[Coma in full-term newborn infants following acute fetal distress: electro-clinical evolution]. / Coma après souffrance foetale aiguë chez le nouveau-né à terme: évolution électro-clinique.

Twenty full term infants who had birth asphyxia were studied. These infants were in a comatose state for 4 to 15 days and at least 3 EEG recordings were performed during this period. Six infants recovered without sequelae and in 2 cases there were minor abnormalities. In 7 cases there were major deficits (follow-up: 1 to 9 years) and 5 infants died within 15 days. Abnormal movements were observed in all the babies. Thirteen infants had EEG documented seizures (intermittent in 5 cases and status epilepticus in 8 cases). The prognosis was not correlated with the time of onset or duration of the coma, the time of onset or type of abnormal movements, nor with the presence of intermittent or continuous electrographic seizure activity. The initial tracing on the first day is the most significant prognostic factor. On subsequent days, an inactive EEG always indicated a poor prognosis. An improvement in the EEG on the 2nd on the 3rd day may not correlate with a favourable outcome since 3 such cases had a poor outcome. The clinical and EEG findings during therapy and the value of high levels of anticonvulsant therapy are discussed.

Seizures and electrical discharges in premature infants.

Electro-clinical seizures or electrical discharges are described in fifty premature infants divided in two groups: group A (GA twenty-six to thirty-two weeks) = thirty cases - group B (GA thirty-three to thirty-six wks) = twenty cases. In both groups, electrical discharges were shorter than electro-clinical seizures; during seizures ocular manifestations were frequent; bradycardia occurred only in group A. Discharges were associated with other abnormalities (absence of normal EEG pattern, presence of rolandic positive spikes) more frequently in group B than in group A; they occurred without clinical manifestations or coma in nine cases. After anticonvulsant therapy during EEG recording, disappearance of clinical manifestations was observed in four cases with persistence of electrical discharges. In two cases, complete depression of electric activity occurred, lasting less than fifteen minutes. Relatively favourable outcome (15%) was observed with discharges lasting less than five minutes, and, in six cases out of seven, with presence of normal inter-ictal EEG background. EEG helps in recognition of atypical seizures and in assessment of therapeutic effect and prognosis.

Positive rolandic sharp waves in neonatal EEG; types and significance.

We describe two types of electropositive rolandic sharp waves (PRS) in EEGs of premature infants with markedly different prognostic implications. Type A occurs singly and is clearly distinguished from the background activity; type B appears in bursts and blends somewhat with the background. Among neonates recorded at less than 35 weeks' conceptional age, 21% of those with type A only had normal neurological examinations or only minor sequelae at age 2 years. When type B appeared in the same tracing as type A, the percentage with normal examinations or minor sequelae at 2 years rose to 86%. Only 42% of those without type A or B had favourable 2 year evaluations. For those recorded at 35 weeks or later, normal or minor sequelae were found at 2 years as follows: type A only - 57%; type B only - 75%; types A and B - 92%; no positive rolandic sharp waves - 53%. We conclude that in both age groups type B PRS confer a relatively favourable prognosis and are more prognostically influential than type A. Patients with either type A or no PRS have less favourable outcomes than those with type B. Finally, although the majority of patients with intraventricular haemorrhage have type A PRS, IVH occurred in only 50% of patients with type A PRS when recorded before 35 weeks' conceptional age.

Expiratory patterns during sleep in normal full-term and premature neonates.

Airflow (V), tidal volume (TV), and EEG polygraphic recordings were performed in 30 normal full-term newborns (FTN) and in 10 premature newborns (PN). Besides the classical expiratory flow (CEF), a retarded expiratory flow (REF) was observed: a phase of slow flow ending with a sharp increase. REF was mostly encountered in quiet sleep (QS) in FTN. During REF, Te and Ttot became longer; Ti became shorter, with an increase in TV. In QS, sighs were more numerous in FTN with a high percentage of REF. Expiratory sudden short arrests of airflow (SSAA), less than or equal to 2 s, during expiration were more frequent in active sleep (AS) in FTN. REF may be due to some obstruction or to postinspiratory diaphragmatic activity; variations in functional capacity may also be involved.

[Convulsions in neonates. Clinical, electrographic, etiopathogenic and prognostic aspects]. / Convulsions du nouveau-ne. Aspects clinique, electrographique, etiopathogenique et pronostique.

121 cases of neonatal convulsions, including 79 cases of status epilepticus and 42 cases of isolated convulsions are studied. The great number of premature infants (40/121 newborns born before a gestational age of 37 weeks) must be pointed out. The clinical symptoms and EEG activity occurring during the first 24 hours following the onset of convulsions are analysed. Their descriptions confirm previous ones. Comparison of the populations of preterm and term infants demonstrates that the pre- and post-ictal neurological states are equally severe in both groups and that there is no difference between groups in the more or less precocious onset of convulsions. The value of the interictal EEG already described in status epilepticus of terms infants as predicting a poor prognosis, is confirmed. In addition, the very poor prognosis of an abnormal EEG pattern of the premature newborn, i.e. an EEG lacking any pattern corresponding to any gestational age, is demonstrated. Such EEGs of very poor prognosis have been detected in 46 cases. They reveal the degree of severity of the cerebral lesions, EEG abnormalities and cerebral lesions varying with gestational age. This study confirms the relatively mild severity of isolated convulsions as compared to status epilepticus. It demonstrates the severity of convulsions in premature newborns and of the electrographical discharges without simultaneous clinical event. The prognostic value of the absence or presence of a sleep cycle as early as the 24 hours following the onset of convulsions must be noted. Most of the neonatal convulsions are secondary to birth hypoxia or asphyxia and to meningo-encephalitis. In this study the small number of seizures due to metabolic factors is striking and contrasts with their great frequency in other series. The cause of the seizures is unknown in 12% of the cases; some of these cases of unknown origin correspond to the description of the 'convulsions of the 5th day'. The prognosis in full-term newborns has been improved greatly in recent years, probably due to improvement in obstetrical and neonatal intensive care.

The efficacy of caffeine in the treatment of recurrent idiopathic apnea in premature infants.

This prospective controlled study was aimed at evaluating the efficacy of caffeine in treating recurrent idiopathic apnea in the premature infant. Eighteen preterm infants (29 to 35 weeks' gestation) were studied. Recordings during the first 24 hours and on the fifth day of caffeine treatment showed a significant decrease of severe apnea (P less than 0.01) and of mild apnea (P less than 0.001) in the treated group (group 1) as compared with the control group (group II). No treatment of apnea other than caffeine was required in group I, whereas six neonates in group II had such severe and frequent apneic episodes for more than 48 hours that withholding additional treatment was believed to be unethical. No undesirable side effects of caffeine treatment were observed.

Respiratory frequencies of sleeping infants during the first months of life: correlations between values in different sleep states.

This study was carried out on 57 normal infants: 22 full-term newborns, examined in the hospital laboratory, and 35 2-18-wk-old infants, examined in two resident nurseries. Polygraphic records, including 1-3 complete sleep cycles, were performed during the morning. The tracings were analyzed by 20-sec epochs. Three to 10% of active sleep states (AS) and 0.8-4% of quiet sleep states (QS) included greater than or equal to 3 sec respiratory pauses. There were minimal, non-significant differences between respiratory frequencies (RF) in total and in no-pause tracings. Our results confirmed that RF was higher in AS in all ages, when compared with QS (P less than 0.02). During the transition (TS) from one to another well-defined sleep state, the respiratory rate showed an intermediate level (AS greater than TS greater than QS): the transition from AS to QS showed progressive slowing of RF, while the transition from QS to AS occurred abruptly, with sudden acceleration of RF. There was a significant slowing of RF during the couse of QS, while the RF in AS was more variable without significant differences between the beginning, the middle and the end of AS state. In this material RF was higher in 2-5-wk and 6-10-wk age groups, compared to newborns and to 11-18-wk-old infants. At all ages, there was a high degree of correlation (P less than 0.01) between RF found in different sleep states for given individuals: some infants breathed more rapidly and other more slowly in all sleep states. A review of the literature showed that the differences between normal RF.

[Assisted ventilation of newborn infants during sleep. Study of factors modifying adaptation to ventilation]. / Ventilation assistêe des nouveau-nês au cours du sommeil : recherche des facteurs modifiant l'adaptation à la ventilation.

During sleep, of ventilated newborns and young infants, spontaneous respiratory movements may occur, unrelated to the ventilation impulsions. The respiratory pattern is then classified as "active". On the contrary, the respiratory pattern is classified as "passive", when all respiratory movements are related to the ventilation insufflation. The factors which influence the dependence on the ventilator are studied in a group of 20 newborn and young infants. Prematurity, some biological data such as hyperoxia, hypocapnia, seem to favor this dependence. A rapid rate of ventilation (superior to 30/minute) is rarely related to an active respiration; a slow rate of ventilation seems favor this respiratory pattern. It is clear that adaptation to artificial ventilation is better during quiet sleep than during active sleep. Some physiopathological considerations are developed.

[Effects of therapy (diazepam, phenobarbital) on the E.E.G. in new-born babies during the first 24 hours of treatment (author's transl)]. / Essai d'évaluation des thérapeutiques (diazépam, phénobarbital) sur l'E.E.G. néonatal pendant les premières 24 H. du traitement.

The poor prognostic significance of inactive or paroxystic E.E.G. recordings in new-born babies appears to be well established (Monod et al., ibid., 1972, 32, 529-544). However, some cases have been described as having a favourable evolution even though such tracings had been proesent during the neonatal period. The authors studied, therefore, the effects of anticonvulsants (diazepam, phenobarbital) to see if they produced inactive or paroxystic tracings. A total of 19 new-born babies with convulsions of various etiologies were treated with phenobarbital and diazepam and recordings were made less than 24 hours after the beginning of treatment. Plasma levels were measured at the time of recording and varied from 3 to 26 micrograms/ml for phenobarbital and 0 to 2.75 micrograms/ml for diazepam. No paroxystic tracings were noted, but 2 inactive tracings were seen in infants who had been severely asphyxiated at birth, and in whom the plasma levels of the anticonvulants was found to be low. The injection of diazepam during the E.E.G. recording caused suppression of electrical discharges without notably altering the inter-seizure E.E.G. activity. The authors conclude that in the 19 cases studied the changes noted in the E.E.G. were related to the severity of the condition and were not secondary to therapy.

Distribution of skin potential responses according to states of sleep during the first months of life in human babies.

Sixty polygraphic records were made: 16 in newborns and 44 in infants aged from 1 to 25 weeks. 1. The stage of development of the central nervous system is better defined by criteria such as spindle maturation or skin potential response (SPR) distribution according to stages of sleep, then by chronological age; SPR prevalence during "quiet" sleep ("adult" distribution) is not apparent before 12 weeks of age. Classification according to the presence or absence of spindles during quiet sleep shows that: (a)in the group without spindles (1-6 weeks old), SPRs are more numerous during "active" sleep than in newborns; (b)in the group with sporadic spindles (3-11 weeks old) the SPR mean frequency is about the same in "active" and in "quiet" sleep; (c)SPR prevalence during "quiet" NREM sleep ("adult" distrbution) appears clearly in the group with spindles present throughout "quiet" sleep (10-25 weeks old). On the contrary, no relation was found between SPR distribution and the mode of onset of sleep. 2."Active" REM sleep seems to mature earlier than "quiet" NREM sleep. Our studies show that, in active sleep, SPRs increase significantly during the 1st month of life; after that, their frequency does not change any more. On the contrary, SPRs in quiet sleep increase throughout the whole period studied. This increase is also parallel to sleep spindle maturation.3. During transitional periods SPR frequency is between that of active and that of quiet sleep. There is no significant difference between SPR frequency during the first and the second sleep cycles.

Spatio-temporal organization of EEG in premature infants and full-term new-borns.

Inter- and intrahemispheric EEG relationships were studied as a function of maturation in new-born infants. The spatio-temporal organization of EEG activity obtained during the two stages of sleep described in new-born infants - quiet sleep and active sleep - was analysed in 9 full-term new-born infants and 5 prematures (6 records). EEGs were recorded through transverse parietal montage made up of six bipolar derivations. Two epochs of 1.5 min each - successively obtained in both stages of sleep - were digitized, filtered in three frequency bands (beta, theta and delta) and computer-processed according to two methods, factor analysis and rhythms averaging. 1. The following EEG characteristics were found in both groups: (a) Instability of frequency within each frequency band (beta, theta and delta). However, theta activity was the most stable of the three, especially in quiet sleep. (b) Variability of topographical organization (i.e., localization of maxima of potentials) from one moment to another in both stages of sleep and in the three frequency bands. In spite of this intra-individual variability some sort of "average structure" was found in all infants; it was characterized by usually lateral and often symmetrical positions of the maxima of potential on the two hemispheres. For the same infant this structure was the same in the three frequency bands. (c) Poor interhemispheric relationships under all conditions, as well as poor interregional links in one hemisphere. 2. Some EEG characteristics differentiated the two groups and thus seemed to be related to maturation. Compared to full-term newborns the premature group showed: better stability for all three activities, especially for beta activity; higher frequency and larger amplitude of beta activity; better inter- and intrahemispheric relationships; fewer differences related to sleep stages. These results are discussed in terms of organization of the underlying cortical generators. The authors suggest that the active areas would increase in number and in surface with maturation, whereas the links between these different separate areas would remain very poor in the human full-term new-borns as well on one hemisphere as across hemispheres. This last finding would argue against the hypothesis that the corpus callosum which, as is well known, matures early, plays an important role in the establishment of interhemispheric links.