Findings in computerized axial tomography after intrathecal methotrexate and radiation.

Medulloblastoma and acute lymphocytic leukemia patients treated by intrathecal methotrexate and radiation were investigated by means of computerized axial tomography. More than 50% of them turned out to have acquired encephalopathy. Only gross morphologic brain defects, as visualized by computerized tomography, caused manifest clinical signs of brain dysfunction, such as epilepsy, mental retardation, paresis, and apallic syndrome. Mild morphologic changes were found even in asymptomatic children. The preferred site of defects in brain substance was the paraventricular white matter.