Neurophysiological evaluation of newborns with congenital hydrocephalus.

EEGs and visual and auditory evoked potentials (VEP and AEP) were studied in 27 newborns with congenital hydrocephalus. Asynchronous sleep patterns were the main EEG abnormality in the newborn as well as in the older infants and children. Asynchronous tracé alternant patterns, the most common finding, were more frequently encountered in infants with more severe hydrocephalus. Asynchrony of bifrontal humps was another finding observed in a few infants. Intermittent semirhythmic theta or delta waves were noted in some infants. Depression of the EEG background activity was an infrequent finding observed in more severe hydrocephalus. VEP showed prolonged latency in 60% of cases, but its wave form was normal in most cases, even sometimes in patients with highly abnormal EEGs. Therefore, it can serve as a tool to assess the maturity of such infants. In contrast, AEP was normal in 76% of the cases. The neonatal EEG findings were significantly correlated with the clinical outcome and can be an additional prognostic indicator in congenital hydrocephalus.