Neuropsychological and physiological correlates of fatigue following traumatic brain injury

Traumatic brain injury and sleep in military and veteran populations: A literature review

BACKGROUND

Traumatic brain injury (TBI) is a hallmark of wartime injury and is related to numerous sleep wake disorders (SWD), which persist long term in veterans. Current knowledge gaps in pathophysiology have hindered advances in diagnosis and treatment.

OBJECTIVE

We reviewed TBI SWD pathophysiology, comorbidities, diagnosis and treatment that have emerged over the past two decades.

METHODS

We conducted a literature review of English language publications evaluating sleep disorders (obstructive sleep apnea, insomnia, hypersomnia, parasomnias, restless legs syndrome and periodic limb movement disorder) and TBI published since 2000. We excluded studies that were not specifically evaluating TBI populations.

RESULTS

Highlighted areas of interest and knowledge gaps were identified in TBI pathophysiology and mechanisms of sleep disruption, a comparison of TBI SWD and post-traumatic stress disorder SWD. The role of TBI and glymphatic biomarkers and management strategies for TBI SWD will also be discussed.

CONCLUSION

Our understanding of the pathophysiologic underpinnings of TBI and sleep health, particularly at the basic science level, is limited. Developing an understanding of biomarkers, neuroimaging, and mixed-methods research in comorbid TBI SWD holds the greatest promise to advance our ability to diagnose and monitor response to therapy in this vulnerable population.

The Fatigue and Altered Cognition Scale among SARS-CoV-2 Survivors: Psychometric Properties and Item Correlations with Depression and Anxiety Symptoms

Background/Objectives: This study examined the psychometric properties of the Fatigue and Altered Cognition Scale (FACs) among adult COVID-19 survivors and its unique ability to assess symptomology not accounted for by measures of depression and anxiety. Methods: COVID-19 survivors completed an online survey that included the FACs, a measure of brain fog and central fatigue with 20 items rated on a digital-analog scale. Useable data from 559 participants were analyzed to test the two-factor structure of the FACs, test for measurement invariance by sex and device was used to complete the survey (hand-held, computer), and item correlations with symptoms of depression and anxiety were examined. Results: The two-factor structure of the FACs replicated, supporting the separate assessments of brain fog and fatigue, χ2(164) = 1028.363, p < 0.001, CFI = 0.934, TLI = 0.923, RMSEA = 0.097, SRMR = 0.053. The FACs exhibited invariance at the scalar level, indicating item and factor integrity regardless of sex and device type. Using a correlation > 0.70 as a criterion (i.e., indicating more than 50% shared variance between two items), items on the FACs (assessing fatigue and lack of energy) were highly correlated with feeling tired or having little energy on the depression measure. No other items correlated with any anxiety symptom larger than 0.70. Conclusions: The FACs appears to be a psychometrically sound and efficient measure for use with COVID-19 survivors, assessing symptoms of brain fog and central fatigue that are not attributable to symptoms assessed by established measures of depression and anxiety.

Fatigue in patients with acquired brain damage

Fatigue is a complex, multidimensional syndrome that is prevalent in patients with acquired brain damage and has a negative impact on the neurorehabilitation process. It presents from early stages after the injury, and may persist over time, regardless of whether sequelae have resolved. Fatigue is conditioned by upper neuronal circuits, and is defined as an abnormal perception of overexertion. Its prevalence ranges from 29% to 77% after stroke, from 18% to 75% after traumatic brain injury, and from 47% to 97% after brain tumours. Fatigue is associated with factors including female sex, advanced age, dysfunctional families, history of specific health conditions, functional status (eg, fatigue prior to injury), comorbidities, mood, secondary disability, and the use of certain drugs. Assessment of fatigue is fundamentally based on such scales as the Fatigue Severity Scale (FSS). Advances have recently been made in imaging techniques for its diagnosis, such as in functional MRI. Regarding treatment, no specific pharmacological treatment currently exists; however, positive results have been reported for some conventional neurorehabilitation therapies, such as bright light therapy, neurofeedback, electrical stimulation, and transcranial magnetic stimulation. This review aims to assist neurorehabilitation professionals to recognise modifiable factors associated with fatigue and to describe the treatments available to reduce its negative effect on patients.

Efficient assessment of brain fog and fatigue: Development of the Fatigue and Altered Cognition Scale (FACs)

Debilitating symptoms of fatigue and accompanying "brain fog" are observed among patients with various chronic health conditions. Unfortunately, an efficient and psychometrically sound instrument to assess these co-occurring symptoms is unavailable. Here, we report the development and initial psychometric properties of the Fatigue and Altered Cognition Scale (the FACs), a measure of self-reported central fatigue and brain fog. Traumatic brain injury (TBI) was chosen to model and develop the FACs due to research team expertise and established links between TBI and the symptom complex. Potential items were generated by researchers and clinicians with experience treating these symptoms, drawing from relevant literature and review of patient responses to measures from past and current TBI studies. The 20 candidate items for the FACs-ten each to assess altered cognition (i.e., brain fog) and central fatigue-were formatted on an electronic visual analogue response scale (eVAS) via an online survey. Demographic information and history of TBI were obtained. A total of 519 participants consented and provided usable data (average age = 40.23 years; 73% female), 204 of whom self-reported a history of TBI (75% reported mild TBI). Internal consistency and reliability values were calculated. Confirmatory factor analysis (CFA) examined the presumed two-factor structure of the FACs and a one-factor solution for comparison. A measurement invariance test of the two latent constructs (altered cognition, fatigue) among participants with and without TBI was conducted. All items demonstrated normal distribution. Cronbach's alpha coefficients indicated good internal consistency for both factors (α's = .95). Omega reliability values were favorable (α's = .95). CFA supported the presumed two-factor model and item loadings which outperformed the one-factor model. Measurement invariance found the two-factor structure was consistent between the two groups. Implications of these findings, study limitations, and potential use of the FACs in clinical research and practice are discussed.

Stability and Change in Biopsychosocial Factors Associated With Fatigue 6 and 12 Months After Traumatic Brain Injury: An Exploratory Multilevel Study

OBJECTIVE

To explore factors associated with stability and change in fatigue from 6 to 12 months following traumatic brain injury (TBI).

SETTING

Combined in- and outpatient acute care and postacute rehabilitation settings.

PARTICIPANTS

A total of 103 patients with confirmed intracranial injury were assessed 6 and/or 12 months following TBI.

DESIGN

A prospective observational study with repeated measures at 2 time points, analyzed with a hybrid mixed-effects model.

MAIN MEASURES

Primary outcomes were the fatigue factor derived from items from several fatigue patient-reported outcome measures (PROMs; Fatigue Severity Scale, Chalder Fatigue Scale, Giessen Subjective Complaints List-fatigue subscale, and Rivermead Post-Concussion Symptoms Questionnaire-fatigue item) Secondary outcomes were PROMs relating to pain, somatic and psychological distress, insomnia, sleepiness, personality traits, optimism, resilience, behavioral activation and inhibition, and loneliness, as well as neuropsychological measures. Demographic variables and injury severity characteristics were included as covariates.

RESULTS

In multilevel regression, female sex, years of education, and 3 factors related to injury severity, somatic vulnerability, and psychosocial robustness were all significantly associated with variation in fatigue between subjects, and explained 61% of the variance in fatigue that was due to stable between-subject differences. Fatigue levels declined significantly over time. Changes in pain severity, somatic symptom burden, psychological distress, and behavioral inhibition were positively associated with changes in fatigue, explaining 22% of the variance in fatigue within subjects.

CONCLUSIONS

The study demonstrated that several previously implicated factors show robust effects in distinguishing individuals with TBI on levels of fatigue, but only a few show additional within-subject associations across time. Pain severity, somatic symptom burden, psychological distress, and behavioral inhibition correlated with fatigue across time, implicating these factors as crucial targets for rehabilitation of patients with TBI who suffer from persistent fatigue.

Fatigue in young patients with acquired brain injury in the rehabilitation setting: Categorizing and interpreting fatigue severity levels

PURPOSE

Fatigue in patients with acquired brain injury (ABI) is common. However, to better target fatigue, clear ways to categorize/interpret fatigue-severity in individual patients are lacking. This study aims to determine/categorize fatigue severity among children, adolescents, and young adults with ABI.

METHODS

This cross-sectional study included young patients admitted to outpatient rehabilitation and their parents. To determine fatigue, the PedsQL™Multidimensional-Fatigue-Scale was used (MFS, scores 0-100, lower scores = higher fatigue, patient-/parent-reported). Based on scores from a reference population, four categories were formed: "1 = no/little fatigued" to "4 = severely-more fatigued."

RESULTS

All scores were lower than those from the reference population, with comparisons in the adolescent and young adult groups reaching statistical significance (p < .05). The proportions of patients in category 4 were: 9%/50%/58% among children/adolescents/young adults, showing that many patients were "severely-more fatigued"-than the reference population.

CONCLUSIONS

Measuring fatigue and categorizing fatigue severity looks promising for clinical practice and could help to better target fatigue.

Reducing fatigue following acquired brain injury: A feasibility study of high intensity interval training for young adults

The aim was to evaluate feasibility of high-intensity interval training (HIIT) in fatigued adults (20-40 years old) with acquired brain injury (ABI). A prospective pre-post single-arm intervention trial was conducted, including 6-8 months follow-up assessment and interview. Intervention was 18 sessions of intermittent exercise on a cycle ergometer over six weeks. Six out of ten participants without motor impairments completed the intervention (all females, mean age = 30.2 years, months post-injury = 22). On average, participants attended 88% of sessions and achieved high intensity (93% of max heart rate). VO_2max improved by 0.53 l/min (SD = 0.29), and participants continued exercising post-intervention. All participants were satisfied with HIIT, were more inclined to exercise, and reported positive effects of exercising for self-management of fatigue. Three sessions a week were demanding to some participants. Findings support feasibility of HIIT as a promising intervention for young adults with post-ABI fatigue.

Cognitive-Linguistic outcome in moderate to severe diffuse axonal injury and association with fatigue

PURPOSE

Individuals with traumatic brain injury (TBI) often have persistent cognitive-linguistic deficits that negatively influence their life. Our objective was to examine the cognitive-linguistic outcome in individuals with moderate to severe diffuse axonal injury (DAI) with a novel test battery. As fatigue is a common symptom affecting the lives of individuals with DAI, we also wanted to assess whether the self-reported fatigue was associated with cognitive-linguistic abilities.

METHODS

Selected cognitive-linguistic subtests of the Finnish KAT test and The Mental Fatigue Scale (MFS) were applied to 48 adults with moderate to severe DAI and 27 healthy controls. The majority of the participants with DAI were in the chronic stage. The groups were compared using ANCOVA. Linear regressions were used to analyze the association between MFS and cognitive-linguistic outcomes.

RESULTS

The participants with DAI had significantly poorer scores than the controls in most cognitive-linguistic variables and reported significantly more fatigue. Two of the four cognitive-linguistic composite variables were associated with the degree of self-reported fatigue.

CONCLUSIONS

Cognitive-linguistic deficits are common in individuals with moderate to severe DAI, and The Finnish KAT test is a valuable tool to detect those. Fatigue was associated with linguistic working memory and language production.

Fatigue after acquired brain injury impacts health-related quality of life: an exploratory cohort study

This study aimed to identify the consequences of fatigue, fatigability, cognitive and executive functioning, and emotional state on health-related quality of life (HRQoL) in a clinical group of outpatients after acquired brain injury (ABI). This cross-sectional retrospective study included assessing outpatients at a rehabilitation clinic with WAIS-III working memory and coding subtests, and self-rating scales (Fatigue Impact Scale, Dysexecutive Questionnaire, Hospital Anxiety and Depression Scale, and the dimension of health-related quality of life from EQ-5D-3L). The predictive variables were investigated using a binary logistic regression with HRQoL as the dependent variable. Descriptive statistics and correlations were analyzed. Participants reported a lower than average HRQoL (95%), fatigue (90%), and executive dysfunction (75%). Fatigue had a significant impact and explained 20–33% of the variance in HRQoL with a moderate significance on depression (p = 0.579) and executive dysfunction (p = 0.555). Cognitive and executive function and emotional state showed no association with HRQoL. A lower HRQoL, as well as fatigue and cognitive and executive dysfunctions, are common after ABI, with fatigue is a partial explanation of a lower HRQoL.

Fatigue in patients with acquired brain damage

Fatigue is a complex, multidimensional syndrome that is prevalent in patients with acquired brain damage and has a negative impact on the neurorehabilitation process. It presents from early stages after the injury, and may persist over time, regardless of whether sequelae have resolved. Fatigue is conditioned by upper neuronal circuits, and is defined as an abnormal perception of overexertion. Its prevalence ranges from 29% to 77% after stroke, from 18% to 75% after traumatic brain injury, and from 47% to 97% after brain tumours. Fatigue is associated with factors including female sex, advanced age, dysfunctional families, history of specific health conditions, functional status (eg, fatigue prior to injury), comorbidities, mood, secondary disability, and the use of certain drugs. Assessment of fatigue is fundamentally based on such scales as the Fatigue Severity Scale (FSS). Advances have recently been made in imaging techniques for its diagnosis, such as in functional MRI. Regarding treatment, no specific pharmacological treatment currently exists; however, positive results have been reported for some conventional neurorehabilitation therapies, such as bright light therapy, neurofeedback, electrical stimulation, and transcranial magnetic stimulation. This review aims to assist neurorehabilitation professionals to recognise modifiable factors associated with fatigue and to describe the treatments available to reduce its negative effect on patients.

Self- and Parent-Reported Fatigue 7 Years After Severe Childhood Traumatic Brain Injury: Results of the Traumatisme Grave de l'Enfant Prospective Longitudinal Study

OBJECTIVE

To investigate presence of and factors associated with self- and parent-reported fatigue 7 years after severe childhood traumatic brain injury (TBI) in the prospective longitudinal study TGE (Traumatisme Grave de l'Enfant-severe childhood trauma).

METHODS

Self-reports and/or parent reports on the Multidimensional Fatigue Scale were collected for 38 participants (aged 7-22 years) 7 years after severe childhood TBI, and 33 controls matched for age, gender, and parental educational level. The data collected included sociodemographic characteristics, age at injury and injury severity scores, overall disability (Glasgow Outcome Scale Extended), intellectual outcome (Wechsler scales), and questionnaires assessing executive functions, health-related quality of life, behavior, and participation.

RESULTS

Fatigue levels were significantly worse in the TBI than in the control group, especially for cognitive fatigue. Correlations of reported fatigue with age at injury, gender, TBI severity, and intellectual ability were moderate and often not significant. Fatigue was significantly associated with overall level of disability (Glasgow Outcome Scale Extended) and with all questionnaires completed by the same informant.

CONCLUSION

High levels of fatigue were reported by 30% to 50% of patients 7 years after a severe childhood TBI. Reported fatigue explained more than 60% of the variance of reported health-related quality of life by the same informant (patient or parent).

Cognitive behavioural therapy versus health education for sleep disturbance and fatigue after acquired brain injury: A pilot randomised trial

BACKGROUND

Sleep disturbance and fatigue are highly prevalent after acquired brain injury (ABI) and are associated with poor functional outcomes. Cognitive behavioural therapy (CBT) is a promising treatment for sleep and fatigue problems after ABI, although comparison with an active control is needed to establish efficacy.

OBJECTIVES

We compared CBT for sleep disturbance and fatigue (CBT-SF) with a health education (HE) intervention to control for non-specific therapy effects.

METHODS

In a parallel-group, pilot randomised controlled trial, 51 individuals with traumatic brain injury (n = 22) and stroke (n = 29) and clinically significant sleep and/or fatigue problems were randomised 2:1 to 8 weeks of a CBT-SF (n = 34) or HE intervention (n = 17), both adapted for cognitive impairments. Participants were assessed at baseline, post-treatment, and 2 and 4 months post-treatment. The primary outcome was the Pittsburgh Sleep Quality Index; secondary outcomes included measures of fatigue, sleepiness, mood, quality of life, activity levels, self-efficacy and actigraphy sleep measures.

RESULTS

The CBT-SF led to significantly greater improvements in sleep quality as compared with HE, during treatment and at 2 months [95% confidence interval (CI) -24.83; -7.71], as well as significant reductions in fatigue maintained at all time points, which were not evident with HE (95% CI -1.86; 0.23). HE led to delayed improvement in sleep quality at 4 months post-treatment and in depression (95% CI -1.37; -0.09) at 2 months post-treatment. CBT-SF led to significant gains in self-efficacy (95% CI 0.15; 0.53) and mental health (95% CI 1.82; 65.06).

CONCLUSIONS

CBT-SF can be an effective treatment option for sleep disturbance and fatigue after ABI, over and above HE. HE may provide delayed benefit for sleep, possibly by improving mood.

TRIAL REGISTRATION

Australia New Zealand Clinical Trials Registry: ACTRN12617000879369 (registered 15/06/2017) and ACTRN12617000878370 (registered 15/06/2017).

Physical Activity Intolerance and Cardiorespiratory Dysfunction in Patients with Moderate-to-Severe Traumatic Brain Injury

Moderate-to-severe traumatic brain injury (TBI) is a chronic health condition with multi-systemic effects. Survivors face significant long-term functional limitations, including physical activity intolerance and disordered sleep. Persistent cardiorespiratory dysfunction is a potentially modifiable yet often overlooked major contributor to the alarmingly high long-term morbidity and mortality rates in these patients. This narrative review was developed through systematic and non-systematic searches for research relating cardiorespiratory function to moderate-to-severe TBI. The literature reveals patients who have survived moderate-to-severe TBI have ~ 25-35% reduction in maximal aerobic capacity 6-18 months post-injury, resting pulmonary capacity parameters that are reduced 25-40% for weeks to years post-injury, increased sedentary behavior, and elevated risk of cardiorespiratory-related morbidity and mortality. Synthesis of data from other patient populations reveals that cardiorespiratory dysfunction is likely a consequence of ventilator-induced diaphragmatic dysfunction (VIDD), which is not currently addressed in TBI management. Thus, cardiopulmonary exercise testing should be routinely performed in this patient population and those with cardiorespiratory deficits should be further evaluated for diaphragmatic dysfunction. Lack of targeted treatment for underlying cardiorespiratory dysfunction, including VIDD, likely contributes to physical activity intolerance and poor functional outcomes in these patients. Interventional studies have demonstrated that short-term exercise training programs are effective in patients with moderate-to-severe TBI, though improvement is variable. Inspiratory muscle training is beneficial in other patient populations with diaphragmatic dysfunction, and may be valuable for patients with TBI who have been mechanically ventilated. Thus, clinicians with expertise in cardiorespiratory fitness assessment and exercise training interventions should be included in patient management for individuals with moderate-to-severe TBI.

Growth Hormone Alters Brain Morphometry, Connectivity, and Behavior in Subjects with Fatigue after Mild Traumatic Brain Injury

Pituitary dysfunction with reduced growth hormone (GH) secretion is common in patients following traumatic brain injury (TBI), and these patients often develop chronic symptoms including fatigue and altered cognition. We examined 18 subjects with a history of mild TBI, fatigue, and insufficient GH secretion. Subjects received GH replacement in a year-long, double-blind, placebo-controlled, crossover study, and were assessed for changes in physical performance, body composition, resting energy expenditure, fatigue, sleep, mood, and neuropsychological status. Additionally, magnetic resonance imaging (MRI) was used to assess changes in brain structure and resting state functional connectivity. GH replacement resulted in decreased fatigue, sleep disturbance, and anxiety, as well as increased resting energy expenditure, improved body composition, and altered perception of submaximal effort when performing exercise testing. Associated brain changes included increased frontal cortical thickness and gray matter volume and resting state connectivity changes in regions associated with somatosensory networks. GH replacement altered brain morphology and connectivity and reduced fatigue and related symptoms in mild TBI patients. Additional studies are needed to understand the mechanisms causing TBI-related fatigue and symptom relief with GH replacement.

Anti-Pituitary and Anti-Hypothalamus Autoantibody Associations with Inflammation and Persistent Hypogonadotropic Hypogonadism in Men with Traumatic Brain Injury

Traumatic brain injury (TBI) and can lead to persistent hypogonadotropic hypogonadism (PHH) and poor outcomes. We hypothesized that autoimmune and inflammatory mechanisms contribute to PHH pathogenesis. Men with moderate-to-severe TBI (n = 143) were compared with healthy men (n = 39). The TBI group provided blood samples 1-12 months post-injury (n = 1225). TBI and healthy control (n = 39) samples were assayed for testosterone (T) and luteinizing hormone (LH) to adjudicate PHH status. TBI samples 1-6 months post-injury and control samples were assayed for immunoglobulin M (IgM)/immunoglobulin G (IgG) anti-pituitary autoantibodies (APA) and anti-hypothalamus autoantibodies (AHA). Tissue antigen specificity for APA and AHA was confirmed via immunohistochemistry (IHC). IgM and IgG autoantibodies for glial fibrillary acid protein (GFAP) (AGA) were evaluated to gauge APA and AHA production as a generalized autoimmune response to TBI and to evaluate the specificity of APA and AHA to PHH status. An inflammatory marker panel was used to assess relationships to autoantibody profiles and PHH status. Fifty-one men with TBI (36%) had PHH. An age-related decline in T levels by both TBI and PHH status were observed. Injured men had higher APA IgM, APA IgG, AHA IgM, AHA IgG, AGA IgM, and AGA IgG than controls (p < 0.0001 all comparisons). However, only APA IgM (p = 0.03) and AHA IgM (p = 0.03) levels were lower in the PHH than in the non-PHH group in multivariate analysis. There were no differences in IgG levels by PHH status. Multiple inflammatory markers were positively correlated with IgM autoantibody production. PHH was associated with higher soluble tumor-necrosis-factor receptors I/II, (sTNFRI, sTNFRII), regulated on activation, normal T-cell expressed and secreted (RANTES) and soluble interleukin-2-receptor-alpha (sIL-2Rα) levels. Higher IgM APA, and AHA, but not AGA, in the absence of PHH may suggest a beneficial or reparative role for neuroendocrine tissue-specific IgM autoantibody production against PHH development post-TBI.

Reward presentation reduces on-task fatigue in traumatic brain injury

While cognitive fatigue is experienced by up to 80% of individuals with traumatic brain injury (TBI), little is known about its neural underpinnings. We previously hypothesized that presentation of rewarding outcomes leads to cognitive fatigue reduction and activation of the striatum, a brain region shown to be associated with cognitive fatigue in clinical populations and processing of rewarding outcomes. We have demonstrated this in individuals with multiple sclerosis. Here, we tested this hypothesis in individuals with TBI. Twenty-one individuals with TBI and 24 healthy participants underwent functional magnetic resonance imaging. Participants performed a task during which they were presented with 1) the Outcome condition where they were exposed to monetary rewards, and 2) the No Outcome condition that served as the control condition and was not associated with monetary rewards. In accordance with our hypothesis, results showed that attainment of rewarding outcomes leads to cognitive fatigue reduction in individuals with TBI, as well as activation of the striatum. Specifically, we observed a significant group by condition interaction on fatigue scores driven by the TBI group reporting lower levels of fatigue after the Outcome condition. fMRI data revealed a significant main-effect of condition in regions previously implicated in outcome processing, while a significant group by condition interaction was observed in the left ventral striatum as revealed by a priori region of interest analysis. Results suggest that a salient motivator can significantly reduce fatigue and that outcome presentation leads to increased activation of the ventral striatum in TBI. These findings can inform the development of future non-pharmacological cognitive fatigue treatment methods and contribute to the growing body of evidence showing the association between cognitive fatigue and the striatum.

The history of pituitary dysfunction after traumatic brain injury

PURPOSE

To estimate the total number of articles on traumatic brain injury (TBI)-related hypopituitarism and patients (including children and adolescents) with such disorder that were published until now, particularly after the author's review published on April 2000.

METHODS

Review of the literature retrievable on PubMed.

RESULTS

TBI-related hypopituitarism accounts for 7.2% of the whole literature on hypopituitarism published during the 18 years and half between May 2000 and October 2018. As a result, the total number of patients with TBI-related hypopituitarism now approximates 2200. A number of patients, both adults and children, continue to be published as case reports. Articles, including reviews and guidelines, have been published in national languages in order to maximize locally the information on TBI-related hypopituitarism. TBI-related hypopituitarism has been also studied in animals (rodents, cats and dogs).

CONCLUSIONS

The interest for the damage suffered by anterior pituitary as a result of TBI continues to remain high both in the adulthood and childhood.

Sleep and fatigue after TBI

BACKGROUND

Whilst post traumatic brain injury fatigue (PTBIF) and sleep disturbance are common sequelae following brain injury, underlying mechanisms, and the potential for targeted interventions remain unclear.

OBJECTIVE

To present a review of recent studies exploring the epidemiology of PTBIF and sleep disturbance, the relationship and neuropsychological correlates of these issues, potential approaches to intervention, and implications for neurorehabilitation.

METHODS

A review of relevant literature was undertaken, with a focus on PTBIF relating to sleep disturbance, the neuropsychological correlates of these issues and implications for neurorehabilitation. This paper does not set out to provide a systematic review.

RESULTS

Multidimensional approaches to assessment and treatment of sleep disturbance and PTBIF are required.

CONCLUSIONS

There is a need for more robust findings in determining the complex nature of relationships between PTBIF, sleep disturbance, and correlates. Longitudinal prospective data is required to increase our understanding of the nature and course of PTBIF and sleep disturbance post TBI. Large scale clinical trials are required in evaluating the potential benefits of interventions.

Cognitive Behavior Therapy to Treat Sleep Disturbance and Fatigue After Traumatic Brain Injury: A Pilot Randomized Controlled Trial

OBJECTIVE

To evaluate the efficacy of adapted cognitive behavioral therapy (CBT) for sleep disturbance and fatigue in individuals with traumatic brain injury (TBI).

DESIGN

Parallel 2-group randomized controlled trial.

SETTING

Outpatient therapy.

PARTICIPANTS

Adults (N=24) with history of TBI and clinically significant sleep and/or fatigue complaints were randomly allocated to an 8-session adapted CBT intervention or a treatment as usual (TAU) condition.

INTERVENTIONS

Cognitive behavior therapy.

MAIN OUTCOME MEASURES

The primary outcome was the Pittsburgh Sleep Quality Index (PSQI) posttreatment and at 2-month follow-up. Secondary measures included the Insomnia Severity Index, Fatigue Severity Scale, Brief Fatigue Inventory (BFI), Epworth Sleepiness Scale, and Hospital Anxiety and Depression Scale.

RESULTS

At follow-up, CBT recipients reported better sleep quality than those receiving TAU (PSQI mean difference, 4.85; 95% confidence interval [CI], 2.56-7.14). Daily fatigue levels were significantly reduced in the CBT group (BFI difference, 1.54; 95% CI, 0.66-2.42). Secondary improvements were significant for depression. Large within-group effect sizes were evident across measures (Hedges g=1.14-1.93), with maintenance of gains 2 months after therapy cessation.

CONCLUSIONS

Adapted CBT produced greater and sustained improvements in sleep, daily fatigue levels, and depression compared with TAU. These pilot findings suggest that CBT is a promising treatment for sleep disturbance and fatigue after TBI.

A randomised control trial of walking to ameliorate brain injury fatigue: a NIDRR TBI model system centre-based study

Fatigue is one of the most commonly reported sequelae after traumatic brain injury (TBI). This study evaluated the impact of a graduated physical activity programme on fatigue after TBI. Using a prospective randomised single-blind crossover design, 123 individuals with TBI, over the age of 18, were enrolled. Interventions included a home-based walking programme utilising a pedometer to track daily number of steps at increasing increments accompanied by tapered coaching calls over a 12-week period. Nutritional counselling with the same schedule of coaching calls served as the control condition. Main outcome measures included: the Global Fatigue Index (GFI), the Barrow Neurological Institute (BNI) Fatigue Scale Overall Severity Index Score, and the Multidimensional Fatigue Inventory (MFI). Step counts improved over time regardless of group assignment. The walking intervention led to a decrease in GFI, BNI Total, and MFI General scores. Participants reported less fatigue at the end of the active part of the intervention (24 weeks) and after a wash out period (36 weeks) as measured by the BNI Overall. The study suggests that walking can be used as an efficient and cost-effective tool to improve fatigue in persons who have sustained a TBI.

Functional Changes after Recombinant Human Growth Hormone Replacement in Patients with Chronic Traumatic Brain Injury and Abnormal Growth Hormone Secretion

We explored the effects of recombinant human growth hormone (rhGH) replacement on physical and cognitive functioning in subjects with a moderate-to-severe traumatic brain injury (TBI) with abnormal growth hormone (GH) secretion. Fifteen individuals who sustained a TBI at least 12 months prior to study enrollment were identified as having abnormal GH secretion by glucagon stimulation testing (maximum GH response less than 8 ng/mL). Peak cardiorespiratory capacity, body composition, and muscle force testing were assessed at baseline and one year after rhGH replacement. Additionally, standardized neuropsychological tests that assess memory, processing speed, and cognitive flexibility, as well as self-report inventories related to depression and fatigue, were administered at baseline and 1 year after rhGH replacement. Comparison tests were performed with proper post hoc analyses. All analyses were carried out at α < 0.05. Peak O₂ consumption, peak oxygen pulse (estimate of cardiac stroke volume), and peak ventilation all significantly increased (p < 0.05). Maximal isometric and isokinetic force production were not altered. Skeletal muscle fatigue did not change but the perceptual rating of fatigue was reduced by ∼25% (p = 0.06). Cognitive performance did not change significantly over time, whereas self-reported symptoms related to depression and fatigue significantly improved. The observed changes suggest that rhGH replacement has a positive impact on cardiorespiratory fitness and a positive impact on perceptual fatigue in survivors of TBI with altered GH secretion.

Perceived Social Support and Its Impact on Mental Fatigue in Patients with Mild Traumatic Brain Injury

BACKGROUND

Although mental fatigue was well-recognized as one of the long-term consequences following mild traumatic brain injury (MTBI) that required ongoing support, evidences for the optimal management remained inadequate.

AIMS

To investigate the temporal profile of mental fatigue during the first year after MTBI and examine the impact of perceived social support on the recovery from post-MTBI fatigue.

STUDY DESIGN

Observational case-control study.

METHODS

This study was conducted among post-MTBI patients admitted to the emergency department in a tertiary-care hospital in Sichuan, China. During four waves of assessments at 1 week, 3, 6 and 12 months, mental fatigue was assessed through Mental Fatigue Scale (MFS) whereas social support was assessed by the Multidimensional Scale of Perceived Social Support (MSPSS).

RESULTS

There were 65.1%, 37.1%, 34.8% and 32.5% individuals being identified as those with mental fatigue at 1 week, 3, 6 and 12 months, respectively. The scores of MFS didn't change substantially since 3 months post-injury. Compared to non-fatigued MTBI patients, those with long-lasting post- MTBI fatigue reported extremely lower level of perceived social support. Moreover, improved social support at 1 week was negatively associated with the occurrence of long-lasting fatigue.

CONCLUSION

Sufficient social support could significantly decrease the occurrence of long-lasting mental fatigue among MTBI cases. It seemed of great importance to modify the emphasis of rehabilitation to include assessment and improvement of perceived social support at earlier stages after injury.