The latency of the visual evoked potential as an index of myelin disturbance in children treated for acute lymphoblastic leukemia.

The phase of central nervous system prophylaxis using cranial irradiation and intrathecal chemotherapy during the treatment of childhood leukemia, may disturb myelination. It has been suggested that this disturbance may be permanent in some children. In this study we report the visual evoked potentials from flash and pattern stimuli in 29 children who were in long-term hematological remission following treatment for acute lymphoblastic leukemia, and who were attending normal schools. We compared these to 29 control children who were matched for age, sex and social class. No difference was detected in the latencies of the response, and we conclude that we could demonstrate no permanent disturbance of myelination by this technique in these long-term survivors.