Sommeil et nutrition chez le nourrisson et le jeune enfant

In infants, sleep/wake rhythms and the feeding pattern are closely related. Establishing stable night sleep depends on time givers. The decrease and later suppression of night feeds are part of the process. Breast fed infants keep waking up at night later than bottle fed peers, and they are fed more frequently during the nocturnal waking occasions. After the age of six months, night awaking is likely induced by environmental factors (sleep conditioning, night eating syndrome, sharing the parents’ bed, absence of limits) rather than by the composition of the mother's milk. Cow's milk intolerance as well as some dietary mistakes (low fat intake, excessive protein intake, low or high feed volumes) can induce true insomnias in infants.     

Propriospinal myoclonus at sleep onset

AIMS: To describe the clinical and polygraphic features of propriospinal myoclonus (PSM) at sleep onset. MATERIAL AND METHODS: PSM was first described in 1997 in patients with jerks occurring in the relaxation period preceding sleep. EMG showed jerks to arise in spinally innervated muscles, propagating thereafter to rostral and caudal muscles at a low speed, typical of propriospinal pathways. RESULTS: PSM arose when EEG alpha activity spread over the scalp and disappeared during either active wakefulness or actual sleep. In some patients EMG activity could sometimes remain localized to the abdominal muscles, propagating to other segments only in fully developed jerks. Neurological examination, brain and spinal MRI were usually normal and clonazepam afforded partial improvement. PSM has been recently observed also in restless legs syndrome, during relaxed wakefulness preceding falling asleep, coexisting with motor restlessness and sensory discomfort. PSM disappeared when spindles and K-complexes and typical Periodic Limb Movements appeared with EMG activity limited to leg muscles, without propriospinal propagation. CONCLUSIONS: Conceivably, PSM arises in axial muscles due to some spinal generator set into motion by facilitating influences characteristic of the wake-sleep transition and then undergoes multimeric propriospinal propagation. In the International Classification of Sleep Disorders (ICSD-2), PSM is listed in chapter VII, among the "Isolated symptoms, apparently normal variants and unresolved issues".     

Temporal characteristics of the augmentation of paradoxal sleep following learning in the rat

In a previous work, we have shown that an avoidance conditioning is followed by an increased number of Paradoxical Sleep (PS) phases during the first hour after learning. In Experiment 1, sleep is experimentally delayed after each conditioning session. When sleep is delayed for 180 min, learning is severely impaired and PS doesn't increase; but the 90-min sleep delay after the conditioning session is followed by the same PS increase as that when sleep is free immediately after learning. In Experiment 2, we show that a 90-min free sleep period, between learning and a 180-min sleep deprivation allowed a learning as good as that without any sleep deprivation. In our experimental conditions, PS increase after avoidance conditioning is brief and immediate when sleep is possible and if it begins less than 180 min after learning.     

Concomitants physiologiques de l'apprentissage et sommeil paradoxal consécutif,chez le chat

During avoidance conditioning in the Cat, arousal, heart rate and respiratory reactions produced by the conditioned stimulus (CS) were recorded. The development of these reactions was compared with the paradoxical sleep (PS) length measured between the trials of each experimental session. The results of this analysis point to the existence of a critical learning period characterised by a high rate of central and peripheral reactions and by an increase in PS length. This period precedes the stabilization of performances. The functional relationship of these two phenomena with each other and with learning is discussed.     

Comparaison de l'effet somnogène de deux médicaments,le Ro 5-4200 et le Nitrazepam

Résumé Au cours d'une étude comparative entre l'action de 2 mg de Ro 5-4200 et de 10 mg de Nitrazepam sur les durées d'endormissement et de sommeil, 35 patients ont été observés. L'efficacité de ces deux substances dans un rapport de doses de 1 à 5 est comparable sur les deux variables observées. Toutefois, si le médicament est pris juste au moment du coucher, le Ro 5-4200 induit d'une manière significative un peu plus rapidement le sommeil que le Nitrazepam. En considérant les nuits dans leur ensemble sans tenir compte des sujets, aucune différence significative n'a été observée pour l'un ou l'autre des médicaments, en fonction de la régularité ou de l'irrégularité dans le moment de la prise. L'induction au sommeil dans ces conditions est donc peu brutale. Enfin, il existe une corrélation négative entre la durée d'endormissement et la durée de sommeil. En d'autres termes, ce sont les malades qui s'endorment le plus rapidement qui dorment le plus longtemps. Cette corrélation est significativement plus grande avec le Ro 5-4200.Nous remercions la Maison Hoffmann-La Roche (Bâle), qui nous a aimablement fourni le Ro 5-4200.     

Les accidents en France : évolution et facteurs associés

BackgroundWhatever the type of injury considered, prevention requires an improvement in health services’ awareness of risk factors. The Health Barometer is a general population survey conducted in France since 1992 to contribute to surveillance in this field. The survey's statistical power and the numerous health topics included in the questionnaire provide accurate information for healthcare professionals and decision-makers.MethodsThe Health Barometer 2010 was a nationwide telephone survey of 9110 persons representative of the 15–85-year-old population. One part of the questionnaire detailed injuries which had occurred during the past year. The numerous variables recorded enabled application of logistic regression models to explore risk factors related to different types of injury by age group. The findings were compared with the Health Barometer 2005 data to search for temporal trends of injury prevalence.ResultsThe data analysis showed that 10.3 % of the 15–85-year-olds reported an injury during the past year. This rate was higher than recorded in 2005; the increase was mainly due to domestic accidents and injuries occurring during recreational activities. Both type of injury and risk factors exhibited age-related variability. Domestic accidents and injuries occurring during recreational activities predominated in the older population and were associated with physical or mental health problems (chronic disease, diability, sleep disorders). For younger people, injuries were related to cannabis use, drunkedness, and insufficient sleep. Risk factors were also depended on type of injury: occupational accident-related injuries were linked with social disadvantage (manual worker population) whereas sports injuries were more common in the socially advantaged population.ConclusionThis survey confirms established knowledge and highlights, at different stages of life, new risk factors that contribute to injuries in France. These findings should be helpful for the development of adapted injury prevention programs, by providing a better understanding of the characteristic features of this major public health issue.     

La motricité redevient-elle normale en sommeil paradoxal ? Le trouble comportemental en sommeil paradoxal

Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by violent, or potentially violent, movements during REM sleep, corresponding to enacted dreams. During sleep monitoring, there is a partial or total loss of the normal muscle atonia during REM sleep. REM sleep behavior disorder predominantly affects elderly subjects without any other disease (idiopathic RBD, a precursor of Parkinson disease and Lewy body dementia) or suffering from various neurological and neurodegenerative diseases, mainly synucleinopathies. In addition to being a treatable cause of nocturnal injury of the patients or their bed-partners, RBD is a fantastic window into motor and cognitive control during REM sleep. Notably, parkinsonism transiently disappears during RBD. The patient's voice is louder and better articulated than when awake, and movements are rapid (but jerky) suggesting that the deleterious message from the basal ganglia to the primary motor cortex is reduced or bypassed. As we observed culturally-acquired behaviors, retired patients practicing their former work with mastered gestures, as well as sentences pronounced with appropriate prosody, gesturing, fluency, and syntax during the RBD, we suggest that these behaviors are generated by the same cortical areas as during wakefulness. This model also enables the demonstration that REM during REM sleep are coded in the same direction as the arm and hand movements, as if the dreamer were scanning the dream images. This online access to the motor and verbal dream scenario (through the video and audio monitoring), and the physiological measures (via the EEG, eye movements, muscle tone, respiration, heart rate), together with the offline access to the mental content (dream report after the awakening) constitute a triangulation for validating new hypotheses about REM sleep and dreams.