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

Post-mortem forensic neuroimaging: correlation of MSCT and MRI findings with autopsy results

Multislice-computed tomography (MSCT) and magnetic resonance imaging (MRI) are increasingly used for forensic purposes. Based on broad experience in clinical neuroimaging, post-mortem MSCT and MRI were performed in 57 forensic cases with the goal to evaluate the radiological methods concerning their usability for forensic head and brain examination. An experienced clinical radiologist evaluated the imaging data. The results were compared to the autopsy findings that served as the gold standard with regard to common forensic neurotrauma findings such as skull fractures, soft tissue lesions of the scalp, various forms of intracranial hemorrhage or signs of increased brain pressure. The sensitivity of the imaging methods ranged from 100% (e.g., heat-induced alterations, intracranial gas) to zero (e.g., mediobasal impression marks as a sign of increased brain pressure, plaques jaunes). The agreement between MRI and CT was 69%. The radiological methods prevalently failed in the detection of lesions smaller than 3mm of size, whereas they were generally satisfactory concerning the evaluation of intracranial hemorrhage. Due to its advanced 2D and 3D post-processing possibilities, CT in particular possessed certain advantages in comparison with autopsy with regard to forensic reconstruction. MRI showed forensically relevant findings not seen during autopsy in several cases. The partly limited sensitivity of imaging that was observed in this retrospective study was based on several factors: besides general technical limitations it became apparent that clinical radiologists require a sound basic forensic background in order to detect specific signs. Focused teaching sessions will be essential to improve the outcome in future examinations. On the other hand, the autopsy protocols should be further standardized to allow an exact comparison of imaging and autopsy data. In consideration of these facts, MRI and CT have the power to play an important role in future forensic neuropathological examination.

Impairment of lymphocyte function in head-injured rats: effects of standard and immune-enhancing diets for enteral nutrition

BACKGROUND

The metabolic response to head injury (HI) is characterized by a dysimmunity which may be a risk factor of a septic state. The use of immune enhancing diets (IEDs) could be a promising approach to improve immune functions. The aim of the study was to investigate the consequences of HI on lymphocyte function and to determine the effects of an enteral IED comparatively to a standard enteral nutrition.

METHOD

A rat model of HI by fluid percussion was used. Twenty-five male Sprague-Dawley rats were randomized into 4 groups: rats receiving standard chow diet ad libitum (AL), rats sustaining HI and receiving standard chow diet and enteral saline (HI), rats receiving the enteral standard diet Sondalis HP (HIS), and rats receiving the IED Crucial (HIC). The two enteral diets were infused continuously during 4 days after the HI and were isocaloric, isonitrogenous and isovolumic.

RESULTS

HI induced a thymus atrophy (HI vs. AL, P<0.05), and an impairment in lymphocyte CD25 receptor density responsiveness to stimulation. The IED blunted thymus atrophy and allowed to preserve the stimulation of blood and Peyer patches lymphocytes (HIC: Stimulated vs. Basal, P<0.05).

CONCLUSION

IED seems more adapted for preserving lymphocyte function than standard diet in HI patients.

Pharmacological complement inhibition at the C3 convertase level promotes neuronal survival, neuroprotective intracerebral gene expression, and neurological outcome after traumatic brain injury

The complement system represents an important mediator of neuroinflammation in traumatic brain injury. We have previously shown that transgenic mice with central nervous system-targeted overexpression of Crry, a potent murine complement inhibitor at the level of C3 convertases, are protected from complement-mediated neuropathological sequelae in brain-injured mice. This knowledge was expanded in the present study to a pharmacological approach by the use of a recombinant Crry molecule (termed Crry-Ig) which was recently made available in a chimeric form fused to the non-complement fixing mouse IgG1 Fc region. In a standardized model of closed head injury in mice, the systemic injection of 1 mg Crry-Ig at 1 h and 24 h after trauma resulted in a significant neurological improvement for up to 7 days, as compared to vehicle-injected control mice (P < 0.05, repeated measures ANOVA). Furthermore, the extensive neuronal destruction seen in the hippocampal CA3/CA4 sublayers in head-injured mice with vehicle injection only was shown to be preserved - to a similar extent as in "sham"-operated mice - by the posttraumatic injection of Crry-Ig. Real-time RT-PCR analysis revealed that the post-treatment with Crry-Ig resulted in a significant up-regulation of candidate neuroprotective genes in the injured hemisphere (Bcl-2, C1-Inh, CD55, CD59), as compared to the vehicle control group (P < 0.01, unpaired Student's t test). Increased intracerebral Bcl-2 expression by Crry-Ig treatment was furthermore confirmed at the protein level by Western blot analysis. These data suggest that pharmacological complement inhibition represents a promising approach for attenuation of neuroinflammation and secondary neurodegeneration after head injury.

Epidemiology of blunt head injury victims undergoing ED cranial computed tomographic scanning

STUDY OBJECTIVE

We sought to describe the epidemiology of emergency department (ED) patients with blunt head injury undergoing cranial computed tomography (CT) scanning for the evaluation of possible traumatic brain injury (TBI).

METHODS

Prospective, multicenter, observational study of ED patients undergoing cranial CT after blunt head injury. Patient's date of birth, sex, and race/ethnicity were documented before CT scanning. Individual patients were considered to have "significant" TBI if the official radiographic interpretation at the end of all imaging studies associated with the trauma was consistent with any of a set of predefined diagnoses. The relative prevalence of TBI among various prespecified groups from those undergoing cranial CT scanning was also calculated.

RESULTS

Of 13728 patients who were enrolled, 8988 (65%) were men and 1193 (8.7%) had a significant acute TBI. Demographic findings associated with increased risk of TBI, among patients selected for scanning, included the following: age below 10 years (relative risk [RR] = 1.44, 95% confidence interval [CI], 1.19-1.77); age above 65 years (RR = 1.59; 95% CI, 1.40-1.80), and male sex (RR = 1.27; 95% CI, 1.30-1.43).

CONCLUSION

Among patients selected for cranial CT scanning after blunt head injury, men, patients younger than 10 years, and those older than 65 years have an increased likelihood of significant TBI.

Ventilator-associated pneumonia in severe traumatic brain injury

INTRODUCTION

Pneumonia is an important cause of morbidity following severe traumatic brain injury (TBI). However, previous studies have been limited by inclusion of specific patient subgroups or by selection bias. The primary objective of this study was to describe the incidence, risk factors for, and outcome of ventilator-associated pneumonia in an unselected population-based cohort of patients with severe TBI. An additional goal was to define the relationship of ventilator-associated pneumonia (VAP) with nonneurological organ dysfunction.

METHODS

A prospective, observational cohort study was performed at Foothills Medical Centre, the sole adult tertiary-care trauma center servicing southern Alberta. All patients with severe TBI requiring ventilation for more than 48 hours between May 1, 2000 and December 30, 2002 were included.

RESULTS

A total of 60 patients (45%) acquired VAP for an incidence density of 42.7/1000 ventilator days. Patients with polytrauma were at higher risk (risk ratio 1.7, 95% confidence interval, 0.9-3.1) for development of VAP than those with isolated head injury. Development of VAP was associated with a significantly greater degree of nonneurological organ system dysfunction. Although VAP was not associated with increased hospital mortality, patients who developed VAP had a longer duration of mechanical ventilation (15 versus 8 days, p < 0.0001), longer intensive care unit (17 versus 9 days, p < 0.0001) and hospital (60 versus 28 days, p = 0.003) lengths of stay, and more often required tracheostomy (35 versus 18%, p = 0.003).

CONCLUSIONS

VAP occurs frequently and is associated with significant morbidity in patients with severe TBI.

[Traumatic brain injury: impact on timing and modality of fracture care]

Traumatic brain injury (TBI) represents the major "killing factor" after trauma in young individuals. Those patients who survive the initial injury are highly susceptible to secondary insults to the injured brain which are mainly caused by hypotension and/or hypoxia in the early resuscitative period. Furthermore, a potent inflammatory cascade is initiated within the injured brain which leads to the development of brain edema and delayed neuronal cell death. This profound endogenous neuroinflammatory response after TBI, which is phylogenetically aimed at repairing lesioned tissue and defending the brain from invading pathogens, is in large part responsible for the extent of secondary brain damage and adverse outcome. Thus, the optimal management of the multiply injured patient, based on a thorough understanding of the pathophysiological alterations after TBI, should avoid an iatrogenic "second hit" which may be devastating to the injured brain. The standard approach of "early total care" for isolated fractures should be strictly avoided in brain-injured patients in favor of an "orthopedic damage control" concept with temporary external fixation of long bone fractures and priority given to early transfer to intensive care. The present review provides an up-to-date overview on the neuroinflammatory pathophysiology of brain injury and its implications for an optimized concept of fracture care in TBI patients.

Fatores de risco para dependência após trauma crânio-encefálico

OBJETIVO: identificar entre as características das vítimas de trauma crânio-encefálico contuso (idade, sexo, escolaridade, antecedentes, tempo de internação, complicações pós-traumáticas e indicadores da gravidade do trauma e lesão craniana) fatores de risco para prognóstico desfavorável. MÉTODOS: análise de 63 vítimas, com idade entre 12 e 65 anos, em seguimento ambulatorial em centro para atendimento de trauma, entre 6 meses e 3 anos após evento traumático. Utilizando-se a regressão logística múltipla foi construído um modelo para condição funcional. RESULTADOS: indivíduos que alcançaram pontuação 5 no máximo Abbreviated Injury Scale da região cabeça tiveram 4,89 vezes mais chance de dependência quando comparados com os que apresentaram escore menor. Vítimas internadas durante 12 dias ou mais mostraram 5,76 vezes mais chance para se tornarem dependentes em relação às demais. CONCLUSÃO: os fatores de risco para dependência foram o máximo Abbreviated Injury Scale da região cabeça e o tempo de internação.

Fatal traffic injuries among pedestrians, bicyclists and motor vehicle occupants

The objective of this study was to investigate characteristic injuries of pedestrians and bicyclists (unprotected) compared to motor vehicle occupants' (protected) in fatal traffic accidents. Cases of 664 fatal traffic accidents (371 pedestrians, 45 bicyclists, and 248 motor vehicle occupants) were collected from 1999 to 2001 using the database of the Forensic Institute in Budapest. Autopsy reports were analyzed. Location of injuries, blood alcohol levels, seasonal distribution and natural diseases influencing accident outcome were evaluated. For statistical analysis, odds ratio (OR) with 95% confidence interval (CI) was used by a conditional logistic regression. There were substantial differences in distribution of injuries suffered by pedestrians, bicyclists and motor vehicle occupants. Among pedestrians and bicyclists there was a higher rate of head injuries, such as skull fractures, epidural haemorrhage, subdural haemorrhage, brain contusion, and injuries of the lower extremities. Thoracic damages, such as traumatic aortic rupture, hemothorax, and abdominal damages, like liver rupture were dominant in motor vehicle occupants. Considering existing natural diseases, coronary artery disease was the only one with higher occurrence among motor vehicle occupants 24 (9.7%) compared with pedestrians and bicyclist 36 (8.6%). These results underline the importance of preventive strategies in transportation, pointing out that different methods are necessary to reduce fatal injuries of various traffic participants.

Bench-to-bedside review: Apoptosis/programmed cell death triggered by traumatic brain injury

Apoptosis, or programmed cell death, is a physiological form of cell death that is important for normal embryologic development and cell turnover in adult organisms. Cumulative evidence suggests that apoptosis can also be triggered in tissues without a high rate of cell turnover, including those within the central nervous system (CNS). In fact, a crucial role for apoptosis in delayed neuronal loss after both acute and chronic CNS injury is emerging. In the current review we summarize the growing evidence that apoptosis occurs after traumatic brain injury (TBI), from experimental models to humans. This includes the identification of apoptosis after TBI, initiators of apoptosis, key modulators of apoptosis such as the Bcl-2 family, key executioners of apoptosis such as the caspase family, final pathways of apoptosis, and potential therapeutic interventions for blocking neuronal apoptosis after TBI.

Preinjury warfarin use among elderly patients with closed head injuries in a trauma center

BACKGROUND

This study aimed to determine the impact of warfarin use on the severity of injury among elderly patients presenting with closed head injuries.

METHODS

A cohort of patients 55 years of age or older with closed head injuries taken to a tertiary trauma center between April 1993 and March 2001 was retrospectively identified. Patient characteristics, mechanism of injury, type and severity of injury, and hospital survival data were obtained from the trauma registry. Each case then was reviewed for completeness of information, assessment of preinjury warfarin use, and comorbidity.

RESULTS

Among the 384 patients presenting with closed head injuries, 35 (9%) were receiving warfarin before their trauma. As compared with nonusers, anticoagulated patients had a higher frequency of isolated head trauma (54% vs. 32%; p = 0.008), more severe head injuries (65.7% vs. 44.1%; p = 0.02), and a higher rate of mortality (40% vs. 21%, p = 0.01). These associations remained evident even after population differences in age, gender, comorbidities, and mechanism of injury were taken into account. Indeed, according to multivariate logistic regression models, warfarin use was associated with a statistically significant risk of death (odds ratio [OR], 2.73; 95% confidence interval [CI], 1.22-6.12), statistically significant odds for more severe head injury (OR, 2.39; 95% CI, 1.10-5.17), and odds for isolated head injury that almost reached statistical significance (OR, 1.79; 95% CI, 0.82-3.90).

CONCLUSIONS

Among patients 55 years of age or older who present with closed head injury, the use of warfarin before trauma appears to be associated with a higher frequency of isolated head trauma, more severe head trauma, and a higher likelihood of death. The findings of this retrospective study support the concern about the adverse effects of anticoagulants in cases of head trauma.

[Medical prehospital rescue in head injury]

OBJECTIVE

To evaluate the effectiveness of prehospital medical care in head-injured patients.

PATIENTS AND METHODS

All head-injured patients admitted in Bicêtre hospital from 1995 to 1999 were retrospectively studied. Glasgow Coma Scale (GCS) score, mean arterial pressure (MAP) and SpO(2) measured on the field were compared to GCS, MAP and SpO(2) on arrival in the hospital. All treatments given during transport and first data recorded in the hospital were noted. Each parameter was compared to outcome at 6 months. Then, significant parameters were compared with a multivariate analysis.

RESULTS

Three hundred and four patients were included, 80% had a GCS <or= 8 and 45% a GCS = 3. At 6 months, 43% of the patients had no or mild sequelae and 45% died. Prehospital time was 2 h 55 min +/- 1 h 40 min. During transport, 75% of hypoxemic events were corrected, but GCS and MAP decreased significantly. None of the patients with non-reactive mydriasis received any osmotherapy and all patients with non-reactive mydriasis until hospital admission died (n = 55). After multivariate analysis, parameters significantly related to outcome were, on the field, MAP (p < 0.025) and at hospital SAPS II (p < 0,001), GCS (p < 0.001), non-reactive mydriasis (p < 0.025), hyperglycemia (p < 0.025) and low haemoglobinemia (p < 0.001).

CONCLUSION

Respect of guidelines is important to improve medical care. Prehospital management corrected hypoxemia but not hypotension. The lack of osmotherapy after mydriasis cannot be explained and is probably an error. Patient route must be simplified to decrease time delay from field to hospital. Improvement in prehospital care may decrease mortality in head-injured patients.

Moderate and severe traumatic brain injury: epidemiologic, imaging and neuropathologic perspectives

This article examines 3 contexts in which moderate or severe traumatic brain injury can be approached. The epidemiologic background of moderate and severe traumatic brain injury is presented, with particular attention paid to new findings from the study of a national hospital inpatient database. We review aspects of neuroimaging and how new imaging modalities can reveal fine detail about traumatic brain injury. Finally we examine the current state of neuropathologic evaluation of, and recent developments in, understanding of the neural disruptions that occur following traumatic brain injury, together with cellular reactions to these disruptions.

Epidemiological aspect of traumatic brain injury in Northeast Italy

BACKGROUND

Traumatic brain injuries (TBIs) remain an important public health problem in developed countries. Hospital records were reviewed to ascertain the epidemiology of TBIs in Northeast Italy.

METHODS

The annual rates of TBI-associated hospitalisation were estimated by analysing data collected from hospital records from 1996 to 2000. TBIs were identified according to the Centers for Disease Control and Prevention definition and the ICDMAP-90 was used to assess their severity.

FINDINGS

55,368 TBIs were collected between 1996 and 2000, with an overall 29.4% decline in the number of cases. As for severity, moderate TBIs dropped by 34.1%, whereas a less conspicuous decline was observed for mild injuries. Severe injuries remained stable between 1996 and 1999, but rose in 2000, when the unclassified injuries were better distributed. Concerning outcome, fatal TBIs dropped slightly, but only in 2000. Causes of TBI were recorded in 59.2% of cases: 48.5% were motor vehicle accidents, 8.8% occurred at work and 12.2% at home. There were more males than females in all age groups. The highest number of cases per 100,000 person of motor vehicle accidents was recorded among 16-25 year-old and 36.5% occurred at weekends. Domestic accidents showed two age peaks, in children and the elderly. Occupational accidents occurred at all working ages, tending to decline with older age.

INTERPRETATION

Better health care and educational campaigns may have contributed to the declining rate of TBI-associated hospitalisation. Special efforts should be made to further reduce the motor vehicle accidents involving young people and welfare programs are needed to limit the risk of falls and contain functional impairment in the elderly.

Brain and Spinal Cord Injury

Up to 50% of all trauma deaths in the United States involve significant injury to the brain or spinal cord. This chapter highlights the public health significance of traumatic brain and spinal cord injury and examines methodological issues in studies of the epidemiology of these injuries. It addresses methodological challenges in epidemiologic and clinical studies of brain and spinal cord injury, including difficulties in case ascertainment, differing approaches to brain injury classification, and measurement issues in brain injury severity and outcome scales. The chapter summarizes scientific literature addressing demographic and lifestyle risk factors for brain injury including age, sex, and alcohol consumption. External causes of traumatic brain and spinal cord injury are also discussed, including transportation-related injuries and increasingly recognized sports-related brain injuries.

[The impact of a French guideline on the clinical management of severe head injury (SHI) published in 1999]

OBJECTIVE

To evaluate the impact of a French guideline on the clinical management of severe head injury (SHI) published in 1999.

STUDY DESIGN

Nationwide survey.

METHODS

182 medical centres answered the inquiry.

RESULTS

111 centres declared to manage such patients suffering from SHI. 68% of doctors from these clinical departments did report to have read these guidelines. Fifty percent of them found in these guidelines useful data for their clinical practice. Forty four percent of centres could not monitor ICP lacking neurosurgical facility in their hospital. Conversely, all hospitals with neurosurgery available did monitor ICP. Seventy six percent of centres reported difficulties to find a facility, which would take these patients in charge when discharged from ICU. We analysed the main items included in the guidelines and report their impact. Seventy four percent of responders found that clinical management of SHI patients had improved during the last years.

CONCLUSION

The French guidelines had a significant impact and seem to have provided a useful aid to clinical management of SHI patients. ICP monitoring and the shortage in post-ICU facilities are remaining issues.