[Analysis of the efficacy and influencing factors of sodium channel blockers in the treatment of focal epilepsy in infants under 6 months of age].

Objective: To analyze the efficacy and safety of the sodium channel blockers (SCB) antiseizure medication in the treatment of focal epilepsy in infants under 6 months of age. Methods: This was a case series study. Infants with focal epilepsy with onset within 6 months of age and treated with SCB attending the Department of Neurology of Beijing Children's Hospital from June 2016 to April 2022 were collected. The clinical data, auxiliary examinations, SCB application, efficacy, adverse reactions, and prognosis were analyzed retrospectively. Patients were grouped according to type of seizure and epileptic syndrome, age of onset and etiology. Chi square test and Fisher exact test were used to analyze the differences between groups statistically. Results: A total of 118 infants were enrolled, 65 males and 53 females, with an age of epilepsy onset of 56 (4, 114) days. Developmental and epileptic encephalopathy was diagnosed in 60 infants, 39 had self-limited neonatal and (or) infantile epilepsy, and 19 had non-syndromic focal epilepsy. Application of SCB: 106 used oxcarbazepine, 2 used lacosamide, 9 switched from oxcarbazepine to lacosamide or a combination of 2 SCB, and 1 used oxcarbazepine, lacosamide, and lamotrigine successively; oxcarbazepine was the first choice in 46 cases. The age at which SCB was applied was 103 (53, 144) days. The children were followed up for 6 months to 6 years. SCB was effective in 89 cases (75.4%), including 70 cases (59.3%) who achieved seizure freedom. The seizure-free rate was higher in the focal epilepsy only group than in the group with other seizure types (64.4% (65/101) vs. 4/17, χ²=9.99, P<0.05). The responder and seizure-free rates were all higher in the group with the onset age of >3-6 months than the group >1-3 months (84.4% (38/45) vs. 62.5% (20/32), 73.3% (33/45) vs. 46.9% (15/32), χ²=4.85 and 5.58, both P<0.05). With the exception of variants in the PRRT2 gene, those with variants in sodium or potassium channels had higher responder and seizure-free rates than those with variants in other genes(86.2% (25/29) vs. 45.5% (10/22), 62.1% (18/29) vs. 22.7% (5/22), χ²=9.65 and 7.82,both P<0.05). The most common adverse event was transient hyponatremia, which happened in 66 cases (55.9%). There were 9 cases of rash, which subsided in 6 cases after discontinuing oxcarbazepine and switching to lacosamide, and 7 cases of electrocardiogram abnormalities, which improved after withdrawing oxcarbazepine and changing to lacosamide in 1 case. Conclusion: SCB are effective and tolerable in the treatment of focal epilepsy in infants under 6 months of age, with better efficacy in patients with genetic variants of the sodium or potassium channel, focal seizures only, and seizure onset >3-6 months of age.目的： 总结钠通道阻滞剂（SCB）类抗癫痫发作药物治疗6月龄以内婴儿尤其新生儿局灶性癫痫的效果和安全性。 方法： 病例系列研究，选择2016年6月至2022年4月就诊于北京儿童医院神经内科的6月龄以内发病并使用SCB治疗的118例局灶性癫痫患儿作为研究对象，收集并分析其临床资料、辅助检查、SCB应用情况、疗效、不良反应及预后等资料。根据癫痫发作类型及综合征、起病年龄、病因进行分组，采用χ²检验或Fisher确切概率法进行组间比较。 结果： 118例患儿中男65例、女53例，起病年龄为56（4，114）日龄。60例发育性癫痫性脑病，39例自限性新生儿和（或）婴儿癫痫，19例非综合征性局灶性癫痫。106例患儿使用奥卡西平，2例使用拉考沙胺，9例由奥卡西平转换为拉考沙胺或二者联用，1例使用奥卡西平、拉考沙胺及拉莫三嗪；46例以奥卡西平作为首选。应用SCB的年龄为103（53，144）日龄。随访6个月至6年，89例（75.4%）患儿SCB治疗有效，其中70例（59.3%）达到无发作。单纯局灶性发作组无发作率高于局灶合并其他发作类型组［64.4%（65/101）比4/17，χ²=9.99，P<0.05］；>3~6月龄起病组有效率及无发作率均高于>1~3月龄起病组［84.4%（38/45）比62.5%（20/32），73.3%（33/45）比46.9%（15/32），χ²=4.85、5.58，均P<0.05］；除外PRRT2基因变异组，钠或钾通道基因变异组的有效率和无发作率均高于其他基因变异组［86.2%（25/29）比45.5%（10/22），62.1%（18/29）比22.7%（5/22），χ²=9.65、7.82，均P<0.05］。最常见的不良事件是一过性低钠血症66例（55.9%）；有9例出现皮疹，6例停用奥卡西平改为拉考沙胺后皮疹消退；7例出现心电图异常，1例停用奥卡西平改为拉考沙胺后好转。 结论： SCB治疗6月龄以内婴儿的局灶性癫痫有效并且可耐受，对于钠或钾通道基因变异、仅局灶性发作及>3~6月龄起病的患儿疗效更好。.