Somnolence, fatigue et fonctionnement attentionnel suite à un traumatisme craniocérébral

Tableau d’honneur de la Faculté des études supérieures et postdoctorales, 2012-2013.Cette thèse doctorale s’intéresse aux conséquences à long terme suite à un traumatisme craniocérébral (TCC) modéré à sévère. L’étude vise à documenter la présence, la sévérité et les corrélats des problèmes de somnolence, de fatigue et de sommeil. Un second objectif est d’évaluer les aspects attentionnels de vitesse de traitement de l’information, d’attention sélective et d’attention soutenue. Dans un troisième temps, la thèse a pour but d’explorer les relations entre la somnolence, la fatigue et le sommeil, d’une part, et le fonctionnement attentionnel, d’autre part. Vingt-deux adultes ayant subi un TCC modéré à sévère entre 1 et 11 ans avant leur implication dans l’étude sont comparés à 22 participants contrôles appariés selon l’âge, le sexe et le niveau d’éducation. L’étude comporte un enregistrement polysomnographique nocturne et diurne, trois tests neuropsychologiques d’attention, une tâche sur un simulateur de conduite automobile, et des mesures subjectives de somnolence, de fatigue et de sommeil. Les résultats du premier article démontrent un niveau de fatigue significativement plus élevé chez les participants TCC, alors que les groupes ne diffèrent pas sur les mesures de somnolence objective ou subjective. L’impact des problèmes de somnolence sur la productivité générale, le temps passé au lit dans la nuit, et la fréquence et la durée des siestes dans la journée sont significativement plus élevés dans le groupe TCC. Les résultats du deuxième article révèlent que les participants TCC performent significativement moins bien aux mesures de vitesse de traitement de l’information et d’attention soutenue dérivées des tests neuropsychologiques et de la tâche de conduite simulée, alors que les groupes ne diffèrent pas sur l’attention sélective. Des associations significatives sont démontrées entre une performance attentionnelle inférieure et une moins bonne continuité du sommeil ou un niveau plus élevé de somnolence, principalement dans le groupe TCC. Aucune relation n’est observée entre les mesures d’attention et de fatigue. Les résultats de la thèse suggèrent que la fatigue est un symptôme plus proéminent que la somnolence plusieurs années après un TCC modéré à sévère. Le recours à des stratégies compensatoires telles que d’augmenter les opportunités de sommeil semble être une pratique courante. Les résultats confirment que la vitesse de traitement de l’information demeure affectée plusieurs années après un TCC et indiquent que l’attention soutenue pourrait aussi être compromise. L’attention semble être reliée à la continuité du sommeil et à la somnolence, suggérant que les patients, cliniciens et chercheurs devraient porter attention à cette interaction.This doctoral dissertation focused on sleepiness, fatigue, sleep, and attention in the long term following traumatic brain injury (TBI). The study aimed to document the presence and severity of sleepiness, fatigue and sleep problems. Another objective was to assess the attentional aspects of speed of information processing, selective attention, and sustained attention. The dissertation was also intended to explore the relationships between sleepiness, fatigue, and sleep, on one hand, and attentional functioning, on the other hand. Twenty-two adults who had sustained a moderate to severe TBI between 1 and 11 years prior to their enrolment in the study were compared to 22 control participants matched on age, sex, and education. The main outcome measures included nighttime and daytime polysomnographic recordings, three neuropsychological tests of attention, a driving simulator task, and subjective measures of sleepiness, fatigue, and sleep. Results of the first empirical paper indicated a significantly higher level of fatigue in TBI participants compared to controls, whereas groups did not differ on objective or subjective sleepiness measures. The impact of sleepiness on general productivity, the time spent in bed at night, and the frequency and duration of daytime napping were greater in the TBI group. Results of the second empirical paper revealed a poorer performance in TBI compared to control individuals on measures tapping speed of information processing and sustained attention derived from the neuropsychological tests and the driving simulator task, while groups did not differ on selective attention. Significant correlations were observed between poorer attentional performance and poorer sleep continuity or higher levels of sleepiness, mainly in the TBI group. No relationship was found between cognitive performance and subjective fatigue. This dissertation suggests that fatigue is a more prominent symptom than sleepiness when assessed several years after TBI. The use of compensatory strategies such as increasing sleep opportunities appears to be a common practice. Results add to the existing evidence that speed of information processing is still impaired several years after TBI and indicate that sustained attention may also be compromised. Attention seems to be associated with sleep continuity and daytime sleepiness, suggesting that patients, clinicians, and researchers alike should take notice of this interaction

Sleepiness and fatigue following traumatic brain injury

Objectives : To compare individuals with traumatic brain injury (TBI) to healthy controls (CTLs) on measures of sleepiness, fatigue, and sleep, and explore correlates of sleepiness and fatigue separately for each group. Methods : Participants were 22 adults with moderate/severe TBI (time since injury ⩾1 year; mean = 53.0 ± 37.1 months) and 22 matched healthy CTLs. They underwent one night of polysomnographic (PSG) recording of their sleep followed the next day by the Maintenance of Wakefulness Test (MWT). They also completed a 14-day sleep diary, the Epworth Sleepiness Scale (ESS), the Functional Outcomes of Sleep Questionnaire (FOSQ), and the Multidimensional Fatigue Inventory (MFI). Results : There were no significant group differences on measures of objective (MWT) or subjective (ESS) sleepiness, both groups being quite alert. However, TBI participants reported greater consequences of sleepiness on their general productivity (FOSQ), spent more time in bed at night, and napped more frequently and for a longer time during the day. Subjective fatigue was significantly higher in TBI participants on the general, physical, and mental fatigue MFI subscales. There were no between-group differences on any sleep parameters derived either from PSG or sleep diary. Conclusions : Fatigue appeared to be a more prominent symptom than sleepiness when assessed between 1 and 11 years after TBI. Participants with TBI used compensatory strategies such as increasing time spent in bed and daytime napping in this sample. Future research should document the time course of sleepiness and fatigue after TBI and investigate treatment options

Insomnia and daytime cognitive performance : a meta-analysis

Objectives : Individuals with insomnia consistently report difficulties pertaining to their cognitive functioning (e.g., memory, concentration). However, objective measurements of their performance on neuropsychological tests have produced inconsistent findings. This meta-analysis was conducted to provide a quantitative summary of evidence regarding the magnitude of differences between individuals with primary insomnia and normal sleepers on a broad range of neuropsychological measures. Methods : Reference databases (PubMed, PsycInfo, Dissertation Abstracts International) were searched for studies comparing adults with primary insomnia to normal sleepers on neuropsychological measures. Dependent variables related to cognitive and psychomotor performance were extracted from each study. Variables were classified independently by two licensed neuropsychologists according to the main cognitive function being measured. Individual effect sizes (Cohen's d) were weighted by variability and combined for each cognitive function using a fixed effects model. Average effect sizes and their 95% confidence intervals were computed for each cognitive function. Results : Twenty-four studies met inclusion criteria, for a total of 639 individuals with insomnia and 558 normal sleepers. Significant impairments (p < 0.05) of small to moderate magnitude were found in individuals with insomnia for tasks assessing episodic memory (ES = −0.51), problem solving (ES = −0.42), manipulation in working memory (ES = −0.42), and retention in working memory (ES = −0.22). No significant group differences were observed for tasks assessing general cognitive function, perceptual and psychomotor processes, procedural learning, verbal functions, different dimensions of attention (alertness, complex reaction time, speed of information processing, selective attention, sustained attention/vigilance) and some aspects of executive functioning (verbal fluency, cognitive flexibility). Conclusion : Individuals with insomnia exhibit performance impairments for several cognitive functions, including working memory, episodic memory and some aspects of executive functioning. While the data suggests that these impairments are of small to moderate magnitude, further research using more ecologically valid measures and normative data are warranted to establish their clinical significance

Anxiety following mild traumatic brain injury

Purpose/Objective: The goals of the present study were (1) to document the prevalence of anxiety-related disorders and anxiety symptoms at 4, 8, and 12 months post-injury in individuals with mild traumatic brain injury (mTBI) while considering pre-injury history of anxiety disorders and (2) to verify whether the presence of anxiety in the first months following mTBI was associated with more symptoms present one year after the injury. Research Method/Design: One hundred and twenty participants hospitalized after an accident and having sustained mTBI were assessed at 4, 8, and 12 months post-accident with the Mini-International Neuropsychiatric Interview, the Hospital Anxiety and Depression Scale and questionnaires assessing fatigue, irritability, perceived stress, cognitive difficulties, depression, insomnia, and pain. Results: At 4 months, 23.8% of participants presented with at least one anxiety-related disorder compared to 15.2% at 8 months and 11.2% at 12 months. Overall, 32.5% presented with at least one anxiety disorder over the first 12 months post-mTBI. Participants with a history of anxiety (20.5%) were significantly more anxious following their accident. Individuals who were anxious 4 months after the accident presented with more symptoms in different areas 12 months post-injury compared to non-anxious individuals. Conclusions/Implications: The present results highlight that anxiety should be evaluated and managed carefully as it appears to be a key factor in the persistence of other mTBI-related symptom

Efficacité d'un auto-traitement pour l'insomnie

À Cette étude évalue l’efficacité d’une intervention minimale pour l’insomnie prenant la forme d’un auto-traitement cognitivo-comportemental. Cent quatre-vingt-douze participants avec insomnie et provenant d’une étude épidémiologique ont été assignés aléatoirement à une condition d’auto-traitement ou à une condition contrôle sans traitement. Le traitement consistait en six modules, chacun couvrant un aspect essentiel du traitement cognitivo-comportemental de l’insomnie, envoyés par la poste de façon hebdomadaire. Les participants des deux groupes ont complété des agendas du sommeil et des questionnaires avant, immédiatement après et six mois après le traitement. Les résultats ont démontré une amélioration significative sur plusieurs variables reliées au sommeil pour le groupe traitement, alors que le groupe contrôle est demeuré inchangé. Les changements se sont maintenus au suivi de six mois pour le groupe traitement. Bien que les changements aient été modestes de façon générale, un nombre significativement plus élevé de participants du groupe traitement ont eu une amélioration cliniquement significative de leur sommeil. L’appréciation du traitement, l’observance des procédures et les prédicteurs potentiels du changement ont également été évalués. Les résultats de cette étude documentent les bienfaits d’une intervention minimale chez un échantillon hétérogène de personnes souffrant d’insomnie.This study investigated the effects of a cognitive-behavioral self-help intervention for insomnia. Participants were 192 adults with insomnia randomly selected from a larger epidemiological study. They were randomized to either a self-help treatment condition or a no-treatment control condition. The treatment consisted of six booklets, each covering a component of cognitive behavior therapy, mailed weekly. All participants kept a daily sleep diary for two weeks and completed several measures before, after treatment, and for a six-month follow-up. Results showed significant improvements on many sleep-related variables for the treatment condition, while the control group remained stable. Changes were maintained at follow-up. Although improvements were generally modest, there were more participants with a clinically significant sleep improvement in the treatment group than in the control group. Treatment satisfaction and compliance, as well as potential predictors of sleep changes were also assessed. These results document the benefits of a minimal intervention for insomnia with an heterogeneous sample of insomnia sufferers

Sleep disturbances in older adults with mild cognitive impairment

Background: Normal aging and dementia are characterized by increased prevalence of sleep disorders and alterations of both sleep continuity and architecture. However, little is still known about the nature of sleep in mild cognitive impairment (MCI), which is presumably situated on the continuum from healthy aging to dementia. This unsystematic review summarizes the current literature on the prevalence and severity of sleep disturbances in MCI. Methods: Eighteen studies addressing sleep/night-time disturbances among other neuropsychiatric symptoms in individuals with MCI were identified through a search of databases and an examination of reference lists of selected papers. Fifteen of those studies reported data on prevalence or severity of sleep/night-time disturbances. Results: Results indicated that 14–59% of patients with MCI had sleep disturbances. These disturbances were often identified as one of the four most prevalent neuropsychiatric symptoms of MCI and were considered as clinically significant in some studies. In addition, there was some evidence that the prevalence of sleep disturbances in MCI is intermediate between that of normal aging and dementia. Longitudinal data suggest that sleep problems are associated with both incident MCI and dementia. Conclusions: These findings support the hypothesis that sleep disturbances are one of the core non-cognitive symptoms of MCI. It remains to be known whether sleep problems could help to identify those individuals with MCI who will eventually develop dementia. Studies characterizing sleep more systematically are needed to verify this proposition and to clarify the associations between sleep disturbances and other neuropsychiatric symptoms of MCI

Fatigue in the first year after traumatic brain injury : course, relationship with injury severity, and correlates

The objectives of this study were to document the evolution of fatigue in the first year after traumatic brain injury (TBI), and to explore correlates of fatigue. Participants were 210 adults who were hospitalised following a TBI. They completed questionnaires 4, 8, and 12 months post-injury, including the Multidimensional Fatigue Inventory (MFI). Participants with severe TBI presented greater mental and physical fatigue, and reduced activity compared to participants with moderate TBI. For all MFI subscales except reduced motivation, the general pattern was a reduction of fatigue levels over time after mild TBI, an increase of fatigue after severe TBI, and stable fatigue after moderate TBI. Fatigue was significantly associated with depression, insomnia, cognitive difficulties, and pain at 4 months; the same variables and work status at 8 months; and depression, insomnia, cognitive difficulties, and work status at 12 months. These findings suggest that injury severity could have an impact on the course of fatigue in the first year post-TBI. Depression, insomnia, and cognitive difficulties remain strong correlates of fatigue, while for pain and work status the association with fatigue evolves over time. This could influence the development of intervention strategies for fatigue, implemented at specific times for each severity subgroup

Predictability of Sleep in Patients with Insomnia

Study Objectives: To evaluate whether the night-to-night variability in insomnia follows specific predictable patterns and to characterize sleep patterns using objective sleep and clinical variables. Design: Prospective observational study. Setting: University-affiliated sleep disorders center. Participants: 146 participants suffering from chronic and primary insomnia. Measurements and Results: Daily sleep diaries were completed for an average of 48 days and self-reported questionnaires once. Three nights were spent in the sleep laboratory for polysomnographic (PSG) assessment. Sleep efficiency, sleep onset latency, wake after sleep onset, and total sleep time were derived from sleep diaries and PSG. Time-series diary data were used to compute conditional probabilities of having an insomnia night after 1, 2, or 3 consecutive insomnia night(s). Conditional probabilities were submitted to a k-means cluster analysis. A 3-cluster solution was retained. One cluster included 38 participants exhibiting an unpredictable insomnia pattern. Another included 30 participants with a low and decreasing probability to have an insomnia night. The last cluster included 49 participants exhibiting a high probability to have insomnia every night. Clusters differed on age, insomnia severity, and mental fatigue, and on subjective sleep variables, but not on PSG sleep variables. Conclusion: These findings replicate our previous study and provide additional evidence that unpredictability is a less prevalent feature of insomnia than suggested previously in the literature. The presence of the 3 clusters is discussed in term of sleep perception and sleep homeostasis dysregulation

Attention following traumatic brain injury : neuropsychological and driving simulator data, and association with sleep, sleepiness, and fatigue

The objectives of this study were to compare individuals with traumatic brain injury (TBI) and healthy controls on neuropsychological tests of attention and driving simulation performance, and explore their relationships with participants’ characteristics, sleep, sleepiness, and fatigue. Participants were 22 adults with moderate or severe TBI (time since injury ≥ one year) and 22 matched controls. They completed three neuropsychological tests of attention, a driving simulator task, night-time polysomnographic recordings, and subjective ratings of sleepiness and fatigue. Results showed that participants with TBI exhibited poorer performance compared to controls on measures tapping speed of information processing and sustained attention, but not on selective attention measures. On the driving simulator task, a greater variability of the vehicle lateral position was observed in the TBI group. Poorer performance on specific subsets of neuropsychological variables was associated with poorer sleep continuity in the TBI group, and with a greater increase in subjective sleepiness in both groups. No significant relationship was found between cognitive performance and fatigue. These findings add to the existing evidence that speed of information processing is still impaired several years after moderate to severe TBI. Sustained attention could also be compromised. Attention seems to be associated with sleep continuity and daytime sleepiness; this interaction needs to be explored further

Variability and predictability in sleep patterns of chronic insomniacs

Sleep of chronic insomniacs is often characterized by extensive night-to-night variability. To date, no study has examined this variability with long series of daily sleep data. The present study examined night-to-night variability with a sample of 106 participants meeting DSM-IV diagnostic criteria for persistent primary insomnia. Participants completed daily sleep diaries for an average of 31 days (range: 18–56). Sleep efficiency, sleep onset latency and wake after sleep onset were derived from this measure. Despite evidence of extensive night variability, results showed that sleep patterns could be classified in three clusters. The first one was characterized by a high probability of having poor sleep, the second one by a low and decreasing probability, and the third one by a constant median probability of having a poor sleep, which is an unpredictable sleep pattern. In the first cluster, poor sleep was expected each night for patients with a predominance mixed insomnia including the three insomnia subtypes. In the second cluster, patients presented moderate insomnia, sleep-onset latency below the threshold level and a predominance of sleep-maintenance insomnia. In the third pattern, poor nights seemed unpredictable for patients with moderate to severe insomnia associated with the lowest proportion of sleep-maintenance insomnia. Overall, sleep was predictable for about two-thirds of individuals, whereas it was unpredictable for about one-third. These findings confirm the presence of extensive variability in the sleep of chronic insomniacs and that poor sleep may be predictable for some of them. Additional research is needed to characterize those sleep patterns in terms of clinical features and temporal course