Genetic etiologies of the electrical status epilepticus during slow wave sleep: systematic review

Clinical analysis of developmental and/or epileptic encephalopathy with spike-and-wave activation in sleep: A single tertiary care center experience in China

PURPOSE

To analyze the electroclinical features of patients with developmental and/or epileptic encephalopathy with spike-and-wave activation in sleep (DEE/EE-SWAS) and study the efficacy of different therapies on seizure control, electroencephalogram (EEG) improvements of electrical status epilepticus during sleep (ESES), and cognition outcomes.

METHODS

Patients with DEE/EE-SWAS who underwent at least one follow-up EEG 3 months after therapy were retrospectively enrolled. The demographic and clinical characteristics of the patients were analyzed. Variables that influenced the outcomes were evaluated using logistic regression models.

RESULTS

In total, 87 patients (47 males) were included. The median age at ESES recognition was 81.0 months (IQR 64.0, 96.0). Forty-six patients were diagnosed with self-limited focal epilepsies (SeLFEs) before ESES recognition, 24 with developmental and epileptic encephalopathies with spike-and-wave activation in sleep (DEE-SWAS), and 17 with other epilepsies. Steroids, benzodiazepines, and antiseizure medications (ASMs) were the initial treatment options for ESES. Patients with structural etiologies or slow EEG backgrounds at the time of ESES recognition were less likely to respond to treatment than other patients. However, only children with slow EEG backgrounds had lower odds of response in logistic regression models. Children with clinical or EEG response showed improvements in cognition.

CONCLUSION

Steroids, benzodiazepines, and ASMs are effective treatments for patients with DEE/EE-SWAS. Children with structural etiologies or slow EEG backgrounds at the time of ESES recognition may have a poor long-term prognosis. The efficacy of seizure reduction and EEG improvement is associated with cognitive improvement.

Expanding the clinical and genetic landscape of (developmental) epileptic encephalopathy with spike-and-wave activation in sleep: results from studies of a Turkish cohort

The terms developmental epileptic encephalopathy with spike-and-wave activation in sleep (DEE-SWAS) and epileptic encephalopathy with spike-and-wave activation in sleep (EE-SWAS) designate a spectrum of conditions that are typified by different combinations of motor, cognitive, language, and behavioral regression linked to robust spike-and-wave activity during sleep. In this study, we aimed at describing the clinical and molecular findings in "(developmental) epileptic encephalopathy with spike-and-wave activation in sleep" (D)EE-SWAS) patients as well as at contributing to the genetic etiologic spectrum of (D)EE-SWAS. Single nucleotide polymorphism (SNP) array and whole-exome sequencing (WES) techniques were used to determine the underlying genetic etiologies. Of the 24 patients included in the study, 8 (33%) were female and 16 (67%) were male. The median age at onset of the first seizure was 4 years and the median age at diagnosis of (D)EE-SWAS was 5 years. Of the 24 cases included in the study, 13 were compatible with the clinical diagnosis of DEE-SWAS and 11 were compatible with the clinical diagnosis of EE-SWAS. Abnormal perinatal history was present in four cases (17%), and two cases (8%) had a family history of epilepsy. Approximately two-thirds (63%) of all patients had abnormalities detected on brain computerized tomography/magnetic resonance (CT/MR) imaging. After SNP array and WES analysis, the genetic etiology was revealed in 7 out of 24 (29%) cases. Three of the variants detected were novel (SLC12A5, DLG4, SLC9A6). This study revealed for the first time that Smith-Magenis syndrome, SCN8A-related DEE type 13 and SLC12A5 gene variation are involved in the genetic etiology of (D)EE-SWAS. (D)EE-SWAS is a genetically diverse disorder with underlying copy number variations and single-gene abnormalities. In the current investigation, rare novel variations in genes known to be related to (D)EE-SWAS and not previously reported genes to be related to (D)EE-SWAS were discovered, adding to the molecular genetic spectrum. Molecular etiology enables the patient and family to receive thorough and accurate genetic counseling as well as a personalized medicine approach.

Biallelic pathogenic variants of PARS2 cause developmental and epileptic encephalopathy with spike-and-wave activation in sleep

BACKGROUND

Biallelic pathogenic variants in the mitochondrial prolyl-tRNA synthetase 2 gene (PARS2, OMIM * 612036) have been associated with Developmental and Epileptic Encephalopathy-75 (DEE-75, MIM #618437). This condition is typically characterized by early-onset refractory infantile spasms with hypsarrhythmia, intellectual disability, microcephaly, cerebral atrophy with hypomyelination, lactic acidemia, and cardiomyopathy. Most affected individuals do not survive beyond the age of 10 years.

METHODS

We describe a patient with early-onset DEE, consistently showing an EEG pattern of Spike-and-Wave Activation in Sleep (SWAS) since childhood. The patient underwent extensive clinical, metabolic and genetic investigations, including whole exome sequencing (WES).

RESULTS

WES analysis identified compound heterozygous variants in PARS2 that have been already reported as pathogenic. A literature review of PARS2-associated DEE, focusing mainly on the electroclinical phenotype, did not reveal the association of SWAS with pathogenic variants in PARS2. Notably, unlike previously reported cases with the same genotype, this patient had longer survival without cardiac involvement or lactic acidosis, suggesting potential genetic modifiers contributing to disease variability.

CONCLUSION

These findings widen the genetic heterogeneity of DEE-SWAS, including PARS2 as a causative gene in this syndromic entity, and highlight the importance of prolonged sleep EEG recording for the recognition of SWAS as a possible electroclinical evolution of PARS2-related DEE.

Continuous Spikes and Waves During Sleep (CSWS), Severe Epileptic Encephalopathy, and Choreoathetosis due to Mutations in FRRS1L

Background. Biallelic pathogenic variants in the FRRS1L gene are now known to cause developmental and epileptic encephalopathy-37 (DEE37). It can also be associated with chorea and continuous spikes and waves during sleep (CSWS). CSWS is a rare age-related epileptic encephalopathy syndrome of childhood that is characterized by seizures, neurocognitive regression and electrical status epilepticus during sleep (ESES) on electroencephalogram (EEG) that evolves in four stages. Seizures start during the prodromal phase but the ESES on EEG appears only during acute stage and this is the stage when the diagnosis of CSWS can be made. Methods. We present two patients with FRRS1L mutation causing DEE37 with CSWS. We also review twenty-nine cases of DEE37 described in the literature before and discuss its association with CSWS in the total cohort of thirty-one cases. Results. Developmental regression was found in 80% of the patients, mean age of seizure onset was 18 months, ESES or slow spike and wave on the EEG were reported mostly in the older patients (median age of 11 years) and hypsarrhythmia was reported in younger patients (median age of 4 years). This could suggest that if the younger patients were followed longer their EEG would have evolved into ESES during the acute stage of this syndrome and a diagnosis of CSWS could be made. Conclusion. Recognizing ESES and the natural evolution of CSWS is important in diagnosis and proper management of these patients. More detailed report of EEG findings and the evolution of epilepsy and development are needed to further characterize this syndrome.

Early recognition of characteristic conventional and amplitude-integrated EEG patterns of seizures in SCN2A and KCNQ3-related epilepsy in neonates

PURPOSE

Early recognition of seizures in neonates secondary to pathogenic variants in potassium or sodium channel coding genes is crucial, as these seizures are often resistant to commonly used anti-seizure medications but respond well to sodium channel blockers. Recently, a characteristic ictal amplitude-integrated electroencephalogram (aEEG) pattern was described in neonates with KCNQ2-related epilepsy. We report a similar aEEG pattern in seizures caused by SCN2A- and KCNQ3-pathogenic variants, as well as conventional EEG (cEEG) descriptions.

METHODS

International multicentre descriptive study, reporting clinical characteristics, aEEG and cEEG findings of 13 neonates with seizures due to pathogenic SCN2A- and KCNQ3-variants. As a comparison group, aEEGs and cEEGs of neonates with seizures due to hypoxic-ischemic encephalopathy (n = 117) and other confirmed genetic causes affecting channel function (n = 55) were reviewed.

RESULTS

In 12 out of 13 patients, the aEEG showed a characteristic sequence of brief onset with a decrease, followed by a quick rise, and then postictal amplitude attenuation. This pattern correlated with bilateral EEG onset attenuation, followed by rhythmic discharges ending in several seconds of post-ictal amplitude suppression. Apart from patients with KCNQ2-related epilepsy, none of the patients in the comparison groups had a similar aEEG or cEEG pattern.

DISCUSSION

Seizures in SCN2A- and KCNQ3-related epilepsy in neonates can usually be recognized by a characteristic ictal aEEG pattern, previously reported only in KCNQ2-related epilepsy, extending this unique feature to other channelopathies. Awareness of this pattern facilitates the prompt initiation of precision treatment with sodium channel blockers even before genetic results are available.

Serum Levels of Neuropeptides in Epileptic Encephalopathy With Spike-and-Wave Activation in Sleep

BACKGROUND

Epileptic encephalopathy with spike-and-wave activation in sleep (EE-SWAS) is a syndrome of childhood, characterized by diffuse or generalized spike-wave activity in electroencephalography during non-rapid eye movement sleep. Neuropeptides have been demonstrated in several studies to function in the sleep-wake cycle and display convulsant and anticonvulsant features. In this study, we aimed to investigate the relationship between EE-SWAS and neuropeptides such as dynorphin, galanin, ghrelin, leptin, melatonin, and orexin.

METHODS

This multicenter study was conducted from July 2019 to January 2021. There were three groups: Group 1 contained patients with EE-SWAS. Group 2 consisted of patients with self-limited focal epilepsy of childhood (SeLFE), and group 3 was the control group. Levels of neuropeptides were compared in the sera of these three groups.

RESULTS

There were 59 children aged between four and 15 years. Group 1 contained 14 children, group 2 contained 24 children, and group 3 contained 21 children. The level of leptin is higher and the level of melatonin is lower in group 1 than in group 3 (P = 0.01 and P = 0.005, respectively). In group 3, the level of orexin was lower than in both groups 2 and 3 (P = 0.01 and P = 0.01).

CONCLUSIONS

These data show that the level of leptin was higher and the level of melatonin was lower in patients with EE-SWAS than in the control group. Furthermore, patients with EE-SWAS had lower orexin levels than both the control group and patients with SeLFE. Further research is required to understand the potential role of these neuropeptides in the pathophysiology of EE-SWAS.

Developmental and/or epileptic encephalopathy with spike-and-wave activation in sleep in Saudi Arabia: Electroclinical, etiologic, genetic, and outcome multicenter study

OBJECTIVES

To investigate the clinical features of developmental and/or epileptic encephalopathy with spike-and-wave activation in sleep (D/EE-SWAS), its electrographic characteristics, and etiology and to compare the effects of different treatment strategies on the outcomes using a Saudi Arabian database.

METHODS

This multicenter study included children with D/EE-SWAS who were evaluated between 2010 and 2020 at 11 tertiary centers. Data were collected on their baseline clinical features, etiologies, and treatment modalities. Seizure reduction, spike-wave index, and cognitive state were examined as potential therapeutic outcomes.

RESULTS

Ninety-one children were diagnosed with D/EE-SWAS, with a median age of 7 years (IQR: 3-5) and an almost equal sex distribution. The average age at which epilepsy was diagnosed was 3 years (IQR: 5-2). A genetic/metabolic etiology was found in 35.1% of the patients, and a structural etiology was found in 27.4%. Children with underlying genetic/metabolic diseases exhibited an earlier seizure onset (P = 0.001) than children with other etiologies. Benzodiazepines (76.6%) were the most common treatment, followed by steroids (51.9%). Sodium valproate (75%) was the most frequently used antiseizure medication, followed by levetiracetam (64.9%). Children with a later seizure onset were more likely to have better clinical responses (P = 0.046), EEG responses (P = 0.012), and cognitive outcomes (P = 0.006) than children with an earlier onset. Moreover, better seizure response and electrographic response were seen in patients with bilateral interictal discharges on the EEG than otherwise. Children had a higher likelihood of both clinical and electrographic improvement with combination therapy of benzodiazepines (P = 0.001) and steroids (P = 0.001) than with other therapies.

SIGNIFICANCE

This study shows a higher prevalence of genetic/metabolic causes and suggests the superior efficacy of combination therapy with steroids and benzodiazepines in D/EE-SWAS. Prospective studies that strictly assess the treatment protocols and outcomes are needed.

GRIN2A-related epilepsy and speech disorders: A comprehensive overview with a focus on the role of precision therapeutics

Language dysfunction is a common and serious comorbidity of epilepsy, especially in individuals with epilepsy aphasia spectrum syndromes. Childhood epilepsy with centrotemporal spikes is on the mild end of the spectrum, while epileptic encephalopathy with continuous spike-and-wave during sleep syndrome is on the severe end. Traditional antiseizure medicines and immunotherapy are currently used to treat severely affected patients, but the results are usually disappointing. The discovery that GRIN2A is the primary monogenic etiology of these diseases has opened the door to precision treatments. The GRIN2A gene encodes GluN2A protein, which constitutes a subunit of the NMDA receptor (NMDAR). The GRIN2A pathogenic variants cause gain or loss of function of NMDAR; the former can be treated with uncompetitive NMDAR antagonists, such as memantine, while the latter with NMDAR co-agonist serine. Hyper-precision therapies with various other effective agents are likely to be developed shortly to target the diverse functional effects of different variants. Precision treatments for GRIN2A-related disorders will benefit those who suffer from the condition and pave the way for new therapeutic approaches to a variety of other NMDAR-linked neurodegenerative and psychiatric diseases (schizophrenia, Parkinson's disease, Alzheimer's disease, and so on). Furthermore, more research into GRIN2A-related disorders will help us better understand the neuroinflammatory and neuroimmunological basis of epilepsy, as well as the pathological and physiological network activation mechanisms that cause sleep activation of central-temporal spikes and language impairment.

Clinical Spectrum and Treatment Outcomes of Patients with Developmental and/or Epileptic Encephalopathy with Spike-and-Wave Activation in Sleep

Purpose: Developmental and/or epileptic encephalopathy with spike-and-wave activation in sleep (D/EE-SWAS) is a spectrum of conditions characterized by various phenotypes of cognitive, linguistic, and behavioral regression associated with spike-and-wave activation in sleep. We aimed to investigate the phenotypic spectrum and treatment outcomes of pediatric patients with D/EE-SWAS.Methods: We retrospectively analyzed the medical records of pediatric patients diagnosed with D/EE-SWAS and treated at Severance Children’s Hospital from 2006 to 2022. We extracted information from their medical records on electroencephalography before and after treatment, types of treatment, seizure frequency, and developmental profiles. The primary outcome was reduction of the spike-wave index on electroencephalography after treatment.Results: Twenty-one patients with a median age of 5.3 years (interquartile range, 4.1 to 6.6) at diagnosis were included. Ten patients had delayed development. The patients received various anti-seizure medications. Fourteen received long-term, high-dose steroid therapy, 10 were placed on a ketogenic diet, four received intravenous steroid pulse therapy, and one each was treated with intravenous immunoglobulin and cannabidiol. The most effective treatments were steroid therapy and a ketogenic diet, which were also effective in reducing seizures and improving cognition. Side effects during treatment were transient and treatable.Conclusion: We described the clinical spectrum of pediatric patients with D/EE-SWAS. Steroid therapy and a ketogenic diet can be considered effective therapeutic options for patients with D/EE SWAS.

The Interaction Between Sleep and Epilepsy

PURPOSE OF REVIEW

To review the mutual interactions between sleep and epilepsy, including mechanisms of epileptogenesis, the relationship between sleep apnea and epilepsy, and potential strategies to treat seizures.

RECENT FINDINGS

Recent studies have highlighted the role of functional network systems underlying epileptiform activation in sleep in several epilepsy syndromes, including absence epilepsy, benign focal childhood epilepsy, and epileptic encephalopathy with spike-wave activation in sleep. Sleep disorders are common in epilepsy, and early recognition and treatment can improve seizure frequency and potentially reduce SUDEP risk. Additionally, epilepsy is associated with cyclical patterns, which has led to new treatment approaches including chronotherapy, seizure monitoring devices, and seizure forecasting. Adenosine kinase and orexin receptor antagonists are also promising new potential drug targets that could be used to treat seizures. Sleep and epilepsy have a bidirectional relationship that intersects with many aspects of clinical management. In this article, we identify new areas of research involving future therapeutic opportunities in the field of epilepsy.

Altered Closed State Inactivation Gating in Kv4.2 Channels Results in Developmental and Epileptic Encephalopathies in Human Patients

Kv4.2 subunits, encoded by KCND2, serve as the pore-forming components of voltage-gated, inactivating I_SA K⁺ channels expressed in the brain. I_SA channels inactivate without opening in response to subthreshold excitatory input, temporarily increasing neuronal excitability, the back propagation of action potentials, and Ca²⁺ influx into dendrites, thereby regulating mechanisms of spike timing-dependent synaptic plasticity. As previously described, a de novo variant in Kv4.2, p.Val404Met, is associated with an infant-onset developmental and epileptic encephalopathy (DEE) in monozygotic twin boys. The p.Val404Met variant enhances inactivation directly from closed states, but dramatically impairs inactivation after channel opening. We now report the identification of a closely related, novel, de novo variant in Kv4.2, p.Val402Leu, in a boy with an early-onset pharmacoresistant epilepsy that evolved to an epileptic aphasia syndrome (Continuous Spike Wave during Sleep Syndrome). Like p.Val404Met, the p.Val402Leu variant increases the rate of inactivation from closed states, but significantly slows inactivation after the pore opens. Although quantitatively the p.Val402Leu mutation alters channel kinetics less dramatically than p.Val404Met, our results strongly support the conclusion that p.Val402Leu and p.Val404Met cause the clinical features seen in the affected individuals and underscore the importance of closed state inactivation in I_SA channels in normal brain development and function. This article is protected by copyright. All rights reserved.

PURA-Related Developmental and Epileptic Encephalopathy: Phenotypic and Genotypic Spectrum

BACKGROUND AND OBJECTIVES

Purine-rich element-binding protein A (PURA) gene encodes Pur-α, a conserved protein essential for normal postnatal brain development. Recently, a PURA syndrome characterized by intellectual disability, hypotonia, epilepsy, and dysmorphic features was suggested. The aim of this study was to define and expand the phenotypic spectrum of PURA syndrome by collecting data, including EEG, from a large cohort of affected patients.

METHODS

Data on unpublished and published cases were collected through the PURA Syndrome Foundation and the literature. Data on clinical, genetic, neuroimaging, and neurophysiologic features were obtained.

RESULTS

A cohort of 142 patients was included. Characteristics of the PURA syndrome included neonatal hypotonia, feeding difficulties, and respiratory distress. Sixty percent of the patients developed epilepsy with myoclonic, generalized tonic-clonic, focal seizures, and/or epileptic spasms. EEG showed generalized, multifocal, or focal epileptic abnormalities. Lennox-Gastaut was the most common epilepsy syndrome. Drug refractoriness was common: 33.3% achieved seizure freedom. We found 97 pathogenic variants in PURA without any clear genotype-phenotype associations.

DISCUSSION

The PURA syndrome presents with a developmental and epileptic encephalopathy with characteristics recognizable from neonatal age, which should prompt genetic screening. Sixty percent have drug-resistant epilepsy with focal or generalized seizures. We collected more than 90 pathogenic variants without observing overt genotype-phenotype associations.

Electrical Status Epilepticus during Sleep and Evaluating the Electroencephalogram

Electrical status epilepticus during sleep (ESES) is an age-related, self-limited epileptic encephalopathy characterized by heterogeneous clinical manifestations and a specific electroencephalographic pattern of continuous spikes and waves during slow sleep. The etiology of ESES is not completely clear, although structural brain lesions, abnormal immunological markers, and genetic mutations have been associated with the syndrome. ESES was first described in 1971 and since then, the diagnostic criteria have changed multiple times. Additionally, inconsistency between authors in how to record and evaluate the electroencephalogram also leads to variability between studies. These inconsistencies hamper objectivity, comparison, and generalization. Because of this, one of the first priorities of physicians treating this condition should be defining the parameters of this disease so that cooperative building can occur.

IL1RAPL1 Gene Deletion in a Female Patient with Developmental Delay and Continuous Spike-Wave during Sleep

Interleukin-1 receptor accessory protein-like 1 (IL1RAPL1) encodes a protein that is highly expressed in neurons and has been shown to regulate neurite outgrowth as well as synapse formation and synaptic transmission. Clinically, mutations in or deletions of IL1RAPL1 have been associated with a spectrum of neurological dysfunction including autism spectrum disorder and nonsyndromic X-linked developmental delay/intellectual disability of varying severity. Nearly all reported cases are in males; in the few reported cases involving females, the clinical presentation was mild or the deletion was identified in phenotypically normal carriers in accordance with X-linked inheritance. Using genome-wide microarray analysis, we identified a novel de novo 373 kb interstitial deletion of the X chromosome (Xp21.1-p21.2) that includes exons 4 to 6 of the IL1RAPL1 gene in an 8-year-old girl with severe intellectual disability and behavioral disorder with a history of developmental regression. Overnight continuous video electroencephalography revealed electrical status epilepticus in sleep (ESES). This case expands the clinical genetic spectrum of IL1RAPL1-related neurodevelopmental disorders and highlights a new genetic association of ESES.

Corpus callosotomy in pediatric patients with non-lesional epileptic encephalopathy with electrical status epilepticus during sleep

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Corpus callosotomy (CC) was performed in 3 pediatric patients with refractory epileptic encephalopathy with ESES.

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IQ was improved after CC with complete resolution of ESES in one patient.

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Developmental regression ceased after CC with worthwhile seizure reduction and temporary improvement of ESES in 2 patients.

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Epileptiform discharges disappeared or became lateralized after CC.

Epileptic encephalopathy with electrical status epilepticus during sleep (ESES) is often refractory to medical treatment and leads to poor cognitive outcomes. Corpus callosotomy may be an effective treatment option for drug-resistant ESES with no focal etiology. We retrospectively identified three patients who underwent corpus callosotomy for drug-resistant ESES in our institution. Electroencephalography (EEG) findings and cognitive functions were evaluated before surgery, at 3 months, 6 months, 1 year, and 2 years after surgery. Age at surgery was 6 years 10 months, 7 years 9 months, and 8 years 4 months, respectively. Period between the diagnosis of ESES and surgery ranged from 7 to 25 months. All patients had no obvious structural abnormalities and presented with cognitive decline despite multiple antiseizure medications and steroid therapies. One patient showed complete resolution of ESES and an improvement of intelligence quotient after surgery. Epileptiform EEG was lateralized to one hemisphere after surgery and spike wave index (SWI) was decreased with moderate improvement in development and seizures in the other 2 patients. SWI re-exacerbated from 6 months after surgery, but without subsequent developmental regression in these 2 patients. Corpus callosotomy may become an important treatment option for drug-resistant ESES in patients with no structural abnormalities.

Differential Functional Changes of Nav1.2 Channel Causing SCN2A-Related Epilepsy and Status Epilepticus During Slow Sleep

Background: Nav1.2 encoded by the SCN2A gene is a brain-expressed voltage-gated sodium channel known to be associated with neurodevelopment disorders ranging from benign familial neonatal infantile seizures (BFIS) to developmental and epileptic encephalopathy (DEE) and autism spectrum disorder. Interestingly, status epilepticus during slow sleep (ESES), which aggravates cognitive impairment, has been found in SCN2A-related epilepsy. However, the functional features and the relationship between SCN2A and ESES have not been researched.

Method: We herein investigated the functional consequences of an unpublished de novo V911A and the other two published variants in patients with SCN2A-related disorder and ESES by whole-cell patch-clamp studies in transfected HEK293T cells.

Results: The unpublished V911A and published K1933M variants detected in patients with DEE exhibited a profound gain-of-functional (GOF) change. Another published BFIS variant S863F significantly reduced current density as a loss-of-functional (LOF) change. The refractory epilepsy in the patient with V911A was controlled by using the precise treatment of oxcarbazepine (OXC) since the age of 3 months. ESES was found at 18 months during the seizure-free period. We finally chose an aggressive treatment for eliminating ESES by using methylprednisolone combined with levetiracetam and nitrazepam instead of the precise treatment of OXC.

Conclusion: Both GOF and LOF variants in the SCN2A gene can lead to ESES among the phenotypes of DEE and BFIS. We should monitor the electroencephalogram regularly in the patients with SCN2A-related epilepsy even during their seizure-free period.

Treatment Practices and Outcomes in Continuous Spike and Wave during Slow Wave Sleep: A Multicenter Collaboration

OBJECTIVES

To determine how continuous spike and wave during slow wave sleep (CSWS) is currently managed and to compare the effectiveness of current treatment strategies using a database from 11 pediatric epilepsy centers in the US.

STUDY DESIGN

This retrospective study gathered information on baseline clinical characteristics, CSWS etiology, and treatment(s) in consecutive patients seen between 2014 and 2016 at 11 epilepsy referral centers. Treatments were categorized as benzodiazepines, steroids, other antiseizure medications (ASMs), or other therapies. Two measures of treatment response (clinical improvement as noted by the treating physician; and electroencephalography improvement) were compared across therapies, controlling for baseline variables.

RESULTS

Eighty-one children underwent 153 treatment trials during the study period (68 trials of benzodiazepines, 25 of steroids, 45 of ASMs, 14 of other therapies). Children most frequently received benzodiazepines (62%) or ASMs (27%) as first line therapy. Treatment choice did not differ based on baseline clinical variables, nor did these variables correlate with outcome. After adjusting for baseline variables, children had a greater odds of clinical improvement with benzodiazepines (OR 3.32, 95%CI 1.57-7.04, P = .002) or steroids (OR 4.04, 95%CI 1.41-11.59, P = .01) than with ASMs and a greater odds of electroencephalography improvement after steroids (OR 3.36, 95% CI 1.09-10.33, P = .03) than after ASMs.

CONCLUSIONS

Benzodiazepines and ASMs are the most frequent initial therapy prescribed for CSWS in the US. Our data suggests that ASMs are inferior to benzodiazepines and steroids and support earlier use of these therapies. Multicenter prospective studies that rigorously assess treatment protocols and outcomes are needed.

Genetic Etiologies in Developmental and/or Epileptic Encephalopathy With Electrical Status Epilepticus During Sleep: Cohort Study

Background

Recently, the electroencephalogram pattern of electrical status epilepticus during sleep (ESES) had been reported in some genetic disorders, and most of them were noted with developmental and epileptic encephalopathy (DEE) or epileptic encephalopathy (EE). This study aimed to determine the genetic etiologies and clinical characteristics of ESES in DEE/EE.

Methods

We performed a cohort study in cases of DEE or EE with ESES. Tio-based genetic testing was performed in 74 cases and was analyzed to identify underlying variants.

Results

Pathogenic or likely pathogenic variants were identified in 17/74 cases, including KCNQ2 (n = 6), KCNA2 (n = 5), GRIN2A (n = 3), SLC9A6 (n = 1), HIVEP2 (n = 1), and RARS2 (n = 1). Eleven were boys. The median age at seizure onset was 6 months. ESES occurred at the mean age of 2.0 ± 1.2 years, predominant in the Rolandic region in 14 years. Twelve of 17 cases had the first stage of different epilepsy preceding ESES: 2/12 were diagnosed as Ohtahara syndrome, 2/12 were diagnosed as infantile spasms, 3/12 were diagnosed as DEE, and 5/12 were diagnosed as EE without the epileptic syndrome.

Conclusion

Monogenic variants explained over 20% of DEE/EE with ESES. ESES could be an age-related feature in genetic disorders and occurred after the first stage of different epilepsy. Both age-related factors and genetic etiology were suggested to play a role in the occurrence of ESES in genetic DEE/EE.

Electrical Status Epilepticus During Slow-wave Sleep (ESES): Current Perspectives

Electrical status epilepticus during slow-wave sleep (ESES) is an epilepsy syndrome with sleep-induced epileptic discharges and acquired impairment of cognition or behavior. Since the disease’s original description in 1971, no clear consensus has emerged on diagnostic criteria or optimal treatment. The treatment of ESES can be challenging, often including numerous antiepileptic drugs, immunomodulatory agents, and even surgical interventions. There is little evidence to guide treatment because only retrospective studies and case reports on the efficacy of treatment of ESES are present in literature. In this paper, we aim to analyze the etiopathogenesis of ESES in the new genetic era and to evaluate the treatment modalities in accordance with the genetic data and electroclinic spectrum of ESES.

Focal Sleep Spindle Deficits Reveal Focal Thalamocortical Dysfunction and Predict Cognitive Deficits in Sleep Activated Developmental Epilepsy

Childhood epilepsy with centrotemporal spikes (CECTS) is the most common focal epilepsy syndrome, yet the cause of this disease remains unknown. Now recognized as a mild epileptic encephalopathy, children exhibit sleep-activated focal epileptiform discharges and cognitive difficulties during the active phase of the disease. The association between the abnormal electrophysiology and sleep suggests disruption to thalamocortical circuits. Thalamocortical circuit dysfunction resulting in pathologic epileptiform activity could hinder the production of sleep spindles, a brain rhythm essential for memory processes. Despite this pathophysiologic connection, the relationship between spindles and cognitive symptoms in epileptic encephalopathies has not been previously evaluated. A significant challenge limiting such work has been the poor performance of available automated spindle detection methods in the setting of sharp activities, such as epileptic spikes. Here, we validate a robust new method to accurately measure sleep spindles in patients with epilepsy. We then apply this detector to a prospective cohort of male and female children with CECTS with combined high-density EEGs during sleep and cognitive testing at varying time points of disease. We show that: (1) children have a transient, focal deficit in spindles during the symptomatic phase of disease; (2) spindle rate anticorrelates with spike rate; and (3) spindle rate, but not spike rate, predicts performance on cognitive tasks. These findings demonstrate focal thalamocortical circuit dysfunction and provide a pathophysiological explanation for the shared seizures and cognitive symptoms in CECTS. Further, this work identifies sleep spindles as a potential treatment target of cognitive dysfunction in this common epileptic encephalopathy.SIGNIFICANCE STATEMENT Childhood epilepsy with centrotemporal spikes is the most common idiopathic focal epilepsy syndrome, characterized by self-limited focal seizures and cognitive symptoms. Here, we provide the first evidence that focal thalamocortical circuit dysfunction underlies the shared seizures and cognitive dysfunction observed. In doing so, we identify sleep spindles as a mechanistic biomarker, and potential treatment target, of cognitive dysfunction in this common developmental epilepsy and provide a novel method to reliably quantify spindles in brain recordings from patients with epilepsy.

High genetic burden in 163 Chinese children with status epilepticus

PURPOSE

This study aimed to investigate the genetic aetiology in Chinese children diagnosed with status epilepticus (SE).

METHODS

Next-generation sequencing, copy number variation (CNV) analysis, and other genetic testing methods were conducted for children with SE lacking an identifiable non-genetic aetiology. Furthermore, the phenotype and molecular data of patients with SE were retrospectively analysed.

RESULTS

Among children with SE lacking an identifiable non-genetic aetiology, 73 out of 163 children (44.8 %) were found to have causative variants associated with SE including 66 monogenic mutations in 22 genes and 7 CNVs. Based on the American College of Medical Genetics and Genomics scoring system, the monogenic variants included 64 pathogenic/likely pathogenic and 2 uncertain significance variants. SCN1A gene mutations (n = 32) were the most common cause, followed by TSC2 (n = 5), CACNA1A (n = 5), SCN2A (n = 4), SCN9A (n = 2) and DEPDC5 (n = 2) gene mutations. Sixteen mutations were identified in single genes. Furthermore, 51 (77.3 %) monogenic mutations were de novo. Age at SE onset < 1 year (odds ratio [OR] = 2.70, 95 % confidence interval [CI]: 1.25-5.83, p = 0.012) and co-morbidity of intellectual disability (OR = 3.36, 95 %CI: 1.61-6.99, p = 0.001) were independently associated with pathogenic genetic variants.

CONCLUSION

This study identified genetic aetiology in 44.8 % of patients with SE, which indicates a high burden of genetic aetiology among children with SE in China. Our findings highlight the importance for genetic testing of children with SE that lacks an identifiable non-genetic aetiology.

Continuous epileptic negative myoclonus as the first seizure type in atypical benign epilepsy with centrotemporal spikes

To figure out which diagnosis is more suitable and which antiepileptic drugs are more sensitive to epileptic negative myoclonus (ENM) as the first seizure type in atypical benign epilepsy with centrotemporal spikes.We reviewed the electroencephalogram (EEG) database of Linyi People's Hospital Affiliated to Shandong University and medical records of patients with ENM onset. The characteristics of epileptic seizures, onset age, treatment process, growth and development history, past disease history, family history, degree of mental deterioration, cranial imaging, and video-EEG were studied retrospectively and followed up.There were 4 cases with ENM onset and 1 with continuous ENM, 3 males and 1 female. The onset age was from 2 years 3 months to 8 years 7 months. The cranial magnetic resonance imaging (MRI) and developmental quotient, as well as the family, personal, and past disease history, were normal. Frequent falls and drops were the main clinical manifestations. Five months after the onset of ENM, case 1 had focal seizures in sleep. ENM was the first and only manifestation in all the other 3 children. Discharges of interictal EEG were in bilateral rolandic areas, especially in midline areas (Cz, Pz), electrical status epilepticus in sleep was found in 3 cases. One child was sensitive to levetiracetam, the other 3 were sensitive to clonazepam.ENM can affect the upper or lower extremities. ENM as the first or only symptom was a special phenomenon in benign epilepsy with centrotemporal spikes (BECTS) variants. Ignorance of midline spikes mainly in Cz or Pz in BECTS might lead to missed diagnosis of ENM. Whether benzodiazepines are viable as a choice of BECTS variants with electrical status epilepticus in sleep when ENM is the first symptom still needs a large sample evidence-based observation.

Sleep and Epilepsy Link by Plasticity

We aimed to explore the link between NREM sleep and epilepsy. Based on human and experimental data we propose that a sleep-related epileptic transformation of normal neurological networks underlies epileptogenesis. Major childhood epilepsies as medial temporal lobe epilepsy (MTLE), absence epilepsy (AE) and human perisylvian network (PN) epilepsies - made us good models to study. These conditions come from an epileptic transformation of the affected functional systems. This approach allows a system-based taxonomy instead of the outworn generalized-focal classification. MTLE links to the memory-system, where epileptic transformation results in a switch of normal sharp wave-ripples to epileptic spikes and pathological high frequency oscillations, compromising sleep-related memory consolidation. Absence epilepsy (AE) and juvenile myoclonic epilepsy (JME) belong to the corticothalamic system. The burst-firing mode of NREM sleep normally producing sleep-spindles turns to an epileptic working mode ejecting bilateral synchronous spike-waves. There seems to be a progressive transition from AE to JME. Shared absences and similar bilateral synchronous discharges show the belonging of the two conditions, while the continuous age windows - AE affecting schoolchildren, JME the adolescents - and the increased excitability in JME compared to AE supports the notion of progression. In perisylvian network epilepsies - idiopathic focal childhood epilepsies and electrical status epilepticus in sleep including Landau-Kleffner syndrome - centrotemporal spikes turn epileptic, with the potential to cause cognitive impairment. Postinjury epilepsies modeled by the isolated cortex model highlight the shared way of epileptogenesis suggesting the derailment of NREM sleep-related homeostatic plasticity as a common step. NREM sleep provides templates for plasticity derailing to epileptic variants under proper conditions. This sleep-origin explains epileptiform discharges' link and similarity with NREM sleep slow oscillations, spindles and ripples. Normal synaptic plasticity erroneously overgrowing homeostatic processes may derail toward an epileptic working-mode manifesting the involved system's features. The impact of NREM sleep is unclear in epileptogenesis occurring in adolescence and adulthood, when plasticity is lower. The epileptic process interferes with homeostatic synaptic plasticity and may cause cognitive impairment. Its type and degree depends on the affected network's function. We hypothesize a vicious circle between sleep end epilepsy. The epileptic derailment of normal plasticity interferes with sleep cognitive functions. Sleep and epilepsy interconnect by the pathology of plasticity.

Resolution of EEG findings and clinical improvement in a patient with encephalopathy and ESES with a combination of immunomodulating agents other than corticosteroids: A case report

Encephalopathy with electrical status epilepticus in sleep (ESES) syndrome is characterized by a near-continuous spike-and-wave discharges during sleep with marked developmental regression, mainly in speech, and the presence of clinical seizures. Although the etiology ofESES is generally unknown, its resistance to antiseizure medication (ASM), and favorable responses to oral corticosteroids (OCS), support a role for inflammation. However, the prolonged use of OCS results in undesirable side effects and alternative treatment measures are needed. Herein, we present a patient with ESES who revealed responsed to a combination of immunomodulating agents other than OCS. The patient revealed 30, 50, and 100%, reduction in the ESES pattern on EEG with the sequential addition of anakinra (interleukin-1ß inhibitor), intravenous immunoglobulin (IVIg), and sirolimus, an inhibitor of mammalian target of rapamycin (mTOR) respectively, after discontinuation of OCS due to side effects. This combination of immune-modulating agents, that were selected based on monocyte cytokine profiles, also resulted in a gradual improvement of speech and behavioral symptoms. This case indicates a possible use of immunomodulating agents other than OCS for ESES syndrome.

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ESES syndrome can be controlled immunomodulating agents.

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OCS was not requred for maintaing good control of ESES in the presented case.

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Monocyte cytokine profiles may be useful for the selection of immunomodulating agents for treatment of ESES.

A Novel WAC Loss of Function Mutation in an Individual Presenting with Encephalopathy Related to Status Epilepticus during Sleep (ESES)

WAC (WW Domain Containing Adaptor With Coiled-Coil) mutations have been reported in only 20 individuals presenting a neurodevelopmental disorder characterized by intellectual disability, neonatal hypotonia, behavioral problems, and mildly dysmorphic features. Using targeted deep sequencing, we screened a cohort of 630 individuals with variable degrees of intellectual disability and identified five WAC rare variants: two variants were inherited from healthy parents; two previously reported de novo mutations, c.1661_1664del (p.Ser554*) and c.374C>A (p.Ser125*); and a novel c.381+2T>C variant causing the skipping of exon 4 of the gene, inherited from a reportedly asymptomatic father with somatic mosaicism. A phenotypic evaluation of this individual evidenced areas of cognitive and behavioral deficits. The patient carrying the novel splicing mutation had a clinical history of encephalopathy related to status epilepticus during slow sleep (ESES), recently reported in another WAC individual. This first report of a WAC somatic mosaic remarks the contribution of mosaicism in the etiology of neurodevelopmental and neuropsychiatric disorders. We summarized the clinical data of reported individuals with WAC pathogenic mutations, which together with our findings, allowed for the expansion of the phenotypic spectrum of WAC-related disorders.

New phenotypes associated with 3q29 duplication syndrome: Results from the 3q29 registry

3q29 duplication syndrome (3q29dup) is a rare genomic disorder caused by a 1.6 Mb duplication (GRCh38 chr3:195,998,000-197,623,000). Case reports indicate the 3q29dup is likely to be pathogenic, but the full range of manifestations is not well understood. We used the 3q29 registry (https://3q29.com) to ascertain 31 individuals with 3q29dup, the largest cohort ever surveyed in a systematic way. For comparison, we ascertained 117 individuals with the reciprocal 3q29 deletion and 64 typically developing controls. We used a custom medical and demographic questionnaire to assess physical and developmental phenotypes, and two standardized instruments, the Social Responsiveness Scale and Child Behavior Checklist/Adult Behavior Checklist, to assess social disability. Participants with 3q29dup report a high rate of problems in the first year of life (80.6%), including feeding problems (55%), failure to gain weight (42%), hypotonia (39%), and respiratory distress (29%). In early childhood, learning problems (71.0%) and seizures (25.8%) are common. Additionally, the rate of self-reported autism spectrum disorder diagnoses (39%) is substantially elevated compared to the general population, suggesting that the 3q29 duplication may be an autism susceptibility locus. This is the most comprehensive description of 3q29dup to date. Our findings can be used to develop evidence-based strategies for early intervention and management of 3q29dup.

Expanding the clinical and EEG spectrum of CNKSR2-related encephalopathy with status epilepticus during slow sleep (ESES)

OBJECTIVE

To investigate the clinical and EEG features of Encephalopathy with Status Epilepticus during slow Sleep (ESES) related to CNKSR2 pathogenic variants.

METHODS

Detailed clinical history, repeated wakefulness/overnight sleep EEGs, brain MRI were collected in five patients, including one female, with CNKSR2-related ESES.

RESULTS

Neurodevelopment in infancy was normal in two patients, delayed in three. Epilepsy onset (age range: 2-6 years) was associated with appearance or aggravation of cognitive impairment, language regression and/or behavioral disorders. Worsening of epilepsy and of cognitive/behavioral disturbances paralleled by enhancement of non-rapid eye movement (NREM) sleep-related, frontally predominant, EEG epileptic discharges [spike-wave-index (SWI): range 60-96%] was consistent with ESES. In three patients, episodes of absence status epilepticus or aggravation of atypical absences occurred, in this latter case associated with striking increment of awake SWI. Speech/oro-motor dyspraxia was diagnosed in four patients. In two patients, long-term follow-up showed epilepsy remission and persistence of mild/moderate cognitive disorders and behavioral disturbances into adulthood.

CONCLUSIONS

Novel findings of our study are occurrence also in females, normal neurodevelopment before epilepsy onset, epilepsy aggravation associated with enhanced awake SWI, mild/moderate evolution in adulthood and language disorder due to speech/oro-motor dyspraxia.

SIGNIFICANCE

Our findings expand the phenotypic spectrum of CNKSR2-related ESES.

The role of sleep-related cognitive functions in the spectrum of benign epilepsy with centro-temporal spikes

Heterogeneous cognitive deficits have been described in the spectrum of benign epilepsy with centro-temporal spikes, which strongly correlate with the intensity of interictal epileptiform discharges and its spreading, in particular during sleep, mostly within the perisylvian cognitive network. The aim of this review is to discuss current findings regarding the connection between sleep alterations and cognitive function in the spectrum of benign epilepsy with centro-temporal spikes. A longer sleep onset latency is the only evident sleep macrostructure alteration reported in the spectrum of benign epilepsy with centro-temporal spikes. On a microstructural level, a higher spike count of descending compared to ascending slopes of sleep cycles, an impairment of slow wave downscaling, and amplitude and slope of slow waves were found in the spectrum of benign epilepsy with centro-temporal spikes. Moreover, children with benign epilepsy with centro-temporal spikes had a reduced non-rapid eye movement sleep instability, in terms of cyclic alternating pattern, similar to that found in children with attention-deficit hyperactivity disorders and in children with obstructive sleep apnea and centro-temporal spike during sleep. Children with benign epilepsy with centro-temporal spikes have a known comorbidity with attention-deficit hyperactivity disorders and obstructive sleep apnea.Conclusion: Considering the common sleep microstructure alterations, the presence of attention deficit and hyperactivity and/or sleep apnea may be a considered warning sign in the case of benign epilepsy with centro-temporal spikes. What is Known: • Sleep related-cognitive deficits have been described in the spectrum of benign epilepsy with centro-temporal spikes. The degree of sleep alterations may predict the neurocognitive outcome, and help clinicians to choose the right treatment. What is New: • Considering the common sleep microstructure alterations, attention deficit and sleep apnea, may be a considered warning signs.

Levels of Melatonin in Continuous Spikes and Waves During Sleep

Levels of melatonin have been reported before in children with epilepsy, but such has not been reported to date in those with continuous spikes and waves during sleep. The aim of the present study was to assess serum melatonin levels and melatonin circadian rhythm in patients with continuous spikes and waves during sleep and epilepsy. Serum melatonin was measured in 39 children stratified into 3 groups. Group 1 included 15 patients with continuous spikes and waves during sleep, group 2 included 12 epilepsy patients, and group 3 included 12 controls, respectively. Blood samples were taken from all participants at 1:00 am and 9:00 am and melatonin levels were measured using a quantitative enzyme-linked immunosorbent assay test. The 9:00 am melatonin levels of group 1 were significantly decreased and pair groups were compared. The P_a value (representing a comparison between groups 1 and 2) was .002, the P_b value (representing a comparison between groups 1 and 3) was .001, and the P_c value (representing a comparison between groups 2 and 3) was .86. These findings suggest that the 9:00 am melatonin levels were significantly decreased in the comparison of groups 2 and 3. Further detailed research is necessary to determine the factors leading to the rapid decline of morning melatonin levels of children with continuous spikes and waves during sleep.

[A clinical analysis of electrical status epilepticus during sleep in children and a follow-up study of methylprednisolone pulse therapy]

OBJECTIVE

To study the clinical features of electrical status epilepticus during sleep (ESES) in children, as well as the clinical effect of methylprednisolone pulse therapy in children with ESES.

METHODS

A retrospective analysis was performed using the clinical data of 78 children with ESES. Among these children, 56 children who had had the failure of antiepileptic drugs were treated with methylprednisolone pulse therapy at a dose of 15-20 mg/(kg·d) for three courses. Each course of treatment was 3 days, followed by oral prednisone [1-2 mg/(kg·d)] for 3 days. The role of methylprednisolone pulse therapy in eliminating ESES, controlling clinical seizures, and improving intelligence and behaviors was analyzed.

RESULTS

The mean age of onset of epilepsy in 78 children was 6.8±2.4 years, and the mean age for the first occurrence of ESES was 7.6±2.5 years. Compared with normal children, children with ESES had delayed intelligence development and higher scores of some behavior problems. Methylprednisolone pulse therapy had an overall response rate of 73% (41/56) on clinical seizures, and the overall response rate on electroencephalography (EEG)/spike-wave index was 70% (39/56) after treatment. There were significant improvements in verbal intelligence quotient, performance intelligence quotient and full intelligence quotient, and significant reductions in the scores of learning problems, impulse-hyperactivity and hyperactivity index after treatment (P<0.05). The overall recurrence rate after 1-year follow-up was 29% (11/38).

CONCLUSIONS

ESES often presents around school age and impairs children's intelligence and behaviors. Methylprednisolone pulse therapy has a marked efficiency in reducing clinical seizures and EEG discharges in children with ESES and can improve intelligence and behavior development, but the recurrence rate remains high.

CNKSR2 mutation causes the X-linked epilepsy-aphasia syndrome: A case report and review of literature

The mutation in CNKSR2 leads to a broad spectrum of phenotypic variability and manifests as an X-linked intellectual disability. However, we reported that the male patient in this study not only had intellectual disability but also epileptic seizures. In addition, there were progressive language impairment, attention deficit hyperactivity disorder and autism. Electroencephalograms showed continuous spike-and-wave during sleep. Genetic testing revealed a de novo mutation of the CNKSR2 gene (c.2185C>T, p.Arg729Ter) in the child that was not detected in the parents. Therefore, the child was diagnosed with X-linked epilepsy aphasia syndrome. Deletion of the CNKSR2 gene has been rarely reported in epilepsy aphasia syndrome, but no de novo mutation has been found in this gene. This report not only adds to the spectrum of epilepsy aphasia syndrome but also helps clinicians in diagnosis and genetic counseling.