Abstracts

Rationale: To clarify seizure and developmental prognosis of children with epileptic encephalopathy in infancy and early childhood comparing surgical versus medical treatment. Methods: An international multicenter observational cohort study was undertaken for children with medically intractable epilepsy admitted in 13 collaborative pediatric epilepsy centers in 3 east-Asian countries between April 2009 and March 2010. Inclusion criteria was children under 6 years old on admission with daily disabling epileptic seizures not suppressed or recurred in spite of intensive medical treatment including antiepileptic drugs (>2 major drugs), ACTH and/or Ketogenic diet. Clinical pictures of registered patients were reported previously (Oguni et al., Brain Dev 2013). On registration, 317 children were recruited, among which 250 were medically treated (medical group), 31 underwent resective surgery (resective group), and 36 underwent palliative surgery (palliative group). Seizure and developmental outcome was obtained in 272 children at one year and 232 children at 3 years after discharge. Seizure free survival time from discharge to recurrence was analyzed using Cox proportional hazard model adjusted by gender, age of admission, age of seizure onset, age of initial anti-epileptics administration, major etiology, epilepsy syndrome, EEG findings, and seizure type. Change of developmental quotient (DQ) from baseline to 3-year follow-up was analyzed by adjusting for DQ at baseline, gender, age of admission, age of seizure onset, age of initial anti-epileptics administration, major etiology, epilepsy syndrome, EEG findings, and seizure type (ANCOVA). Results: Using Kaplan-Meier method, median seizure-free survival time was 1140 (95%CI: 428, 1140) days in resective group, 397 (95%CI: 370, 836) days in palliative group, and 395 (95%CI: 388, 413) days in medical group. Hazard ratios of resective group and palliative group versus medical group were 0.401 (95%CI: 0.220, 0.731) and 0.629 (95%CI: 0.403, 0.982), respectively. Seizure-free survival time in children undertaken surgery was significantly long compared to medical treatment. At 3-years (1080 days) after discharge, seizure free survival rate with Kaplan-Meier method were 52.4% in resective group, 32.1% in palliative group and 15.7% in medical group (Fig. 1). Least square means of the difference of DQ change from baseline to 3-year follow-up were smaller in surgery group; i.e., -0.44(SE:5.12) in resective, -5.99(SE:4.69) in palliative and -7.93(SE:2.19) in medical group, although statistically not significant. In medical group, 5 deaths were reported by 3-year after discharge. In surgical group, no death was reported. Conclusions: The results suggest that surgical treatment for children with intractable epileptic encephalopathy in infancy and early childhood can yield better seizure and development prognosis comparing to medical treatment only. Early identification of surgically remediable patients may be essential.