Abstracts

Rationale: SCN2A mutations present with an array of different phenotypes including early infantile epileptic encephalopathies, which are often refractory to treatment. We present a patient with malignant migrating partial seizures of infancy (MMPSI) with an SCN2A mutation whose super-refractory status epilepticus (SRSE) was terminated with high-dose steroids with continued seizure freedom achieved on oral antiepileptic drugs (AEDs). Methods: Case report and literature review Results: Female neonate born at 39 weeks via uneventful spontaneous vaginal delivery with seizures starting at 4 hours of life and progressing over 1.5 months to SRSE. Typical seizures were manifested by gaze deviation, tonic posturing, and hemibody jerking (right or left) often with associated apnea. On EEG seizures originated independently from either hemisphere and frequently moved back and forth between hemispheres. Infectious and metabolic workup, MRI brain, chromosomal microarray, and workup for pyridoxine-responsive epilepsy and GLUT-1 deficiency were unrevealing. Epilepsy gene panel showedSCN2A mutation (c.685T>G [p.Ser229Ala]). AEDs tried include phenobarbital (PB), levetiracetam (LEV), oxcarbazepine, fosphenytoin and phenytoin, lacosamide, lorazepam, clonazepam, and clobazam (CLB). Intravenous (IV) pyridoxine and folinic acid were ineffective. Ketogenic diet was tried but patient developed an ileus requiring cessation of oral feeds.Despite above therapies, patient continued to have frequent seizures with apnea necessitating resuscitation. She was intubated, placed on continuous EEG, and started on a midazolam drip (max dose 2 mg/kg/hr) but seizures continued. She was switched to pentobarbital (PTB) drip (max dose 6.5 mg/kg/hr) followed by concurrent ketamine drip (max dose 8 mg/kg/hr) but continued to have seizures despite complete EEG suppression between seizures. IV methylprednisolone (10 mg/kg/day twice daily for 5 days) was started with a subsequent decline in seizures and followed by a 10-day prednisolone taper. PTB was weaned over 2 days and ketamine over 2.5 weeks. Topiramate (TPM) was started during the ketamine taper for increased seizures. 24 hour EEG following steroid course was without seizures. She was discharged on PB, CLB, LEV, and TPM. At outpatient follow up patient was seizure-free for over 3 months, though had hypotonia and significant developmental delay. Conclusions: To our knowledge, this is the first reported case of MMPSI with resolution of SRSE with intravenous high-dose steroids accompanied by subsequent sustained seizure freedom on oral AEDs. Thus, treatment of SRSE with intravenous high-dose steroids in patients with an MMPSI phenotype or possibly in other phenotypes associated with SCN2A mutations may be efficacious and should be considered. Funding: None