Neonatal SCN2A encephalopathy: A peculiar recognizable electroclinical sequence

Experience with the ketogenic diet in premature neonates

The ketogenic diet is a time-tested, potent, nonpharmacological treatment of epilepsy. However, the use of the ketogenic diet in premature neonates with epilepsy has not been previously reported. We share our experience with the use of ketogenic diet therapy in two premature neonates. Two identical twin premature neonates with SCN2A-related developmental and epileptic encephalopathy, whose seizures were refractory to multiple anti-seizure medications, were started on the classic ketogenic diet at the conceptual age of 35 weeks. Ketosis was achieved and maintained (range 2-5 mmol/L of serum beta-hydroxybutyrate level). Seizure frequency was significantly reduced (>90% reduction in both patients), and some anti-seizure medications were able to be discontinued. Initial transient weight loss and one episode of asymptomatic hypoglycemia were observed and corrected. The ketogenic diet was found to be a safe, well-tolerated, and effective treatment for seizures in two premature neonates. The side effects are tolerable and correctable. The ketogenic diet, therefore, is a treatment option for refractory seizures in this age group, when administered under expert guidance.

Sleep architecture in neonatal and infantile onset epilepsies in the first six months of life: A scoping review

AIM

Epilepsy occurs in approximately 80 per 100,000 infants in the first year of life, ranging in severity from self-limited and likely to spontaneously resolve, to severe developmental and epileptic encephalopathies. Sleep plays a key role in early brain development and the reciprocal relationship between sleep and seizures is not yet fully understood, particularly in young children. We conducted a Scoping Review to synthesise current knowledge of sleep architecture in neonates and infants with epilepsy.

METHOD

Peer-reviewed publications from 2005 to 2022 describing sleep architecture in infants up to six months of age with unprovoked seizures were included. The analysis set was derived from EMBASE, Web of Science and PubMED using key terms "sleep, epilepsy and infant" and related descriptors. Inclusion criteria were prospectively described in a Scoping Review protocol. Sleep architecture was assessed as macro- and micro-structural elements.

RESULTS

21 publications were included in the qualitative analysis. In self-limited familial and genetic epilepsy, sleep macrostructure was generally preserved. In DEEs and in epileptic encephalopathies of genetic or structural aetiology, sleep architecture was significantly disrupted.

INTERPRETATION

Early identification of infants with epilepsy is important to ensure early and effective treatment. In the DEE spectrum, sleep architecture is significantly impacted, and abnormal sleep architecture may be associated with compromised developmental outcome. Further research is needed to identify the sequence of events in abnormal brain development, epilepsy and sleep disruption and potentially help to predict the course of epilepsy towards a self-limited epilepsy versus a DEE.

SCN2A-Related Epilepsy: The Phenotypic Spectrum, Treatment and Prognosis

OBJECTIVE

The aim of this study was to analyze the phenotypic spectrum, treatment, and prognosis of 72 Chinese children with SCN2A variants.

METHODS

The SCN2A variants were detected by next-generation sequencing. All patients were followed up at a pediatric neurology clinic in our hospital or by telephone.

RESULTS

In 72 patients with SCN2A variants, the seizure onset age ranged from the first day of life to 2 years and 6 months. The epilepsy phenotypes included febrile seizures (plus) (n = 2), benign (familial) infantile epilepsy (n = 9), benign familial neonatal-infantile epilepsy (n = 3), benign neonatal epilepsy (n = 1), West syndrome (n = 16), Ohtahara syndrome (n = 15), epilepsy of infancy with migrating focal seizures (n = 2), Dravet syndrome (n = 1), early infantile epileptic encephalopathy (n = 15), and unclassifiable developmental and epileptic encephalopathy (n = 8). Approximately 79.2% (57/72) patients had varying degrees of developmental delay. All patients had abnormal MRI findings with developmental delay. 91.7% (55/60) patients with de novo SCN2A variants had development delay, while only 16.7% (2/12) patients with inherited SCN2A variants had abnormal development. 83.9% (26/31) SCN2A variants that were located in transmembrane regions of the protein were detected in patients with development delay. Approximately 69.2% (9/13) SCN2A variants detected in patients with normal development were located in the non-transmembrane regions. Approximately 54.2% (39/72) patients were seizure-free at a median age of 8 months. Oxcarbazepine has been used by 38 patients, and seizure-free was observed in 11 of them (11/38, 28.9%), while 6 patients had seizure worsening by oxcarbazepine. All 3 patients used oxcarbazepine and with seizure onset age > 1 year presented seizure exacerbation after taking oxcarbazepine. Valproate has been used by 53 patients, seizure-free was observed in 22.6% (12/53) of them.

CONCLUSION

The phenotypic spectrum of SCN2A-related epilepsy was broad, ranging from benign epilepsy in neonate and infancy to severe epileptic encephalopathy. Oxcarbazepine and valproate were the most effective drugs in epilepsy patients with SCN2A variants. Sodium channel blockers often worsen seizures in patients with seizure onset beyond 1 year of age. Abnormal brain MRI findings and de novo variations were often related to poor prognosis. Most SCN2A variants located in transmembrane regions were related to patients with developmental delay.

Approach to Neurological Channelopathies and Neurometabolic Disorders in Newborns

Ion channel disorders (channelopathies) can affect any organ system in newborns before 2 months of life, including the skeletal muscle and central nervous system. Channelopathies in newborns can manifest as seizure disorders, which is a critical issue as early onset seizures can mimic the presentation of neurometabolic disorders. Seizures in channelopathies can either be focal or generalized, and range in severity from benign to epileptic encephalopathies that may lead to developmental regression and eventually premature death. The presenting symptoms of channelopathies are challenging for clinicians to decipher, such that an extensive diagnostic survey through a precise step-by-step process is vital. Early diagnosis of a newborn's disease, either as a channelopathy or neurometabolic disorder, is important for the long-term neurodevelopment of the child.

The role of new medical treatments for the management of developmental and epileptic encephalopathies: Novel concepts and results

Developmental and epileptic encephalopathies (DEEs) are among the most challenging of all epilepsies to manage, given the exceedingly frequent and often severe seizure types, pharmacoresistance to conventional antiseizure medications, and numerous comorbidities. During the past decade, efforts have focused on development of new treatment options for DEEs, with several recently approved in the United States or Europe, including cannabidiol as an orphan drug in Dravet and Lennox-Gastaut syndromes and everolimus as a possible antiepileptogenic and precision drug for tuberous sclerosis complex, with its impact on the mammalian target of rapamycin pathway. Furthermore, fenfluramine, an old drug, was repurposed as a novel therapy in the treatment of Dravet syndrome. The evolution of new insights into pathophysiological processes of various DEEs provides possibilities to investigate novel and repurposed drugs and to place them into the context of their role in future management of these patients. The purpose of this review is to provide an overview of these new medical treatment options for the DEEs and to discuss the clinical implications of these results for improved treatment.

Three different scenarios for epileptic spasms

Epileptic Spasms (ES) is a type of seizure usually occurring in the context of a severe childhood epileptic syndrome associated to significant Electroencephalogram (EEG) abnormalities. There are three scenarios in which ES may occur. The first one is represented by West Syndrome (WS): ES occur in a previously non encephalopathic infant in association with the development of a hypsarrhythmic EEG pattern. In most cases, standard treatment with Adrenocorticotropic Hormone (ACTH), steroids or vigabatrin leads to a reversal of the electroclinical picture. The second scenario is represented by Developmental and Epileptic Encephalopathies (DEEs): ES are documented, often along other seizures types, in an infant who often shows developmental delay since birth; the EEG pattern is pathological both in wakefulness and in sleep, without typical features of hypsarrhythmia; therapies (with the exception of few potentially treatable syndromes) are poorly effective. The last scenario is represented by ES in the context of Focal Epilepsies (FEs): ES, sometimes showing focal signs or closely related to focal seizures, are associated with focal brain lesions. Treatment with ACTH, steroids or vigabatrin may not be effective as well as antiepileptic drugs for focal epilepsies. In drug-resistant patients, surgery should be considered. Although there are some gaps in our current scientific knowledge concerning the peculiar electroclinical and physiopathological features of ES, we nowadays possess the necessary tools to correctly frame this unique seizure type into one of these scenarios and therefore properly manage the diagnostic and therapeutic workup.