Actigraphically Measured Sleep-Wake Behavior After Mild Traumatic Brain Injury: A Case-Control Study.

OBJECTIVE: To characterize and compare the sleep-wake behavior of individuals following a mild traumatic brain injury (mTBI) with that of noninjured healthy controls. SETTING: Community. PARTICIPANTS: Fourteen participants with a recent mTBI (Mage = 28.07; SD = 10.45; n = 10 females) and 34 noninjured controls (Mage = 23.70; SD = 7.30; n = 31 females). DESIGN: Cross-sectional. MAIN MEASURES: Battery of subjective sleep measures and 14 days of sleep-wake monitoring via actigraphy (objective measurement) and concurrent daily sleep diary. RESULTS: Participants who had sustained an mTBI self-reported significantly higher sleep-related impairment, poorer nightly sleep quality, and more frequently met criteria for clinical insomnia, compared with controls (d = 0.76-1.11, large effects). The only significant between-group difference on objective sleep metrics occurred on sleep timing. On average, people with a recent history of mTBI fell asleep and woke approximately 1 hour earlier than did the controls (d = 0.62-0.92, medium to large effects). CONCLUSION: Participants with a history of mTBI had several subjective sleep complaints but relatively few objective sleep changes with the exception of earlier sleep timing. Future research is needed to understand the clinical significance of these findings and how these symptoms can be alleviated. Interventions addressing subjective sleep complaints (eg, cognitive behavior therapy for insomnia) should be tested in this population.

Poor sleep predicts subacute postconcussion symptoms following mild traumatic brain injury.

The primary objective was to determine if poor sleep predicts postconcussion symptoms in the subacute period after mild traumatic brain injury (TBI). The impact of poor sleep pre- and post-injury was examined. The research design was cross-sectional. After screening to detect response invalidity, 61 individuals with a self-reported history of mild TBI 1-to-6 months prior answered an online fixed order battery of standardized questionnaires assessing their sleep (current and preinjury) and persistent postconcussion symptoms (Neurobehavioral Symptom Inventory, minus sleep, and fatigue items). The sleep measures were the Insomnia Severity Index, Epworth Sleepiness Scale, a single Likert-scale pre-injury sleep quality rating, and two PROMIS™ measures (sleep-related impairment and sleep disturbance). After controlling for the effects of preinjury sleep quality and demographics, the combination of the sleep measures made a significant contribution to the outcome (F[8,58] = 4.013, p = .001, [Formula: see text]). Only current sleep-related impairment (ß = .60, p < .05) made a significant and unique contribution to neurobehavioral symptoms. Preinjury sleep was not a predictor (ß = -.19, p > .05), although it contributed 3% of the variance in NSI scores after controlling for demographics. Sleep-related impairment is a modifiable factor. As a significant contributor to neurobehavioral symptoms, treatment for post-injury sleep-related impairment warrants further attention.

Environmental Light Exposure Is Associated with Increased Body Mass in Children.

The timing, intensity, and duration of exposure to both artificial and natural light have acute metabolic and physiological effects in mammals. Recent research in human adults suggests exposure to moderate intensity light later in the day is concurrently associated with increased body mass; however, no studies have investigated the effect of light exposure on body mass in young children. We examined objectively measured light exposure and body mass of 48 preschool-aged children at baseline, and measured their body mass again 12 months later. At baseline, moderate intensity light exposure earlier in the day was associated with increased body mass index (BMI). Increased duration of light exposure at baseline predicted increased BMI 12-months later, even after controlling for baseline sleep duration, sleep timing, BMI, and activity. The findings identify that light exposure may be a contributor to the obesogenic environment during early childhood.

Toward the Multilevel Older Person's Transportation and Road Safety Model: A New Perspective on the Role of Demographic, Functional, and Psychosocial Factors.

OBJECTIVES: Self-regulation refers to the practice of using self-imposed restrictions to protect oneself from situations that are, or are perceived to be, unsafe. Within the driving context, self-regulation refers the compensatory practices that some older adults adopt to restrict their driving to situations in which they feel safe. However, the way in which demographic, functional, and psychosocial factors, and the interactions between these factors, influence older adults' driving self-regulation is not well understood. Improving this understanding could lead to new ways of considering the mobility concerns faced by older drivers. METHOD: A systematic review of the current literature was conducted to explore this issue. Twenty-nine empirical studies investigating the factors associated with older adults' self-regulatory driving behaviors were examined. RESULTS: The review findings were used to construct the Multilevel Older Persons Transportation and Road Safety (MOTRS) model. The MOTRS model proposes that individual and environmental factors such as age, gender, and the availability of alternative transportation predict older adults' practice of driving-related self-regulation. However, these variables influence self-regulation through psychosocial variables such as driving confidence, affective attitude, and instrumental attitude toward driving. DISCUSSIONS: The MOTRS model extends previous attempts to model older adults' driving by focusing on a novel target, driving self-regulation, and by including a wider range of predictors identified on the basis of the systematic literature review. This focus enables consideration of broader mobility issues and may inform new strategies to support the mobility of older adults.

Assessment method influences the severity and type of symptoms reported after self-reported mild traumatic brain injury.

OBJECTIVE: To investigate the influence of assessment method (spontaneous report versus checklist) on the report of postconcussive syndrome (PCS) symptoms after mild traumatic brain injury (mTBI). SETTING: Community. PARTICIPANTS: Thirty-six participants (58% female) with postacute self-reported mTBI (i.e., sustained 1-6 months prior to participation) and 36 age-, gender-, and ethnicity-matched controls with no history of mTBI. DESIGN: Cross-sectional. MAIN MEASURES: Spontaneous symptom report from open-ended questions and checklist endorsed symptoms from the Neurobehavioral Symptom Inventory (both measures administered online). RESULTS: Assessment method significantly affected individual symptom item frequencies (small to large effects), the number of symptoms reported, the total severity score, domain severity scores (i.e., somatic/sensory, cognitive, and affective symptom domains), and the number of participants who met a PCS caseness criterion (large effects; checklist > spontaneous report). The types of symptoms that were different between the groups differed for the assessment methods: Compared to controls, the nonclinical mTBI group spontaneously reported significantly greater somatic/sensory and cognitive domain severity scores, whilst no domain severity scores differed between groups when endorsed on a checklist. CONCLUSIONS: Assessment method can alter the number, severity, and types of symptoms reported by individuals who have sustained an mTBI and could potentially influence clinical decisions.

The role of psychological resilience and mTBI as predictors of postconcussional syndrome symptomatology.

OBJECTIVE: Resilience is 1 of several factors that are thought to contribute to outcome following mild traumatic brain injury (mTBI). This study explored the predictors of the postconcussional syndrome (PCS) symptoms that can occur following mTBI. We hypothesized that a reported recent mTBI and lower psychological resilience would predict worse reported PCS symptomatology. METHOD: 233 participants completed the Neurobehavioral Symptom Inventory (NSI) and the Brief Resilience Scale (BRS). Three NSI scores were used to define PCS symptomatology. A total of 35 participants reported an mTBI (as operationally defined by the World Health Organization) that was sustained between 1 and 6 months prior to their participation (positive mTBI history); the remainder reported having never had an mTBI. RESULTS: Regression analyses revealed that a positive reported recent mTBI history and lower psychological resilience were significant independent predictors of reported PCS symptomatology. These results were found for the 3 PCS scores from the NSI, including using a stringent caseness criterion, p < .05. Demographic variables (age and gender) were not related to outcome, with the exception of education in some analyses. CONCLUSION: The results demonstrate that: (a) both perceived psychological resilience and mTBI history play a role in whether or not PCS symptoms are experienced, even when demographic variables are considered, and (b) of these 2 variables, lower perceived psychological resilience was the strongest predictor of PCS-like symptomatology.

Evaluating the Emergence of Reverse Intraverbals in Children with Autism.

Verbal behavior plays a fundamental role in the development of complex social and communication skills. Many children diagnosed with autism spectrum disorder exhibit profound deficiencies in intraverbal repertoires and the development of social relationships. Recent studies that investigated the effects of intraverbal training on the emergence of reverse intraverbals produced mixed results (e.g., Perez-Gonzalez et al., Journal of Applied Behavior Analysis 40:697-701, 2007)). In the current study, a multiple-probe design across four participants with autism was used to evaluate the effects of intraverbal training on the emergence of reverse intraverbals. Intraverbal training consisted of multiple exemplars taught concurrently, bidirectional stimulus-response teaching formats, general case analysis, reinforcement, and a constant prompt delay (CPD) procedure. Participants were trained on intraverbal targets and probes were conducted to assess emergence of untaught reverse intraverbals. Three participants demonstrated the emergence of reverse intraverbals as a result of the intraverbal training procedures. Social validity and maintenance of target responses and emergent reverse intraverbals were assessed.

Characterizing self-reported sleep disturbance after mild traumatic brain injury.

Sleep disturbance after mild traumatic brain injury (mTBI) is commonly reported as debilitating and persistent. However, the nature of this disturbance is poorly understood. This study sought to characterize sleep after mTBI compared with a control group. A cross-sectional matched case control design was used. Thirty-three persons with recent mTBI (1-6 months ago) and 33 age, sex, and ethnicity matched controls completed established questionnaires of sleep quality, quantity, timing, and sleep-related daytime impairment. The mTBI participants were compared with an independent sample of close-matched controls (CMCs; n = 33) to allow partial internal replication. Compared with controls, persons with mTBI reported significantly greater sleep disturbance, more severe insomnia symptoms, a longer duration of wake after sleep onset, and greater sleep-related impairment (all medium to large effects, Cohen's d > 0.5). No differences were found in sleep quantity, timing, sleep onset latency, sleep efficiency, or daytime sleepiness. All findings except a measure of sleep timing (i.e., sleep midpoint) were replicated for CMCs. These results indicate a difference in the magnitude and nature of perceived sleep disturbance after mTBI compared with controls, where persons with mTBI report poorer sleep quality and greater sleep-related impairment. Sleep quantity and timing did not differ between the groups. These preliminary findings should guide the provision of clearer advice to patients about the aspects of their sleep that may change after mTBI and could inform treatment selection.

The effects of sleep restriction on executive inhibitory control and affect in young adults.

PURPOSE: Young adults regularly experience restricted sleep due to a range of social, educational, and vocational commitments. Evidence suggests that extended periods of sleep deprivation negatively impact affective and inhibitory control mechanisms leading to behavioral consequences such as increased emotional reactivity and impulsive behavior. It is less clear whether acute periods of restricted sleep produce the same behavioral consequences. METHODS: Nineteen young adults (m = 8 and f = 12) with habitual late bedtime (after 22:30 h) and wake time (after 06:30 h) completed a range of objective and subjective measures assessing sleepiness (psychomotor vigilance task and Karolinska sleepiness scale), inhibitory control (emotional go/no-go task and a balloon analog risk task), and affect (positive and negative affective schedule). Testing was counterbalanced across participants and occurred on two occasions once following restricted sleep and once following habitual sleep 1 week apart. RESULTS: Compared with habitual sleep, sleep restriction produced significantly slower performance on the psychomotor vigilance task and higher subjective ratings of sleepiness on the Karolinska sleepiness scale. Sleep restriction also caused a significant decrease in positive affect but no change in negative affect on the affective schedule. Inhibitory control efficiency was significantly differentiated, with participants showing an increase in risk taking on the balloon analog risk task, but there was no evidence of increased reactivity to negative stimuli on the emotional go/no-go task. CONCLUSIONS: Results suggest that even acute periods of sleep loss may cause deficits in affective experiences and increase impulsive and potentially high-risk behavior in young adults.