Conséquences de l'évolution de la prise en charge de la mort subite du nourrisson entre 1971-1976 et 2000-2005 dans le département du Rhône

LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

La mort subite du nourrisson(MSN) Données récentes en physiologie

Prevention campaigns to avoid risk factors for the occurrence of sudden infant death syndrome (SIDS) during sieep have ied to a significant decrease in the number of infants dying suddeniy and unexpectedly during sieep. Despite a growing amount of evidence, the understanding of the mechanisms responsible for SIDS is stilt iargeiy incomplete. We will review the most recent epidemiotogicai, electrophysiologicai, genetic and pathological research on this topic. From these data, a comprehensive model for SIDS has been proposed: the death wouid resuit from the combination of three factors (a prenatal vulnerability, a critical developmental period and an exogenous postnatal stress) and three potential mecbanisms (deficiencies in breathing, autonomie and sleep-wake controis). As arousal represents the last chance of survival when an infant is exposed to a life-threatening challenge during sleep, failure to arouse could be involved in the final pathway of SIDS. An infant could be vulnerable to SIDS because of a deficiency in cardio-respiratory or in sleep/wake behaviour controis during sleep. Genetic, metaboiic, nutritbnal or toxic prenatal brainstem injury could be responsible for these deficits. The infant's vulnerability lies latent until he/she enfers the critical developmental period from 2 to 6 months when significant changes in sleep-wake, breathing and autonomie controls occur. The accident has a greater probability of occurring when the infant is exposed to an infection, or an unfavourable environmental factor which enhances the immature cardio respiratory and sleep/wake behaviours of the infant. © 2005 Elsevier Masson SAS. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Sudden Infant Death Syndrome: From Epidemiology to Pathophysiology

Despite the dramatic decline in the incidence of sudden infant death syndrome (SIDS) by 50-90% over the past two decades, SIDS continues to be the leading cause of death in infants aged between 1 month and 1 year in developed countries. We will review the most recent epidemiological, electrophysiological, genetic, and pathological research on this topic. From these data, a comprehensive model for SIDS has been proposed: the death would result from the combination of three factors (a prenatal vulnerability, a critical developmental period, and an exogenous postnatal stress) and three potential mechanisms (deficiencies in breathing, autonomic, and sleep-wake controls).An infant could be vulnerable to SIDS because of a deficiency in the medullary 5-hydroxytryptamine (5-HT) system due to environmental or genetic causes. This system has a key role in homeostatic functions involving respiratory, cardiovascular, and arousal controls. The infant's vulnerability lies latent until he/she enters the critical developmental period from 2 to 6 months when significant changes in sleep-wake, breathing, and autonomic controls occur. The accident has a greater probability of occurring when the infant is exposed to an infection, or an unfavorable environmental factor which enhances the immature cardio respiratory and sleep/wake behaviors of the infant.SCOPUS: ch.binfo:eu-repo/semantics/publishe

Sudden infant death syndrome from epidemiology to pathophysiology

SCOPUS: re.jinfo:eu-repo/semantics/publishe

QT interval prolongation in future SIDS victims: a polysomnographic study.: QT intervals in future SIDS victims

International audienceOBJECTIVE: Previous data have suggested that a prolonged QTc interval during the first days of life can be associated with some cases of sudden infant death syndrome (SIDS). Analysis of heart rate variability during sleep in future SIDS victims has shown findings compatible with an imbalance in autonomic tone. We hypothesized that some future SIDS infants could have longer QTc intervals during sleep, compared with healthy control infants, and that this difference would correlate with the autonomic imbalance already found in these infants. METHODS: QTc intervals and a heart rate autoregressive power spectral analysis were calculated during the same periods in the polysomnographic sleep recordings of 18 infants who eventually died of SIDS and of 18 control infants. The control infants were matched for sex, gestational age, postnatal age, birth weight, and sleep position. The median postnatal age was 8 weeks. RESULTS: Compared with control infants, future SIDS victims were characterized by having longer QTc intervals during total sleep (P = 0.019), rapid eye movement sleep (P = 0.045) and non-rapid eye movement sleep (P = 0.029). When the night was divided into 3 equal parts, this difference was always present but was most marked during the last part of the night. There was, respectively, a negative and a positive correlation between parasympathetic activity and sympathovagal balance and median and maximum QTc interval values. CONCLUSION: Compared with QTc intervals in matched control infants, QTc intervals were increased in future SIDS victims. Such a prolongation could be related to the autonomic dysfunction already reported in these patients

Sudden infant death syndrome from epidemiology to pathophysiology: Exploring the connections

The sudden and unexplained death of sleeping infants aged less than 1 year, the sudden infant death syndrome (SIDS), is still the principal cause of postneonatal mortality in many industrialized countries. Since initiation of education and information campaigns to inform the public on preventable risk factors, SIDS incidence has dropped significantly in most countries. Questions have, however, been raised on the physiological mechanisms underlying the environmental factors increasing the risk for SIDS. From the scientific literature, it appears that various mechanisms responsible for the control of respiratory, cardiac, thermoregulation, neurovegetative, and waking systems could be impaired before or after birth of future victims of SIDS. To understand how various factors contribute to SIDS deaths, we studied the characteristics of sleeping infants in two different populations, in future SIDS victims and in healthy infants exposed to conditions known to favor SIDS. This paper will review research carried out by our laboratory over the past 20 years.SCOPUS: ch.binfo:eu-repo/semantics/publishe

QT interval prolongation in future SIDS victims: A polysomnographic study

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Biallelic PPA2 Mutations Cause Sudden Unexpected Cardiac Arrest in Infancy

International audienceSudden unexpected death in infancy occurs in apparently healthy infants and remains largely unexplained despite thorough investigation. The vast majority of cases are sporadic. Here we report seven individuals from three families affected by sudden and unexpected cardiac arrest between 4 and 20 months of age. Whole-exome sequencing revealed compound heterozygous missense mutations in PPA2 in affected infants of each family. PPA2 encodes the mitochondrial pyrophosphatase, which hydrolyzes inorganic pyrophosphate into two phosphates. This is an essential activity for many biosynthetic reactions and for energy metabolism of the cell. We show that deletion of the orthologous gene in yeast (ppa2Δ) compromises cell viability due to the loss of mitochondria. Expression of wild-type human PPA2, but not PPA2 containing the mutations identified in affected individuals, preserves mitochondrial function in ppa2Δ yeast. Using a regulatable (doxycycline-repressible) gene expression system, we found that the pathogenic PPA2 mutations rapidly inactivate the mitochondrial energy transducing system and prevent the maintenance of a sufficient electrical potential across the inner membrane, which explains the subsequent disappearance of mitochondria from the mutant yeast cells. Altogether these data demonstrate that PPA2 is an essential gene in yeast and that biallelic mutations in PPA2 cause a mitochondrial disease leading to sudden cardiac arrest in infants