Contribution of the study of the dynamic interaction between sleep EEG and heart rate variability

Doctorat en Sciences médicalesinfo:eu-repo/semantics/nonPublishe

Comportements et troubles sexuels induits par l'alcool

Since a long time, alcohol effects on sexual behaviour interest humans. Many myths and beliefs have evolved over centuries. Before the first scientific papers, common literature and theatre highlighted the controversial effects of this beverage on sexual relationships. Recent research reports that small amounts of alcohol do not affect sexual behaviour on the contrary to popular belief of improved sexual performance and arousal. With moderate to large consumption, male and female sexual activities are impaired and characterized by a decreased sensitivity, a loss of sexual desire, and a delayed or absent orgasm and ejaculation. Alcohol is often involved in sexual assaults, but it seems to be more related to a personality disorder with impulsivity rather than a cause by itself. In accordance with the Alcohol Myopia Theory, men under alcoholic influence show a lower control of their sexual desire and impulse as well as a higher misperception of women behaviours. Environmental factors could be also involved in sexual aggression. The sexual risk behaviours are also encouraged by alcohol. However, these data are controversial and include other factors like the individual personality, the socio-cultural influence, or prevention-related programs. Despite a negative association between alcohol and sexual behaviours, studies remain controversial on the alcohol effects. Many methodological limitations are reported such that presently, generalization of the results is hazardous. Many efforts are still required to understand precisely the link between alcohol and sexuality.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Contribution of the study of the dynamic interaction between sleep EEG and heart rate variability

Doctorat en Sciences médicalesinfo:eu-repo/semantics/nonPublishe

aspects polysomnographiques et cliniques des mouvements périodiques des membres durant le sommeil

info:eu-repo/semantics/publishe

Dépression résistante au traitement: Actualité et perspective en 2017

Major depressive disorder (MDD) affects 3 to 17 % of adults. 15 to 30 % of patients with MDD suffer from treatment resistant depression (TRD). No international consensus defines TRD. The most common definition is "MDD that is not enough improved after two successive and different classes of antidepressant treatments in appropriate dose and duration". The appropriate dose corresponds to maximal dose accepted by scientific reports and clinical recommendations, while the appropriate duration is around 6 weeks. TRD is diagnosed after excluding a pseudo-resistant depression, that is related to weak compliance or to somatic and psychiatric differential diagnosis. As well as in MDD, molecular, neuro-anatomical and metabolic disturbances are involved in TRD. A decreased cerebral plasticity induced by low level of Brain-Derived Neurotrophic Factor (BDNF) is also reported. Several authors describe that the cerebral atrophy and the dopamino-glutaminergic system disturbances are more severe in TRD than in MDD. In contrast to MDD treatment, TRD treatment is most often physical treatment. Electroconvulsive therapy (ECT) followed by a tricyclic antidepressant and/or lithium is the most effective treatment. Deep brain stimulation and vagal nerve stimulation reach also a high rate of remission but they are both very invasive technique. Repetitive transcranial magnetic stimulation in TRD seems to be effective in TRD but lower than ECT. There are two majors purposes for this review. First it may help the clinician to understand the TRD's complexity and also it details the kind of treatment useful to care it.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Estimating the decomposition of predictive information in multivariate systems

In the study of complex systems from observed multivariate time series, insight into the evolution of one system may be under investigation, which can be explained by the information storage of the system and the information transfer from other interacting systems. We present a framework for the model-free estimation of information storage and information transfer computed as the terms composing the predictive information about the target of a multivariate dynamical process. The approach tackles the curse of dimensionality employing a nonuniform embedding scheme that selects progressively, among the past components of the multivariate process, only those that contribute most, in terms of conditional mutual information, to the present target process. Moreover, it computes all information-theoretic quantities using a nearest-neighbor technique designed to compensate the bias due to the different dimensionality of individual entropy terms. The resulting estimators of prediction entropy, storage entropy, transfer entropy, and partial transfer entropy are tested on simulations of coupled linear stochastic and nonlinear deterministic dynamic processes, demonstrating the superiority of the proposed approach over the traditional estimators based on uniform embedding. The framework is then applied to multivariate physiologic time series, resulting in physiologically well-interpretable information decompositions of cardiovascular and cardiorespiratory interactions during head-up tilt and of joint brain-heart dynamics during sleep

Characterization of the sleep EEG in acutely depressed men using detrended fluctuation analysis.

OBJECTIVE: The aim of the present paper is to study the fluctuations of the sleep EEG over various time scales during a specific pathological condition: major depressive episode. Focus is made on scaling behaviour, which is the signature of the absence of characteristic time scale, and the presence of long-range correlations associated to physiological constancy preservation, variability reduction and mostly adaptability. METHODS: Whole night sleep electroencephalogram signals were recorded in 24 men: 10 untreated patients with a major depressive episode (41.70+/-8.11 years) and 14 healthy subjects (42.43+/-5.67 years). Scaling in these time series was investigated with detrended fluctuation analysis (time range: 0.16-2.00s). Scaling exponents (alpha) were determined in stage 2, slow wave sleep (stages 3 and 4) and during REM sleep. Forty-five epochs of 20s were chosen randomly in each of these stages. RESULTS: The median values of alpha were lower in patients during stage 2 and SWS. CONCLUSIONS: Major depressive episodes are characterized by a modification in the correlation structure of the sleep EEG time series. The finding which shows decreasing rate of the temporal correlations being different within the two groups in stage 2 and SWS provides an electrophysiologic argument that the underlying neuronal dynamics are modified during acute depression. SIGNIFICANCE: The observed modifications in scaling behaviour in acutely depressed patients could be an explanation of the sleep fragmentation and instability found during major depressive episode.Comparative StudyJournal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe