The use of evoked potentials in the neonatal intensive care unit.

The data reported in the literature and our own findings have shown, that evoked potentials (EPs) can be performed at the bedside and provide additional information about the integrity of the central nervous system. Auditory brainstem responses (ABRs) are especially useful for early identification of audiological problems and whenever possible, at risk newborn infants (table II) should be screened using either ABRs or other methods like the otoacoustic emission before discharge. ABRs appear to be less useful in predicting neurological impairment, especially in the preterm infant. Visual evoked potentials (VEPs) can easily be performed at the bedside and are of predictive value for both neurological and visual outcome in the fullterm infant with hypoxic ischaemic encephalopathy (HIE) and the preterm infant in whom the cysts extend into the deep white matter. VEPs will help to identify at an early stage those infants who will suffer severe visual impairment being cortically mediated. Somatosensory evoked potentials (SEPs) are the most difficult to perform of the EPs, but adapting filter settings and stimulation rate it is also possible to obtain responses following stimulation of both the median and posterior tibial nerve. Median nerve SEPs are of predictive value in the fullterm infant with HIE with regard to neurodevelopmental outcome. In the preterm infant however, the predictive value is not so good for the median nerve and more data are needed to assess the predictive value of the posterior tibial nerve SEP.