Abstracts

Rationale: Infantile spasms (IS) is an intractable epileptic encephalopathy characterized by epileptic spasm, hypsarrhythmia, and psychomotor retardation with various etiology. The purpose of this study is to investigate the efficacies of the different treatment modalities including antiepileptic drugs (AED), ketogenic diet and surgical operations according to underlying etiologies.Methods: We performed a retrospective analysis of therapeutic outcomes from AEDs with single or multiple add-on treatment, ketogenic diet (KD), and surgical treatments in patients with IS. All patients in the study were treated in Severance Children s Hospital for more than 6 months from January, 2004 to June, 2010. AEDs included in this study were vigabatrin, prednisolone, topiramate, zonisamide, clobazam, valproate, levetiracetam, lamotrigine, and pyridoxine. The etiology was categorized into cryptogenic and symptomatic that was subsequently sub-categorized into malformation of cortical development, destructive encepalopathy, metabolic causes, and unknown causes. Efficacies of treatment modalities were also measured according to underlying etiologies.Results: Of total 395 patients with IS, 298 (75.4%) had symptomatic etiologies, and 97 (24.6%) were cryptogenic group. Among 298 patients with symptomatic etiology, 79 had malformation of cortical development, 132 had destructive encepalopathy, 34 had metabolic causes, and 53 had unknown causes. The average number of treatments applied to patients was 4.1. Overall, 78.0% of the patients (76.2% of symptomatic etiologies and 83.5% of cryptogenic etiology) became spasm-free. Spasm-free outcome of vigabatrin was 24.7% (69 out of 368 patients) with an average dose of 93.3 mg/kg. Oral prednisolone showed spasm-free rate in 19.8% (24 out of 121 patients) with the highest rate in patients with destructive encephalopathy (26.5%). Topiramate showed 17.2% spasm-free rate (32 out of 186 patients), and the highest rate was seen in the patients with destructive encephalopathy (28.3%). Zonisamide showed spasm-free rate in 16.8% (20 out of 119 patients). Clobazam showed spasm-free rate in 11.5% (24 out of 209 patients). Valproate showed spasm-free rate in 11.3% (18 out of 159 patients). Levetiracetam showed spasm-free rate in 8.9% (4 out of 45 patients). Lamotrigine showed spasm-free rate in 8.2% (4 out of 49 patients). No patients became spasm-free using pyridoxine. In addition, 150 patients (38.0%) were on ketogenic diet, and 55 patients (36.7%) became spasm-free. Total 19 patients underwent resective surgeries resulting in 78.9% (15 out of 19 patients) of spasm-free outcome. Conclusions: AEDs showed variable outcomes to control IS with limited success rate. Surgery was most effective in selected cases, and KD showed higher efficacy than other AEDs.