Neonatal epilepsies: Clinical management

Neurodevelopmental outcome of neonatal seizures: A longitudinal study

INTRODUCTION

Neonatal seizures (NS) are the most common neurological emergency in the neonatal period. The International League Against Epilepsy (ILAE) proposed a new classification of NS based on semiology and highlighted the correlation between semiology and aetiology. However, neurodevelopmental outcomes have not been comprehensively evaluated based on this new classification.

AIMS

To evaluate neurodevelopmental outcomes and potential risk factors for severe outcomes in NS.

METHODS

Patients with video electroencephalogram confirmed NS were evaluated. Seizure aetiology, cerebral magnetic resonance imaging (MRI) data, background electroencephalograms data, general movements, and neurodevelopmental outcomes were analysed. Severe outcomes were one of the following: death, cerebral palsy, Griffiths developmental quotient <70, epilepsy, deafness, or blindness.

RESULTS

A total of 74 neonates were evaluated: 62 (83.8 %) with acute provoked NS (primarily hypoxic-ischaemic encephalopathy), and 12 (16.2 %) with neonatal-onset epilepsies (self-limited neonatal epilepsy, developmental and epileptic encephalopathy, cerebral malformations). Of these, 32 (43.2 %) had electrographic seizures, while 42 (56.7 %) had electroclinical seizures - 38 (90.5 %) were motor (42.1 % clonic) and 4 (9.5 %) were non-motor phenomena. Severe outcomes occurred in 33 of the 74 (44.6 %) participants. In multivariate analysis, neonatal-onset epilepsies (odds ratio [OR]: 1.3; 95 % confidence interval [CI]: 1.1-1.6), status epilepticus (OR: 5.4; 95 % CI: 1.5-19.9), and abnormal general movements (OR: 3.4; 95 % CI: 1.9-7.6) were associated with severe outcomes.

CONCLUSIONS

At present, hypoxic-ischaemic encephalopathy remains the most frequent aetiology of NS. The prognosis of neonatal-onset epilepsies was worse than that of acute provoked NS, and status epilepticus was the most predictive factor for adverse outcomes.

Sulfite Impairs Bioenergetics and Redox Status in Neonatal Rat Brain: Insights into the Early Neuropathophysiology of Isolated Sulfite Oxidase and Molybdenum Cofactor Deficiencies

Isolated sulfite oxidase (ISOD) and molybdenum cofactor (MoCD) deficiencies are genetic diseases biochemically characterized by the toxic accumulation of sulfite in the tissues of patients, including the brain. Neurological dysfunction and brain abnormalities are commonly observed soon after birth, and some patients also have neuropathological alterations in the prenatal period (in utero). Thus, we investigated the effects of sulfite on redox and mitochondrial homeostasis, as well as signaling proteins in the cerebral cortex of rat pups. One-day-old Wistar rats received an intracerebroventricular administration of sulfite (0.5 µmol/g) or vehicle and were euthanized 30 min after injection. Sulfite administration decreased glutathione levels and glutathione S-transferase activity, and increased heme oxygenase-1 content in vivo in the cerebral cortex. Sulfite also reduced the activities of succinate dehydrogenase, creatine kinase, and respiratory chain complexes II and II-III. Furthermore, sulfite increased the cortical content of ERK1/2 and p38. These findings suggest that redox imbalance and bioenergetic impairment induced by sulfite in the brain are pathomechanisms that may contribute to the neuropathology of newborns with ISOD and MoCD. Sulfite disturbs antioxidant defenses, bioenergetics, and signaling pathways in the cerebral cortex of neonatal rats. CII: complex II; CII-III: complex II-III; CK: creatine kinase; GST: glutathione S-transferase; HO-1: heme oxygenase-1; SDH: succinate dehydrogenase; SO32-: sulfite.

Clinical and Neurophysiologic Phenotypes in Neonates With BRAT1 Encephalopathy

BACKGROUND AND OBJECTIVES

BRAT1 encephalopathy is an ultra-rare autosomal recessive neonatal encephalopathy. We delineate the neonatal electroclinical phenotype at presentation and provide insights for early diagnosis.

METHODS

Through a multinational collaborative, we studied a cohort of neonates with encephalopathy associated with biallelic pathogenic variants in BRAT1 for whom detailed clinical, neurophysiologic, and neuroimaging information was available from the onset of symptoms. Neuropathologic changes were also analyzed.

RESULTS

We included 19 neonates. Most neonates were born at term (16/19) from nonconsanguineous parents. 15/19 (79%) were admitted soon after birth to a neonatal intensive care unit, exhibiting multifocal myoclonus, both spontaneous and exacerbated by stimulation. 7/19 (37%) had arthrogryposis at birth, and all except 1 progressively developed hypertonia in the first week of life. Multifocal myoclonus, which was present in all but 1 infant, was the most prominent manifestation and did not show any EEG correlate in 16/19 (84%). Video-EEG at onset was unremarkable in 14/19 (74%) infants, and 6 (33%) had initially been misdiagnosed with hyperekplexia. Multifocal seizures were observed at a median age of 14 days (range: 1-29). During the first months of life, all infants developed progressive encephalopathy, acquired microcephaly, prolonged bouts of apnea, and bradycardia, leading to cardiac arrest and death at a median age of 3.5 months (range: 20 days to 30 months). Only 7 infants (37%) received a definite diagnosis before death, at a median age of 34 days (range: 25-126), and almost two-thirds (12/19, 63%) were diagnosed 8 days to 12 years postmortem (median: 6.5 years). Neuropathology examination, performed in 3 patients, revealed severely delayed myelination and diffuse astrogliosis, sparing the upper cortical layers.

DISCUSSION

BRAT1 encephalopathy is a neonatal-onset, rapidly progressive neurologic disorder. Neonates are often misdiagnosed as having hyperekplexia, and many die undiagnosed. The key phenotypic features are multifocal myoclonus, an organized EEG, progressive, persistent, and diffuse hypertonia, and an evolution into refractory multifocal seizures, prolonged bouts of apnea, bradycardia, and early death. Early recognition of BRAT1 encephalopathy allows for prompt workup, appropriate management, and genetic counseling.

EEG in neonatal seizures: where to look and what to see

INTRODUCTION

Neonatal seizures are frequent and carry a detrimental prognostic outlook. Diagnosis is based on EEG confirmation. Classification has recently changed.

AREAS COVERED

We consulted original papers, book chapters, atlases, and reviews to provide a narrative overview on EEG characteristics of neonatal seizures. We searched PubMed, without time restrictions (last visited: 31 May 2022). Additional papers were extracted from the references list of selected papers. We describe the typical neonatal ictal EEG discharges morphology, location, and propagation, together with age-dependent features. Etiology-dependent electroclinical features, when identifiable, are presented for both acute symptomatic neonatal seizures and neonatal-onset epilepsies and developmental/epileptic encephalopathies. The few ictal variables known to predict long-term outcome have been discussed.

EXPERT OPINION

Multimodal neuromonitoring in critically ill newborns, high-density EEG, and functional neuroimaging might increase our insight into the neurophysiological bases of seizures in newborns. Increasing availability of long-term monitoring with conventional video-EEG and automated detection methods will allow clinicians and researchers to gather an ever expanding bulk of clinical and neurophysiological data to enhance accuracy with deep phenotyping. The latest classification proposal represents an input for critically revising our diagnostic abilities with respect to seizure definition, duration, and semiology, possibly further promoting clinical research.

Neonatal seizures treatment based on conventional multichannel EEG monitoring: an overview of therapeutic options

INTRODUCTION

Seizures are the main neurological emergency during the neonatal period and are mostly acute and focal. The prognosis mainly depends on the underlying etiology. Conventional multichannel video-electroencephalographic (cEEG) monitoring is the gold standard for diagnosis, but treatment remains a challenge.

AREAS COVERED

: This review, based on PubMed search over the last 4 decades, focuses on the current treatment options for neonatal seizures based on cEEG monitoring. There is still no consensus on seizure therapy, owing to poor scientific evidence. Traditionally, the first-line treatments are phenobarbital and phenytoin, followed by midazolam and lidocaine, but their efficacy is limited. Therefore, current evidence strongly suggests the use of alternative antiseizure medications. Randomized controlled trials of new drugs are ongoing.

EXPERT OPINION

: Therapy for neonatal seizures should be prompt and tailored, based on semeiology, mirror of the underlying cause, and cEEG features. Further research should focus on antiseizure medications that directly act on the etiopathogenetic mechanism responsible for seizures and are therefore more effective in seizure control.

Neurogenetic and Metabolic Mimics of Common Neonatal Neurological Disorders

Neurogenetic and metabolic diseases often present in the neonatal period, masquerading as other disorders, most commonly as neonatal encephalopathy and seizures. Advancements in our understanding of inborn errors of metabolism are leading to an increasing number of therapeutic options. Many of these treatments can improve long-term neurodevelopment and seizure control. However, the treatments are frequently condition-specific. A high index of suspicion is required for prompt identification and treatment. When suspected, simultaneous metabolic and molecular testing are recommended along with concurrent treatment.

Distinctive mechanisms of epilepsy-causing mutants discovered by measuring S4 movement in KCNQ2 channels

Neuronal KCNQ channels mediate the M-current, a key regulator of membrane excitability in the central and peripheral nervous systems. Mutations in KCNQ2 channels cause severe neurodevelopmental disorders, including epileptic encephalopathies. However, the impact that different mutations have on channel function remains poorly defined, largely because of our limited understanding of the voltage-sensing mechanisms that trigger channel gating. Here, we define the parameters of voltage sensor movements in wt-KCNQ2 and channels bearing epilepsy-associated mutations using cysteine accessibility and voltage clamp fluorometry (VCF). Cysteine modification reveals that a stretch of eight to nine amino acids in the S4 becomes exposed upon voltage sensing domain activation of KCNQ2 channels. VCF shows that the voltage dependence and the time course of S4 movement and channel opening/closing closely correlate. VCF reveals different mechanisms by which different epilepsy-associated mutations affect KCNQ2 channel voltage-dependent gating. This study provides insight into KCNQ2 channel function, which will aid in uncovering the mechanisms underlying channelopathies.

Clinical whole exome sequencing revealed de novo Heterozygous Stop-Gain and Missense variants in the STXBP1 gene associated with Epilepsy in Saudi Families

Intellectual disability and developmental encephalopathies are mostly linked with infant epilepsy. Epileptic encephalopathy is a term that is used to define association between developmental delay and epilepsy. Mutations in the STXBP1 (Syntaxin-binding protein 1) gene have been previously reported in association with multiple severe early epileptic encephalopathies along with many neurodevelopmental disorders. Among the disorders produced due to any mutations in the STXBP1 gene is developmental and epileptic encephalopathy 4 (OMIM: 612164), is an autosomal dominant neurologic disorder categorized by the onset of tonic seizures in early infancy (usually in the first months of life). In this article, we report two Saudi families one with de novo heterozygous stop-gain mutation c.364C > T and a novel missense c. 305C > A p.Ala102Glu in exon 5 of the STXBP1 gene (OMIM: 602926) lead to development of epileptic encephalopathy 4. The variants identified in the current study broadened the genetic spectrum of STXBP1 gene related with diseases, which will help to add in the literature and benefit to the studies addressing this disease in the future.

Genetic-cellular epilepsy: Clues to diagnosing newborns with neonatal seizures

OBJECTIVE

The aim of this study was to analyse clinical characteristics of newborns with genetic-cellular epilepsy (GCE) to compare them to those of newborns with seizures with other aetiologies and elucidate clues to the diagnosis of GCE.

METHODS

This retrospective single-centre study analysed data from an 8-year cohort of newborns with seizures from 2010-2017. Clinical, neurophysiological, laboratory, and imaging data and outcomes of children with GCE were compared to those of newborns with seizures with other aetiologies.

RESULTS

A total of 112 newborns (N = 68; 61% boys) were included. Hypoxic-ischaemic encephalopathy (N = 42; 29%) was the most common seizure aetiology; GCE (with pathogenic variants KCNQ2, KCNQ3, SCN2A, TBC1D24, CHD2, and STXBP) was diagnosed in 9 (6%). The group of newborns with GCE significantly differed from the group with seizures with other aetiologies in terms of family history of epilepsy (p = 0.000), neonatal epileptic status (NES) (p = 0.007), normal imaging studies (p = 0.000), and outcomes (p = 0.034), but did not differ regarding the type and age of seizure onset, number of antiepileptic drugs administered, and EEG results. Positive family history of epilepsy (p = 0.027), presence of NES (p = 0.041), and normal imaging studies (p = 0.002) were most indicative of the diagnosis of GCE. Probability of GCE with this combination was 0.92.

CONCLUSION

In a heterogenous group of newborns with seizures, a positive family history of epilepsy, presence of NES, and normal imaging studies were most indicative of the diagnosis of GCE.

Novel Therapeutics for Neonatal Seizures

Neonatal seizures are a common neurologic emergency for which therapies have not significantly changed in decades. Improvements in diagnosis and pathophysiologic understanding of the distinct features of acute symptomatic seizures and neonatal-onset epilepsies present exceptional opportunities for development of precision therapies with potential to improve outcomes. Herein, we discuss the pathophysiology of neonatal seizures and review the evidence for currently available treatment. We present emerging therapies in clinical and preclinical development for the treatment of acute symptomatic neonatal seizures. Lastly, we discuss the role of precision therapies for genetic neonatal-onset epilepsies and address barriers and goals for developing new therapies for clinical care.

Neonatal presentation of genetic epilepsies: Early differentiation from acute provoked seizures

OBJECTIVE

Although most seizures in neonates are due to acute brain injury, some represent the first sign of neonatal onset genetic epilepsies. Delay in recognition and lack of expert assessment of neonates with epilepsy may result in worse developmental outcomes. As in older children and adults, seizure semiology in neonates is an essential determinant in diagnosis. We aimed to establish whether seizure type at presentation in neonates can suggest a genetic etiology.

METHODS

We retrospectively analyzed the clinical and electroencephalographic (EEG) characteristics of seizures in neonates admitted in two Level IV neonatal intensive care units, diagnosed with genetic epilepsy, for whom a video-EEG recording at presentation was available for review, and compared them on a 1:2 ratio with neonates with seizures due to stroke or hypoxic-ischemic encephalopathy.

RESULTS

Twenty neonates with genetic epilepsy were identified and compared to 40 neonates with acute provoked seizures. Genetic epilepsies were associated with pathogenic variants in KCNQ2 (n = 12), KCNQ3 (n = 2), SCN2A (n = 2), KCNT1 (n = 1), PRRT2 (n = 1), and BRAT1 (n = 2). All neonates with genetic epilepsy had seizures with clinical correlates that were either tonic (18/20) or myoclonic (2/20). In contrast, 17 of 40 (42%) neonates with acute provoked seizures had electrographic only seizures, and the majority of the remainder had clonic seizures. Time to first seizure was longer in neonates with genetic epilepsies (median = 60 h of life) compared to neonates with acute provoked seizures (median = 15 h of life, p < .001). Sodium channel-blocking antiseizure medications were effective in 13 of 14 (92%) neonates with tonic seizures who were trialed at onset or during the course of the epilepsy.

SIGNIFICANCE

Seizure semiology is an easily accessible sign of genetic epilepsies in neonates. Early identification of the seizure type can prompt appropriate workup and treatment. Tonic seizures are associated with channelopathies and are often controlled by sodium channel-blocking antiseizure medications.

Loss of KCNQ2 or KCNQ3 Leads to Multifocal Time-Varying Activity in the Neonatal Forebrain Ex Vivo

Epileptic encephalopathies represent a group of disorders often characterized by refractory seizures, regression in cognitive development, and typically poor prognosis. Dysfunction of KCNQ2 and KCNQ3 channels has emerged as a major cause of neonatal epilepsy. However, our understanding of the cellular mechanisms that may both explain the origins of epilepsy and inform treatment strategies for KCNQ2 and KCNQ3 dysfunction is still lacking. Here, using mesoscale calcium imaging and pharmacology, we demonstrate that in mouse neonatal brain slices, conditional loss of Kcnq2 from forebrain excitatory neurons (Pyr:Kcnq2 mice) or constitutive deletion of Kcnq3 leads to sprawling hyperactivity across the neocortex. Surprisingly, the generation of time-varying hypersynchrony in slices from Pyr:Kcnq2 mice does not require fast synaptic transmission. This is in contrast to control littermates and constitutive Kcnq3 knock-out mice where activity is primarily driven by fast synaptic transmission in the neocortex. Unlike in the neocortex, hypersynchronous activity in the hippocampal formation from Kcnq2 conditional and Kcnq3 constitutive knock-out mice persists in the presence of synaptic transmission blockers. Thus, we propose that loss of KCNQ2 or KCNQ3 function differentially leads to network hyperactivity across the forebrain in a region-specific and macro-circuit-specific manner.

The Spectrum of KCNQ2- and KCNQ3-Related Epilepsy

KCNQ genes encode for a family of six transmembrane domains, single pore-loop, and K+ channel α-subunits that have a wide range of physiological correlates. In the brain, KCNQ2 and KCNQ3 heteromultimers are thought to underlie the M-current which is essential in raising the threshold for firing an action potential; mutations in these genes may cause several types of infantile epilepsies. KCNQ2-related disorders represent a continuum of overlapping neonatal epileptic phenotypes that range from KCNQ2 benign familial neonatal epilepsy (BFNE), a seizure disorder that occur in children who typically have a normal psychomotor development and are inherited as an autosomal dominant trait, to KCNQ2 early-onset epileptic encephalopathy (EOEE) as the result of a de novo pathogenic variant. KCNQ3-related disorders are rarer and include BFNE, benign familial infantile epilepsy and KCNQ3-related epileptic encephalopathy with intellectual disability with or without seizures and/or cortical visual impairment. For both KCNQ2- and KCNQ3-related disorders, it is possible to use several drugs for different classes of mutations (i.e., gain of function vs. loss of function), and usually their effects vary in relation to the clinical presentation and the phenotype of the patient. However, KCNQ2-EOEE patients have a worse response to treatment than KCNQ2-BFNE patients and usually become drug resistant with multiple daily seizures.

Recent Advances in the Diagnosis and Treatment of Neonatal Seizures

Seizures are the most common neurological emergency in the neonates, and this age group has the highest incidence of seizures compared with any other period of life. The author provides a narrative review of recent advances in the genetics of neonatal epilepsies, new neonatal seizure classification system, diagnostics, and treatment of neonatal seizures based on a comprehensive literature review (MEDLINE using PubMED and OvidSP vendors with appropriate keywords to incorporate recent evidence), personal practice, and experience. Knowledge regarding various systemic and postzygotic genetic mutations responsible for neonatal epilepsy has been exploded in recent times, as well as better delineation of clinical phenotypes associated with rare neonatal epilepsies. An International League Against Epilepsy task force on neonatal seizure has proposed a new neonatal seizure classification system and also evaluated the specificity of semiological features related to particular etiology. Although continuous video electroencephalogram (EEG) is the gold standard for monitoring neonatal seizures, amplitude-integrated EEGs have gained significant popularity in resource-limited settings. There is tremendous progress in the automated seizure detection algorithm, including the availability of a fully convolutional neural network using artificial machine learning (deep learning). There is a substantial need for ongoing research and clinical trials to understand optimal medication selection (first line, second line, and third line) for neonatal seizures, treatment duration of antiepileptic drugs after cessation of seizures, and strategies to improve neuromorbidities such as cerebral palsy, epilepsy, and developmental impairments. Although in recent times, levetiracetam use has been significantly increased for neonatal seizures, a multicenter, randomized, blinded, controlled phase IIb trial confirmed the superiority of phenobarbital over levetiracetam in the acute suppression of neonatal seizures. While there is no single best choice available for the management of neonatal seizures, institutional guidelines should be formed based on a consensus of local experts to mitigate wide variability in the treatment and to facilitate early diagnosis and treatment.

Neonatal Seizures Revisited

Seizures are the most common neurological disorder in newborns and are most prevalent in the neonatal period. They are mostly caused by severe disorders of the central nervous system (CNS). However, they can also be a sign of the immaturity of the infant’s brain, which is characterized by the presence of specific factors that increase excitation and reduce inhibition. The most common disorders which result in acute brain damage and can manifest as seizures in neonates include hypoxic-ischemic encephalopathy (HIE), ischemic stroke, intracranial hemorrhage, infections of the CNS as well as electrolyte and biochemical disturbances. The therapeutic management of neonates and the prognosis are different depending on the etiology of the disorders that cause seizures which can lead to death or disability. Therefore, establishing a prompt diagnosis and implementing appropriate treatment are significant, as they can limit adverse long-term effects and improve outcomes. In this review paper, we present the latest reports on the etiology, pathomechanism, clinical symptoms and guidelines for the management of neonates with acute symptomatic seizures.

The ILAE classification of seizures and the epilepsies: Modification for seizures in the neonate. Position paper by the ILAE Task Force on Neonatal Seizures

Seizures are the most common neurological emergency in the neonatal period and in contrast to those in infancy and childhood, are often provoked seizures with an acute cause and may be electrographic-only. Hence, neonatal seizures may not fit easily into classification schemes for seizures and epilepsies primarily developed for older children and adults. A Neonatal Seizures Task Force was established by the International League Against Epilepsy (ILAE) to develop a modification of the 2017 ILAE Classification of Seizures and Epilepsies, relevant to neonates. The neonatal classification framework emphasizes the role of electroencephalography (EEG) in the diagnosis of seizures in the neonate and includes a classification of seizure types relevant to this age group. The seizure type is determined by the predominant clinical feature. Many neonatal seizures are electrographic-only with no evident clinical features; therefore, these are included in the proposed classification. Clinical events without an EEG correlate are not included. Because seizures in the neonatal period have been shown to have a focal onset, a division into focal and generalized is unnecessary. Seizures can have a motor (automatisms, clonic, epileptic spasms, myoclonic, tonic), non-motor (autonomic, behavior arrest), or sequential presentation. The classification allows the user to choose the level of detail when classifying seizures in this age group.

Seizures in the neonate: A review of etiologies and outcomes

Neonatal seizures occur in their majority in close temporal relation to an acute brain injury or systemic insult, and are accordingly defined as acute symptomatic or provoked seizures. However less frequently, unprovoked seizures may also present in the neonatal period as secondary to structural brain abnormalities, thus corresponding to structural epilepsies, or to genetic conditions, thus corresponding to genetic epilepsies. Unprovoked neonatal seizures should be thus considered as the clinical manifestation of early onset structural or genetic epilepsies that often have the characteristics of early onset epileptic encephalopathies. In this review, we address the conundrum of neonatal seizures including acute symptomatic, remote symptomatic, provoked, and unprovoked seizures, evolving to post-neonatal epilepsies, and neonatal onset epilepsies. The different clinical scenarios involving neonatal seizures, each with their distinct post-neonatal evolution are presented. The structural and functional impact of neonatal seizures on brain development and the concept of secondary epileptogenesis, with or without a following latent period after the acute seizures, are addressed. Finally, we underline the need for an early differential diagnosis between an acute symptomatic seizure and an unprovoked seizure, since it is associated with fundamental differences in clinical evolution. These are crucial aspects for neonatal management, counselling and prognostication. In view of the above aspects, we provide an outlook on future strategies and potential lines of research in this field.

Epilepsy-Work-Up and Management in Children

Pediatric epilepsy is a highly variable condition due to age-related expression of syndromes that require specific diagnosis, evaluations, and treatments. Children with epilepsy differ from their adult counterparts in many important ways, mostly related to the age-related expression of specific epilepsy syndromes. This results in many important considerations related to the epilepsy diagnosis, classification, evaluations to determine an etiology, as well as treatment guidelines. A good understanding of these factors will help to establish an accurate epilepsy diagnosis, which in turn will guide appropriate testing and treatment decisions. In this way, patients will have improved seizure outcomes, and families will be educated appropriately and provided with the most accurate prognostic information available. The purpose of this article is to review the diagnosis, work-up, and management of pediatric epilepsy.

Electroencephalography in neonatal epilepsies

Neonatal epilepsies - neonatal seizures caused by remote symptomatic etiologies - are infrequent compared with those caused by acute symptomatic etiologies. The etiologies of neonatal epilepsies are classified into structural, genetic, and metabolic. Electroencephalography (EEG) and amplitude-integrated EEG (aEEG) are essential for the diagnosis and monitoring of neonatal epilepsies. Electroencephalography / aEEG findings may differ substantially among infants, even within infants with variants in a single gene. Unusual EEG/aEEG findings, such as downward seizure patterns on aEEG, can be found. Neonatal seizures are exclusively of focal onset. An International League Against Epilepsy task force proposed that the seizure type is typically determined by the predominant clinical feature and is classified into motor or non-motor presentations. Ictal EEG usually demonstrates a sudden, repetitive, evolving, and stereotyped activities with a minimum duration of 10 s. In epileptic spasms and myoclonic seizures, the cut-off point of 10 s cannot be applied. One must always be aware of electro-clinical dissociation in neonates suspected to have seizures. Amplitude-integrated EEG is also useful for the diagnosis and monitoring of neonatal epilepsies but aEEG cannot be recommended as the mainstay because of its relatively low sensitivity and specificity. At present, EEG findings are not pathognomonic, although some characteristic ictal or interictal EEG findings have been reported in several neonatal epilepsies. Deep learning will be expected to be introduced into EEG interpretation in near future. Objective EEG classification derived from deep learning may help to clarify EEG characteristics in some specific cases of neonatal epilepsy.

Targeted gene panel sequencing in early infantile onset developmental and epileptic encephalopathy

BACKGROUND

Early-onset developmental and epileptic encephalopathy (DEE) is characterized by repeated seizures beginning within 3 months of birth and severe interictal epileptiform discharge, including burst suppression. This study assessed the utility of targeted gene panel sequencing in the genetic diagnosis of this disease.

MATERIALS AND METHODS

Targeted gene panel sequencing was performed in 150 early infantile-onset DEE patients (≤3 months of age), and we extensively reviewed their clinical characteristics, including therapeutic efficacy, according to genotype.

RESULTS

Of the early infantile-onset DEE patients, 70 were neonatal-onset DEE and the other 80 patients began experiencing seizures from 1 to 3 months after birth. There were 11 different pathogenic or likely pathogenic variants among 34.7% (52/150) of patients with early infantile-onset DEE, in whom KCNQ2, STXBP1, CDKL5, and SCN1A were the major pathogenic variants. Among the neonatal-onset DEE patients, pathological genes were identified in 42.9% (30/70), indicating a significantly higher diagnostic yield than in 27.5% (22/80) of patients who experienced seizure onset 1 to 3 months after birth (p = 0.048). Among the neonatal-onset DEE group, variants in KCNQ2, STXBP1, and CDKL5 were detected at high frequencies, accounting for 66.7% (20/30) of the pathogenic or likely pathogenic variants found in this study.

CONCLUSION

Targeted gene panel sequencing demonstrated a high yield of pathogenic variants in the diagnosis of early-onset epileptic encephalopathy, especially in those with neonatal-onset DEE. Early diagnosis of early-onset epileptic encephalopathy may improve the prognosis of patients by earlier selection of appropriate treatment based on pathogenic variant.

EEG Monitoring of the Epileptic Newborn

PURPOSE OF REVIEW

Although differentiating neonatal-onset epilepsies from acute symptomatic neonatal seizures has been increasingly recognized as crucial, existing guidelines, and recommendations on EEG monitoring are mainly based on acute symptomatic seizures, especially secondary to hypoxic-ischemic encephalopathy. We aimed to narratively review current knowledge on neonatal-onset epilepsies of genetic, metabolic, and structural non-acquired origin, with special emphasis on EEG features and monitoring.

RECENT FINDINGS

A wide range of rare conditions are increasingly described, reducing undiagnosed cases. Although distinguishing features are identifiable in some, how to best monitor and detect less described etiologies is still an issue. A comprehensive approach considering onset, seizure evolution, ictal semiology, clinical, laboratory, EEG, and neuroimaging data is key to diagnosis. Phenotypic variability prevents precise recommendations, but a solid, consistent method moving from existing published guidelines helps in correctly assessing these newborns in order to provide better care, especially in view of expanding precision therapies.

Acute Symptomatic Seizures in Neonates

Seizures are an important sign of neurologic dysfunction in neonates, and they most often represent acute brain injury such as hypoxic-ischemic encephalopathy, stroke, or intracranial hemorrhage (acute symptomatic seizures). Clinical identification of seizures is not reliable since seizures in neonates often do not have an apparent clinical correlate; therefore, electroencephalography should be used to accurately diagnose and manage neonatal seizures. Seizures are refractory to initial loading doses of standard medications in >50% of cases. Since seizures are commonly associated with adverse acute and long-term outcomes, and the seizures themselves may result in additional brain injury, it is important to quickly recognize, diagnose, and treat seizures in neonates. Local practice pathways may optimize efficiency in assessment and treatment for affected newborns. Herein, we review the etiology, methods of diagnosis, treatment, and current knowledge gaps for neonatal seizures.

Genetic diagnosis of neonatal-onset seizures

Many seizures in neonates are due to early-onset epilepsy, which is often difficult to diagnose, especially to explore the causes. Recently, the development of next-generation sequencing (NGS) has led to the discovery of a large number of genes involved in epilepsy. This may improve prompt detection of early-onset epilepsy in neonates. This study aimed at analyzing the genotype-phenotype correlations in neonates with seizures in a bid to improve the understanding of genetic diagnosis of early-onset epilepsy. Clinical features and prognosis of 15 children who underwent genetic testing having had unexplained seizures from February 2016 to May 2018 in Children's Hospital of Chongqing Medical University were analyzed retrospectively. The salient findings were: poor response to stimulus and abnormal electroencephalogram (EEG) in the initial period were observed in the group with concomitant genetic abnormalities. Despite the recent progress in genetic technology, molecular diagnosis for neonatal-onset epilepsy can be challenging due to genetic and phenotypic heterogeneities. However, some genotypes are associated with specific clinical manifestations and EEG patterns. Therefore, in-depth understanding of genotype-phenotype correlations would be useful to clinicians managing neonates with early-onset seizures.

Why we urgently need improved seizure and epilepsy therapies for children and neonates

In contrast to epilepsy in adolescents and adults, neonatal seizures and early onset epilepsy poses unique challenges with significant repercussion for treatment choices. Most importantly, high seizure burden and epileptic encephalopathy are associated with developmental, behavioural and cognitive problems. The causes are multifactorial and include etiology, seizure burden, epileptic encephalopathy, but also antiseizure medication. In contrast to adults and older children only very few drugs have been licenced for infants and neonates, and after a long delay. Very recently, extrapolation of adult data has become possible as a path to speed up drug development for younger children but this is not necessarily possible for infants and neonates. With the advances in understanding the molecular basis of many epilepsies, targeted therapies become available, for example for KCNQ2 mutation related epilepsies, Dravet syndrome or tuberous sclerosis complex. Drug trials in neonates are particularly challenging because of their inconspicuous clinical presentation, the need for continuous EEG monitoring, high co-morbidity, and poor response to antiepileptic drugs. There is an urgent need for development of new drugs, evaluation of safety and efficacy of current antiseizure drugs, as well as for national policies and guidelines for the management of seizures and epilepsy in neonates and infants. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.

Influence of etiology on treatment choices for neonatal seizures: A survey among pediatric neurologists

BACKGROUND

A targeted treatment approach is increasingly promoted in epilepsy management.

AIM

To investigate if etiology (both established or initially presumed) influences antiepileptic drug choice of experts in neonatal seizures.

METHODS

An invitation to participate to a web-based questionnaire was sent to Italian pediatric neurologists affiliated to the Italian Society of Pediatric Neurology (SINP).

RESULTS

19 pediatric neurologists from different centers, all consultants of third level Neonatal Intensive Care Units (NICUs) answered. As first-line drug phenobarbital was the most common choice, it was used in 79% of cases of acute symptomatic seizures, in 63% of structural epilepsy, in 42% of genetic epilepsies. As second-line drug phenytoin was used by 58% in acute symptomatic seizures, 37% in structural epilepsy, 5% in genetic epilepsy. Pyridoxine/pyridoxalphosphate was much more used in genetic epilepsy (as first-line in 26%, as second-line in 37%) than in the other two conditions. Long-term conventional EEG monitoring was suggested as important to verify efficacy of drugs in controlling seizures by 84% of interviewed neurologists, but EEG was available around the clock in only 53% of their centers. 1 to 3-channel aEEG/EEG (commonly named CFM) was often used instead of conventional EEG monitoring.

CONCLUSION

This is the first survey looking at a targeted approach in treatment of neonatal seizures by pediatric neurologists consulted by NICUs. The treatment approach is similar to previous surveys in case of acute symptomatic seizures, but in case of other etiologies the choices are different, especially for the second-line option. Larger studies should address this topic.

Research on medication use in the neonatal intensive care unit

INTRODUCTION

Research on medication use aims at assessing how much of current pharmacotherapy is rational. In neonates, this is hampered by extensive off-label drug use and limited knowledge. Areas covered: We report on medication use research and have conducted a systematic review of observational studies on medication use to provide an updated overview on characteristics, objectives, methods, and patterns in hospitalized neonates. Moreover, a review on aspects of medication use for opioids, anti-epileptics, gastric acid-related disorders and respiratory stimulants with emphasis on trends and impact of interventions is presented, illustrating how research on medication use can contribute to improved neonatal pharmacotherapy and more focused research. Medication use reports describe patterns and provide signals on irrational use, benchmarking, or can guide research priorities. Moreover, this may generate information on how neonatal health topics and their pharmacotherapy are handled over time or across regions. Expert opinion: Research on medicine utilization is relevant, since it will inform us on aspects like trends, variability, or about the impact and pattern of implementation of guidelines in neonates. Further progress necessitates to merge datasets on medication use with clinical characteristics, and perinatal drug use remains an area in need of additional research.

Rational Use of Medicines in Neonates: Current Observations, Areas for Research and Perspectives

A focused reflection on rational medicines use in neonates is valuable and relevant, because indicators to assess rational medicines use are difficult to apply to neonates. Polypharmacy and exposure to antibiotics are common, while dosing regimens or clinical guidelines are only rarely supported by robust evidence in neonates. This is at least in part due to the extensive variability in pharmacokinetics and subsequent effects of medicines in neonates. Medicines utilization research informs us on trends, on between unit variability and on the impact of guideline implementation. We illustrate these aspects using data on drugs for gastroesophageal reflux, analgesics or anti-epileptic drugs. Areas for additional research are drug-related exposure during breastfeeding (exposure prediction) and how to assess safety (tools to assess seriousness, causality, and severity tailored to neonates) since both efficacy and safety determine rational drug use. To further improve rational medicines use, we need more data and tools to assess efficacy and safety in neonates. Moreover, we should facilitate access to such data, and explore strategies for effective implementation. This is because prescription practices are not only rational decisions, but also have psychosocial aspects that may guide clinicians to irrational practices, in part influenced by the psychosocial characteristics of this population.