 Patients with CNS leukemia CNS-2, CNS-3, or traumatic lumbar puncture LP with blasts on initial LP receive additional IT cytarabine twice weekly beginning on days 4-6 and continuing until cerebrospinal fluid CSF is clear, followed by 2 additional doses. Patients with cranial nerve palsy but no leukemia blasts in CSF or leukemic eye infiltrates also receive additional IT cytarabine as above. 