BRAIN-STEM AUDITORY AND VISUAL-EVOKED POTENTIALS IN INFANTS WITH MYELOMENINGOCELE

Brainstem auditory evoked potentials (BAEPs) and visual evoked potenti als (VEPs) were recorded in 47 infants with myelomeningocele to determ ine if the evoked potentials reflected the early neurological status, and if they had prognostic value as to the children's neurological out come. The infants were tested between 1 day and 3 months of age (mean 24 days), while still in hospital after the myelomeningocele repair. O utcome was assessed at a mean of 2 years of age. Normal BAEPs were fou nd in 41% and normal VEPs in 62% of the patients, BAEPs were abnormal in all infants studied who had symptomatic Amold-Chiari (AC) malformat ion (n = 9); VEPs were abnormal in only 55% of symptomatic infants. Of the infants who did not have symptomatic AC malformation, 53% had nor mal BAEPs, 69% had normal VEPs. Of the patients with normal BAEPs, 81% had normal cerebral function on follow-up. Of the patients with abnor mal BAEPs, 87% had central neurological abnormalities on follow-up. Of the patients with normal VEPs, 63% were normal on follow-up; of the p atients with abnormal VEPs, 71% were abnormal on follow-up. Thus, the VEPs studied early in the neonatal course do not appear to be sufficie ntly sensitive to be valuable prognostically in these infants. However , the BAEPs were consistently abnormal in symptomatic AC malformation and showed a positive predictive value of 88% and an accuracy in predi cting central neurological sequelae of 84%.