Long-term outcome following traumatic brain injury: A comparison of subjective reports by those injured and their relatives

Is dementia more likely following traumatic brain injury? A systematic review

BACKGROUND

The association between traumatic brain injury (TBI) and dementia is controversial, and of growing importance considering the ageing demography of TBI.

OBJECTIVE

To review the scope and quality of the existing literature investigating the relationship between TBI and dementia.

METHODS

We conducted a systematic review following PRISMA guidelines. Studies that compared TBI exposure and dementia risk were included. Studies were formally assessed for quality with a validated quality-assessment tool.

RESULTS

44 studies were included in the final analysis. 75% (n = 33) were cohort studies and data collection was predominantly retrospective (n = 30, 66.7%). 25 studies (56.8%) found a positive relationship between TBI and dementia. Clearly defined and valid measures of assessing TBI history were lacking (case-control studies-88.9%, cohort studies-52.9%). Most studies failed to justify a sample size (case-control studies-77.8%, cohort studies-91.2%), blind assessors to exposure (case-control-66.7%) or blind assessors to exposure status (cohort-3.00%). Studies that identified a relationship between TBI and dementia had a longer median follow-up time (120 months vs 48 months, p = 0.022) and were more likely to use validated TBI definitions (p = 0.01). Studies which clearly defined TBI exposure (p = 0.013) and accounted for TBI severity (p = 0.036) were also more likely to identify an association between TBI and dementia. There was no consensus method by which studies diagnosed dementia and neuropathological confirmation was only available in 15.5% of studies.

CONCLUSIONS

Our review suggests a relationship between TBI and dementia, but we are unable to predict the risk of dementia for an individual following TBI. Our conclusions are limited by heterogeneity in both exposure and outcome reporting and by poor study quality. Future studies should; (a) use validated methods to define TBI, accounting for TBI severity; (b) follow consensus agreement on criteria for dementia diagnosis; and (c) undertake follow-up that is both longitudinal, to determine if there is a progressive neurodegenerative change or static post-traumatic deficit, and of sufficient duration.

Personality changes after subarachnoid hemorrhage: A systematic review and meta-analysis

OBJECTIVE

Personality changes (PC) comprise a common and debilitating illness that accompanies many neurological disorders, including non-traumatic subarachnoid hemorrhage (SAH). The aim of this systematic review was to identify and critically appraise all published studies that have reported the frequency, severity, and time course of PC after SAH, the factors associated with the development of PC and the effects of PC on patients' lives after SAH.

METHODS

We searched the PubMed, EMBASE, PsycINFO, and Ovid Nursing databases for studies published in English that recruited at least 10 patients (>18 years old) after SAH who were also diagnosed with PC.

RESULTS

We found eight studies involving 1227 patients met the study entry criteria. The frequency of PC ranged from 32% to 59%, with a pooled frequency of 44%. The clinical course of PC after SAH was unclear. PC after SAH may be associated with the clinical features and treatment factors related to SAH and comorbid conditions. Neurological signs, disability and surgical treatment increased the risk of PC. PC reduced the study participants' chance of employment.

CONCLUSION

In summary, PC commonly occurs after SAH. Further research is needed to clarify the time course of PC and identify the risk factors, neurochemical factors, and brain circuits associated with the development of post-SAH PC. Randomized controlled treatment trials targeting SAH-related PC are warranted.

Cognitive Reserve, Early Cognitive Screening, and Relationship to Long-Term Outcome after Severe Traumatic Brain Injury

The objective was to investigate the relationship between early global cognitive functioning using the Barrow Neurological Institute Screen for Higher Cerebral Functions (BNIS) and cognitive flexibility (Trail Making Test (TMT), TMT B-A), with long-term outcome assessed by the Mayo-Portland Adaptability Index (MPAI-4) in severe traumatic brain injury (sTBI) controlling for the influence of cognitive reserve, age, and injury severity. Of 114 patients aged 18–65 with acute Glasgow Coma Scale 3–8, 41 patients were able to complete (BNIS) at 3 months after injury and MPAI-4 5–8 years after injury. Of these, 33 patients also completed TMT at 3 months. Global cognition and cognitive flexibility correlated significantly with long-term outcome measured with MPAI-4 total score (r_BNIS = 0.315; r_TMT = 0.355). Global cognition correlated significantly with the participation subscale (r = 0.388), while cognitive flexibility correlated with the adjustment (r = 0.364) and ability (r = 0.364) subscales. Adjusting for cognitive reserve and acute injury severity did not alter these relationships. The effect size for education on BNIS and TMT scores was large (d ≈ 0.85). Early screenings with BNIS and TMT are related to long-term outcome after sTBI and seem to measure complementary aspects of outcome. As early as 3 months after sTBI, educational level influences the scores on neuropsychological screening instruments.

Characterization of Ionic and Lipid Gradients within Corpus Callosum White Matter after Diffuse Traumatic Brain Injury in the Rat

There is increased recognition of the effects of diffuse traumatic brain injury (dTBI), which can initiate yet unknown biochemical cascades, resulting in delayed secondary brain degeneration and long-term neurological sequela. There is limited availability of therapies that minimize the effect of secondary brain damage on the quality of life of people who have suffered TBI, many of which were otherwise healthy adults. Understanding the cascade of biochemical events initiated in specific brain regions in the acute phase of dTBI and how this spreads into adjacent brain structures may provide the necessary insight into drive development of improved therapies. In this study, we have used direct biochemical imaging techniques (Fourier transform infrared spectroscopic imaging) and elemental mapping (X-ray fluorescence microscopy) to characterize biochemical and elemental alterations that occur in corpus callosum white matter in the acute phase of dTBI. The results provide direct visualization of differential biochemical and ionic changes that occur in the highly vulnerable medial corpus callosum white matter relative to the less vulnerable lateral regions of the corpus callosum. Specifically, the results suggest that altered ionic gradients manifest within mechanically damaged medial corpus callosum, potentially spreading to and inducing lipid alterations to white matter structures in lateral brain regions.

Good things better? Reappraisal and discrete emotions in acquired brain injury

There has been substantial interest in emotion after acquired brain injury (ABI), but less attention paid to emotion regulation (ER). Research has focused primarily on the ER strategy of reappraisal for regulating negative emotions, without distinguishing between classes of emotion, and there has been no attempt at exploring these differences in patients with ABI. The present study explored components of reappraisal, across classes of emotion, and their associated neuropsychological mechanisms. Thirty-five patients with ABI and twenty-two matched healthy control participants (HCs) completed two questionnaires, a battery of cognitive tasks, and an emotion regulation task (the Affective Story Recall Reappraisal task). Results suggest that those with ABI take longer, and generate fewer reappraisals than HCs across several discrete emotions. Notably, their ability to decrease emotional intensity did not differ significantly to HCs for negative emotions, but findings suggest that their reappraisals are less effective when up-regulating neutral emotions to positive. Working memory was the only significant predictor of the total number of reappraisals generated, and the time taken to produce a first reappraisal. Implications of these findings are discussed in the context of neuropsychological rehabilitation, including the role of the relatives in implementing and reinforcing micro-interventions.

The effect of subjective perception of cognition on emotional functioning in adults with long-term neurological and neuropsychiatric disorders

Purpose: To examine effects of subjective perception and objective status of cognition on emotional functioning in a sample of adults with long-term neurological and neuropsychiatric disorders.Method: N = 65. Subjective measures were derived from the self-ratings on the Problem Checklist (PCL) from the HI-FI; the objective status was represented by combined externally standardised scores on neuropsychological tests across three cognitive domains: verbal memory, executive functioning, and psychomotor speed.Results: No relationship was found between self-ratings of cognitive competence and performance on neuropsychological tests. Based on the results of the multiple regression analysis, approximately 40% of the variability in emotional functioning was explained by self-perceived cognitive and physical competence, while the addition of objective measures of cognition increased predictive capacity by only 1.3%. The awareness scores were calculated as the difference between objective performance scores and self-ratings of cognition. Overall, the sample demonstrated a tendency towards low awareness of cognitive deficits. Patients who overestimated cognitive deficits self-rated emotional functioning at a significantly lower level, while those with average or low awareness of deficits were equally emotionally content.Conclusions: Self-perception of competence, rather than objective level of functioning influence emotional well-being and quality of life in individuals with long-term disabilities in our study.IMPLICATIONS FOR REHABILITATIONCognitive deficits are common consequences of neurological dysfunction.This study shows that self-perception of cognitive competence, rather than objective level of cognitive functioning has critical influence on emotional well-being and perceived quality of life.An addition of psychotherapeutic intervention directed at alleviation of self-perception bias is likely to improve emotional well-being and enhance efficiency of rehabilitation efforts in patients with long-term disabilities due to neurological disorders.Based on our findings, patients with long-term disabilities could benefit from psychotherapy to improve their self-perception and quality of life.

Making sense of recovery after traumatic brain injury through a peer mentoring intervention: a qualitative exploration

OBJECTIVE

To explore the acceptability of peer mentoring for people with a traumatic brain injury (TBI) in New Zealand.

DESIGN

This is a qualitative descriptive study exploring the experiences reported by mentees and mentors taking part in a feasibility study of peer mentoring. Interviews with five mentees and six mentors were carried out. Data were analysed using conventional content analysis.

SETTING

The first mentoring session took place predischarge from the rehabilitation unit. The remaining five sessions took place in mentees' homes or community as preferred.

PARTICIPANTS

Twelve people with TBI took part: six mentees (with moderate to severe TBI; aged 18-46) paired with six mentors (moderate to severe TBI >12 months previously; aged 21-59). Pairing occurred before mentee discharge from postacute inpatient brain injury rehabilitation. Mentors had been discharged from rehabilitation following a TBI between 1 and 5 years previously.

INTERVENTION

The peer mentoring programme consisted of up to six face-to-face sessions between a mentee and a mentor over a 6-month period. The sessions focused on building rapport, exploring hopes for and supporting participation after discharge through further meetings and supported community activities.

RESULTS

Data were synthesised into one overarching theme: making sense of recovery. This occurred through the sharing of experiences and stories; was pivotal to the mentoring relationship; and appeared to benefit both mentees and mentors. Mentors were perceived as valued experts because of their personal experience of injury and recovery, and could provide support in ways that were different from that provided by clinicians or family members. Mentors required support to manage the uncertainties inherent in the role.

CONCLUSIONS

The insight mentors developed through their own lived experience established them as a trusted and credible source of hope and support for people re-engaging in the community post-TBI. These findings indicate the potential for mentoring to result in positive outcomes.

Interactive iBook-Based Patient Education in a NeuroTrauma Clinic

BACKGROUND

Traumatic brain injury (TBI) is a leading cause of death and disability in the United States. Educational interventions may alleviate the burden of TBI for patients and their families. Interactive modalities that involve engagement with the educational material may enhance patient knowledge acquisition when compared to static text-based educational material.

OBJECTIVE

To determine the effects of educational interventions in the outpatient setting on self-reported patient knowledge, with a focus on iPad-based (Apple, Cupertino, California) interactive modules.

METHODS

Patients and family members presenting to a NeuroTrauma clinic at a tertiary care academic medical center completed a presurvey assessing baseline knowledge of TBI or concussion, depending on the diagnosis. Subjects then received either an interactive iBook (Apple) on TBI or concussion, or an informative pamphlet with identical information in text format. Subjects then completed a postsurvey prior to seeing the neurosurgeon.

RESULTS

All subjects (n = 152) significantly improved on self-reported knowledge measures following administration of either an iBook (Apple) or pamphlet (P < .01, 95% confidence interval [CI]). Subjects receiving the iBook (n = 122) performed significantly better on the postsurvey (P < .01, 95% CI), despite equivalent presurvey scores, when compared to those receiving pamphlets (n = 30). Lastly, patients preferred the iBook to pamphlets (P < .01, 95% CI).

CONCLUSION

Educational interventions in the outpatient NeuroTrauma setting led to significant improvement in self-reported measures of patient and family knowledge. This improved understanding may increase compliance with the neurosurgeon's recommendations and may help reduce the potential anxiety and complications that arise following a TBI.

Perceived personality change after traumatic brain injury II: comparing participant and informant perspectives

OBJECTIVE

The objective of this paper was to correlate informant personality change (PC) judgements following moderate-severe traumatic brain injury with quantitative neurobehavioural measures and to contrast the neurobehavioural correlates of informant and participant judgements of PC.

PARTICIPANTS

Informant-participant pairs were recruited from a medico-legal clinic passing effort tests (N = 31) and a National Health Service clinic (N = 40).

MEASURES

Participants were assessed on Wechsler tests of general ability, tests of executive functioning (Zoo Map and Fluency) and emotional distress (Beck Depression Inventory-FastScreen, Hospital Anxiety and Depression Scale and State-Trait Anger Expression Inventory-II). Informants' expressed emotion towards participants was assessed with the family questionnaire. Both completed the DEX, the Frontal and Social Behavior Questionnaire and PC ratings.

RESULTS

The correlates of participant and informant ratings of participant PC partially overlapped. For example, participant self-reported PC was associated with self-reported dysexecutive symptoms and emotional distress. In contrast, informant report of participant PC was associated with lower perceived emotional recognition and empathy, informant report of dysexecutive symptoms and high informant expressed emotion.

CONCLUSIONS

It is argued that whilst researchers aim to exhaustively quantify specific neurobehavioural changes and their clusters, partially overlapping subsets of these changes evoke the PC judgements of participants and informants. The clinical implications of this are briefly considered.

Mild traumatic brain injury in New Zealand: factors influencing post-concussion symptom recovery time in a specialised concussion service

ABSTRACT INTRODUCTION By 2020, traumatic brain injuries (TBIs) are predicted to become the third largest cause of disease burden globally; 90% of these being mild traumatic brain injury (mTBI). Some patients will develop post-concussion syndrome. AIM To determine whether the time between sustaining a mTBI and the initial assessment by a specialised concussion service, along with the post-concussion symptoms reported at the assessment, affected recovery time. METHODS A retrospective medical record review of clients who had completed the Rivermead Post-Concussion Questionnaire (RPQ) at their initial assessment and were discharged from a large metropolitan concussion service in New Zealand was undertaken over a 6-month period in 2014 (n = 107). Using correlations, General Linear Mixed-effects Models (GLMM) and linear regressions, we explored associations between factors including ethnicity, gender and accident type, along with individual RPQ symptom scores and cluster scores, with time from injury to initial assessment by the specialised concussion service and initial assessment to discharge. RESULTS Time from injury to initial assessment by a specialist concussion service was correlated with proportionally more psychological symptoms present at initial assessments (r = 0.222, P = 0.024); in particular, feeling depressed or tearful (r = 0.292, P = 0.003). Time to discharge was correlated with individual RPQ symptom proportions present at initial assessment for headaches (r = –0.238, P = 0.015), sensitivity to noise (r = 0.220, P = 0.026), feeling depressed or tearful (r = 0.193, P = 0.051) and feeling frustrated or impatient (r = 0.252, P = 0.003), along with the psychological cluster proportion (r = 0.235, P = 0.017) and the total RPQ score (r = 0.425, P < 0.001). CONCLUSION Prompt diagnosis and treatment of mTBI may minimise the severity of post-concussion symptoms, especially symptoms associated with mental health and wellbeing.

Self-awareness four years after severe traumatic brain injury: discordance between the patient’s and relative’s complaints. Results from the PariS-TBI study

Objective:

To evaluate the patient’s awareness of his or her difficulties in the chronic phase of severe traumatic brain injury (TBI) and to determine the factors related to poor awareness.

Design/Setting/Subjects:

This study was part of a larger prospective inception cohort study of patients with severe TBI in the Parisian region (PariS-TBI study).

Intervention/Main measures:

Evaluation was carried out at four years and included the Brain Injury Complaint Questionnaire (BICoQ) completed by the patient and his or her relative as well as the evaluation of impairments, disability and quality of life.

Results:

A total of 90 patient-relative pairs were included. Lack of awareness was measured using the unawareness index that corresponded to the number of discordant results between the patient and relative in the direction of under evaluation of difficulties by the patient. The only significant relationship found with lack of awareness was the subjective burden perceived by the relative (Zarit Burden Inventory) ( r = 0.5; P < 0.00001). There was no significant relationship between lack of awareness and injury severity, pre-injury socio-demographic data, cognitive impairments, mood disorders, functional independence (Barthel index), global disability (Glasgow Outcome Scale), return to work at four years or quality of life (Quality Of Life after Brain Injury scale (QOLIBRI)).

Conclusion:

Lack of awareness four years post severe TBI was not related to the severity of the initial trauma, sociodemographic data, the severity of impairments, limitations of activity and participation, or the patient’s quality of life. However, poor awareness did significantly influence the weight of the burden perceived by the relative.

Subjective complaints after acquired brain injury: presentation of the Brain Injury Complaint Questionnaire (BICoQ)

The objective of the present study was to present a new complaint questionnaire designed to assess a wide range of difficulties commonly reported by patients with acquired brain injury. Patients (n =  619) had been referred to a community re-entry service at a chronic stage after brain injury, mainly traumatic brain injury (TBI). The Brain Injury Complaint Questionnaire (BICoQ) includes 25 questions in the following domains: cognition, behavior, fatigue and sleep, mood, and somatic problems. A self and a proxy questionnaire were given. An additional question was given to the relative, about the patient's awareness of his difficulties. The questionnaires had a good internal coherence, as measured with Cronbach's alpha. The most frequent complaints were, in decreasing order, mental slowness, memory troubles, fatigue, concentration difficulties, anxiety, and dual tasking problems. Principal component analysis with varimax rotation yielded six underlying factors explaining 50.5% of total variance: somatic concerns, cognition, and lack of drive, lack of control, psycholinguistic disorders, mood, and mental fatigue/slowness. About 52% of patients reported fewer complaints than their proxy, suggesting lack of awareness. The total complaint scores were not significantly correlated with any injury severity measure, but were significantly correlated with disability and poorer quality of life (Note: only factor 2 [cognition/lack of drive] was significantly related to disability.) The BICoQ is a simple scale that can be used in addition to traditional clinical and cognitive assessment measures, and to assess awareness of everyday life problems.

A narrative literature review of depression following traumatic brain injury: prevalence, impact, and management challenges

Depression is one of the most common conditions to emerge after traumatic brain injury (TBI), and despite its potentially serious consequences it remains undertreated. Treatment for post-traumatic depression (PTD) is complicated due to the multifactorial etiology of PTD, ranging from biological pathways to psychosocial adjustment. Identifying the unique, personalized factors contributing to the development of PTD could improve long-term treatment and management for individuals with TBI. The purpose of this narrative literature review was to summarize the prevalence and impact of PTD among those with moderate to severe TBI and to discuss current challenges in its management. Overall, PTD has an estimated point prevalence of 30%, with 50% of individuals with moderate to severe TBI experiencing an episode of PTD in the first year after injury alone. PTD has significant implications for health, leading to more hospitalizations and greater caregiver burden, for participation, reducing rates of return to work and affecting social relationships, and for quality of life. PTD may develop directly or indirectly as a result of biological changes after injury, most notably post-injury inflammation, or through psychological and psychosocial factors, including pre injury personal characteristics and post-injury adjustment to disability. Current evidence for effective treatments is limited, although the strongest evidence supports antidepressants and cognitive behavioral interventions. More personalized approaches to treatment and further research into unique therapy combinations may improve the management of PTD and improve the health, functioning, and quality of life for individuals with TBI.

Association Between Traumatic Brain Injury-Related Brain Lesions and Long-term Caregiver Burden

OBJECTIVE

To investigate the association between traumatic brain injury (TBI)-related brain lesions and long-term caregiver burden in relation to dysexecutive syndrome.

SETTING

National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland.

PARTICIPANTS

A total of 256 participants: 105 combat veterans with TBI, 23 healthy control combat veterans (HCv), and 128 caregivers.

OUTCOME MEASURE

Caregiver burden assessed by the Zarit Burden Interview at 40 years postinjury.

DESIGN

Participants with penetrating TBI were compared with HCv on perceived caregiver burden and neuropsychological assessment measures. Data of computed tomographic scans (overlay lesion maps of participants with a penetrating TBI whose caregivers have a significantly high burden) and behavioral statistical analyses were combined to identify brain lesions associated with caregiver burden.

RESULTS

Burden was greater in caregivers of veterans with TBI than in caregivers of HCv. Caregivers of participants with lesions affecting cognitive and behavioral indicators of dysexecutive syndrome (ie, left dorsolateral prefrontal cortex and dorsal anterior cingulate cortex) showed greater long-term burden than caregivers of participants with lesions elsewhere in the brain.

CONCLUSION AND IMPLICATION

The TBI-related brain lesions have a lasting effect on long-term caregiver burden due to cognitive and behavioral factors associated with dysexecutive syndrome.

Traumatic Brain Injury Due to Screwdriver Assaults: Literature Review and Case Report

Penetrating head injuries due to the use of screwdrivers as wounding agents in acts of interpersonal violence seldom occur. The aim of this article is to update and summarize the relevant literature on penetrating craniocerebral screwdriver stab wounds and to report a new case of screwdriver assault. A number of studies were reviewed to investigate the incidence, distribution, common findings, mechanism of injury, differential diagnostic criteria, complications, treatment, and prognosis of craniocerebral screwdriver stab injuries. It was observed that the degree of traumatic severity depends on the cross-sectional area of the screwdriver and the anatomical region of injury. Craniocerebral screwdriver injuries are mainly cases of interpersonal violence and the mortality rate is approximately 47.6%. In 23.8% of the incidents, the trauma is overlooked on admission because of the small entry wound and, thus, the severity of the injury is not initially appreciated.

Hypo-excitation across all cortical laminae defines intermediate stages of cortical neuronal dysfunction in diffuse traumatic brain injury

Traumatic brain injury (TBI) is a major cause of morbidity and mortality world-wide and can result in persistent cognitive, sensory and behavioral dysfunction. Understanding the time course of TBI-induced pathology is essential to effective treatment outcomes. We induced TBI in rats using an impact acceleration method and tested for sensorimotor skill and sensory sensitivity behaviors for two weeks to find persistently poor outcomes post-injury. At two weeks post-injury we made high resolution extracellular recordings from barrel cortex neurons, to simple and complex whisker deflections. We found that the supragranular suppression of neural firing (compared to normal) previously seen in the immediate post-TBI aftermath had spread to include suppression of input and infragranular layers at two weeks post-injury; thus, there was suppression of whisker-driven firing rates in all cortical layers to both stimulus types. Further, there were abnormalities in temporal response patterns such that in layers 3-5 there was a temporal broadening of response patterns in response to both whisker deflection stimulus types and in L2 a narrowing of temporal patterns in response to the complex stimulus. Thus, at two weeks post-TBI, supragranular hypo-excitation has evolved to include deep cortical layers likely as a function of progressive atrophy and neurodegeneration. These results are consistent with the hypothesis that TBI alters the delicate excitatory/inhibitory balance in cortex and likely contributes to temporal broadening of responses and restricts the ability to code for complex sensory stimuli.

The impact of physical therapy in patients with severe traumatic brain injury during acute and post-acute rehabilitation according to coma duration

[Purpose] The aim of study was to evaluate the impact of physical therapy on the recovery of motor and mental status in patients who sustained a severe traumatic brain injury, according to coma duration in acute and post-acute rehabilitation. [Subjects and Methods] The study population comprised patients with levels of consciousness ranging from 3 to 8 according to Glasgow Coma Scale score. The patients were divided into 2 groups based on coma duration as follows: group 1, those who were in a coma up to 1 week, and group 2, those who were in a coma for more than 2 weeks. The recovery of the patients' motor function was evaluated according to the Motor Assessment Scale and the recovery of mental status according to the Mini-Mental State Examination. [Results] The evaluation of motor and mental status recovery revealed that the patients who were in a coma up to 1 week recovered significantly better after physical therapy during the acute rehabilitation than those who were in a coma for longer than 2 weeks. [Conclusion] The recovery of motor and mental status of the patients in acute rehabilitation was significantly better for those in a coma for a shorter period.

Traumatic Brain Injury and Neuronal Functionality Changes in Sensory Cortex

Traumatic brain injury (TBI), caused by direct blows to the head or inertial forces during relative head-brain movement, can result in long-lasting cognitive and motor deficits which can be particularly consequential when they occur in young people with a long life ahead. Much is known of the molecular and anatomical changes produced in TBI but much less is known of the consequences of these changes to neuronal functionality, especially in the cortex. Given that much of our interior and exterior lives are dependent on responsiveness to information from and about the world around us, we have hypothesized that a significant contributor to the cognitive and motor deficits seen after TBI could be changes in sensory processing. To explore this hypothesis, and to develop a model test system of the changes in neuronal functionality caused by TBI, we have examined neuronal encoding of simple and complex sensory input in the rat’s exploratory and discriminative tactile system, the large face macrovibrissae, which feeds to the so-called “barrel cortex” of somatosensory cortex. In this review we describe the short-term and long-term changes in the barrel cortex encoding of whisker motion modeling naturalistic whisker movement undertaken by rats engaged in a variety of tasks. We demonstrate that the most common form of TBI results in persistent neuronal hyperexcitation specifically in the upper cortical layers, likely due to changes in inhibition. We describe the types of cortical inhibitory neurons and their roles and how selective effects on some of these could produce the particular forms of neuronal encoding changes described in TBI, and then generalize to compare the effects on inhibition seen in other forms of brain injury. From these findings we make specific predictions as to how non-invasive extra-cranial electrophysiology can be used to provide the high-precision information needed to monitor and understand the temporal evolution of changes in neuronal functionality in humans suffering TBI. Such detailed understanding of the specific changes in an individual patient’s cortex can allow for treatment to be tailored to the neuronal changes in that particular patient’s brain in TBI, a precision that is currently unavailable with any technique.

Unfolded Maps for Quantitative Analysis of Cortical Lesion Location and Extent after Traumatic Brain Injury

We aimed to generate two-dimensional (2D) unfolded cortical maps from magnetic resonance (MR) images to delineate the location of traumatic brain injury (TBI)-induced cortical damage in functionally diverse cytoarchitectonic areas of the cerebral cortex, and to predict the severity of functional impairment after TBI based on the lesion location and extent. Lateral fluid-percussion injury was induced in adult rats and T2 maps were acquired with magnetic resonance imaging (MRI) at 3 days post-TBI. Somatomotor deficits were assessed based on the composite neuroscore and beam balance test, and spatial learning was assessed in the Morris water maze. Animals were perfused for histology at 13 days post-injury. A 2D template was generated by unfolding the cerebral cortex from 26 sections of the rat brain atlas, covering the lesion extent. Next, 2D unfolded maps were generated from T2 maps and thionin-stained histological sections from the same animals. Unfolding of the T2 maps revealed the lesion core in the auditory, somatosensory, and visual cortices. The unfolded histological lesion at 13 days post-injury was 12% greater than the MRI lesion at 3 days post-TBI, as the lesion area increased laterally and caudally; the larger the MRI lesion area, the larger the histological lesion area. Further, the larger the MRI lesion area in the barrel field of the primary somatosensory cortex (S1BF), upper lip of the primary somatosensory cortex (S1ULp), secondary somatosensory division (S2), and ectorhinal (Ect) and perirhinal (PRh) cortices, the more impaired the performance in the beam balance and Morris water maze tests. Subsequent receiver operating characteristic analysis indicated that severity of the MRI lesion in S1ULp and S2 was a sensitive and specific predictor of poor performance in the beam balance test. Moreover, MRI lesions in the S1ULp, S2, S1BF, and Ect and PRh cortices predicted poor performance in the Morris water maze test. Our findings indicate that 2D-unfolded cortical maps generated from MR images delineate the distribution of cortical lesions in functionally different cytoarchitectonic regions, which can be used to predict the TBI-induced functional impairment.

Illness Representations of Injury: A Comparison of Patients and Their Caregivers

PURPOSE

This study examined the differences between illness representations of injured patients and those of their caregivers.

DESIGN

A comparative descriptive survey was used.

METHODS

The study setting was the surgical wards of a teaching hospital in Taiwan. Data were collected at 3 to 6 months after hospital discharge. Participants were 127 pairs of injured patients and their caregivers. The participants completed sociodemographic data and completed the Chinese Illness Perception Questionnaire Revised-Trauma, which is composed of eight subscales. Clinical data of the injured patients was obtained from medical records.

RESULTS

Injured patients and their caregivers were pessimistic about the injury. Patients perceived significantly more physical symptoms than caregivers did. Caregivers for patients who were severely injured or admitted to an intensive care unit (ICU) had more negative perceptions than did those who were providing care for moderately injured patients or those not admitted to an ICU. Caregivers who did not share their caring responsibilities had more negative perceptions than did those who shared their caring responsibilities with others.

CONCLUSIONS

This study found that patients and caregivers had negative illness representations several months after injury. Caregivers who provided care for severely injured patients or who did not share caring responsibilities perceived different extents of illness perceptions about the injury. The interventions should highlight the need to assist patients and caregivers after injury.

CLINICAL RELEVANCE

Exploring the discrepancies in illness perceptions between injured patients and their caregivers can help clinicians to provide individualized care, and to design interventions that meet patients' and caregivers' needs.

Reporting of neuropsychological dysfunction remains discrepant between individuals with traumatic brain injury and their close others up to five years post-injury

PURPOSE

The degree to which individuals with traumatic brain injury (TBI) and their close others share a common understanding and experience of post-injury neuropsychological changes is currently unclear. The aim of this preliminary study was to longitudinally examine levels of agreement between self and close other reports of neuropsychological dysfunction following TBI and explore factors associated with these agreement levels.

METHOD

Sixty-three people with TBI and their nominated close others independently completed the Structured Outcome Questionnaire at 1- and 5-years post-injury, reporting whether the person with TBI was experiencing any negative cognitive, behavioural or emotional changes compared to pre-injury.

RESULTS

Agreement levels between pair members ranged from chance to approximately 75% across neuropsychological domains and did not significantly change over 1- and 5-year time points. In the case of pair disagreement, close others were generally more likely to report difficulties. Pair disagreement was significantly associated with close other anxiety.

CONCLUSIONS

Agreement between self and close others remains limited up to 5-years post-injury which questions the practice of using these reports interchangeably in research and clinical practice. Preliminary findings suggest some association between pair disagreement and close other psychological function; however, further research is warranted. Implications for Rehabilitation Reporting of neuropsychological dysfunction between individuals with TBI and their close others is not sufficiently reliable to warrant interchangeable use within research or clinical practice. Including both individuals with TBI and their close others in clinical assessments will facilitate a more holistic understanding of the client's difficulties and their relationships with those close to them. Preliminary findings indicate that disagreement between individuals with TBI and their close others may be associated with close other anxiety. Clinicians should be aware of the potential for disagreement to impact on the psychological health of close others.

Preservation of the blood brain barrier and cortical neuronal tissue by liraglutide, a long acting glucagon-like-1 analogue, after experimental traumatic brain injury

Cerebral edema is a common complication following moderate and severe traumatic brain injury (TBI), and a significant risk factor for development of neuronal death and deterioration of neurological outcome. To this date, medical approaches that effectively alleviate cerebral edema and neuronal death after TBI are not available. Glucagon-like peptide-1 (GLP-1) has anti-inflammatory properties on cerebral endothelium and exerts neuroprotective effects. Here, we investigated the effects of GLP-1 on secondary injury after moderate and severe TBI. Male Sprague Dawley rats were subjected either to TBI by Controlled Cortical Impact (CCI) or sham surgery. After surgery, vehicle or a GLP-1 analogue, Liraglutide, were administered subcutaneously twice daily for two days. Treatment with Liraglutide (200 μg/kg) significantly reduced cerebral edema in pericontusional regions and improved sensorimotor function 48 hours after CCI. The integrity of the blood-brain barrier was markedly preserved in Liraglutide treated animals, as determined by cerebral extravasation of Evans blue conjugated albumin. Furthermore, Liraglutide reduced cortical tissue loss, but did not affect tissue loss and delayed neuronal death in the thalamus on day 7 post injury. Together, our data suggest that the GLP-1 pathway might be a promising target in the therapy of cerebral edema and cortical neuronal injury after moderate and severe TBI.

Longitudinal follow-up of patients with traumatic brain injury: outcome at two, five, and ten years post-injury

The deleterious consequences of traumatic brain injury (TBI) impair capacity to return to many avenues of pre-morbid life. However, there has been limited longitudinal research examining outcome beyond five years post-injury. The aim of this study was to examine aspects of function, previously shown to be affected following TBI, over a span of 10 years. One hundred and forty one patients with TBI were assessed at two, five, and 10 years post-injury using the Structured Outcome Questionnaire. Fatigue and balance problems were the most common neurological symptoms, with reported rates decreasing only slightly during the 10-year period. Mobility outcomes were good in more than 75% of patients, with few participants requiring aids for mobility. Changes in cognitive, communication, behavioral, and emotional functions were reported by approximately 60% of the sample at all time points. Levels of independence in activities of daily living were high during the 10-year period, and as many as 70% of subjects returned to driving. Nevertheless, approximately 40% of patients required more support than before their injury. Only half the sample returned to previous leisure activities and fewer than half were employed at each assessment time post-injury. Although marital status remained stable over time, approximately 30% of participants reported difficulties in personal relationships. Older age at injury did not substantially alter the pattern of changes over time, except in employment. Overall, problems that were evident at two years post-injury persisted until 10 years post-injury. The importance of these findings is discussed with reference to rehabilitation programs.

Environmental enrichment and the sensory brain: the role of enrichment in remediating brain injury

The brain's life-long capacity for experience-dependent plasticity allows adaptation to new environments or to changes in the environment, and to changes in internal brain states such as occurs in brain damage. Since the initial discovery by Hebb (1947) that environmental enrichment (EE) was able to confer improvements in cognitive behavior, EE has been investigated as a powerful form of experience-dependent plasticity. Animal studies have shown that exposure to EE results in a number of molecular and morphological alterations, which are thought to underpin changes in neuronal function and ultimately, behavior. These consequences of EE make it ideally suited for investigation into its use as a potential therapy after neurological disorders, such as traumatic brain injury (TBI). In this review, we aim to first briefly discuss the effects of EE on behavior and neuronal function, followed by a review of the underlying molecular and structural changes that account for EE-dependent plasticity in the normal (uninjured) adult brain. We then extend this review to specifically address the role of EE in the treatment of experimental TBI, where we will discuss the demonstrated sensorimotor and cognitive benefits associated with exposure to EE, and their possible mechanisms. Finally, we will explore the use of EE-based rehabilitation in the treatment of human TBI patients, highlighting the remaining questions regarding the effects of EE.

Diffuse traumatic brain injury and the sensory brain

In this review we discuss the consequences to the brain's cortex, specifically to the sensory cortex, of traumatic brain injury. The thesis underlying this approach is that long-term deficits in cognition seen after brain damage in humans are likely underpinned by an impaired cortical processing of the sensory information needed to drive cognition or to be used by cognitive processes to produce a response. We take it here that the impairment to sensory processing does not arise from damage to peripheral sensory systems, but from disordered brain processing of sensory input.

The impact of self-awareness and depression on subjective reports of memory, quality-of-life and satisfaction with life following TBI

OBJECTIVE

To determine the relationship between self-awareness and depressive symptomatology with self-reports of memory, Quality-of-Life (QoL) and satisfaction with life in individuals with traumatic brain injury (TBI).

METHODS

Cross-sectional survey of 30 community dwelling adults, who sustained a TBI at least 1 year prior to study enrolment. Participants completed questionnaires to assess the constructs of depression, self-awareness, QoL, satisfaction with life and memory.

RESULTS

Symptoms of depression were significantly associated with self-reports of poor memory abilities, lower QoL and lower satisfaction with life. Additionally, higher levels of self-awareness were associated with lower ratings of QoL and reduced memory abilities and better strategy use regarding memory. However, when examining the contribution of each construct individually, depressive symptomatology, and not self-awareness, was significantly associated with subjective self-reports of memory, QoL and satisfaction with life.

CONCLUSIONS

This pattern of relationships illustrates that, when a person has a low level of depressive symptoms, his/her reports of QoL, memory and satisfaction with life will be more positive; however, he/she will demonstrate more difficulty with self-awareness. Thus, psychological aspects of recovery must, therefore, be taken into account when using self-reported measures in the evaluation of persons who have sustained TBI.

Self versus family ratings of the frontal systems behaviour scale and measured executive functions: adult outcomes following childhood traumatic brain injury

Traumatic brain injury (TBI) frequently occurs during childhood and adolescence with long-term neuropsychological and behavioral effects. Greater personal awareness of injury is associated with better outcomes. However, personal awareness is often assessed using ratings obtained from family members or significant others. Surprisingly, the accuracy of family-ratings compared with self-ratings has not been well studied in the TBI population. Thus, the purpose of this study was to examine self versus family-ratings of frontal dysfunction and secondly, the association between self/family reported frontal dysfunction and measured executive function outcomes. A total of 60 participants, approximately 10 years post-TBI, comprised 3 groups including; moderate/severe TBI (N=26; mean age 22.9, SD=3.0), mild TBI (N=20; mean age, 21.7, SD=2.7), and control (N=14: mean age, 21.6, SD=3.7). Neuropsychological testing was used to obtain domain scores for executive function and working memory/attention for each participant, and nominated family members and participants with TBI were asked to complete the Frontal Systems Behaviour Scale (FrSBe), consisting of three sub-scales; apathy, disinhibition, and executive dysfunction. Using the FrSBe there was no significant difference between the groups in executive function score, but the moderate/severe and mild groups had significantly lower working memory/attention scores compared with the control group (p<0.05). Repeated measures analysis of variance showed higher self-ratings on all sub-scales compared with family in each group (p<0.05). Scores on executive function and working memory/attention domains correlated with self, but not family reported executive dysfunction. Self-rated executive dysfunction explained 36% of the variance in executive function (p<0.001). While agreement between self-rated and family-rated total FrSBe scores was significant in all groups (p<0.001), our results showed that self-ratings were of higher predictive utility for executive functioning compared with family ratings. Further, at 10 years post-TBI, patients show greater awareness of deficits compared with family who rate consistently closer to the normal functioning range.

Modeling the prospective relationships of impairment, injury severity, and participation to quality of life following traumatic brain injury

Identifying reliable predictors of positive adjustment following traumatic brain injury (TBI) remains an important area of inquiry. Unfortunately, much of available research examines direct relationships between predictor variables and outcomes without attending to the contextual relationships that can exist between predictor variables. Relying on theoretical models of well-being, we examined a theoretical model of adjustment in which the capacity to engage in intentional activities would be prospectively associated with greater participation, which in turn would predict subsequent life satisfaction and perceived health assessed at a later time. Structural equation modeling of data collected from 312 individuals (226 men, 86 women) with TBI revealed that two elements of participation--mobility and occupational activities--mediated the prospective influence of functional independence and injury severity to optimal adjustment 60 months following medical discharge for TBI. The model accounted for 21% of the variance in life satisfaction and 23% of the variance in self-rated health. Results indicate that the effects of functional independence and injury severity to optimal adjustment over time may be best understood in the context of participation in meaningful, productive activities. Implications for theoretical models of well-being and for clinical interventions that promote adjustment after TBI are discussed.

Health-related quality of life in traumatic brain injury: is a proxy report necessary?

Despite its importance to care, clinicians and researchers often discount patient-reported outcomes in favor of proxy reports, in persons with traumatic brain injury (TBI). The rationale relates to concerns about lack of awareness of patients regarding their functioning. However, although lack of awareness occurs in some patients with severe TBI, or in TBI involving certain lesion locations, or very soon after injury, this conclusion has been overgeneralized. The objective of this study is to determine the validity of patient-reported health-related quality of life by evaluating its relationship to injury severity and more objective indices of outcome, in a representative series of adults with TBI. A consecutive sample of 374 persons with TBI at least 14 years old, and having a post-resuscitation Glasgow Coma Scale score ≤12, an acute seizure, or a CT scan showing TBI- related findings. Seventy-six percent (374/491) of the eligible survivors were assessed at 6 months post-injury on the Life Satisfaction Survey. The greatest decrease in satisfaction was in the ability to think and remember, work, receive adequate income, and participate in leisure and recreational activities. Dissatisfaction significantly related to the functional limitation in that area as judged by the patients themselves (p<0.001) or by someone who knew them well (p≤0.001). The most severely injured group reported the most dissatisfaction for 13 out of 17 areas assessed. Patients with TBI, in general, do not need a proxy to report on their behalf regarding their functional limitations or health-related quality of life.

Sensory cortex underpinnings of traumatic brain injury deficits

Traumatic brain injury (TBI) can result in persistent sensorimotor and cognitive deficits including long-term altered sensory processing. The few animal models of sensory cortical processing effects of TBI have been limited to examination of effects immediately after TBI and only in some layers of cortex. We have now used the rat whisker tactile system and the cortex processing whisker-derived input to provide a highly detailed description of TBI-induced long-term changes in neuronal responses across the entire columnar network in primary sensory cortex. Brain injury (n = 19) was induced using an impact acceleration method and sham controls received surgery only (n = 15). Animals were tested in a range of sensorimotor behaviour tasks prior to and up to 6 weeks post-injury when there were still significant sensorimotor behaviour deficits. At 8–10 weeks post-trauma, in terminal experiments, extracellular recordings were obtained from barrel cortex neurons in response to whisker motion, including motion that mimicked whisker motion observed in awake animals undertaking different tasks. In cortex, there were lamina-specific neuronal response alterations that appeared to reflect local circuit changes. Hyper-excitation was found only in supragranular layers involved in intra-areal processing and long-range integration, and only for stimulation with complex, naturalistic whisker motion patterns and not for stimulation with simple trapezoidal whisker motion. Thus TBI induces long-term directional changes in integrative sensory cortical layers that depend on the complexity of the incoming sensory information. The nature of these changes allow predictions as to what types of sensory processes may be affected in TBI and contribute to post-trauma sensorimotor deficits.

The effect of injury severity on behavior: a phenotypic study of cognitive and emotional deficits after mild, moderate, and severe controlled cortical impact injury in mice

Traumatic brain injury (TBI) can cause a broad array of behavioral problems including cognitive and emotional deficits. Human studies comparing neurobehavioral outcomes after TBI suggest that cognitive impairments increase with injury severity, but emotional problems such as anxiety and depression do not. To determine whether cognitive and emotional impairments increase as a function of injury severity we exposed mice to sham, mild, moderate, or severe controlled cortical impact (CCI) and evaluated performance on a variety of neurobehavioral tests in the same animals before assessing lesion volume as a histological measure of injury severity. Increasing cortical impact depth successfully produced lesions of increasing severity in our model. We found that cognitive impairments in the Morris water maze increased with injury severity, as did the degree of contralateral torso flexion, a measure of unilateral striatal damage. TBI also caused deficits in emotional behavior as quantified in the forced swim test, elevated-plus maze, and prepulse inhibition of acoustic startle, but these deficits were not dependent on injury severity. Stepwise regression analyses revealed that Morris water maze performance and torso flexion predicted the majority of the variability in lesion volume. In summary, we find that cognitive deficits increase in relation to injury severity, but emotional deficits do not. Our data suggest that the threshold for emotional changes after experimental TBI is low, with no variation in behavioral deficits seen between mild and severe brain injury.

Depression following traumatic brain injury: epidemiology, risk factors and management

It is important for clinicians to recognize major depression following traumatic brain injury (TBI) because of its association with poor global and psychosocial outcome, postconcussive symptoms and cognitive deficits. The purpose of this review is to provide an up-to-date selective review of the current understanding of epidemiology, risk factors and management of major depression following TBI. Many studies of prevalence of depression following TBI have not used accepted structured criteria for the diagnoses, but those that did found wide ranges of rates, from 17% to 61%. The risk factors for development of depression following TBI are poorly understood, but past psychiatric history, frontal lesions and atrophy, and family dysfunction have been shown in more than one study to play important roles. There are few controlled trials of the treatment of major depression in patients with TBI using accepted diagnostic criteria for major depression, as well as defined criteria for response and remission. As such, it is important for clinicians to use best practice guidelines for the treatment of major depression in the absence of TBI.

Long-term cognitive and emotional consequences of mild traumatic brain injury

BACKGROUND

The objective of this study was to investigate long-term cognitive and emotional sequelae of mild traumatic brain injury (mTBI), as previous research has remained inconclusive with respect to their prevalence and extent.

METHOD

Thirty-three individuals who had sustained mTBI on average 6 years prior to the study and 33 healthy control subjects were matched according to age, gender and education. Structural brain damage at time of testing was excluded by magnetic resonance imaging (MRI). A comprehensive neuropsychological test battery was conducted to assess learning, recall, working memory, attention and executive function. Psychiatric symptoms were assessed by the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) and the Beck Depression Inventory (BDI). Possible negative response bias was ruled out by implementing the Word Memory Test (WMT).

RESULTS

The mTBI individuals had significant impairments in all cognitive domains compared to the healthy control subjects. Effect sizes of cognitive deficits were medium to large, and could not be accounted for by self-perceived deficits, depression, compensation claims or negative response bias. BDI scores were significantly higher in the patient group, and three patients fulfilled DSM-IV criteria for a mild episode of major depression.

CONCLUSIONS

Primarily, well-recovered individuals who had sustained a minor trauma more than half a decade ago continue to have long-term cognitive and emotional sequelae relevant for everyday social and professional life. mTBI may lead to a lasting disruption of neurofunctional circuits not detectable by standard structural MRI and needs to be taken seriously in clinical and forensic evaluations.