[Electroencephalography of the premature and term newborn. Maturational aspects and glossary]. / Electroencéphalographie du nouveau-né prématuré et à terme. Aspects maturatifs et glossaire.

From the first publication of C. Dreyfus-Brisac and N. Monod, a strong tradition combined with tremendous development of neonatal EEG has taken place in France. After 3 years of collaborative work, 12 clinical neurophysiologists trained at the Port-Royal medical school in Paris detail in this paper the currently available neonatal EEG recording techniques. They have synthesized the criteria of maturational state analysis and have defined the normal and pathological neonatal EEG patterns, including descriptions already present in the French as well as the English literature. In this review one may find a complete description of neonatal EEG patterns according to the states of vigilance and to gestational age. Furthermore, definitions of all normal and pathological patterns are provided in a glossary. Both chapters are illustrated by numerous figures. This detailed terminology in neonatal EEG should allow a better homogeneity in EEG reports, and could lead to multicentric studies on normal, unusual or pathological patterns, according to etiology. Although based on analogic EEG data, this work can equally be applied to digitized EEG tracings.

[Localized neonatal convulsions and cerebral arterial infarction]. / Convulsions néonatales focalisées et infarctus artériel cérébral.

BACKGROUND: Stroke is a rare cause of neonatal seizures. CASE REPORTS: During a 5-year period, eight full-term infants were admitted to hospital for seizures due to a stroke. Seizures began shortly after birth and were always one-sided. Early CT scans showed cerebral infarctions. Motor disabilities such as hemiparesis were found in three out of seven cases; language difficulties were observed in the same proportion; however all the children had not reached school age. CONCLUSION: Neonatal localized seizures may be symptomatic of a stroke and therefore justify a computerized tomography (CT) scan. Motor and cognitive sequelae require early management.

Normal and pathological changes in alpha rhythms.

Normal alpha rhythm begins to appear at three months. It was possible to observe successively, the rhythmicity, visual reactivity, occipital topography, and at the end of the first year, the first bursts of 7-8 Hz waves. Evolution of alpha was not linear with the age. Alpha frequency acceleration was important before the age of 11 years. In adults it decreased from 20 to 55, then there was a tendency to increase with aging. Amplitude was highest at 11-12 years, then its tendency was to decrease until 40, and to increase later. In pathology, for instance, alpha could be observed too early in newborn and infants with malformations, in children, in some psychiatric diseases, in adults and old people, alpha was replaced by theta waves in dementia: it seemed to be a very reliable sign, at the beginning of the disease.

Prognostic value of neonatal electroencephalography in premature newborns less than 33 weeks of gestational age.

In a prospective study of 417 premature neonates born before 33 weeks' gestational age, neonatal tracings were reviewed to evaluate the use of EEG in prognosis of neurological injuries. The population was divided into two groups: Group 1, infants who died before the age of 1, and Group 2, survivors in which two categories of motor development were considered. Category A, were abnormal, and Category B, were always normal. Positive rolandic sharp waves (PRSW), which reflect white matter injury, occurred equally in both groups, indicating a similar incidence of white matter damage in Groups 1 and 2. In Group 2, there was a significant correlation of PRSW with developmental motor sequelae (Category A). A frequency of PRSW above 2/min (suggesting more severe periventricular white matter injury) and seizures were significantly more prevalent in Group 1 than in Group 2 and in Category A of Group 2 than in Category B. Background abnormalities occurred equally in both subgroups of extremely premature infants (< or = 28 weeks' gestation) they were significantly more numerous in the subgroup of very premature infants (between 28 and 33 weeks' gestation) who died, than in the subgroup of very premature infants who survived. This study shows the potential utility of using neonatal EEG in association with transfontanellar ultrasonography in anticipating the neurological development of very (> 28 weeks' gestation) and extremely (< or = 28 weeks' gestation) premature newborns.

Effects of repeated administration of zolpidem on sleep, diurnal and nocturnal respiratory function, vigilance, and physical performance in patients with COPD.

STUDY OBJECTIVE: To assess the effects of repeated 10-mg oral doses of zolpidem on diurnal and nocturnal respiratory function, as well as on diurnal vigilance and physical performance in COPD patients with disordered sleep. DESIGN: Prospective single-blind placebo-controlled clinical study. SETTING: Outpatients of a respiratory medicine department. PATIENTS AND METHODS: Patients with stable COPD were enrolled for 10 days (D0 to D10), ie, 9 consecutive nights (N1 to N9). They received placebo on N1 and N9 and zolpidem, 10 mg, from N2 to N8. MEASUREMENTS: The following parameters were measured: nocturnal polysomnographic recordings with respiratory signals and arterial blood gas values on retiring and awakening on N0, N1, N2, N8, and N9; subjective evaluation of the quality of sleep and of diurnal vigilance by visual analog scales every day from D0 to D10; pulmonary function test, central control of breathing, and walking test on D0 and D9; biological laboratory tests and theophylline level on D0 and D8. RESULTS: Ten COPD patients (PaO2 = 72.7 +/- 7.6 mm Hg; PaCO2 = 47.7 +/- 5.4 mm Hg; FEV1 = 0.84 +/- 0.3 L; FEV1/vital capacity = 42.5 +/- 12.3%), 56.8 +/- 8.3 years old, were studied. Compared with placebo, no significant change was found for the various sleep architecture parameters, except an increase in the duration of stage 2 during the D8/N8 night (p < 0.05). In contrast, the autoevaluation score for the quality of sleep was significantly improved during the D6/N6 night relative to that with placebo (p < 0.05), with no change in the other subjective criteria. No variable of the nocturnal respiratory parameters, pulmonary function test, central control of breathing, and physical performance was altered by zolpidem. Arterial blood gas values on awakening were not altered. Clinical and biological tolerance of zolpidem was correct with no significant variation of the theophylline level. CONCLUSION: This study shows that repeated 10-mg oral doses of zolpidem during 8 days does not impair nocturnal respiratory and sleep architecture parameters or diurnal pulmonary function tests, central control of breathing, and physical performances in patients with stable COPD.

[Actimetry: simplified analysis of wake-sleep rhythms in the newborn. Preliminary results]. / Actimétrie: analyse simplifiée des rythmes veille-sommeil chez le nouveau-né. Résultats préliminaires.

Actimetry in newborns is relevant if two actimeters are placed, one on each ankle. This study has been conducted on nine normal three days old newborns. It has shown an indisputable link between the lack of activity and the observed sleep during the night that was missing during the day. The longest period of wake was recorded during the day and the longest period of sleep or inactivity was during the night. This study has confirmed the existence of an ultradian rhythm of quiet sleep and wake. It is also possible that a beginning of a circadian rest-activity rhythm exists already in the neonatal period, that is still discussed in the literature.

[Topographic analysis of interictal spikes in the presurgical evaluation of severe partial epilepsy]. / Analyse topographique des pointes intercritiques dans l'évaluation préchirurgicale des épilepsies partielles sévères.

Fifteen patients have been examined: ten suffered from partial epilepsy of presumed mesiotemporal origin (group 1) and the other five presented partial epilepsy with non mesiotemporal or extra temporal epileptic focus (group 2). But in all cases, visual inspection of EEG traces demonstrated focally temporal interictal spikes. We have studied the spike voltage distributions and their corresponding scalp current density fields. Spike voltage topography revealed no significant difference between the two groups. Conversely SCD fields pointed out different specific characteristics according to the group. In the group 1, the gradient was always transversal, between the anterior temporal and the homolateral pre-frontal zones whereas in the group 2 it was antro-posterior in four patients. A more complete analysis of interictal spike by SCD representation should be useful in présurgical evaluation of patients with focal epilepsy.

[Automatic analysis of sleep-wake states during the first year of life]. / Apport de l'analyse automatique des états veille-sommeil au cours de la première année de la vie.

Automatic analysis on infant sleep tracing was first considered as an aid to the rapid construction of hypnograms. It has long been thought more complicated than in adults, because of the significant changes in electrogenesis during the first year of life, resulting in difficulty to adapt to the criteria of Rechtschaffen and Kales (1968), even if modified, or to those of Anders et al (1971). In fact, these studies have shown that automatic analysis of sleep EEG tracings permit an easier analysis of the changes in electrogenesis according to subject age, sleep stage and time of night. Moreover, automatic analysis of parameters which change with the sleep-wake stages shows the continuity of these changes, and therefore the somewhat arbitrary nature of conventional hypnogram classification. The mathematical treatment of this information facilitates their visualisation, and permits a better analysis of circadian and ultradian variations that could scarcely be formalized by classical hypnogram analysis. In the study of maturation occurring during the first months of life, automatic signal processing will require adaptation that will lead to new forms of reasoning.

[Electroencephalography and normal aging]. / Electroencéphalographie et vieillissement normal.

It is a widely accepted that normal ageing hardly modifies basal rythms: alpha frequency remains occipital, symmetrical, and reactive when eyes are opened. There is probably a frequency decrease, but this is hard to determine individually in the absence of longitudinal studies. In any event, alpha frequency never drops below 9 cycles per second until after 80 years of age. Localized and mostly left-sided temporal abnormalities in normal subjects have been noted several times in the literature. However, these pose the problem of early detection of brain damage in patients with hypertension, heart of pulmonary disease. Therefore, further EEG studies on normal and pathological cerebral ageing should investigate clinically well-defined populations.

[EEG in elderly cardiac patients without cerebral lesions]. / Vieillissement EEG chez des sujets cardiaques sans lésion cérébrale.

Ageing is known to be accelerated by risk-factors. The continuity between normal and pathological ageing is still quite disputed. Concerning cerebral ageing, the use of statistical methods on electroencephalographic (EEG) parameters appeared to be interesting. In this study, three different groups of elderly subjects were examined by EEG: normal subjects without neurological nor cardiac disease, subjects with Alzheimer-dementia (AD) and cardiac patients without cerebral clinical signs. Stepwise discriminant analysis showed that EEG-parameters discriminating normal subjects from cardiac patients were different from those discriminating AD-patients from normal. Furthermore, AD-patients could be well-discriminated from elderly cardiac patients.

[An aid to the electrophysiological diagnosis of diabetic peripheral neuropathy]. / Aide au diagnostic électrophysiologique de la neuropathie périphérique diabétique.

The electrophysiological diagnosis of peripheral neuropathy in diabetics becomes increasingly difficult with the increase in number of parameters measured. We have examined 102 subjects: 60 diabetics, 32 control subjects and 10 with impaired glucose tolerance. From the 37 recorded parameters during 8 examinations, a linear discriminant analysis allowed us to separate the 19 diabetics with clinical neuropathy and the control subjects with only 5 parameters, with a good concordance (96%): the motor conduction velocities (MCV) of the peroneal and median nerves, the amplitude of the action potential (AP) of the sural nerve, the Hmax/Mmax ratio and the M latency of the Hoffman reflex. These parameters, weighted with a coefficient, constitute a score of discrimination. This score has been tested by the Jackknife method on the same sample (94% of well-classified patients), then validated on the other patients. Thus we propose a method to aid the diagnosis of diabetic peripheral neuropathy, without the arbitrary character of the classical single parameter method, and allowing easy repetition.

[Positive rolandic sharp waves, periventricular ischemia and neurologic outcome. Prospective study in 66 premature infants]. / Pointes positives rolandiques, ischémie périventriculaire et devenir neurologique. Etude prospective chez 66 prématurés.

A prospective study concerning 66 prematures born after 32 weeks of gestation showed a 33% incidence of positive rolandic sharp waves (PRSW) on EEGs. The results showed a good sensitivity (Se = 95%) and specificity (Sp = 93%) of PRSW for the diagnosis of periventricular ischemia with motor sequelae. A PRSW frequency higher than one per minute and its persistence on 2 successive EEGs constitutes an indication of severity of the lesions. This study emphasizes the necessity of several EEG recordings in prematures.

Choice of the reference for EEG mapping in the newborn: an initial comparison of common nose reference, average and source derivation.

The instantaneous amplitude of different EEG patterns found in a 36 week newborn baby were mapped by isopotential display, using 3 different references. We found that in certain cases, the nose reference recalculated average and source derivations give the same results. If the different EEG activities on the skull have too an high amplitude, and are not in phase opposition, the average reference differs from the zero potential of the common reference. In this case, the nose may be a better reference. However, it is possible that under other conditions high amplitude activity contaminates the nose, rendering the other references as better choices. From these preliminary results, we recommend the simultaneous display of maps obtained with the different references, and the comparison of the maps with the tracings for topographic studies in babies. It is absolutely necessary to record at least two polygraphic derivations to be able to recognize the sleep stages in which the analyses were performed. The eyes movement lead lets us to see if the EEG activity contaminates the face with multiple displays. It is then possible to decide which reference system is most appropriate.

[Gastroesophageal reflux during++ sleep in obese patients]. / Reflux gastro-oesophagien pendant le sommeil chez l'obèse.

Evidence of relationship between gastrooesophageal reflux (GER) and obstructive apneas in some near-miss children, led us to investigate its possibility in adults. Our purpose was to look for 1) sleep stages of GER occurrence, and 2) the possible chronological link between sleep apneas and GER. Eight obese patients were investigated. Esophageal pHmetry was carried out on two consecutive nights. On the second night, sleep polygraphy was performed including EEG, EOG, EMG, nasal and buccal flows, thoracic and abdominal motions. Esophageal pHmetry was analyzed between the onset of sleep and the definite waking. Fifteen GER episodes occurred in 4 of the 8 patients. Fourteen of them occurred during wakefulness or transient arousals. Only 1 occurred during REM sleep. Four hundred forty five apneas were recorded in 7 patients. None of the obstructive apneas, or mixed apneas followed or preceded a GER. In 1 patient, 2 central apneas succeeded to GER during REM sleep. We conclude that 1) GER, as in healthy subjects, occurs essentially during wakefulness or transient arousals; 2) in these patients, we did not establish a causal relationship between GER and obstructive apneas nor between apneas and GER.

Sleep organization in children at risk for sudden infant death syndrome.

The organization of sleep was studied in four groups of 6-month-old babies: monitored near-miss babies (NM), monitored siblings (HR), nonmonitored siblings (LR), and siblings considered at low risk but monitored because of marked parental anxiety (PA). It was studied using the method of cumulated occurrences and orthogonal polynomial fitting introduced for the analysis of sleep by Gaillard and Martinoli in 1976. No monitoring effect was found. We also found no difference between the groups when the usual sleep scores were used. However, differences were found with the polynomial adjustment method: there was more quiet sleep stage 3 in NM than in any other group. There was less waking state and more paradoxical sleep at the end of the night in PA and NM than in HR or LR babies. This suggests that the differences may not be related so much to real risk as to parental comportment.

[Peripheral arterial catheterization in neonates and infants. Remote study of the arterial permeability by the Doppler effect]. / Cathétérisme artériel périphérique chez le nouveau-né et le petit nourrisson. Etude à distance de la perméabilité artérielle par effet Doppler.

Nineteen peripheral arteries were examined by Doppler US 1 month to 2 years after their catheterization. Two of them were completely obstructed and 4 showed signs of arterial stenosis. No functional repercussion was observed. This minor risk seems low as compared to the advantages of the technique.

[Study of basal rhythms in normal and pathologic subjects by EEG mapping]. / Etude des rythmes de base chez le sujet normal et pathologique par la cartographie EEG.

The topography of basic EEG rhythms brings a new dimension to our understanding of normal and pathologic electrogenesis in the brain. But our experience has shown that it is valuable to make use of the numeric spectral data in order to best decide which rhythms should be mapped. This study demonstrates that quantification of basic EEG rhythms is valuable, not only for beta activity in pharmacology or as an aid for the diagnosis and localization of epilepsy (as has been reported in the literature), but for the other rhythms as well. Our experience to date suggests that EEG rhythms be divided into two major groups: 1) occipital rhythms of extremely variable power which have a peak frequency equal to or greater than 8 Hz and which react to eye opening and 2) parietal-central rhythms which have a frequency equal to or less than 7.5 Hz and which are unreactive to eye opening. Alteration of these characteristics may occur as a result of widely different types of pathology but are usually not visible in the traditional EEG.

[Retrospective study of 25 sudden death in 25 infants hospitalized during the neonatal period]. / Etude rétrospective de 25 nourrissons décédés de mort subite et hospitalisés en période néo-natale.

During a 6 years period, 25 newborns admitted to a neonatal intensive care unit died suddenly in the first year of life. The risk of sudden death in this specific population is 5% and reaches 7.4% in the low birth weight population (less than or equal to 2,500 g). In 12 infants, the sudden death was partially explained; in 7 infants, the sudden death remained unexplained on the basis of clinical and necropsic findings; in 6 infants, the clinical data did not justify the sudden death but necropsies were not performed. A comparison with matched living control infants showed that there was a significant increase of minor malformations of the branchial arch system and that in the sudden infant death group, threatening premature labour was more frequent during the mothers' pregnancies.

Positive rolandic sharp waves and periventricular leukomalacia in the newborn.

Four cases of periventricular ischemia without hemorrhage in premature infants are described in which positive rolandic sharp waves (PRSW) were predominant in the electroencephalogram (EEG). These findings suggest the relationship of PRSW to periventricular ischemia rather than to intraventricular hemorrhage, per se, as has been considered by most investigations in the past. These PRSW can provide an early indication of periventricular leukomalacia.