Search PubMed⌕ Search

Biomedical subjects

M J Challamel

Publications and source records attributed to M J Challamel.

At least 37 records · Page 2Linked to original sources
PubMed1982

Congenital central alveolar hypoventilation syndrome in six infants.

Six infants with congenital alveolar hypoventilation syndrome (CCHS) were seen and observed over several years. Two had an association of CCHS with Hirchsprung's disease. All infants were treated by tracheostomy and mechanical ventilation. Three infants have survived (including one with CCHS and Hirchsprung's disease). However, all survivors have required frequent rehospitalization. The infant with the longest survival (now 4 years of age) has developed significant daytime problems involving the "behavioral control" of ventilation. One infant was considered as a "near miss for sudden infant death syndrome" and became significantly symptomatic after establishment of delta (stage 3-4 non-rapid eye movement) sleep, which normally develops between 2 and 4 months of age. CCHS involves autonomic nervous system dysfunction, and the question of a defect involving the integration of chemoreceptor information more than a direct defect of the central chemoreceptor is discussed.

Chemoreceptor Cells↗
PubMed1981

[12-hour pattern of the waking state in the normal infant and in the infant who has survived the 'syndrome of sudden infant death' (author's transl)].

The authors report the results of 16 sleep EEGs carried out on 5 infants said to have survived the syndrome of sudden infant death (near-miss group) and 5 controls. The recordings were performed at 1.5 months, 3 months and 4.5 months, times when the risk of sudden death is maximum. The EEG appearance and the organization of sleep patterns have been studied in both groups. The various states of wakefulness, and the modalities of sleep and waking were subjected to statistical analysis with respect to age. The study showed no significant difference between the percentages of different states of wakefulness in the control and 'near-miss' group, but there were more sleep onsets in active sleep (REM) in this group compared with the controls and there were fewer waking periods, although when they occurred these were more prolonged.

Circadian Rhythm↗
PubMedDate not supplied

Effect of sleep stages on transiently evoked oto-acoustic emissions in infants.

Transiently evoked oto-acoustic emissions (TEOAEs) are generated by active contractions of the outer hair cells (OHC) of the organ of Corti. TEOAE are inhibited by the medial efferent olivocochlear system which originates in the brainstem and innervates the OHC. TEOAEs are a rapid non-invasive objective method of auditory screening in infants. Because in infants sleep represents 75% of their time, it was of interest to determine whether sleep stages which are induced in the brainstem could concomitantly affect TEOAEs. Repeated TEOAE recordings during polygraphic recordings of sleep stages were made on seven, 6-week-old infants. Results showed that: (i) TEOAE spectrum frequency components remained stable over sleep stages; (ii) TEOAE amplitude tended to increase during recording sessions; (iii) sleep stages (quiet, active and indeterminate sleep) did not affect TEOAE amplitude. This pilot study reveals that sleep mechanisms seem to have no effect on active OHC micromechanical properties. Therefore, in auditory screening, TEOAEs may serve to study active cochlear mechanisms in infants even during sleep which is the better time to perform recordings because of the quietness required.

Electrocardiography↗
PubMedDate not supplied

[An electroencephalographic study of the foetus during labour. Technique and interpretation (author's transl)].

The authors report their experiences in recording foetal E.E.Gs at the time of labour, based on 140 studies. They studied normal E.E.Gs and emphasise the existence of a sleep-waking pattern during dilatation. They consider the E.E.G. changes during the different stages of labour and assess the results against other techniques used to assess foetal well-being. They record the effects on the E.E.G. of various anaesthetics and analgesics given to the mother. The difficulty of the technique is stressed and they conclude that despite the obvious interest of the technique it is not currently suitable for routine obstetric practice.

Alfaxalone Alfadolone Mixture↗
PubMedDate not supplied

[Distribution of respiratory arrests in preterm and term infants (author's transl)].

Incidence, distribution and periodicity of respiratory arrests larger than or equal to 2 seconds duration were studied in relation to age and sleep states by means of polygraphic recording in 61 tracing of 44 preterm and term infants free of pathologic conditions known to increase the risk of respiratory arrests. Respiratory arrests at any infant's age were found to be more frequent during active sleep. Incidence of respiratory arrests decreases with age in all sleep states. At any age the average duration of respiratory arrest is longer in quiet sleep. When restrictive definition is applied periodic breathing was found to be a rare and probably an abnormal phenomenon not in connection with any particular sleep state. Apneas of longer than 10 seconds duration were observed rather seldon, as well as cardiac slowing coinciding with respiratory arrest or apnea. Bradypnea and poor differenciation of breathing pattern according to sleep states represent a rare and presumably abnormal finding. The authors feel that the elements observed should be considered in estimating the risk of severe apnea in infants.

Age Factors↗