Use of EEG in neonatal hypoxic-ischemic encephalopathy: A French survey of current practice and perspective for improving health care.

OBJECTIVES: Controlled therapeutic hypothermia (CTH) is a standard of care in the management of neonatal hypoxic-ischemic encephalopathy HIE in newborns after 36 weeks of gestational age (WGA) in France. The electroencephalogram (EEG) plays a major role in HIE diagnosis and follow-up. We conducted a French national survey on the current use of EEG in newborn undergoing CTH. METHODS: Between July and October 2021, an email survey was sent to the heads of the Neonatal intensive care units (NICUs) in metropolitan and overseas French departments and territories. RESULTS: Out of 67, 56 (83%) of NICUs responded. All of them performed CTH in children born after 36 WGA with clinical and biological criteria of moderate to severe HIE. 82% of the NICUs used conventional EEG (cEEG) before 6 h of life (H6), prior to CTH being performed, to inform decisions about its use. However, half of the 56 NICUs had limited access after regular working hours. 51 of the 56 centers (91%) used cEEG, either short-lasting or continuous monitoring during cooling, while 5 centers conducted only amplitude EEG (aEEG). Only 4 of 56 centers (7%) used cEEG systematically both prior to CTH and for continuous monitoring under CTH. DISCUSSION: The use of cEEG in the management of neonatal HIE was widespread in NICUs, but with significant disparities when considering 24-hour access. The introduction of a centralized neurophysiological on-call system grouping several NICUs would be of major interest for most centers which do not have the facility of EEG outside working hours.

The prognostic value of neonatal conventional-EEG monitoring in hypoxic-ischemic encephalopathy during therapeutic hypothermia.

AIM: To determine the prognostic value of conventional electroencephalography (EEG) monitoring in neonatal hypoxic-ischemic encephalopathy (HIE). METHOD: In this multicentre retrospective study, 95 full-term neonates (mean of 39.3wks gestational age [SD  1.4], 36 [38%] females, 59 [62%] males) with HIE (2013-2016) undergoing therapeutic hypothermia were divided between favourable or adverse outcomes. Background EEG activity (French classification scale: 0-1-2-3-4-5) and epileptic seizure burden (epileptic seizure scale: 0-1-2) were graded for seven 6-hour periods. Conventional EEG monitoring was investigated by principal component analysis (PCA), with clustering methods to extract prognostic biomarkers of development at 2 years and infant death. RESULTS: Eighty-one per cent of infants with an adverse outcome had a French classification scale equal to or greater than 3 after H48 (100% at H6-12). The H6-12 epileptic seizure scale was equal to or greater than 1 for 39%, increased to 52% at H30-36 and then remained equal to or greater than 1 for 39% after H48. Forty-five per cent of infants with a favourable outcome had a H6-12 French classification scale equal to or greater than 3, which dropped to 5% after H48; 13% had a H6-12 epileptic seizure scale equal to or greater than 1 but no seizures after H48. Clustering methods based on PCA showed the high efficiency (96%) of conventional EEG monitoring for outcome prediction and allowed the definition of three prognostic EEG biomarkers: H6-78 French classification scale mean, H6-78 French classification scale slope, and H30-78 epileptic seizure scale mean. INTERPRETATION: Early lability and recovery of physiological features is prognostic of a favourable outcome. Seizure onset from the second day should also be considered to accurately predict neurodevelopment in HIE and support the importance of conventional EEG monitoring in HIE in infants cooled with therapeutic hypothermia. WHAT THIS PAPER ADDS: Comprehensive analysis showed the high prognostic efficiency (96%) of conventional electroencephalography (EEG) monitoring. Prognostic EEG biomarkers consist of the grade of background EEG activity, its evolution, and the mean seizure burden. Persistent seizures (H48) without an improvement in background EEG activity were consistently associated with an adverse outcome.

Neurophysiological recordings improve the accuracy of the evaluation of the outcome in perinatal hypoxic ischemic encephalopathy.

OBJECTIVES: Our objective was to evaluate the potential additional value of electroencephalogram (EEG) and evoked potentials in neonates with hypoxic-ischemic encephalopathy to predict their disability at 1 and 2 years old. METHODS: 30 full-term infants after perinatal asphyxia who underwent therapeutic hypothermia were evaluated at 1 year and 2 years for disability using International Classification of Functioning, Disability and Health classification. Scores for EEG, sensory evoked potentials and brainstem auditory evoked potentials were evaluated after withdrawal of therapeutic hypothermia that lasted 72 h. A regression approach was investigated to build models allowing to distinguish neonates according to their disability at 1 and 2 years. Two models were built, the first by considering the clinical data and EEG before and after therapeutic hypothermia and the second by incorporating evoked potentials recording. RESULTS: Adding EEG and evoked potentials data after rewarming improved dramatically the accuracy of the model considering outcome at 1 and 2 years. INTERPRETATION: We propose to record systematically EEG and evoked potentials following rewarming to predict the outcome of neonates with hypoxic ischemic encephalopathy. Combination of altered evoked potentials with no improvement of EEG after rewarming appeared to be a robust criterion for a poor outcome.

The slow-flat-slow sequence in malignant vasovagal syncope.

We present the electroencephalographic and electrocardiographic tracing obtained in an 8-year old boy who experienced malignant vasovagal syncope during the recording. This tracing illustrates the highly specific "slow-flat-slow" sequence described in cases of syncope induced by severe cerebral hypoperfusion.

West Syndrome Is an Exceptional Presentation of Pyridoxine- and Pyridoxal Phosphate-Dependent Epilepsy: Data From a French Cohort and Review of the Literature.

Objective: To characterize the electro-clinical presentation of patients with pyridoxine-dependent epilepsy (PDE) and pyridoxal phosphate (PLP)-dependent epilepsy in order to determine whether some of them could be diagnosed as de novo West syndrome, i. e., West syndrome that starts after the age of 2 months without other types of seizures (focal seizures for instance) before the onset of epileptic spasms. Methods: We analyzed data from an unpublished cohort of 28 genetically confirmed cases of PDE with antiquitine (ATQ) deficiency and performed a review of the literature looking for description of West syndrome in patients with either PDE with ATQ deficiency or PLP-dependent epilepsy with Pyridox(am)ine phosphate oxidase (PNPO) deficiency. Results: Of the 28 cases from the ATQ deficiency French cohort, 5 had spasms. In four cases, spasms were associated with other types of seizures (myoclonus, focal seizures). In the last case, seizures started on the day of birth. None of these cases corresponded to de novo West syndrome. The review of the literature found only one case of PNPO deficiency presenting as de novo West syndrome and no case of ATQ deficiency. Significance: The presentation of PDE- and PLP-dependent epilepsy as de novo West syndrome is so exceptional that it probably does not justify a systematic trial of pyridoxine or PLP. We propose considering a therapeutic trial with these vitamins in West syndrome if spasms are associated with other seizure types or start before the age of 2 months.

Quantitative approach to early neonatal EEG visual analysis in hypoxic-ischemic encephalopathy severity: Bridging the gap between eyes and machine.

OBJECTIVES: To identify relevant quantitative parameters for early classification of neonatal hypoxic-ischemic encephalopathy (HIE) severity from conventional EEGs. METHODS: Ninety EEGs, recorded in full-term infants within 6 h of life after perinatal hypoxia, were visually classified according to the French EEG classification into three groups of increasing HIE severity. Physiologically significant EEG features (signal amplitude, continuity and frequency content) were automatically quantified using different parameters. The EEG parameters selection was based on their ability to reproduce the visual EEG classification. Post hoc analysis based on clinical outcome was performed. RESULTS: Six EEG parameters were selected, with overall EEG classification performances between 61% and 70%. All parameters differed significantly between group 3 (severe) and groups 1 (normal-mildly abnormal) and 2 (moderate) EEGs (p < 0.001). Amplitude and discontinuity parameters were different between the 3 groups (p < 0.01) and were also the best predictors of clinical outcome. Conversely, pH and lactate did not differ between groups. DISCUSSION: This study provides quantitative EEG parameters that are complementary to visual analysis as early markers of neonatal HIE severity. These parameters could be combined in a multiparametric algorithm to improve their classification performance. The absence of relationship between pH lactate and HIE severity reinforces the central role of early neonatal EEG.

Behavioral-state development and sleep-state differentiation during early ontogenesis.

Sleep is a key process in neurodevelopment and essential for the maturation of fundamental brain functions. Premature birth can disturb the initial steps of sleep maturation, which may contribute to the impairment of neurodevelopment. It is thus fundamental to understand the maturation of the various sleep states and the quality of cerebral function in each vigilance state, as well as the development of sleep cyclicity, in at-risk neonatal infants, particularly those born premature. The objective of this review is to provide a precise description of sleep states and cycles and their rhythmic organization in premature and term newborns according to their gestational age. Technical aspects of polysomnography, which requires a high level of expertise in neonates, are also described. Principles of the visual interpretation of polysomnography, including the simultaneous analysis of behavioral (spontaneous motricity and eye movements), polysomnographic parameters (electro-oculogram, electrocardiogram, respiration), and electroencephalography patterns are presented. The neurophysiology of sleep ontogenesis and its interaction with brain maturation are discussed, highlighting the crucial role of sleep states and their duration in premature newborns. In particular, the involvement of myoclonic twitches in functional connectivity in sensorimotor development is discussed. Indeed, sleep quality, determined by combined polysomnographic parameters, reflects either normal or pathological developmental processes during the neonatal period. The fundamental place of neurophysiological explorations in the early detection of sleep disorders is discussed, as well as their potential consequences on neurodevelopmental care to improve the prevention of neurodevelopmental impairment.

Technical recommendations and interpretation guidelines for electroencephalography for premature and full-term newborns.

Electroencephalography (EEG) of neonatal patients is amongst the most valuable diagnostic and prognostic tool. EEG recordings, acquired at the bedside of infants, evaluate brain function and the maturation of premature and extremely premature infants. Strict conditions of acquisition and interpretation must be respected to guarantee the quality of the EEG and ensure its safety for fragile children. This article provides guidance for EEG acquisition including: (1) the required equipment and devices, (2) the modalities of installation and asepsis precautions, and (3) the digital signal acquisition parameters to use during the recording. The fundamental role of a well-trained technician in supervising the EEG recording is emphasized. In parallel to the acquisition recommendations, we present a guideline for EEG interpretation and reporting. The successive steps of EEG interpretation, from reading the EEG to writing the report, are described. The complexity of the EEG signal in neonates makes artefact detection difficult. Thus, we provide an overview of certain characteristic artefacts and detail the methods for eliminating them.

Normal EEG during the neonatal period: maturational aspects from premature to full-term newborns.

Electroencephalography (EEG) is the reference tool for the analysis of brain function, reflecting normal and pathological neuronal network activity. During the neonatal period, EEG patterns evolve weekly, according to gestational age. The first analytical criteria for the various maturational stages and standardized neonatal EEG terminology were published by a group of French neurophysiologists training in Paris (France) in 1999. These criteria, defined from analog EEG, were completed in 2010 with digital EEG analysis. Since then, this work has continued, aided by the technical progress in EEG acquisition, the improvement of knowledge on the maturating processes of neuronal networks, and the evolution of critical care. In this review, we present an exhaustive and didactic overview of EEG characteristics from extremely premature to full-term infants. This update is based on the scientific literature, enhanced by the study of normal EEGs of extremely premature infants by our group of neurophysiologists. For educational purposes, particular attention has been paid to illustrations using new digital tools.

Correlation Between Clinical Signs and High-resolution Manometry Data in Children.

OBJECTIVES: High-resolution manometry (HRM) is the gold standard for diagnosis of esophageal motility disorders. However, clinical signs associated with these disorders are nonspecific, and it is difficult to correlate clinical signs with HRM data. The main objective of our study was to assess the positive predictive value (PPV) and negative predictive value (NPV) of each clinical sign, as well as their sensitivity and specificity in the diagnosis of esophageal motility disorders. METHODS: This is a bicentric retrospective cohort study based on HRM data collected between May 2012 and May 2016. The studied symptoms were weight loss, feeding difficulties, swallowing disorders, dysphagia, food blockages, vomiting, gastroesophageal reflux disease (GERD), belching, and respiratory symptoms. HRM data were analyzed according to the Chicago Classification (3.0). RESULTS: In total, 271 HRM data were analyzed, of which 90.4% showed abnormal results. HRM was well tolerated in 91% of the cases. The most common esophageal motility disorder was ineffective esophageal motility (38%). Weight loss was significantly associated (P = 0.003) with an abnormal HRM with a 96% PPV. CONCLUSIONS: With nonspecific clinical signs suggesting an esophageal motility disorder, weight loss was a predictive sign of abnormal HRM results. HRM was well tolerated in pediatric patients, and ineffective esophageal motility appears to be the most frequent motility disorder in our cohort, as already observed in adult patient studies.

Electroencephalographic characteristics of epileptic seizures in preterm neonates.

OBJECTIVE: Although seizures are more common in the neonatal period than in any other stage of childhood, those in preterm neonates are still poorly described. The aim of this study was to assess electro-clinical characteristics of seizures occurring before a corrected age of 40weeks in neonates born prematurely. METHOD: Retrospective analysis of EEG-documented seizures in neonates born prematurely. Seizures in a group of term neonates served as controls. RESULTS: Fifty-six prematurely born and 46 term born neonates were included. Median duration of seizures was 52s in preterm and 96s in term neonates. Seizures were focal or multifocal. In least mature neonates, they involved smaller regions of onset and remained localised. With increasing corrected age, propagation became more frequent. The electrographic pattern - maximal frequency of oscillation and the onset pattern also evolved with age. Electro-clinical seizures were observed in 25% of preterm versus 50% of term neonates; almost all electro-clinical seizures involved the central (motor) regions. CONCLUSION: Ictal EEG features undergo changes depending on corrected age. Most seizures are subclinical, thus EEG is essential for diagnosis. SIGNIFICANCE: Relating ictal EEG pattern to corrected age can improve diagnosis and ultimately management.

A patient with myoclonic epilepsy in infancy followed by myoclonic astatic epilepsy.

Myoclonic epilepsy in infancy (MEI) is a primary generalized epilepsy. According to the literature, the outcome of MEI is usually benign. Here we report a patient who developed myoclonic astatic epilepsy at age four, having been seizure free without antiepileptic drug treatment for 2 years after his recovery from MEI. At age four, a video-EEG-recording showed frequent head nodding (atonic seizures) and myoclonic astatic seizures associated with diffuse spikes or polyspikes and waves. The interictal EEG revealed frequent bursts of generalized 100-200 µV, 2-4 Hz spike-and-slow-wave complexes. Despite a general favorable outcome, more severe epilepsy syndromes may develop after MEI, and mental retardation is sometimes observed. Our case and the previous literature suggest that epilepsies following on from MEI often involve myoclonic seizures.

Clinical and manometric characteristics of Allgrove syndrome.

OBJECTIVE: The association of adrenocorticotropic hormone (ACTH) insensitivity with achalasia and alacrimia (Allgrove syndrome, 3A) constitutes a rare multisystem disorder. Its evolution is not well known. The aim of this study was to describe clinical and esophageal manometric characteristics and outcomes in Allgrove syndrome. PATIENTS AND METHODS: This multicenter retrospective study compared clinical and manometric characteristics at diagnosis and on follow-up of 9 children presenting with 3A (mean age at diagnosis 7.1 years) with those of 9 children with idiopathic achalasia (IA) (mean age at diagnosis 8.3 years). RESULTS: At the time of diagnosis, 3 children with 3A presented with no digestive or respiratory signs because they were identified during a family screening; 1 remained asymptomatic 8 years later. ACTH levels were high in patients with 3A. All of the patients with IA were symptomatic at diagnosis. No significant difference was observed when comparing any of the manometric parameters of the first esophageal manometry of 3A with those of IA. Seven children with 3A were operated on using the Heller procedure, completed by pneumatic esophageal dilation in 2 of these 7. One patient with 3A was treated only by nifedipine. Failure of treatment was observed in 3 children with 3A and 1 child with IA, partial success in 4 with 3A and 1 with IA, and total success in 2 with 3A and 7 with IA (P < 0.03). Control manometry showed that in the 3A group, partial success after surgery was always associated with abnormally low or normal lower esophageal sphincter (LES) pressure, whereas failure after surgery was associated with high LES pressure. CONCLUSIONS: Our data showed that 3A presented a more severe course than IA despite presymptomatic diagnosis in cases of family screening. The high LES pressure noted in some patients with 3A is suggestive of a peculiar pattern in 3A affecting the LES and the lower part of the esophagus.

Usefulness of video-EEG monitoring in children.

Video-EEG monitoring (v-EEG) was originally restricted to the evaluation for epilepsy surgery. It is now widely available and often utilized to clarify the nature of paroxysmal events or to identify the epileptic syndrome. It is important to define carefully the diagnostic value of this high-cost and time-consuming procedure. Few data on children are available. In this study, we have evaluated the utility of this procedure and the factors leading to a successful recording in children. We retrospectively reviewed 380 v-EEG done in 320 children. The rate of event detection was 59%. The v-EEG recorded a seizure in 40% (n=150), a non-epileptic event in 19% (n=73), and both seizure and non-epileptic events in 3% (n=11). Only 9% remained without diagnosis after v-EEG. The frequency of the usual events was the only factor contributing to a successful recording. This procedure confirmed the diagnosis of epilepsy in 43% of patients but excluded it in 25% of them. In children with epilepsy, the v-EEG allowed to define a new syndrome (30% of patients) or to improve clinical description and to identify the origin of the seizures (30%). The treatments were modified in 66% of patients following the v-EEG. Continuous video-EEG monitoring is an efficient and valuable procedure in the diagnosis and management of epilepsy and paroxysmal disorders in children.

Neonatal status epilepticus due to lamination disorder without significant cell death.

BACKGROUND: Malformations of the cerebral cortex may be associated with severe epilepsy and status epilepticus. It has been shown that status epilepticus models induce excitotoxic cell death. In humans, very few data are available. CASE AND RESULTS: We report a case of a multifocal disorder of the lamination diagnosed in a neonate, born at 30 weeks' gestation, who died from a refractory status epilepticus at two months and half. This abnormality was not detected by repeated MRI studies. Only microscopic investigations permitted to identify this disorder of the lamination. We found also little cell death or cell loss. DISCUSSION: Our report highlights the possible false negative results of MRI in a newborn. We can also discuss that immature human brain maybe less sensitive to neuronal injury than mature as described in animal models.

Infantile epileptic encephalopathy with late-onset spasms: report of 19 patients.

PURPOSE: Late-onset spasms (LOS) are epileptic spasms starting after the first year of life. Our aim was to assess the electroclinical features and the follow-up of the patients with this particular type of epileptic seizure. METHODS: We retrospectively included all patients with LOS confirmed by electroencephalography between 1989 and 2008. Clinical and electroencephalographic findings at diagnosis and during follow-up were collected. The Vineland scale was used to evaluate the neuropsychological outcome. RESULTS: We report 19 patients with LOS of 240 patients with recorded epileptic spasms. Eighteen patients had an epileptic encephalopathy with late-onset spasms. The ictal electroencephalography (EEG) showed a focal or generalized discharge of triphasic slow-waves, slow-spikes, or slow spikes-waves with fast activities. The interictal EEG usually showed focal or generalized slow-waves or slow spikes-waves without hypsarhythmia. LOS were controlled in only six patients. Three developed typical Lennox-Gastaut syndrome and 10 had a severe epileptic encephalopathy. Neuropsychological outcome was evaluated in 15 patients with the Vineland scale. Cognitive functions were normal in only one patient, whereas severe cognitive delay was observed in 12 of 15. CONCLUSION: Epileptic spasms may appear after the age of one. They are more frequently observed in patients with epileptic encephalopathy. In few patients this type of seizure was observed before the patients fulfill Lennox-Gastaut syndrome criteria. In one patient, we diagnosed a focal epilepsy with seizures occurring in cluster. When LOS are related to an epileptic encephalopathy, this epileptic syndrome seems to be linked to refractory epilepsy and severe cognitive outcome unrelated to the etiology.

Outcome of functional constipation in childhood: a 10-year follow-up study.

OBJECTIVES: To assess the outcome of patients presenting with functional constipation in childhood during a 10-year period and to determine any risk factors for developing persistent constipation throughout adolescence and adulthood. PATIENTS AND METHODS: 72 children (mean age 4 years; 40 boys) referred for constipation were included in a longitudinal set of observations. Initial workup included segmental colonic transit time and anorectal manometry; 45 of the 72 patients could be reevaluated 10 to 12 years later. RESULTS: 21 of 45 patients (46%; 95% confidence interval 29% to 67%) remained constipated at follow-up. Encopresis and recurrent abdominal pain were present in 25% and 56% of patients, respectively. Patients with anorectal dyssynergia remained more frequently constipated at follow-up than the others: 61% versus 29% (P < .05). CONCLUSION: Almost 50% of patients presenting with constipation during childhood remained constipated on long-term follow-up. Anorectal dyssynergia is associated with a worse prognosis.