Prediction of recovery from traumatic brain injury

Impact of Sociodemographic, Premorbid, and Injury-Related Factors on Patient-Reported Outcome Trajectories after Traumatic Brain Injury (TBI)

Traumatic brain injury (TBI) remains one of the leading causes of death and disability worldwide. To better understand its impact on various outcome domains, this study pursues the following: (1) longitudinal outcome assessments at three, six, and twelve months post-injury; (2) an evaluation of sociodemographic, premorbid, and injury-related factors, and functional recovery contributing to worsening or improving outcomes after TBI. Using patient-reported outcome measures, recuperation trends after TBI were identified by applying Multivariate Latent Class Mixed Models (MLCMM). Instruments were grouped into TBI-specific and generic health-related quality of life (HRQoL; QOLIBRI-OS, SF-12v2), and psychological and post-concussion symptoms (GAD-7, PHQ-9, PCL-5, RPQ). Multinomial logistic regressions were carried out to identify contributing factors. For both outcome sets, the four-class solution provided the best match between goodness of fit indices and meaningful clinical interpretability. Both models revealed similar trajectory classes: stable good health status (HRQoL: n = 1944; symptoms: n = 1963), persistent health impairments (HRQoL: n = 442; symptoms: n = 179), improving health status (HRQoL: n = 83; symptoms: n = 243), and deteriorating health status (HRQoL: n = 86; symptoms: n = 170). Compared to individuals with stable good health status, the other groups were more likely to have a lower functional recovery status at three months after TBI (i.e., the GOSE), psychological problems, and a lower educational attainment. Outcome trajectories after TBI show clearly distinguishable patterns which are reproducible across different measures. Individuals characterized by persistent health impairments and deterioration require special attention and long-term clinical monitoring and therapy.

The Effect of Oral Mucosal Mesenchymal Stem Cells on Pathological and Long-Term Outcomes in Experimental Traumatic Brain Injury

Background

Neuroprotective effects of stem cells have been shown in some neurologic diseases. In this study, the effect of oral mucosal mesenchymal stem cells (OMSCs) on traumatic brain injury (TBI) was evaluated in long term.

Materials and Methods

TBI was induced by Marmarou's method. The number of 2 × 10⁶ OMSCs was intravenously injected 1 and 24 h after the injury. Brain edema and pathological outcome were assessed at 24 h and 21 days after the injury. Besides, long-term neurological, motor, and cognitive outcomes were evaluated at days 3, 7, 14, and 21 after the injury.

Results

OMSCs administration could significantly inhibit microglia proliferation, and reduce brain edema and neuronal damage, at 24 h and 21 days after the injury. Neurological function improvement was observed in the times evaluated in OMSCs group. Cognitive and motor function dysfunction and anxiety-like behavior were prevented especially at 14 and 21 days after the injury in the treatment group.

Conclusion

According to the results of this study, OMSCs administration after TBI reduced brain edema and neuronal damage, improved neurologic outcome, and prevented memory and motor impairments and anxiety-like behavior in long term.

Acquired Brain Injury in Adults: A Review of Pathophysiology, Recovery, and Rehabilitation

Purpose

To summarize existing literature from a range of fields (i.e., neurology, neuropsychology, neuroscience, neuroimaging, rehabilitation, speech-language pathology) that is relevant to the development and/or revision of cognitive rehabilitation programs for individuals with acquired brain injury (ABI) and in particular, for young adults.

Method

This paper reviews a range of ABI-associated topics including: 1) mechanisms of injury; 2) biological, individual-specific, and behavioral drivers of recovery; and 3) current methods of cognitive rehabilitation. It then narrows focus to young adults, a frequently affected and growing population to sustain ABI. The paper concludes by providing: 1) suggestions for key components of cognitive rehabilitation for young adults with ABI; 2) an example from our own research providing intensive academically-focused cognitive rehabilitation for young adults with ABI pursuing college; and 3) recommendations for future behavioral and neuroimaging studies in this area.

Conclusions

ABI is on the rise in the United States. Young adults have been sustaining ABI at higher rates over the past several decades. These injuries occur when they would otherwise be advancing their academic and career goals, making the cognitive deficits that often accompany ABI especially devastating for this group. Review of existing literature suggests cognitive rehabilitation programs that combine aspects of restorative, comprehensive, and contextualized approaches could promote recovery for young adults with ABI. Future intervention studies may benefit from including both behavioral and neural outcomes to best understand how principles of neuroplasticity- naturally embedded within many cognitive rehabilitation approaches-could be manipulated to promote cognitive recovery and long-lasting brain reorganization in this group.

Cumulative Influence of Inflammatory Response Genetic Variation on Long-Term Neurobehavioral Outcomes after Pediatric Traumatic Brain Injury Relative to Orthopedic Injury: An Exploratory Polygenic Risk Score

The addition of genetic factors to prognostic models of neurobehavioral recovery following pediatric traumatic brain injury (TBI) may account for unexplained heterogeneity in outcomes. The present study examined the cumulative influence of candidate genes involved in the inflammatory response on long-term neurobehavioral recovery in children with early childhood TBI relative to children with orthopedic injuries (OI). Participants were drawn from a prospective, longitudinal study evaluating outcomes of children who sustained TBI (n = 67) or OI (n = 68) between the ages of 3 and 7 years. Parents completed ratings of child executive function and behavior at an average of 6.8 years after injury. Exploratory unweighted and weighted polygenic risk scores (PRS) were constructed from single nucleotide polymorphisms (SNPs) across candidate inflammatory response genes (i.e., angiotensin converting enzyme [ACE], brain-derived neurotrophic factor [BDNF], interleukin-1 receptor antagonist [IL1RN], and 5'-ectonucleotidase [NT5E]) that showed nominal (p ≤ 0.20) associations with outcomes in the TBI group. Linear regression models tested the PRS × injury group (TBI vs. OI) interaction term and post-hoc analyses examined the effect of PRS within each injury group. Higher inflammatory response PRS were associated with more executive dysfunction and behavior problems in children with TBI but not in children with OI. The cumulative influence of inflammatory response genes as measured by PRS explained additional variance in long-term neurobehavioral outcomes, over and above well-established predictors and single candidate SNPs tested individually. The results suggest that some of the unexplained heterogeneity in long-term neurobehavioral outcomes following pediatric TBI may be attributable to a child's genetic predisposition to a greater or lesser inflammatory response to TBI.

The Long Run: Neuroprotective Effects of Physical Exercise on Adult Neurogenesis from Youth to Old Age

BACKGROUND

The rapid lengthening of life expectancy has raised the problem of providing social programs to counteract the age-related cognitive decline in a growing number of older people. Physical activity stands among the most promising interventions aimed at brain wellbeing, because of its effective neuroprotective action and low social cost. The purpose of this review is to describe the neuroprotective role exerted by physical activity in different life stages. In particular, we focus on adult neurogenesis, a process which has proved being highly responsive to physical exercise and may represent a major factor of brain health over the lifespan.

METHODS

The most recent literature related to the subject has been reviewed. The text has been divided into three main sections, addressing the effects of physical exercise during childhood/ adolescence, adulthood and aging, respectively. For each one, the most relevant studies, carried out on both human participants and rodent models, have been described.

RESULTS

The data reviewed converge in indicating that physical activity exerts a positive effect on brain functioning throughout the lifespan. However, uncertainty remains about the magnitude of the effect and its biological underpinnings. Cellular and synaptic plasticity provided by adult neurogenesis are highly probable mediators, but the mechanism for their action has yet to be conclusively established.

CONCLUSION

Despite alternative mechanisms of action are currently debated, age-appropriate physical activity programs may constitute a large-scale, relatively inexpensive and powerful approach to dampen the individual and social impact of age-related cognitive decline.

Correlation of arterial blood gas markers and lactate levels with outcomes in pediatric traumatic brain injury

Background:

Various physical markers have been used to predict outcome of traumatic brain injury in children. However, the utility of metabolic alterations for prognostication has been poorly described. Thus, we aim to correlate arterial blood gas markers and lactate levels with outcomes in children with moderate to severe traumatic brain injury.

Methods:

This is a retrospective cohort study that included all patients <16 years old who presented to the Emergency Department with moderate to severe traumatic brain injury (Glasgow Coma Scale ⩽13). Serial arterial blood gas results and lactate levels in the first five days of admission to a pediatric intensive care unit (PICU) were reviewed. Primary outcome was in-hospital mortality. Secondary outcomes were 28-day ventilator-free and PICU-free days. A stepwise logistic regression analysis in conjunction with receiver operating characteristic analysis were used to identify variables that were associated with in-hospital mortality. Secondary outcomes were analyzed using multiple linear regression.

Results:

Among the 43 patients analyzed, more than half of the patients (60%) had severe traumatic brain injury (Glasgow Coma Scale 8). Twenty-seven of the 43 (65%) patients underwent neurosurgical intervention and overall mortality was 9/43 (20.9%). The worst base excess and lactate levels of Day 2 of PICU stay were found to be most predictive for mortality with maximal area-under-curve (95% confidence interval) of 0.967 (0.906, 1.000). Worst lactate level on day 2 of PICU stay was also found to be associated with ventilator-free days and PICU-free days.

Conclusion:

In children with moderate to severe traumatic brain injury, base excess and lactate on Day 2 of PICU stay were predictors of mortality, duration of mechanical ventilation and length of PICU stay.

Effects of concussion on the blood-brain barrier in humans and rodents

Traumatic brain injury and the long-term consequences of repeated concussions constitute mounting concerns in the United States, with 5.3 million individuals living with a traumatic brain injury-related disability. Attempts to understand mechanisms and possible therapeutic approaches to alleviate the consequences of repeat mild concussions or traumatic brain injury on cerebral vasculature depend on several aspects of the trauma, including: (1) the physical characteristics of trauma or insult that result in damage; (2) the time “window” after trauma in which neuropathological features develop; (3) methods to detect possible breakdown of the blood–brain barrier; and (4) understanding different consequences of a single concussion as compared with multiple concussions. We review the literature to summarize the current understanding of blood–brain barrier and endothelial cell changes post-neurotrauma in concussions and mild traumatic brain injury. Attention is focused on concussion and traumatic brain injury in humans, with a goal of pointing out the gaps in our knowledge and how studies of rodent model systems of concussion may help in filling these gaps. Specifically, we focus on disruptions that concussion causes to the blood–brain barrier and its multifaceted consequences. Importantly, the magnitude of post-concussion blood–brain barrier dysfunction may influence the time course and extent of neuronal recovery; hence, we include in this review comparisons of more severe traumatic brain injury to concussion where appropriate. Finally, we address the important, and still unresolved, issue of how best to detect possible breakdown in the blood–brain barrier following neurotrauma by exploring intravascular tracer injection in animal models to examine leakage into the brain parenchyma.

Global Outcome and Late Seizures After Penetrating Versus Closed Traumatic Brain Injury: A NIDRR TBI Model Systems Study

BACKGROUND

If and how much dural penetration influences long-term outcome after traumatic brain injury (TBI) is understudied, especially within the civilian population.

OBJECTIVES

Using the large TBI Model Systems cohort, this study assessed and compared penetrating TBI (PTBI) and closed TBI with respect to global outcome and late seizures 2 years after injury.

METHODS

After performing unadjusted PTBI versus closed TBI comparisons, multivariate regression models were built and analyzed for both outcomes by including the following additional predictors: length of unconsciousness, posttraumatic amnesia duration, hospital length of stay, age, gender, race, marital status, education level, problem substance abuse, and preinjury employment status.

RESULTS

The collapsed Glasgow Outcome Scale model (n = 6111) showed significant secondary effects of PTBI with employment status. When employed before injury, individuals with PTBI were 2.62 times more likely (95% confidence interval, 1.92-3.57) to have a lower Glasgow Outcome Scale category. The final model for late seizures (n = 6737) showed a significant main effect for PTBI. Adjusting for other predictors, individuals with PTBI were 2.78 times more likely (95% confidence interval, 1.93-3.99) than those with closed TBI to be rehospitalized for a seizure.

CONCLUSION

This study empirically demonstrates that penetrating injury mechanism has important prognostic implications.

Medical comorbidities in disorders of consciousness patients and their association with functional outcomes

OBJECTIVE

To identify, for patients in states of seriously impaired consciousness, comorbid conditions present during inpatient rehabilitation and their association with function at 1 year.

DESIGN

Abstracted data from a prospective cross-sectional observational study with data collection occurring January 1996 through December 2007.

SETTING

Four inpatient rehabilitation facilities in metropolitan areas.

PARTICIPANTS

The study sample of 68 participants is abstracted from a database of 157 patients remaining in states of seriously impaired consciousness for at least 28 days.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

One-year cognitive, motor, and total FIM score.

RESULTS

The most common medical complications during inpatient rehabilitation for the study sample are active seizures (46%), spasticity (57%), urinary tract infections (47%), and hydrocephalus with and without shunt (38%). Presence of ≥3 medical complications during inpatient rehabilitation, controlling for injury severity, is significantly (P<.05) associated with poorer total FIM and FIM motor scores 1 year after injury. The presence of hydrocephalus with and without shunt (r=-.20, -.21, -.18; P ≤.15), active seizures (r=-.31, -.22, -.42), spasticity (r=-.38, -.28, -.40), and urinary tract infections (r=-.25, -.24, -.26) were significantly (P<.10) associated with total FIM, FIM cognitive, and FIM motor scores, respectively.

CONCLUSIONS

Reported findings indicate that persons in states of seriously impaired consciousness with higher numbers of medical complications during inpatient rehabilitation are more likely to have lower functional levels 1-year postinjury. The findings indicate that persons with ≥3 medical complications during inpatient rehabilitation are at a higher risk for poorer functional outcomes at 1 year. It is, therefore, prudent to evaluate these patients for indications of these complications during inpatient rehabilitation.

Project VALOR: design and methods of a longitudinal registry of post-traumatic stress disorder (PTSD) in combat-exposed veterans in the Afghanistan and Iraqi military theaters of operations

Few studies have investigated the natural history of post-traumatic stress disorder (PTSD). Project VALOR (Veterans' After-discharge Longitudinal Registry) was designed as a longitudinal patient registry assessing the course of combat-related PTSD among 1600 male and female Veterans who served in Operation Enduring Freedom (OEF) in Afghanistan or Operation Iraqi Freedom (OIF). Aims of the study include investigating patterns and predictors of progression or remission of PTSD and treatment utilization. The study design was based on recommendations from the Agency for Healthcare Quality and Research for longitudinal disease registries and used a pre-specified theoretical model to select the measurement domains for data collection and interpretation of forthcoming results. The registry will include 1200 male and female Veterans with a recent diagnosis of PTSD in the Department of Veteran Affairs (VA) electronic medical record and a comparison group of 400 Veterans without a medical record-based PTSD diagnosis, to also allow for case-control analyses. Data are collected from administrative databases, electronic medical records, a self-administered questionnaire, and a semi-structured diagnostic telephone interview. Project VALOR is a unique and timely registry study that will evaluate the clinical course of PTSD, psychosocial correlates, and health outcomes in a carefully selected cohort of returning OEF/OIF Veterans.

Brain and spinal cord interaction: a dietary curcumin derivative counteracts locomotor and cognitive deficits after brain trauma

BACKGROUND

In addition to cognitive dysfunction, locomotor deficits are prevalent in traumatic brain injured (TBI) patients; however, it is unclear how a concussive injury can affect spinal cord centers. Moreover, there are no current efficient treatments that can counteract the broad pathology associated with TBI.

OBJECTIVE

The authors have investigated potential molecular basis for the disruptive effects of TBI on spinal cord and hippocampus and the neuroprotection of a curcumin derivative to reduce the effects of experimental TBI.

METHODS

The authors performed fluid percussion injury (FPI) and then rats were exposed to dietary supplementation of the curcumin derivative (CNB-001; 500 ppm). The curry spice curcumin has protective capacity in animal models of neurodegenerative diseases, and the curcumin derivative has enhanced brain absorption and biological activity.

RESULTS

The results show that FPI in rats, in addition to reducing learning ability, reduced locomotor performance. Behavioral deficits were accompanied by reductions in molecular systems important for synaptic plasticity underlying behavioral plasticity in the brain and spinal cord. The post-TBI dietary supplementation of the curcumin derivative normalized levels of BDNF, and its downstream effectors on synaptic plasticity (CREB, synapsin I) and neuronal signaling (CaMKII), as well as levels of oxidative stress-related molecules (SOD, Sir2).

CONCLUSIONS

These studies define a mechanism by which TBI can compromise centers related to cognitive processing and locomotion. The findings also show the influence of the curcumin derivative on synaptic plasticity events in the brain and spinal cord and emphasize the therapeutic potential of this noninvasive dietary intervention for TBI.

Injury-related production of cysteinyl leukotrienes contributes to brain damage following experimental traumatic brain injury

The leukotrienes belong to a family of biologically active lipids derived from arachidonate that are often involved in inflammatory responses. In the central nervous system, a group of leukotrienes, known as the cysteinyl leukotrienes, is generated in brain tissue in response to a variety of acute brain injuries. Although the exact clinical significance of this excess production remains unclear, the cysteinyl leukotrienes may contribute to injury-related disruption of the brain-blood barrier and exacerbate secondary injury processes. In the present study, the formation and role of cysteinyl leukotrienes was explored in the fluid percussion injury model of traumatic brain injury in rats. The results showed that levels of the cysteinyl leukotrienes were elevated after fluid percussion injury with a maximal formation 1 hour after the injury. Neutrophils contributed to cysteinyl leukotriene formation in the injured brain hemisphere, potentially through a transcellular biosynthetic mechanism. Furthermore, pharmacological reduction of cysteinyl leukotriene formation after the injury, using MK-886, resulted in reduction of brain lesion volumes, suggesting that the cysteinyl leukotrienes play an important role in traumatic brain injury.

Assessing reproductive status/stages in mice

The short reproductive cycle length observed in rodents, called the estrous cycle, makes them an ideal animal model for investigation of changes that occur during the reproductive cycle. Most of the data in the literature about the estrous cycle is obtained from rats because they are easily manipulated and they exhibit a clear and well-defined estrous cycle. However, the increased number of experiments using knockout mice requires identification of their estrous cycle as well, since (in)fertility issues may arise. In mice, like rats, the identification of the stage of estrous cycle is based on the proportion of cell types observed in the vaginal secretion. The aim of this unit is to provide guidelines for quickly and accurately determining estrous cycle phases in mice.

Traumatic brain injury in young children: postacute effects on cognitive and school readiness skills

Previous studies have documented weaknesses in cognitive ability and early academic readiness in young children with traumatic brain injury (TBI). However, few of these studies have rigorously controlled for demographic characteristics, examined the effects of TBI severity on a wide range of skills, or explored moderating influences of environmental factors on outcomes. To meet these objectives, each of three groups of children with TBI (20 with severe, 64 with moderate, and 15 with mild) were compared with a group of 117 children with orthopedic injuries (OI group). The children were hospitalized for their injuries between 3 and 6 years of age and were assessed an average of 1 1/2 months post injury. Analysis revealed generalized weaknesses in cognitive and school readiness skills in the severe TBI group and less pervasive effects of moderate TBI. Indices of TBI severity predicted outcomes within the TBI sample and environmental factors moderated the effects of TBI on some measures. The findings document adverse effects of TBI in early childhood on postacute cognitive and school readiness skills and indicate that these effects are related to both injury severity and the family environment.

Examining lactate in severe TBI using proton magnetic resonance spectroscopy

PRIMARY OBJECTIVE

Clinical management of acute traumatic brain injury (TBI) has emphasized identification of secondary mechanisms of pathophysiology. An important objective in this study is to use proton magnetic resonance spectroscopy (pMRS) to examine early metabolic disturbance due to TBI.

RESEARCH DESIGN

The current design is a case study with repeated measures.

METHOD AND PROCEDURE

Proton magnetic resonance imaging was used to examine neurometabolism in this case of very severe brain trauma at 9 and 23 days post-injury. MRI was performed on a clinical 1.5 Tesla scanner.

MAIN OUTCOMES AND RESULTS

These data also reveal that pMRS methods can detect lactate elevations in an adult surviving severe head trauma and are sensitive to changes in basic neurometabolism during the first month of recovery.

CONCLUSIONS

The current case study demonstrates the sensitivity of pMRS in detecting metabolic alterations during the acute recovery period. The case study reveals that lactate elevations may be apparent for weeks after severe neurotrauma. Further work in this area should endeavour to determine the ideal time periods for pMRS examination in severe TBI as well as the ideal locations of data acquisition (e.g. adjacent or distal to lesion sites).

[Prognostic capacity of brain herniation signs in patients with structural neurological injury]

OBJECTIVE

To determine whether the usual mortality prediction systems (APACHE and SAPS) can be complemented by cranial computed tomography (CT) brain herniation findings in patients with structural neurological involvement.

DESIGN

Prospective cohort study.

SETTING

Trauma ICU in university hospital.

PATIENTS

One hundred and fifty five patients admitted to ICU in 2003 with cranial trauma or acute stroke.

MAIN VARIABLES OF INTEREST

Data were collected on age, diagnosis, mortality, admission cranial CT findings and on APACHE II, APACHE III and SAPS II scores.

RESULTS

Mean age was 47.8 +/- 19.4 years; APACHE II, 17.1 +/- 7.2 points; SAPS II, 43.7 +/- 17.7 points; and APACHE III, 55.8 +/- 29.7 points. Hospital mortality was 36% and mortality predicted by SAPS II was 38%, by APACHE II 30% and by APACHE III 36%. The 56 non-survivors showed greater midline shift on cranial CT scan versus survivors (4.2 +/- 5.5 vs. 1.6 +/- 3.22 mm, p = 0.002) and higher severity as assessed by SAPS II, APACHE II and APACHE III. The mortality rate was significantly higher in patients with subfalcial herniation (61% vs. 30%, p < 0.001). In the multivariate logistic regression analysis, hospital mortality was associated with the likelihood of death according to APACHE III (OR 1.07; 95% CI: 1.05-1.09) and with presence of subfalcial herniation (OR 3.15; 95% CI: 1.07-9.25).

CONCLUSIONS

In critical care patients with structural neurological involvement, cranial CT signs of subfalcial herniation complement the prognostic information given by the usual severity indexes.

The Mayo Classification System for Traumatic Brain Injury Severity

PURPOSE

To develop a single TBI severity classification system based on commonly used TBI severity measures and indicators that (1) maximally uses available positive evidence to classify TBI severity in three categories: (a) Moderate-Severe (Definite) TBI, (b) Mild (Probable) TBI, (c) Symptomatic (Possible) TBI; (2) reflects current clinical knowledge and relevance; and (3) classifies a larger number of cases than single indicator systems with reasonable accuracy.

MAIN FINDINGS

The study sample of a defined population consisted of 1501 unique Olmsted County residents with at least one confirmed TBI event from 1985 to 1999. Within the sample, 1678 TBI events were confirmed. Single measures of TBI severity were not available in a large percentage of these events, i.e., Glasgow Coma Scale (GCS) was absent in 1242 (74.0%); loss of consciousness, absent in 178 (70.2%), posttraumatic amnesia (PTA), absent in 974 (58.1%), head CT, not done in 827 (49.3%). The Mayo Classification System for TBI Severity was developed to classify cases based on available indicators that included death due to TBI, trauma-related neuroimaging abnormalities, GCS, PTA, loss of consciousness and specified post-concussive symptoms. Using the Mayo system, all cases were classified. For the Moderate-Severe (Definite) TBI classification, estimated sensitivity was 89% and estimated specificity was 98%.

CONCLUSIONS

By maximally using relevant available positive evidence, the Mayo system classifies a larger number of cases than single indicator systems with reasonable accuracy. This system may be of use in retrospective research and for determination of TBI severity for planning postacute clinical care.

The influence of neuropathology on the FMRI signal: a measurement of brain or vein?

There is a rapidly growing literature using fMRI technology to investigate the various forms of behavioral impairment associated with brain injury and disease. Given this, surprisingly little work has been conducted to examine the influence of neuropathophysiological processes on the fMRI signal. This paper reviews the literature examining baseline alteration in cerebrovascular parameters associated with normal aging, brain injury, and brain disease. In addition, findings from three cases of individuals with severe brain trauma will be presented to show the influence of brain trauma on baseline cerebrovascular parameters measured by fMRI. The methods used here can be implemented by other investigators to accurately isolate specific hemodynamic changes that can influence the BOLD fMRI signal.

Multimodality comparison of neuroimaging in pediatric traumatic brain injury

Traumatic brain injury is a common cause of death and disability in children; early neuroimaging has assumed an increasingly important role in evaluating the extent and severity of injury. Several imaging methods were assessed in a study of 40 children with traumatic brain injury: computed tomography (CT), T(2)-weighted magnetic resonance imaging (MRI), fluid-attenuated inversion recovery (FLAIR) MRI, and susceptibility-weighted imaging (SWI) MRI to determine which were most valuable in predicting 6-12 month outcomes as classified by the Pediatric Cerebral Performance Category Scale score. Patients were subdivided into three groups: (1) normal, (2) mild disability, and (3) moderate/severe disability/persistent vegetative state. T(2), FLAIR, and SWI showed no significant difference in lesion volume between normal and mild outcome groups, but did indicate significant differences between normal and poor and between mild and poor outcome groups. Computed tomography revealed no significant differences in lesion volume between any groups. The findings suggest that T(2), FLAIR, and SWI MRI sequences provide a more accurate assessment of injury severity and detection of outcome-influencing lesions than does CT in pediatric traumatic brain injury patients. Although CT was inconsistent at lesion detection/outcome prediction, it remains an essential part of the acute traumatic brain injury work-up to assess the need for neurosurgic intervention.

Polyamine and aminoguanidine treatments to promote structural and functional recovery in the adult mammalian brain after injury: a brief literature review and preliminary data about their combined administration

The regeneration potential of the adult mammalian central nervous system (CNS) is very modest, due to, among other factors, the presence of either a glial scar, or myelin-associated regeneration inhibitors such as Nogo-A, MAG and OMgp, which all interact with the same receptor (NgR). After a brief review of the key proteins (Rho and PKC) implicated in NgR-mediated signalling cascades, we will tackle the implications of cAMP and Arginase I in overcoming myelin growth-inhibitory influence, and then will focus on the effects of polyamines and aminoguanidine to propose (and to briefly support this proposal by our own preliminary data) that their association might be a potent way to enable functionally-relevant regeneration in the adult mammalian CNS.

Lebenszufriedenheit von Menschen nach schwersten Hirnschädigungen

Zusammenfassung. Um die langfristigen Auswirkungen schwerer Hirnschädigungen zu untersuchen, wurden bei 135 ehemaligen Patienten einer neurologischen Frührehabilitation Angaben zum funktionellen und psychosozialen Outcome sowie zur Lebenszufriedenheit erhoben. Die querschnittlich angelegte Fragebogenuntersuchung erfolgte durchschnittlich 3.5 Jahre nach der Erkrankung. In basalen Aktivitäten des täglichen Lebens konnte mehr als die Hälfte der früheren Patienten eine weitgehende Selbstständigkeit wiedererlangen, in komplexen Alltagstätigkeiten und kognitiven Leistungsbereichen bestanden deutlichere Einschränkungen. Über 60 % der Teilnehmer waren unabhängig von professioneller Pflege, über 80 % wohnten wieder in einem häuslichen Umfeld. Scheidungen waren selten. Eine Rückkehr in den Beruf gelang ca. 23 % der Teilnehmer. Die Lebenszufriedenheit unterschied sich mit Ausnahme der gesundheitsbezogenen Lebenszufriedenheit nicht von der bundesdeutschen Durchschnittsbevölkerung. Die Ergebnisse zeigen, dass die untersuchten Patienten trotz bestehender Defizite ihre Lebenssituation weitgehend positiv bewerten.

Update of neuropathology and neurological recovery after traumatic brain injury

This review focuses on the potential for traumatic brain injury to evoke both focal and diffuse changes within the brain parenchyma, while considering the cellular constituents involved and the subcellular perturbations that contribute to their dysfunction. New insight is provided on the pathobiology of traumatically induced cell body injury and diffuse axonal damage. The consequences of axonal damage in terms of subsequent deafferentation and any potential retrograde cell death and atrophy are addressed. The regional and global metabolic sequelae are also considered. This detailed presentation of the neuropathological consequences of traumatic brain injury is used to set the stage for better appreciating the neurological recovery occurring after traumatic injury. Although the pathological and clinical effects of focal and diffuse damage are usually intermingled, the different clinical manifestations of recovery patterns associated with focal versus diffuse injuries are presented. The recognizable patterns of recovery, involving unconsciousness, posttraumatic confusion/amnesia, and postconfusional restoration, that typically occur across the full spectrum of diffuse injury are described, recognizing that the patient's long-term recovery may involve more idiosyncratic combinations of dysfunction. The review highlights the relationship of focal lesions to localizing syndromes that may be embedded in the evolving natural history of diffuse pathology. It is noted that injuries with primarily focal pathology do not necessarily follow a comparable pattern of recovery with distinct phases. Potential linkages of these recovery patterns to the known neuropathological sequelae of injury and various reparative mechanisms are considered and it is proposed that potential biological markers and newer imaging technologies will better define these linkages.

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.

Preservation of neurological functions by nitric oxide synthase inhibitors in conscious rats following delayed hemorrhagic shock

Excessive production of nitric oxide (NO) as result of inducible nitric oxide synthase (iNOS) induction has been implicated in the pathophysiology of hemorrhagic shock. Our aim was to study the effects of NOS inhibitors, aminoguanidine (AG) and NG-nitro-L-arginine methyl ester (L-NAME), on survival rate, mean arterial blood pressure (MABP), temporal evolution of infarct volume, nitric oxide (NO) production and neurological deficit in a model of delayed hemorrhagic shock (DHS) in conscious rats. Our results showed that the NOS inhibitors significantly improved survival rate, MABP, and attenuated brain NO overproduction 24, 48 h and 72 h after DHS. AG reduced brain infarct volume and improved the neurological performance evaluated by the rotameric and grip strength tests while L-NAME did not show protective effect in rats following DHS. These findings suggest that NO formation via iNOS activation may contribute to organ damage and that the selective iNOS inhibitor, AG, may be of interest as a therapeutic agent for neurological recovery following DHS.

Neuropsychological outcome of infant heart transplant recipients

OBJECTIVE

To assess long-term neuropsychological outcomes of infant heart transplant recipients.

STUDY DESIGN

Fifty-five children (mean age, 6.4 years) with a primary diagnosis of hypoplastic left heart syndrome or other cardiac disorders participated in the study. Six areas of risk were assessed (birth; preoperative, intraoperative, and postoperative status; long-term medical complications; and socioeconomic factors). Neuropsychological evaluations included the following: Wechsler Scales of Intelligence, Wechsler Individual Achievement Test, Berry Visual Motor Integration Scale, Comprehensive Evaluation of Language Function, and Achenbach Child Behavioral Checklist.

RESULTS

Intellectual functioning scores revealed a mean full-scale IQ of 81 +/- 19. Intraoperative and postoperative variables (bypass time, hospital course, and lowest posttransplant pH), long-term medical complications (serious infections and posttransplant surgical procedures), and socioeconomic factors were associated with cognitive functioning. Visual-motor functioning was also related to bypass and total support time.

CONCLUSIONS

Long-term outcomes reveal low-average neuropsychological functioning and are related to intrasurgical-postsurgical, long-term medical, and socioeconomic factors. The neuropsychological and psychosocial functioning of infant heart transplant recipients will be important to address as they mature during adolescence and adulthood.

Retrospective assessment of rehabilitation outcome after traumatic brain injury: development and utility of the functional independence level

OBJECTIVE

To develop a measure suitable for retrospective analysis of qualitative brain injury outcome data, the Functional Independence Level (FIL), and document its reliability, validity, and utility.

DESIGN

Retrospective analysis of existing records, with inclusion based on availability of records, and quantitative or qualitative documentation of functional status at a minimum of 1.5 years after injury.

SETTING

Statewide acute and postacute rehabilitation facilities, as part of a State Head Injury Program.

PARTICIPANTS

A total of 338 individuals, with documented moderate to severe traumatic brain injury; primarily males ages 16 to 45.

MAIN OUTCOME MEASURES

Disability Rating Scale (DRS) at discharge from primary rehabilitation, Living Situation and Functional Independence Level coded from information in postacute rehabilitation reports, at an average of approximately 6 years after injury.

RESULTS

Inter-rater reliability coefficients for FIL ratings extracted from rehabilitation records, and between retrospective and in vivo assessments were highly significant. DRS scores at discharge from primary rehabilitation predicted a significant amount of variance in FIL scores at an average of 5 years after injury, and DRS scores remained a stable and significant predictor of FIL scores as the time period between discharge from rehabilitation and outcome ratings increased to 10 years after injury. FIL ratings were significantly lower for individuals living in residential facilities than those living with their families, as compared to living alone.

CONCLUSIONS

The FIL is a reliable and useful tool for retrospective and prospective assessments of rehabilitation outcome. Gains made during primary rehabilitation by people with severe traumatic brain injury are generally maintained at long-term follow up. Retrospective ratings using the DRS and FIL can help guide postacute rehabilitation planning within state or regional head injury programs.

Functional magnetic resonance imaging technology and traumatic brain injury rehabilitation: guidelines for methodological and conceptual pitfalls

OBJECTIVES

To illuminate the current methodological and conceptual pitfalls inherent in conducting functional magnetic resonance imaging (fMRI) research with individuals who have sustained traumatic brain injury (TBI) and to discuss appropriate remedies. The aim is describe fMRI research, its limitations, and how to best use this technology to examine TBI.

DISCUSSION

The topics discussed in this article include issues regarding signal detection, brain activation measurement, head movement, and sources of signal artifact. Issues surrounding data interpretation and the importance of analyzing the brain as a connected neural network is also discussed. Finally, problems with spatial normalization when examining individuals with TBI are reviewed.

CONCLUSIONS

To date, there is a scarcity of research applying fMRI technology to the study of TBI. However, because it is a noninvasive procedure with high availability in hospital settings across the country, the next decade of TBI research will likely include a proliferation of this form of investigation. At this time, much work is needed to better understand how to optimally use this technology to examine the effects of TBI on behavior. For fMRI to enhance TBI research it will be imperative to establish valid research protocols and reliable methods of data interpretation.

Prediction of functional outcomes after traumatic brain injury: a comparison of 2 measures of duration of unconsciousness

OBJECTIVE

To compare the usefulness of time until motor localization occurs versus time until commands are followed in predicting outcome after traumatic brain injury (TBI).

DESIGN

A retrospective analysis of data from a prospective cohort study of subjects with severe TBI.

SETTING

Seventeen Traumatic Brain Injury Model System programs.

PARTICIPANTS

A total of 496 subjects, recruited through the TBI Model System programs, with loss of consciousness greater than 1 day, with no late neurosurgical complications, and complete data for all measures.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Time until Glasgow Coma Scale (GCS) motor score of 5 (time to motor localization) and time until GCS motor score of 6 (time until commands were followed) were abstracted from medical records. Functional outcomes were assessed at inpatient rehabilitation admission and discharge, along with acute and rehabilitation lengths of stay and charges.

RESULTS

Time until commands were followed was a better predictor of all of the outcomes assessed than time until motor localization occurred. In multiple regression models, time until motor localization did not add significantly to the prediction provided by time until commands were followed. The predictive power of time to command following was superior even in the subgroup with poor language comprehension as measured by the Token Test.

CONCLUSION

Despite the theoretical appeal of time to motor localization (eg, in persons with language comprehension problems), time to command following appears to be a more powerful predictor of outcome after severe brain injury.

Long-term neuropsychological outcome after traumatic brain injury

OBJECTIVE

To describe neuropsychological outcome 5 years after injury in persons with traumatic brain injury (TBI) who received inpatient medical rehabilitation. To determine the magnitude and pattern neuropsychological recovery from 1 year to 5 years after injury.

DESIGN

Longitudinal cohort study with inclusion based on the availability of neuropsychological data at 1 year and 5 years after injury.

SETTING

National Institute on Disability and Rehabilitation Research Traumatic Brain Injury Model Systems of Care.

PARTICIPANTS

One hundred eighty-two persons with complicated mild to severe traumatic brain injury.

PRIMARY OUTCOME MEASURES

Digits Forward and Backward, Logical Memory I and II, Token Test, Controlled Oral Word Association Test, Symbol Digit Modalities Test, Trail Making Test, Rey Auditory Verbal Learning Test, Visual Form Discrimination, Block Design, Wisconsin Card Sorting Test, and Grooved Pegboard.

RESULTS

Significant variability in outcome was found 5 years after TBI, ranging from no measurable impairment to severe impairment on neuropsychological tests. Improvement from 1 year after injury to 5 years was also variable. Using the Reliable Change Index, 22.2% improved, 15.2% declined, and 62.6% were unchanged on test measures.

CONCLUSIONS

Neuropsychological recovery after TBI is not uniform across individuals and neuropsychological domains. For a subset of persons with moderate to severe TBI, neuropsychological recovery may continue several years after injury with substantial recovery. For other persons, measurable impairment remains 5 years after injury. Improvement was most apparent on measures of cognitive speed, visuoconstruction, and verbal memory.

Traumatic brain injury outcome: concepts for emergency care

Injury to the brain is the leading factor in mortality and morbidity from traumatic injury. The devastating personal, social, and financial consequences of traumatic brain injury (TBI) are compounded by the fact that most people with TBI are young and previously healthy. From the emergency physician's standpoint, patients with severe TBI are those with a presenting Glasgow Coma Scale score of less than 9. Over the past 30 years, mortality from severe traumatic brain injury for those patients who survive to the hospital has been reduced by half from nearly 50% to approximately 25%. Because most of the pathologic processes that determine outcome are fully active during the first hours after TBI, the decisions of emergency care providers may be crucial. This review addresses new concepts and information in the pathophysiology of TBI and secondary brain injury and demonstrates how emergency management may be linked to neurologic outcome.

A review of outcome after moderate and severe closed head injury with an introduction to life care planning

Forensic consultation regarding moderate and severe closed head injury (CHI) generally focuses on determination of severity of residual deficits and the implications of these deficits for future health care needs, personal independence, and employment. This information can be used to develop a life care plan that describes the patient's needs for continued medical care, rehabilitation, and daily assistance or supervision and estimates the long-term costs for these services. This article provides brief reviews of CHI classification, epidemiology, residual deficits, expected outcomes, and factors predictive of outcome. An introduction to the process of developing a life care plan is presented.

Prognostic indicators in medical rehabilitation of traumatic brain injury: a commentary and review

The National Information System (NIS) project is developing consensus opinion regarding a proposed structural framework for the prognostic data to be collected as part of this proposed multicenter research effort on severe traumatic brain injury (TBI). This article provide a brief history of the process, examines challenges facing rehabilitation research in this particular area, discusses reasons for identifying prognostic data within the research context of the NIS project, and describes methodologies for use of mathematical models in predicting outcome from TBI. The literature regarding prognostic parameters in severe TBI is briefly reviewed, utilizing three broad parameter categorizations: preinjury, injury, and postinjury. The implications of this research and directions for further study within the NIS project are discussed.