Topiramate use for maintenance antiseizure therapy in children with hematologic malignancies experiencing posterior reversible encephalopathy syndrome during chemotherapy: a single-center retrospective study

Seizures are a predominant symptom in posterior reversible encephalopathy syndrome (PRES) occurring in the context of chemotherapy. However, anti-seizure medications (ASMs) selection remains challenging due to potential pharmacokinetic interactions with chemotherapeutic agents. This descriptive retrospective study reports our institutional experience with ASMs, particularly topiramate (TPM), in children with hematologic malignancies who developed PRES during chemotherapy. We retrospectively reviewed the clinical data of pediatric patients with hematologic malignancies who developed PRES during chemotherapy at our institution between January 1, 2011, and December 31, 2024. We assessed the characteristics of PRES, ASMs use, and observed outcomes. The criteria for initiating maintenance ASMs therapy were defined as more than two seizures within 24 h or more than three seizures within three days, reflecting a clinician-assessed higher risk of further seizures. Nineteen children developed PRES during chemotherapy. Seizures occurred in 17 patients. Among the 11 patients treated with maintenance ASMs for recurrent seizures, 8 received TPM (median dosage 3 mg/kg/day) and 3 received levetiracetam (LEV) (median dosage 35 mg/kg/day). No serious adverse events related to ASMs were documented. All 8 TPM-treated patients completed their planned chemotherapy, however, one patient required reintroduction of TPM after discontinuation and developed secondary epilepsy. Of the 3 LEV-treated patients, one died from cancer relapse after being unable to tolerate subsequent chemotherapy due to persistent neurological deficits. Six patients with a single seizure did not receive maintenance ASMs. Two of these patients died from cancer relapse after being unable to tolerate chemotherapy. In this small, descriptive retrospective cohort, TPM was well-tolerated in children with hematologic malignancies who developed PRES during chemotherapy and was administered to patients who completed their chemotherapy courses. The favorable pharmacokinetic profile of TPM offers theoretical advantages in this population. However, due to the study’s retrospective, non-randomized design, limited sample size, and inherent selection bias, these findings are hypothesis-generating and descriptive. Prospective validation is needed to explore the role and potential benefits of TPM in this context.