Amplitude-integrated electroencephalography in preterm infants with cystic periventricular leukomalacia

doi:10.1016/j.earlhumdev.2010.12.008

Early Human Development

Volume 87, Issue 3, March 2011, Pages 217-221

https://doi.org/10.1016/j.earlhumdev.2010.12.008 Get rights and content

Abstract

Aim

This study aimed to assess amplitude-integrated electroencephalography (aEEG) findings in preterm infants with cystic periventricular leukomalacia (cPVL) in the early neonatal period.

Methods

We analyzed five infants with cPVL, whose gestational age was between 27 and 30 weeks, and 15 matched control infants. Two-channel (C3–O1 and C4–O2) aEEG was obtained by digital conversion from a conventional electroencephalogram, which was recorded at days 0–5, 6–13, and 21–34 in each infant. We evaluated the averaged two-channel values of several measurements using visual and quantitative analyses.

Results

Infants with cPVL had a significant higher maximal upper-margin amplitude value, with a median of 47.5 μV (range of 42.5–60) compared with the control infants (median, 33.8; range, 23.8–50) in the second visual-analysis record. Infants with cPVL also had a significantly higher mean upper-margin amplitude value, with a median of 18.8 μV (range, 17.7–23.2) compared with the control infants (median, 16.3; range, 10.3–19.0) in the second quantitative-analysis record.

Conclusions

We demonstrated that the upper-margin amplitude of aEEG in infants with cPVL was significantly higher than that in the control infants at 6–13 days after birth.

Introduction

Despite advances in neonatal intensive care, periventricular leukomalacia (PVL) is still one of the most important causes of neurological impairment in preterm infants. Affected infants suffer from various neurological sequelae, including motor and cognitive impairments, visual problems, and epilepsy. We reported previously that a conventional electroencephalogram (EEG) was a powerful tool to assess brain damage, such as PVL, in preterm infants during the early neonatal period [1], [2], [3], [4], [5], [6].

Amplitude-integrated electroencephalography (aEEG) has been widely used as a continuous brain-function monitoring tool in neonatal intensive care units. aEEG examination and interpretation are much easier than those of conventional EEG. aEEG is very useful for predicting neurodevelopmental outcomes in asphyxiated term infants. Although several studies have assessed aEEG findings in preterm infants with intraventricular hemorrhage during the early neonatal period [7], [8], [9], [10], its clinical significance in preterm infants has hardly been determined. In particular, few reports have addressed aEEG findings in preterm infants with PVL during the early neonatal period. We hypothesized that aEEG would reveal differences between infants with cystic PVL and normal infants. The aim of this study was to determine the details of aEEG findings in preterm infants with cystic PVL using visual and quantitative analyses.

Section snippets

Patients

Three hundred thirty preterm infants of less than 34 weeks gestational age were admitted to the neonatal intensive care unit of Okazaki City Hospital between January 1999 and December 2006. We examined cranial ultrasonography in all patients almost every day during the first week of life and at least once weekly thereafter until discharge using a Hewlett-Packard Image Point HX with 7.5 MHz probes (Philips Medical Systems, Andover, MA, USA) and evaluated the findings according to previously

Results

The patients' characteristics are presented in Table 1. The second EEG record was not obtained in one infant with cystic PVL. No statistically significant difference was observed in any item between the two groups except for the third EEG recording on the day after birth. However, the post-conceptional age of the third EEG recording showed no significant difference between groups. No infant had received sedative medications.

Cranial ultrasonography grading during the neonatal period, follow-up

Discussion

Using visual and quantitative analyses, we revealed that the upper-margin amplitudes, and bandwidth spans of the aEEG at 6–13 days after birth were much higher in infants with cystic PVL than in the normal control infants. We thought that the increased upper-margin amplitude of the aEEG in infants with PVL would reflect the disorganized patterns of conventional EEG [3], [4], [6]. In fact, conventional EEG showed moderate to severe disorganized patterns in all infants with PVL at 6–13 days after

Conflict of interest statement

We do not have any financial relationships with pharmaceutical companies, medical equipment manufacturers, biomedical device manufacturers, or any companies with significant involvement in the field of health care. We have no conflict of interest in relation with this manuscript.

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Determination of timing of brain injury in preterm infants with periventricular leukomalacia with serial neonatal electroencephalography
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Prognostic value of EEG depression in preterm infants for later development of cerebral palsy
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Chronologic changes in neonatal EEG findings in periventricular leukomalacia
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Evaluation of the suitability and clinical applicability of different electrodes for aEEG/cEEG monitoring in the extremely premature infant
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La neuromonitorización de la función cerebral mediante electroencefalografía continua (aEEG/cEEG) es una herramienta esencial en el cuidado estándar del niño a término, y de utilidad creciente en el niño prematuro como biomarcador de lesión y maduración cerebral. Sin embargo, la colocación de los electrodos supone un gran reto, especialmente en el niño prematuro extremo, desalentando frecuentemente su neuromonitorización. El objetivo de este estudio es analizar los diferentes electrodos disponibles, seleccionar el que mejor se adapta a las peculiaridades del niño prematuro extremo y evaluar su aplicabilidad en la práctica clínica.
Con motivo del diseño de un protocolo de estudio de neuromonitorización mediante aEEG/cEEG en niños prematuros < 28 semanas, analizamos nuestra experiencia con los tipos de electrodos disponibles y seleccionamos el que consideramos más adecuado para esta población mediante la valoración de: necesidad de preparación del cuero cabelludo, rapidez de colocación, si se trataba de una aplicación invasiva, posibilidad de reposicionamiento, riesgo de lesiones cutáneas, esterilidad de la técnica y durabilidad. El electrodo elegido se utilizó para la monitorización continua electroencefalográfica iniciada en las primeras 24 h de vida y mantenida al menos hasta las 72 h.
Los electrodos evaluados fueron: agujas subdérmicas, cucharillas de plata y 2 tipos de electrodos autoadhesivos (de hidrogel sólido y de gel conductor líquido). Los electrodos de gel conductor líquido fueron los elegidos. Se utilizaron en 41 neonatos con una edad gestacional media de 25,8 ± 1,1 semanas. Se obtuvo una buena impedancia duradera de forma rápida y sin necesidad de manipulaciones excesivas y no observamos lesiones cutáneas. La satisfacción del personal involucrado en su colocación fue muy elevada.
Los electrodos autoadhesivos desechables con gel conductor líquido y cable integrado permiten una colocación rápida y no invasiva para una monitorización aEEG/cEEG prolongada y de buena calidad en el niño prematuro extremo.
Monitoring of brain function using continuous electroencephalography (aEEG/cEEG) is an essential tool in the standard care of the term infant, and its use is growing in the premature infant as a biomarker of lesion and brain maturity. However, the placing of the electrodes is a great challenge, particularly in the extremely premature infant, which often discourages neuromonitoring. The aim of this study is to assess the different electrodes available, to select the one that best suits the peculiarities of the extremely premature infant, and evaluate its applicability in clinical practice.
With the aim of designing a neuromonitoring study protocol using aEEG/cEEG in < 28 weeks premature infants, an analysis was made of our experience with the type of electrodes available. The electrode that was considered most suitable for this population was chosen by assessing: the need of preparing the scalp, speed in positioning the electrodes, if the application was invasive or not, the possibility of repositioning, risk of skin injuries, sterility of the technique, and durability. The electrode chosen was used for continuous electroencephalographic monitoring started in the first 24 h of life, and maintained until at least 72 h of life.
The electrodes evaluated were: subdermal needles, silver cups, and 2 types of self-adhesive electrodes (solid hydrogel and wet gel). The wet gel electrodes were chosen. They were used on 41 neonates with a mean gestational age of 25.8 ± 1.1 weeks. Good stable impedance was rapidly obtained, without the need of excessive manipulations, and no skin injuries were observed. The satisfaction of the staff involved in positioning them was very high.
The self-adhesive disposable electrodes with wet gel and integrated cable enabled the electrodes to be positioned rapidly and provided continuous non-invasive and good quality aEEG/cEEG monitoring in the extremely premature infant.
Developmental change of amplitude-integrated electroencephalographic activity in preterm infants with intraventricular hemorrhage
2013, Early Human Development
Citation Excerpt :
Comparative studies of aEEG versus conventional EEG have been performed to assess the sensitivity of the two techniques for neonatal seizure detection [4,5]. In addition, aEEG appears to reflect brain function status in infants with various diseases, such as congenital heart disease [6], bronchopulmonary dysplasia [7], sepsis [8], and periventricular leukomalacia (PVL) [9]. Intraventricular hemorrhage (IVH) is one of the major morbidities in preterm infants.
Amplitude-integrated electroencephalography (aEEG) allows continuous brain function monitoring at bedside.
This prospective cohort study was designed to longitudinally evaluate aEEG tracings at increased postmenstrual age (PMA) in preterm infants with intraventricular hemorrhage (IVH).
Biweekly aEEG recordings were performed on preterm infants < 32 weeks gestational age from 24 to 36 weeks PMA. The tracings were evaluated according to a scoring system adapted from Burdjalov et al.
We analyzed 496 aEEG recordings in 105 preterm infants. The control group consisted of 42 infants with no IVH, whereas the IVH grade I, II, III, and IV groups consisted of 38, 8, 3, and 14 infants, respectively. There were significant differences in the cycling and total maturation scores among the IVH groups at 36 weeks PMA (p = 0.010 and p = 0.006, respectively). The IVH-IV patients maintained low scores in their cycling as their PMA increased, in contrast to their continuity and amplitude scores. The risk factors affecting the aEEG maturation scores at 36 weeks PMA in the IVH-IV patients included seizure events with the administration of antiepileptic drugs and the insertion of external ventricular drains (β = − 0.679 and β = − 0.418, respectively; p = 0.003).
The low cycling scores persisted until 36 weeks PMA in the IVH-IV group.
Early abnormal amplitude-integrated electroencephalography (aEEG) is associated with adverse short-term outcome in premature infants
2012, European Journal of Paediatric Neurology
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However Inder et al.28 using automated advanced spectral analysis of the EEG showed an association between lower spectral edge frequency and the presence and severity of white matter injury in the premature infant, although the recordings were undertaken between 1 and 20 days of life. Kato et al.29 assessed preterm infants with cystic PVL analyzing the aEEG that was obtained by digital conversion from the contemporary conventional electroencephalogram. They demonstrated that the aEEG upper-margin amplitude in infants with cPVL was significantly higher compared to controls.
In preterm infants with IVH the electrocortical background activity is affected and there is a correlation between the severity of cerebral injury to the degree of depression, however the usefulness of the early aEEG recordings has hardly been determined.
To identify early aEEG features that could be used as prognostic markers for severe brain injury in prematures.
In 115 infants, 25–32 wk GA, aEEG recordings during the first 72 h of life were correlated with head ultrasound findings. Continuity (Co), sleep–wake cycling (Cy) and amplitude of the lower border (LB) of the aEEG were evaluated by semi-quantitative analysis.
The infants were divided into four groups based on head ultrasound findings: A (n = 72, normal), B [n = 16, grades 1–2 intraventricular hemorrhage (IVH)], C (n = 21, grades 3–4 IVH) and D (n = 6, periventricular leukomalacia). 18 infants (16 of group C and 2 of group D) died during hospitalization. Significantly lower values of all aEEG features were found in group C infants. The presence of pathological tracings (burst-suppression, continuous low-voltage, flat trace) or discontinuous low-voltage (DLV), the absence of Cy and LB < 3 μV in the initial aEEG displayed a sensitivity of 88.9%, 63% and 51.9% respectively, for severe brain injury. Logistic regression of aEEG features and GA to the presence or absence of severe injury revealed that only Co was significantly correlated to outcome. Using this feature 83.19% of cases were correctly classified.
Pathological tracings or DLV in the initial aEEG is predictive for poor short-term outcome in premature neonates.
Amplitude-integrated electroencephalography use in preterm infants: Current knowledge and applications
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Electrocortical Activity at 7 Days of Life is Affected in Extremely Premature Infants with Patent Ductus Arteriosus
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Amplitude-integrated electroencephalography in preterm infants with cystic periventricular leukomalacia

Abstract

Aim

Methods

Results

Conclusions

Introduction

Section snippets

Patients

Results

Discussion

Conflict of interest statement

Brain dev

Brain dev

Semin fetal neonatal med

Disorganized patterns: chronic-stage EEG abnormality of the late neonatal period following severely depressed EEG activities in early preterm infants

Neuropediatrics

Determination of timing of brain injury in preterm infants with periventricular leukomalacia with serial neonatal electroencephalography

Pediatrics

Prognostic value of EEG depression in preterm infants for later development of cerebral palsy

Neuropediatrics

Chronologic changes in neonatal EEG findings in periventricular leukomalacia

Pediatrics

Early prediction of outcome with aEEG in preterm infants with large intraventricular hemorrhages

Neuropediatrics

Background patterns and sleep–wake cycles on amplitude-integrated electroencephalography in preterms younger than 30 weeks gestational age with peri-/intraventricular haemorrhage

Acta paediatr