White matter changes on MRI during treatment in children with acute lymphoblastic leukemia: Correlation with neuropsychological findings

Background. Treatment of childhood acute lymphoblastic leukemia (ALL) may c ause structural and functional brain damage. To find out the incidence of w hite matter changes during therapy, a prospective MRI study was designed, a nd the findings were correlated with neuropsychological evaluation. Procedu re. Thirty-three children with ALL underwent serial cranial MRI before, dur ing, and after therapy. Twenty-eight of these children underwent also neuro psychological assessment at the end of treatment. They all received intrave nous and intrathecal methotrexate for central nervous system (CNS) therapy, 15 patients received cranial irradiation in addition. Results. Transient h igh-intensity white matter changes were observed by MRI in three children 9 % (95% CI, 2-24%) who received chemotherapy-only. The high-intensity change s were most prominent in the frontal lobes in two of these children. The ch ildren with white matter changes were significantly younger than those with normal MRI (2.8 vs. 7.4 years; mean). There was no correlation between neu ropsychological tests and white matter changes, except in attention and in tests referring to the frontal areas in general. Conclusions. White matter changes are occasionally observed during therapy with the current Nordic pr otocols. Young children may be more susceptible to developing white matter changes after repeated intravenous methotrexate injections. There is no sys tematic correlation between neuropsychological deficits and MRI findings. ( C) 2000 Wiley-Liss, Inc.