A double blind study of vitamin B6 in Down's syndrome infants. Part 2--Cortical auditory evoked potentials.
Cortical auditory evoked potentials (CAEPs) were recorded at 1 and at 3 years of age in 19 children with Down's syndrome participating in a double blind trial of vitamin B6 and placebo begun in early infancy and continued for 3 years. CAEPs have previously been shown to have abnormally high amplitude in Down's syndrome patients. The CAEPs of the patients in the B6-treated and placebo groups were compared. Only minor effects were found in the CAEPs recorded at 1 year of age. At 3 years of age, however, comparison of the B6-treated group and the placebo group revealed significant differences in both amplitudes and latencies of CAEP components. Peak to peak amplitudes of prominent components were significantly lower in B6-treated patients than in their placebo controls. Amplitude correlated in some cases with whole blood serotonin levels. Latencies for several prominent evoked peaks were significantly longer in B6-treated patients.