Abstract: Background：Periodic discharges (PDs）have attracted more and more attention in electroencephalogram (EEG) monitoring of adult and pediatric critical patients, and the correlation between PDs and seizures is very high. But so far, there are very few reports on PDs in newborns. Neonatal PD is still an EEG phenomenon with unknown clinical significance. Objective：To investigate the incidence and etiological characteristics of PDs in neonates, and the correlation with seizures and brain injury. Design：Case series report. Methods：The data of neonatal cases monitored by video electroencephalogram (vEEG) in Shengjing Hospital Affiliated to China Medical University from January 2018 to December 2022 were collected. Newborns with seizures and PDs were searched in the EEG database, and their EEG data and head magnetic resonance imaging (MRI) results were reinterpreted, and the clinical data were analyzed and summarized. Main outcome measures：Incidence of PDs in neonates. Results：Out of 4 685 neonates, 167 (3.6%) developed PDs. The primary causes of PDs for full-term infants were hypoxic-ischemic encephalopathy, white matter injury, and intracranial infection, while for preterm infants the primary causes are cerebral hemorrhage, white matter injury, and hypoxic-ischemic encephalopathy. Electrical or electro-clinical seizures were detected in 93.4% of the neonates, 54.5% had multiple or frequent seizures, and 37.1% had status epilepticus. Sixty-eight cases (40.7%) had recurrent single foci in a certain brain region, 47 cases (28.1%) had multifocal asynchrony, 29 cases (17.4%) had simultaneous appearance in one hemisphere, and 23 cases (13.8%) had simultaneous appearance in both hemispheres. Of the 115 cases with single-focal recurrence and multi-focal asynchrony, 89 cases (77.4%) involved the central and/or midline regions and the temporal region. Among the causes of PDs, statistical significance was found between different PD sites and PD causes of hypoxic ischemic encephalopathy, arterial ischemic stroke, intracranial hemorrhage, intracranial infection, white matter injury, and unexplained convulsion. There were 129 cases (77.2%) with PDs in different parts of brain injury. There was statistical significance between different PD distribution sites and focal or multifocal micro-white matter injury, large area injury in one hemisphere，and extensive whole brain. Among the 132 children who completed at least two monitoring, 43.9% of PDs gradually disappeared 1-7 days after onset, 28.0% disappeared at 8-14 days after onset, and 12.1% disappeared at 15-32 days after onset. Besides, 15.9% of the neonates with persistent PDs had congenital brain structural abnormalities and genetic abnormalities. Conclusions：The incidence of PDs in neonates is low, and there are many potential causes. It is closely related to seizures. PDs are associated with structural brain injury or dysfunction. PDs can be regarded as one of the characteristic EEG changes in the acute phase of neonatal brain injury.

Key words: Periodic discharge, Neonate, Video EEG, Brain injury, Seizures