VISUAL-EVOKED POTENTIALS IN LONG-TERM SURVIVORS OF ACUTE LYMPHOBLASTIC-LEUKEMIA IN CHILDHOOD

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 the rapy-related disturbances in conduction velocity capacities within cen tral nerve fibers. Subjects mere grouped with respect to CNS prophylax is: 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 follo w-up VEPs were abnormal in 10 subjects (10.9%) with comparable rates i n 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 significantlgr pro longed P100 latencies and had a 6.1-fold increased relative risk to de velop VEP disturbances. No correlation could be established between VE P outcome and illness- or treatment-related parameters. VEP outcome na s not correlated with age at diagnosis or gender. Thus, VEP recordings showed a close relationship with radiation-induced CNS white-matter d isturbances. However, their value for clinical practice, routinely per formed follow-up evaluations or standardized posttreatment surveillanc e studies is negligible.