Adequacy of Routine EEG Examinations in Neonates With Clinically Suspected Seizures

Abstract

This study identified the clinical and electroencephalographic (EEG) characteristics that distinguished neonates with EEGconfirmed seizures from those without, in order to assess the adequacy of routine short-term EEG examinations in neonates with clinically suspected seizures. Two different subgroups of tracings were analyzed: EEGs performed on therapeutically paralyzed (TP+) neonates and EEGs performed on non-therapeutically paralyzed (TP-) neonates. The rate of electrographic seizures, abnormal EEG background activity, and excessive sharp EEG transients (SETs) was significantly more common in the tracings performed on TP- neonates. In lethargic/comatose TP- neonates with clinically suspected seizures and abnormal EEG background activity, the rate of EEGs with excessive SETs (implying a "lowered seizure threshold") occurred equally in tracings with or without documented electrographic seizures. Consequently, we suspect that routine EEGs may be inadequate to electrographically confirm suspected seizures in some TP- neonates due to a large sampling error. In contrast, routine 40-minute EEGs are probably adequate to seek evidence of electrographic seizure activity in TP+ neonates because their seizure rate is low and most do not display background abnormalities or excessive SETs. (J Child Neurol 1992;7:215-220).