IN SPITE of the progress in treatment of childhood leukemia, the control of meningeal leukemia remains a problem. The blood brain barrier prevents the penetration of the antileukemic drugs into the central nervous system (CNS)1-5 and the anatomical geography of the cerebral gyri renders leukemic cells inaccessible to drugs injected into the subarachnoid space. When the antileukemic drug is given intrathecally, it often fails to eradicate malignant cells completely, as shown by the frequent reappearance of blasts in the cerebrospinal fluid (CSF) and by the persistence at postmortem examination of leukemic infiltrate in the CNS.6
The clinical picture of meningeal leukemia varies in the extent and severity of the neurological symptoms and signs. Headache, nausea and vomiting, drowsiness, and irritability are the most frequent symptoms; papilledema, cranial nerve palsies, and separation of the cranial sutures are the most common signs. Headache when present can be of an extreme