[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.

Benign infantile convulsions (IC) and subsequent paroxysmal kinesigenic dyskinesia (PKD) in a patient with 16p11.2 microdeletion syndrome.

Paroxysmal kinesigenic dyskinesia with infantile convulsions (PKD/IC) is caused by mutations in the gene PRRT2 located in 16p11.2. A deletion syndrome 16p11.2 is well established and is characterized by intellectual disability, speech delay, and autism. PKD/IC, however, is extremely rare in this syndrome. We describe a case of PKD/IC and 16p11.2 deletion syndrome and discuss modifiers of PRRT2 activity to explain the rare concurrence of both syndromes.

"Benign" myoclonic epilepsy of infancy as the initial presentation of glucose transporter-1 deficiency.

We report the case of a young boy carrying a de novo missense mutation (c.1199G>T; p.R400L) in the SLC2A1 gene who presented initially with benign myoclonic epilepsy of infancy. Eventually, he had a poor outcome with refractory generalised tonic-clonic, myoclonic and absence seizures, ataxia, significant mental impairment and slowing of head growth. He responded poorly to ketogenic diet. This case extends the phenotype of GLUT1-related syndromes and also sheds light on the genetic basis of myoclonic epilepsies of infancy suggesting that variable outcome may depend on genetic factors. [Published with video sequences].

Brain cooling reduces the risk of postneonatal epilepsy in newborns affected by moderate to severe hypoxic-ischemic encephalopathy.

BACKGROUND: Neonatal hypoxic-ischemic encephalopathy is still a significant cause of neonatal death and neurodevelopmental disabilities, such as cerebral palsy, mental delay, and epilepsy. After the introduction of therapeutic hypothermia, the prognosis of hypoxic-ischemic encephalopathy has improved, with reduction of death and disabilities. However, few studies evaluated whether hypothermia affects rate and severity of postneonatal epilepsy. We evaluated rates, characteristics and prognostic markers of postneonatal epilepsy in infants with moderate to severe hypoxic-ischemic encephalopathy treated or not with therapeutic hypothermia. METHODS: We analyzed clinical data, EEG recordings, cerebral Magnetic Resonance Imaging (MRI) and outcome in 23 cooled and 26 non-cooled asphyxiated neonates (≥36 weeks' gestation), admitted from 2004 to 2012. RESULTS: Among 49 neonates 11 (22%) had postneonatal epilepsy, of which 9 (18%) were non-cooled and 2 (4%) were cooled (P=0.05). Six of 11 infants (55%) had West syndrome, 4 (36%) had focal epilepsy and 1 (9%) had Lennox-Gastaut Syndrome. At multiple logistic regression analysis MRI pattern significantly correlated with postneonatal epilepsy (OR 0.19, 95% CI 0.04-0.88, P=0.03). Extensive lesions in basal ganglia and thalami plus cortical and white matter were associated with postneonatal epilepsy. CONCLUSIONS: Only perinatal asphyxia with extensive lesions in basal ganglia and thalami plus cortical and white matter lesion conveys a high risk for early and severe postneonatal epilepsy. Moreover, therapeutic hypothermia is associated with a decrease of the risk of developing postneonatal epilepsy.

Timing of neonatal seizures and intrapartum obstetrical factors.

One hundred ninety-three neonates with seizures were available on a neonatal seizure database, which included intrapartum and neonatal factors such as labor duration, fetal heart rate abnormalities, cord blood gas values, Apgar scores and clinical signs of encephalopathy. Regression analyses (analysis of variance) were performed on the entire cohort as well as specific subsets of neonates (eg, neonatal encephalopathy vs no encephalopathy) to assess the relationship between seizure timing and intrapartum/neonatal factors. Seizures were noted earlier for the encephalopathic group than for the nonencephalopathic group. No significant differences were noted for any intrapartum or neonatal factors. Timing of neonatal seizures, with or without an encephalopathy occurs within the first 2 days after birth and is independent of selected intrapartum and neonatal factors, underscoring recent task force recommendations concerning neonatal encephalopathy. Factors other than intrapartum events more likely contribute to the encephalopathic repertoire of the newborn, including seizures.

[Convulsions in neonatal period and infancy with rare etiology (neurogenetic disease)]. / Ujszülött- ves csecsemokori görcsrohamok hatterében alló ritka neurogenetikai betegségek.

Authors summarized the etiology of convulsions in neonatal period and infancy (hypoxia, intracranial hemorrhage, infections of central nervous system, metabolic background, chromosomal abnormalities, brain developmental abnormalities, benign neonatal convulsions, benign neonatal familial convulsions, drug withdrawal, inborn error of metabolism). They suggest screening examinations after convulsion, summarized the basic principle of tandem examination and review a proposal at suspicion of inborn error of enzyme defects (aminoacidemias, defects of fatty acid oxidation, organic acidemias). They present case history of two patients suffered in extraordinary inborn error of enzyme defect (SCO2 gene mutation, propionic acidemia). Diagnosis originated in Helm P61 Hospital (settlement Madarász Hospital) with a Hungarian and international cooperation.

Benign familial neonatal convulsions caused by altered gating of KCNQ2/KCNQ3 potassium channels.

The muscarinic-regulated potassium current (M-current), formed by the heteromeric assembly of subunits encoded by the KCNQ2 and KCNQ3 genes, is a primary regulator of neuronal excitability; this regulation is accomplished by impeding repetitive firing and causing spike-frequency adaptation. Mutations in KCNQ2 or KCNQ3 cause benign familial neonatal convulsions (BFNC), a rare autosomal-dominant generalized epilepsy of newborns, by reducing the maximal current carried by the M-channels without affecting ion selectivity or gating properties. Here we show that KCNQ2/KCNQ3 channels carrying a novel BFNC-causing mutation leading to an arginine to tryptophan substitution in the voltage-sensing S4 domain of KCNQ2 subunits (R214W) displayed slower opening and faster closing kinetics and a decreased voltage sensitivity with no concomitant changes in maximal current or plasma membrane expression. These results suggest that mutation-induced gating alterations of the M-current may cause epilepsy in neonates.

Prognostic value of non-reactive burst suppression EEG pattern associated to early neonatal seizures.

UNLABELLED: Seizures are the most frequent neurological event in newborns and clinical data suggest that etiology is the dominant factor in long term outcome. However, there are consistent background EEG abnormalities associated to neonatal seizures that are usually related to unfavorable outcome as the burst-suppression pattern. OBJECTIVE: The objective of this study was to correlate clinical and EEG features associated to long-term outcome of newborns with non-reactive burst-suppression (BS) EEG. METHOD: Newborns included in the study were selected from our database and had conceptional age (at the time of first EEG) >37 weeks, EEG recordings with non-reactive BS available for review and clinical follow up. RESULTS: 12 newborns met inclusion criteria, 50% had seizures in the first day of life. Seizures became refractory to treatment in all of them. In 50% the etiology of seizures was considered cryptogenic, 33% had inborn errors of metabolism and 17% had clinical history and neuroimage suggestive of hypoxic-ischemic encephalopathy. The follow-up showed that 7/12 infants deceased, 3 during the first year of life, and one in the neonatal period. All the survivors had severe developmental delay and multifocal neurological impairment. 92% developed refractory epilepsy, 58% were latter diagnosed with West syndrome. CONCLUSION: The non-reactive BS pattern may appear related to many neonatal neurological disorders and is associated with early and refractory neonatal seizures. It is clearly associated with elevated morbidity and mortality and to the development of post-neonatal epilepsy.

Dysfunction of M-channel enhances propagation of neuronal excitability in rat hippocampus monitored by multielectrode dish and microdialysis systems.

To explore the pathogenesis of benign familial neonatal convulsions (BFNC), we determined effects of KCNQ-related M-channels (KCNQ-channels) on hippocampal glutamate (Glu) and gamma-aminobutyric acid (GABA) releases using microdialysis, and propagation of evoked field-potentials (FP) using multielectrode (64-ch)-dish system as two-dimensional monitoring. KCNQ-channel inhibitor, Dup996, enhanced hippocampal K(+)-evoked Glu and GABA releases without affecting basal releases of them. Dup996 unaffected FP-amplitude, but enhanced FP-propagation. The GABA(A)-receptor antagonist, bicuculline, enhanced the stimulatory effects of Dup996 on FP-propagation, however, this stimulatory effects of Dup996 were abolished by the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)/glutamate-receptor antagonist, DNQX. These results suggest that the occurrence of BFNC cannot be produced by KCNQ-channel dysfunction alone, but by reciprocal action between impaired KCNQ-channel and other unknown elements (possibly dysfunction of inhibitory neurotransmission system).

Prenatal and perinatal determinants of neonatal seizures occurring in the first week of life.

To evaluate prenatal and perinatal risk factors for early neonatal seizures, we conducted a case-control study including 100 newborns with neonatal seizures in the first week of life and 204 controls randomly selected from a list of healthy newborns born in the same hospital during the study period. Generalized tonic seizures were the most common seizures observed (29%), although the majority of newborns (71%) experienced more than one type of seizure. The most frequent presumed etiology of neonatal seizures was hypoxic-ischemic encephalopathy (30%). A history of epilepsy in first-degree relatives was found only for cases. Neonatal seizures were found to be associated with maternal disease in the 2 years before pregnancy, mother's weight gain > 14 kg during pregnancy, placental pathology, preeclampsia, low birthweight, low gestational age, and jaundice in the first 3 days of life. The need for cardiopulmonary resuscitation was found only for cases (37%). The causal pathways for neonatal seizures often begin before birth, and some of the factors identified may be preventable.

Persistent hyperinsulinemic hypoglycaemia followed as benign infantile convulsion.

An 18-month-old boy developed seizures at 3 months of age. He developed normally and, his EEG and brain CT revealed no abnormal findings. The blood sugar level was normal at that time, thus he was diagnosed as having benign infantile convulsion. At 7 months of age seizures reappeared, and hypoglycaemia associated with hyperinsulinism was observed during the seizures. With conservative therapy his blood sugar level was well controlled and he had no further seizures. Hypoglycaemic seizures are sometimes misdiagnosed as epilepsy. We have to pay attention to hyperinsulinemic hypoglycaemia when we see seizures with normal EEG even in infants.

[Idiopathic epileptic syndromes of the newborn]. / Síndromes epilépticos idiopáticos del recién nacido.

INTRODUCTION: Seizures during the neonatal period are the characteristic clinical expression of dysfunction of the nervous system. Not all the seizures seen during the neonatal period are due to epilepsy which only occurs in 10%. DEVELOPMENT: The aetiology of neonatal seizures is very varied and is mainly due to different types of aggression to the brain during this early stage of life. Epileptic syndromes are very rare during the neonatal period. In general the prognosis is very bad as occurs in infantile epileptic encephalopathy of early onset or myoclonic encephalopathy of early onset. However, the International League Against Epilepsy (ILAE) has identified and recognized some idiopathic epileptic syndromes of the neonatal period with a somewhat better prognosis. Two major groups have been established including the benign neonatal epilepsies (benign idiopathic neonatal epilepsies and benign familial neonatal seizures) and the group of status epilepticus (severe idiopathic status epilepticus). CONCLUSION: We analyze the different types of epilepsy of the newborn, form of onset, current knowledge of molecular biology, treatment and prognosis.

[A case with mild subdural hematoma presenting with a transient cluster of convulsions--problems concerning differentiation from benign infantile convulsion and benign complex partial epilepsies in infancy].

A 1-month-old girl showed frequent partial seizures of sudden onset. Continuous spikes were observed in left central area during the ictal period, although interictal EEG showed neither epileptiform discharges nor focal signs. Optimal seizures control was obtained with intravenous administration of diazepam and subsequent oral administration of phenobarbital. She showed neither abnormal physical and neurological signs after seizures nor sequelae. CT examination on two days after the onset of seizures showed no obvious abnormal high density area. However, MRI examination on 10 days after the onset showed subdural hematoma in the left front-temporal area and right occipital area. Except for MRI findings, this case may be diagnosed as benign infantile convulsion or benign complex partial epilepsies in infancy. This case suggested that serial neuroradiological examinations were recommended for prospective studies about benign infantile convulsion and benign complex partial epilepsies in infancy.

Intrapartum temperature elevation, epidural use, and adverse outcome in term infants.

OBJECTIVES: To examine the association of intrapartum temperature elevation with adverse neonatal outcome among low-risk women receiving epidural analgesia and evaluate the association of epidural with adverse neonatal outcome without temperature elevation. METHODS: We studied all low-risk nulliparous women with singleton pregnancies ≥37 weeks delivering at our hospital during 2000, excluding pregnancies where infants had documented sepsis, meningitis, or a major congenital anomaly. Neonatal outcomes were compared between women receiving (n = 1538) and not receiving epidural analgesia (n = 363) in the absence of intrapartum temperature elevation (≤99.5°F) and according to the level of intrapartum temperature elevation within the group receiving epidural (n = 2784). Logistic regression was used to evaluate neonatal outcome while controlling for confounders. RESULTS: Maternal temperature >100.4°F developed during labor in 19.2% (535/2784) of women receiving epidural compared with 2.4% (10/425) not receiving epidural. In the absence of intrapartum temperature elevation (≤99.5°F), no significant differences were observed in adverse neonatal outcomes between women receiving and not receiving epidural. Among women receiving epidural, a significant linear trend was observed between maximum maternal temperature and all neonatal outcomes examined including hypotonia, assisted ventilation, 1- and 5-min Apgar scores <7, and early-onset seizures. In regression analyses, infants born to women with fever >101°F had a two- to sixfold increased risk of all adverse outcomes examined. CONCLUSIONS: The proportion of infants experiencing adverse outcomes increased with the degree of epidural-related maternal temperature elevation. Epidural use without temperature elevation was not associated with any of the adverse outcomes we studied.

Lack of potassium current in W309R mutant KCNQ3 channel causing benign familial neonatal convulsions (BFNC).

BFNC is an autosomal dominant epileptic disorder caused by mutations of KCNQ2 or KCNQ3 potassium channel gene. W309R missense mutation in KCNQ3 gene was previously reported in a family with BFNC. In this study, potassium currents were recorded from HEK293 cells expressing both W309R mutant KCNQ3 and wild type KCNQ2 channels. We found a lack of potassium current in W309R mutant KCNQ3 and KCNQ2 channels, which can explain the hyper-excitability of CNS in patients with BFNC.

Neonatal seizures: gaps between the laboratory and the clinic.

UNLABELLED: Seizures in neonates (NBs) remain the most frequent neurological problem in the nursery. Considerable debate about their consequences exists between data and deductions reached through animal experimentations and those obtained through clinical investigations. The main conflicting issues are whether seizures in NBs can plant the roots for epileptogenesis and cause long-term deficits. The purpose of this chapter is to evaluate both laboratory and clinical results. METHODS: Clinical data will be presented, including a 20-year-long cohort of NBs. This will be followed by the main seminal discoveries obtained in neonatal models. The phenomenon of transient or persistent dysmaturity following NB seizures will be discussed in relation to etiological factors. RESULTS: The findings and deductions from animal models support the notions that epileptogenesis and cognitive deficits result from NB seizures. These conclusions contrast with clinical investigations maintaining that NB seizures, per se, are symptomatic markers of preexisting or of ongoing morbidities. The reasons for contrasting views will be discussed. Suggestions will be advanced for more animal models whose seizures are consistent with the etiologies and the phenotypes of human NB seizures.

[Convulsions in the early neonatal period]. / Konvulzije rane neonatalne dobi.

Convulsions are relatively frequent in neonatal population. They are also the most dramatic sign of a disorder of the central nervous system. Clinical signs of convulsive seizures in neonatal period differ greatly from those occurring in a later stage. Our study involves a five year period, in the course of which we analysed all newborns with convulsions occurring in the early neonatal period. The objective of the study was to determine the incidence, aetiology and time of occurrence of convulsions, to determine the mortality rate in this group of newborns and to assess risk factors for the development of convulsions. In 29.423 newborns tested in the course of the study at our Clinic, convulsions were found in 38 (0.13%) of them. Regarding the gestation age, 68.4% of the cases of convulsion occurred in at term newborns. The most frequent aetiology factor was a perinatal damage, in 60.4%, and the majority of convulsive seizures occurred in the period between the 2nd and 7th day (84.3%). Five of the tested newborns died (13.5%), three of them having suffered from convulsions in the first 24 hours. The authors came to the conclusion that many factors influence the development of convulsions, and that the occurrence of convulsions in the first 24 hours and heavy perinatal brain damage give bad prognostics for survival.

Impaired M-current and neuronal excitability.

PURPOSE: Benign familial neonatal convulsions (BFNC), a hereditary epilepsy, occurs specifically in newborns and remits spontaneously after this period. Several mutations of either KCNQ2 or KCNQ3, members of the KCNQ-related K+-channel (KCNQ-channel) family, were identified as a cause of BFNC. Such mutations impair KCNQ-related M- current, an element of the inhibitory system in the central nervous system (CNS), and therefore are thought to result in neuronal hyperexcitability. METHODS: To clarify the pathogenesis of BFNC, this study investigated the effects of the KCNQ channel on propagation of neuronal excitability using a 64-channel multielectrode dish (MED64) system for novel two-dimensional monitoring of evoked field potentials including fiber volley (FV) and field excitatory postsynaptic potential (fEPSP). RESULTS: Dup996, a selective KCNQ-channel inhibitor, did not affect the amplitude of FV or fEPSP, but enhanced the FV and fEPSP propagation. The gamma-aminobutyric acid (GABA)A-receptor antagonist, bicuculline, enhanced their propagation, whereas alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA)/glutamate-receptor antagonist, DNQX, reduced both amplitude and propagation of fEPSP without affecting those of FV. Under the condition of GABAA-receptor blockade by bicuculline, Dup996 enhanced the amplitude of fEPSP and propagation of FV and fEPSP without affecting the amplitude of FV. Dup996 enhanced the stimulating effects of bicuculline on the propagation and amplitude of FV and fEPSP, but it did not affect the inhibiting effects of DNQX. CONCLUSIONS: These results suggest that the occurrence of BFNC cannot be produced by KCNQ-channel dysfunction alone but by reciprocal action between impaired KCNQ channel and the other unknown.