Long-term observation of the changing brainstem auditory evoked potentials in a case of infantile opsoclonus-polymyoclonia syndrome.

Brainstem auditory evoked potential (BAEP) studies were repeatedly carried out on a boy with infantile opsoclonus-polymyoclonia syndrome, from 15 months to 39 months of age, the following being revealed: the I-III interpeak latency (I-III IPL) was more or less in the upper normal range until 24 months and then remained at the same level throughout the rest of the observation period, not showing physiological shortening with maturation. It should be noted that the prolongation of I-III IPL continued in spite of the disappearance of the opsoclonus.