Computer assisted tomography in methotrexate encephalopathy.

Five children with acute lymphocytic leukemia (ALL) developed encephalopathy following treatment with intrathecal or intraventricular methotrexate (MTX). In these patients computer assisted tomography was informative by revealing areas of decreased attenuation coefficient located periventricularly and in each centrum semiovale (three cases) and calcifications, mostly in the deep and cortical gray matter (two cases), as well as ventricular dilatation (four cases). Contrast injection used in one of these five patients, as well as in another child (not affected by ALL) with MTX encephalopathy, failed to reveal enhancement.