Caractérisation des atteintes cognitives associées à l'insomnie chronique

Cette thèse vise à améliorer la compréhension du fonctionnement cognitif des personnes souffrant d’insomnie. Plus spécifiquement, elle vise à : 1) préciser la nature, la magnitude et la signification clinique des atteintes cognitives associées à l’insomnie, 2) explorer les différences entre les personnes souffrant d’insomnie qui présentent des plaintes cognitives et celles qui n’en présentent pas et 3) documenter les relations entre les atteintes cognitives observées, les perturbations du sommeil et les manifestations d’hyperactivation diurne associées à l’insomnie. Dans un premier temps, une méta-analyse résumant les études préexistantes a permis de mettre en évidence des différences légères à modérées entre les personnes souffrant d’insomnie et les bons dormeurs pour quelques sphères cognitives, soit la mémoire de travail (rétention et manipulation d’informations), la mémoire épisodique et la résolution de problèmes. Dans un deuxième temps, un groupe de 25 participants souffrant d’insomnie a été comparé à 16 participants sans difficultés de sommeil, appariés pour l’âge, le sexe et la scolarité. Ces participants ont dormi trois nuits consécutives en laboratoire, puis ont complété une batterie de tests cognitifs ainsi que des questionnaires évaluant la perception de leur fonctionnement cognitif et différentes manifestations d’hyperactivation diurne. Les résultats suggèrent des différences significatives de grandes magnitudes entre les personnes souffrant d’insomnie et les bons dormeurs pour certains aspects des performances attentionnelles et mnésiques, alors que les performances aux épreuves évaluant la mémoire de travail et le fonctionnement exécutif semblent préservées. La fréquence des déficits considérés cliniquement significatifs est plus élevée chez les participants souffrant d’insomnie. En outre, les personnes souffrant d’insomnie et ayant des plaintes cognitives présentent des atteintes touchant un plus grand nombre de sphères cognitives, et dont la magnitude est plus importante. Les différentes atteintes cognitives sont toutes associées aux perturbations du sommeil, et certaines sont également associées à différentes dimensions de l’hyperactivation diurne. Dans l’ensemble, les résultats de la thèse suggèrent que l’insomnie est caractérisée par des atteintes cognitives compatibles avec un léger dysfonctionnement des régions préfrontales, mais soulignent également la coexistence possible de différents profils cognitifs parmi les personnes souffrant d’insomnie. Pour certains individus, ces atteintes seraient suffisantes pour être considérées cliniquement significatives. Différentes atteintes cognitives paraissent associées à différents aspects du sommeil et des manifestations d’hyperactivation diurne, ce qui pourrait signaler la présence des mécanismes distincts.This thesis seeks to improve the understanding of cognitive functioning in individuals with insomnia. More specifically, it aims to: 1) specify the nature, magnitude and clinical significance of cognitive impairments associated with insomnia, 2) explore differences between individuals with insomnia who complain about their cognitive functioning and those who do not, and 3) document the relations between cognitive impairments, sleep disturbances and manifestations of daytime hyperarousal associated with insomnia. Two studies were completed to meet these objectives. First, a meta-analysis summarizing existing studies showed mild to moderate differences between individuals with insomnia and normal sleepers for several cognitive domains, namely working memory, episodic memory and problem solving. In the second study, a group of 25 individuals with insomnia was compared to 16 normal sleepers matched for age, gender and education. These participants spent three consecutive nights in the sleep laboratory, then completed a battery of cognitive tests as well as questionnaires assessing perception of their cognitive functioning and different manifestations of daytime hyperarousal. Results suggest significant differences of large magnitude between individuals with insomnia and normal sleepers for specific aspects of attentional and memory performance, while performance on tasks assessing working memory and executive functions is preserved. The frequency of clinically significant deficits is higher in individuals with insomnia. In addition, individuals with insomnia and cognitive complaints had cognitive impairment of larger magnitude, and in a larger number of cognitive domains. The different cognitive impairments are all associated with sleep disturbances, and some aspects of cognitive impairment are also associated with different dimensions of daytime hyperarousal. Taken together, results suggest that insomnia is characterized by cognitive impairment compatible with a mild dysfunction of prefrontal areas, but also point to a possible coexistence of different cognitive profiles among individuals with insomnia. For a number of individuals, these deficits would be sufficient to be considered clinically significant. Different cognitive impairments appear associated with different aspects of sleep and daytime hyperarousal, which could suggest distinct mechanisms

Insomnie et microstructure du sommeil : impact du traitement comportemental-cognitif

L’objet du présent mémoire consiste à évaluer l ’effet du traitement comportemental-cognitif (ICC) de l’insomnie sur la microstructure du sommeil. Un groupe de participants souffrant d ’insomnie chronique et un groupe témoin de bons dormeurs sont d'abord soumis à une évaluation polysomnographique (PSG) effectuée en laboratoire. Les personnes souffrant des 4 premiers cycles de sommeil. Les résultats confirment la présence de perturbations de la microstructure du sommeil chez les participants souffrant d ’insomnie. Ces perturbations se manifestent par une activité plus dense pour les bandes de fréquences delta, thêta, alpha, sigma, bêta et gamma durant le stade 2 et pour les bandes de fréquence delta, thêta, alpha, sigma et bêta durant les stades 3-4. Les résultats suggèrent un effet global du TCC sur la microstructure du sommeil des stades 3-4 mais cet effet ne semble pas se traduire par des changements spécifiques des rythmes évalués. Des écarts entre les bons dormeurs et les personnes souffrant d ’insomnie sont toujours présents après le traitement, mais les différences ne sont pas statistiquement significatives. Les améliorations de la continuité du sommeil sont fortement corrélées avec une augmentation de la densité des rythmes lents et modérément corrélées avec une augmentation de la densité des rythmes thêta, alpha, sigma et bêta. Les résultats suggèrent donc que le TCC peut induire des changements subtils de la microstructure du sommeil et que ces changements sont associés aux améliorations de la continuité du sommeil.The aim of this paper is to examine the effect o f the cognitive behavioral treatment (CBT) of insomnia on sleep microstracture. A group o f participants with chronic insomnia and a control group of normal sleepers are submitted to polysomnographic (PSG) assessment completed at the sleep laboratory. Participants with insomnia receive a 6-week TBC and return to the sleep laboratory for additional PSG recordings. The sleep microstructure is examined through powerspectral analysis o f the electroencephalogram (EEG) which is computed for stages 2, 3 and 4 ofthe first 4 sleep cycles. Results confirm the presence o f altered sleep microstructure inparticipants suffering from insomnia. These disruptions are evident from increased density fordelta, theta, alpha, sigma, beta and gamma bands during stage 2 and for delta, theta, alpha, sigma and beta bands during slow' wave sleep (SWS). Results suggest a global effect of CBT on themicrostructure o f SWS but this effect does not translate in specific changes within given rhythms. There are still discrepancies between participants with insomnia and normal sleepers atpost treatment but the differences no longer reach statistical significance. Improvements in sleep continuity parameters are strongly correlated with increased density in slow rhythms and moderately correlated with increased density in theta, alpha, sigma and beta rhythms. Results thus suggest that CBT could induce subtle changes in the SWS microstructure of insomnia sufferers and that such changes are associated with improved sleep continuity

Cognitive impairment in individuals with insomnia : clinical significance and correlates

Study Objectives: The aims of this study were to (1) investigate the nature of cognitive impairment in individuals with insomnia, (2) document their clinical significance, (3) examine their correlates, and (4) explore differences among individuals with insomnia with and without cognitive complaints. Design: Participants underwent 3 consecutive nights of polysomnography. On the morning following the third night, they completed a battery of questionnaires and neuropsychological tests. Participants: The sample included 25 adults with primary insomnia (mean age: 44.4 ± 11.5 y, 56% women) and 16 controls (mean age: 42.8 ± 12.9 y, 50% women) matched for sex, age, and education. Intervention: N/A. Measurement and Results: Participants completed neuropsychological tests covering attention, memory, working memory, and executive functions, as well as questionnaires assessing the subjective perception of performance, depression, anxiety, fatigue, sleepiness, and hyperarousal. There were significant group differences for the attention and episodic memory domains. Clinically significant deficits were more frequent in the insomnia group. Within the insomnia group, individuals with cognitive complaints exhibited significantly poorer performance on a larger number of neuropsychological variables. All impaired aspects of performance were significantly associated with either subjective or objective sleep continuity, and some were also independently related to sleep microstructure (i.e., relative power for alpha frequencies) or selected psychological variables (i.e., beliefs or arousal). Conclusions: These findings suggest clinically significant alterations in attention and episodic memory in individuals with insomnia. Objective deficits were more pronounced and involved more aspects of performance in a subgroup of individuals with cognitive complaints. These deficits appear associated with sleep continuity, and may also be related to sleep microstructure and dysfunctional beliefs

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

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

Tailoring and evaluating an intervention to improve shared decision-making among seniors with dementia, their caregivers, and healthcare providers: study protocol for a randomized controlled trial

Abstract Background The increasing prevalence of Alzheimer’s disease and other forms of dementia raises new challenges to ensure that healthcare decisions are informed by research evidence and reflect what is important for seniors and their caregivers. Therefore, we aim to evaluate a tailored intervention to help healthcare providers empower seniors and their caregivers in making health-related decisions. Methods In two phases, we will: (1) design and tailor the intervention; and (2) implement and evaluate it. We will use theory and user-centered design to tailor an intervention comprising a distance professional training program on shared decision-making and five shared decision-making tools dealing with difficult decisions often faced by seniors with dementia and their caregivers. Each tool will be designed in two versions, one for clinicians and one for patients. We will recruit 49 clinicians and 27 senior/caregiver to participate in three cycles of design-evaluation-feedback of each intervention components. Besides think-aloud and interview approaches, users will also complete questionnaires based on the Theory of Planned Behavior to identify the factors most likely to influence their adoption of shared decision-making after exposure to the intervention. We will then modify the intervention by adding/enhancing behavior-change techniques targeting these factors. We will evaluate the effectiveness of this tailored intervention before/after implementation, in a two-armed, clustered randomized trial. We will enroll a convenience sample of six primary care clinics (unit of randomization) in the province of Quebec and recruit the clinicians who practice there (mostly family physicians, nurses, and social workers). These clinics will then be randomized to immediate exposure to the intervention or delayed exposure. Overall, we will recruit 180 seniors with dementia, their caregivers, and their healthcare providers. We will evaluate the impact of the intervention on patient involvement in the decision-making process, decisional comfort, patient and caregiver personal empowerment in relation to their own healthcare, patient quality of life, caregiver burden, and decisional regret. Discussion The intervention will empower patients and their caregivers in their healthcare, by fostering their participation as partners during the decision-making process and by ensuring they make informed decisions congruent with their values and priorities. Trial registration ClinicalTrials.org, NCT02956694. Registered on 31 October 2016

Additional file 1: of Tailoring and evaluating an intervention to improve shared decision-making among seniors with dementia, their caregivers, and healthcare providers: study protocol for a randomized controlled trial

SPIRIT 2013 Checklist with the items addressed in the clinical trial protocol and related documents*. (DOC 137 kb

Additional file 1: of Five shared decision-making tools in 5 months: use of rapid reviews to develop decision boxes for seniors living with dementia and their caregivers

Search strategies used for each of the five decision boxes. (DOCX 40 kb