Absence of later auditory brain stem response components, congenital horizontal nystagmus, and hypotonia in male infants.

Abstract

Five male infants, all of whom showed findings of wave I or waves I and II only of the auditory brain stem response (ABR), congenital horizontal pendular nystagmus, and hypotonia of head and limbs in the early infantile period with later paresis, are discussed. Their ages ranged from 3 to 13 months at the first examination, at which time neither head control, sitting, nor walking had been attained. Follow-up studies of ABRs revealed persistent abnormalities with neither remission nor progression. In spite of these abnormalities, these infants responded well to voices and other sounds. The congenital nystagmus in each case was demonstrated by electronystagmography to have a frequency of 2 to 3 Hz. The correlation between clinical signs and ABR is uncertain as yet. However, our findings are strongly indicative of nonprogressive inborn abnormalities in the lower brain stem.