Use Cytarabine, Methotrexate, and CAR-T Neurotoxicity to guide the working diagnosis and next step; let the main risk or management issue drive escalation, treatment choice, and follow-up.

High-dose cytarabine can trigger an acute, dangerous cerebellar syndrome that unfolds right during the active infusion.; Single most frequent and dose-limiting toxicity is severe ototoxicity, which can lead to permanent hearing loss.; When administered intrathecally, it can manifest as an acute aseptic meningitis or a rapid presentation of posterior reversible encephalopathy syndrome.; CRS is a highly predictable, systemic inflammatory reaction triggered by the rapid expansion of chimeric antigen receptor T-cells.; Methotrexate can cause a severe, acute transverse myelitis, which will show up on a magnetic resonance imaging scan as significant swelling of the spinal cord.