The acid-base balance homeostasis reflected by urine pH in children with infantile epileptic spasm syndrome may be associated with response to adrenocorticotropic hormone treatment: a retrospective cohort study.

Background: Infantile epileptic spasms syndrome (IESS) is an age-related developmental and epileptic encephalopathy. Adrenocorticotropic hormone (ACTH), one of the first-line treatment, has its efficacy influenced by multiple factors. This study aimed to investigate and analyze clinical variables (pre-treatment clinical data, serum and urine routine test) in children with IESS to predict outcomes after the first ACTH treatment. Furthermore, the potential impact of underlying factors on ACTH efficacy was assessed. Methods: A total of 186 children who received ACTH treatment for the first time in the Pediatric Department of The First Medical Center of the Chinese PLA General Hospital from January 2018 to June 2023 were retrospectively evaluated. They were divided into the responsive group and the non-responsive group according to the clinical outcomes after treatment. The clinical data of the two groups were compared, followed by logistic regression analysis to evaluate the relationship between the factors and ACTH treatment outcome. Results: The lead time between the first spasm onset and ACTH treatment initiation was significantly shorter in the responsive group compared with the non-responsive group. Additionally, more patients experienced epileptic spasms after the age of 3 months and responded significantly better to ACTH treatment than those whose spasms began within the first 3 months. Compared to children with IESS of unknown etiology, patients with congenital genetic abnormalities without structural abnormalities were less likely to have a short-term response to ACTH treatment. Despite no significant differences in serum sodium, potassium, calcium, and chloride levels between the two groups, pre-treatment serum inorganic phosphate levels were correlated with ACTH efficacy. The responsive group had significantly higher pre-treatment urinary pH levels. Conclusions: IESS patients should receive first-line treatment immediately after spasm onset. The age of epileptic spasms onset and its etiology may help predict the efficacy of ACTH treatment. Serum inorganic phosphate levels and urinary pH levels seem to play an important role in the treatment of IESS with ACTH, and they may have indicative significance for precision treatment.