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

Everyday Memory for Everyday Tasks: Prospective Memory as an Outcome Measure Following TBI in Older Adults

Traumatic brain injury in older adults is an increasing problem in our aging community. Traditional functional outcome measures, such as return to work or academic achievement, as used with younger samples following traumatic brain injury are of limited use for older people. Although challenging to assess reliably, evaluation of prospective memory is gradually being included in outcome assessments following traumatic brain injury in younger samples and may be a useful index of cognitive competence in everyday life when assessing older adults following traumatic brain injury.

What Are the Characteristics of Traumatic Brain Injury in Older Adults?

The Australian community is ageing; over the next 40 years, our population over the age of 65 years will double to around 23%, and this considerable increase in older adults means an increasing number of people will be at risk of sustaining trauma through falls or road traffic accidents. In contrast to the increasingly well-documented outcome literature on younger adults, very few studies have focused on older adults. Instead of assuming that outcomes posttraumatic brain injury (post-TBI) will follow similar patterns as in younger samples, there are several reasons to investigate older age recovery separately, and these issues will be discussed by reviewing some of the primary characteristics of older adults who experience traumatic brain injury.

Severely injured geriatric population: morbidity, mortality, and risk factors

BACKGROUND

With an increasing life expectancy and more active elderly population, management of geriatric trauma patients continues to evolve. The aim was to describe the mechanism and injuries of severely injured geriatric patients and to identify risk factors associated with mortality.

METHODS

The Trauma Registry at a Canadian Level I trauma center was queried for all trauma patients older than 65 years and injury severity score >15 from 2004 to 2006, resulting in a retrospective chart review of 276 patients. The data were subsequently analyzed using univariate and multivariate analysis.

RESULTS

Average age was 81.5 years (mean injury severity score of 25). Most common comorbid illness was hypertension (57.3%) and most frequent mechanism of injury was falls (72.3%). The overall mortality was comparable with the US National Trauma Data Bank (26.8% vs. 32.0%, confidence interval, 0.00-0.10). Geriatric patients requiring intubation, blood transfusions, or suffering from head, C-spine, or chest trauma had an increased likelihood of death. In-hospital respiratory, gastrointestinal, or infectious complications also had higher likelihood of death.

CONCLUSIONS

Falls continue to be the most frequent mechanism of injury in severely injured geriatric patients. Risk factors associated with a higher likelihood of death are identified. More research is needed to better understand this important and increasing group of trauma patients.

Prevalence of comorbidity and its association with traumatic brain injury and outcomes in older adults

The study aims were to examine the association between age, comorbidity, and cause of injury in older adults with traumatic brain injury (TBI); and to determine which comorbidities relate to mortality, length of stay, and functional outcome at hospital discharge, controlling for initial injury severity, age, and sex. A retrospective cohort study design was used; clinical and outcome trauma registry data were obtained for 196 adults 55 and older with TBI. The majority had at least one comorbid condition (e.g., hypertension, alcohol abuse). In-hospital mortality was 31%. Among the oldest-old, motor vehicle collisions and falls were significantly associated with specific chronic diseases. Prior myocardial infarction was significantly associated with an increased risk of in-hospital death. Injury Severity Score and Glasgow Coma Scale score were predictive of discharge function, but comorbidity did not add significantly to the model. Primary TBI prevention efforts in older adults must consider the impact of comorbidity and cause of injury, particularly in the oldest-old. Alcohol abuse is common in older adults with TBI; screening should be conducted and interventions developed to prevent future injury. Future study is warranted to understand the interplay between pathophysiology of comorbid disease and injury and how to best manage rehabilitation within the context of aging.

Age: is it all in the head? Factors influencing mortality in elderly patients with head injuries

BACKGROUND

Elderly patients, an increasing segment of the population, who sustain traumatic brain injury (TBI) are known to have worse outcomes, including higher mortality. This objective of this study was to examine the Crash Injury Research Engineering Network and to determine at what age motor vehicle crash fatalities from head injuries increased.

METHODS

The Crash Injury Research Engineering Network database was queried from 1996 to 2009. Study inclusion criteria were adult vehicle occupants with TBI, with an Abbreviated Injury Scale score ≥2. The age at which mortality increased was calculated. Patients younger and older than this cutoff age were compared to determine differences in crash characteristics. The determined cutoff age was compared with one found in a larger, population-based database.

RESULTS

There were 915 patients who met the study criteria. An increase in mortality was seen at age 60 years despite no difference in Injury Severity Score and a decrease in crash severity. Patients ≤60 years were more likely to have alcohol involved, to be in a rollover crash, and had higher crash speeds. Comparing the element of the crash attributed to the head injury, the patients >60 years were more likely to have struck the airbag, door, and seat. An analysis of the larger database revealed an increase in mortality at age 70 years.

CONCLUSIONS

There was a higher mortality secondary to head injuries in those older than 60 years involved in motor vehicle crashes. Improved safety measures in vehicle design may decrease the number of head injuries seen in the older population.

Modification of Glasgow Coma Scale criteria for injured elders

OBJECTIVES

An abnormal field Glasgow Coma Scale (GCS) score of ≤13 has been used in our emergency medical services (EMS) system to prompt transport to a trauma center. For elders, Ohio has recently adopted a GCS of ≤14 to prompt EMS transport to a trauma center, as older patients respond differently to trauma and may benefit from a different GCS threshold. This study sought to determine if a field GCS of 14 is an appropriate cutoff to initiate transport to a trauma center among injured elders.

METHODS

This was a retrospective, observational statewide analysis of injured patients ≥16 years old captured by the Ohio Trauma Registry from 2002 to 2007. Outcomes studied included mortality, traumatic brain injury (TBI), neurosurgical intervention, and endotracheal intubation (ETI). Multiple imputation was performed to account for missing data. Age-stratified sensitivity and specificity for proposed GCS cutoffs of 13 and 14 were calculated. A series of multivariate logistic regression models was then constructed using each outcome as a dependent variable. Independent variables included age, GCS score, sex, blood pressure, injury type, nontrauma center, race, ethnicity, and Injury Severity Score (ISS). Two separate analyses were performed. For each age group, odds ratios (ORs) of each outcome were calculated both for the decrease in GCS from 15 to 14 and for the decrease from 14 to 13. The group of elders with GCS 14 was then compared to adults with GCS 13.

RESULTS

A total of 52,412 study patients were identified. For a GCS cutoff of 13, sensitivity among elders for each outcome was >20% less than sensitivity for adults, and specificity was 5% to 10% greater. Increasing the GCS cutoff for elders to 14 resulted in improved sensitivity for all outcomes (approximately 10%), with a decline in specificity to values near that of adults with GCS 13. In the multivariate models for elders, mortality increased with a decrease in GCS both from 15 to 14 (OR = 1.40, 95% confidence interval [CI] = 1.07 to 1.83) and from GCS 14 to 13 (OR = 2.34, 95% CI = 1.57 to 3.52). In adults, mortality did not increase with the drop from GCS 15 to 14 (OR = 1.22, 95% CI = 0.88 to 1.71) or from GCS 14 to 13 (OR = 1.45, 95% CI = 0.91 to 2.30). When comparing elders with GCS 14 to adults with GCS 13, elders had greater odds of mortality (OR = 4.68, 95% CI = 2.90 to 7.54) and TBI (OR = 1.84, 95% CI = 1.45 to 2.34).

CONCLUSIONS

Changing the EMS trauma triage cutoff for elders from GCS 13 to GCS 14 results in improved sensitivity for clinically relevant outcomes. In injured elders, the decline in GCS from 15 to 14 is associated with increased mortality, a finding not observed in younger adults. Elders with GCS 14 have greater odds of mortality and TBI than adults with GCS 13. These results support recent changes in EMS trauma triage guidelines for elders adopted in Ohio.

Lower extracellular glucose level prolonged in elderly patients with severe traumatic brain injury: a microdialysis study

Age may be an independent predictor of outcomes in traumatic brain injury (TBI), but the causes of the poor outcomes in elderly patients remain unclear. To clarify the differences between elderly and young patients with TBI, brain metabolism parameters were monitored with the microdialysis method in 30 patients with severe TBI (Glasgow Coma Scale scores 3-8). The microdialysis probe was inserted in the penumbra area of the brain and extracellular levels of glucose, glutamate, glycerol, lactate, and pyruvate were measured hourly for the initial 168 hours (7 days) after operation. The lactate/pyruvate ratio, which is considered to be a good indicator of neuronal ischemia, was also calculated. The patients were divided into the elderly group aged 65 years or older and the young group aged less than 65 years, and the biochemical markers were compared daily between these two groups. The value of extracellular glucose concentration was significantly lower in the elderly group than in the young group, and continued until the 7th day after injury. Moreover, the lactate/pyruvate ratio peaked on the 5th day after injury in the elderly group, later than in the young group. We concluded that neural vulnerability persisted longer in elderly patients than in young patients with TBI, and this should be considered to prevent the occurrence of additional secondary brain injury.

Quality of life after traumatic brain injury: the clinical use of the QOLIBRI, a novel disease-specific instrument

OBJECTIVE

To report the clinical use of the QOLIBRI, a disease-specific measure of health-related quality-of-life (HRQoL) after traumatic brain injury (TBI).

METHODS

The QOLIBRI, with 37 items in six scales (cognition, self, daily life and autonomy, social relationships, emotions and physical problems) was completed by 795 patients in six languages (Finnish, German, Italian, French, English and Dutch). QOLIBRI scores were examined by variables likely to be influenced by rehabilitation interventions and included socio-demographic, functional outcome, health status and mental health variables.

RESULTS

The QOLIBRI was self-completed by 73% of participants and 27% completed it in interview. It was sensitive to areas of life amenable to intervention, such as accommodation, work participation, health status (including mental health) and functional outcome.

CONCLUSION

The QOLIBRI provides information about patient's subjective perception of his/her HRQoL which supplements clinical measures and measures of functional outcome. It can be applied across different populations and cultures. It allows the identification of personal needs, the prioritization of therapeutic goals and the evaluation of individual progress. It may also be useful in clinical trials and in longitudinal studies of TBI recovery.

Age-related mitochondrial changes after traumatic brain injury

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

Ambient experience in restitutive treatment of aphasia

One of the greatest challenges to language rehabilitation is reconciling the fact that the same therapeutic intervention, provided to different individuals with similar types of stroke-induced aphasia, may result in divergent outcomes. In this paper, the authors reviewed existing literature to identify relevant ambient factors – those outside the control of the clinician – that may potentially influence functional language recovery in aphasia and response to treatment. The goal was to develop a clinical history-taking tool to assist clinicians in gathering information germane to each individual's unique circumstances and environment, elements that may have previously been underestimated, to provide a complete inventory of potentially potent prognostic factors. First, two of the authors, speech–language pathologists experienced in aphasia rehabilitation, identified and categorized factors that seemed likely to influence aphasia outcomes. Then, a wide range of literature was reviewed in an effort to identify factors empirically found to be potent influences on aphasia recovery. Where studies relating these factors to aphasia were not found, relevant research from allied fields that examined recovery from brain injury is reported. Moreover, some factors thought to be potentially potent have yet to be examined. Finally, the ambient factors supported by evidence were categorized as facilitators or barriers to functional improvement, and the Ambient Influences on Outcome Checklist (AOC) was developed, including only those factors shown to be potent in the recovery process. It is hoped that this checklist can be used to more broadly assess potential prognostic influences in aphasia restitution, as well as spawn further research.

Prevalence of Epilepsy among Cataract Patients

PURPOSE

To evaluate the prevalence of epilepsy among patients undergoing cataract surgery.

DESIGN

A retrospective observational case control study.

METHODS

We calculated the prevalence of epilepsy among all the patients older than 50 years who underwent cataract surgery (years 2000-2007, n = 12,984) in a district of the largest health maintenance organization in Israel (the Central District of Clalit Health Services) and among 25,968 age and gender matched controls. The database was screened for epilepsy by integrating the clinical and ancillary work-up as well as the drug regimen. The use of anti-epileptic drugs (AEDs) was evaluated among the cataract patients and the controls. The main outcome measure was the prevalence of epilepsy and antiepileptic medical treatment among patients undergoing cataract surgery versus controls.

RESULTS

No difference was found in demographics among the groups including age, gender, marriage status, socioeconomic class and living place between the study and control groups (except for patients origin). Epilepsy was found to be significantly more prevalent in patients undergoing cataract surgery. The odds ratio (OR) was 1.3 (95% confidence interval (CI): 1.1-1.6): 1.4 in men (95% CI: 1.1-1.9) and 1.2 in women (95% CI: 1.0-1.6). AEDs, particularly clonazepam (OR = 1.5, 95% CI: 1.1-2.1) and carbamazepine (OR = 1.4, 95% CI: 1.05-1.8), were also used more by cataract patients. Multivariate logistic regression analysis revealed a significant association between cataract surgery and epilepsy (OR 1.26, p < 0.001) as well as diabetes (OR 1.38, p < 0.001), arterial hypertension (OR 1.26, p < 0.001), smoking (OR 1.22, p < 0.001), hyperlipidemia (OR 1.12, p < 0.001), and Ashkenazi origin (OR 0.85, p < 0.001).

CONCLUSIONS

Epilepsy is associated with the presence of cataract. Various hypotheses may explain this finding, including a cataractogenic role of AEDs.

Untreated mild traumatic brain injury in a young adult population

The current study was conducted to determine (a) the demographic and injury characteristics of individuals who did not receive treatment for mild brain injury and (b) the reasons these individuals do not receive or seek treatment. In a large sample of undergraduate students initially surveyed via an on-line questionnaire (n = 1,853), 35% of those who responded to a subsequent survey acknowledged that they had experienced at least one mild traumatic brain injury (TBI) for which they were not treated. Compared with those who were treated for each TBI, those who were untreated were more likely to be men and were less likely to report persisting symptoms 3 months after the injury. There were no differences in demographics or injury characteristics (e.g., length of time unconscious) between groups. Of those with an untreated TBI, the most common reasons for not seeking treatment were that the symptoms resolved quickly and that they were neither bothersome nor disruptive. Findings are discussed in terms of research on recovery from mild TBI.

Influence of sex and age on inpatient rehabilitation outcomes among older adults with traumatic brain injury

Graham JE, Radice-Neumann DM, Reistetter TA, Hammond FM, Dijkers M, Granger CV. Influence of sex and age on inpatient rehabilitation outcomes among older adults with traumatic brain injury.

OBJECTIVE

To assess the influence of sex and age on inpatient rehabilitation outcomes in a large national sample of older adults with traumatic brain injury (TBI).

DESIGN

Prospective case series.

SETTING

Eight hundred forty-eight inpatient rehabilitation facilities that subscribe to the Uniform Data System for Medical Rehabilitation.

PARTICIPANTS

Patients (n=18,413) age 65 years and older admitted for inpatient rehabilitation after TBI from 2005 through 2007.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Rehabilitation length of stay, discharge FIM motor and cognitive ratings, discharge setting, and scheduled home health services at discharge.

RESULTS

Mean age +/- SD of the sample was 79+/-7 years, and 47% were women. In multivariable models, higher age was associated with shorter lengths of stay (P<.001), lower discharge FIM motor and cognitive ratings (P<.001), and greater odds of home health services at discharge (P<.001). Women demonstrated shorter lengths of stay (P=.006) and greater odds of being scheduled for home health services at discharge (P<.001) than men. The sex-by-age interaction term was not significant in any outcome model. Sex differences and trends were consistent across the entire age range of the sample.

CONCLUSIONS

Sex and age patterns in rehabilitation outcomes among older adults with TBI varied by outcome. The current findings related to rehabilitation length of stay may be helpful for facility-level resource planning. Additional studies are warranted to identify the factors associated with returning to home and to assess the long-term benefits of combined inpatient rehabilitation and home health services for older adults with TBI.

Impaired expression of neuroprotective molecules in the HIF-1alpha pathway following traumatic brain injury in aged mice

Elderly traumatic brain injury (TBI) patients have higher rates of mortality and worse functional outcome than non-elderly TBI patients. The mechanisms involved in poor outcomes in the elderly are not well understood. Hypoxia-inducible factor-1 alpha (HIF-1alpha) is a basic helix-loop-helix transcription factor that modulates expression of key genes involved in neuroprotection. In this study, we studied the expression of HIF-1alpha and its target survival genes, heme oxygenase-1 (HO-1), vascular endothelial growth factor (VEGF), and erythropoietin (EPO) in the brains of adult versus aged mice following controlled cortical impact (CCI) injury. Adult (5-6 months) and aged (23-24 months) C57Bl/6 mice were injured using a CCI device. At 72 h post-injury, mice were sacrificed and the injured cortex was used for mRNA and protein analysis using real-time reverse transcription--polymerase chain reaction (RT-PCR) and Western blotting protocols. Following injury, HIF-1alpha, HO-1, and VEGF showed upregulation in both the young and aged mice, but in the aged animals the increase in HIF-1alpha and VEGF in response to injury was much lower than in the adult injured animals. EPO was upregulated in the adult injured brain, but not in the aged injured brain. These results support the hypothesis that reduced expression of genes in the HIF-1alpha neuroprotective pathway in aging may contribute to poor prognosis in the elderly following TBI.

Aging and animal models of systemic insult: trauma, burn, and sepsis

In the acute-care setting, it is widely accepted that elderly patients have increased morbidity and mortality compared with young healthy patients. The reasons for this, however, are largely unknown. Although animal modeling has helped improve treatment strategies for young patients, there are a scarce number of studies attempting to understand the mechanisms of systemic insults such as trauma, burn, and sepsis in aged individuals. This review aims to highlight the relevance of using animals to study the pathogenesis of these insults in the aged and, despite the deficiency of information, to summarize what is currently known in this field.

Depression in the elderly after traumatic brain injury: a systematic review

PRIMARY OBJECTIVE

To systematically review recent research published in peer-reviewed journals that focus on depression in the elderly with TBI. To better understand the prevalence of depression in the elderly after TBI and to note any differences or similarities between the elderly and their younger counterparts. Explore depression in the general elderly population and depression in the overall TBI population to better understand depression in the elderly after TBI.

METHODS AND PROCEDURES

MEDLINE and PsychINFO searches garnered one peer-reviewed English language article that met the following inclusion criteria: elderly participants with TBI, depression directly assessed and use of self-report measures and/or structured clinical interview.

MAIN OUTCOMES AND RESULTS

Prevalence of depression in the elderly range from 1.8-8.9% in community-residing elders to 25% in nursing homes and long-term care settings. Prevalence of depression in the overall TBI population ranges from 15.3-42%. Little research has been published on depression in the elderly following TBI, but the available research report a prevalence of 21-37%.

CONCLUSION

The presence of depression after TBI in the elderly has important implications for rehabilitation treatment. There is a great need for more research in this area requiring more stringent age markers and methodology.

Detrimental effects of aging on outcome from traumatic brain injury: a behavioral, magnetic resonance imaging, and histological study in mice

Considerable evidence indicates that outcomes from traumatic brain injury (TBI) are worse in the elderly, but there has been little preclinical research to explore potential mechanisms. In this study, we examined the age-related effects on outcome in a mouse model of controlled cortical impact (CCI) injury. We compared the responses of adult (5-6 months old) and aged (21-24 months old) male mice following a moderate lateral CCI injury to the sensorimotor cortex. Sensorimotor function was evaluated with the rotarod, gridwalk and spontaneous forelimb behavioral tests. Acute edema was assessed from hyperintensity on T2-weighted magnetic resonance images. Blood-brain barrier opening was measured using anti-mouse immunoglobulin G (IgG) immunohistochemistry. Neurodegeneration was assessed by amino-cupric silver staining, and lesion cavity volumes were measured from histological images. Indicators of injury were generally worse in the aged than the adult mice. Acute edema, measured at 24 and 48 h post-injury, resolved more slowly in the aged mice (p < 0.01). Rotarod recovery (p < 0.05) and gridwalk deficits (p < 0.01) were significantly worse in aged mice. There was greater (p < 0.01 at 3 days) and more prolonged post-acute opening of the blood-brain barrier in the aged mice. Neurodegeneration was greater in the aged mice (p < 0.01 at 3 days). In contrast, lesion cavity volumes, measured at 3 days post-injury, were not different between injured groups. These results suggest that following moderate controlled cortical impact injury, the aged brain is more vulnerable than the adult brain to neurodegeneration, resulting in greater loss of function. Tissue loss at the impact site does not explain the increased functional deficits seen in the aged animals. Prolonged acute edema, increased opening of the blood-brain barrier and increased neurodegeneration found in the aged animals implicate secondary processes in age-related differences in outcome.

The role of future longitudinal studies in ICU survivors: understanding determinants and pathophysiology of brain dysfunction

PURPOSE OF REVIEW

Recent investigations demonstrate that most critical care survivors face significant brain-related morbidity including neurocognitive deficits. While current data on neurocognitive outcomes after critical illness are intriguing, gaps in the literature far exceed what we have learned to date. In this paper, we examine important areas of investigation heretofore unaddressed and propose directions for clinically oriented outcomes research.

RECENT FINDINGS

Neurocognitive impairments after critical illness, which affect multiple cognitive domains, may improve during the first 12 months after ICU discharge but may persist in many patients for years. These impairments appear to be independent of traditional measures of severity of critical illness or age, and risk factors for and mechanisms of injury are currently being defined.

SUMMARY

Over the last decade, ICU-related cognitive impairment has been identified as a significant public health problem and has become the focus of intense investigation by researchers around the world. While substantial work has been done to date, vitally important questions remain. Future research should evaluate the mechanisms of and risk factors for brain injury, the natural history of neurocognitive dysfunction, structural and functional brain-imaging studies, and therapeutic modalities designed to prevent or decrease neuropsychological disability.

Geriatric Trauma

Elderly trauma patients present unique challenges and face more significant obstacles to recovery than younger patients. Despite overall higher mortality, longer length of stay, increased resource use, and higher rates of discharge to rehabilitation, most elderly trauma patients return to independent or preinjury functional status. Critical to improving these outcomes is an understanding that although similar trauma principles apply to the elderly, these patients require more aggressive evaluation and resuscitation. This article reviews the recent developments in the literature regarding care of the elderly trauma patient.