Abstract
Visual-evoked potentials (VEPs) were studied in 92 asymptomatic long-term survivors
of acute lymphoblastic leukemia (ALL) in first complete remission 6-7 years after
cessation of therapy in order to detect therapy-related disturbances in conduction
velocity capacities within central nerve fibers. Subjects were grouped with respect
to CNS prophylaxis: a) ith. MTX and 18 Gy cranial irradiation (group A, n = 58), b)
ith. MTX and iv. MHD-MTX, no cranial irradiation (group B, n = 34). At follow-up VEPs
were abnormal in 10 subjects (10.9 %) with comparable rates in both CNS prophylaxis
groups (A: 7/58 [12.1 %], B: 3/34 [8.8 %]; p = 0.56). Participants with radiological
signs of leukodystrophy (n = 14), all within the irradiated CNS prophylaxis group,
showed significantly prolonged P100 latencies and had a 6.1-fold increased relative
risk to develop VEP disturbances. No correlation could be established between VEP
outcome and illness- or treatment-related parameters. VEP outcome was not correlated
with age at diagnosis or gender. Thus, VEP recordings showed a close relationship
with radiation-induced CNS white-matter disturbances. However, their value for clinical
practice, routinely performed follow-up evaluations or standardized posttreatment
surveillance studies is negligible.
Key words
Children - Leukemia - CNS prophylaxis - VEP - CNS late effects
