Abstracts

Rationale: There is a high incidence of mortality and morbidity associated with neonatal seizures (NS). EEG plays an integral part in accurately diagnosing NS and the background helps prognostication. The characteristics of the ictal EEG may also contribute to prediction of outcomes, understanding of pathogenesis and tailoring of investigations. Methods: We analysed the ictal EEG in 160 NS in 43 babies, captured during a standard VEEG recording and correlated it with outcomes. Results: Of the 160 NS, 61 had clinical correlates (electroclincal szs:ECSz) and 99 were electrographic only (ESz). Overall 40% of NS arose from sleep, 31 from wakefullness and 28 were undetermined; ECSz occurred more frequently from wakefullness. The highest frequency and maximum amplitude of the ictal EEG was significantly higher (p=.0075 and .00001) during the ECSz compared to ESz, with no difference in onset frequency, or mean duration of NS. Table 1 shows NS onset from different areas: temporal being most frequent with frontal and paracentral following. As shown in Table 2, ESz tended to remain focal, regional and hemispheric more frequently than ECSz Mortality was 1/11 with babies with ECSz only, 2/13 in those with both and 6/19 in those with ESZ only. Babies with ECSz had better background EEG and outcomes than those with ESz. Conclusions: Conclusions: Ictal EEGs in ECSz have a higher maximum frequency and amplitude and tend to spread to a larger area of the brain than in ESz. Babies with electroclinical dissociation have poorer background EEG scores, more frequent neurodevelopmental sequelae and higher mortality. NS start most frequently in the temporal, followed by the frontal and paracentral regions. This suggests we may need to reconsider ideal montages for amplitude intergrated EEG. References: Nagarajan L et al. Neurodevelopmental Outcomes in Neonates With Seizures: A Numerical Score of Background Encephalography to Help Prognosticate. J Child Neurol. 2010: doi 10.1177/0883073809355825 Pisani F. et al. Neonatal Seizures: Relation of Ictal Vide-Electroencephalography (EEG) findings with Neurodevelopmental Outcome. J Child Neurol. 2008:23:394-398.