Crisis neonatales y evolución a epilepsia en un hospital de tercer nivel / Neonatal seizures and progression to epilepsy in a tertiary hospital

Introducción Las convulsiones neonatales son un reto diagnóstico, dada la inmadurez del recién nacido. La mayoría son secundarias a un evento agudo. Un pequeño porcentaje constituye el inicio de una epilepsia. Objetivos Analizar a los neonatos ingresados en un hospital de tercer nivel con diagnóstico de crisis entre noviembre de 2009 y mayo de 2021, y su evolución posterior a epilepsia. Material y métodos. Se ha realizado un estudio observacional retrospectivo utilizando la base de datos del hospital. Se ha recogido la información de los neonatos con diagnóstico en el alta de ‘convulsiones’ o ‘encefalopatía hipóxico-isquémica moderada o grave’. Se analizaron distintas variables: etiología de las crisis, tipo, persistencia temporal, tratamiento y correlato electroclínico. Resultados De 165 pacientes, 55 presentaron crisis neonatales. En cuanto a la etiología, 43 pacientes (78%) tuvieron crisis secundarias a un evento agudo, de las cuales 19 (34%) fueron encefalopatías hipóxico-isquémicas, y 22 (40%), otras alteraciones agudas. En seis (11%) se encontró alteración genética. Trece pacientes (24%) evolucionaron a una epilepsia posterior, de los cuales siete presentaron una epilepsia sintomática, con un período de latencia tras el evento agudo en dos pacientes. Seis pacientes tuvieron epilepsia neonatal con crisis no provocadas. Veintidós (62%) mostraron correlato electroclínico. El 100% de las crisis confirmadas fueron focales. Todas las crisis se trataron. El fármaco de elección fue el fenobarbital. Conclusiones El diagnóstico de convulsiones neonatales requiere una alta sospecha clínica y una confirmación electroclínica. La mayoría tiene evolución favorable, pero un porcentaje constituye el inicio de una epilepsia, cuya identificación determinará su manejo terapéutico. (AU)

INTRODUCTION Given the immaturity of the newborn, neonatal seizures are a diagnostic challenge. Most of them are secondary to an acute event. A small percentage constitute the onset of epilepsy. AIMS. The aim was to analyse neonates with a diagnosis of seizures admitted to a tertiary hospital between November 2009 and May 2021, and their subsequent progression to epilepsy. Material and methods. A retrospective observational study was carried out using the hospital database. Information was collected on neonates with a discharge diagnosis of ‘seizures’ or ‘moderate or severe hypoxic-ischaemic encephalopathy’. Different variables were analysed: aetiology of the seizures, type, persistence over time, treatment and electroclinical correlates. RESULTS Of 165 patients, 55 presented neonatal seizures. As regards aetiology, 43 patients (78%) had seizures secondary to an acute event, of which 19 (34%) were hypoxic-ischaemic encephalopathies, and 22 (40%) had other acute disorders. Genetic alteration was found in six of them (11%). Thirteen patients (24%) progressed to subsequent epilepsy, of whom seven had symptomatic epilepsy, with a period of latency after the acute event in two patients. Six patients had neonatal epilepsy with unprovoked seizures. Twenty-two (62%) showed electroclinical correlates. All of the confirmed crises (100%) were focal. All the seizures were treated. The drug of choice was phenobarbital. CONCLUSIONS Diagnosis of neonatal seizures requires high clinical suspicion and electroclinical confirmation. Most of them progress favourably, but a percentage constitute the onset of epilepsy, the identification of which will determine their therapeutic management. (AU)

Peri-ictal EEG in infants with PRRT2-related self-limited infantile epilepsy.

OBJECTIVE: Pathogenic PRRT2 variants cause self-limited (familial) infantile epilepsy (SeLIE), which is responsive to sodium channel blocking antiseizure medications. The interictal EEG is typically normal. We describe a cohort of infants with PRRT2-related SeLIE with striking peri-ictal EEG abnormalities. METHODS: We included all infants diagnosed with PRRT2-related SeLIE during July 2020 to November 2021 at the Royal Children's Hospital, Melbourne. Clinical features and results of aetiologic investigations were collected from electronic medical records. All EEGs were reviewed independently by two epileptologists. RESULTS: Ten infants presented with focal seizures at a median age of 5 months (range: 3-6 months). Eight had a family history of epilepsy, paroxysmal kinesigenic dyskinesia (PKD) or hemiplegic migraine. Seven of the eight infants with an EEG performed within 24 h of the most recent seizure had epileptiform discharges. Their EEGs showed focal sharp waves, spikes, polyspikes or fast activity independently over the left and right temporo-occipital regions. Conversely, the two infants with last known seizure greater than 24 h prior to their EEG had no epileptiform discharges. Oxcarbazepine was commenced in two infants and was effective. Eight infants were initially treated with levetiracetam, and all were subsequently switched to oxcarbazepine due to ongoing seizures or side effects. SIGNIFICANCE: Posterior polymorphic focal epileptiform discharges on a peri-ictal EEG recording are a feature of PRRT2-related SeLIE. This finding, particularly in the presence of a family history of infantile epilepsy, PKD or hemiplegic migraine, suggests a diagnosis of PRRT2-related SeLIE and has important treatment implications.

PRRT2-positive self-limited infantile epilepsy: Initial seizure characteristics and response to sodium channel blockers.

OBJECTIVE: Self-limited infantile epilepsy (SeLIE) has distinctive clinical features, and the PRRT2 gene is known to be a considerable genetic cause. There have been a few studies on PRRT2-positive SeLIE only, and anti-seizure medications are often required due to frequent seizures at initial seizure onset. This study aimed to provide clinical information for the early recognition of patients with PRRT2-positive SeLIE and to propose effective anti-seizure medications for seizure control. METHODS: We retrospectively reviewed 36 patients diagnosed with SeLIE with genetically confirmed pathogenic variants of PRRT2. In addition, six atypical cases with neonatal-onset seizures and unremitting after 3 years of age were included to understand the expanded clinical spectrum of PRRT2-related epilepsy. We analyzed the initial presentation, clinical course, and seizure control response to anti-seizure medications. RESULTS: Patients with PRRT2-related epilepsy had characteristic seizure semiology at the initial presentation, including all afebrile, clustered (n = 23, 63.9%), short-duration (n = 33, 91.7%), and bilateral tonic-clonic seizures (n = 26, 72.2%). Genetic analysis revealed that c. 649dupC was the most common variant, and six patients had a 16p11.2 microdeletion containing the PRRT2 gene. One-third of the patients were sporadic cases without a family history of epilepsy or paroxysmal movement disorders. In the 33 patients treated with anti-seizure medications, sodium channel blockers, such as carbamazepine, were the most effective in seizure control. SIGNIFICANCE: Our results delineated the clinical characteristics of PRRT2-positive SeLIE, differentiating it from other genetic infantile epilepsies and discovered the effective anti-seizure medications for initial clustered seizure control. If afebrile bilateral tonic-clonic seizures develop in a normally developed infant as a clustered pattern, PRRT2-positive SeLIE should be considered as a possible diagnosis, and sodium channel blockers should be administered as the first medication for seizure control.

TMEM151A phenotypic spectrum includes paroxysmal kinesigenic dyskinesia with infantile convulsions.

In a three-generation family, five individuals exhibited the typical phenotype of paroxysmal kinesigenic dyskinesia (PKD). Intriguingly, one of the individuals also showed benign familial infantile convulsions (BFIC) at age 4 months and spontaneously resolved at age 18 months. At age 12, she developed a typical PKD, and was gradually relieved at age 21. Therefore, the clinical phenotype was consistent with PKD with infantile convulsions (PKD/IC). Whole exome sequence and co-segregation analysis revealed a novel heterozygous variant c.1085A > G in the TMEM151A gene. Our study suggests that the TMEM151A gene may be associated with the disease spectrum of PKD-PKD/IC-BFIC.

Early initial video-electro-encephalography combined with variant location predict prognosis of KCNQ2-related disorder.

BACKGROUND: The clinical features of KCNQ2-related disorders range from benign familial neonatal seizures 1 to early infantile epileptic encephalopathy 7. The genotype-phenotypic association is difficult to establish. OBJECTIVE: To explore potential factors in neonatal period that can predict the prognosis of neonates with KCNQ2-related disorder. METHODS: Infants with KCNQ2-related disorder were retrospectively enrolled in our study in Children's Hospital of Fudan University in China from Jan 2015 to Mar 2020. All infants were older than age of 12 months at time of follow-up, and assessed by Bayley Scales of Infant and Toddler Development-Third Edition (BSID-III) or Wechsler preschool and primary scale of intelligence-fourth edition (WPPSI-IV), then divided into three groups based on scores of BSID-III or WPPSI-IV: normal group, mild impairment group, encephalopathy group. We collected demographic variables, clinical characteristics, neuroimaging data. Considered variables include gender, gestational age, birth weight, age of the initial seizures, early interictal VEEG, variant location, delivery type. Variables predicting prognosis were identified using multivariate ordinal logistic regression analysis. RESULTS: A total of 52 infants were selected in this study. Early interictal video-electro-encephalography (VEEG) (ß = 2.77, 1.20 to 4.34, P = 0.001), and variant location (ß = 2.77, 0.03 to 5.5, P = 0.048) were independent risk factors for prognosis. The worse the early interictal VEEG, the worse the prognosis. Patients with variants located in the pore-lining domain or S4 segment are more likely to have a poor prognosis. CONCLUSIONS: The integration of early initial VEEG and variant location can predict prognosis. An individual whose KCNQ2 variant located in voltage sensor, the pore domain, with worse early initial VEEG background, often had an adverse outcome.

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.

Levetiracetam Versus Phenobarbital for Neonatal Seizures: A Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: There are no US Food and Drug Administration-approved therapies for neonatal seizures. Phenobarbital and phenytoin frequently fail to control seizures. There are concerns about the safety of seizure medications in the developing brain. Levetiracetam has proven efficacy and an excellent safety profile in older patients; therefore, there is great interest in its use in neonates. However, randomized studies have not been performed. Our objectives were to study the efficacy and safety of levetiracetam compared with phenobarbital as a first-line treatment of neonatal seizures. METHODS: The study was a multicenter, randomized, blinded, controlled, phase IIb trial investigating the efficacy and safety of levetiracetam compared with phenobarbital as a first-line treatment for neonatal seizures of any cause. The primary outcome measure was complete seizure freedom for 24 hours, assessed by independent review of the EEGs by 2 neurophysiologists. RESULTS: Eighty percent of patients (24 of 30) randomly assigned to phenobarbital remained seizure free for 24 hours, compared with 28% of patients (15 of 53) randomly assigned to levetiracetam (P < .001; relative risk 0.35 [95% confidence interval: 0.22-0.56]; modified intention-to-treat population). A 7.5% improvement in efficacy was achieved with a dose escalation of levetiracetam from 40 to 60 mg/kg. More adverse effects were seen in subjects randomly assigned to phenobarbital (not statistically significant). CONCLUSIONS: In this phase IIb study, phenobarbital was more effective than levetiracetam for the treatment of neonatal seizures. Higher rates of adverse effects were seen with phenobarbital treatment. Higher-dose studies of levetiracetam are warranted, and definitive studies with long-term outcome measures are needed.

Risk factors for neonatal seizures: A case-control study in the province of Parma, Italy.

PURPOSE: The present study evaluated the risk factors for electroencephalographic (EEG)-confirmed seizures during the whole neonatal period in preterm and term neonates born in the province of Parma between January 2009 and December 2014. METHODS: We selected as cases the infants that presented EEG-confirmed neonatal seizures (NS). Two population controls for each case were matched by gestational age (GA), sex, hospital, and period of birth. Information on the mother, the pregnancy, the labor and delivery, and the neonates were taken from the Emilia-Romagna Certificate of Delivery Assistance database and from hospital charts and ICD-9-CM codes. RESULTS AND INTERPRETATION: In the 6-year period of this study, 22 patients were recorded with NS. The association between at least one pregnancy complication and at least one neonatal complication, a low Apgar score, the need for resuscitation at birth, intraventricular hemorrhages (IVH) grades II-IV for preterm, and acute perinatal asphyxia/hypoxic-ischemic encephalopathy (HIE) for term infants were all statistically significant among cases. Neonates presenting these risk factors are more prone to develop NS and have to be strictly monitored.

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.

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.

Inter-rater reliability of amplitude-integrated EEG for the detection of neonatal seizures.

BACKGROUND: Amplitude-integrated electroencephalogram (aEEG) is being used increasingly for seizure detection in neonates. However, data regarding inter-rater reliability among neonatologists for the use of aEEG for the detection of neonatal seizures is lacking. METHODS: Term and late-preterm infants at risk of seizures were monitored simultaneously with 24-h video-electroencephalography (vEEG) and aEEG. vEEG was interpreted by an experienced neurologist. Five neonatologists with experience in aEEG interpretation from four different neonatal units interpreted aEEG recordings independently. The Brennan and Prediger kappa coefficient and Intra-class Correlation Coefficients (ICC) were used to assess inter-rater reliability between the neonatologists. RESULTS: Thirty-five infants at risk of seizure with gestational age at birth 35-42 weeks were recruited for the study after informed parental consent. vEEG detected seizures in seven infants with a total of 169 individual seizure episodes. Neonatologists detected seizures in 10 to 15 infants on aEEG. The sensitivities for the detection of individual seizures by neonatologists ranged from 18% to 38%. The inter-rater reliability for detection of: individual seizure was "fair" (kappa = 0.37; 95% CI: 0.32-0.42), infant with seizure was "moderate" (kappa = 0.60; 95% CI: 0.44-0.75), duration of individual seizure (ICC: 0.22; 95% CI: 0.18-0.28) and total duration of seizures in an infant (ICC: 0.46; 95% CI: 0.30-0.63) was "poor". The neonatologists missed 77-90% of the duration of seizures. CONCLUSION: The inter-rater reliability of aEEG for the detection of neonatal seizures was suboptimal. Even when interpreted by experienced and trained clinicians, seizure detection with aEEG has limitations and can miss large number and duration of seizures.

A novel de novo KCNQ2 mutation in a child with treatmentresistant early-onset epileptic encephalopathy.

Benetou C, Papailiou S, Maritsi D, Anagnostopoulou K, Kontos H, Vartzelis G. A novel de novo KCNQ2 mutation in a child with treatmentresistant early-onset epileptic encephalopathy. Turk J Pediatr 2019; 61: 279-281. Mutations in KCNQ2 gene, encoding for voltage-gated K+ channel subunit, may result in a wide spectrum of early-onset epileptic disorders. The phenotype of the disease varies from `benign familial neonatal seizures` to `severe epileptic encephalopathies`. In this report, we present a novel mutation [namely: c.683A > G (p.His228Arg)], as a presumable cause of severe infantile-onset neonatal seizures, in a 3-month old boy. The seizures have been poorly responsive to various pharmacological treatments, with phenytoin and carbamazepine presenting with the most favourable results so far. The study of our patient could help to further clarify the clinical manifestations of KCNQ2 mutations, revealing a previously unreported mutation.

Pitfalls of clinical exome and gene panel testing: alternative transcripts.

PURPOSE: Clinical exome and gene panel testing can provide molecular diagnoses for patients with rare Mendelian disorders, but for many patients these tests are nonexplanatory. We investigated whether interrogation of alternative transcripts in known disease genes could provide answers for additional patients. METHODS: We integrated alternative transcripts for known neonatal epilepsy genes with RNA-Seq data to identify brain-expressed coding regions that are not evaluated by popular neonatal epilepsy clinical gene panel and exome tests. RESULTS: We found brain-expressed alternative coding regions in 89 (30%) of 292 neonatal epilepsy genes. The 147 regions encompass 15,713 bases that are noncoding in the primary transcripts analyzed by the clinical tests. Alternative coding regions from at least 5 genes carry reported pathogenic variants. Three candidate variants in these regions were identified in public exome data from 337 epilepsy patients. Incorporating alternative transcripts into the analysis of neonatal epilepsy genes in 44 patient genomes identified the pathogenic variant for the epilepsy case and 2 variants of uncertain significance (VUS) among the 43 control cases. CONCLUSION: Assessment of alternative transcripts in exon-based clinical genetic tests, including gene panel, exome, and genome sequencing, may provide diagnoses for patients for whom standard testing is unrevealing, without introducing many VUS.

[Frequency, semiology and prognosis of benign infantile epilepsy]. / Frecuencia, semiologia y pronostico de la epilepsia infantil benigna.

INTRODUCTION: Benign infantile epilepsy is an epileptic syndrome of infancy. Until now, only a small number of case-series have been published. AIM: To study the frequency, semiology and prognosis of benign infantile epilepsy. PATIENTS AND METHODS: The 827 patients with one or more epileptic seizures seen at our hospital between 1 June 1994 and 1 March 2011 were included and prospectively followed. A diagnosis of benign infantile epilepsy was made in patients that fulfilled the following criteria at six month of evolution: one or more focal and/or generalised seizures, onset before 24 months, no neurological deficit and normal neuroimaging and interictal EEG. RESULTS: 77 cases (9%) met the diagnostic criteria. Semiology of the seizures was similar to that of other focal seizures in children under 24 months. 25% of the patients remained as isolated seizures. Among those with two or more seizures, the probability of achieving a 3 year initial remission without antiepileptic treatment was 86%. In the subgroup of patients with focal seizures without family history the probability was 74% and in five cases a global developmental delay/intellectual disability was detected thereafter. CONCLUSIONS: Benign infantile epilepsy is a frequent epileptic syndrome. Semiology of seizures is not useful to characterize the syndrome. A diagnosis of benign infantile epilepsy at six month of evolution implies a reasonably good prognosis, but possibly not as good as for other self-limited epilepsies of infancy.

TITLE: Frecuencia, semiologia y pronostico de la epilepsia infantil benigna.Introduccion. La epilepsia infantil benigna es un sindrome epileptico sobre el que hasta ahora se ha publicado tan solo un pequeño numero de series de casos. Objetivo. Estudiar la frecuencia, semiologia y pronostico de la epilepsia infantil benigna. Pacientes y metodos. Los 827 pacientes con una o mas crisis epilepticas no provocadas que consultaron en nuestro hospital entre el 1 de junio de 1994 y el 1 de marzo de 2011 fueron incluidos y seguidos prospectivamente. Se diagnosticaron de epilepsia infantil benigna los pacientes que cumplieron los siguientes criterios a los seis meses de evolucion: una o mas crisis focales o generalizadas, inicio antes de los 24 meses, ausencia de deficits neurologicos y electroencefalograma y neuroimagen normales. Resultados. Cumplieron los criterios diagnosticos 77 casos (9%). La semiologia de las crisis fue similar a la de otras crisis focales en niños menores de 24 meses. Un 25% de los pacientes permanecio como con crisis aisladas. Entre los de dos o mas crisis epilepticas, la probabilidad de alcanzar una remision inicial de tres años sin tratamiento antiepileptico fue del 86%. En el subgrupo de pacientes con crisis focales sin antecedentes familiares, la probabilidad fue del 74%, y en cinco casos se detecto posteriormente un retraso psicomotor o discapacidad intelectual. Conclusiones. La epilepsia infantil benigna es un sindrome epileptico frecuente. La semiologia de las crisis no es util para caracterizar el sindrome. El diagnostico de epilepsia infantil benigna a los seis meses de evolucion implica un pronostico razonablemente bueno, pero posiblemente no tanto como el de otras epilepsias autolimitadas de la infancia.

Weighted Performance Metrics for Automatic Neonatal Seizure Detection Using Multiscored EEG Data.

In neonatal intensive care units, there is a need for around the clock monitoring of electroencephalogram (EEG), especially for recognizing seizures. An automated seizure detector with an acceptable performance can partly fill this need. In order to develop a detector, an extensive dataset labeled by experts is needed. However, accurately defining neonatal seizures on EEG is a challenge, especially when seizure discharges do not meet exact definitions of repetitiveness or evolution in amplitude and frequency. When several readers score seizures independently, disagreement can be high. Commonly used metrics such as good detection rate (GDR) and false alarm rate (FAR) derived from data scored by multiple raters have their limitations. Therefore, new metrics are needed to measure the performance with respect to the different labels. In this paper, instead of defining the labels by consensus or majority voting, popular metrics including GDR, FAR, positive predictive value, sensitivity, specificity, and selectivity are modified such that they can take different scores into account. To this end, 353 hours of EEG data containing seizures from 81 neonates were visually scored by a clinical neurophysiologist, and then processed by an automated seizure detector. The scored seizures were mixed with false detections of an automated seizure detector and were relabeled by three independent EEG readers. Then, all labels were used in the proposed performance metrics and the result was compared with the majority voting technique and showed higher accuracy and robustness for the proposed metrics. Results were confirmed using a bootstrapping test.

[Benign infantile convulsions associated with mild gastroenteritis: a clinical analysis and follow-up study].

OBJECTIVE: To study the clinical features and prognosis of benign infantile convulsions associated with mild gastroenteritis (BICE). METHODS: A retrospective analysis was performed for the clinical data of 436 children with BICE, and among these children, 206 were followed up for 1.5 to 7 years. Some parents were invited to complete the Weiss Functional Defect Scale to evaluate the long-term social function. RESULTS: The peak age of onset of BICE was 13-24 months, and BICE had a higher prevalence rate in September to February of the following year. Convulsions mainly manifested as generalized tonic-clonic seizures, which often occurred within 24 hours after disease onset and lasted for less than 5 minutes each time. Sometimes they occurred in clusters. During the follow-up of 206 children, only one had epileptiform discharge, and the other children had normal electroencephalographic results. The parents of all the 206 children thought their children had normal intelligence and had no marked changes in character. Based on the Weiss Functional Defect Scale completed by the parents of some BICE children, there was no significant difference in the long-term social function between BICE children and healthy children matched by age and sex. CONCLUSIONS: BICE mainly occurs in children aged 1-2 years, with the manifestation of transient generalized seizures in most children and cluster seizures in some children. BICE seldom progresses to epilepsy and has good prognosis.

Corticokinematic coherence as a new marker for somatosensory afference in newborns.

OBJECTIVE: Somatosensory evoked potentials have high prognostic value in neonatal intensive care, but their recording from infants is challenging. Here, we studied the possibility to elicit cortical responses in newborns by simple passive hand movements. METHODS: We examined 13 newborns (postnatal age 1-46days) during clinically indicated 19-channel electroencephalography (EEG) recordings in the neonatal intensive care unit; EEG indications included birth asphyxia and suspected epileptic seizures. The experimenter moved the infant's wrist or fingers at 1 or 2Hz for 5-10min, separately on both sides. We measured movement kinematics with an accelerometer attached to the infant's hand and computed coherence between the EEG and acceleration signals (corticokinematic coherence, CKC). RESULTS: Statistically significant CKC (amplitude 0.020-0.511) with characteristic scalp topography was observed in all infants at twice the movement frequency. CKC was contralaterally dominant on the central scalp (median laterality index 0.48 for right-hand and -0.63 for left-hand movements). CONCLUSIONS: Passive movements elicit cortical responses that can be readily observed in clinical EEG recordings from newborns in the intensive-care environment. SIGNIFICANCE: CKC is a novel, noninvasive marker for the somatosensory system. Its robustness and practical ease make it attractive for bedside assessment of neurologically compromised newborns.

Exploring temporal information in neonatal seizures using a dynamic time warping based SVM kernel.

Seizure events in newborns change in frequency, morphology, and propagation. This contextual information is explored at the classifier level in the proposed patient-independent neonatal seizure detection system. The system is based on the combination of a static and a sequential SVM classifier. A Gaussian dynamic time warping based kernel is used in the sequential classifier. The system is validated on a large dataset of EEG recordings from 17 neonates. The obtained results show an increase in the detection rate at very low false detections per hour, particularly achieving a 12% improvement in the detection of short seizure events over the static RBF kernel based system.

Phenobarbital reduces EEG amplitude and propagation of neonatal seizures but does not alter performance of automated seizure detection.

OBJECTIVE: Phenobarbital increases electroclinical uncoupling and our preliminary observations suggest it may also affect electrographic seizure morphology. This may alter the performance of a novel seizure detection algorithm (SDA) developed by our group. The objectives of this study were to compare the morphology of seizures before and after phenobarbital administration in neonates and to determine the effect of any changes on automated seizure detection rates. METHODS: The EEGs of 18 term neonates with seizures both pre- and post-phenobarbital (524 seizures) administration were studied. Ten features of seizures were manually quantified and summary measures for each neonate were statistically compared between pre- and post-phenobarbital seizures. SDA seizure detection rates were also compared. RESULTS: Post-phenobarbital seizures showed significantly lower amplitude (p<0.001) and involved fewer EEG channels at the peak of seizure (p<0.05). No other features or SDA detection rates showed a statistical difference. CONCLUSION: These findings show that phenobarbital reduces both the amplitude and propagation of seizures which may help to explain electroclinical uncoupling of seizures. The seizure detection rate of the algorithm was unaffected by these changes. SIGNIFICANCE: The results suggest that users should not need to adjust the SDA sensitivity threshold after phenobarbital administration.

Benign infantile seizures and paroxysmal dyskinesia caused by an SCN8A mutation.

OBJECTIVE: Benign familial infantile seizures (BFIS), paroxysmal kinesigenic dyskinesia (PKD), and their combination-known as infantile convulsions and paroxysmal choreoathetosis (ICCA)-are related autosomal dominant diseases. PRRT2 (proline-rich transmembrane protein 2 gene) has been identified as the major gene in all 3 conditions, found to be mutated in 80 to 90% of familial and 30 to 35% of sporadic cases. METHODS: We searched for the genetic defect in PRRT2-negative, unrelated families with BFIS or ICCA using whole exome or targeted gene panel sequencing, and performed a detailed cliniconeurophysiological workup. RESULTS: In 3 families with a total of 16 affected members, we identified the same, cosegregating heterozygous missense mutation (c.4447G>A; p.E1483K) in SCN8A, encoding a voltage-gated sodium channel. A founder effect was excluded by linkage analysis. All individuals except 1 had normal cognitive and motor milestones, neuroimaging, and interictal neurological status. Fifteen affected members presented with afebrile focal or generalized tonic-clonic seizures during the first to second year of life; 5 of them experienced single unprovoked seizures later on. One patient had seizures only at school age. All patients stayed otherwise seizure-free, most without medication. Interictal electroencephalogram (EEG) was normal in all cases but 2. Five of 16 patients developed additional brief paroxysmal episodes in puberty, either dystonic/dyskinetic or "shivering" attacks, triggered by stretching, motor initiation, or emotional stimuli. In 1 case, we recorded typical PKD spells by video-EEG-polygraphy, documenting a cortical involvement. INTERPRETATION: Our study establishes SCN8A as a novel gene in which a recurrent mutation causes BFIS/ICCA, expanding the clinical-genetic spectrum of combined epileptic and dyskinetic syndromes.