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Biomedical subjects

C Amiel-Tison

Publications and source records attributed to C Amiel-Tison.

At least 19 recordsLinked to original sources
PubMed1991

Adaptive changes in the developing brain during intrauterine stress.

Maturation of neurological performance in moderately to severely growth-retarded newborn infants (SGA) can be accelerated by 3 to 4 weeks or more when compared to the development of appropriately grown infants (AGA) of the same gestation. This is particularly the case in multiple pregnancies or pregnancies characterized by maternal hypertension. This clinical finding has been confirmed by neurophysiological studies on the maturation of brainstem auditory evoked responses (BAERs). The possible mechanisms which underly this phenomenon are not yet elucidated. Glucocorticoids, other steroid hormones and catecholamines are elevated in pregnancies with placental dysfunction, and it is known that these substances have multiple actions on neuronal maturation, particularly on mechanisms of release of neurotransmitters. These observations suggest that the acceleration of brain maturation, and lung maturation, in SGA infants reflects an adaptation of the fetus to early extrauterine life. However, if the placental dysfunction progresses, these mechanisms of adaptation will be overwhelmed by severe malnutrition and anoxia which result in cerebral lesions and risk of death. The clinical goal at the present time for obstetric management of these risk pregnancies is to distinguish between these two periods.

Animals↗
PubMed1991

[Perinatal neurology: panoramic view].

Four of the most typical anatomo-clinical syndrome of perinatal brain damage are schematically described, concerning risk circumstances, pathology, signs and symptoms, investigations and long term prognosis. The goal of this oversimplistic approach is to offer to the obstetricians some clues about expectation and decisions in various categories of risk. The relation Maturation-Brain damage, the respective role of mechanical and asphyxic insult are discussed. A rough estimation of the risk of severe sequelae according to birth weight is proposed, with implications on prevention of brain damage.

Birth Weight↗
PubMed1989

Measurement of post-operative pain and narcotic administration in infants using a new clinical scoring system.

We developed a clinical neurologic and behavioral scoring system composed of 10 items to measure the post-operative pain levels in infants: (1) sleep during preceeding hour, (2) facial expression of pain, (3) quality of cry, (4) spontaneous motor activity, (5) Spontaneous excitability, (6) flexion of fingers and toes, (7) sucking, (8) global evaluation of tone, (9) consolability and (10) sociability. Using this system, a group of infants ranging from one to seven months in age and undergoing minor surgical procedures was studied. The infants were randomly assigned to two groups: Group I received Fentanyl intravenously (3 micrograms/kg) prior to surgery, and Group II received a placebo. The infants then were studied post-operatively in the recovery room at 30, 60, 90 and 120 min intervals. Over the entire post-operative observation period, 54% of the infants in Group I had satisfactory analgesia compared to 18% in Group II. There were no significant differences in Group I and Group II in oxygenation, carbon dioxide elimination, blood pressure, heart rate or temperature.

Fentanyl↗
PubMed1988

Cerebral handicap in full-term newborns related to late pregnancy and/or labor.

The improving results of modern obstetrics, anesthesiology and immediate pediatric care have to be assessed. Clinical methods are available, providing guidelines for a simple neuro-sensorial assessment of the full-term newborn. When abnormalities are detected at the first assessment, the newborn will be assessed daily or every other day, as the symptomatology often rapidly changes. Based on these repeated evaluations, a gradation of 3 levels of severity is established, by the end of the first week: mild (1) includes tone abnormalities and hyperexcitability but no seizures and no CNS depression; moderate (2) includes CNS depression +/- isolated seizures; severe (3) includes coma and repeated seizures. Though this gradation represents an empirical cut-off in a continuum of signs and symptoms indicating brain dysfunction at birth, correlations with late outcome are reasonably good. Individual prognosis is out of our reach, specially in grade 2 infants. However, as a group estimation of late outcome, this gradation is satisfactory. Neurobehavioral competence in the full-term newborn is such that one assessment performed within normal limits in the first 3 days allows a reasonable prediction of a normal outcome, no matter how dreadful the pregnancy and/or delivery has been. Therefore neurological assessment of the full-term newborn in the first week of life can be considered as a good marker for the quality of perinatal care, and good feed-back information for the obstetrical staff.(ABSTRACT TRUNCATED AT 250 WORDS)

Birth Injuries↗
PubMed1988

Cerebral handicap in full-term neonates related to the mechanical forces of labour.

Sometimes the relationship between peripartum events and neonatal CNS injury is obvious: for example, following complete abruptio placentae or umbilical cord prolapse and occlusion with a delay of many minutes before delivery of the baby. These circumstances are, of course, rare in modern obstetrics. Usually, when a neonate develops neurological injury, a host of various potentially adverse peripartum factors are assumed to be the aetiology, but without definitive evidence. Among these latter factors are those we have focused on in this paper: the mechanical forces exerted on the fetal head during labour when the full-term fetus is in cephalic presentation. The mechanical events during the first stage of labour are reviewed, showing how uterine contractions result in cervical dilatation and descent and rotation of the fetal head. The consequences of these forces on the fetal intracranial pressure and blood flow are discussed: FHR remains normal up to a certain pressure threshold, above which decelerations occur. In other words, excessive pressures applied to the fetal head, either spontaneously (e.g. uterine tetany) or iatrogenically (e.g. traumatic forceps delivery or excessive fundal pressure) can increase fetal intracranial pressure to such a degree as to result in significant decreases in cerebral blood flow that are associated with fetal heart rate decelerations. Even when decelerations are simultaneous to contractions, decelerations cannot be considered as reflex and innocuous, as they are indeed associated with a decreasing cerebral blood flow. They must therefore be considered and evaluated in the management of labour. Cord compression and functional modifications of intervillous space by mechanical forces may further compromise the biological status of the fetus, leading to severe asphyxia. Neurological evaluation of the neonate within the first few days after delivery is currently the only way to provide the obstetricians with information on the possible consequences of an abnormal labour. The assessment of normality of the CNS in the neonate born at term, and its value in predicting late outcome are discussed. When abnormalities are detected after one or repeated assessments, abnormal neurological signs and symptoms are classified into three grades at the end of the first week. According to our data, a good correlation exists between this neonatal grading of cerebral dysfunction and late outcome. A careful evaluation of fetal head deformation, extensive caput succedaneum, and extensive retinal haemorrhages can help to interpret an abnormal labour retrospectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Asphyxia Neonatorum↗
PubMed1988

Prediction in very preterm infants of satisfactory neurodevelopmental progress at 12 months.

This study was performed to find out how well ultrasound brain-scanning and neurological examination of very preterm infants, together and separately, predicted normal neurodevelopmental progress at 12 months corrected age. 111 infants born at less than 33 weeks gestation were scanned at discharge from the neonatal unit, and neurological examinations were performed at a gestation-equivalent age at or near term. During the first year of life repeated neurological and developmental testing was carried out. At 12 months a diagnosis of normal progress or of major or minor neurodevelopmental disorders was made. 56 (50 per cent) infants with both a favourable ultrasound scan and normal neurological findings had a 98 per cent (90 to 99 per cent) probability of normal progress at 12 months, and a 100 per cent (93 to 100 per cent) probability of having no major disorder. Separately, ultrasound scanning and neurological examination were not such good predictors of normal outcome, although they selected larger groups of infants with high probabilities of progressing normally. Ultrasound brain-scanning and neurological examination can be used in combination to identify potentially normal preterm infants when they are discharged to their homes.

Central Nervous System↗
PubMed1988

[Cerebral Doppler technic during labor using signal monitoring at the level of the fetal scalp].

The purpose of modern obstetrics is to obtain tracers of the fetal cerebral risk during labor, enabling to deliver the child before cerebral ischemia occurs. Recording of the fetal heart and measurement of acid-base balance are remarkable tracers; however, a much better precision is desired to avoid unnecessary or too late caesarean sections. Blood velocity measurement by Döppler at the level of the vessels at the base of the fetal skull is technically possible during labor; this has been demonstrated in 8 fetuses. The major cerebral index D/S during labor is 0.40 +/- 0.04, i.e. slightly lower than the mean index measured at the cord (0.50 +/- 0.07). In case of decelerations, it decreases to a mean value of 0.22 +/- 0.02. These preliminary results permit to hope that long-term measurements with continuous Döppler, of the arterial fetal cerebral flow, provide a direct and accurate tracer of the risk of cerebral ischemia during labor.

Blood Flow Velocity↗
PubMed1986

[Discrimination of the mother tongue by newborn infants].

4-day-old infants from French-speaking families were examined for their ability to discriminate French from Russian sentences. The infants gave evidence of discrimination as well as preference for French.

Discrimination, Psychological↗
PubMed1978

The lecithin/sphingomyelin ratio in 132 insulin-dependent diabetic pregnancies.

A total of 228 determinations of L/S ratios were performed in 132 insulin-dependent diabetic pregnancies. A declining L/S ratio was observed in 6 per cent of the cases without adverse effects on the fetus. No significant difference in the percentage of mature L/S ratios by weeks of pregnancy was found in the different classes of diabetes. An immature L/S ratio was associated with a significant increase of low Apgar scores. At each stage of pregnancy, there was no significant difference in the percentage of mature L/S ratios according to the sex of the baby nor according to the presence or absence of polyhydramnios. Among the five infants with HMD two had a mature L/S ratio within 2 days of birth. This represents 3 per cent incidence of false-positive results. Despite this finding, we feel that the determination of L/S ratio is a useful advance in the management of diabetic pregnancies.

Amniotic Fluid↗