Long-term efficacy and safety of adjunctive perampanel in pediatric patients aged 4-19 years with epilepsy: a real-world study.

This study determined the 24-month outcomes of perampanel treatment in children and adolescents with epilepsy. The percentage of ≥ 50% responders was 47.3% (139/294) at 12 months and 49.0% (144/294) at 24 months. A 100% reduction in seizures for more than 12 months was observed in 12.2% (36/294). Discontinuation occurred in 39.8% (117/294). The most common reason for discontinuation was adverse events (29.1%, 34/117). Baseline seizure frequency was higher in children aged < 12 years than in patients aged ≥ 12 years; however, the percentage of seizure reduction and ≥ 50% responders did not significantly differ between the two groups. The rate of early discontinuation was higher (p < 0.001) and the duration of perampanel treatment was shorter in children aged < 12 years (p = 0.001). Most children aged < 12 years discontinued PER due to inadequate effectiveness, while adverse event was the most common reason in patients aged ≥ 12 years (p = 0.045). Only slow titration was significantly associated with ≥ 50% of responders. In conclusion, this study showed that perampanel can be utilized effectively and safely for a prolonged period in pediatric patients aged 4 to < 12 years, as well as in patients aged 12 years and older.

Neuroprotective effect of both synbiotics and ketogenic diet in a pentylenetetrazol-induced acute seizure murine model.

OBJECTIVE: We aimed to maximize the efficacy of both ketogenic diet (KD) and other treatments to protect brain from acute seizure. METHODS: L. fermentum MSK 408 strain, galactooligosaccharide (GOS), and L. fermentum MSK 408 with GOS were administered with two different diets for 8 weeks. To reveal the relationships among gut microbiota, fecal short-chain fatty acids (SCFAs) and brain related action against pentylenetetrazole (PTZ)-induced kindling, qPCR, NGS, and GC-MS analyses were used. RESULTS: KD administration significantly reduced PTZ-induced seizure through reducing cell damage in the specific part of the brain; this effect was not interrupted by co-administration of synbiotics. Additionally, the synbiotic-treated normal diet (ND) group showed reduced seizure-related scores. SCFA concentrations of both KDs and ND with synbiotics (NDS) were dramatically reduced compared to those with NDs. Interestingly, NDS group showed independently different SCFAs ratios compared to both ND and KD group, possibly related to a reduction in seizure symptoms compared with that by KD groups. The gut microbiota modulation by KD suggested that the gut microbiota aids the host in generating energy, thus increase the usage of SCFAs such as butyrate and acetate. SIGNIFICANCE: The results suggest that KD could reduce PTZ-induced seizures through modulating various factors such as the neuroendocrine system, brain protection, gut microbiota, fecal SCFAs, and gene expression in the gut and brain. Additionally, synbiotic treatment with KD could be a better method to reduce the side effects of KD without interrupting its anti-seizure effect. However, ND with synbiotics seizure reducing effect requires further analysis.

Long-term results of vagus nerve stimulation in children with Dravet syndrome: Time-dependent, delayed antiepileptic effect.

OBJECTIVE: This study aimed to assess the long-term outcomes of vagus nerve stimulation (VNS) in children with pharmaco-resistant Dravet syndrome (DS). METHODS: We enrolled 22 patients with pharmaco-resistant DS who underwent VNS implantation at Severance Children's Hospital from March 2005 to October 2020. Efficacy and tolerability were assessed at 3, 6, 12, 18, 24, 30, and 36 months after VNS implantation. Efficacy was measured as the percentage reduction in seizure frequency at each follow-up compared with the baseline (pre-implantation) values. RESULTS: Median patient age at VNS implantation was 10.0 years (interquartile range 7.7-13.3). The median follow-up period was 4.3 years (interquartile range 3.0-6.5) after VNS implantation. All cases were followed up for ≥2 years after VNS implantation. Three (13.6 %) patients maintained seizure freedom for ≥1 year. Among them, one achieved seizure freedom after 30 months of VNS. More than 50 % reduction in seizure frequency was observed in 36.4 % (8/22), 54.5 % (12/22), and 63.2 % (12/19) of the patients at 12, 24, and 36 months, respectively. The median percent reduction in seizure frequency was 18.8 %, 50.6 %, and 60.0 % at 12, 24, and 36 months, respectively. Compared with the baseline value, the seizure frequency was significantly lower at 24, 30, and 36 months, as well as at the longest follow-up period (p < 0.05, Wilcoxon signed-rank test). The symptom that was mostly associated with adverse events was hoarseness (4/22, 18.2 %); however, they had temporary or minimal effects on activities of daily living. CONCLUSIONS: Our findings demonstrate that VNS therapy allows long-term, progressive, and time-dependent improvement in seizure control for pharmaco-resistant DS. Clinicians should be aware of the delayed VNS efficacy over the years and should encourage long-term VNS maintenance by patients.

Long-term outcomes of ketogenic diet in patients with tuberous sclerosis complex-derived epilepsy.

OBJECTIVE: For epilepsy with tuberous sclerosis complex (TSC), ketogenic diet (KD) therapy has been consistently reported to be more beneficial than the average KD therapy response. Herein, we aimed to investigate the long-term outcomes of a KD on patients with TSC and intractable epilepsy. METHODS: This study included 31 patients with intractable epilepsy and TSC who were treated with the KD, and an intention-to-treat analysis was performed. RESULTS: Overall, 21 of the 31 patients (67.7%) had >50% reduction in seizures at 3 months after initiating the KD. Thirteen of the 31 patients (41.9%) were seizure-free for at least 3 months, but 10 of these 13 patients (76.9%) experienced seizure recurrence during the 24-month follow-up period. Finally, at 24 months of the KD observational period, there was >50% response in 10 of the 31 patients (32.3%), including seizure-free patients (6 of 31 patients, 19.4%). Most of the patients (12 of 13, 92.3%) who experienced seizure freedom had >50% reduction in seizures within 1 month after initiating the KD, and this result was the only factor associated with seizure freedom in the current study. CONCLUSION: The KD appeared to be an effective therapeutic modality for intractable pediatric epilepsy in TSC, but it did not exhibit guaranteed efficacy over a long-term period.

Vigabatrin and high-dose prednisolone therapy for patients with West syndrome.

OBJECTIVE: Hormonal therapy and vigabatrin are now accepted as the first-line or standard therapies for West syndrome (WS). However, the superiority of these drugs in terms of monotherapy or combination therapy is still in question. In this study, we designed a treatment protocol for WS and prospectively assessed the efficacy of these therapies in controlling spasms, stabilizing electroencephalography (EEG), and allowing for developmental catch-up. METHODS: In patients diagnosed with WS, vigabatrin was first administered alone for 2 weeks, and then prednisolone was administered in combination with vigabatrin if patients did not respond to vigabatrin. The detailed drug administration protocol was as follows: vigabatrin 50 mg/kg/day for 1 day, followed by vigabatrin 100 mg/kg/day for 3 days, vigabatrin 150 mg/kg/day if spasms were still present or the burden of amplitudes and epileptiform discharges (BASED) score on EEG was ≥3 on day 5; 40 mg/day of prednisolone was added if spasms were still present or the BASED score was ≥3 on day 14. The prednisolone dose was increased to 60 mg/day if spasms were still present or the BASED score was ≥3 on day 21. RESULTS: Sixty-six patients newly diagnosed with WS (median seizure onset age: 5.7 [IQR, 4.1-7.1] months, median age at diagnosis: 6.6 [IQR, 5.4-8.1] months, n = 40 [60.6%] boys) were subjected to the vigabatrin and prednisolone therapy protocol. Of the 66 patients, 22 (33.3%) patients showed resolution of spasms and a BASED score of ≤2 after vigabatrin alone, and 26 (39.4%) patients showed resolution of spasms and a BASED score of ≤2 after a combination of vigabatrin and prednisolone, for a total of 48 (72.7%) patients who were responsive to the protocol without relapse for at least 7 months after WS diagnosis. The mental and psychomotor age quotients were higher at the time of diagnosis and remained significantly higher 6 months after the diagnosis in responsive patients (p <  0.001). No serious adverse reactions leading to discontinuation or reduction of drug doses were observed. CONCLUSION: Using a treatment protocol involving vigabatrin and prednisolone for WS, 72.7% of patients showed resolution of spasms and a BASED score of ≤2. This study also found that this drug administration protocol was safe. However, further studies are warranted as this study describes results from observational study with limited sample size.

Adverse Events During Perampanel Adjunctive Therapy in Intractable Epilepsy.

BACKGROUND AND PURPOSE: Perampanel is the first α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA)-receptor antagonist developed to treat epilepsy. The effects of either rapid or slow dose titration on adverse events remain to be elucidated. METHODS: Eighty-five patients received perampanel between March 2016 and August 2016. Patients were divided into two groups according to their dosing schedule: rapid dose titration (2-mg increments at intervals of 1 to 2 weeks) and slow dose titration (2-mg increments at intervals of at least 3 weeks). Seizure frequency and adverse events were analyzed over 3 months. RESULTS: Adverse events were reported by 47 (58%) of the 81 patients analyzed, with 12 (15%) patients discontinuing perampanel due to adverse events. Common adverse events included dizziness (n=30, 37%), aggressive mood and behavior (n=19, 24%), gait disturbance (n=16, 20%), and sleep problems (n=10, 12.4%). The overall adverse events were similar in the slow-titration group (38 of 61 patients) and the rapid-titration group (8 of 20 patients, p=0.081). However, none of the 20 patients in the slow-titration group experienced gait disturbance, compared with 16 of the 61 patients in the rapid-titration group (p=0.009), while appetite change was experienced by 4 patients in the slow-titration group but only 1 in the rapid-titration group (p=0.003). No relationship was noted between adverse events and the maximum dose of perampanel (p=0.116). Sex differences were observed, with the response to perampanel being better and the rate of adverse events being higher in females (p=0.015 and p=0.046, respectively). CONCLUSIONS: Slow titration of perampanel may reduce perampanel-related adverse events.

Efficient strategy for the molecular diagnosis of intractable early-onset epilepsy using targeted gene sequencing.

BACKGROUND: We intended to evaluate diagnostic utility of a targeted gene sequencing by using next generation sequencing (NGS) panel in patients with intractable early-onset epilepsy (EOE) and find the efficient analytical step for increasing the diagnosis rate. METHODS: We assessed 74 patients with EOE whose seizures started before 3 years of age using a customized NGS panel that included 172 genes. Single nucleotide variants (SNVs) and exonic and chromosomal copy number variations (CNVs) were intensively examined with our customized pipeline and crosschecked with commercial or pre-built software. Variants were filtered and prioritized by in-depth clinical review, and finally classified according to the American College of Medical Genetics and Genomics guidelines. Each case was further discussed in a monthly consensus meeting that included the participation of all laboratory personnel, bioinformaticians, geneticists, and clinicians. RESULTS: The NGS panel identified 28 patients (37.8%) with genetic abnormalities; 25 patients had pathogenic or likely pathogenic SNVs in 17 genes including SXTBP1 (n = 3), CDKL5 (n = 2), KCNQ2 (n = 2), SCN1A (n = 2), SYNGAP1 (n = 2), GNAO1 (n = 2), KCNT1 (n = 2), BRAT1, WWOX, ZEB2, CHD2, PRICKLE2, COL4A1, DNM1, SCN8A, MECP2, SLC9A6 (n = 1). The other 3 patients had pathogenic CNVs (2 duplications and 1 deletion) with varying sizes (from 2.5 Mb to 12 Mb). The overall diagnostic yield was 37.8% after following our step-by-step approach for clinical consensus. CONCLUSIONS: NGS is a useful diagnostic tool with great utility for patients with EOE. Diagnostic yields can be maximized with a standardized and team-based approach.

Targeted gene panel and genotype-phenotype correlation in children with developmental and epileptic encephalopathy.

OBJECTIVE: We performed targeted gene-panel sequencing for children with developmental and epileptic encephalopathy (DEE) and evaluated the clinical implications of genotype-phenotype correlations. METHODS: We assessed 278 children with DEE using a customized gene panel that included 172 genes, and extensively reviewed their clinical characteristics, including therapeutic efficacy, according to genotype. RESULTS: In 103 (37.1%) of the 278 patients with DEE, 35 different disease-causing monogenic mutations were identified. The diagnostic yield was higher among patients who were younger at seizure onset, especially those whose seizures started during the neonatal period, and in patients with drug-resistant epilepsy. According to epilepsy syndromes, the diagnostic yield was the highest among patients with West syndrome (WS) with a history of neonatal seizures and mutations in KCNQ2 and STXBP1 were most frequently identified. On the basis of genotypes, we evaluated the clinical progression and seizure outcomes with specific therapeutic regimens; these were similar to those reported previously. In particular, sodium channel blockers were effective in patients with mutations in KCNQ2 and SCN2A in infancy, as well as SCN8A, and interestingly, the ketogenic diet also showed diverse efficacy for patients with SCN1A, CDKL5, KCNQ2, STXBP1, and SCN2A mutations. Unfortunately, quinidine was not effective in 2 patients with migrating focal epilepsy in infancy related to KCNT1 mutations. CONCLUSION: Targeted gene-panel sequencing is a useful diagnostic tool for DEE in children, and genotype-phenotype correlations are helpful in anticipating the clinical progression and treatment efficacy among these patients.

Electroencephalography Network Effects of Corpus Callosotomy in Patients with Lennox-Gastaut Syndrome.

OBJECTIVES: This study aimed to investigate the functional network effects of corpus callosotomy (CC), a well-recognized palliative surgical therapy for patients with Lennox-Gastaut syndrome (LGS). Specifically, we sought to gain insight into the effects of CC on LGS remission, based on brain networks in LGS by calculating network metrics and evaluating by network measures before and after surgery. METHODS: Electroencephalographic recordings made during preoperative and 3-month postoperative states in 14 patients with LGS who had undergone successful CC were retrospectively analyzed. First, undirected correlation matrices were constituted for the mathematical expression of functional networks. Then, we plotted these networks to analyze the effects of CC on connectivity. In addition, conventional local and global network measures were applied to evaluate differences in network topology between preoperative and postoperative states. RESULTS: In the preoperative state, hubs were mainly distributed around the paramedian regions. After CC, the hubs moved from the paramedian regions to the dual-hemisphere and even the lateral regions. Thus, the general connectivity state became more homogeneous, which was verified by network plots and statistical analysis of local measures. The results of global network measures indicated a decreased clustering coefficient in the delta band, decreased characteristic path length in both the delta and gamma bands, and increased global efficiency in the gamma band. CONCLUSION: Our results showed a consistent variation in the global brain network that converted to a small-world topology with an optimal balance of functional integration and segregation of the network. Such changes were positively correlated with satisfactory surgery results, which could be interpreted as being indicative of LGS recovery process after CC. For patients with refractory LGS along with no focal epileptogenic zone findings, which were not suitable for the resective surgical therapy, our results verified that CC could work as an effective surgical treatment option.