Investigators at Tokyo Women's Medical University studied the clinical, radiological, and EEG characteristics of 69 patients with infantile spasms (IS) followed for 3-74 months (mean 18 months) after initial cessation of epileptic spasms (ES). Subjects were classified as focal (fIS)(n=23) and diffuse (dIS)(n=46). ES responded to the initial ACTH trial in 100% fIS vs 80% of dIS (p=0.02). Subsequent seizure relapse occurred in 74% fIS cf 38% of the dIS group (p=0.0006). A second ACTH course of therapy in fIS group resulted in a short- or long-term remission. Approximately one-third of fIS patients maintained remission despite focal epileptic EEG abnormalities. Focal resection and corpus callostomy achieved only a short-term remission. Grouping patients as fIS and dIS provides practical information regarding long-term outcome and treatment strategies. [1]
COMMENT. The authors conclude that a second course of ACTH should be considered to treat a relapse of fIS before resorting to surgical therapy. An extremely low-dose ACTH step-up protocol is used to treat West syndrome (WS) in this institution [2]. In an earlier report of 31 infants with WS (cryptogenic WS in 9, symptomatic WS in 22) using ACTH-Z in a dose of 0.005 mg (0.2 IU/kg/day) once daily for at least 2 weeks, up to a maximum of 3 weeks, tapered to zero over the subsequent 1 or 2 weeks, successful control of both spasms and hypsarrhythmia was obtained in 17 patients (55%). In the absence of a response, the dosage was increased to 0.025 mg (1.0 IU/kg/day) for 2 weeks (second treatment course in 8 patients), providing complete suppression of WS in an additional 2 patients. At 1 year or more follow-up, 13 patients (48%) remained seizure-free. Side effects were mild and occurred in 13 patients. This ACTH extremely low-dose step-up method achieved 61% short-term and 48% long-term remission, without significant side effects. The efficacy of low-dose versus high-dose ACTH regimens continues to be debated. [3; 4; 5]