A 10 year boy was admitted to our hospital because of lumbago and fever in July, 1985. Physical findings included no pallor and no petechia. The white cell count on admission was 7400/μl with 17% blast cells and bone marrow examination was interpreted as diagnosis of acute lymphocytic leukemia, L1 type in FAB classification.
Complete remission was induced by a combination chemotherapy of vincristine, cyclophosphamide and prednisolone. Intensification therapy was consisted of vincristine, given 12 hours later with high dose intravenous methotrexate (HD-MTX).
Five days after the 4th course of vincristine and HD-MTX therapy, he suddenly had generalized tonic convulsion and became loss of consciousness. These neurological signs were gradually resolved and within 5 days after the onset of symptoms he became neurologically normal. Laboratory values included platelet count of 9.4×104/μl and a lumbar puncture with an opening pressure 90 mmH2O, contents of protein and sugar of 19 mg/dl, of 82 mg/dl respectively and no cells. MTX level in cerebrospinal fluid was not detected by an enzyme immunoassay. Electroencephalography disclosed bilateral slowing with left parieto-temporo-occipital accentuation. Computed tomography of noncontrast enhancing of brain showed edema and a high density lesion in the left sylvian fissure, but 20 days after revealed no abnormal findings.
