Methotrexate-induced leukoencephalopathy is treatable with high-dose folinic acid: a case report and analysis of the literature.

An episode of leukoencephalopathy is reported in a 13-year-old girl who, after standard radiotherapy for a posterior fossa medulloblastoma, received 8 treatments with a protocol containing a 4-hour infusion of 500 mg/m2 methotrexate and 12 mg intrathecal methotrexate. The leukoencephalopathy, documented clinically and by CT and EEG, cleared after 2350 mg of leucovorin (citrovorum factor, folinic acid) was given in addition to the 135 mg given as part of the therapy. A review of the literature suggests that leukoencephalopathy may be prevented by high doses of leucovorin and can be treated by high doses, if lower doses were used initially. When high dose leucovorin was not used, residual neurological damage is not unusual.