Abstracts

Rationale: Clinical features and long-term seizure and developmental outcomes of the surgical cases of infants under one year of age are not fully elucidated. Is the early surgical treatment safe and effective for such infants with epileptic encephalopathies? There are no reports of large cases on these issues. We studied these issues from our experience in a tertial epilepsy center. Methods: Between April 1999 and March 2015, 622 patients with epilepsy underwent epilepsy surgeries, in which 58 cases were infants under one year of age at the surgery. Age at onset, age at surgery, epileptic syndrome, etiology, surgical procedures, complications, and seizure and developmental outcomes were studied. Developmental outcome was evaluated by Kinder Infant Developmental Scale, Tanaka-Binet Developmental Test or WISC IV. The outcomes were periodically evaluated, and the last evaluation was done at 1year 3 months and 14 years 2 months of age, which were 1 year and 13 years and 7 months after surgery. Presurgical evaluation included long-term video-EEG monitoring, MRI, 18F-FDG-PET, interictal and ictal 99mTc-ECD-SPECT and SISCOM, and MEG. No invasive monitoring was adopted. Results: Seizures started at two hours after birth to 3 months of age, mostly < 1 month. The patients had hourly or daily seizures at surgery. They underwent epilepsy surgery at 58 days of life to 10 months of age with body weight 3.8 and 9.5 kg. Twenty-three cases had Ohtahara syndrome (OS), 12 cases had infantile spasms (IS), and 23 cases had other intractable epilepsies. The etiology consisted of hemimegalencephaly (HME) in 22 cases, multilobar dysplasia (MLD) in 17, focal cortical dysplasia (FCD) in 13, brain tumors in 3, Sturge-Weber syndrome in 1, and MRI-negative in 2. Surgical procedures included vertical hemispherotomy (HS) for 24 cases, multilobar resection/posterior or anterior disconnection (MLR/Discon) for 14, focal resection (FR) for 18 and total callosotomy for 2. Complications occurred in 10 cases: hydrocephalus required shunt placement in 6 cases (HS 3, MS/Discon 2, and FR 1), transient electrolytes abnormalities in 3 (HS 3), and focal infarction in 1 (FR 1). There was no dead case after surgery. At the last evaluation, seizure outcome by Engel class I, II, III and IV were 45, 2, 5, and 6 cases, respectively. Class I, II, III and IV were obtained in 18, 0, 3 and 2 cases in OS, 6, 1, 2 and 3 cases in IS, and 21, 1, 0 and 1 cases in others. Class I, II, III and IV were 17, 0, 3 and 2 cases in HME, 15, 1, 0 and 1 case in MLD, and 9, 1, 1 and 2 cases in FCD. Class I, II, III and IV were obtained in 19, 0, 3 and 2 cases by HS, 13, 1, 0 and 0 cases by MLR/Disco, and 13, 1, 1 and 3 cases by FR. Callosotomy resulted in only class III and IV one each. IQ/DQ was >80 in 9 cases, 79-70 in 2, 69-50 in 16, 49-35 in 5, 34-20 in 12, and < 20 in 14. IQ/DQ in OS/IS was >70 in 1/4 cases, 69-50 in 4/3, 49-35 in 2/1, 34-20 in 9/1, and < 20 in 7/3. Conclusions: Surgical cases of infants under one year of age had very early onset and severe epilepsies with extremely frequent seizures, and almost all of them had cortical dysplasia. They required big epilepsy surgery, but early surgery could be done without invasive monitoring because of MRI-positive etiology, and the seizure outcome was excellent and complications were not frequent and not severe. Developmental outcome was encouraging despite the etiology and epileptic encephalopathies. We do not hesitate to do early surgery for epileptic encephalopathies with cortical dysplasia. Funding: None