Comparison of adrenocorticotropic hormone efficacy between aetiologies of infantile spasms

Purpose: We aimed to study the efficacy of adrenocorticotropic hormone (ACTH) treatment on infantile spasms with different aetiologies. In particular, we were interested in patients with structural-acquired aetiology. Methods: Patients with infantile spasms, who were treated with ACTH, were divided into three groups based on the aetiologies: unknown aetiology with normal development (unknown-normal), structural-acquired, and combined-congenital aetiologies that included genetic, metabolic, structural-congenital, or unknown aetiology with developmental delay. Results: Of the 107 patients included (58 males, 49 females), 25 patients had unknown-normal aetiology [median age at onset 5 months, standard deviation (SD) 3.12, range 2-16 months]; 20 patients had structural-acquired aetiology (median age at onset 6.5 months, SD 3.85 months, range 4-17 months); and 62 patients had combined-congenital aetiologies (median age at onset 5 months, SD 2.73 months, range 2-16 months). The efficacy of ACTH was 64.0 %, 65 %, and 30.6 % in the unknown-normal aetiology, structural-acquired aetiology, and combined-congenital aetiologies, respectively (p < 0.01). Multivariate analysis showed a statistically significant higher efficacy in the unknown-normal aetiology [Odds ratio (OR) 4.63, 95 % confidence interval (CI) 1.60-13.30] and structural-acquired aetiology (OR 3.41, 95 % CI 1.01-11.50) compared to that in the combined-congenital aetiologies. Conclusion: Infantile spasms with structural-acquired aetiology had greater response to ACTH treatment than those with combined-congenital aetiologies. The efficacy of standard therapy of infantile spasms should be considered based on aetiology.