8 - Is Brain State of the Newborn (BSN) able to distinguish level of encephalopathy in newborns with HIE?

Publication Number: 1007.8

Gabriel F T. Variane, Irmandade da Santa Casa de Misericórdia de São Paulo, São Paulo, Sao Paulo, Brazil; Lena Hellstrom Westas, Department of Women’s and Children’s Health: Uppsala University, Sweden, Lund, Skane Lan, Sweden; Valerie Y.. Chock, Stanford University School of Medicine, Palo Alto, CA, United States; Danieli Mayumi Kimura Leandro, Protecting Brains & Saving Futures, São Paulo, Sao Paulo, Brazil; Silvia Schoenau de Azevedo, Protecting Brains and Saving Futures, São Paulo, Sao Paulo, Brazil; Lina Chalak, Childrens Health Dallas UT Southwestern, DALLAS, TX, United States; Saeed Montazeri, University of Helsinki, Espoo, Uusimaa, Finland; Paula Girotto Fonseca, Protecting Brains and Saving Futures, Sao Paulo, Sao Paulo, Brazil; Sampsa Vanhatalo, Children's Hospital, Helsinki, Uusimaa, Finland; Krisa P. Van Meurs, Stanford University School of Medicine, Palo Algo, CA, United States

Background: Brain state of the newborn (BSN) is a new automated method to quantitatively measure EEG background activity. BSN can be continuously displayed as a trend with values ranging from zero (inactive) to 100 (fully continuous). BSN trends during the first 48 hours of life have been shown to differ between infants with mild, moderate and severe HIE and to be predictive of outcome.

Objective: To assess the association between BSN levels and the severity of encephalopathy as determined by the modified Sarnat exam performed at < 6 hours of age.

Design/Methods: Newborns with hypoxic-ischemic encephalopathy (HIE) monitored with reduced channel aEEG (C3-P3, C4-P4, P3-P4) in 30 Brazilian hospitals between May and September 2025 were included. Clinical data, including modified Sarnat exam, were collected. Background pattern was assessed visually during the first 24 hours in 6-hour epochs. For the BSN analyses, the raw EEG data was exported to a secure Babacloud platform that provides fully automated minute wise computation of BSN values, including rejection of periods with artifact and seizure activity. Individual infant BSN trends using 1-hourly median BSN values were computed and grouped by encephalopathy grade, showing group median values and interquartile ranges (IQR 25-75).

Results: A total of 72 newborns were included: 28 (39%) with mild, 28 (39%) with moderate, and 16 (22%) with severe HIE. Detailed demographic and clinical characteristics are shown in Table 1. All infants with moderate or severe HIE received therapeutic hypothermia (TH) and selected infants with mild HIE received TH. The aEEG/EEG monitoring commenced at a mean chronological age of 3 hours 43 minutes (±1hours 29 minutes) and the mean recording time was 77 hours 03 minutes (±58 hours 09 minutes) with range from approximately 12 to 266 hours. BSN values differed between HIE groups, with typical median BSN levels during the first 12 hours exceeding 77 in mild and moderate HIE, and were generally below 40 in severe HIE during the first 24 hours of life. Figure 1 shows the BSN temporal trajectories, illustrating the evolution of BSN values and their progressive recovery during the cooling and rewarming periods. Seizures were detected in 2 (7.1%) infants with mild HIE, 7 (25.0%) with moderate HIE, and 6 (37.5%) with severe HIE (Table 2).

Conclusion(s): BSN values were associated with the clinical severity of HIE, supporting its potential as an automated quantitative biomarker of neonatal brain function.

Table 1 - Demographic Variables and in-hospital outcomes.
aPerinatal event was defined as: Late decelerations (Type II DIP), umbilical cord prolapse or rupture, uterine rupture, third-trimester hemorrhage, maternal cardiopulmonary arrest, other situations of acute fetal distress.
ASM: antiseizure medication.

Table 2 - Video aEEG/EEG findings.


Figure 1. BSN temporal trajectories