Recurrent intrathecal methotrexate induced neurotoxicity in an adolescent with acute lymphoblastic leukemia: Serial clinical and radiologic findings.

Systemic and intrathecal methotrexate (MTX) are integral components of acute lymphoblastic leukemia (ALL) therapy, but can be associated with neurotoxicity. We describe here the case of an adolescent male with T-cell ALL who developed recurrent episodes of subacute neurotoxicity characterized by slurred speech, emotional lability, and hemiparesis after intrathecal MTX administration. Serial magnetic resonance imaging with diffusion-weighted imaging showed recurrent areas of restricted diffusion within cerebral hemispheric white matter, which correlated chronologically with the administration of intrathecal therapy and severity of clinical symptoms. Resolution of diffusion abnormalities did not preclude further toxicity and a large lesion could cause persisting symptoms. (c) 2008 Wiley-Liss, Inc.