Neurophysiological abnormalities in adolescents with type I Crigler-Najjar syndrome.

We report neurophysiological abnormalities in two adolescents with type I Crigler-Najjar syndrome, an autosomal recessive disorder characterized by severe unconjugated hyperbilirubinemia. Electroencephalograms (EEGs) demonstrated frequent generalized single and polyspikes, and background slowing. Normal pattern reversal evoked responses (PRVERs) and normal central brain-stem auditory evoked responses (BAERs) were recorded in both patients. These findings differ from the EEG triphasic wave pattern seen in the EEG in hepatic encephalopathy and the central BAER abnormalities seen in many infants with kernicterus. Thus these findings most likely result from complex multifactorial processes and are not simply the result of the hyperbilirubinemia which is common to all 3 conditions.