Coping styles, cortisol reactivity, and performance in a vigilance task of patients with persistent postconcussive symptoms after a mild head injury

An integrated perspective linking physiological and psychological consequences of mild traumatic brain injury

Despite the often seemingly innocuous nature of a mild traumatic brain injury (mTBI), its consequences can be devastating, comprising debilitating symptoms that interfere with daily functioning. Currently, it is still difficult to pinpoint the exact cause of adverse outcome after mTBI. In fact, extensive research suggests that the underlying etiology is multifactorial. In the acute and early sub-acute stages, the pathophysiology of mTBI is likely to be dominated by complex physiological alterations including cellular injury, inflammation, and the acute stress response, which could lead to neural network dysfunction. In this stage, patients often report symptoms such as fatigue, headache, unstable mood and poor concentration. When time passes, psychological processes, such as coping styles, personality and emotion regulation, become increasingly influential. Disadvantageous, maladaptive, psychological mechanisms likely result in chronic stress which facilitates the development of long-lasting symptoms, possibly via persistent neural network dysfunction. So far, a systemic understanding of the coupling between these physiological and psychological factors that in concert define outcome after mTBI is lacking. The purpose of this narrative review article is to address how psychophysiological interactions may lead to poor outcome after mTBI. In addition, a framework is presented that may serve as a template for future studies on this subject.

Resilience priming: Translational models for understanding resiliency and adaptation to early life adversity

Despite the increasing attention to early life adversity and its long-term consequences on health, behavior, and the etiology of neurodevelopmental disorders, our understanding of the adaptations and interventions that promote resiliency and rescue against such insults are underexplored. Specifically, investigations of the perinatal period often focus on negative events/outcomes. In contrast, positive experiences (i.e. enrichment/parental care//healthy nutrition) favorably influence development of the nervous and endocrine systems. Moreover, some stressors result in adaptations and demonstrations of later-life resiliency. This review explores the underlying mechanisms of neuroplasticity that follow some of these early life experiences and translates them into ideas for interventions in pediatric settings. The emerging role of the gut microbiome in mediating stress susceptibility is also discussed. Since many negative outcomes of early experiences are known, it is time to identify mechanisms and mediators that promote resiliency against them. These range from enrichment, quality parental care, dietary interventions and those that target the gut microbiota.

Interventions to enhance coping after traumatic brain injury: A systematic review

Background/Aims:

The aim of this study was to identify effective psychosocial interventions to enhance coping in people who have experienced a traumatic brain injury, in order to inform clinical practice and articulate future research directions.

Methods:

Five electronic databases (CINAHL, Medline, EMBASE, PsycINFO, and Cochrane Library) were searched. Titles and abstracts were independently screened by two of the authors and selected for inclusion. The full text of all potentially relevant studies were retrieved and assessed for eligibility, reporting and methodological quality, and risk of bias.

Findings:

Eight included studies were very heterogeneous in terms of study design, type of intervention, the population studied and instruments used to evaluate coping. All studies were judged to have a moderately high risk of bias. Six studies used cognitive behavioural therapy-based interventions. Two interventions (a peer-mentoring programme and cognitive behavioural therapy combined with motivational interviewing) showed significant treatment effects on maladaptive coping. Two cognitive behavioural therapy-based group programmes improved adaptive coping, but increases were either not sustained over time or no longer significant when compared to an active control.

Conclusions:

There is insufficient evidence to support practice recommendations strongly. Targeting specific subgroups of people who have experienced traumatic brain injury might allow the development of more effective coping interventions. Further, a more unified concept of coping in traumatic brain injury needs to be articulated allowing larger scale evaluations.

Brain and Serum Androsterone Is Elevated in Response to Stress in Rats with Mild Traumatic Brain Injury

Exposure to lateral fluid percussion (LFP) injury consistent with mild traumatic brain injury (mTBI) persistently attenuates acoustic startle responses (ASRs) in rats. Here, we examined whether the experience of head trauma affects stress reactivity. Male Sprague-Dawley rats were matched for ASRs and randomly assigned to receive mTBI through LFP or experience a sham surgery (SHAM). ASRs were measured post injury days (PIDs) 1, 3, 7, 14, 21, and 28. To assess neurosteroids, rats received a single 2.0 mA, 0.5 s foot shock on PID 34 (S34), PID 35 (S35), on both days (2S), or the experimental context (CON). Levels of the neurosteroids pregnenolone (PREG), allopregnanolone (ALLO), and androsterone (ANDRO) were determined for the prefrontal cortex, hippocampus, and cerebellum. For 2S rats, repeated blood samples were obtained at 15, 30, and 60 min post-stressor for determination of corticosterone (CORT) levels after stress or context on PID 34. Similar to earlier work, ASRs were severely attenuated in mTBI rats without remission for 28 days after injury. No differences were observed between mTBI and SHAM rats in basal CORT, peak CORT levels or its recovery. In serum and brain, ANDRO levels were the most stress-sensitive. Stress-induced ANDRO elevations were greater than those in mTBI rats. As a positive allosteric modulator of gamma-aminobutyric acid (GABA_A) receptors, increased brain ANDRO levels are expected to be anxiolytic. The impact of brain ANDRO elevations in the aftermath of mTBI on coping warrants further elaboration.

Brain network dysregulation, emotion, and complaints after mild traumatic brain injury

OBJECTIVES

To assess the role of brain networks in emotion regulation and post-traumatic complaints in the sub-acute phase after non-complicated mild traumatic brain injury (mTBI).

EXPERIMENTAL DESIGN

Fifty-four patients with mTBI (34 with and 20 without complaints) and 20 healthy controls (group-matched for age, sex, education, and handedness) were included. Resting-state fMRI was performed at four weeks post-injury. Static and dynamic functional connectivity were studied within and between the default mode, executive (frontoparietal and bilateral frontal network), and salience network. The hospital anxiety and depression scale (HADS) was used to measure anxiety (HADS-A) and depression (HADS-D).

PRINCIPAL OBSERVATIONS

Regarding within-network functional connectivity, none of the selected brain networks were different between groups. Regarding between-network interactions, patients with complaints exhibited lower functional connectivity between the bilateral frontal and salience network compared to patients without complaints. In the total patient group, higher HADS-D scores were related to lower functional connectivity between the bilateral frontal network and both the right frontoparietal and salience network, and to higher connectivity between the right frontoparietal and salience network. Furthermore, whereas higher HADS-D scores were associated with lower connectivity within the parietal midline areas of the bilateral frontal network, higher HADS-A scores were related to lower connectivity within medial prefrontal areas of the bilateral frontal network.

CONCLUSIONS

Functional interactions of the executive and salience networks were related to emotion regulation and complaints after mTBI, with a key role for the bilateral frontal network. These findings may have implications for future studies on the effect of psychological interventions.

Complementary and alternative medicine (CAM) following traumatic brain injury (TBI): Opportunities and challenges

Traumatic brain injury (TBI) is highly prevalent and occurs in a variety of populations. Because of the complexity of its sequelae, treatment strategies pose a challenge. Given this complexity, TBI provides a unique target of opportunity for complementary and alternative medicine (CAM) treatments. The present review describes and discusses current opportunitites and challenges associated with CAM research and clinical applications in civilian, veteran and military service populations. In addition to a brief overview of CAM, the translational capacity from basic to clinical research to clinical practice will be described. Finally, a systematic approach to developing an adoptable evidence base, with proof of effectiveness based on the literature will be discussed. Inherent in this discussion will be the methodological and ethical challenges associated with CAM research in those with TBI and associated comorbidities, specifically in terms of how these challenges relate to practice and policy issues, implementation and dissemination. This article is part of a Special Issue entitled SI:Brain injury and recovery.

Current status of fluid biomarkers in mild traumatic brain injury

Mild traumatic brain injury (mTBI) affects millions of people annually and is difficult to diagnose. Mild injury is insensitive to conventional imaging techniques and diagnoses are often made using subjective criteria such as self-reported symptoms. Many people who sustain a mTBI develop persistent post-concussive symptoms. Athletes and military personnel are at great risk for repeat injury which can result in second impact syndrome or chronic traumatic encephalopathy. An objective and quantifiable measure, such as a serum biomarker, is needed to aid in mTBI diagnosis, prognosis, return to play/duty assessments, and would further elucidate mTBI pathophysiology. The majority of TBI biomarker research focuses on severe TBI with few studies specific to mild injury. Most studies use a hypothesis-driven approach, screening biofluids for markers known to be associated with TBI pathophysiology. This approach has yielded limited success in identifying markers that can be used clinically, additional candidate biomarkers are needed. Innovative and unbiased methods such as proteomics, microRNA arrays, urinary screens, autoantibody identification and phage display would complement more traditional approaches to aid in the discovery of novel mTBI biomarkers.

Preinjury resilience and mood as predictors of early outcome following mild traumatic brain injury

There is significant heterogeneity in outcomes following mild traumatic brain injury (mTBI). While several host factors (age, gender, and preinjury psychiatric history) have been investigated, the influence of preinjury psychological resilience and mood status in conjunction with mild TBI remains relatively unexplored. Euthymic mood and high resilience are potentially protective against anxiety and postconcussion symptoms, but their relative contributions are currently unknown. This prospective study obtained preinjury estimates of resilience and mood measures in addition to measures of anxiety (Acute Stress Disorder Scale and PTSD-Checklist-Civilian form) and postconcussion symptom severity (Rivermead Post Concussion Symptoms Questionnaire) <24 hours (Baseline), 1 week, and 1 month postinjury in patients with either mTBI (n=46) or a comparison group with orthopedic injuries not involving the head (OI, n=29). The groups did not differ on preinjury resilience or mood status at baseline, but differed significantly on measures of anxiety and postconcussion symptom severity at each subsequent study occasion. Multivariate linear regression analyses were conducted to determine if preinjury resilience and mood were significant contributors to anxiety and postconcussion symptoms during the first month postinjury after accounting for other known host factors (e.g., age at injury, gender, and education). Injury group and preinjury mood status were significant predictors for all three dependent variables at each study occasion (all p<0.007). Preinjury resilience showed a positive trend only for acute stress severity at baseline, but demonstrated significant prediction of all three dependent measures at one week and one month postinjury. These results suggest that preinjury depressed mood and resilience are significant contributors to the severity of postinjury anxiety and postconcussion symptoms, even after accounting for effects of other specific host factors.

The relations among cognitive impairment, coping style, and emotional adjustment following traumatic brain injury

OBJECTIVE

To examine the direct, mediated, and moderated associations among cognition, coping, and emotional adjustment following traumatic brain injury (TBI).

DESIGN

Cross-sectional, single-group design.

PARTICIPANTS

Ninety-seven participants with mild to severe TBI recruited from their rehabilitation hospital and assessed on average 19 months postinjury.

MEASURES

The BIRT Memory and Information Processing Battery, Doors Test from the Doors and People Test, Hayling Sentence Completion Test, Controlled Oral Word Association Test, Trail Making Test, Digit Span, Symbol Digit Modalities Test-Oral Version, Hospital Anxiety and Depression Scale, and the Coping Scale for Adults.

RESULTS

Poorer performance on measures of memory, executive functions, and attention and information processing was associated with greater levels of self-reported depression and anxiety. No mediated relation was found between cognition and emotional adjustment. However, the use of adaptive coping strategies was found to moderate the relation between the Hayling A-a measure of information processing speed-and self-reported depression.

CONCLUSIONS

Greater impairments in cognition directly predicted higher levels of anxiety and depression following TBI. In addition, the results suggest that the use of adaptive coping strategies has a greater effect on levels of depression for individuals with poor information processing speed.

Coping strategies as a predictor of post-concussive symptoms in children with mild traumatic brain injury versus mild orthopedic injury

This study examined whether children's coping strategies are related to post-concussive symptoms following mild traumatic brain injury (TBI) versus orthopedic injury (OI). Participants were 8- to 15-year-old children with mild TBI (n = 167) or OI (n = 84). They rated their current preferred coping strategies and post-injury symptoms at 2 weeks (baseline) and 1, 3, and 12 months post-injury. Children's reported use of coping strategies did not vary significantly over time, so their baseline coping ratings were examined as predictors of post-concussive symptoms across time. Self-ratings of symptoms were positively related to emotion-focused strategies and negatively related to problem-focused engagement after both mild TBI and OI. Higher problem-focused disengagement predicted larger group differences in children's ratings of symptoms, suggesting that problem-focused disengagement moderates the effects of mild TBI. Coping strategies collectively accounted for approximately 10-15% of the variance in children's post-concussive symptoms over time. The findings suggest that coping may play an important role in accounting for children's perceptions of post-concussive symptoms after mild TBI.

A meta-analytic review of the emotional symptoms associated with mild traumatic brain injury

Given the prevalence of mild traumatic brain injury (mTBI) and enduring subjective complaints known as postconcussion symptoms (PCS), it is important to investigate the nature and extent of these difficulties. This study used meta-analytic techniques to integrate the available information on the emotional symptoms associated with mTBI. Small effect sizes were found across all domains (depression, anxiety, coping, and psychosocial disability); however, significance depended upon the weighting method employed. The results indicate that mTBI had a small to negligible effect on emotional symptom reporting. This has implications for the etiology of PCS, the delivery of therapeutic interventions, and medico-legal disputations.

Functional Status, Chronic Stress, and Cortisol Response After Mild-to-Moderate Traumatic Brain Injury

It is well known that individuals experience difficulties with depressive symptoms and functional status after traumatic brain injury. However, it is unclear what the relationship is between these 2 phenomena and whether there is a biological explanation for. In this secondary analysis, we examined whether depressive symptoms explained postinjury functional status and whether chronic stress and salivary cortisol influenced this relationship. Participants included 75 persons within 24 months of their injury dates who were evaluated or treated in specialty clinics. All participants and a family member or significant other completed survey data, and 50 of the participants provided cortisol data. Results indicated that chronic stress, measured using Cohen's Perceived Stress Scale, completely mediated the relationship between depressive symptoms, measured using the Center for Epidemiological Studies Depression Scale, and psychological functioning, measured using the Patient Competency Rating Scale. Furthermore, those who provided cortisol data displayed hypocortisolemia in their 12-hr profile. Results from this analysis suggest that interventions focused on addressing the chronic stress experience may be important in limiting depressive symptoms and improving psychological functioning. Longitudinal study of this phenomenon is required to understand the progression of chronic stress after traumatic brain injury.

Community integration, social support and life satisfaction in relation to symptoms 3 years after mild traumatic brain injury

PRIMARY OBJECTIVE

To investigate the relation between psychosocial functioning (community integration, life satisfaction and social support) and symptoms (post-concussion, post-traumatic stress and depression) in persons with mild traumatic brain injury (MTBI) 3 years after the trauma.

METHODS

Population-based follow-up study of 163 patients. At follow-up, an assessment of community integration, social support, life satisfaction and symptoms was made.

RESULTS

Total score of Community Integration Questionnaire (CIQ) was negatively correlated to total score of the Rivermead Post-Concussion Symptoms Questionnaire (RPQ, r = -0.270, p < 0.001) and to total score of the Beck Depression Inventory (BDI, r = -0.332, p < 0.001). Life satisfaction (LiSat-11) was negatively correlated to the RPQ (r = -0.459, p < 0.001), to total score of the Impact of Event Scale (IES, r = -0.365, p < 0.001) and to the BDI (r = -0.642, p < 0.001). Low levels of life satisfaction were common at follow-up.

CONCLUSIONS

A large proportion of the individuals with MTBI experienced both psychosocial difficulties, with low levels of life satisfaction in particular and symptoms (post-concussion, post-traumatic stress and depression) 3 years after trauma. Since the possibility of pre-injury factors contributing to the condition at follow-up cannot be ruled out, the study indicates that all these factors should be taken into consideration in the management of persons with MTBI.

Correlates of persistent postconcussional disorder: DSM-IV criteria versus ICD-10

Controversy surrounding the causation of symptom complaints after mild traumatic brain injury (MTBI) is reflected by the existence of alternative diagnostic criteria for postconcussional syndrome (PCS) in the International Classification of Diseases (ICD) and postconcussional disorder (PCD) in the Diagnostic and Statistical Manual of Mental Disorders-4th edition (DSM-IV). Previous studies of persisting symptoms have employed various symptom checklists rather than uniform criteria-based diagnoses. This is the first prospective study of persisting symptom complaints using the formal diagnostic criteria for PCD and PCS and comparing these criteria sets in terms of prevalence, relationship to potential compensation, and emotional/functional status. In this prospective study, an unselected series of adults with uncomplicated MTBI (N = 139) was assessed at 6 months postinjury with a brief neuropsychological battery and measures of psychiatric symptoms/disorders, social support/community integration, health-related quality of life, and global outcome. In parallel analyses, participants with PCD/PCS were compared to those without the disorder. Potential compensation was an equally significant factor in both criteria sets. Persistent PCS criteria were met 3.1 times more frequently than persistent PCD criteria. Significant racial differences in fulfilling PCD/PCS criteria were found. No differences in emotional/functional status patterns or global outcome were found between the criteria sets except for minor dissimilarities in the social/community integration domain. The results demonstrate that despite large differences in the frequency of patients meeting the two diagnostic criteria sets, a clear basis for preferring either the PCD or PCS criteria remains to be determined.

One-year follow-up of patients with mild traumatic brain injury: occurrence of post-traumatic stress-related symptoms at follow-up and serum levels of cortisol, S-100B and neuron-specific enolase in acute phase

OBJECTIVE

To investigate serum levels of cortisol (a biochemical marker of stress), S-100B and neuron-specific enolase (two biochemical markers of brain tissue injury), in acute phase in mild traumatic brain injury patients and the occurrence of post-traumatic stress-related symptoms 1 year after the trauma.

METHODS

Blood samples were taken in patients (n = 88) on admission and approximately 7 hours later for analysis. Occurrence of post-traumatic stress-related symptoms was assessed for 69 patients using items from the Impact of Event Scale questionnaire (IES) at follow-up at 15 +/- 4 months after the injury.

RESULTS

Serum levels of cortisol were more increased in the first sample (cortisol/1, 628.9 +/- 308.9 nmol L-1) than in the second blood sample (cortisol/2, 398.2 +/- 219.4 nmol L-1). The difference between these samples was statistically significant (p < 0.001). Altogether 12 patients (17%) showed post-traumatic stress related symptoms at the time of the follow-up. Stepwise forward logistic regression analysis of symptoms and serum concentrations of markers revealed that only S-100B in the second sample was statistically significantly (p < 0.05) associated to symptoms (three symptoms of the avoidance sub-set of IES).

CONCLUSION

A major increase in serum concentrations of cortisol indicates that high stress levels were reached by the patients, in particular shortly ( approximately 3 hours) after the trauma. The association between the occurrence of post-traumatic stress related symptoms and serum levels of S-100B (generally considered as a biochemical marker of brain injury) seem to reflect the complexity of interactions between brain tissue injury and the ensemble of stress reactions.

Postconcussional disorder: Are the DSM-IV criteria an improvement over the ICD-10?

Little is known about the characteristics and outcomes of patients diagnosed with postconcussional disorder (PCD) under the provisionally proposed criteria in the DSM-IV and how they differ from patients diagnosed with postconcussional syndrome (PCS) under the International Classification of Diseases, 10th edition clinical (ICD-10) criteria. This study investigated differences in outcome based on a diagnosis of PCD (DSM-IV) versus PCS (ICD-10 clinical criteria) as to which criteria set might be preferred for clinical practice. A consecutive series of adult patients with mild (N = 319) to moderate (N = 21) traumatic brain injury was assessed at 3 months postinjury with a brief neuropsychological battery and measures of specific outcome domains. In two separate series of analyses, patients with PCD were compared with those without PCD, and those with PCS were compared with those without PCS. Although the two criteria sets resulted in markedly different incidence rates, there was no substantial pattern of differences between the DSM-IV and ICD-10 in the outcome domains of psychiatric symptoms and disorders, social and community integration, health-related quality of life, or global outcome as measured by the Glasgow Outcome Scale-Extended. In spite of significant differences between the two diagnostic criteria sets and different incidence rates for PCD/PCS, outcome in all measured domains was very similar at 3 months postinjury. There is no compelling evidence, based on these outcome domains, to suggest which of the two diagnostic criteria sets should be clinically preferred.

Neuropsychological dysfunction in bipolar affective disorder: a critical opinion

Data from the imaging literature have led to suggestions that permanent structural brain changes may be associated with bipolar disorder. Individuals diagnosed with bipolar disorder display deficits on a range of neuropsychological tasks in both the acute and euthymic phases of illness, and correlations between experienced number of affective episodes and task performance are commonly reported. These findings have renewed interest in the neuropsychological profile of individuals with bipolar disorder, with deficits of attention, learning and memory, and executive function, asserted to be present. This paper critically reviews five different potential causes of neurocognitive dysfunction in bipolar disorder: (i) iatrogenic, (ii) acute functional changes associated with depression or mania, (iii) permanent structural lesions of a neurodegenerative origin, (iv) permanent structural lesions that are neurodevelopmental in origin, and (v) permanent functional changes that are most likely genetic in origin. Although the potential cognitive effects of residual symptomatology and long-term medication use cannot be entirely excluded, we conclude that functional changes associated with genetically driven population variation in critical neural networks underpin both the neurocognitive and affective symptoms of bipolar disorder. The philosophical implications of this conclusion for neuropsychology are briefly discussed.

Factors moderating neuropsychological outcomes following mild traumatic brain injury: a meta-analysis

There continues to be debate about the long-term neuropsychological impact of mild traumatic brain injury (MTBI). A meta-analysis of the relevant literature was conducted to determine the impact of MTBI across nine cognitive domains. The analysis was based on 39 studies involving 1463 cases of MTBI and 1191 control cases. The overall effect of MTBI on neuropsychological functioning was moderate (d = .54). However, findings were moderated by cognitive domain, time since injury, patient characteristics, and sampling methods. Acute effects (less than 3 months postinjury) of MTBI were greatest for delayed memory and fluency (d = 1.03 and .89, respectively). In unselected or prospective samples, the overall analysis revealed no residual neuropsychological impairment by 3 months postinjury (d = .04). In contrast, clinic-based samples and samples including participants in litigation were associated with greater cognitive sequelae of MTBI (d = .74 and .78, respectively at 3 months or greater). Indeed, litigation was associated with stable or worsening of cognitive functioning over time. The implications and limitations of these findings are discussed.

Acute stressors and cortisol responses: a theoretical integration and synthesis of laboratory research

This meta-analysis reviews 208 laboratory studies of acute psychological stressors and tests a theoretical model delineating conditions capable of eliciting cortisol responses. Psychological stressors increased cortisol levels; however, effects varied widely across tasks. Consistent with the theoretical model, motivated performance tasks elicited cortisol responses if they were uncontrollable or characterized by social-evaluative threat (task performance could be negatively judged by others), when methodological factors and other stressor characteristics were controlled for. Tasks containing both uncontrollable and social-evaluative elements were associated with the largest cortisol and adrenocorticotropin hormone changes and the longest times to recovery. These findings are consistent with the animal literature on the physiological effects of uncontrollable social threat and contradict the belief that cortisol is responsive to all types of stressors.

Predictors of postconcussion symptom complex in community dwelling male veterans

The presence of a persistent postconcussion symptom complex (PPCSC) was examined in a non-referred sample of male veterans with a history of mild head injury and a comparison group without a history of head injury. Hierarchical logistic regression procedures were used to determine possible predictors of PPCSC using variables supported by previous research (i.e., preexisting psychiatric difficulties, demographic and social support variables, and history of an accidental injurious event). Although PPCSC was common in all groups (23% of the total sample), a significantly greater proportion of individuals in the mild head injury with loss of consciousness group (37.2%) had PPCSC compared with three other groups (head injury without loss of consciousness = 26.1%; motor vehicle accident without head injury = 23%; and control = 17.3%). However, the most salient predictors of PPCSC were early life psychiatric difficulties such as anxiety or depression, limited social support, lower intelligence, and interactions among these variables. The predictive value of loss of consciousness was significant, but low (1.4% of unique variance). The findings provide support for the premise that PPCSC is mediated in part by individual resilience, preexisting psychological status, and psychosocial support.

Neuropsychological functioning in chronic fatigue syndrome: a review

OBJECTIVE

In this paper we review critically the current status of neurocognitive studies in patients with chronic fatigue syndrome (CFS).

METHOD

CFS literature was monitored as part of a large research project which involved several neuropsychological and psychopathological studies. The literature survey was the result of several consecutive searches on Medline and PsycInfo databases.

RESULTS

The neurocognitive studies are reviewed in terms of scientificaly accepted aspects of attention and memory. In addition, we review possible explanations for cognitive dysfunction in CFS. This is preceded with a discussion of the methodological limitations that are considered to explain inconcistencies across neuropsychological studies in CFS.

CONCLUSION

The current research shows that slowed processing speed, impaired working memory and poor learning of information are the most prominent features of cognitive dysfunctioning in patients with CFS. Furthermore, to this date no specific pattern of cerebral abnormalities has been found that uniquely characterizes CFS patients. There is no overwhelming evidence that fatigue is related to cognitive performance in CFS, and researchers agree that their performance on neuropsychological tasks is unlikely to be accounted solely by the severity of the depression and anxiety.

Assessment of executive function in patients with mild traumatic brain injury

BACKGROUND

The nature of functional deficit after mild traumatic brain injury (TBI) defined by Glasgow Coma Score of 13-15 is not fully described. This study explored the sensitivity of several neuropsychological tests to identify sequelae of mild traumatic brain injury (TBI).

METHODS

Eleven adult patients with mild TBI admitted to a Level 1 trauma center were studied. The battery of tests included the Wechsler Intelligence Scale for Children -Revised: Mazes Subtest, Trails A and B, the Boston Naming Test, The Multilingual Aphasia Examination: Controlled Oral Word Association Test, and the Paced Auditory Serial Addition Task.

RESULTS

Control subjects performed significantly better than patients with mild TBI on Trails A and B, the Controlled Oral Word Association Test, and Paced Auditory Serial Addition Task (subtests 2-4). No significant differences in performances between patients and controls was found for the Wechsler Intelligence Scale for Children -Revised: Mazes Subtest, Boston Naming Test, and Paced Auditory Serial Addition Task Subtest 1.

CONCLUSION

The results suggest that tests of specific frontal lobe executive functions are valuable in diagnosing and monitoring recovery from mild TBI.

Depression after mild traumatic brain injury: a review of current research

Research pertaining to the occurrence of depression and/or depression symptomatology after a Mild Traumatic Brain Injury (MTBI) was reviewed. We found that methodological differences such as the criteria used to assess MTBI and depression, time that elapsed since brain injury, and control group variations confounded comparisons across studies. Nevertheless, the studies are consistent with at least a 35% prevalence of, and left frontal damage with depression after MTBI, an overlap of symptoms of depression and Postconcussion Syndrome (PCS), and indicate that depression can continue for many years following the injury. Our conclusion is that MTBI is the triggering event for a set of pathophysiological changes and a concomitant depressive episode in a vulnerable subset of the population. Due to a paucity of research, it cannot be definitively concluded that the underlying substrates of depression seen after MTBI and clinical depression are the same. Implications for future investigations are discussed.