Hypotonia, congenital nystagmus, ataxia, and abnormal auditory brainstem responses: a report on the first white patient

Abstract

A white Italian boy, aged 5 years and 8 months, is reported with failure to thrive, hypotonia, truncal ataxia, psychomotor retardation, and congenital horizontal pendular nystagmus with only waves I and II on auditory brainstem responses. Our patient's clinical picture resembles that previously reported in 10 male Oriental patients. He did not manifest spastic diplegia by the age of 2 years, as did the subjects reported in the literature, but knee‐jerk hyperreflexia was evident at the most recent clinical reevaluation. Serial brain MRI studies revealed a cystic brain lesion and peritrigonal hyperintensities with no brainstem abnormalities. To date, no other child with a similar syndrome has been described either in Europe or in America. The clinical features of this condition are consistent and characteristic. A definitive diagnosis is achieved by demonstrating the absence of all waves following wave I or wave II on auditory brainstem responses as early as 3 months of age. Due to the predominance of males, the occurrence in siblings, the early age at onset, the non‐progressive course, and the characteristic auditory brainstem response findings, the syndrome may have a genetic origin and be attributable to a dysgenetic brainstem lesion.