Evaluation and Management of Acute-Onset Hemiparesis in an Adolescent With Leukemia.

Emergency departments (EDs) are alert to the possibility of stroke and the need for early interventions to improve long-term clinical outcomes. However, new-onset hemiparesis in pediatric patients with leukemia may be due to a number of different etiologies, including most common side effects from chemotherapeutic agents. We present a case of a 15-year-old boy with pre-B acute lymphoblastic leukemia on chemotherapy, having recently received a high-dose methotrexate infusion in addition to intrathecal methotrexate therapy, who presented to our ED with acute right-sided hemiparesis. He was initially suspected as having a possible ischemic stroke. Magnetic resonance imaging (diffusion-weighted and fluid-attenuated inversion recovery sequence) demonstrated focal areas of diffusion restriction, an early sign of delayed-onset methotrexate neurotoxicity. Our patient received appropriate supportive care and leucovorin rescue with gradual clinical recovery, after a prolonged hospitalization and acute care rehabilitation over the course of several months. Our case illustrates the need for ED providers to consider methotrexate neurotoxicity in pediatric oncology patients presenting with acute neurologic changes.