PRETERM MATURATION OF THE SOMATOSENSORY-EVOKED POTENTIAL

This study investigated the maturational patterns of the cortical soma tosensory evoked potential (SEP) in the preterm period. SEPs were reco rded in 22 preterm neonates (27-32 weeks gestational age (g.a.), mean age 28.4 weeks g.a.; total of 46 studies). The infants were first test ed at an average of 5 days. At birth, all of the infants had normal ne urological examinations and normal cranial ultrasounds. On follow-up t he infants were assessed regularly by a multidisciplinary team and all those included in this series, al follow-up periods of 6-25 months co rrected age (mean 14.8 months), had normal neuro-developmental examina tions. SEPs were recorded in all of the infants. The waveform consiste d of triphasic positive, negative and positive components (at 75 ms, 1 25 ms and 178 ms, respectively at 27 weeks g.a.). Latencies of these c omponents decreased rapidly over the preterm period, such that by 32 w eeks g.a. they were at 41, 72 and 112 ms, respectively. There appeared to be no differences in the maturational changes as a function of ges tational age at birth.