Efficacy and prognosis of long-term, high-dose steroid therapy for Lennox–Gastaut syndrome

Objective: Lennox–Gastaut syndrome (LGS) is a severe form of developmental and epileptic encephalopathy that is highly resistant to treatment with conventional anti-epileptic drugs and non-pharmacological therapies. In the present study, we aimed to investigate the efficacy of long-term, high-dose steroid therapy and its effect on prognosis in children with LGS. Methods: This prospective study included patients with LGS who received long-term, high-dose steroid therapy beginning in November 2016. Prednisolone (60 mg per day) was administered for 2 weeks, following which the dosage was reduced to 60 mg on alternate days for 12 weeks. The drug was then slowly tapered over the next 3 months. The primary outcome was a reduction in seizure frequency relative to baseline at 14 weeks. The secondary outcome was whether patients had become seizure-free at 1 year. Results: Among 44 patients, 30 (68.2%) experienced a reduction in seizure frequency of more than 50%, including 26 (59.1%) with complete seizure control who were classified as the responder group. The remaining 14 (31.8%) were classified as the non-responder group after 14 weeks of treatment. Twenty patients (45.5%, 20/44) remained seizure-free after 1 year of treatment. However, 10 patients (33.3%, 10/30) in the responder group relapsed within a year. Improvements in electroencephalography (EEG) findings tended to be consistent with seizure outcomes. All patients had side effects of weight gain and Cushing's face, but most adverse effects were mild and transient. Conclusion: Long-term, high-dose steroid therapy can be considered an effective treatment option for children with intractable LGS.