Short-term complexity of cardiac autonomic control during sleep: REM as a potential risk factor for cardiovascular system in aging.

peer reviewedINTRODUCTION: Sleep is a complex phenomenon characterized by important modifications throughout life and by changes of autonomic cardiovascular control. Aging is associated with a reduction of the overall heart rate variability (HRV) and a decrease of complexity of autonomic cardiac regulation. The aim of our study was to evaluate the HRV complexity using two entropy-derived measures, Shannon Entropy (SE) and Corrected Conditional Entropy (CCE), during sleep in young and older subjects. METHODS: A polysomnographic study was performed in 12 healthy young (21.1+/-0.8 years) and 12 healthy older subjects (64.9+/-1.9 years). After the sleep scoring, heart period time series were divided into wake (W), Stage 1-2 (S1-2), Stage 3-4 (S3-4) and REM. Two complexity indexes were assessed: SE(3) measuring the complexity of a distribution of 3-beat patterns (SE(3) is higher when all the patterns are identically distributed and it is lower when some patterns are more likely) and CCE(min) measuring the minimum amount of information that cannot be derived from the knowledge of previous values. RESULTS: Across the different sleep stages, young subjects had similar RR interval, total variance, SE(3) and CCE(min). In the older group, SE(3) and CCE(min) were reduced during REM sleep compared to S1-2, S3-4 and W. Compared to young subjects, during W and sleep the older subjects showed a lower RR interval and reduced total variance as well as a significant reduction of SE(3) and CCE(min). This decrease of entropy measures was more evident during REM sleep. CONCLUSION: Our study indicates that aging is characterized by a reduction of entropy indices of cardiovascular variability during wake/sleep cycle, more evident during REM sleep. We conclude that during aging REM sleep is associated with a simplification of cardiac control mechanisms that could lead to an impaired ability of the cardiovascular system to react to cardiovascular adverse events

Relevância clínica de pesadelos em pacientes com transtorno depressivo

INTRODUCTION: Several studies have suggested a strong association between nightmares and depressive disorder. The aim of this study was to detect the prevalence of nightmares among patients with depressive disorders and to observe its relationship with age, sex, duration of disease, severity of depression and suicidal ideation. METHODS: Sixty patients were interviewed and assessed by means of the Beck Depression Inventory (BDI) and the Beck Scale for Suicidal Ideation (SSI). Nightmares were assessed according to the DSM-IV criteria for Nightmare Disorder. Data analyses were performed by Descriptive analyses and Students t-test with statistical significance at pINTRODUÇÃO: Diversos estudos sugerem uma estreita relação entre pesadelos e o transtorno depressivo. O objetivo deste estudo foi detectar a prevalência de pesadelos em pacientes com transtorno depressivo e observar sua relação com idade, sexo, tempo de doença, gravidade do quadro depressivo e ideação suicida. MÉTODOS: Sessenta pacientes foram entrevistados e avaliados por meio da escala de depressão de Beck (EDB) e da escala de ideação suicida de Beck (EIS). Os pesadelos foram avaliados segundo os critérios da DSM-IV para transtorno de pesadelos. A análise dos dados foi realizada mediante a análise descritiva e o teste-t de Student, com nível de significância de 5%. RESULTADOS: Nesta amostra, houve prevalência de 60% de pesadelos nos pacientes, com predominância entre mulheres. Os pacientes deprimidos com pesadelos apresentaram significativamente (p < 0,05) maior tempo de doença depressiva, média de pontuações mais elevadas nas duas escalas e nos itens sobre sensação de fracasso, alterações de sono e ideação suicida da EDB. DISCUSSÃO: Na amostra de pacientes deprimidos estudada, a presença de pesadelos foi relacionada com a gravidade do quadro depressivo e a presença de ideação suicida clinicamente marcante. Assim, os pesadelos devem ser considerados na avaliação de pacientes com transtorno depressivo

Transtornos do sono em pacientes ambulatoriais com depressão

CONTEXTO: Os transtornos do sono são uma característica marcante do transtorno depressivo e podem ocorrer nos primeiros estágios da depressão, antecipá-la ou ser um sintoma residual. OBJETIVO: Avaliar as queixas de transtornos do sono em pacientes ambulatoriais com transtorno depressivo de um hospital geral. MÉTODOS: Foi realizado um estudo observacional, transversal, com uma amostra de 70 pacientes (44 mulheres e 26 homens) com diagnóstico de transtorno depressivo, segundo os critérios da DSM-IV. Os pacientes foram entrevistados e avaliados por meio da ficha de identificação do questionário de hábitos de sono e do Inventário de Depressão de Beck (IDB). RESULTADOS: Neste estudo, 50 (71,3%) pacientes apresentaram recorrência das queixas de transtornos do sono. A média dos escores obtida no IDB foi 35,83±8,85, com diferenças significativas entre os pacientes com (38,50±8,70) e sem (29,60±7,80) recorrência (p ; 3 episódios (p ; 3 episodes (p < 0.05). In this study, 49 (70%) patients had insomnia and 21 (30%) had excessive sleepiness. Significant differences were observed between the mean duration in months of the sleep disorders (7.16+2.10) and the depressive disorder (6.12+1.90) (p < 0.05). CONCLUSION: In the study sample, recurrence of sleep disorder complaints was high and significantly associated with severe depression. Insomnia was prevalent and the mean duration of sleep disorders was higher in relation to depressive disorder

The sleep-circadian interface:a window into mental disorders

Sleep, circadian rhythms, and mental health are reciprocally interlinked. Disruption to the quality, continuity, and timing of sleep can precipitate or exacerbate psychiatric symptoms in susceptible individuals, while treatments that target sleep—circadian disturbances can alleviate psychopathology. Conversely, psychiatric symptoms can reciprocally exacerbate poor sleep and disrupt clock-controlled processes. Despite progress in elucidating underlying mechanisms, a cohesive approach that integrates the dynamic interactions between psychiatric disorder with both sleep and circadian processes is lacking. This review synthesizes recent evidence for sleep—circadian dysfunction as a transdiagnostic contributor to a range of psychiatric disorders, with an emphasis on biological mechanisms. We highlight observations from adolescent and young adults, who are at greatest risk of developing mental disorders, and for whom early detection and intervention promise the greatest benefit. In particular, we aim to a) integrate sleep and circadian factors implicated in the pathophysiology and treatment of mood, anxiety, and psychosis spectrum disorders, with a transdiagnostic perspective; b) highlight the need to reframe existing knowledge and adopt an integrated approach which recognizes the interaction between sleep and circadian factors; and c) identify important gaps and opportunities for further research

Evaluation of Visual Comfort and Mental Effort under Different Light Conditions for Ultraviolet-Absorbing and Additional Blue-Filtering Intraocular Lenses for Cataract Surgery

peer reviewedPatients and Methods Patients with an ultraviolet blocking lens (UV) (n = 5) or blue filter lens (BB) (n = 8) after intraocular lens (IOL) replacement for cataract and age-adjusted controls (AACs) (n = 16) underwent a balanced crossover within-subject design. After 1.5 h of dark adaptation, they were exposed to polychromatic light at 6500 K (blue-enriched) and 2500 K and 3000 K (non-blue-enriched) for 2 hours in the evening. Visual comfort and mental effort were repeatedly assessed by the Visual Analogue Scale (0-100) and the Visual Comfort and Mental Effort Rating Scale (0-100) for each light condition. The results were compared using mixed model analysis. Results The mean (± SD) age for AAC and patients with UV or BB was 69.8 ± 6.2 y, 70.8 ± 4 y, and 63.6 ± 5.6 y, respectively. Irrespective of the light condition, patients with UV and BB felt mentally more tired during the experiments compared to AACs (F = 6.15, p = 0.003). However, patients with BB were mentally more motivated to perform the exercises compared to patients with UV and AACs (F = 8.1, p < 0.001). Patients with BB perceived ambient light as less glary (F = 4.71, p = 0.01) than patients with UV. Blue ambient light was felt less intensely in patients with BB (F = 2.51, p = 0.042) compared to those with UV and the AACs. Conclusion Lens replacement in older cataract patients may increase visual comfort and minimize mental effort. While subtle, the magnitude of these effects may depend on the type of intraocular lens. BB intraocular lenses may have potential benefits, as ambient light is perceived as having less glare and less visual tension. © Georg Thieme Verlag KG Stuttgart. New York

A finite-element reciprocity solution for EEG forward modeling with realistic individual head models

peer reviewedHighlights • Creates EEG forward models suitable for high-resolution source localization. • Automatic T1-based whole-head finite element meshing and leadfield computation. • Pipelines can incorporate conductivity tensors from diffusion-weighted images. • Open-source toolbox shared under a permissive software license. • Accuracy comparable to SimBio FEM and superior to OpenMEEG BEM solutions