Changes of amplitude integration electroencephalogram (aEEG) in different maturity preterm infant

The effects of betamethasone on the amplitude integrated EEG of infants born at 34- or 35-weeks gestation

OBJECTIVE

Assess if maternal betamethasone administration at 34-35 weeks accelerated neonatal amplitude integrated EEG (aEEG) maturation.

STUDY DESIGN

Nested, observational cohort in 7 centers participating in the Antenatal Late Preterm Steroid randomized trial. Up to 2 aEEGs were obtained in neonates born from 34⁰-35⁶ weeks gestation before 72 h (aEEG 1) and at 5-7 days (aEEG 2) if hospitalized. Personnel and aEEG central readers were masked to the intervention. The primary outcome was maturation reflected by cycle frequency; secondary outcomes were border voltage, span, and discontinuity.

RESULTS

58 neonates were enrolled (betamethasone, 28, placebo, 30). On aEEG 1, cycle frequency did not differ, but betamethasone exposed infants had a greater lower border voltage and a broader span. On aEEG 2, both groups displayed increases in lower border voltage.

CONCLUSIONS

Betamethasone associated changes in lower border voltage support accelerated electrical activity. Further investigation is needed to understand the broader span.

The effect of kangaroo mother care on aEEG activity and neurobehavior in preterm infants: a randomized controlled trial

OBJECTIVE

To evaluate the effect of kangaroo mother care (KMC) versus traditional care (TC) on aEEG activity and neurobehavior in preterm infants.

METHODS

A prospective randomized control single-blinded trial conducted in a tertiary level neonatal intensive care unit between October 2019 and October 2020. Preterm infants with gestational age of 31-33 weeks were randomly divided into either a KMC group or a TC group. Outcomes were compared between the groups including aEEG scores, the percentage of mature sleep-wake cycling (SWC) and background activity continuity, narrowband upper and lower bound amplitude, narrowband bandwidth, and neonatal behavioral neurological assessment (NBNA) scores on day 1, day 7, and day 14 after randomization.

RESULTS

A total of 65 infants (32 in KMC group and 33 in TC group) completed protocol. No significant differences were observed in outcomes on day 1. aEEG scores (p = .027 and p = .007, respectively) and the percentage of mature SWC (p = .034 and p = .039, respectively) were significantly higher in KMC group on day 7 and day 14. Compared to the TC group, KMC group had a narrower bandwidth on day 7 (p = .003) and day 14 (p = .016) and higher lower bound amplitude on day 14 (p = .002). Upper bound amplitude and the percentage of continuity were comparable between the groups on day 7 and day 14. The NBNA scores in the KMC group were significantly higher than that of the TC group on day 7 (p < .001) and day 14 (p < .001).

CONCLUSIONS

Preterm infants submitted to the KMC, compared to those non-submitted, have more mature aEEG activity and better neurobehavior performance on day 7 and day 14 after random.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR1900026363.

The value of cardiorespiratory parameters for sleep state classification in preterm infants: A systematic review

Cardiorespiratory activity is highly associated with infants' sleep duration and quality. We performed a systematic literature search of PubMed and EMBASE databases to investigate if and how cardiorespiratory parameters can be used for sleep state classification in preterm infants and in what way maturation influences this relation. All retrieved citations were screened against predetermined inclusion and exclusion criteria. Only studies of preterm infants (<37 wk postmenstrual age during sleep state classification) admitted to a neonatal ward and of whom at least one sleep state and one cardiorespiratory parameter was measured, were included. Two researchers independently reviewed the included studies on methodological quality. Of the 1097 initially retrieved studies, 23 were included for analysis. Heart rate and respiration frequency are strongly correlated with active sleep and quiet sleep. In quiet sleep, as compared to active sleep, respiratory frequency is more stable, and the heart rate is lower and less variable. This association, however, differed across preterm birth subtypes (i.e., extremely, very or late preterm), indicating that maturation - in the form of both gestational and postnatal age - influences the cardiorespiratory characteristics of preterm sleep states. The knowledge gained from this review can help improve behavioral sleep classification and automated sleep classification algorithms for preterm infants.

Influence of Intensive Care Unit Enlightenment on Premature Infants on Functional Brain Maturation Assessed by Amplitude-Integrated Electroencephalograph

OBJECTIVE

Amplitude-integrated electroencephalograph (aEEG) presents a valuable tool for functional brain maturation of preterm infants. However, the effect of enlightenment on functional brain maturation of premature infants has not been investigated. We aimed to do this with aEEG.

STUDY DESIGN

A total of 32 infants, 30 to 35 gestational weeks, were involved in the study. They were randomly distributed into three groups in which different lighting protocols were applied. In group 1, the infants' incubators were covered for 24 hours. In group 2, the infants' incubators were open for 24 hours. In group 3, the infants' incubators were covered for 12 hours and open for another 12 hours. The infants are evaluated with aEEG recordings done on the 3rd (first measurement) and 10th days (second measurement) along with the Burdjalov scoring. Analysis of aEEG recordings was performed, based on sleep-wake cycles (SWCs), upper and lower margin amplitudes, narrowband and broadband of SWC, and bandwidth of SWC.

RESULTS

At first, the narrowband lower amplitudes in group 1 were higher than those of the other groups (p = 0.042), but the difference was not significant in the second measurement (p = 0.110). The Burdjalov scores were higher in group 1 and group 3 on 10th day, though not statistically significant (p = 0.871). When the infants were re-evaluated according to the gestational weeks, the Burdjalov scores of the two groups less than 34 weeks (30-31 and 32-33 weeks) were similar, whereas 34 to 35 weeks were higher when compared with those of the two groups.

CONCLUSION

The difference observed between groups in terms of narrowband lower amplitude in the first measurement may reflect the effect of intrauterine environment rather than enlightenment at the same gestational age because it was made on the third day. However, the fact that all groups have similar results on day 10 suggests that other factors in the intensive care setting may diminish the effect of enlightenment. Burdjalov scores are associated with maturation, and high scores found in the 34- to 35-week group suggest that the 34-week maturation might be a threshold for SWC and development in our group sample.

Structural brain maturation differs between preterm and term piglets, whereas brain activity does not

AIM

The aim of the study was to investigate whether amplitude-integrated electroencephalography (aEEG) and cerebral magnetic resonance imaging (MRI) in preterm piglets would provide measures of cerebral functional, microstructural and anatomical maturation, which might reflect the signs of functional brain immaturity, documented in preterm piglets.

METHODS

During July-October 2013 at the NEOMUNE Centre, Copenhagen University, Denmark, 31 preterm (90% gestation) and 10 term piglets underwent aEEG on days 1, 2, 4 and 11, and MRI on day 25. Physical activity levels were recorded.

RESULTS

Preterm showed delayed neonatal arousal and physical activity, relative to term piglets. Preterm piglets had lower growth rates and brain volume than term piglets, but aEEG patterns were similar. MRI mean diffusivity was also similar, but fractional anisotropy (FA) was lower in preterm piglets (p < 0.001).

CONCLUSION

Functional brain maturation, as assessed by aEEG, was relatively advanced in preterm piglets. Conversely, the low FA in the preterm piglets suggests that the white matter microstructure remains less mature in preterm compared to term piglets at postnatal day 25. The results might be utilised to define whether and how preterm piglets may contribute to preclinical models for brain development in preterm infants.

Early amplitude-integrated electroencephalography predicts brain injury and neurological outcome in very preterm infants

Early amplitude-integrated electroencephalography (aEEG) has been widely used in term infants with brain injury to predict neurodevelopmental outcomes; however, the prognostic value of early aEEG in preterm infants is unclear. We evaluated how well early aEEG could predict brain damage and long-term neurodevelopmental outcomes in very preterm infants compared with brain imaging assessments. We found that severe aEEG abnormalities (p=0.000) and aEEG total score<5 (p=0.006) within 72 h after birth were positively correlated with white-matter damage, but aEEG abnormalities were not associated with intracranial hemorrhage (p=0.186). Severe abnormalities in aEEG recordings, head ultrasound, and cranial magnetic resonance imaging (MRI) were all positively correlated with poor outcome at 18 months corrected age. The predictive power of poor outcomes of the aEEG and MRI combination was the same as the aEEG, MRI, and head ultrasound combination with a sensitivity of 52.4%, specificity of 96.2%, positive predictive value of 78.6%, and negative predictive value of 88.4%. These results indicate that severely abnormal aEEG recordings within 72 h after birth can predict white-matter damage and long-term poor outcomes in very preterm infants. Thus aEEG can be used as an early marker to monitor very preterm infants.

Effect of caffeine on preterm infants' cerebral cortical activity: an observational study

OBJECTIVE

Our first aim was to investigate the effects of caffeine on preterm infants' respiratory functions and brain cortical activity (conventional and amplitude-integrated electroencephalography (cEEG and aEEG)). Secondary aim was to study its long-term effects on respiratory system and electroencephalographic maturation by 36 weeks post-menstrual age.

METHODS

Prospective observational study on 33 consecutively admitted preterm infants less than 34-weeks-gestation. cEEG and aEEG, cardiopulmonary and sleep state were recorded in 20 preterm infants, before, during and 2-hours after intravenous (IV) caffeine (caffeine Group), and for 13 preterms (control group). Both groups were subjected to assessment of cerebral cortical maturation by cEEG and aEEG at 36-weeks post-menstrual age as an outcome measure.

RESULTS

IV caffeine administration significantly increased heart rate (p = 0.000), mean arterial blood pressure (p = 0.000), capillary oxygen saturation (p = 0.003), arousability (p = 0.000) and aEEG continuity (p = 0.002) after half an hour. No clinical seizures were recorded and non-significant difference was found in electrographic seizures activity in cEEG. At 36-weeks post-conceptional age, NICU stay was significantly longer in controls (p = 0.022). aEEG score was significantly higher in caffeine group than the control group, (p = 0.000).

CONCLUSIONS

Caffeine increases preterm infants' cerebral cortical activity during infusion and results in cerebral cortical maturation at 36weeks, without increase in seizure activity.