Introduction

SCN8A-related epilepsy has various phenotypes. In particular, patients with developmental and epileptic encephalopathy (DEE) are resistant to antiepileptic drugs and may present with autonomic symptoms, such as marked bradycardia and apnea during seizures, and thus have an increased risk of sudden death. Herein, we report a case of very severe SCN8A-related epilepsy necessitating cardiac pacemaker implantation because of repetitive ictal asystole.

Case report

The patient was a 14-month-old girl. Tremor and generalized tonic seizure occurred after birth. During seizures, bradycardia and perioral cyanosis occurred, and then, after developing tachycardia and apnea, marked bradycardia and generalized cyanosis occurred, which sometimes resulted in ictal asystole requiring cardiopulmonary resuscitation. Her seizures were refractory to antiepileptic drugs. As the seizures requiring resuscitation did not decrease, cardiac pacemaker implantation was performed four months after birth. Exome sequencing revealed a heterozygous de novo variant in SCN8A (NM_014191.3:c.4934T>C,p.(Met1645Thr)). Even though phenytoin was effective, seizures with bradycardia remained approximately once a month, and pacemaker activity was observed.

Conclusions

This is, to our knowledge, the first reported case of SCN8A-related DEE in whom pacemaker implantation was performed. Pacemaker implantation should be considered as a treatment option for critical patients with SCN8A-related DEE as in the present case, because the incidence of sudden unexpected death in epilepsy is reported to be approximately 10% in patients with SCN8A-related DEE.

中文翻译：

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SCN8A 相关发育性和癫痫性脑病伴发作期心脏停搏，需要植入心脏起搏器

介绍

SCN8A相关癫痫具有多种表型。尤其是发育性和癫痫性脑病（DEE）患者对抗癫痫药物耐药，可能出现自主神经症状，如癫痫发作时明显的心动过缓和呼吸暂停，因此猝死风险增加。在此，我们报告了一例非常严重的SCN8A相关性癫痫，由于反复发作性心搏停止而需要植入心脏起搏器。

案例报告

患者是一名 14 个月大的女孩。出生后发生震颤和全身强直性癫痫发作。癫痫发作时出现心动过缓和口周发绀，继而发生心动过速和呼吸暂停后，出现明显的心动过缓和全身发绀，有时会导致发作期心脏停搏，需要心肺复苏。她的癫痫发作对抗癫痫药物无效。由于需要复苏的癫痫发作没有减少，因此在出生四个月后进行了心脏起搏器植入。外显子组测序揭示了 SCN8A 中的杂合从头变体( NM_014191.3 :c.4934T>C,p.(Met1645Thr))。即使苯妥英有效，心动过缓的癫痫发作仍然大约每月一次，并且观察到起搏器活动。

结论

据我们所知，这是首例报道的SCN8A相关 DEE 病例，其中进行了起搏器植入。与本例一样，起搏器植入应被视为SCN8A相关 DEE 危重患者的治疗选择，因为据报道SCN8A相关 DEE患者癫痫猝死的发生率约为 10% 。