Predictive factors for relapse of epileptic spasms after adrenocorticotropic hormone therapy in West syndrome

Purpose: To investigate whether serial electroencephalographic (EEG) findings can predict relapse of epileptic spasms after synthetic adrenocorticotropic hormone (ACTH) therapy in patients with West syndrome (WS). Subjects and methods: Thirty-nine WS patients (8 cryptogenic and 31 symptomatic) were included in this study. These patients received ACTH therapy for the first time and were regularly followed up for more than three years at our hospital. Sixteen patients (41.0%) showed seizure relapse (relapse group) and 23 patients (59.0%) did not show relapse (non-relapse group). We used survival analysis to investigate the influence of etiology and presence of epileptic discharges after the ACTH therapy on seizure outcome. Results: Immediately after the ACTH therapy, etiology was associated with seizure outcome (p = 0.003). In the early stage (1 month after the ACTH therapy), only the presence of epileptic discharges (p = 0.001) had a significant association with seizure outcome, regardless of etiology. Because all relapsed patients were in the symptomatic group, we performed the same statistical analysis on symptomatic WS patient data only. We found that the group with no epileptic discharges on EEG showed a significantly higher seizure-free rate than those with epileptic discharges in the early stage (p = 0.0091). Conclusion: This study demonstrated that serial EEG findings after ACTH therapy are significantly related to relapse of epileptic spasms.