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Background: Perinatal asphyxia often leads to hypoxic-ischemic encephalopathy (HIE) with a high risk of neurodevelopmental consequences. While moderate and severe HIE link to high morbidity, less is known about brain effects of perinatal asphyxia with no or only mild HIE. Here, we test the hypothesis that cortical activity networks in the newborn infants show a dose-response to asphyxia., Methods: We performed EEG recordings for infants with perinatal asphyxia/HIE of varying severity (n = 52) and controls (n = 53) and examined well-established computational metrics of cortical network activity., Results: We found graded alterations in cortical activity networks according to severity of asphyxia/HIE. Furthermore, our findings correlated with early clinical recovery measured by the time to attain full oral feeding., Conclusion: We show that both local and large-scale correlated cortical activity are affected by increasing severity of HIE after perinatal asphyxia, suggesting that HIE and perinatal asphyxia are better represented as a continuum rather than the currently used discreet categories. These findings imply that automated computational measures of cortical function may be useful in characterizing the dose effects of adversity in the neonatal brain; such metrics hold promise for benchmarking clinical trials via patient stratification or as early outcome measures., Impact: Perinatal asphyxia causes every fourth neonatal death worldwide and provides a diagnostic and prognostic challenge for the clinician. We report that infants with perinatal asphyxia show specific graded responses in cortical networks according to severity of asphyxia and ensuing hypoxic-ischaemic encephalopathy. Early EEG recording and automated computational measures of brain function have potential to help in clinical evaluation of infants with perinatal asphyxia., (© 2023. The Author(s).)

Objective: To assess whether computational electroencephalogram (EEG) measures during the first day of life correlate to clinical outcomes in infants with perinatal asphyxia with or without hypoxic-ischemic encephalopathy (HIE)., Methods: We analyzed four-channel EEG monitoring data from 91 newborn infants after perinatal asphyxia. Altogether 42 automatically computed amplitude- and synchrony-related EEG features were extracted as 2-hourly average at very early (6 h) and early (24 h) postnatal age; they were correlated to the severity of HIE in all infants, and to four clinical outcomes available in a subcohort of 40 newborns: time to full oral feeding (nasogastric tube NGT), neonatal brain MRI, Hammersmith Infant Neurological Examination (HINE) at three months, and Griffiths Scales at two years., Results: At 6 h, altogether 14 (33%) EEG features correlated significantly to the HIE grade ([r]= 0.39-0.61, p < 0.05), and one feature correlated to NGT ([r]= 0.50). At 24 h, altogether 13 (31%) EEG features correlated significantly to the HIE grade ([r]= 0.39-0.56), six features correlated to NGT ([r]= 0.36-0.49) and HINE ([r]= 0.39-0.61), while no features correlated to MRI or Griffiths Scales., Conclusions: Our results show that the automatically computed measures of early cortical activity may provide outcome biomarkers for clinical and research purposes., Impact: The early EEG background and its recovery after perinatal asphyxia reflect initial severity of encephalopathy and its clinical recovery, respectively. Computational EEG features from the early hours of life show robust correlations to HIE grades and to early clinical outcomes. Computational EEG features may have potential to be used as cortical activity biomarkers in early hours after perinatal asphyxia., (© 2024. The Author(s).)

Background: Extremely low gestational age newborns (ELGANs) are at risk of neurodevelopmental impairments that may originate in early NICU care. We hypothesized that early oxygen saturations (SpO 2 ), arterial pO 2 levels, and supplemental oxygen (FiO 2 ) would associate with later neuroanatomic changes., Methods: SpO 2 , arterial blood gases, and FiO 2 from 73 ELGANs (GA 26.4 ± 1.2; BW 867 ± 179 g) during the first 3 postnatal days were correlated with later white matter injury (WM, MRI, n = 69), secondary cortical somatosensory processing in magnetoencephalography (MEG-SII, n = 39), Hempel neurological examination (n = 66), and developmental quotients of Griffiths Mental Developmental Scales (GMDS, n = 58)., Results: The ELGANs with later WM abnormalities exhibited lower SpO 2 and pO 2 levels, and higher FiO 2 need during the first 3 days than those with normal WM. They also had higher pCO 2 values. The infants with abnormal MEG-SII showed opposite findings, i.e., displayed higher SpO 2 and pO 2 levels and lower FiO 2 need, than those with better outcomes. Severe WM changes and abnormal MEG-SII were correlated with adverse neurodevelopment., Conclusions: Low oxygen levels and high FiO 2 need during the NICU care associate with WM abnormalities, whereas higher oxygen levels correlate with abnormal MEG-SII. The results may indicate certain brain structures being more vulnerable to hypoxia and others to hyperoxia, thus emphasizing the role of strict saturation targets., Impact: This study indicates that both abnormally low and high oxygen levels during early NICU care are harmful for later neurodevelopmental outcomes in preterm neonates. Specific brain structures seem to be vulnerable to low and others to high oxygen levels. The findings may have clinical implications as oxygen is one of the most common therapies given in NICUs. The results emphasize the role of strict saturation targets during the early postnatal period in preterm infants., (© 2021. The Author(s).)

Background: Higher cortical function during sensory processing can be examined by recording specific somatosensory-evoked magnetic fields (SEFs) with magnetoencephalography (MEG). We evaluated whether, in extremely low-gestational-age (ELGA) infants, abnormalities in MEG-recorded SEFs at term age are associated with adverse neurodevelopment at 2 y of corrected age., Methods: SEFs to tactile stimulation of the index finger were recorded at term age in 30 ELGA infants (26.5 ± 1.2 wk, birth weight: 884 g ± 181 g). Neurodevelopment was evaluated at 2 y of corrected age. Controls were 11 healthy term infants., Results: In nine of the ELGA infants (30.0%), SEFs were categorized as abnormal on the basis of lack of response from secondary somatosensory cortex (SII). At 2 y, these infants had a significantly worse mean developmental quotient and locomotor subscale on the Griffiths Mental Development Scales than the ELGA infants with normal responses. Mild white matter abnormalities in magnetic resonance imaging at term age were detected in 21% of infants, but these abnormalities were not associated with adverse neurodevelopment., Conclusion: Abnormal SII responses at term predict adverse neuromotor development at 2 y of corrected age. This adverse development may not be foreseen with conventional neuroimaging methods, suggesting a role for evaluating SII responses in the developmental risk assessment of ELGA infants.

This study was set out to develop and describe a novel, simple, and safe method for routine bedside testing of somatosensory system in very early preterm infants. We recorded electroencephalogram (EEG) activity after tactile stimulation of hand (palm) and foot (sole) by a soft hairbrush stimulator in extremely low birth weight infants (n = 10; GA, 24-28, recording at conceptional age 30-32 wk) and compared with the raw EEG responses to those seen by one- or two-channel brain monitors. In every subject, single tactile stimuli produced prominent (100-350 microV) somatosensory evoked responses (SERs) that were readily identified in the ongoing EEG signal. The maximal SER was in the contralateral hemisphere at around the corresponding somatosensory representation areas. Conventional EEG filtering did significantly reduce the SERs, but they could still be identified in the routine brain monitor setting widely available in NICUs. The method described here is directly applicable to assessment of integrity of somatosensory system in the early preterm period. It needs minimal training and requires an EEG system or a brain monitor device that is available in most units. Thus, the technique is likely to open a novel window to neurologic assessment of these babies.