Neonatal Neurology: Clinical Research
Neonatal Neurology 4: Clinical 4
Micheline Lagacé, MD, FRCPC (she/her/hers)
Neonatal neurology fellow, Clinician investigator program
University of British Columbia Faculty of Medicine
Toronto, Ontario, Canada
Assessing early brain recovery with EEG supports prognostication after neonatal encephalopathy. Brain State of the Newborn (BSN) is a recently developed automated measure of EEG background activity, which translates EEG into a continuous score from 0 to 100, and can be displayed as a trend on bedside monitors.
Objective:
To assess the capacity of BSN to predict neurodevelopmental outcomes in neonatal encephalopathy.
Design/Methods:
From an out-born center, 100 newborns ≥36 weeks PMA with neonatal encephalopathy were recruited within 6 hours of life and monitored with a long-term EEG for at least 48 hours. The BSN was calculated off-line for every minute of EEG recording, using four EEG channels. The neurodevelopmental evaluation was done at 18 months using the Bayley-III. Poor outcome was defined by death and low composite scores on the Bayley-III, with the conservative threshold being ≤70 and the inclusive threshold being ≤85. Poor overall outcome was defined as death or poor outcome in at least one Bayley-III composite score. Receiver operating characteristic (ROC) and likelihood ratio (LR) curves at specific ages were used to assess the capacity of BSN to predict outcomes.
Results:
The final analyses included 92 infants, 61% males, born at 39.6±1.3 weeks PMA, with umbilical artery pH 7.00±0.17. There were 9 neonatal deaths, and 1 infant died from sudden infant death syndrome after the neonatal period. Poor outcomes were documented in 21 infants (23%) using conservative Bayley-III cut-offs, and in 40 infants (44%) using inclusive cut-offs. Poor outcomes were better predicted using the conservative instead of the inclusive Bayley-III cut-offs, with BSN during the first 24 hours of life best predicting poor outcome at 18 months (AUC=0.84; Figure 1). Using the conservative cut-offs for developmental domains, BSN during the first 24 hours of life best predicted motor (AUC=0.97) and language (AUC=0.82) outcomes, while cognitive outcomes were best predicted by BSN during the first 36 hours of life (AUC=0.90). Temporal evolution of prognostication by BSN is emphasized when using specific BSN thresholds to calculate LRs (Figure 2). Regarding poor motor outcomes with conservative cut-offs, a BSN score of 60 at 24h of life corresponds to a negative LR of 0.08 and a positive LR of 16.16 (Figure 2).
Conclusion(s):
BSN is a promising open-access algorithm for early interpretation of EEG background in patient with neonatal encephalopathy. Compared to amplitude-integrated EEG and EEG, BSN offers a fully automated and quantitative information for early brain monitoring to support prognostication as early as 24h.