Neuropsychologic follow-up study of children with acute lymphocytic leukemia: A preliminary report

Thirty-three children with acute lymphocytic leukemia who were in remission and who did not have central nervous system (CNS) leukemia were studied in an effort to detect effects of CNS prophylaxis on brain function. Nineteen children had received intrathecal methotrexate plus cranial radiation, eight had intrathecal methotrexate alone, and six had intrathecal plus intravenous methotrexate. Intrathecal methotrexate, 12 mg/m², was given six times over 2 months. The dosage of cranial irradiation was 2400 rads in 12 divided doses over 16 days. Intravenous methotrexate, 500 mg/m², was given at 21-day intervals three times. All except two patients had been in remission for more than 1 year, 10 for 1–2 years, nine for 2–4 years, and 12 for more than 4 years. Computed tomography of the head, electroencephalograms, neurologic examination, and a modified form of the Halsted-Reitan neuropsychologic test battery revealed 13 patients with an abnormal finding, but only one of these patients had an abnormality in more than one area. There was thus no correlation between the observed structural and functional abnormalities. These preliminary results fail to confirm any significant difference in neuropsychologic function related to the various CNS regimens and do not indicate a need to modify presently accepted methods of CNS prophylaxis. A prospective longer-term follow-up study with a larger patient sample is needed to assess the long-range relationship of measurable abnormalities to CNS prophylaxis and to help establish a preferred method of prophylaxis.