Impact of traumatic brain injury on sleep: an overview

Investigation of Mild Traumatic Brain Injury Home Cage Behavior: The Home Cage Assay Advantages

This study utilized the Noldus PhenoTyper Home Cage Monitoring system (HCM) to assess the behavioral and cognitive changes of experimental closed-head mild traumatic brain injury (mTBI). Seventy-nine adult male Institute of Cancer Research (ICR) mice were subjected to either a sham procedure or closed-head mTBI using the weight-drop model. Seven days post-injury, separate cohorts of mice underwent either a non-cognitive or a cognitive home cage assessment, a treadmill fatigue test, or the Open Field Test. mTBI significantly influenced habituation behavior and circadian wheel-running activity. Notably, mTBI mice exhibited an increased frequency of visits to the running wheel, but each visit was shorter than those of controls. No significant differences between the groups in discrimination or reversal learning performance were observed. However, during the reversal learning stage, mTBI mice performed similarly to their initial discrimination learning levels, suggesting an abnormally faster rate of reversal learning. Home cage monitoring is a valuable tool for studying the subtle effects of mTBI, complementing traditional assays. The automated evaluation of habituation to novel stimuli (e.g., novel environment) could serve as a potentially sensitive tool for assessing mTBI-associated behavioral deficits.

Traumatic Brain Injury and Posttraumatic Stress Disorder Are Associated with Physical Health Burden among Post-9/11 Women Veterans

Background: Little research focuses on physical health outcomes of traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD) among post-9/11 women veterans (WVs). This study examined lifetime TBI, current PTSD, and their associations with biomarkers of cardiometabolic health, sleep, pain, and functional disability among post-9/11 WVs. Methods: WVs (n = 90) from the Translational Research Center for TBI and Stress Disorders longitudinal cohort study were included in this study. Gold standard clinician administered interviews assessed lifetime TBI (Boston Assessment of TBI-Lifetime) and current PTSD symptoms (Clinician-Administered PTSD Scale-IV). Objective measures of health included waist-hip ratio (WHR) and fasted blood biomarker (high density lipoprotein [HDL], low density lipoprotein [LDL], blood glucose, triglycerides) levels. Self-reported surveys assessed sleep, pain, and functional disability. Results: Just under two-thirds (58.9%) of WVs experienced a lifetime TBI, and just over half (53.3%) of this sample had a current PTSD diagnosis at the time of testing. Lifetime TBI was significantly associated with higher WHR, triglycerides levels, and worse pain and sleep (ps = <0.01 to 0.02; ds = 0.01 to 1.12). Current PTSD was significantly associated with higher WHR, lower HDL, and worse pain and sleep (ps = <0.01 to 0.02; ds = 0.009 to 1.19). PTSD was significantly associated with lower total functioning and each of its subdomains (βs = -0.58 to 0.63; ps = <0.001 to 0.02). Lifetime TBI was significantly associated with total functioning, mobility, and life/work (βs = -0.20 to 0.30; ps = <0.01 to 0.02). Conclusions: These findings highlight the importance of screening for lifetime TBI and cardiovascular disease for WVs and support transdiagnostic treatment approaches targeting physical health outcomes.

Sleep Disturbance During Post-Traumatic Amnesia and Early Recovery After Traumatic Brain Injury

After moderate to severe traumatic brain injury (TBI), sleep disturbance commonly emerges during the confused post-traumatic amnesia (PTA) recovery stage. However, the evaluation of early sleep disturbance during PTA, its recovery trajectory, and influencing factors is limited. This study aimed to evaluate sleep outcomes in patients experiencing PTA using ambulatory gold-standard polysomnography (PSG) overnight and salivary endogenous melatonin (a hormone that influences the sleep-wake cycle) assessment at two time-points. The relationships between PSG-derived sleep-wake parameters and PTA symptoms (i.e., agitation and cognitive disturbance) were also evaluated. In a patient subset, PSG was repeated after PTA had resolved to assess the trajectory of sleep disturbance. Participants with PTA were recruited from Epworth HealthCare's inpatient TBI Rehabilitation Unit. Trained nurses administered overnight PSG at the patient bedside using the Compumedics Somté portable PSG device (Compumedics, Ltd., Australia). Two weeks after PTA had resolved, PSG was repeated. On a separate evening, two saliva specimens were collected (at 24:00 and 06:00) for melatonin testing. Results of routine daily hospital measures (i.e., Agitated Behavior Scale and Westmead PTA Scale) were also collected. Twenty-nine patients were monitored with PSG (mean: 41.6 days post-TBI; standard deviation [SD]: 28.3). Patients' mean sleep duration was reduced (5.6 h, SD: 1.2), and was fragmented with frequent awakenings (mean: 27.7, SD: 15.0). Deep, slow-wave restorative sleep was reduced, or completely absent (37.9% of patients). The use of PSG did not appear to exacerbate patient agitation or cognitive disturbance. Mean melatonin levels at both time-points were commonly outside of normal reference ranges. After PTA resolved, patients (n = 11) displayed significantly longer mean sleep time (5.3 h [PTA]; 6.5 h [out of PTA], difference between means: 1.2, p = 0.005). However, disturbances to other sleep-wake parameters (e.g., increased awakenings, wake time, and sleep latency) persisted after PTA resolved. This is the first study to evaluate sleep disturbance in a cohort of patients as they progressed through the early TBI recovery phases. There is a clear need for tailored assessment of sleep disturbance during PTA, which currently does not form part of routine hospital assessment, to suggest new treatment paradigms, enhance patient recovery, and reduce its long-term impacts.

The Frequency of Neuropsychiatric Sequelae After Traumatic Brain Injury in the Global South: A systematic review and meta-analysis

This study aimed to assess the prevalence of neuropsychiatric sequelae following traumatic brain injury (TBI) among the Western Asian, South Asian and African regions of the global south. All studies on psychiatric disturbances or cognitive impairment following TBI conducted (until August 2021) in the 83 countries that constitute the aforementioned regions were reviewed; 6 databases were selected for the literature search. After evaluating the articles using the Joanna Briggs Institute guidelines, the random effects model was used to estimate the prevalence of depression, anxiety, post-traumatic stress disorder (PTSD), TBI-related sleep disturbance (TBI-SD), obsessive-compulsive disorder (OCD) and cognitive impairment. Of 56 non-duplicated studies identified in the initial search, 27 were eligible for systematic review and 23 for meta-analysis. The pooled prevalence of depression in 1,882 samples was 35.35%, that of anxiety in 1,211 samples was 28.64%, that of PTSD in 426 samples was 19.94%, that of OCD in 313 samples was 19.48%, that of TBI-SD in 562 samples was 26.67% and that of cognitive impairment in 941 samples was 49.10%. To date, this is the first critical review to examine the spectrum of post-TBI neuropsychiatric sequelae in the specified regions. Although existing studies lack homogeneous data due to variability in the diagnostic tools and outcome measures utilised, the reported prevalence rates are significant and comparable to statistics from the global north.

Clinical Outcomes and Tau Pathology in Retired Football Players: Associations With Diagnosed and Witnessed Sleep Apnea

Background and Objectives

Obstructive sleep apnea (SA) is common in older men and a contributor to negative cognitive, psychiatric, and brain health outcomes. Little is known about SA in those who played contact sports and are at increased risk of neurodegenerative disease(s) and other neuropathologies associated with repetitive head impacts (RHI). In this study, we investigated the frequency of diagnosed and witnessed SA and its contribution to clinical symptoms and tau pathology using PET imaging among male former college and former professional American football players.

Methods

The sample included 120 former National Football League (NFL) players, 60 former college players, and 60 asymptomatic men without exposure to RHI (i.e., controls). Diagnosed SA was self-reported, and all participants completed the Mayo Sleep Questionnaire (MSQ, informant version), the Epworth Sleepiness Scale (ESS), neuropsychological testing, and tau (flortaucipir) PET imaging. Associations between sleep indices (diagnosed SA, MSQ items, and the ESS) and derived neuropsychological factor scores, self-reported depression (Beck Depression Inventory-II [BDI-II]), informant-reported neurobehavioral dysregulation (Behavior Rating Inventory of Executive Function-Adult Version [BRIEF-A] Behavioral Regulation Index [BRI]), and tau PET uptake, were tested.

Results

Approximately 36.7% of NFL players had diagnosed SA compared with 30% of the former college football players and 16.7% of the controls. Former NFL players and college football players also had higher ESS scores compared with the controls. Years of football play was not associated with any of the sleep metrics. Among the former NFL players, diagnosed SA was associated with worse Executive Function and Psychomotor Speed factor scores, greater BDI-II scores, and higher flortaucipir PET standard uptake value ratios, independent of age, race, body mass index, and APOE ε4 gene carrier status. Higher ESS scores correlated with higher BDI-II and BRIEF-A BRI scores. Continuous positive airway pressure use mitigated all of the abovementioned associations. Among the former college football players, witnessed apnea and higher ESS scores were associated with higher BRIEF-A BRI and BDI-II scores, respectively. No other associations were observed in this subgroup.

Discussion

Former elite American football players are at risk of SA. Our findings suggest that SA might contribute to cognitive, neuropsychiatric, and tau outcomes in this population. Like all neurodegenerative diseases, this study emphasizes the multifactorial contributions to negative brain health outcomes and the importance of sleep for optimal brain health.

Sleep, inflammation, and hemodynamics in rodent models of traumatic brain injury

Traumatic brain injury (TBI) can induce dysregulation of sleep. Sleep disturbances include hypersomnia and hyposomnia, sleep fragmentation, difficulty falling asleep, and altered electroencephalograms. TBI results in inflammation and altered hemodynamics, such as changes in blood brain barrier permeability and cerebral blood flow. Both inflammation and altered hemodynamics, which are known sleep regulators, contribute to sleep impairments post-TBI. TBIs are heterogenous in cause and biomechanics, which leads to different molecular and symptomatic outcomes. Animal models of TBI have been developed to model the heterogeneity of TBIs observed in the clinic. This review discusses the intricate relationship between sleep, inflammation, and hemodynamics in pre-clinical rodent models of TBI.

Traumatic Brain Injury-Induced Fear Generalization in Mice Involves Hippocampal Memory Trace Dysfunction and Is Alleviated by (R,S)-Ketamine

BACKGROUND

Traumatic brain injury (TBI) is a debilitating neurological disorder caused by an impact to the head by an outside force. TBI results in persistent cognitive impairments, including fear generalization and the inability to distinguish between aversive and neutral stimuli. The mechanisms underlying fear generalization have not been fully elucidated, and there are no targeted therapeutics to alleviate this symptom of TBI.

METHODS

To identify the neural ensembles mediating fear generalization, we utilized ArcCreERT2 × enhanced yellow fluorescent protein (EYFP) mice, which allow for activity-dependent labeling and quantification of memory traces. Mice were administered a sham surgery or the controlled cortical impact model of TBI. Mice were then administered a contextual fear discrimination paradigm and memory traces were quantified in numerous brain regions. In a separate group of mice, we tested if (R,S)-ketamine could decrease fear generalization and alter the corresponding memory traces in TBI mice.

RESULTS

TBI mice exhibited increased fear generalization when compared with sham mice. This behavioral phenotype was paralleled by altered memory traces in the dentate gyrus, CA3, and amygdala, but not by alterations in inflammation or sleep. In TBI mice, (R,S)-ketamine facilitated fear discrimination, and this behavioral improvement was reflected in dentate gyrus memory trace activity.

CONCLUSIONS

These data show that TBI induces fear generalization by altering fear memory traces and that this deficit can be improved with a single injection of (R,S)-ketamine. This work enhances our understanding of the neural basis of TBI-induced fear generalization and reveals potential therapeutic avenues for alleviating this symptom.

Sleep Disorders in Patients with Neurologic Disease

OBJECTIVE

This article provides an overview of the growing body of evidence showing bidirectional relationships between sleep and various neurologic disorders.

LATEST DEVELOPMENTS

Mounting evidence demonstrates that disrupted sleep can negatively impact various neurologic disease processes, including stroke, multiple sclerosis, epilepsy, neuromuscular disorders including amyotrophic lateral sclerosis, and headache syndromes. Abnormal sleep can also be a precursor to Alzheimer disease and neurodegenerative disease states such as Parkinson disease and dementia with Lewy bodies. Interventions to improve sleep and treat obstructive sleep apnea may play a vital role in preventing neurologic disease development and progression.

ESSENTIAL POINTS

Sleep disorders are common among patients with neurologic disorders. To provide comprehensive care to patients with neurologic conditions, neurologists must ask patients about sleep issues that may warrant further diagnostic testing, treatment, and sleep medicine referral when indicated.

The Correlation of Sleep Disturbance and Location of Glioma Tumors: A Narrative Review

Sleep disturbance can occur when sleep centers of the brain, regions that are responsible for coordinating and generating healthy amounts of sleep, are disrupted by glioma growth or surgical resection. Several disorders cause disruptions to the average duration, quality, or patterns of sleep, resulting in sleep disturbance. It is unknown whether specific sleep disorders can be reliably correlated with glioma growth, but there are sufficient numbers of case reports to suggest that a connection is possible. In this manuscript, these case reports and retrospective chart reviews are considered in the context of the current primary literature on sleep disturbance and glioma diagnosis to identify a new and useful connection which warrants further systematic and scientific examination in preclinical animal models. Confirmation of the relationship between disruption of the sleep centers in the brain and glioma location could have significant implications for diagnostics, treatment, monitoring of metastasis/recurrence, and end-of-life considerations.

Long-term Tractography Evaluation of Corpus Callosum Impairment After Severe Traumatic Brain Injury in Patients With Isolated Intraventricular Hemorrhage on Admission CT: Two Illustrative Cases and a Literature Review

Severe traumatic brain injury (TBI) is often associated with diffuse axonal injury. Diffuse axonal injury affecting the corpus callosum may present with intraventricular hemorrhage on baseline computed tomography (CT) scan. Posttraumatic corpus callosum damage is a chronic condition that can be diagnosed over the long term using various magnetic resonance imaging (MRI) sequences. Here, we present two cases of severe survivors of TBI with isolated intraventricular hemorrhage detected on an initial CT scan. After acute trauma management, long-term follow-up was performed. Diffusion tensor imaging and subsequent tractography revealed a significant decrease in the fractional anisotropy values and the number of corpus callosum fibers compared with those in healthy control patients. This study presents a possible correlation between traumatic intraventricular hemorrhage on admission CT and long-term corpus callosum impairment detected on MRI in patients with severe head injury by presenting demonstrative cases and conducting a literature review.

Acute Treatment with the M-Channel (Kv7, KCNQ) Opener Retigabine Reduces the Long-Term Effects of Repetitive Blast Traumatic Brain Injuries

We investigated whether pharmacological increase of "M-type" (KCNQ, Kv7) K + channel currents by the M-channel opener, retigabine (RTG), acutely after repetitive traumatic brain injuries (rTBIs), prevents or reduces their long-term detrimental effects. rTBIs were studied using a blast shock air wave mouse model. Animals were monitored by video and electroencephalogram (EEG) records for nine months after the last injury to assess the occurrence of post-traumatic seizures (PTS), post-traumatic epilepsy (PTE), sleep-wake cycle architecture alterations, and the power of the EEG signals. We evaluated the development of long-term changes in the brain associated with various neurodegenerative diseases in mice by examining transactive response DNA-binding protein 43 (TDP-43) expression and nerve fiber damage ~ 2 years after the rTBIs. We observed acute RTG treatment to reduce the duration of PTS and impair the development of PTE. Acute RTG treatment also prevented post-injury hypersomnia, nerve fiber damage, and cortical TDP-43 accumulation and translocation from the nucleus to the cytoplasm. Mice that developed PTE displayed impaired rapid eye movement (REM) sleep, and there were significant correlations between seizure duration and time spent in the different stages of the sleep-wake cycle. We observed acute RTG treatment to impair injury-induced reduction of age-related increase in gamma frequency power of the EGG, which has been suggested to be necessary for a healthy aged brain. The data show that RTG, administered acutely post-TBI, is a promising, novel therapeutic option to blunt/prevent several long-term effects of rTBIs. Furthermore, our results show a direct relationship between sleep architecture and PTE.

Toward explainable AI-empowered cognitive health assessment

Explainable artificial intelligence (XAI) is of paramount importance to various domains, including healthcare, fitness, skill assessment, and personal assistants, to understand and explain the decision-making process of the artificial intelligence (AI) model. Smart homes embedded with smart devices and sensors enabled many context-aware applications to recognize physical activities. This study presents XAI-HAR, a novel XAI-empowered human activity recognition (HAR) approach based on key features identified from the data collected from sensors located at different places in a smart home. XAI-HAR identifies a set of new features (i.e., the total number of sensors used in a specific activity), as physical key features selection (PKFS) based on weighting criteria. Next, it presents statistical key features selection (SKFS) (i.e., mean, standard deviation) to handle the outliers and higher class variance. The proposed XAI-HAR is evaluated using machine learning models, namely, random forest (RF), K-nearest neighbor (KNN), support vector machine (SVM), decision tree (DT), naive Bayes (NB) and deep learning models such as deep neural network (DNN), convolution neural network (CNN), and CNN-based long short-term memory (CNN-LSTM). Experiments demonstrate the superior performance of XAI-HAR using RF classifier over all other machine learning and deep learning models. For explainability, XAI-HAR uses Local Interpretable Model Agnostic (LIME) with an RF classifier. XAI-HAR achieves 0.96% of F-score for health and dementia classification and 0.95 and 0.97% for activity recognition of dementia and healthy individuals, respectively.

Traumatic brain injury-induced fear generalization in mice involves hippocampal memory trace dysfunction and is alleviated by ( R,S )-ketamine

INTRODUCTION

Traumatic brain injury (TBI) is a debilitating neurological disorder caused by an impact to the head by an outside force. TBI results in persistent cognitive impairments, including fear generalization, the inability to distinguish between aversive and neutral stimuli. The mechanisms underlying fear generalization have not been fully elucidated, and there are no targeted therapeutics to alleviate this symptom of TBI.

METHODS

To identify the neural ensembles mediating fear generalization, we utilized the ArcCreER T2 x enhanced yellow fluorescent protein (EYFP) mice, which allow for activity-dependent labeling and quantification of memory traces. Mice were administered a sham surgery or the controlled cortical impact (CCI) model of TBI. Mice were then administered a contextual fear discrimination (CFD) paradigm and memory traces were quantified in numerous brain regions. In a separate group of mice, we tested if ( R,S )-ketamine could decrease fear generalization and alter the corresponding memory traces in TBI mice.

RESULTS

TBI mice exhibited increased fear generalization when compared with sham mice. This behavioral phenotype was paralleled by altered memory traces in the DG, CA3, and amygdala, but not by alterations in inflammation or sleep. In TBI mice, ( R,S )-ketamine facilitated fear discrimination and this behavioral improvement was reflected in DG memory trace activity.

CONCLUSIONS

These data show that TBI induces fear generalization by altering fear memory traces, and that this deficit can be improved with a single injection of ( R,S )-ketamine. This work enhances our understanding of the neural basis of TBI-induced fear generalization and reveals potential therapeutic avenues for alleviating this symptom.

Dual orexin antagonist normalized sleep homeostatic drive, enhanced GABAergic inhibition, and suppressed seizures after traumatic brain injury

STUDY OBJECTIVES

Traumatic brain injury (TBI) can result in posttraumatic epilepsy (PTE) and sleep disturbances. We hypothesized that treatment with sleep aids after TBI can ameliorate PTE.

METHODS

CD-1 mice underwent controlled cortical impact (CCI), sham injury, or no craniotomy. Sham and CCI groups underwent a monthlong daily treatment with sleep aids including a dual orexin antagonist (DORA-22) or THIP (gaboxadol) or a respective vehicle starting on the day of CCI. We performed continuous EEG (electroencephalography) recordings at week 1 and months 1, 2, and 3 for ~1 week each time. Seizure analysis occurred at all-time points and sleep analysis occurred in week 1 and month-1/2 in all groups. Subsets of CCI and sham groups were subjected to voltageclamp experiments in hippocampal slices to evaluate GABAergic synaptic inhibition.

RESULTS

DORA-22 treatment suppressed seizures in month 1-3 recordings. TBI reduced the amplitude and frequency of miniature inhibitory synaptic currents (mIPSCs) in dentate granule cells and these changes were rescued by DORA-22 treatment. Sleep analysis showed that DORA-22 increased nonrapid eye movement (NREM) sleep during lights-off whereas THIP increased REM sleep during lights-on in week 1. Both treatments displayed subtle changes in time spent in NREM or REM at month-1/2 as well. TBI not only increased normalized EEG delta power (NΔ) at week-1 and month-1 but also resulted in the loss of the homeostatic diurnal oscillation of NΔ, which was restored by DORA-22 but not THIP treatment.

CONCLUSIONS

Dual orexin antagonists may have a therapeutic potential in suppressing PTE potentially by enhancing GABAergic inhibition and impacting sleep homeostatic drive.

Epigenetic Alterations in Sports-Related Injuries

It is a well-known fact that physical activity benefits people of all age groups. However, highly intensive training, maladaptation, improper equipment, and lack of sufficient rest lead to contusions and sports-related injuries. From the perspectives of sports professionals and those performing regular–amateur sports activities, it is important to maintain proper levels of training, without encountering frequent injuries. The bodily responses to physical stress and intensive physical activity are detected on many levels. Epigenetic modifications, including DNA methylation, histone protein methylation, acetylation, and miRNA expression occur in response to environmental changes and play fundamental roles in the regulation of cellular activities. In the current review, we summarise the available knowledge on epigenetic alterations present in tissues and organs (e.g., muscles, the brain, tendons, and bones) as a consequence of sports-related injuries. Epigenetic mechanism observations have the potential to become useful tools in sports medicine, as predictors of approaching pathophysiological alterations and injury biomarkers that have already taken place.

Association of Traumatic Brain Injury With and Without Loss of Consciousness With Neuropathologic Outcomes in Community-Dwelling Older Persons

Importance

A history of traumatic brain injury (TBI) has been considered a risk factor for Alzheimer dementia. However, the specific association of TBI, even without loss of consciousness (LOC), with pathologic findings that underlie Alzheimer dementia, including Alzheimer disease (AD), non-AD neurodegenerative, and vascular pathologic findings, remains unclear.

Objective

To examine the association between TBI with and without LOC and neuropathologic findings in community-based cohorts.

Design, Setting, and Participants

This cross-sectional analysis used neuropathologic data from 1689 participants from the Religious Orders Study, the Rush Memory and Aging Project, and the Minority Aging Research Study. These studies began enrollment in 1994, 1997, and 2004, respectively. The current study's data set was frozen on April 3, 2021, when the mean (SD) length of follow-up for the participants was 8.7 (5.5) years.

Exposure

Traumatic brain injury exposure was assessed using a standardized, self-reported questionnaire at baseline and annual follow-up visits. Participants were categorized into those (1) without TBI exposure (n = 1024), (2) with TBI with LOC (n = 161), or (3) with TBI without LOC (n = 504).

Main Outcomes and Measures

Neuropathologic measures of amyloid-β, paired helical filament tangles, neocortical Lewy bodies, transactive response DNA-binding protein 43, hippocampal sclerosis, gross infarcts, and microinfarcts were assessed. Multiple linear regression and logistic regression models were used to determine whether TBI with or without LOC (compared with no TBI exposure as the reference group) was associated with neuropathologic outcomes after adjusting for age at death, sex, and educational level. Whether the apolipoprotein E (APOE) ε4 allele and sex differences modified associations was also examined.

Results

A total of 1689 participants (1138 [67%] women and 551 [33%] men; mean [SD] age at death, 89.2 [6.7] years; 80 [5%] Black, 46 [3%] Latino, 1639 [97%] non-Latino, and 1601 [95%] White) participated in the study. Compared with participants without TBI, participants with TBI with LOC had a greater amyloid-β load (estimate, 0.25; 95% CI, 0.06-0.43; P = .008) and higher odds of having 1 or more gross infarcts (odds ratio [OR], 1.45; 95% CI, 1.04-2.02; P = .02) and 1 or more microinfarcts (OR, 1.70; 95% CI, 1.21-2.38; P = .002), particularly subcortical microinfarcts (OR, 1.85; 95% CI, 1.23-2.79; P = .002). Those with TBI without LOC had higher odds of neocortical Lewy bodies (OR, 1.37; 95% CI, 1.01-1.87; P = .04) and 1 or more cortical microinfarcts (OR, 1.43; 95% CI, 1.09-1.87; P = .008). The association of TBI with and without LOC with vascular pathologic outcomes persisted after controlling for vascular risk factors and vascular disease burden. Traumatic brain injury with or without LOC was not associated with paired helical filament tangles, transactive response DNA-binding protein 43, or hippocampal sclerosis. No interactions occurred with APOE ε4 or sex.

Conclusions and Relevance

This cross-sectional analysis suggests that a history of TBI, even without LOC, is associated with age-related neuropathologic outcomes, both neurodegenerative and vascular. The variation in the neuropathologic outcomes in individuals with and without LOC may provide clues to potential mechanisms, diagnoses, and management in persons with TBI.

A prospective controlled study on the impact of anterior temporal lobectomy on dream content

OBJECTIVE

Changes of dream ability and content in patients with brain lesions have been addressed in only about 100 case reports. All of these reports lack data regarding prelesional baseline dream content. Therefore, it was the objective of this study to prospectively assess dream content before and after anterior temporal lobectomy.

METHODS

Using the Hall and Van de Castle system, 30 dreams before and 21 dreams after anterior temporal lobectomy for drug-resistant epilepsy were analyzed. Fifty-five dreams before and 60 dreams after stereoelectroencephalography served as controls.

RESULTS

After anterior temporal lobectomy, patients had significantly less physical aggression in their dreams than preoperatively (p < 0.01, Cohen's h statistic). Dream content of patients undergoing stereoelectroencephalography showed no significant changes.

CONCLUSIONS

Within the default dream network, the temporal lobe may account for aggressive dream content. Impact of general anesthesia on dream content, as a possible confounder, was ruled out.

Multi-Scale Permutation Entropy: A Potential Measure for the Impact of Sleep Medication on Brain Dynamics of Patients with Insomnia

Insomnia is a common sleep disorder that is closely associated with the occurrence and deterioration of cardiovascular disease, depression and other diseases. The evaluation of pharmacological treatments for insomnia brings significant clinical implications. In this study, a total of 20 patients with mild insomnia and 75 healthy subjects as controls (HC) were included to explore alterations of electroencephalogram (EEG) complexity associated with insomnia and its pharmacological treatment by using multi-scale permutation entropy (MPE). All participants were recorded for two nights of polysomnography (PSG). The patients with mild insomnia received a placebo on the first night (Placebo) and temazepam on the second night (Temazepam), while the HCs had no sleep-related medication intake for either night. EEG recordings from each night were extracted and analyzed using MPE. The results showed that MPE decreased significantly from pre-lights-off to the period during sleep transition and then to the period after sleep onset, and also during the deepening of sleep stage in the HC group. Furthermore, results from the insomnia subjects showed that MPE values were significantly lower for the Temazepam night compared to MPE values for the Placebo night. Moreover, MPE values for the Temazepam night showed no correlation with age or gender. Our results indicated that EEG complexity, measured by MPE, may be utilized as an alternative approach to measure the impact of sleep medication on brain dynamics.

Sleep disturbance and length of stay in the setting of acquired brain injury rehabilitation

OBJECTIVE

The objective of this study was to investigate the impact and prevalence of sleep-wake disturbances among adult patients admitted for inpatient acquired brain injury rehabilitation.

METHOD

This was a retrospective cohort study involving all adults admitted for inpatient ABI neurocognitive rehabilitation at UHN-Toronto Rehabilitation Institute over a 12-month period (n = 165). The primary endpoint of the study was the comparison of functional independent measure efficiency and hospital length of stay between patients reporting sleep disturbance (e.g. increased sleep latency, obstructive sleep apnea [OSA], sleep maintenance insomnia) versus those with normal sleep.

RESULTS

We found that more than half (58.2%) of patients experienced sleep disturbance based on a combination of self-report and clinical documentation. The most common sleep disturbance was increased sleep onset latency (28.5%), followed by mixed sleep onset/maintenance insomnia (14.5%) and obstructive sleep apnea (8.5%). Notably, OSA was associated with longer length of hospital stay and reduced functional independence measure (FIM) efficiency in the cognitive domain after accounting for age and number of medical comorbidities.

IMPLICATIONS

The results of this investigation underscore the importance of screening patients with brain injury for sleep disturbances due to its high prevalence and impact on rehabilitation efficiency.

Sleep in Neurologic Disorders

Sleep is a complex brain state with fundamental relevance for cognitive functions, synaptic plasticity, brain resilience, and autonomic balance. Sleep pathologies may interfere with cerebral circuit organization, leading to negative consequences and favoring the development of neurologic disorders. Conversely, the latter can interfere with sleep functions. Accordingly, assessment of sleep quality is always recommended in the diagnosis of patients with neurologic disorders and during neurorehabilitation programs. This review investigates the complex interplay between sleep and brain pathologies, focusing on diseases in which the association with sleep disturbances is commonly overlooked and whereby major benefits may derive from their proper management.

Treatments for sleep disturbances in individuals with acquired brain injury: A systematic review

OBJECTIVE

To systematically review the evidence on the treatments of sleep disturbances in individuals with acquired brain injury.

DATA SOURCES

PubMed, Embase, Web of Science, and PsycINFO were searched from inception to January 2021.

REVIEW METHOD

Eligibility criteria were (1) participants with mild to severe acquired brain injury from traumatic brain injury and stroke (⩾three months post-injury), (2) individuals aged 16 years and older, (3) participants with self-reported sleep disturbances, (4) controlled group studies and single case (experimental) studies, and (5) interventions aimed at treatment of sleep disturbances. Two researchers independently identified relevant studies and assessed their study quality using the revised Cochrane assessment of bias tool (RoB 2.0) and the risk-of-bias in N-of-1 trials (RoBiNT) scale.

RESULTS

The search yielded 655 records; 11 studies met the inclusion criteria and were included, with a total of 227 participants (207 individuals with traumatic brain injury, 20 stroke patients). Two studies included pharmacological therapy, six studies examined the effects of cognitive behavioral therapy and three studies investigated alternative interventions such as acupuncture.

CONCLUSION

Although there was heterogeneity in the study quality of the included studies, their outcomes suggest that cognitive behavioral therapy is recommended as treatment of choice for improving sleep in individuals with acquired brain injury, especially for patients with mild to severe traumatic brain injury. Future research should examine the effects of cognitive behavioral therapy in more high-quality randomized controlled designs.

Sleep after Traumatic Brain Injury

Sleep disturbances are common after traumatic brain injury of all levels of severity, interfere with acute and long-term recovery, and can persist for years after injury. There is increasing evidence of the importance of sleep in improving brain function and recovery. Noticing and addressing sleep disturbances are important aspects of nursing care, especially for the prevention or early recognition of delirium. Nonpharmacologic interventions can improve sleep. Teaching about the importance of sleep after traumatic brain injury, promoting sleep hygiene, and multidisciplinary approaches to addressing sleep problems and improving sleep are important for recovery from traumatic brain injury.

Preliminary Validation of the Sleep and Concussion Questionnaire as an Outcome Measure for Sleep Following Brain Injury

BACKGROUND

Sleep and wakefulness disturbances are common with traumatic brain injury (TBI); however, there are no condition-specific measures to evaluate sleep following TBI.

OBJECTIVE

To assess the convergent validity of the Sleep and Concussion Questionnaire (SCQ), a condition-specific (TBI) measure is compared to polysomnography and existing self-report sleep questionnaires.

PARTICIPANTS INCLUDED

Thirty-two adults diagnosed with mild TBI, 3-24 months post-injury, average age, 38.9 years, predominantly female (63%) and with symptoms of chronic insomnia.

METHODS

Participants underwent polysomnographic evaluation of sleep and completed the SCQ, Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), and the Fatigue Severity Scale (FSS). Correlations were assessed using Pearson's correlations. The sample was sufficiently powered (0.85) to detect a moderate to strong correlation of 0.5 or greater.

RESULTS

SCQ sub-questions were meaningfully correlated with corresponding objective sleep parameters (time awake, number of awakenings, sleep efficiency, sleep onset latency, wake after sleep onset) as measured with polysomnography. Additional significant correlations were seen between total scores on the SCQ and ISI and between SCQ sub questions and total ESS scores.

CONCLUSIONS

This work provides initial evidence of the convergent validity of the SCQ with objective sleep parameters and existing self-report measures in patients after mild TBI.

Insomnia as a predictor of diagnosed memory problems: 2006-2016 Health and Retirement Study

OBJECTIVE

To evaluate the longitudinal relationship in insomnia symptoms over time with incident memory problems and dementia diagnoses among U.S. adults aged 65 years and older.

METHODS

Secondary analyses were performed on 9518 elderly participants (≥65 years) who completed the 2006 wave of the Health and Retirement Study (HRS) and were followed-up to determine if insomnia symptom scores (2006-2014) were associated with time-to-onset of [1] physician-diagnosed "memory-related disease", "Alzheimer's disease" and/or "dementia, senility or any other serious memory impairment" and [2] diagnosis of dementia based on HRS-specific criteria. Cox proportional hazards models were constructed adjusting for socio-demographic, lifestyle, and health characteristics.

RESULTS

In fully adjusted models, severe insomnia symptoms were associated with increased risk of physician-diagnosed memory problems. Individuals reporting any change (increase or decrease) in insomnia symptoms during the 2006-2010 period were more likely to be diagnosed with dementia based on HRS criteria. Finally, those who experienced an increase in the severity of insomnia symptoms over time exhibited 41-72% increased risks of physician-diagnosed memory problems and 45-58% increased risks of dementia diagnosis based on HRS criteria.

CONCLUSIONS

When severe insomnia symptoms increased over time, physician-diagnosed memory problems and dementia diagnoses also increased among U.S. elderly people over a 10-year follow-up period. More studies are required to confirm these findings using large prospective cohort designs and validated tools.

Part 2: Bypassing TBI-Metabolic Surgery and the Link Between Obesity and Traumatic Brain Injury-A Review

Obesity is a common outcome of traumatic brain injury (TBI) that exacerbates principal TBI symptom domains identified as common areas of post-TBI long-term dysfunction. Obesity is also associated with increased risk of later-life dementia and Alzheimer's disease. Patients with obesity and chronic TBI may be more vulnerable to long-term mental abnormalities. This review explores the question of whether weight loss induced by bariatric surgery could delay or perhaps even reverse the progression of mental deterioration. Bariatric surgery, with its induction of weight loss, remission of type 2 diabetes, and other expressions of the metabolic syndrome, improves metabolic efficiency, leads to reversal of brain lesions seen on imaging studies, and improves function. These observations suggest that metabolic/bariatric surgery may be the most effective therapy for TBI.

Sleep disorders and the hypothalamus

As early as the 1920s, pathological studies of encephalitis lethargica allowed Von Economo to correctly identify hypothalamic damage as crucial for the profound associated sleep-related symptoms that helped define the condition. Only over the last 3 decades, however, has the key role of the hypothalamus in sleep-wake regulation become increasingly recognized. As a consequence, a close relation between abnormal sleep symptomatology and hypothalamic pathology is now widely accepted for a variety of medical disorders. Narcolepsy is discussed in some detail as the cardinal primary sleep disorder that is caused directly and specifically by hypothalamic pathology, most notably destruction of hypocretin (orexin)-containing neurons. Thereafter, various conditions are described that most likely result from hypothalamic damage, in part at least, producing a clinical picture resembling (symptomatic) narcolepsy. Kleine-Levin syndrome is a rare primary sleep disorder with intermittent symptoms, highly suggestive of hypothalamic involvement but probably reflecting a wider pathophysiology. ROHHAD (rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation) and Prader-Willi syndrome are also covered as hypothalamic syndromes with prominent sleep-related symptoms. Finally, sleep issues in several endocrine disorders are briefly discussed.

Sleep disorders in traumatic brain injury

The purpose of the review is to collect the most relevant current literature on the mechanisms of normal sleep and sleep disorders associated with traumatic brain injury (TBI), to discuss the most frequent conditions and the evidence on their possible treatments and future research. Sleep disorders are extremely prevalent after TBI (30-84%). Insomnia and circadian rhythm disorders are the most frequent disorders among the population that has suffered mild TBI, while hypersomnolence disorders are more frequent in populations that have suffered moderate and severe TBI. The syndrome of obstructive sleep apnea and restless leg syndrome are also very frequent in these patients; and patients exposed to multiple TBIs (war veterans) are especially susceptible to sleep disorders. The treatment of these disorders requires taking into account the particularities of these patients. In conclusion, diagnosis and treatment of sleep disorders should become part of routine clinical practice and cease to be anecdotal (as it is today) in patients with TBI. In addition, it is necessary to continue carrying out research that reveals the best therapeutic approach to these patients.

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.

Sleep disorders in traumatic brain injury

The purpose of the review is to collect the most relevant current literature on the mechanisms of normal sleep and sleep disorders associated with traumatic brain injury (TBI), to discuss the most frequent conditions and the evidence on their possible treatments and future research. Sleep disorders are extremely prevalent after TBI (30-84%). Insomnia and circadian rhythm disorders are the most frequent disorders among the population that has suffered mild TBI, while hypersomnolence disorders are more frequent in populations that have suffered moderate and severe TBI. The syndrome of obstructive sleep apnea and restless leg syndrome are also very frequent in these patients; and patients exposed to multiple TBIs (war veterans) are especially susceptible to sleep disorders. The treatment of these disorders requires taking into account the particularities of these patients. In conclusion, diagnosis and treatment of sleep disorders should become part of routine clinical practice and cease to be anecdotal (as it is today) in patients with TBI. In addition, it is necessary to continue carrying out research that reveals the best therapeutic approach to these patients.

Bypassing TBI: Metabolic Surgery and the Link between Obesity and Traumatic Brain Injury-a Review

Obesity is a common outcome of traumatic brain injury (TBI) that exacerbates principal TBI symptom domains identified as common areas of post-TBI long-term dysfunction. Obesity is also associated with increased risk of later-life dementia and Alzheimer's disease. Patients with obesity and chronic TBI may be more vulnerable to long-term mental abnormalities. This review explores the question of whether weight loss induced by bariatric surgery could delay or perhaps even reverse the progression of mental deterioration. Bariatric surgery, with its induction of weight loss, remission of type 2 diabetes, and other expressions of the metabolic syndrome, improves metabolic efficiency, leads to reversal of brain lesions seen on imaging studies, and improves function. These observations suggest that metabolic/bariatric surgery may be a most effective therapy for TBI.