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

Prediction of Outcome at Discharge From Acute Care Following Traumatic Brain Injury

OBJECTIVE

To compute outcome probabilities for persons with traumatic brain injury at discharge from acute care.

PARTICIPANTS

Three hundred thirty-nine patients with traumatic brain injury (239 mild, 48 moderate, 52 severe).

SETTING

Level I trauma center.

MAIN MEASURES

Predictor variables considered were age, education, Glasgow Coma Scale score, duration of posttraumatic amnesia, cerebral imaging results, and need for neurosurgical intervention. Outcome measures were Extended Glasgow Outcome Scale and discharge destination.

RESULTS

Logistic regressions showed that a shorter posttraumatic amnesia decreased the probability of moderate to severe disability. Moreover, discharge home was less probable for patients with positive cerebral imaging.

CONCLUSION

This model can help predict rehabilitation needs upon discharge from an acute care hospital.

Traumatic injury in the older adult from head to toe

This review demonstrates essential issues to consider when caring for older trauma patients, including baseline physical status, mental health, comorbidities, and risk factors for sequelae and future injuries. The impact of a traumatic injury on older adults is complex. Issues of normal aging, functional status, chronic health conditions, and response to treatment affect health care and related decisions. Studies that have examined outcomes for older trauma patients to date have been mainly descriptive or confined to a single institution, limiting our ability to generalize. Other studies, using large data sets, have provided some information regarding possible primary prevention strategies, yet have limitations in the individual level detail collected. Nevertheless, this review also demonstrates the dearth of available evidence-based recommendations that provides support to treatment protocols in this complex and diverse patient population. The lack of an evidence base to use in the management of older trauma patients demonstrates the critical need for research in this rapidly growing population. An example of one such area includes the use of pulmonary artery catheters in older trauma patients. Although evidence to date suggests that pulmonary artery catheters are of benefit in the management of patients with physiologic compromise, it is unclear whether using these published cardiac output management recommendations leads to improved outcomes. In light of newly published data suggesting equivocal benefit from use of pulmonary artery catheters, with increased side effects, this controversy is an important area for future research. Critical care nurses, with their emphasis on multidisciplinary, holistic practice, can expand their influence as essential members of the interdisciplinary team caring for older trauma patients by cultivating geriatric specialty knowledge. Older trauma patients would benefit greatly from this type of specialty nursing care during all phases of the recovery trajectory, particularly in terms of adequate symptom management and prevention of sequelae, as well as with timely and appropriate initiation of consultative services. Using the intersection of primary and secondary prevention as the overall guide for practice, critical care nurses and other health care providers who possess an understanding of aging processes and comorbid conditions can significantly improve outcomes for older adults with traumatic injuries.

Traumatic brain injury in older adults: epidemiology, outcomes, and future implications

Traumatic brain injury (TBI) is a significant problem in older adults. In persons aged 65 and older, TBI is responsible for more than 80,000 emergency department visits each year; three-quarters of these visits result in hospitalization as a result of the injury. Adults aged 75 and older have the highest rates of TBI-related hospitalization and death. Falls are the leading cause of TBI for older adults (51%), and motor vehicle traffic crashes are second (9%). Older age is known to negatively influence outcome after TBI. Although geriatric and neurotrauma investigators have identified the prognostic significance of preadmission functional ability, comorbidities, sex, and other factors such as cerebral perfusion pressure on recovery after illness or injury, these variables remain understudied in older adults with TBI. In the absence of good clinical data, predicting outcomes and providing care in the older adult population with TBI remains problematic. To address this significant public health issue, a refocusing of research efforts on this population is justified to prevent TBI in the older adult and to discern unique care requirements to facilitate best patient outcomes.

Adjustment for Strong Predictors of Outcome in Traumatic Brain Injury Trials: 25% Reduction in Sample Size Requirements in the IMPACT Study

The aim of this study was to quantify the potential reduction in sample size that can be achieved by adjustment for predictors of outcome in traumatic brain injury (TBI) trials. We used individual patient data from seven therapeutic phase III randomized clinical trials (RCTs; n = 6166) in moderate or severe TBI, and three TBI surveys (n = 2238). The primary outcome was the dichotomized Glasgow Outcome Scale at 6 months (favorable/unfavorable). Baseline predictors of outcome considered were age, motor score, pupillary reactivity, computed tomography (CT) classification, traumatic subarachnoid hemorrhage, hypoxia, hypotension, glycemia, and hemoglobin. We calculated the potential sample size reduction obtained by adjustment of a hypothetical treatment effect for one to seven predictors with logistic regression models. The distribution of predictors was more heterogeneous in surveys than in trials. Adjustment of the treatment effect for the strongest predictors (age, motor score, and pupillary reactivity) yielded a reduction in sample size of 16-23% in RCTs and 28-35% in surveys. Adjustment for seven predictors yielded a reduction of about 25% in most studies: 20-28% in RCTs and 32-39% in surveys. A major reduction in sample size can be obtained with covariate adjustment in TBI trials. Covariate adjustment for strong predictors should be incorporated in the analysis of future TBI trials.

Factors associated with mortality in critically injured trauma patients who require simultaneous cultures

BACKGROUND

In trauma patients surviving their initial injuries, infectious complications and multiple organ failure represent the major causes of death after the first 72 hours. Critically injured trauma patients frequently have bacteria recoverable simultaneously from multiple culture sites; the clinical significance of this event is unknown. The objective of this study was to identify the association between growth patterns of multiple site cultures and mortality among critically injured trauma patients.

METHODS

We performed a retrospective chart review collecting demographic and medical data on admissions to a state-designated Level I trauma center from April 2000 to December 2002. The inclusion criteria were age >17 years, admission to the trauma intensive care unit (TICU), and simultaneous sampling of blood, sputum, and urine in the setting of fever of undetermined origin or alteration in the white blood cell count. Four mutually exclusive groups were developed according to the number of positive culture sites. We used standard statistical analysis and multivariate logistic regression.

RESULTS

During the study period, 3,402 patients were admitted to the trauma service of whom 124 met the inclusion criteria. Eighty percent of these (99) were male, and the average age was 41 years. The median TICU stay was 17 days. The mortality rate was 24.2% (30 nonsurvivors). The survivors and non-survivors were comparable in injury severity score (ISS), initial base deficit, initial hematocrit, initial blood pressure, and hospital length of stay (p > 0.05), whereas age (p = 0.03), female sex (p = 0.04), and TICU stay (p < 0.01) were higher among non-survivors. More non-survivors showed growth of microorganisms in simultaneous blood, sputum, and urine cultures (p = 0.02). By multivariate analysis, adjusting for age, sex, and TICU length of stay, patients with growth of microorganisms in simultaneous cultures (blood, sputum, and urine) had a 3-fold greater mortality rate (OR, 3.20; 95% CI 1.05, 9.73).

CONCLUSIONS

In this group of patients, growth of bacteria in simultaneous cultures was associated with higher mortality-a factor that may be considered a poor prognostic indicator. This factor requires further studies to explore the relation with survival in critically injured patients.

Subgroup analysis and covariate adjustment in randomized clinical trials of traumatic brain injury: a systematic review

OBJECTIVE

Few randomized clinical trials (RCTs) in the field of traumatic brain injury (TBI) have shown a significant treatment benefit. We critically reviewed the use of two types of secondary analyses, covariate adjustment and subgroup analysis, which are common in TBI trials.

METHODS

We performed a systematic review of therapeutic phase III RCTs, including adult patients with acute, moderate-to-severe TBI. Glasgow Outcome Scale (GOS) at > or =3 months as outcome, and > or =50 patients per arm were required. We compared the actual reporting of covariate adjustment and subgroup analyses with the Consolidated Standards of Reporting Trials (CONSORT) recommendations. Likewise, we reviewed six protocols of large multicenter RCTs and compared planned and reported subgroups.

RESULTS

We identified 18 RCTs (n = 6439). Sixteen trials used GOS at 6 months as outcome. Five RCTs reported covariate adjustment. The number of covariates was limited (< or =5), most frequently including age. Many covariates were outcome predictors. Four RCTs reported only adjusted treatment effects as the main efficacy parameter. Eleven RCTs reported subgroup analyses. Several subgroup factors (< or =7, mainly outcome predictors) and outcomes (< or =4) were included. The highest total number of subgroups was 15, and only three RCTs completely pre-specified subgroups. Notably, 10 of 11 RCTs performed inappropriate separate subgroup analyses. Of 11 RCTs, 5 gave subgroups the same emphasis as the overall effect. Reported subgroup analyses were insufficiently described and clearly differed from those planned in the protocol.

CONCLUSION

The reported covariate adjustment and subgroup analyses from TBI trials had several methodological shortcomings. Appropriate performance and reporting of covariate adjustment and subgroup analysis should be considerably improved in future TBI trials because interpretation of treatment benefits may be misleading otherwise.

Incidence and risk factors of severe traumatic brain injury resulting from road accidents: a population-based study

A population-based study was carried out in 1996-2001 to provide the incidence and to identify the risk factors of severe traumatic brain injury (TBI) resulting from a road accident. The severe TBI was defined as an injury to the brain or the skull, excluding scalp injuries, with an abbreviated injury scale (AIS) severity score greater than 2. The severe TBI of 1238 patients were described. The annual incidence and mortality of severe TBI were, respectively, 13.7 per 100,000 and 5.3 per 100,000. The fatality rate increased from 20% in childhood to 71% over 75-year-old. Compared to restrained car occupants, the odds ratio for having a severe TBI was 18.1 (95% confidence interval, CI=12.8-25.5) for un-helmeted motorcyclists, 9.2 (95% CI=7.5-11.3) for pedestrians, 6.4 (95% CI=4.7-8.8) for un-helmeted cyclists, 3.9 (95% CI=3.1-4.8) for unrestrained car occupants and 2.8 (95% CI=2.2-3.5) for helmeted motorcyclists. Even after adjustment for several severity factors, male gender and age above 55 were both risk factors. Prevention programs aiming at improving the head protection should be promoted. The circumstances of the accident should be taken into account to predict a severe TBI.

Recovery at one year following isolated traumatic brain injury: a Western Trauma Association prospective multicenter trial

BACKGROUND

Age has been shown to be a primary determinant of survival following isolated traumatic brain injury (TBI). We have previously reported that patients > or =65 years who survived mild TBI have decreased functional outcome at 6 months compared with younger patients. The purpose of this study was to further investigate the effect of age on outcome at 1 year in all patients surviving isolated TBI.

METHODS

The Western Trauma Association multicenter prospective study included all patients sustaining isolated TBI defined as Abbreviated Injury Scale score for Head > or = 3 with an Abbreviated Injury Scale score in any other body area < or = 1. Outcome data included discharge disposition, Glasgow Outcome Scale score (1 = dead to 5= full recovery) and modified Functional Independence Measure (FIM) score measuring feeding, expression, and locomotion (1 = total dependence to 4 = total independence) for each component at discharge and 1 year.

RESULTS

In all, 295 patients were enrolled with a follow-up of 82%, resulting in 241 study patients. An additional five patients died from non-TBI causes and were excluded. The mean and median times for the last follow-up in the 236 remaining patients were 307 and 357 days, respectively. Patients were divided into four age ranges: 18 to 29 years (n = 66), 30 to 44 years (n = 54), 45 to 59 years (n = 50), and > or =60 years (n = 65). More severe TBIs, as measured by admitting Glasgow Coma Scale (GCS), were observed in the youngest group compared with all others but there were no differences in mean GCS between the remaining three groups. There were no differences in neurosurgical intervention between the groups. Age was a major determinant in the outcome at discharge and last follow-up. Patients over 60 years discharged with a GOS < or =4 were less likely to improve at 1 year than all other groups (37% versus 63 to 85%; p < or = 0.05). Patients between 18 and 29 years of age had the lowest mean Glasgow Outcome Scale and discharge FIM scores, which correlated with the low admission GCS. Despite the increased severity of TBI, this group had the best FIM score at 1 year. In contrast, patients older than 60 years had the least improvement and had a significantly lower final FIM score at 1 year compared with all other groups.

CONCLUSION

Older patients following isolated TBI have poorer functional status at discharge and make less improvement at 1 year compared with all other patients. These worse outcomes occur despite what appears to be less severe TBI as measured by a higher GCS upon admission. Differences in outcome begin to appear even in patients between 45 and 59 years. Further investigations with more detailed outcome instruments are required to better understand the qualitative limitations of a patient's recovery and to devise strategies to maximize functional improvement following TBI. Age is an exceedingly important parameter affecting recovery from isolated TBI.

A Follow-Up Study of Older Adults With Traumatic Brain Injury: Taking Into Account Decreasing Length of Stay

OBJECTIVE

To examine age-related differences in rehabilitation outcomes following traumatic brain injury (TBI).

DESIGN

Retrospective collaborative study.

SETTING

Patients received acute neurotrauma and inpatient rehabilitation services at 1 of the 17 National Institute on Disability and Rehabilitation Research-designated Traumatic Brain Injury Model Systems (TBIMS) centers.

PARTICIPANTS

A sample of 273 older patients (> or =55y) admitted for TBI were taken from the TBIMS National Database. Older patients were matched with subjects 44 years of age or younger, based on severity of injury (Glasgow Coma Scale score, length of coma, intracranial pressure elevations). Due to decreasing length of stay (LOS), only patients admitted from 1996 through 2002 were included.

INTERVENTION

Inpatient interdisciplinary brain injury rehabilitation.

MAIN OUTCOME MEASURES

Acute care LOS, inpatient rehabilitation LOS, admission and discharge FIM instrument and Disability Rating Scale (DRS) scores, FIM and DRS efficiency, acute and rehabilitative charges, and discharge disposition.

RESULTS

One-way analyses of variance demonstrated a statistically significant difference between older and younger patients with respect to LOS in rehabilitation but not for acute care. Total rehabilitative charges, and admission and discharge DRS and FIM scores also showed statistically significant differences between groups. Older patients progressed with significantly less efficiency on both the DRS and FIM scales. Significantly more charges were generated per unit for older patients to improve on the DRS scale, but not the FIM scale. Using chi-square analysis, a statistically significant difference in rate of discharge to home was identified between older (80.5%) and younger (94.4%) patients.

CONCLUSIONS

Results in this study are similar to those in earlier studies with smaller sample sizes. Major differences observed include significantly slower and more costly progress in inpatient rehabilitation for older patients with TBI, as well as a significantly lower rate of discharge to community for older patients. However, even with decreasing LOS in both settings, community discharge rate is still encouraging for older patients with TBI.

Experimental models of traumatic brain injury: do we really need to build a better mousetrap?

Approximately 4000 human beings experience a traumatic brain injury each day in the United States ranging in severity from mild to fatal. Improvements in initial management, surgical treatment, and neurointensive care have resulted in a better prognosis for traumatic brain injury patients but, to date, there is no available pharmaceutical treatment with proven efficacy, and prevention is the major protective strategy. Many patients are left with disabling changes in cognition, motor function, and personality. Over the past two decades, a number of experimental laboratories have attempted to develop novel and innovative ways to replicate, in animal models, the different aspects of this heterogenous clinical paradigm to better understand and treat patients after traumatic brain injury. Although several clinically-relevant but different experimental models have been developed to reproduce specific characteristics of human traumatic brain injury, its heterogeneity does not allow one single model to reproduce the entire spectrum of events that may occur. The use of these models has resulted in an increased understanding of the pathophysiology of traumatic brain injury, including changes in molecular and cellular pathways and neurobehavioral outcomes. This review provides an up-to-date and critical analysis of the existing models of traumatic brain injury with a view toward guiding and improving future research endeavors.

Outcome after traumatic brain injury: effects of aging on recovery

OBJECTIVE

To identify differences in outcome after traumatic brain injury (TBI) compared with orthopedic injuries as a function of age.

DESIGN

Longitudinal data analyses from an inception cohort.

SETTING

Outpatient rehabilitation program.

PARTICIPANTS

Eighty-two orthopedic injury patients and 195 TBI patients.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Independent living, employment, and level of functioning 1 to 2 years after injury.

RESULTS

Older patients and those with TBI were more likely to have increased dependence postinjury. Older TBI patients were more likely to have changes in employment status compared with orthopedic injury patients younger or TBI. The Mayo-Portland Adaptability Inventory and Disability Rating Scale were moderately predictive of level of functioning, return to employment, and independent living status 1 to 2 years postinjury. Injury severity was only mildly predictive of outcome.

CONCLUSIONS

The effect of age on outcome affects recovery from neurologic injuries and, to a lesser extent, orthopedic injuries. Outcome after TBI is best predicted by patients' age and estimates of level of function at discharge. Findings suggest that older patients and those with TBI have a greater likelihood of becoming physically and financially dependent on others. Rehabilitation efforts should focus on maximizing levels of independence to limit financial and emotional costs to patients and their families.

Predicting Outcome after Traumatic Brain Injury: Development and Validation of a Prognostic Score Based on Admission Characteristics

The early prediction of outcome after traumatic brain injury (TBI) is important for several purposes, but no prognostic models have yet been developed with proven generalizability across different settings. The objective of this study was to develop and validate prognostic models that use information available at admission to estimate 6-month outcome after severe or moderate TBI. To this end, this study evaluated mortality and unfavorable outcome, that is, death, and vegetative or severe disability on the Glasgow Outcome Scale (GOS), at 6 months post-injury. Prospectively collected data on 2269 patients from two multi-center clinical trials were used to develop prognostic models for each outcome with logistic regression analysis. We included seven predictive characteristics-age, motor score, pupillary reactivity, hypoxia, hypotension, computed tomography classification, and traumatic subarachnoid hemorrhage. The models were validated internally with bootstrapping techniques. External validity was determined in prospectively collected data from two relatively unselected surveys in Europe (n = 796) and in North America (n = 746). We evaluated the discriminative ability, that is, the ability to distinguish patients with different outcomes, with the area under the receiver operating characteristic curve (AUC). Further, we determined calibration, that is, agreement between predicted and observed outcome, with the Hosmer-Lemeshow goodness-of-fit test. The models discriminated well in the development population (AUC 0.78-0.80). External validity was even better (AUC 0.83-0.89). Calibration was less satisfactory, with poor external validity in the North American survey (p < 0.001). Especially, observed risks were higher than predicted for poor prognosis patients. A score chart was derived from the regression models to facilitate clinical application. Relatively simple prognostic models using baseline characteristics can accurately predict 6-month outcome in patients with severe or moderate TBI. The high discriminative ability indicates the potential of this model for classifying patients according to prognostic risk.

Effect of aging on the microglial response to peripheral nerve injury

Microglial morphology and immunophenotype have been studied extensively in aging-related neurodegenerative diseases, but to a lesser extent in the normally aged CNS, and little is known about how aging affects the ability of microglia to respond to neuronal injury. The goal of the current study was to determine if aging affects the ability of microglia to divide during the early response to facial nerve axotomy. In addition, we investigated the incidence of microglial cell death during later post-axotomy time points to determine if aging had an effect on microglial turnover. We employed DNA labeling with 3H-thymidine, TUNEL and lectin histochemistry after facial nerve axotomy in young (3 months), middle-aged (15 months), and old (30 months) Fisher344-Brown Norway hybrid rats. Proliferation of microglia in old rats remained significantly higher than in young rats 4 days after injury, suggesting that regulation of microglial proliferation changes with aging. There was no aging-related difference in microglial TUNEL staining at 7, 14 or 21 days post-axotomy. Lectin histochemistry in the unoperated facial nucleus revealed aging-related morphological changes in resting microglia, including hypertrophy of the cytoplasm with dense perinuclear staining. Aging-related differences in activated microglia on the lesioned side were more subtle, although many activated microglia of aged animals continued to exhibit dense perinuclear lectin reactivity. We propose that aging-related changes in morphology in conjunction with a less regulated proliferative response in the aged facial nucleus may be a reflection of microglial senescence.

Lateral fluid percussion brain injury: a 15-year review and evaluation

This article comprehensively reviews the lateral fluid percussion (LFP) model of traumatic brain injury (TBI) in small animal species with particular emphasis on its validity, clinical relevance and reliability. The LFP model, initially described in 1989, has become the most extensively utilized animal model of TBI (to date, 232 PubMed citations), producing both focal and diffuse (mixed) brain injury. Despite subtle variations in injury parameters between laboratories, universal findings are evident across studies, including histological, physiological, metabolic, and behavioral changes that serve to increase the reliability of the model. Moreover, demonstrable histological damage and severity-dependent behavioral deficits, which partially recover over time, validate LFP as a clinically-relevant model of human TBI. The LFP model, also has been used extensively to evaluate potential therapeutic interventions, including resuscitation, pharmacologic therapies, transplantation, and other neuroprotective and neuroregenerative strategies. Although a number of positive studies have identified promising therapies for moderate TBI, the predictive validity of the model may be compromised when findings are translated to severely injured patients. Recently, the clinical relevance of LFP has been enhanced by combining the injury with secondary insults, as well as broadening studies to incorporate issues of gender and age to better approximate the range of human TBI within study design. We conclude that the LFP brain injury model is an appropriate tool to study the cellular and mechanistic aspects of human TBI that cannot be addressed in the clinical setting, as well as for the development and characterization of novel therapeutic interventions. Continued translation of pre-clinical findings to human TBI will enhance the predictive validity of the LFP model, and allow novel neuroprotective and neuroregenerative treatment strategies developed in the laboratory to reach the appropriate TBI patients.

The impact of age on traumatic brain injury

Older individuals with TBI differ from younger adults with TBI in several ways, including their incidence rates, etiology of injury, nature of complications, lengths of hospitalization, functional outcomes, and mortality. Despite the greater likelihood of poorer functional outcomes, older adults with TBI often achieve good functional outcomes and can live in community settings after receiving appropriate rehabilitation services, although at higher costs and longer hospitalizations than younger individuals. The future of rehabilitation care for elderly patients after TBI is uncertain due to financial limitations associated with the implementation of the PPS payment system by CMS. Little is known regarding the long-term impact of TBI on individuals as they age, but this is an important issue as the population ages.

Mortality from traumatic brain injury

It is the general sense that mortality has been decreasing in recent years compared to earlier studies described by the NIH traumatic coma data bank. We studied mortality during the period of 1984 to 1996 to determine if indeed mortality from severe traumatic brain injury was decreasing and to identify factors which might account for the reduction. The study population (N = 1839) consisted of severely head injured patients extracted retrospectively from the TCDB (635), MCV (382), and 822 patients from clinical trial databases conducted in the United States. Mortality was obtained from each of the databases for the age range form 16 to 65. Penetrating injury and treatment groups in the clinical trial databases were excluded. Mortality in the year 1984 equaled 39% and gradually decreased to a level of 27% in 1996. When adjusting for age, motor score and pupil reaction, the mortality of the period from 1984 to 1987 was significantly higher (p < 0.05) than that of the period 1988 to 1996. During the period 1984 through 1996, mortality from severe brain injury steadily declined. Factors other than age, motor score and pupil reactivity over time are responsible for this reduction. This reduction over time is an important factor for prognostic modeling of TBI.

[Prognostic factors in severe head injury]

The knowledge of the so called prognostic factors or indicators involved in severe head injury (SHI) is an issue of great interest to make predictions about the future of patients with this pathology. Those indicators constitute the basic elements of the different prognostic formulas or models carried out in order to make predictions in SHI. The mentioned models, therefore, will be constructed by a group of variables (prognostic indicators or factors) and several scales (prognostic scales) that are useful for measuring the final outcome of these patients. In this paper we resume, after an exhaustive review of the literature, the knowledge about the prognostic factors related to SHI. These indicators have been classified as follows: clinical, radiological, physiological, and biochemical. Moreover, we have briefly described the prognostic scales more commonly used in SHI.

The Effect of Age on Functional Outcome in Mild Traumatic Brain Injury: 6-Month Report of a Prospective Multicenter Trial

OBJECTIVE

Elderly patients (aged 60 years and older) have been demonstrated to have an increased mortality after isolated traumatic brain injury (TBI); however, the prognosis of those patients surviving their hospitalization is unknown. We hypothesized that surviving elderly patients would also have decreased functional outcome, and this study examined the functional outcome of patients with isolated TBI at discharge and at 6 months posthospitalization.

METHODS

This was a multicenter prospective study of all patients with isolated moderate to severe TBI defined as Head Abbreviated Injury Scale score of 3 with an Abbreviated Injury Scale score in any other body area of 1. Patients surviving to discharge gave their consent and were enrolled. Data collected included demographics, Glasgow Coma Scale (GCS) score at admission, and neurosurgical interventions. Outcome data included discharge disposition and Glasgow Outcome Scale score and modified Functional Independence Measure (FIM) score at discharge and at 6 months.

RESULTS

Two hundred thirty-five patients were enrolled, with 44 (19%) aged greater than or equal to 65 years. Mechanisms of injury were falls (34%), assaults (28%), motor vehicle collisions (14%), pedestrian (11%), and other (12%). Falls were more common in the older patients and assaults in the younger group. The mean admitting GCS score was 12.8 (95% confidence interval [CI], 12.4-13.3), with older patients having a higher mean GCS score, 14.1 (95% CI, 13.6-14.6) versus 12.5 (95% CI, 12.0-13.1; p = 0.03). There were no differences in the percentage of patients admitted to the intensive care unit or requiring neurosurgical intervention between younger and older patients. Because there were few elderly patients with low GCS scores who survived to discharge, outcome measures focused on those patients with GCS scores of 13 to 15. A greater percentage of elderly were discharged to rehabilitation (28% vs. 16%, p =0.08). The mean discharge FIM score was 10.4 (95% CI, 9.8-11.0) for the elderly versus 11.4 (95% CI, 11.1-11.7) for the young (p =0.001), with 68% elderly and 89% young discharged with total independent scores of 11 to 12. At 6 months, the difference narrowed, but the mean FIM score was still greater for the young group, 11.7 (95% CI, 11.6-11.9) versus 11.0 (95% CI, 10.6-11.4; p < 0.001).

CONCLUSION

Functional outcome after isolated mild TBI as measured by the Glasgow Outcome Scale and modified FIM is generally good to excellent for both elderly and younger patients. Older patients required more inpatient rehabilitation and lagged behind their younger counterparts but continued to recover and improve after discharge. Although there were statistically significant differences in the FIM score at both discharge and 6 months, the clinical importance of these small differences in the mean FIM score to the patient's quality of life is less clear. Measurable improvement in functional status during the first 6 months after injury is observed in both groups. Aggressive management and care of older patients with TBI is warranted, and efforts should be made to decrease inpatient mortality. Continued follow-up is ongoing to determine whether these outcomes persist at 12 months.

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.