion. The aggregate data on head injury included demographic data, cause of injury, and Injury Severity Score (ISS). The collected data were analyzed using univariate techniques to depict the trend of variables over years. The authors used the length of stay (LOS) and number of deaths per year (case fatality rate) as crude measures of outcome.

Results

A total of 16,678 patients were treated through the Level I trauma center at SHSC from January 1986 to December 2007. Of these, 9315 patients met the inclusion criteria (ISS > 12, head Abbreviated Injury Scale score > 0). The median age of all trauma patients was 36 years, and 69.6% were male. The median ISS of the head-injury patients was 27. The median age of this group of patients increased by 12 years over the study period. Motorized vehicle accidents accounted for the greatest number of head injuries (60.3%) although the relative percentage decreased over the study period. The median transfer time of patients sustaining a head injury was 2.58 hours, and there was an approximately 45 minute improvement over the 22-year study period. The median LOS in our center decreased from 19 to 10 days over the study period. The average case fatality rate was 17.4% over the study period. In multivariate analysis, more severe injuries were associated with increased LOS as was increasing time from injury to hospital presentation. Age and injury severity were independently predictive of mortality.

Conclusions

These data will provide useful information to guide future studies on the changing patterns of head injury, possible mechanisms of injury, and efficient resource allocation for management of this condition.

Post accessive social policy in the rehabilitation of adolescents following TBI

BACKGROUND

The aim of this research was to evaluate the effectiveness of the post-accessive Conduct Disorder Therapy Program administered within the "Academy of Life" in the reduction of behavioural disorder in adolescents following traumatic brain injury (TBI).

MATERIAL/METHODS

100 adolescents from Gdansk and adjacent areas, psychiatrically diagnosed with "frontal lobe syndrome" following a TBI, were examined. Group A included 50 participants examined and treated at the Reintegration and Training Center of the Foundation for Persons with Brain Dysfunctions. Group B comprised 50 people matched for age and sex, under treatment at the Gdansk Center for Neuropsychological Studies, Gdansk-Południe Non-Public Health Care Center. Group A used the above therapy programme, while group B did not. The studies included an analysis of documentation, neuro-imaging (CT or MRI), clinical interviews, the Mini-Mental State Examination and the Frontal Behavioural Inventory.

RESULTS

The therapy program had a significant impact on conduct disorders, the most visible differences being within neurological disorders and the least visible within cognitive disorders. It also influenced the social reintegration of adolescents following TBI, as demonstrated by the greater increase in the percentage of participants from group A returning to school and hobbies practised before the accident.

CONCLUSIONS

The results indicate that the evaluated therapy program is effective in reducing behavioral disorders in adolescents following brain injury, and their reintegration into society.

Subjective well-being and quality of life following traumatic brain injury in adults: A long-term population-based follow-up

PRIMARY OBJECTIVE

To assess subjective well-being and quality-of-life in nationally representative samples of patients at long intervals following traumatic brain injuries.

METHODS AND PROCEDURES

Patients with either cranial fractures or cerebral lesions were identified in a national computer-based register of hospital admissions and random samples were selected among those who had suffered the injury at 5, 10 or 15 years prior to the follow-up. Postal questionnaires were sent to them covering quality of life, e.g. return to employment, family relations and current subjective well-being in terms of symptomatology, e.g. somatic complaints, cognitive dysfunction. A response rate of 76% was obtained, comprising 114 patients with cranial fracture and 126 with cerebral lesions.

MAIN OUTCOMES AND RESULTS

The group with cerebral lesions had markedly poorer quality of life and subjective well-being than the group with cranial fractures and this did not vary across time. In both groups, the most common symptoms concerned cognition. Among the cerebral lesion group, quality of life outcome was fairly well predicted by severity of injury, but subjective well-being was less well predicted.

CONCLUSIONS

The negative consequences of traumatic cerebral lesions are marked and do not vary at long periods following injury.

Validation of serum markers for blood-brain barrier disruption in traumatic brain injury

The blood-brain barrier (BBB), which prevents the entry into the central nervous system (CNS) of most water-soluble molecules over 500 Da, is often disrupted after trauma. Post-traumatic BBB disruption may have important implications for prognosis and therapy. Assessment of BBB status is not routine in clinical practice because available techniques are invasive. The gold-standard measure, the cerebrospinal fluide (CSF)-serum albumin quotient (Q(A)), requires the measurement of albumin in CSF and serum collected contemporaneously. Accurate, less invasive techniques are necessary. The objective of this study was to evaluate the relationship between Q(A) and serum concentrations of monomeric transthyretin (TTR) or S100B. Nine subjects with severe traumatic brain injury (TBI; Glasgow Coma Scale [GCS] score < or =8) and 11 subjects with non-traumatic headache who had CSF collected by ventriculostomy or lumbar puncture (LP) were enrolled. Serum and CSF were collected at the time of LP for headache subjects and at 12, 24, and 48 h after ventriculostomy for TBI subjects. The Q(A) was calculated for all time points at which paired CSF and serum samples were available. Serum S100B and TTR levels were also measured. Pearson's correlation coefficient and area under the receiver operating characteristic (ROC) curve were used to determine the relationship between the serum proteins and QA. Seven TBI subjects had abnormal Q(A)'s indicating BBB dysfunction. The remaining TBI and control subjects had normal BBB function. No significant relationship between TTR and QA was found. A statistically significant linear correlation between serum S100B and Q(A) was present (r = 0.432, p = 0.02). ROC analysis demonstrated a significant relationship between Q(A) and serum S100B concentrations at 12 h after TBI (AUC = 0.800; SE 0.147, 95% CI 0.511-1.089). Using an S100B concentration cutoff of 0.027 ng=ml, specificity for abnormal Q(A) was 90% or higher at each time point. We conclude that serum S100B concentrations accurately indicate BBB dysfunction at 12 h after TBI.

Mouse closed head injury model induced by a weight-drop device

Traumatic brain injury represents the leading cause of death in young individuals. Various animal models have been developed to mimic human closed head injury (CHI). Widely used models induce head injury by lateral fluid percussion, a controlled cortical impact or impact acceleration. The presented model induces a CHI by a standardized weight-drop device inducing a focal blunt injury over an intact skull without pre-injury manipulations. The resulting impact triggers a profound neuroinflammatory response within the intrathecal compartment with high consistency and reproducibility, leading to neurological impairment and breakdown of the blood-brain barrier. In this protocol, we define standardized procedures for inducing CHI in mice and determine various severity grades of CHI through modulation of the weight falling height. In experienced hands, this CHI model can be carried out in as little as 30 s per animal, with additional time required for subsequent posttraumatic analysis and data collection.

Impact of falls on early mortality from severe traumatic brain injury

BACKGROUND

The causes of severe traumatic brain injury (TBI) vary by age and other demographic characteristics. Mortality after trauma is higher for elderly than younger patients. This study is based on 2779 patients with severe TBI treated at 24 trauma centers enrolled in a New York State quality improvement program. The prospectively collected database includes information on age, sex, mechanism of injury, initial Glasgow Coma Scale score, blood pressure, pupillary assessment, and CT scan findings. This multi-center study was conducted to explore the impact of falls on early mortality from severe TBI among the elderly.

RESULTS

After exclusion criteria were applied, a total of 2162 patients were eligible for analysis. Falls contributed to 21% of all severe TBI, 12% occurring from > 3 meters and 9% from < 3 meters. Two-week mortality ranged from 18% due to injuries other than falls to 31% due to falls from < 3 meters (p =< 0.0001). Mortality after a severe TBI is much greater among older people, reaching 58% for people 65 years and older sustaining a fall from < 3 meters.

CONCLUSION

Among those 65 and older, falls contributed to 61% of all injuries and resulted in especially high mortality among individuals experiencing low falls. Preventive efforts directed toward older people to avoid falls from < 3 meters could have a significant impact on mortality.

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.

The effect of red blood cell transfusion on cerebral oxygenation and metabolism after severe traumatic brain injury

OBJECTIVE

There is evidence to suggest that anemia after severe traumatic brain injury (sTBI) is detrimental. However, there is a paucity of evidence supporting the use of transfusion of packed red blood cells in patients with sTBI. To understand the acute effect of packed red blood cell transfusion on cerebral oxygenation and metabolism in patients with sTBI.

DESIGN

Prospective clinical study.

SETTING

Addenbrooke's Neurosciences Critical Care Unit, a 21-bed tertiary academic unit.

PATIENTS

Thirty patients with sTBI.

INTERVENTIONS

Patients were randomized by computer random number generator to one of three transfusion thresholds: 8, 9, or 10 g/dL. When the patients' hemoglobin concentration fell below their assigned threshold, two units of packed red blood cells were transfused over 2 hours. A 1-hour period of stabilization was observed before final data collection.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was change in brain tissue oxygen (Pbto2). Secondary outcomes included dependence of baseline hemoglobin concentration and baseline Pbto2 on the relationship of transfusion and Pbto2, and the effect of transfusion on lactate pyruvate ratio (LPR) and brain pH as markers of cerebral metabolic state. Fifty-seven percent of patients experienced an increase in Pbto2 during the course of the study, whereas in 43% of patients, Pbto2 either did not change or decreased. Multivariable generalized estimating equation analysis revealed change in hemoglobin concentration to significantly and positively associated with change in Pbto2 [0.10 kPa/(g/dL) 95% confidence interval 0.03-0.17, p = 0.003]. Improvement in Pbto2 was not associated with baseline hemoglobin concentration or low Pbto2 (<1 kPa). Fifty-six percent of patients experienced an increase in LPR. No significant relationship between change in LPR or transfusion on pHbt and change in hemoglobin could be demonstrated.

CONCLUSIONS

Transfusion of packed red blood cells acutely results in improved brain tissue oxygen without appreciable effect on cerebral metabolism.

TRIAL REGISTRATION

ISRCTN89085577.

Long-term cognitive outcome in moderate to severe traumatic brain injury: a meta-analysis examining timed and untimed tests at 1 and 4.5 or more years after injury

OBJECTIVES

To examine long-term outcome of moderate to severe traumatic brain injury (TBI) on timed and untimed cognitive tests using meta-analysis.

DESIGN

Meta-analysis examining outcome at 2 epochs, 6 to 18 months postinjury (epoch 1) and 4.5 to 11 years postinjury (epoch 2).

SETTING

Data source was published articles (1966-2007) identified through electronic and manual search.

PARTICIPANTS

A total of 1380 subjects with moderate to severe TBI participated in the 16 studies meeting inclusion criteria.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Timed and untimed neuropsychologic tests with quantitative results (means, SDs, t, and df tests) from studies containing a healthy comparison group and a mean time since injury falling within 1 of the 2 epochs.

RESULTS

Patient versus control weighted effect sizes were medium to large at epoch 1 for both untimed tasks (r=-.46; confidence interval [CI], -.32 to -.65) and timed tasks (r=-.46; CI, -.35 to -.59). At epoch 2, effect sizes were slightly smaller for untimed tasks (r=-.38; CI, -.25 to -.60) and timed tasks (r=-.40; CI, -.32 to -.62).

CONCLUSIONS

Patients showed robust, persisting impairments on both timed and untimed tests at recovery plateau (ie, 6-18mo postinjury) and many years later. These findings converge with previous studies, though using an alternative approach that obviates some of the methodologic problems of longitudinal studies, such as selective attrition.

Actual incidences of road casualties, and their injury severity, modelled from police and hospital data, France

BACKGROUND

Nation-wide road casualty figures usually come from police data. In France, as in many developed countries, the reporting of fatalities is almost complete but the reporting of non-fatal casualties is rather low. It is moreover strongly biased. Valid estimates are needed.

METHODS

Using the capture-recapture method on police data and on a road trauma registry covering a large county of 1.6 million inhabitants, we estimate police under-reporting correction factors that account for unregistered casualties. These correction factors are then applied to the nation-wide police data, with standardization on under-reporting bias factors.

RESULTS

In 2004, whereas the police report 108,727 non-fatally injured, the estimation yields 400,200. Over the 1996-2004 study period, the average annual estimated incidence is 871/100,000 for all injured (3.4 times the police incidence), 232/100,000 for hospitalized, 103/100,000 for seriously injured (2.2 times the police incidence) and 12.6/100,000 for casualties with long-term major impairment. The incidence of seriously injured (NISS 9+) is 11.3/100,000 for pedestrians, 9.5/100,000 for cyclists, 36.3/100,000 for motorized two-wheel users and 42.5/100,000 for car users.

CONCLUSIONS

The estimated incidences are much higher than the police-based ones. This changes the scale of the road injuries issue. The risk of suffering a major impairment from a road crash is equal to the risk of being killed. Motorized two-wheel users experience a large burden of traffic casualties, much larger than that indicated by police data. The approach used can be reproduced in other countries, if an additional medical registration exists.

[The relevance of the inflammatory response in the injured brain]

Research efforts in recent years have defined traumatic brain injury (TBI) as a predominantly immunological and inflammatory disorder. This perception is based on the fact that the overwhelming neuroinflammatory response in the injured brain contributes to the development of posttraumatic edema and to neuropathological sequelae which are, in large part, responsible for the adverse outcome. While the "key" mediators of neuroinflammation, such as the cytokine cascade and the complement system, have been clearly defined by studies in experimental TBI models, their exact pathways of interaction and pathophysiological implications remain to be further elucidated. This lack of knowledge is partially due to the concept of a "dual role" of the neuroinflammatory response after TBI. This notion implies that specific inflammatory molecules may mediate diverse functions depending on their local concentration and kinetics of expression in the injured brain. The inflammation-induced effects range from beneficial aspects of neuroprotection to detrimental neurotoxicity. The lack of success in pushing anti-inflammatory therapeutic concepts from"bench to bedside" for patients with severe TBI strengthens the further need for advances in basic research on the molecular aspects of the neuroinflammatory network in the injured brain. The present review summarizes the current knowledge from experimental studies in this field of research and discusses potential future targets of investigation.

Severe traumatic brain injury in Austria IV: intensive care management

OBJECTIVES

The goal of this paper is to describe the ICU management of severe traumatic brain injury (TBI) in Austria.

PATIENTS AND METHODS

Data sets from 415 patients included by 5 Austrian hospitals were available. The analysis focused on complications and outcomes of intensive care, monitoring of intracranial pressure (ICP), efficacy of interventions to control ICP, management of hemodynamics and cerebral perfusion pressure (CPP), ventilation, and effects of hyperglycaemia.

RESULTS

Overall ICU mortality was 30.8%; 90-day mortality was 35.7%. Final outcome was favorable in 33%, unfavorable in 51%, and in 16% the final outcome was unknown. An ICP monitoring device was used in 64%; most patients received intraparenchymal sensors (77%). Events associated with mortality > 50% were CPP < 50 mm Hg for > 12 hours/day, ICP > 25 mm Hg for > 12 hours/day, and MAP < 70 mm Hg for > 18 hours/day. The use of ICP monitoring was associated with significantly reduced ICU mortality. Interventions that may have improved the outcome included the use of barbiturates (short-term), hypertonic saline, moderate hyperventilation (33 < pCO2 < 37; p < 0.001 vs. aggressive hyper-and normoventilation), and normothermia. Hyperglycaemia was associated with poor outcome.

CONCLUSIONS

Our study showed that ICU management of patients with severe TBI mostly follows international guidelines, and that outcome was comparable to or even better than that reported by other authors. Low CPP was associated with poor outcome, and was more often due to low MAP than to elevated ICP. The use of barbiturates and hypertonic saline was more common than expected. CPP should be maintained > 50 mm Hg, the use of catecholamines, fluid loading, barbiturates (short-term), moderate hyperventilation, hypertonic saline, and insulin may improve outcome after severe TBI.

Severe traumatic brain injury in Austria II: epidemiology of hospital admissions

OBJECTIVES

The goal of this paper is to describe the hospital-based epidemiology of severe TBI in Austria.

PATIENTS AND METHODS

Data sets from 492 patients included in the study by 5 Austrian hospitals were available. Age and gender distribution, education, occupation, location of trauma, mechanism of injury, alcohol use, type and severity of injury, associated injuries, length of intensive care unit stay, and intensive care unit outcome were evaluated for each of the 5 centers.

RESULTS

The sample represents roughly 13% of all cases with severe TBI which were treated in Austrian hospitals during the study period. Mean age was 48 +/- 21 years, and most patients were male (72%). The most important trauma locations were roads (50%), home (24%), outdoors (10%), and workplace (7%). Transportrelated trauma was the most important mechanism (44%) followed by falls < 3 m (30%), falls > 3 m (11%), and sports injuries (5%). Detailed analysis of transport-related trauma showed that car accidents (45%) were most common, followed by pedestrian (20%), motorbike (19%), and bicycle (16%) accidents. Significant differences between the centers were found for most of the variables analyzed. The severe traumatic brain injury was associated with spinal cord injury in 10%, and with severe multiple trauma in 38% of cases. Intensive care mortality was 31.7%. There were no significant correlations between mechanisms of injury and severity of trauma, nor between mechanisms and ICU outcome.

CONCLUSIONS

Epidemiology of severe traumatic brain injuries in Austria is not much different from other industrialized countries. Traffic accidents are responsible for the majority of traumas, stressing the importance of road injury prevention. Attention should also be paid to the specific risks of older people and to prevent injuries at home.

Head injury mortality in the Nordic countries

Traumatic brain injury (TBI) is a major cause of morbidity and mortality in Western countries. Effective management planning for these patients requires knowledge of TBI epidemiology. The purpose of this study was to describe and analyze the development of TBI mortality in the Nordic countries during the period 1987-2001. Data on TBI deaths were retrieved from the national official statistical agencies according to specified diagnostic codes. We also collected data on the number of operations for acute TBI in the year 2000 from all Nordic hospitals admitting trauma patients. Finland had about twice as high a TBI mortality rate as the other countries. Similarly, the Finnish incidence of acute TBI operations was nearly twice that of the other countries. The median TBI death rate for Finland was 21.2 per 100,000 per year, and for Denmark, Norway, and Sweden 11.5, 10.4, and 9.5, respectively. There were more male than female deaths in all countries. The mortality rate from extracranial injuries was relatively equal between the countries. We observed a sizeable reduction in TBI mortality rates for all countries, except in Finland. Younger age groups had the most pronounced decrease in TBI mortality rates. The oldest age group had the least favorable development of TBI mortality rates, and the mean age of TBI casualties increased substantially during the study period. This study demonstrates considerable differences in and between the Nordic countries regarding TBI mortality. Preventive measures and implementation of regional guidelines are needed to assure a positive development in the future.

Relative Risk of Mortality after Traumatic Brain Injury: A Population-Based Study of The Role of Age And Injury Severity

To test if observed vs. expected mortality differs by age among traumatic brain injury (TBI) cases, a population-based, historical cohort study was conducted in Olmsted County, Minnesota. From all residents with any diagnosis suggestive of TBI 1985-1999, we randomly sampled 7,800 and reviewed their medical records to confirm the event. Confirmed incident cases were categorized by age in years (<16 = pediatric, 16-65 = adult, > 65 elderly) and severity (moderate/severe vs. mild) and followed for vital status through 6/30/2004. We compared observed 6-month and 10-year mortality with expected and tested if the differences varied by age. Of 1,433 confirmed incident cases, 35% were pediatric; 55% were adult; only 9% were elderly; 11.2% of all cases were moderate/severe; the proportions by increasing age group were 11.4%, 8.5%, 26.7%. The proportions who died within 6 months increased with increasing age group, both for moderate/severe (10.3%, 40.3%, 50.0%) and mild cases (0%, 0%, 9.1%); mortality for moderate/severe cases was nearly 40 times that for mild cases, independent of age. Among 6-month survivors, 10-year mortality differed from expected only for adult cases. For all cases, after adjusting for sex, year of TBI, and severity, the difference between observed and expected 10-year mortality was greater for adult cases than for pediatric cases and similar for adult and elderly cases. Elderly individuals account for <10% of TBI cases and >50% of 10-year mortality, yet much of this discrepancy reflects age-associated mortality in general. Findings have implications for (1) reducing the number of excess deaths following TBI and (2) caring for survivors.

Activation of caspase-1 dependent interleukins in developmental brain trauma

Focal mechanical cortical trauma triggers diffuse apoptotic neurodegeneration in the developing rat brain which is associated with invasion of brain tissue with inflammatory mediators. We hypothesized that caspase-1 and the two caspase-1-processed cytokines, interleukin (IL)-1beta and IL-18, are involved in trauma-induced neuronal cell death in the developing brain. 7-day-old Wistar rats or C57/BL6 mice were subjected to head trauma using a weight drop device. Animals were sacrificed at defined time points following trauma and brains were processed for histology and molecular analyses. Neuronal cell death in the immature brain peaked at 12-24 h and was accompanied by a marked increase of mRNA and protein levels for caspase-1, IL-1beta and IL-18 within 2 to 12 h following the injury. Caspase-1 levels were elevated for 72 h, whereas IL-1beta decreased earlier at 48 h. IL-18 remained high over a period of 3 days and decreased to normal levels by day 7 after the injury. Intraperitoneal injection of recombinant human IL-18-binding protein (IL-18BP), a specific inhibitor of IL-18, attenuated traumatic brain injury. Mice deficient in IL-18 (IL-18-/-) were protected against trauma-induced brain damage. These findings indicate that IL-18 is involved in trauma-induced neuronal cell death in the immature rodent brain and might serve as a potential therapeutic target.