Adequacy of routine EEG examinations in neonates with clinically suspected seizures

This study identified the clinical and electroencephalographic (EEG) characteristics that distinguished neonates with EEG-confirmed 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.