P051 Auditory event related potentials in preterm infants recorded in quiet and active sleep

Abstract

Biostatistical Unit, Department of Neuroscience, University ofPadua, Padua ItalyObjective: To investigate the influence of active and quietsleep on auditory event related potentials recorded inpreterm infants.Methods: Eighteen preterm newborns underwent auditoryevent related potentials during quiet and active sleep, beforedischarge from neonatal intensive care unit. An auditoryoddball paradigm was used with frequently occurring‘standard’ tones at 1000 Hz and rarely occurring ‘deviant’tones at 2000Hz.The waveforms recorded at Fz,Cz,Pz,T3 andT4 locations were divided into twenty 50ms. intervals andabsolute mean amplitude within each interval was calculatedfor statistical analysis.Results: In active sleep, at Fz location, the responses tostandard and deviant stimuli were significantly different(p=0.005), the difference involved the time period from200 to 300 ms. after stimulus (time bins 7th p=0.006 and8th p<0.001); in quiet sleep no significant difference wasfound (p=0.32). In addition, in the difference waveform(deviant minus standard) a significant effect was found forelectrode placement (p=0.003), for Fz electrode location bysleep condition (p=0.038) and for sleep condition by time bin(p=0.028).Conclusions: Responses to standard tones were recorded inactive as well as quiet sleep. With the paradigm adopted inthe present study mismatch responses to deviant tones seemreliably recorded only in active sleep.Significance: In view of a possible clinical role of auditoryevent related potentials in preterm infants, our data suggestto perform recordings in active sleep.P052 Hashimoto encephalopathy in Down’s syndrome withdimethylargininase-1 autoantibodiesH. Verhelst, P. Verloo, B. De Paepe, B. Gini, B. Bonetti, R. VanCoster.