Genotype and phenotype spectrum of 10 children with STXBP1 gene-related encephalopathy and epilepsy

Management of Developmental and Epileptic Encephalopathies

Developmental and epileptic encephalopathies (DEEs) are a group of rare, severe, early-onset epilepsies characterized by pharmacoresistance, marked electroencephalographic abnormalities, and delayed or regressive psychomotor development. DEEs are associated with poor long-term outcomes and increased mortality; however, early recognition and targeted treatment can impact neurodevelopmental outcomes and overall quality of life. Treatment with antiseizure medication is often challenging given drug resistance, chronic polypharmacy, and medication interactions. With advances in genetic testing and increased understanding of the neurobiological mechanisms of DEEs, the treatment approach is evolving and includes repurposed antiseizure medications and targeted therapies, as well as early surgical intervention in select patients. In addition to high seizure burden and neurodevelopmental delay, DEEs are associated with comorbidities affecting a range of body systems; these can include intellectual disability, psychiatric disorders, motor dysfunction, and respiratory and gastrointestinal problems. Over time, these comorbidities increase the complexity of management and have important implications on the disease burden and quality of life for both patients and their caregivers. Multidisciplinary care in DEEs is paramount. We summarize the current evidence on the management of specific DEEs, focusing on targeted therapies and optimizing outcomes.

Case reports of identical twins with developmental and epileptic encephalopathy with STXBP1 gene mutations for whom different CBD supplementations were markedly effective

Cannabidiol (CBD) is a compound found specifically in the cannabis plant. Although a clinical trial for intractable epilepsy started in Japan in 2023, it is also available in the market as a dietary supplement. Herein, we report two cases of identical twins with developmental and epileptic encephalopathy with STXBP1 gene mutation who achieved seizure suppression through different regimens of CBD supplementation. The observation that different trace ingredients produced different effects in patients with identical genetic backgrounds is a crucial finding that has implications for the future regulation and clinical application of cannabinoid products.

Surgical outcomes of patients with genetically refractory epilepsy: A systematic review and meta-analysis

OBJECTIVE

To summarize the surgical outcomes of genetically refractory epilepsy and identify prognostic factors for these outcomes.

METHODS

A literature search of the PubMed, Web of Science, and Embase databases for relevant studies, published between January 1, 2002 and December 31, 2023, was performed using specific search terms. All studies addressing surgical outcomes and follow-up of genetically refractory epilepsy were included. All statistical analyses were performed using STATA software (StataCorp LLC, College Station, TX, USA). This review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, 2020 (i.e., "PRISMA") reporting guidelines.

RESULTS

Of the 3833 studies retrieved, 55 fulfilled the inclusion criteria. Eight studies were eligible for meta-analysis at the study level. Pooled outcomes revealed that 74 % of patients who underwent resective surgery (95 % confidence interval [CI] 0.55-0.89; z = 9.47, p < 0.05) achieved Engel I status at the last follow-up. In the study level analysis, pooled outcomes revealed that 9 % of patients who underwent vagus nerve stimulation achieved seizure-free status (95 % CI 0.00-0.31; z = 1.74, p < 0.05), and 61 % (95 % CI 0.55-0.89; z = 11.96, p < 0.05) achieved a 50 % reduction in seizure frequency at the last follow-up. Fifty-three studies comprising 249 patients were included in an individual-level analysis. Among patients who underwent lesion resection or lobectomy/multilobar resection, 65 % (100/153) achieved Engel I status at the last follow-up. Univariate analysis indicated that female sex, somatic mutations, and presenting with focal seizure symptoms were associated with better prognosis (p < 0.05). Additionally, 75 % (21/28) of patients who underwent hemispherectomy/hemispherotomy achieved Engel I status at the last follow-up. In the individual-level analysis, among patients treated with vagus nerve stimulation, 21 % (10/47) were seizure-free and 64 % (30/47) experienced >50 % reduction in seizure frequency compared with baseline.

CONCLUSION

Meticulous presurgical evaluation and selection of appropriate surgical procedures can, to a certain extent, effectively control seizures. Therefore, various surgical procedures should be considered when treating patients with genetically refractory epilepsy.

STXBP1-Related Disorders: Clinical Presentation, Molecular Function, Treatment, and Future Directions

In recent years, the affordability and availability of genetic testing have led to its increased use in clinical care. The increased frequency of testing has led to STXBP1 variants being identified as one of the more common variants associated with neurological disorders. In this review, we aim to summarize the common clinical phenotypes associated with STXBP1 pathogenic variants, provide an overview of their known natural history, and discuss current research into the genotype to phenotype correlation. We will also provide an overview of the suspected normal function of the STXBP1-encoded Munc18-1 protein, animal models, and experimental techniques that have been developed to study its function and use this information to try to explain the diverse phenotypes associated with STXBP1-related disorders. Finally, we will explore current therapies for STXBP1 disorders, including an overview of treatment goals for STXBP1-related disorders, a discussion of the current evidence for therapies, and future directions of personalized medications for STXBP1-related disorders.