Abstracts

Rationale: Lennox-Gastaut syndrome (LGS) is a severe epileptic encephalopathy that is highly refractory to conventional anti-epileptic drugs and non-pharmacological therapies. Several treatment algorithms have been proposed for LGS, including valproate primary treatment and non-pharmacological treatments such as ketogenic diet, epileptic surgery, and vagus never stimulation. However, steroid treatment was usually not included in priority treatment. Over the last 50 years, corticosteroids and ACTH have been recognized as first line or second line treatments in infantile spasms. Therefore, in LGS starting with the assumption that steroid and ACTH would be effective, prednisolone treatment showed seizure free at 60-70% immediately after treatment. However, subsequent studies have shown a high recurrence rate of 45-70% within 3 to 6 months after initiation of treatment. This study aimed to investigate the efficacy and prognosis of high dose steroid therapy in children with LGS. Methods: We retrospectively analyzed medical records of patients with LGS treated by high dose steroid therapy from November 2016 to February 2019 at Severance Children's hospital, Yonsei University College of Medicine. Patients aged one month to 18 years were included. A high dose steroid schedule of prednisolone was to administer 60mg per day for 2weeks and 60mg on alternate days for 3 months with previously prescribed anti-epileptic drugs. The seizure frequency and percentage reduction compared to baseline, adverse events, and epilepsy gene panel were studied. At 14 weeks, seizure frequency was examined as primary outcome. At 14 weeks, when the seizure reduction was reduced by more than 50% compared to the baseline seizure frequency, we considered the responder group. Results: Among 46 children, half of patients had failed treatment with three or more previous anti-epileptic drugs. Twenty-two patients (47.8%) had failed treatment with ketogenic diet and 4 patients underwent epileptic surgery. After 14 weeks of high dose steroid therapy, 65.2% (n=30) of patients showed a reduction in seizure frequency more than 50%, and 54% (n=25) of patients became seizure free. Especially, this therapy showed good response in patients with channelopahties confirmed in the epilepsy gene panel. However, among the responders with a reduction in seizure frequency more than 50%, 10 patients (24%) relapsed within 12 months. Four patients had a good effect on the high dose steroid therapy but discontinued treatment due to side effects such as infection and lethargic condition. Conclusions: High dose steroid therapy can be considered as an effective treatment option for intractable Lennox-Gastaut syndrome in children. Funding: No funding