Sequential changes in electroencephalogram continuity in very premature infants

doi:10.1016/0013-4694(92)90167-G

Electroencephalography and Clinical Neurophysiology

Volume 82, Issue 3, March 1992, Pages 197-202

https://doi.org/10.1016/0013-4694(92)90167-G Get rights and content

Abstract

This study was conducted to quantify sequential changes in electroencephalogram (EEG) continuity for 24 h in very premature infants. For a total of 122 days, continuous 2-channel EEG recording was conducted for 28 premature infants from 26 to 33 weeks of conceptional age (CA). None of the infants showed evidence of neurological impairment during hospitalization. Normal neurological outcome was noted at a minimum 12 months of age. By classifying each 5.5 min epoch according to EEG continuity, the number of contiguous epochs of each series of discontinuous type (DTs) and the number of epochs between two series of discontinous type (IDTIs) were counted at each CA. The duration of DT decreased with increasing CA. The mean duration remained at 13–16 min after 29 weeks CA. The mean duration of each IDTI increased with CA, up to about 1 h at 33 weeks. A constant period of DTs was noted at longer intervals with increasing CA. These changes appear related to the development of sleep state organization with CA.

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Cited by (23)

Normal EEG during the neonatal period: maturational aspects from premature to full-term newborns
2021, Neurophysiologie Clinique
Citation Excerpt :
The length of QPs tends to decrease with the establishment of functional interactions within cortical neuronal networks. EEG activity becomes more continuous, leading to a ‘tracé alternant’ at term [3,19,24,26,28,38,48,66]. In parallel, the length of periods of spontaneous activity (APs) increases [48].
Electroencephalography (EEG) is the reference tool for the analysis of brain function, reflecting normal and pathological neuronal network activity. During the neonatal period, EEG patterns evolve weekly, according to gestational age. The first analytical criteria for the various maturational stages and standardized neonatal EEG terminology were published by a group of French neurophysiologists training in Paris (France) in 1999. These criteria, defined from analog EEG, were completed in 2010 with digital EEG analysis. Since then, this work has continued, aided by the technical progress in EEG acquisition, the improvement of knowledge on the maturating processes of neuronal networks, and the evolution of critical care. In this review, we present an exhaustive and didactic overview of EEG characteristics from extremely premature to full-term infants. This update is based on the scientific literature, enhanced by the study of normal EEGs of extremely premature infants by our group of neurophysiologists. For educational purposes, particular attention has been paid to illustrations using new digital tools.
Specialized Neurological Studies
2018, Volpe's Neurology of the Newborn
A variety of specialized studies are available for evaluating the nervous system of the newborn. In this chapter, we review several commonly used tests: cerebrospinal fluid examination, evoked responses (with emphasis on auditory evoked responses), electroencephalography (EEG), cranial ultrasound, and magnetic resonance imaging (MRI). We also touch on some tests that are not yet in common clinical use: near-infrared spectroscopy and magnetoencephalography. The discussion of EEG includes a description of the changes in EEG associated with early brain development and a brief review of amplitude-integrated EEG. The discussion of MRI covers conventional structural imaging (including diffusion imaging) as well as spectroscopy and functional imaging. Overall, we focus on the adaptations necessary to optimize these tests for infants. We also describe the characteristics and nuances relevant to their effective clinical use. The application of most of these tests for diagnostic purposes is mentioned in various other chapters of this book.
Probability distributions of the electroencephalogram envelope of preterm infants
2015, Clinical Neurophysiology
To determine the stationary characteristics of electroencephalogram (EEG) envelopes for prematurely born (preterm) infants and investigate the intrinsic characteristics of early brain development in preterm infants.
Twenty neurologically normal sets of EEGs recorded in infants with a post-conceptional age (PCA) range of 26–44 weeks (mean 37.5 $\pm$ 5.0 weeks) were analyzed. Hilbert transform was applied to extract the envelope. We determined the suitable probability distribution of the envelope and performed a statistical analysis.
It was found that (i) the probability distributions for preterm EEG envelopes were best fitted by lognormal distributions at 38 weeks PCA or less, and by gamma distributions at 44 weeks PCA; (ii) the scale parameter of the lognormal distribution had positive correlations with PCA as well as a strong negative correlation with the percentage of low-voltage activity; (iii) the shape parameter of the lognormal distribution had significant positive correlations with PCA; (iv) the statistics of mode showed significant linear relationships with PCA, and, therefore, it was considered a useful index in PCA prediction.
These statistics, including the scale parameter of the lognormal distribution and the skewness and mode derived from a suitable probability distribution, may be good indexes for estimating stationary nature in developing brain activity in preterm infants.
The stationary characteristics, such as discontinuity, asymmetry, and unimodality, of preterm EEGs are well indicated by the statistics estimated from the probability distribution of the preterm EEG envelopes.
Peak-to-peak amplitude in neonatal brain monitoring of premature infants
2012, Clinical Neurophysiology
To assess the strength of association between alternative measures of electroencephalographic (EEG) signal peak-to-peak amplitude (ppA) and postmenstrual age (PMA) among a cohort of extremely premature infants.
177 Two-channel EEG recordings 3–6 h long were collected from 26 infants born before 29 weeks of gestation. The raw EEG was converted into four different continuous measures of ppA: amplitude-integrated EEG (aEEG), range-EEG (rEEG), Gotman and Gloor’s half-wave decomposition (HWD), and root of mean squares (RMS). For each ppA-measure EEG indices including mean, median, and 5% margins; indices of spread (width, standard deviation, coefficient of variation), and asymmetry were calculated for each 1 min epoch. The medians of each index for the entire recording were tested for association with PMA using linear mixed models.
The log-transformed values of aEEG and rEEG indices of spread were highly associated with PMA (fixed effects $R_{β}^{2}$ = 0.84–0.89).
Indices of spread by aEEG or rEEG can be used as indicators of neonatal brain maturation. However, rEEG produces the absolute values that most closely approximate the raw EEG amplitudes.
The indices of spread and rEEG as a measure of ppA provide a basis for improvements in neonatal EEG monitoring.
Quantitative analysis of maturational changes in EEG background activity in very preterm infants with a normal neurodevelopment at 1year of age
2010, Early Human Development
The electroencephalographic (EEG) background pattern of preterm infants changes with postmenstrual age (PMA) from discontinuous activity to continuous activity. However, changes in discontinuity have been investigated by visual analysis only.
To investigate the maturational changes in EEG discontinuity in healthy preterm infants using an automated EEG detection algorithm.
Weekly 4 h EEG recordings were performed in preterm infants with a gestational age (GA) < 32 weeks and normal neurological follow-up at 1 year. The channel C3–C4 was analyzed using an algorithm which automatically detects periods of EEG inactivity (interburst intervals). The interburst–burst ratio (IBR, percentage of EEG inactivity during a moving time window of 600 s) and mean length of the interburst intervals were calculated. Using the IBR, discontinuous background activity (periods with high IBR) and continuous background activity (periods with low IBR) were automatically detected and their mean length during each recording was calculated. Data were analyzed with regression and multivariate analysis.
79 recordings were performed in 18 infants. All recordings showed a cyclical pattern in EEG discontinuity. With advancing PMA, IBR (R² = 0.64; p < 0.001), interburst interval length (R² = 0.43; p < 0.001) and length of discontinuous activity (R² = 0.38; p < 0.001) decreased, while continuous activity increased (R² = 0.50; p < 0.001). Multivariate analysis showed that all EEG discontinuity parameters were equally influenced by GA and postnatal age.
Analyzing EEG background activity in preterm infants is feasible with an automated algorithm and shows maturational changes of several EEG derived parameters. The cyclical pattern in IBR suggests brain organisation in preterm infant.
Quantitative electroencephalographic patterns in normal preterm infants over the first week after birth
2006, Early Human Development
Currently available tools to assist clinicians with prediction of neurodevelopmental outcome of preterm infants are inadequate. Modified cotside electroencephalography (EEG) has the ability to produce quantitative electrophysiologic measures. These measures may be useful in future prediction of outcome.
To determine patterns of change in quantitative EEG measures in preterm infants during their first week after birth.
Observational.
Preterm infants born at less than 32 weeks completed gestation surviving to discharge with unremarkable serial ultrasound scans.
Changes in continuity, amplitude and spectral edge frequency measures of EEGs obtained over the first week after birth.
Results of EEGs performed using a novel EEG device on 63 infants are reported here. Their median (range) gestation was 29 (24–31) weeks and birthweight was 1235 (540–1980) g. Quantitative measures of EEG continuity increased over the first week after birth from 72 (25–99)% to 92 (54–100)% at the 25 μV threshold, and from 39 (10–87)% to 64 (34–75)% at the 50 μV threshold, both p < 0.0001. There was a related 32% increase in median amplitude from 5.8 (2.6–10.6) μV on day 1 to 7.6 (4.3–9.4) μV on day 4, p = 0.005. There was a trend for average spectral edge frequency to fall from 10.7 (9.3–12.9) Hz on day 1 to 9.9 (8.1–12.3) Hz on day 3, p = 0.06. Each gestational tertile showed similar patterns.
There are consistent changes in quantitative neurophysiologic measures over the first week after birth, and particularly measures of continuity over the first 4 days, in normal preterm infants.

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Main articleSequential changes in electroencephalogram continuity in very premature infants

Abstract

Electroenceph. clin. Neurophysiol.

Electroenceph. clin. Neurophysiol.

Electroenceph. clin. Neurophysiol.

Logit models for an ordinal response

Continuous 4-channel EEG monitoring: a guide to interpretation, with normal values, in preterm infants

Neuropediatrics

Continuous four-channel EEG monitoring in the evaluation of echodense ultrasound lesions and cystic leucomalacia

Arch. Dis. Child.

Predictive value of early continuous electroencephalogram monitoring in ventilated preterm infants with intraventricular hemorrhage

Pediatrics

Neonatal electroencephalograhy

Quantification of changes in normal neonatal EEGs with gestation from continuous five-day recordings

Dev. Med. Child Neurol.

Main article
Sequential changes in electroencephalogram continuity in very premature infants