Efficacy of vagus nerve stimulation in 95 children of drug-resistant epilepsy with structural etiology.

Vagus nerve stimulation (VNS) is one of the treatment options for drug-resistant epilepsy (DRE). To analyze the efficacy of VNS in children of DRE with structural etiology, we conducted a cohort study including 95 patients of DRE with structural etiology who underwent VNS treatment. Patients were followed up every 3 months at the outpatient department or via a remote programming platform. The median follow-up period was 2.6 years (range 1.0-4.6 years). The respective responder rates at 6, 12, 18, and 24 months of follow-up were 40.0% (38/95), 52.6% (50/95), 56.0% (47/84), and 59.7% (37/62). The respective seizure-free rates at 12, 18, and 24 months of follow-up were 8.4% (8/95), 9.5% (8/84), and 9.7% (6/62). The patients were divided into four groups based on etiologies: malformations of cortical development (n = 26), post-encephalitic lesions (n = 36), perinatal brain injury lesions (n = 31), and hippocampal sclerosis (n = 2). The respective responder rates at 12 months of follow-up in these groups were 53.8% (14/26), 52.8% (19/36), 51.6% (16/31), and 50.0% (1/2). There were no significant differences in gender, age at onset, age at stimulator implantation, epilepsy duration prior to VNS implantation, number of anti-seizure medications ever tried before VNS treatment, pulse amplitude of VNS, specific structural etiologies, lobe distribution or hemispheric side of structural lesions between responders and non-responders. Of the 95 patients, 8 (8.4%) underwent lesion surgery or hemispherectomy before VNS implantation, and 6/8 (75%) of these patients had a >50% reduction in seizure frequency. One patient who had a corpus callosotomy before VNS implantation had no response to VNS treatment. In conclusion, VNS is an effective treatment in children of DRE with structural etiology. There was no significant difference in VNS efficacy in patients with different structural etiologies. Vagus nerve stimulation treatment may also control seizures well in some patients with poor outcomes after lesion resection or hemispherectomy before VNS implantation.

Genetic analysis of 20 patients with hypomyelinating leukodystrophy by trio-based whole-exome sequencing.

Hypomyelinating leukodystrophies (HLDs) are a rare group of disorders characterized by myelin deficit of the brain-based on MRI. Here, we studied 20 patients with unexplained HLD to uncover their genetic etiology through whole-exome sequencing (WES). Trio-based WES was performed for 20 unresolved HLDs families after genetic tests for the PLP1 duplication and a panel of 115 known leukodystrophy-related genes. Variants in both known genes that related to HLDs and promising candidate genes were analyzed. Minigene splicing assay was conducted to confirm the effect of splice region variant. All 20 patients were diagnosed with HLDs clinically based on myelin deficit on MRI and impaired motor ability. Through WES, in 11 of 20 trios, 15 causative variants were detected in seven genes TUBB4A, POLR1C, POLR3A, SOX10, TMEM106B, DEGS1, and TMEM63A. The last three genes have just been discovered. Of 15 variants, six were novel. Using minigene splicing assay, splice variant POLR3A c.1770 + 5 G > C was proved to disrupt the normal splicing of intron 13 and led to a premature stop codon at position 618 (p.(P591Vfs*28)). Our analysis determined the molecular diagnosis of 11 HLDs patients. It emphasizes the heterogenicity of HLDs, the diagnostic power of trio-based WES for HLDs. Comprehensive analysis including a focus on candidate genes helps to discover novel disease-causing genes, determine the diagnosis for the first time, and improve the yield of WES. Moreover, novel mutations identified in TUBB4A, POLR3A, and POLR1C expand the mutation spectrum of these genes.

Somatic variants in new candidate genes identified in focal cortical dysplasia type II.

OBJECTIVE: Focal cortical dysplasia type II (FCDII) is a malformation of cortex development commonly found in children with drug-resistant epilepsy. FCDII has been associated with somatic mutations in mammalian target of rapamycin (mTOR)-related pathway genes and an upregulation of mTOR. Somatic mutations were found in 10%-63% of FCDII samples; the frequency of the mutant allele was 0.93%-33.5%. This study aimed to find new candidate genes involved in FCDII. METHODS: We collected resected FCD lesions, perilesional brain tissues, and peripheral blood from 17 children with pathologically confirmed FCDII. We performed whole exome sequencing and followed a set of screening and analysis strategies to identify potentially deleterious somatic variants (PDSVs) in brain-expressed genes. We performed site-specific amplicon sequencing to validate the results. We also performed an in vitro functional study on an IRS1 variant. RESULTS: In six of 17 samples, we identified seven PDSVs in seven genes, including two frameshift variants and five missense variants. The frequencies of the variant allele were 1.29%-5.50%. The genes were MTOR, TSC2, IRS1, RAB6B, RALA, HTR6, and ZNF337. PDSVs in IRS1, RAB6B, ZNF337, RALA, and HTR6 had not been previously associated with FCD. In one lesion, two PDSVs were found in two genes. In a transfected cell line, we demonstrated that the c.1791dupG (identified in FCDII from Patient 1) led to a truncated IRS1 and significant mTOR hyperactivation compared to cells that carried wild-type IRS1. mTOR was also activated in FCDII tissue from Patient 1. SIGNIFICANCE: Seven PDSVs were identified in FCDII lesions in six of 17 children. Five variant genes had not been previously associated with cortical malformations. We demonstrated that the IRS1 variant led to mTOR hyperactivation in vitro. Although functional experiments are needed, the results provide evidence for novel candidate genes in the pathogenesis of FCDII.

Upregulation of HMGB1-TLR4 inflammatory pathway in focal cortical dysplasia type II.

BACKGROUND: We attempted to determine whether the inflammatory pathway HMGB1-TLR4 and the downstream pro-inflammatory cytokines is upregulated in focal cortical dysplasia (FCD) type II and whether there is a correlation between the TLR4 upregulation and disease duration or frequency of epileptic seizures. METHODS: FCD type II and peri-FCD paired tissues resected from eight children with refractory epilepsy were collected. Through real-time qPCR, Western blot, and co-immunoprecipitation, we examined the differences between FCD lesions and peri-FCD tissues with respect to mRNA expression, protein expression, and protein interaction in HMGB1-TLR4 pathway biomarker and downstream pro-inflammatory factors in whole brain tissue. Then, we used immunofluorescence to examine the difference between FCD lesions and peri-FCD tissues with respect to protein expression and intracellular distribution of HMGB1-TLR4 pathway biomarker in neurons, astrocytes, and oligodendrocytes. Correlation between level of TLR4 expression and disease duration or frequency of epileptic seizures in patients was also analyzed. RESULTS: The protein expression levels of TLR4, cytoplasm HMGB1, TLR4/MyD88 complex, ubiquitination of TRAF6, p-IKK, p-IκB-α, p-NF-κB p65, and IL-1ß and TNF-α in lesion tissues were significantly higher than those in peri-FCD controls. Total mRNA expression levels of TLR4, IL-1ß, and TNF-α in lesion tissues were significantly higher than those in peri-FCD controls, but HMGB1 had no significant change. In neurons and astrocytes inside the lesions, the expression of TLR4 protein was significantly higher than that in peri-FCD tissues, and HMGB1 was mainly expressed in the cytoplasm, while expressed in the nuclei in peri-FCD tissues. But in oligodendrocytes, there was no upregulation of HMGB1-TLR4 pathway in both lesions and peri-FCD tissues. We did not identify the correlation between the level of TLR4 activation and disease duration or frequency of epileptic seizures. CONCLUSION: The HMGB1-TLR4 pathway was upregulated in the neurons and astrocytes inside FCD type II lesions, which led to an increase in the release of downstream pro-inflammatory cytokines. Correlation between the level of TLR4 activation and duration or frequency of epileptic seizures was not identified.

[Surgery for pediatric intractable epilepsy due to posterior quadrantic cortical dysplasia].

OBJECTIVE: To investigate the clinical features and surgical strategy for pediatric intractable epilepsy due to posterior quadrantic cortical dysplasia and to assess the surgical outcomes. METHODS: The clinical features and preoperative evaluation results of 14 children with intractable epilepsy due to posterior quadrantic cortical dysplasia were retrospectively analyzed. The localization values of video-electroencephalography and intraoperative monitoring and the indications, advantages and disadvantages of temporoparietooccipital disconnection were evaluated. RESULTS: The 14 children had different seizure types, of which spasm was the most common one. The lesions of cortical dysplasia involved the central cerebral region in 2 cases. After temporoparietooccipital disconnection in 14 patients, 13 cases were seizure-free; only one case still had seizures, but the frequency dropped by more than 50%. CONCLUSIONS: Temporoparietooccipital disconnection is a safe and effective surgical procedure for children with intractable epilepsy due to posterior quadrantic cortical dysplasia.

Fragile X syndrome screening in Chinese children with unknown intellectual developmental disorder.

BACKGROUND: Fragile X syndrome is the most common genetic disorder of intellectual developmental disorder/mental retardation (IDD/MR). The prevalence of FXS in a Chinese IDD children seeking diagnosis/treatment in mainland China is unknown. METHODS: Patients with unknown moderate to severe IDD were recruited from two children's hospitals. Informed consent was obtained from the children's parents. The size of the CGG repeat was identified using a commercial TP-PCR assay. The influence of AGG interruptions on the CGG expansion during maternal transmission was analyzed in 24 mother-son pairs (10 pairs with 1 AGG and 14 pairs with 2 AGGs). RESULTS: 553 unrelated patients between six months and eighteen years of age were recruited. Specimens from 540 patients (male:female = 5.2:1) produced high-quality TP-PCR data, resulting in the determination of the FMR1 CGG repeat number for each. The most common repeat numbers were 29 and 30, and the most frequent interruption pattern was 2 or 3 AGGs. Five full mutations were identified (1 familial and 4 sporadic IDD patients), and size mosaicism was apparent in 4 of these FXS patients (4/5 = 80%). The overall yield of FXS in the IDD cohort was 0.93% (5/540). Neither the mean size of CGG expansion (0.20 vs. 0.79, p > 0.05) nor the frequency of CGG expansion (2/10 vs. 9/14, p > 0.05) was significantly different between the 1 and 2 AGG groups following maternal transmission. CONCLUSIONS: The FMR1 TP-PCR assay generates reliable and sensitive results across a large number of patient specimens, and is suitable for clinical genetic diagnosis. Using this assay, the prevalence of FXS was 0.93% in Chinese children with unknown IDD.

[Clinical presentations of pediatric anti-N-methyl-D-aspartate receptor encephalitis].

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is one of the most common autoimmune encephalitis in children with characterized clinical features. Here we review clinical presentations of typical and atypical anti-NMDAR encephalitis and characteristics of clinical presentations of pediatric anti-NMDAR encephalitis.

Long-term seizure and developmental outcomes of epilepsy surgery in children under 3 years old: A single-center study of 113 patients.

AIMS: To investigate the clinical characteristics, surgical strategy, developmental and seizure outcomes, and predictors of surgical outcome in children with drug-resistant epilepsy (DRE) under 3 years old. METHODS: One hundred thirteen consecutive children younger than 3 years of age with DRE underwent curative surgical treatment after multidisciplinary preoperative evaluation using the strategy developed in the pediatric epilepsy center of Peking University First Hospital (PKFHPEC) between 2014 and 2018. These patients were selected for retrospective study. The relevant clinical data were collected and analyzed. The surgical prognoses were classified using the Engel classification, and the developmental assessment results were collected. Statistical analysis of the clinical data was performed to analyze the predictors of seizure outcomes and their correlation with developmental outcomes. RESULTS: All the patients were followed up for more than 3 years, and 98 (86.7%) patients had no seizure recurrence. One year after surgery, the seizure-free rate was 86.7%, which was as high as that at the last follow-up. Cortical dysplasia was the most frequent etiology of DRE in this cohort, accounting for 77.0%. According to the Engel classification, acute postoperative seizure (APOS; p < 0.001) was a predictor of seizure recurrence. No deaths occurred. No unpredicted long-term severe complications occurred except for one ventricular peritoneal shunt. The patients' neurodevelopmental statuses were improved after successful surgery, while the scores of the pre- and postoperative developmental assessments were closely correlated. CONCLUSIONS: For children who are younger than 3 years old and have DRE and structural abnormalities, early curative treatment can lead to long-term good seizure outcomes and a low complication rate. The development of appropriate strategies for both presurgical evaluation and resection is crucial for the success of surgery.

Clinical features of unilateral multilobar and hemispheric polymicrogyria (PMG)-related epilepsy and seizure outcome with different treatment options.

OBJECTIVE: To provide evidence for choosing surgical or nonsurgical treatment for epilepsy in patients with unilateral multilobar and hemispheric polymicrogyria (PMG). METHODS: We searched published studies until September 2022 related to unilateral multilobar and hemispheric PMG and included patients who were followed up at the Pediatric Epilepsy Centre of Peking University First Hospital in the past 10 years. We summarized the clinical characteristics and compared the long-term outcomes after surgical or nonsurgical (anti-seizure medications, ASMs) treatment. RESULTS: A total of 70 patients (49 surgical, 21 non-surgical) with unilateral multilobar and hemispheric PMG were included. The median age at epilepsy onset was 2.5 years (1.0-4.1). The most common seizure types were focal and atypical absence seizures. In the whole cohort, 87.3% had hemiparesis and 67.1% had electrical status epilepticus during slow sleep (ESES). There were significant differences in age at epilepsy onset, extent of lesion, and EEG interictal discharges between the two groups. At the last follow-up (median 14.1 years), the rates of seizure-freedom (81.6% vs. 57.1%, p = 0.032) and ASM discontinuation (44.4% vs. 6.3%, p = 0.006) were higher in the surgical group than in the nonsurgical group. Patients in the surgical group had a higher rate of seizure-freedom with complete resection/disconnection than with subtotal resection (87.5% vs. 55.6%, p = 0.078), but with no statistically significant difference. In the nonsurgical group, more extensive lesions were associated with worse seizure outcomes. Cognition improved postoperatively in 90% of surgical patients. SIGNIFICANCE: In patients with unilateral multilobar and hemispheric PMG, the age of seizure onset, the extent of the lesion and EEG features can help determine whether surgery should be performed early. Additionally, surgery could be more favorable for achieving seizure freedom and cognitive improvement sooner. PLAIN LANGUAGE SUMMARY: We aim to summarize clinical characteristics and compare the long-term outcomes after surgical and nonsurgical (ASM) treatment to provide a basis for treatment decisions for patients with unilateral multilobar and hemispheric polymicrogyria (PMG)-related epilepsy. We found that patients with unilateral hemispheric and multilobar PMG had significantly higher rates of seizure freedom and ASM discontinuation with surgical treatment than with nonsurgical treatment. In the surgical group, seizure outcomes were better in patients treated with complete resection/disconnection than in those treated with subtotal resection, but the difference was not statistically significant.

[Peripheral nervous impairment in a patient with methylmalonic aciduria combined with hyperhomocysteinemia].

Methylmalonic aciduria combined homocysteinemia can cause multisystemic damages, mainly involving central nervous system, while the peripheral nerves are rarely impaired. A 10-year-old boy complained of weakness of both lower extremities for 1 month. His past history showed mildly delay of intelligence as well as motor development. He had proteinuria when he was 3 years old and was diagnosed as epilepsy, which was controlled by sodium valproate when he was 8 years 6 months old. His physical examination showed attenuated bilateral knee jerk reflex, while the bilateral achilles tendon reflex was absent; the examination of sensation was normal and the bilateral Babinski sign was positive. The electromyography indicated injury of peripheral nerves. The elevated levels of urine methylmalonic aciduria and plasma homocysteinemia were consistent with the diagnosis of methylmalonic aciduria combined homocysteinemia. The pathogenic gene was confirmed as MMACHC, on which two pathogenic mutations (c.365A>T and c.609G>A) were detected. cblC defect was confirmed. He was treated by vitamin B12, calcium folinate, L-carnitine and betaine supplementation, and significant improvement was observed after 6 months. According to this case, we suggest that urinary organic acid analysis and plasma homocysteine should be performed in patients with unknown peripheral neuropathy, especially combined with multisystemic damages.Early diagnosis and treatment are important to improve the prognosis.

[Epidemiological study on developmental delay of 18-month-old children from four districts/counties in Beijing].

OBJECTIVE: To investigate epidemiological characteristics of prevalence, impact factors and etiology on developmental delay of 18-month-old children from four districts/counties in Beijing. METHODS: An epidemiological study on developmental delay was designed to investigate all the 18-month-old children enrolled from Shunyi,Daxing,Miyun and Yanqing districts/counties in Beijing from May to September, 2011. Combining the tertiary network of child health with hospital clinical study was used. Child developmental questionnaires were completed by doctors in communities of the first network of child health. Gesell Developmental Schedules for children with Denver developmental screening test (DDST) screening positive results were assessed by doctors in districts/counties hospitals of the second network of child health. The children diagnosed as developmental delay were transferred to the tertiary hospitals of the third network of child health for further etiological diagnosis, follow-up and developmental evaluation. The case-control study compared between children with/without developmental delay were performed in accordance with the 1:4 ratios by gender and residence community matched. SPSS 16.0 was adopted for data analysis of the case-control study. RESULTS: A total of 3 182 children were screened among the 4 037 children fitting the criteria,and the coverage rate was 78.8% (3 182/4 037). Of the 3 182 screened children, 22 children were diagnosed as developmental delay. The prevalence rate was 6.91 ‰ (22/3 182). Out of the 22 children with developmental delay, 15 were boys and 7 were girls. The sex ratio was 2.1:1. The prevalence rates of the children with developmental delay in Shunyi, Daxing, Miyun and Yanqing were 3.45 ‰ (4/1 160), 4.50 ‰(5/1 111), 15.87 ‰(7/441) and 12.77 ‰ (6/479), respectively. The results from one-way ANOVA analysis showed the main risk factors in children with developmental delay included low-income families, mothers' low educational level, small size for gestational age infant, multiple fetuses, serious diseases after birth, congenital malformations and physical retardation (P<0.05). CONCLUSION: The screening coverage rate of this study is 78.8%. The prevalence rate of children with developmental delay is 6.91 ‰, which is significantly different in sex ratio and districts of the subjects. The etiology of developmental delay might be associated with social-economic and biological factors.

Brain functional connectivity-based prediction of vagus nerve stimulation efficacy in pediatric pharmacoresistant epilepsy.

OBJECTIVE: Although vagus nerve stimulation (VNS) is a common and widely used therapy for pharmacoresistant epilepsy, the reported efficacy of VNS in pediatric patients varies, so it is unclear which children will respond to VNS therapy. This study aimed to identify functional brain network features associated with VNS action to distinguish VNS responders from nonresponders using scalp electroencephalogram (EEG) data. METHODS: Twenty-three children were included in this study, 16 in the discovery cohort and 7 in the test cohort. Using partial correlation value as a measure of whole-brain functional connectivity, we identified the differential edges between responders and nonresponders. Results derived from this were used as input to generate a support vector machine-learning classifier to predict VNS outcomes. RESULTS: The postcentral gyrus in the left and right parietal lobe regions was identified as the most significant differential brain region between VNS responders and nonresponders (p < 0.001). The resultant classifier demonstrated a mean AUC value of 0.88, a mean sensitivity rate of 91.4%, and a mean specificity rate of 84.3% on fivefold cross-validation in the discovery cohort. In the testing cohort, our study demonstrated an AUC value of 0.91, a sensitivity rate of 86.6%, and a specificity rate of 79.3%. Furthermore, for prediction accuracy, our model can achieve 81.4% accuracy at the epoch level and 100% accuracy at the patient level. SIGNIFICANCE: This study provides the first treatment response prediction model for VNS using scalp EEG data with ictal recordings and offers new insights into its mechanism of action. Our results suggest that brain functional connectivity features can help predict therapeutic response to VNS therapy. With further validation, our model could facilitate the selection of targeted pediatric patients and help avoid risky and costly procedures for patients who are unlikely to benefit from VNS therapy.

Novel STAMBP mutations in a Chinese girl with rare symptoms of microcephaly-capillary malformation syndrome and Mowat-Wilson syndrome.

Microcephaly-capillary malformation syndrome (MIC-CAP) and Mowat-Wilson syndrome (MWS) are both rare hereditary diseases with several overlapping symptoms. We here report a Chinese patient simultaneously affected by MIC-CAP and MWS, presenting with moderate anaemia because of repeated, unilateral refractory epistaxis. The girl was initially diagnosed with MWS after discovery of a pathogenic nonsense mutation in ZEB2. Starting from the age of 3 years old, the child experienced repeated epistaxis on the right side without obvious incentive or trauma. The bleeding was quite difficult to stop and her hemoglobin dropped from 124 g/L to 64 g/L in three months. Both coagulation disorders and allergic rhinitis were excluded by extensive workup and experimental therapeutics. Retrospective genetic analysis revealed that she carried two novel compound heterozygous mutations in STAMBP (c.610T > C: p.Ser204Pro and c.945C > G: p.Asn315Lys). This case report demonstrates a rare presentation of MIC-CAP in the pediatric population and enriches the variant spectrum of STAMBP.

Identification of GJC2 gene mutations in Chinese patients with Pelizaeus-Merzbacher-like disease.

BACKGROUND: Clinical and genetic features were analyzed in five pedigrees with Pelizaeus-Merzbacher-like disease (PMLD) to provide bases for genetic counseling and prenatal diagnosis. CONCLUSIONS: Six patients from five pedigrees were diagnosed with PMLD based on their clinical data. Six GJC2 novel mutations were found in this study, expanding the spectrum of GJC2 mutations. This is the second group of GJC2 mutations reported from six Chinese patients with PMLD. METHODS: Clinical data including medical history, physical signs, and auxiliary examinations were collected from six patients and their family numbers in five pedigrees with PMLD. Polymerase chain reaction and sequence analysis were used to amplify GJC2 and PLP1 alterations, while multiplex ligation-dependent probe amplification (MLPA) was performed to detect PLP1 dosage changes. The gene mutations were diagnosed for further analysis of the genetic features. RESULTS: A total of seven GJC2 mutations were identified in these patients, including two novel missense mutations (c.217C>T, p.Pro73Ser; c.1199C>A, p.Ala400Glu), one nonsense mutation (c.735C>A, p.Cys245X), three novel frameshift mutations (c.579delC, p.Gly193fsX17 and c.1296_1297insG, p.Gly433fsX59; c.689delG, p.Gly230AlafsX241), and one known missense mutation (c.814T>G, p.Tyr272Asp). Compound heterozygotes were found for P1-3, while homozygotes were found for P4-6 that were inherited from their parents with normal phenotypes except for P5 and P6, respectively. The c.814T>G (p.Tyr272Asp) mutation in P5 was de novo. A c.1199C>A (p.Ala400Glu) homozygous mutation in GJC2 was identified in P6. A heterozygous variation was found in his father and the wild type was seen in his mother.

Efficient and generalizable cross-patient epileptic seizure detection through a spiking neural network.

Introduction: Epilepsy is a global chronic disease that brings pain and inconvenience to patients, and an electroencephalogram (EEG) is the main analytical tool. For clinical aid that can be applied to any patient, an automatic cross-patient epilepsy seizure detection algorithm is of great significance. Spiking neural networks (SNNs) are modeled on biological neurons and are energy-efficient on neuromorphic hardware, which can be expected to better handle brain signals and benefit real-world, low-power applications. However, automatic epilepsy seizure detection rarely considers SNNs. Methods: In this article, we have explored SNNs for cross-patient seizure detection and discovered that SNNs can achieve comparable state-of-the-art performance or a performance that is even better than artificial neural networks (ANNs). We propose an EEG-based spiking neural network (EESNN) with a recurrent spiking convolution structure, which may better take advantage of temporal and biological characteristics in EEG signals. Results: We extensively evaluate the performance of different SNN structures, training methods, and time settings, which builds a solid basis for understanding and evaluation of SNNs in seizure detection. Moreover, we show that our EESNN model can achieve energy reduction by several orders of magnitude compared with ANNs according to the theoretical estimation. Discussion: These results show the potential for building high-performance, low-power neuromorphic systems for seizure detection and also broaden real-world application scenarios of SNNs.

Safety and efficacy of rapid withdrawal of antiseizure medications during long-term video-electroencephalogram monitoring in children with drug-resistant epilepsy: A retrospective study.

OBJECTIVE: Performing long-term video-electroencephalographic monitoring (LTVEM) to obtain the ictal electroencephalogram (EEG) is important for presurgical evaluation. This study aimed at investigating the safety and efficacy of our protocol developed at Peking University First Hospital (PUFH) for rapid withdrawal of antiseizure medications (ASMs) during LTVEM to induce seizures in children with drug-resistant epilepsy (DRE) exhibiting nondaily seizures. METHODS: Children with DRE who followed the PUFH protocol for rapid withdrawal of ASMs during LTVEM between 2018 and 2021 were enrolled. The occurrence of seizures, number of ASMs withdrawn, seizure onset time after ASM tapering initiation, changes in interictal epileptiform discharge (IED), and adverse events were evaluated during LTVEM. RESULTS: Among 80 children evaluated in this study, seizures were induced successfully in 72 (90%) children. Furthermore, no change in IED sites was observed in these 72 children following the initiation of ASM tapering while 2 children exhibited secondary bilateral tonic-clonic seizures. The median time from ASM tapering initiation to the onset of the first seizure was found to be 3 days (2-4), while the median number of ASMs withdrawn was 2 (1-2). Finally, 66 children (91.7%) had habitual seizures while 6 children had nonhabitual seizure semiology. SIGNIFICANCE: The PUFH protocol can be used for the rapid withdrawal of ASMs during LTVEM in children with DRE. Using this protocol, ictal EEG patterns can be obtained in a relatively short time for most patients with fewer adverse effects during LTVEM, which may provide meaningful electro-clinical information for presurgical evaluation.

Pediatric epilepsy surgery in patients with Lennox-Gastaut syndrome after viral encephalitis.

Objective: To analyse the surgical outcomes of pediatric patients with Lennox-Gastaut syndrome (LGS) secondary to viral encephalitis. Methods: We retrospectively analyzed the data of four patients with LGS secondary to viral encephalitis who underwent surgery at the pediatric epilepsy center of Peking University First Hospital from January 2014 to December 2019. Preoperative evaluations included a detailed history, long-term video electroencephalography (VEEG), brain magnetic resonance imaging (MRI), positron emission tomography (PET) and a neuropsychological test. All patients were followed up at 1, 3, and 6 months and then yearly. The surgical outcome was evaluated according to the Engel classification. Results: Among the four children, the surgeries were right temporo-parieto-occipital disconnection (case 1), corpus callosotomy (case 2), left temporo-parieto-occipital disconnection (case 3), and left temporal lobectomy (case 4). The pathology was gliosis secondary to viral encephalitis. The median follow-up time was 4 years (3-5 years). At the last follow-up, one case had Engel I, two cases had Engel III, and one case had Engel IV. Conclusions: Preliminary observations shows that surgical treatment may be challenging for patients with LGS secondary to viral encephalitis. However, suitable surgical candidacy and approaches have a significant impact on the prognosis of the patients.

Identification of gene mutations in six Chinese patients with maple syrup urine disease.

Background: Maple syrup urine disease (MSUD) is a rare autosomal recessive amino acid metabolic disease. This study is to identify the pathogenic genetic factors of six cases of MUSD and evaluates the application value of high-throughput sequencing technology in the early diagnosis of MUSD. Methods: Clinical examination was carried out for patients and used blood tandem mass spectrometry (MS/MS), urine gas chromatography-mass spectrometry (GC/MS), and the application of high-throughput sequencing technology for detection. Validate candidate mutations by polymerase chain reaction (PCR)-Sanger sequencing technology. Bioinformatics software analyzed the variants' pathogenicity. Using Swiss PDB Viewer software to predict the effect of mutation on the structure of BCKDHA and BCKDHB proteins. Result: A total of six MSUD patients were diagnosed, including four males and two females. Nine variants were found in three genes of six MSUD families by high-throughput sequencing, including four missense mutations: c.659C>T(p.A220V), c.818C>T(p.T273I), c.1134C>G(p.D378E), and c.1006G>A(p.G336S); two non-sense mutations: c.1291C>T(p.R431*) and c.331C>T(p.R111*); three deletion mutations: c.550delT (p.S184Pfs*46), c.718delC (p.P240Lfs*14), and c.795delG (p.N266Tfs*64). Sanger sequencing's results were consistent with the high-throughput sequencing. The bioinformatics software revealed that the mutations were harmful, and the prediction results of Swiss PDB Viewer suggest that variation affects protein conformation. Conclusion: This study identified nine pathogenic variants in the BCKDHA, BCKDHB, and DBT genes in six MSUD families, including two novel pathogenic variants in the BCKDHB gene, which enriched the genetic mutational spectrum of the disease. High-throughput sequencing is essential for the MSUD's differential diagnosis, early treatment, and prenatal diagnosis.

Clinical characteristics and surgical outcomes in children with mild malformation of cortical development and oligodendroglial hyperplasia in epilepsy.

OBJECTIVE: Mild malformation of cortical development with oligodendroglial hyperplasia in epilepsy (MOGHE) is a new and rare histopathological entity of cortical developmental malformations. The clinical characteristics of MOGHE remain challenging. METHODS: Children with histologically confirmed MOGHE were retrospectively studied. The clinical findings, electroclinical and imaging features, and postoperative outcomes were analyzed, and previously published studies were reviewed up to June 2022. RESULTS: Thirty-seven children were included in our cohort. Clinical characteristics included early onset in infancy (94.6% before 3 years), multiple seizure types, and moderate or severe delay. Epileptic spasm is the most common seizure type and initial manifestation. The lesions were mainly multilobar (59.5% multiple lobes and 8.1% hemispheres), and predominance in the frontal lobe was observed. The interictal EEG pattern was circumscribed or widespread. The prominent MRI characteristics were cortical thickening, cortical/subcortical hyperintense T2/FLAIR signal, and blurring at the GM and WM transition. Among the 21 children followed up for more than 1 year after surgery, 76.2% were seizure-free. Preoperative interictal circumscribed discharges and larger resections were significantly associated with a good postoperative outcome. The clinical features of 113 patients in the reviewed studies were similar to those we reported, but the lesions were mainly unilobar (73.5%) and Engel I was achieved in only 54.2% after surgery. SIGNIFICANCE: Distinct clinical characteristics in MOGHE, especially age at onset, epileptic spasm, and age-related MRI characteristics, can help in early diagnosis. Preoperative interictal discharge and surgical strategy may be predictors of postoperative outcomes.

NIPA2 located in 15q11.2 is mutated in patients with childhood absence epilepsy.

While pathogenic copy number variations (CNVs) in 15q11.2 were recently identified in Caucasian patients with idiopathic generalized epilepsies (IGEs), the epilepsy-associated gene(s) in this region is/are still unknown. Our study investigated whether the CNVs in 15q11.2 are associated with childhood absence epilepsy (CAE) in Chinese patients and whether the selective magnesium transporter NIPA2 gene affected by 15q11.2 microdeletions is a susceptive gene for CAE. We assessed IGE-related CNVs by Affymetrix SNP 5.0 microarrays in 198 patients with CAE and 198 controls from northern China, and verified the identified CNVs by high-density oligonucleotide-based CGH microarrays. The coding region and exon-intron boundaries of NIPA2 were sequenced in all 380 patients with CAE and 400 controls. 15q11.2 microdeletions were detected in 3 of 198 (1.5%) patients and in no controls. Furthermore, we identified point mutations or indel in a heterozygous state of the NIPA2 gene in 3 out of 380 patients, whereas they were absent in 700 controls (P = 0.043). These mutations included two novel missense mutations (c.532A>T, p.I178F; c.731A>G, p.N244S) and one small novel insertion (c.1002_1003insGAT, p.N334_335EinsD). No NIPA2 mutation was found in 400 normal controls. We first identified that NIPA2, encoding a selective magnesium transporter, is a susceptible gene of CAE, and 15q11.2 microdeletions are important pathogenic CNVs for CAE with higher frequency in Chinese populations than that previously reported in Caucasians. The haploinsufficiency of NIPA2 may be a mechanism underlying the neurological phenotypes of 15q11.2 microdeletions.