Predictors of cognitive and physical fatigue in post-acute mild-moderate traumatic brain injury

Stressful life events are associated with self-reported fatigue and depressive symptoms in patients with mild traumatic brain injury

OBJECTIVE

To examine the associations between recent stressful life events and self-reported fatigue and depressive symptoms in patients with mild traumatic brain injury.

DESIGN

Observational cohort study.

PARTICIPANTS

Patients (aged 18-68 years) with mild traumatic brain injury (n = 99) or lower extremity orthopaedic injury (n = 34).

METHODS

Data on stressful life events and self-reported symptoms were collected 3 months post-injury. Stressful life events in the last 12 months were assessed as part of a structured interview using a checklist of 11 common life events, self-reported fatigue with Barrow Neurological Institute Fatigue Scale, and depressive symptoms with Beck Depression Inventory - Fast Screen.

RESULTS

Median number of stressful life events was 1 (range 0-7) in the mild traumatic brain injury group and 1.5 (range 0-6) in the orthopaedic injury group. The groups did not differ significantly in terms of fatigue or depressive symptoms. In the mild traumatic brain injury group, the total number of recent stressful life events correlated significantly with self-reported fatigue (rs = 0.270, p = 0.007) and depressive symptoms (rs = 0.271, p = 0.007).

CONCLUSION

Stressful life events are associated with self-reported fatigue and depressive symptoms in patients with mild traumatic brain injury. Clinicians should consider stressful life events when managing patients who experience these symptoms, as this may help identifying potential targets for intervention.

Diet's Impact on Post-Traumatic Brain Injury Depression: Exploring Neurodegeneration, Chronic Blood-Brain Barrier Destruction, and Glutamate Neurotoxicity Mechanisms

Traumatic brain injury (TBI) has a profound impact on cognitive and mental functioning, leading to lifelong impairment and significantly diminishing the quality of life for affected individuals. A healthy blood-brain barrier (BBB) plays a crucial role in guarding the brain against elevated levels of blood glutamate, making its permeability a vital aspect of glutamate regulation within the brain. Studies have shown the efficacy of reducing excess glutamate in the brain as a treatment for post-TBI depression, anxiety, and aggression. The purpose of this article is to evaluate the involvement of dietary glutamate in the development of depression after TBI. We performed a literature search to examine the effects of diets abundant in glutamate, which are common in Asian populations, when compared to diets low in glutamate, which are prevalent in Europe and America. We specifically explored these effects in the context of chronic BBB damage after TBI, which may initiate neurodegeneration and subsequently have an impact on depression through the mechanism of chronic glutamate neurotoxicity. A glutamate-rich diet leads to increased blood glutamate levels when contrasted with a glutamate-poor diet. Within the context of chronic BBB disruption, elevated blood glutamate levels translate to heightened brain glutamate concentrations, thereby intensifying neurodegeneration due to glutamate neurotoxicity.

Self-reported Fatigue was Associated with Increased White-matter Alterations in Long-term Traumatic Brain Injury and Posttraumatic Stress Disorder Patients

Fatigue is a long-lasting problem in traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD), with limited research that investigated the fatigue-related white-matter changes within TBI and/or PTSD cohorts. This exploratory cross-sectional study used diffusion tensor imaging (DTI) and neuropsychological data collected from 153 male Vietnam War veterans, as part of the Alzheimer's Disease Neuroimaging Initiative - Department of Defense, and were divided clinically into control veterans, PTSD, TBI, and with both TBI and PTSD (TBI + PTSD). The existence of fatigue was defined by the question "Do you often feel tired, fatigued, or sleepy during the daytime?". DTI data were compared between fatigue and non-fatigue subgroups in each clinical group using tract-based spatial statistics voxel-based differences. Fatigue was reported in controls (29.55%), slightly higher in TBI (52.17%, PBenf = 0.06), and significantly higher in both TBI + PTSD (66.67%, PBenf = 0.001) and PTSD groups (79.25%, PBenf < 0.001). Compared to non-fatigued subgroups, no white-matter differences were observed in the fatigued subgroups of control or TBI, while the fatigued PTSD subgroup only showed increased diffusivity measures (i.e., radial and axial), and the fatigued TBI + PTSD subgroup showed decreased fractional anisotropy and increased diffusivity measures (PFWE ≤ 0.05). The results act as preliminary findings suggesting fatigue to be significantly reported in TBI + PTSD and PTSD decades post-trauma with a possible link to white-matter microstructural differences in both PTSD and TBI + PTSD. Future studies with larger cohorts and detailed fatigue assessments would be required to identify the white-matter changes associated with fatigue in these cohorts.

Sex predicts post-concussion symptom reporting, independently of fatigue and subjective sleep disturbance, in premorbidly healthy adults after mild traumatic brain injury

The relationship between sex and post-concussion symptom (PCS) reporting after mild traumatic brain injury (mTBI) is not well understood. Subjective sleep disturbance and fatigue impact PCS reporting after mTBI and show sex differences in the normal population. This study investigated whether sex had a relationship with PCS reporting after mTBI, independently of self-reported sleep disturbance and fatigue. Ninety-two premorbidly healthy adults in the post-acute period after mTBI completed the Rivermead Post-Concussion Symptoms Questionnaire, the Pittsburgh Sleep Quality Index, the Multidimensional Fatigue Inventory and measures of depression, anxiety and post-traumatic stress symptomatology. Females (n = 23) demonstrated higher levels of fatigue (p = .019) and greater psychological distress (p = .001) than males (n = 69), but equivalent levels of sleep disturbance (p = .946). Bootstrapping analyses were undertaken because PCS responses were not normally distributed. Female sex predicted greater PCS reporting (p = .001), independently of subjective sleep disturbance, fatigue, psychological distress and litigation status. The current findings support and extend previous work showing premorbidly healthy females are at higher risk of experiencing elevated PCS after mTBI than males in the post-acute period after mTBI. It may be beneficial for clinicians to be particularly sensitive to increased symptom reporting after mTBI in females, irrespective of sleep quality, fatigue or psychological status.

Prevalence of suicidal ideation and suicide attempt among patients with traumatic brain injury: A meta-analysis

BACKGROUND

Suicidality is common among patients with traumatic brain injury (TBI). This meta-analysis aimed to assess the prevalence of suicidal ideation (SI) and suicide attempt (SA) in TBI patients.

METHODS

Databases including PubMed, Cochrane Library, Embase, CINAHL, Web of Science, PsycINFO, China National Knowledge Infrastructure (CNKI), VIP, WanFang Data, and Chinese Biomedical Literature Database (CBM) were searched for relevant literature from inception to 9th January 2021. Random effects models were used to estimate the prevalence of SI and SA. The methodological quality of the included studies was assessed using the modified Newcastle-Ottawa Scale. Subgroup analysis was performed based on the geographical location of the institutions.

RESULTS

A total of 16 studies involving 1,146,271 patients with TBI were included in our meta-analysis. The prevalence of SI and SA were 19.1% (95% CI 13.6-24.6%) and 2.1% (95% CI 1.8-2.4%), respectively, while the prevalence of SA in Asian and non-Asian countries were 2.0% (95% CI 0.3-3.7%) and 2.0% (95% CI 1.6-2.3%). Meta-regression analyses revealed that the publication year and age were positively associated, while the geographical location of the institution and sample size were negatively associated with the pooled prevalence of SI. On the other hand, the geographical location of the institution, sample size and age were negatively associated with the pooled prevalence of SA.

LIMITATIONS

The overall heterogeneity between studies was high.

CONCLUSION

SI and SA are common among TBI patients. Therefore, targeted preventive measures are paramount to manage TBI-related suicide.

Greater Severity and Functional Impact of Post-traumatic Headache in Veterans With Comorbid Neck Pain Following Traumatic Brain Injury

BACKGROUND

Post-traumatic headache (PTH) is a commonly experienced symptom after mild traumatic brain injury (mTBI). Blast injury- or blunt injury-related mechanisms for mTBI in veterans can also affect musculoskeletal structures in the neck, resulting in comorbid neck pain (NP). However, it is unknown whether the presence of comorbid NP may be associated with a different pattern of headache symptoms, physical functioning, or emotional functioning compared to those without comorbid NP. The purpose of this study is to examine the role of comorbid NP in veterans with mTBI and PTH.

DESIGN AND METHODS

This was a cross-sectional investigation of an existing dataset that included 33 veterans who met inclusion criteria for PTH after mTBI. Standardized measures of headache severity and frequency, insomnia, fatigue, mood disorders, and physical and emotional role function were compared between groups with and without comorbid NP.

RESULTS

The majority of participants with PTH reported comorbid NP (n = 22/33, 67%). Those with comorbid NP experienced more headache symptoms that were severe or incapacitating, as compared to mild or moderate for those without NP (φ = 0.343, P = .049); however, no differences in headache frequency (φ = 0.231, P = .231) or duration (φ = 0.129, P = .712) were observed. Participants with comorbid NP also reported greater insomnia (d = 1.16, P = .003) and fatigue (d = 0.868, P = .040) as well as lower physical functioning (d = 0.802, P = .036) and greater bodily pain (d = 0.762, P = .012). There were no differences in anxiety, depression, mental health, emotional role limitations, vitality, or social functioning between those with and without comorbid NP (d ≤ 0.656, P ≥ .079).

CONCLUSIONS

A majority of veterans with mTBI and PTH in our sample reported comorbid NP that was associated with greater headache symptom severity and physical limitations, but not with mood or emotional limitations. Preliminary findings from this small convenience sample indicate that routine assessment of comorbid NP and associated physical limitations should be considered in veterans with mTBI and PTH.

Frequency of fatigue and its changes in the first 6 months after traumatic brain injury: results from the CENTER-TBI study

Background

Fatigue is one of the most commonly reported subjective symptoms following traumatic brain injury (TBI). The aims were to assess frequency of fatigue over the first 6 months after TBI, and examine whether fatigue changes could be predicted by demographic characteristics, injury severity and comorbidities.

Methods

Patients with acute TBI admitted to 65 trauma centers were enrolled in the study Collaborative European NeuroTrauma Effectiveness Research in TBI (CENTER-TBI). Subjective fatigue was measured by single item on the Rivermead Post-Concussion Symptoms Questionnaire (RPQ), administered at baseline, three and 6 months postinjury. Patients were categorized by clinical care pathway: admitted to an emergency room (ER), a ward (ADM) or an intensive care unit (ICU). Injury severity, preinjury somatic- and psychiatric conditions, depressive and sleep problems were registered at baseline. For prediction of fatigue changes, descriptive statistics and mixed effect logistic regression analysis are reported.

Results

Fatigue was experienced by 47% of patients at baseline, 48% at 3 months and 46% at 6 months. Patients admitted to ICU had a higher probability of experiencing fatigue than those in ER and ADM strata. Females and individuals with lower age, higher education, more severe intracranial injury, preinjury somatic and psychiatric conditions, sleep disturbance and feeling depressed postinjury had a higher probability of fatigue.

Conclusion

A high and stable frequency of fatigue was found during the first 6 months after TBI. Specific socio-demographic factors, comorbidities and injury severity characteristics were predictors of fatigue in this study.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-10022-2) contains supplementary material, which is available to authorized users.

An observational study of the association between sleep disturbance, fatigue and cognition in the post-acute period after mild traumatic brain injury in prospectively studied premorbidly healthy adults

The literature examining the relationship between sleep disturbance, fatigue, and cognition in premorbidly healthy civilian adults after mTBI is very limited. The current study aimed to investigate the relationships of sleep disturbance and fatigue with cognition while controlling for psychological distress and age. Using a prospective observational design, we assessed 60 premorbidly healthy individuals approximately 8 weeks after mTBI. Participants were assessed with the Pittsburgh Sleep Quality Index and the Multidimensional Fatigue Inventory as well as measures of speed of information processing, attention, memory, and executive function; depression and anxiety were also assessed. Findings revealed associations between sleep disturbance and cognition (r²= .586, p < .001) as well as between fatigue and cognition (r²= .390, p < .01), independent of the impact of psychological status and age. Associations were evident in the domains of processing speed, attention, and memory, but were most consistently apparent on measures of executive function. Greater sleep disturbance was most consistently associated with poorer cognitive function. Unexpectedly, higher levels of fatigue were associated with better cognitive function, which may be explained by the coping hypothesis. Given sleep interventions have been shown to improve sleep disturbance, these findings suggest that sleep intervention may also result in improved cognition after mTBI.

Characterizing the Risk of Depression Following Mild Traumatic Brain Injury: A Meta-Analysis of the Literature Comparing Chronic mTBI to Non-mTBI Populations

Objective: Mild traumatic brain injury (mTBI) is associated with depressed mood acutely post-injury, but there is little evidence regarding long-term depression. The aim of this study was to determine the odds ratio (OR) of depression chronically following mTBI.

Methods: We searched Medline (PubMed), ProQuest, and Web of Science from date of database creation to January 23, 2019, for eligible studies examining depression at least 6 months post-injury in adult subjects with mTBI of any etiology, including civilians and military. Three authors independently reviewed titles and abstracts for study eligibility. Data were extracted and collated by two investigators. Risk of bias was assessed with the SIGN methodology. Study data were pooled using random-effects meta-analysis. The primary exposure was mTBI, and the primary outcome was depression. Secondary exploratory variables were time of assessment, age at injury, age at assessment, sex, and etiology.

Results: We included 47 cross-sectional studies (n = 25,103 mTBI and 29,982 control), 26 cohort studies (n = 70,119 mTBI, 262,034 control), four prospective observational studies (n = 1,058 mTBI and 733 control), two prospective longitudinal studies (n = 119 mTBI, 81 control), two case-control studies (n = 56 mTBI, 56 control), and one randomized controlled trial (n = 252 mTBI, 3,214 control). mTBI was associated with a 3.29-fold increased risk of depression (OR 3.29, 95% CI 2.68–4.03, I² = 96%). The OR for depression did not change when subjects were assessed at 6–12 months (OR 2.43, 1.45–4.07), years 1–2 (OR 4.12, 2.10–8.07); 2–10 (OR 3.28, 2.42–4.46), or 10+ (OR 3.42, 1.51–7.77). Similar risk of depression was sustained across different age at injury (<25: OR 2.26, 1.82–2.81; 25–35: OR 4.67, 3.06–7.14; >35: OR 2.69, 1.42–5.10) and different age at assessment (<40 years: OR 3.14, 2.48–3.99; >40 years: OR 4.57, 2.54–8.24). Female sex had a non-significant increase in OR (OR 19.97, 2.39–166.93) compared to male (OR 3.0, 2.33–3.86). mTBI etiology had no impact on depression.

Conclusions: Those experiencing mTBI are more than three times more likely to experience depression compared to those without a history of mTBI, and this risk remains decades beyond the mTBI event. Future longitudinal studies are needed to identify and mitigate this risk.

The Relation Between Loss of Consciousness, Severity of Traumatic Brain Injury, and Injury of Ascending Reticular Activating System in Patients With Traumatic Brain Injury

OBJECTIVE

Loss of consciousness is an indicator of the severity of traumatic brain injury and the ascending reticular activating system has been considered as a main structure for consciousness. However, no study on the relation between loss of consciousness and ascending reticular activating system injury in traumatic brain injury has been reported. We investigated the relation between loss of consciousness, severity of traumatic brain injury, and ascending reticular activating system injury using diffusion tensor tractography.

DESIGN

One hundred twenty patients were recruited. Three components of ascending reticular activating system, fractional anisotropy, and tract volume were measured.

RESULTS

In lower dorsal and ventral ascending reticular activating system, fractional anisotropy and tract volume value in mild group were higher than those of moderate and severe groups, and there was no difference between moderate and severe groups. In upper ascending reticular activating system, fractional anisotropy value in mild group was higher than in moderate group, and it was higher than in moderate group than in severe group. Tract volume value in mild group was higher than in severe group. Loss of consciousness showed moderate negative correlations with tract volume value of lower dorsal ascending reticular activating system (r = -0.348), fractional anisotropy value of lower ventral ascending reticular activating system (r = -0.343), and fractional anisotropy value of upper ascending reticular activating system (r = -0.416).

CONCLUSIONS

Injury severity was different among the three traumatic brain injury groups in upper ascending reticular activating system but did not differ between moderate and severe groups in lower dorsal and ventral ascending reticular activating system.

Traumatic brain injury and sleep disturbances in combat-exposed service members and veterans: Where to go next?

OBJECTIVE

To synthesize the current evidence on sleep disturbances in military service members (SMs) and veterans with traumatic brain injury (TBI).

METHODS

An electronic literature search first identified abstracts published from 2008-2018 inclusively referencing sleep, TBI, and military personnel from Operation Enduring Freedom, Operation Iraqi Freedom, Operation New Dawn, and Persian Gulf veterans. Selection criteria eliminated studies on non-combat TBI, open or penetrating injuries, and articles where the relationship between sleep and TBI was not directly examined. Articles on all military branches and components, those currently serving and veterans-ranging from medical chart reviews to clinical trials, were included. Forty-one articles were selected for full text-review.

RESULTS

Twenty-four papers estimated the prevalence of sleep disturbances in TBI. Eight studies demonstrated the contribution of common co-occurring conditions, most notably posttraumatic stress disorder, to the relationship between disrupted sleep and TBI. Ten studies differentiated sleep profiles between military SMs and veterans with and without acute TBI and detected significant differences in sleep disturbances across the course of injury. Longitudinal studies were scarce but helped to establish the temporal relationship between sleep disturbances and TBI and isolate sleep-related mechanisms influencing TBI prognosis. Only three studies reported on interventions for improving sleep quality and TBI symptoms. Systematic research testing assessments and interventions that target sleep disturbances for improving sleep, TBI symptoms, and long-term functional outcomes were identified as critical knowledge gaps.

CONCLUSION

Findings unequivocally establish that sleep disturbances are highly prevalent in SMs and veterans with TBI. However, studies testing the effectiveness of treatments for improving sleep in military groups with TBI have been limited and their results inconsistent. This review highlights a critical opportunity for advancing military medicine through future research aimed at identifying and testing sleep-focused treatments in SMs and veterans with combat-related TBI.

Increasing Risks of Suicide Attempt and Suicidal Drug Overdose After Head Trauma in Patients With Sleep-Disordered Breathing: A Population-Based Study

Objective: To determine the risks of suicide attempt (SA) and suicidal drug overdose (SDO) after head trauma in patients with sleep-disordered breathing (SDB) by using the National Health Insurance Research Database of Taiwan. Methods: We analyzed the data of patients aged ≥20 years who were diagnosed with SDB between 2000 and 2012. We further divided them into two cohorts [with admission for head injury (SBI) and without (SBN)], and we compared them against sex-, age-, comorbidity-, and index-date-matched healthy individuals. The adjusted hazard ratios (aHRs) and 95% confidence intervals of SA and SDO were calculated with adjustment of age, sex, and comorbidities. Results: Approximately 0.61% of patients among the overall 142,063 patients with SDB had SA, with 535 and 335 patients included in the SBN and SBI cohorts, respectively. Compared with patients with SBN, a significantly higher risk of SA was observed in patients with SBI (aHR = 2.22), especially in those aged under 50 years (aHR = 2.48). Notably, a SDO incidence of 1.20% was noted in patients with SDB, and the SBI cohort had a 1.81-fold higher risk for SDO when compared with the SBN cohort. Conclusion: The risks of subsequent SA and SDO are proportionally increased by the effects of head trauma with a moderating role of SDB, especially in those aged <50 years. SDB and head trauma can increase suicide behaviors individually and synergistically.

Fatigue Is Associated With Global and Regional Thalamic Morphometry in Veterans With a History of Mild Traumatic Brain Injury

OBJECTIVE

Fatigue is a complex, multidimensional phenomenon that commonly occurs following traumatic brain injury (TBI). The thalamus-a structure vulnerable to both primary and secondary injuries in TBI-is thought to play a pivotal role in the manifestation of fatigue. We explored how neuroimaging markers of local and global thalamic morphometry relate to the subjective experience of fatigue post-TBI.

METHODS

Sixty-three Veterans with a history of mild TBI underwent structural magnetic resonance imaging and completed questionnaires related to fatigue and psychiatric symptoms. FMRIB's Software (FSL) was utilized to obtain whole brain and thalamic volume estimates, as well as to perform regional thalamic morphometry analyses.

RESULTS

Independent of age, sex, intracranial volume, posttraumatic stress disorder, and depressive symptoms, greater levels of self-reported fatigue were significantly associated with decreased right (P = .026) and left (P = .046) thalamic volumes. Regional morphometry analyses revealed that fatigue was significantly associated with reductions in the anterior and dorsomedial aspects of the right thalamic body (P < .05). Similar trends were observed for the left thalamic body (P < .10).

CONCLUSIONS

Both global and regional thalamic morphometric changes are associated with the subjective experience of fatigue in Veterans with a history of mild TBI. These findings support a theory in which disruption of thalamocorticostriatal circuitry may result in the manifestation of fatigue in individuals with a history of neurotrauma.

An observational study of trait and state fatigue, and their relation to cognitive fatigability and saccade performance

Aim:

Different fatigue measurements and their relation to saccadic functions were investigated in 15 patients with a mild traumatic brain injury (mTBI) and 15 orthopedic controls.

Materials & methods:

State fatigue was measured with the Fatigue Severity Scale and trait fatigue with the question on fatigue in the Rivermead Post Concussion Questionnaire and fatigability as decreased performance over time on a neuropsychological measure.

Results:

Patients with an mTBI scored significantly higher in state fatigue and showed more fatigability compared with the orthopedic controls. Among patients with mTBI, state fatigue correlated with prosaccade latency and cognitive fatigability, while trait fatigue correlated with anxiety and antisaccade latency and variability.

Conclusion:

This pilot study indicates that saccade measurements might, in the future, be useful in the understanding of fatigue and in the search for prognostic factors after mTBI.

Increased Risks of Suicide Attempt and Suicidal Drug Overdose Following Admission for Head Injury in Patients with Depression

Aims: To determine the risks of suicide attempt (SA) and suicidal drug overdose (SDO) following the admission for head injury of patients with depression. Design: We analyzed the NHIRD data of patients aged ≥20 years who had received depression diagnoses between 2000 and 2010. They were divided into cohorts of those with admission for head injury (DHI) and those without it (DWI) during the follow-up period and compared against a sex-, age-, comorbidity-, and index-date-matched cohort from the general population. Setting: The Taiwan National Health Insurance Research Database (NHIRD). Participants/Cases: We analyzed the NHIRD data of patients (≥20 years) who had received depression diagnoses between 2000 and 2010. Intervention(s): Regular interventions. Measurements: We calculated the adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) of SA and SDO in these cohorts after adjustment for age, sex, and comorbidities. Findings: Up to the end of 2011, our results revealed extremely high incidences of SA and SDO with 63.3 and 88.6 per 10,000 person-years, respectively, in the DHI cohort. The DHI cohort had a 37.4-times higher risk for SA and a 17.1-times higher risk for SDO compared with the comparison group and had aHRs of 14.4 and 16.3, respectively, for poisoning by medicinal substances and poisoning by tranquilizers compared with patients in the DWI cohort. Patients with DHI aged <50 years, of female sex, with high incomes, living in more urbanized areas, and without other comorbidities had extraordinarily higher risks for SA. Conclusions: The risks of SA and SDO were proportionally increased by head injury in patients with depression in Taiwan. Our findings provide crucial information to implement efficient suicide prevention strategies in the future.

Physiological and pathological covariates of persistent concussion-related fatigue: results from two regression methodologies

BACKGROUND

Fatigue severity in persons with mild traumatic brain injury (mTBI) has received little research attention, despite its typically positively skewed nature. Investigation of covariates across a range of fatigue severity may provide insight into important contributors.

OBJECTIVE

To assess the relative significance of a priori-hypothesized covariates of physiological and pathological (mental and physical) fatigue in persons with mTBI/concussion, applying ordinary least squares (OLS) and quantile regression (QR) approaches.

METHODS

We conducted a cross-sectional investigation in 80 participants with mTBI/concussion (mean age 45.4 ± 10.1 years, 59% male). The fatigue severity scale (FSS) was used as an outcome measure. Predictors of this outcome, grouped into physiological and pathological models of fatigue were assessed using OLS and QR.

RESULTS

The mean total FSS score was 46.13 ± 14.59, and the median was 49 (interquartile range 37-57), demonstrating positive skewness. Fatigue severity was associated with variables within the mental, psychological and psychiatric domains at different levels of the fatigue score distribution.

CONCLUSION

Results highlighted that some covariates had a significant impact on the FSS total score at non-central parts of its distribution, while others exhibited significant impact across the entire distribution. Addressing covariates of fatigue across the severity continuum can enhance research and clinical management.

Neuropsychological correlates of self-reported impulsivity and informant-reported maladaptive behaviour among veterans with posttraumatic stress disorder and traumatic brain injury history

OBJECTIVE

Frontal lobe deficits resulting from traumatic brain injury (TBI) and/or posttraumatic stress disorder (PTSD) have been linked to impulsive behaviour. We sought to examine whether neuropsychological performance predicted self-reported impulsivity and informant-reported maladaptive behaviour.

METHOD

We administered the Delis-Kaplan Executive Function System (D-KEFS) to 116 Iraq/Afghanistan-era veterans diagnosed with a history of TBI and PTSD.

RESULTS

Poorer performance on D-KEFS Stroop Task (both colour and word, separately) and Trail making (letter sequencing and motor speed) tasks and higher PTSD symptom severity were associated with higher self-reported impulsivity. Trail making letter sequencing performance was negatively associated with informant-reported maladaptive behaviour. Regression analyses revealed PTSD symptom severity and Trail making letter sequencing best predicted self-reported impulsivity, even when accounting for age, sex, and education. Only Trail making letter sequencing predicted informant-reported maladaptive behaviour when accounting for other variables in the model.

CONCLUSIONS

Attention and processing speed impairments and PTSD symptom severity appear to be important predictors of impulsivity and problematic behaviour among veterans. Findings have implications for theoretical models of aggression and violence and inform the assessment and treatment of individuals with TBI and PTSD.

Cognitive fatigue is associated with reduced anterior internal capsule integrity in veterans with history of mild to moderate traumatic brain injury

No known studies have directly examined white matter microstructural correlates of cognitive fatigue post-TBI in a Veteran sample. We therefore investigated the relationship between cognitive fatigue and white matter integrity in Veterans with history of mild to moderate TBI (mmTBI). 59 Veterans (TBI = 34, Veteran Controls [VCs] = 25]) with and without history of mmTBI underwent structural 3T DTI scans and completed questionnaires related to cognitive fatigue and psychiatric symptoms. Tractography was employed on six regions of interest, including the anterior and posterior limbs of the internal capsule; genu; body and splenium of the corpus callosum; and cingulum bundle. Group analyses revealed that those with history of mmTBI displayed significantly greater levels of cognitive fatigue relative to those with no history of head injury (p = .02). Within the mmTBI group, independent of psychiatric symptoms, decreased white matter microstructural integrity of the left anterior internal capsule was associated with greater levels of cognitive fatigue (p = .01). Results show that the subjective experience of cognitive fatigue following neurotrauma may be linked to the disruption of striato-thalamo-cortical tracts that are important in mediating arousal and higher-order cognitive processes. These findings build upon those from existing functional neuroimaging studies in those with history of TBI, providing further evidence for the neural basis of cognitive fatigue in head injured adults.

Understanding the interplay between mild traumatic brain injury and cognitive fatigue: models and treatments

Nearly 2 million traumatic brain injuries occur annually, most of which are mild (mTBI). One debilitating sequela of mTBI is cognitive fatigue: fatigue following cognitive work. Cognitive fatigue has proven difficult to quantify and study, but this is changing, allowing models to be proposed and tested. Here, we review evidence for four models of cognitive fatigue, and relate them to specific treatments following mTBI. The evidence supports two models: cognitive fatigue results from the increased work/effort required for the brain to process information after trauma-induced damage; and cognitive fatigue results from sleep disturbances. While there are no evidence-based treatments for fatigue after mTBI, some pharmacological and nonpharmacological treatments show promise for treating this debilitating problem. Future work may target the role of genetics, neuroinflammation and the microbiome and their role in complex cognitive responses such as fatigue.

Prevalence and severity of fatigue in adolescents and young adults with acquired brain injury: A nationwide study

Objective: To investigate the prevalence and severity of fatigue in adolescents and young adults with acquired brain injury (ABI) compared with healthy controls (HCs) and to examine associations between fatigue and gender, age and level of education. Methods: This cross-sectional study included 15-30 year old patients with ABI and a convenience sample of 15-30 year old HCs. All participants completed the 20-item Multidimensional Fatigue Inventory (MFI-20). Pathological fatigue was defined as "General Fatigue" ≥12. Adjusted mean differences between groups were calculated using multivariate analysis of covariance (MANCOVA). The adjusted prevalence proportion ratio (PPR_adj) of pathological fatigue was calculated using Poisson regression. Results: The patients (n = 334) had higher scores than the HCs (n = 168) on all MFI-20 subscales with adjusted mean differences ranging from 1.7 to 4.7 and a higher prevalence of pathological fatigue (73% versus 29%), PPR_adj 2.7 (95% confidence interval 2.1-3.5). Female patients experienced more fatigue than males on the "General Fatigue" and "Reduced Activity" subscales, while no gender differences were found in the HC group. Patients and HCs with elementary education had elevated scores on the "Reduced Activity" and "Mental Fatigue" subscales. Age was not associated with any of the subscale scores. Conclusion: Young patients with ABI had markedly higher prevalence and severity of fatigue than HCs. Age (15-30 years) was not associated with fatigue. No clear patterns of associations were evident with gender and level of education. Abbreviations: ABI: acquired brain injury; CI: confidence interval; GF: general fatigue; GOSE: Glasgow Outcome Scale Extended; HC: healthy control; MANCOVA: multivariate analysis of covariance; MF: mental fatigue; MFI-20: Multidimensional Fatigue Inventory-20; PF: physical fatigue; RA: reduced activity; RM: reduced motivation; TBI: traumatic brain injury.

Sleep-Wake Disturbances After Traumatic Brain Injury: Synthesis of Human and Animal Studies

Sleep-wake disturbances following traumatic brain injury (TBI) are increasingly recognized as a serious consequence following injury and as a barrier to recovery. Injury-induced sleep-wake disturbances can persist for years, often impairing quality of life. Recently, there has been a nearly exponential increase in the number of primary research articles published on the pathophysiology and mechanisms underlying sleep-wake disturbances after TBI, both in animal models and in humans, including in the pediatric population. In this review, we summarize over 200 articles on the topic, most of which were identified objectively using reproducible online search terms in PubMed. Although these studies differ in terms of methodology and detailed outcomes; overall, recent research describes a common phenotype of excessive daytime sleepiness, nighttime sleep fragmentation, insomnia, and electroencephalography spectral changes after TBI. Given the heterogeneity of the human disease phenotype, rigorous translation of animal models to the human condition is critical to our understanding of the mechanisms and of the temporal course of sleep-wake disturbances after injury. Arguably, this is most effectively accomplished when animal and human studies are performed by the same or collaborating research programs. Given the number of symptoms associated with TBI that are intimately related to, or directly stem from sleep dysfunction, sleep-wake disorders represent an important area in which mechanistic-based therapies may substantially impact recovery after TBI.