Absent cyclicity on aEEG within the first 24 h is associated with brain damage in preterm infants

The Predictive Value of Amplitude-Integrated Electroencephalography for the Neurodevelopmental Outcomes of Preterm Newborns at 12 Months Corrected Age

BACKGROUND

In clinical practice, it is crucial to identify diagnostic methods that can forecast the neurodevelopmental outcomes of very preterm neonates. Our study aimed to assess the predictive significance of amplitude-integrated electroencephalography (aEEG) for the neurodevelopmental outcomes of preterm infants at 12 months corrected age and to establish the cut-off score that could indicate potential neurodevelopmental impairments.

METHODS

Preterm neonates born before 32 weeks of gestational age between June 2020 and July 2022 were included in a prospective manner. Amplitude-integrated electroencephalography recordings were conducted at five age intervals (days 1-3; first, second, third and fourth weeks). Recordings were analyzed using the Burdjalov scoring system. The neurodevelopment assessment with Bayley Scales of Infant Development-Second Edition was carried out at 12 months corrected age.

RESULTS

A total of 140 newborns were included in the study. Neurodevelopment was assessed in 108 infants at 12 months corrected age. Higher total aEEG Burdjalov scores were observed in groups with normal cognitive and motor development. The most sensitive and specific score for prediction of cognitive impairment in 12 months corrected age was an aEEG evaluation of 5.5 according to Burdjalov score within the first three days. The most sensitive and specific score for prediction of motor impairment was 8.5 within the first week.

CONCLUSIONS

According to our research there is currently not enough data to accurately foresee the development of newborns at 12 months corrected age according to early aEEG test results. However, conducting a research with bigger sample size and repeated evaluations at a later age might increase the prognostic value of aEEG. In this study cut-off scores of aEEG performed early in life to predict later neurodevelopment outcomes were determined.

aEEG in the first 3 days after extremely preterm delivery relates to neurodevelopmental outcomes

OBJECTIVES

Investigate relationships between aEEG in the first 72 h in extremely preterm infants with 1) infant, medical, and environmental factors, and 2) infant feeding and neurobehavioral outcomes at term and school-age.

METHODS

Sixty-four preterm infants (≤28 weeks gestation) were enrolled within the first 24-hours of life and had two-channel aEEG until 72 h of life. Standardized neurobehavioral and feeding assessments were conducted at term, and parent-reported outcomes were documented at 5-7 years.

RESULTS

Lower aEEG Burdjalov scores (adjusted for gestational age) were related to vaginal delivery (p = 0.04), cerebral injury (p = 0.01), Black race (p < 0.01) and having unmarried parents (p = 0.02). Lower Burdjalov scores related to less NICU Network Neurobehavioral Scale arousal (p = 0.002) at term and poorer BRIEF global executive function (p = 0.004), inhibition (p = 0.007), working memory (p = 0.02), material organization (p = 0.0008), metacognition (p = 0.01), and behavioral regulation (p = 0.02) at 5-7 years. We did not observe relationships of early aEEG to feeding outcomes or sensory processing measures.

CONCLUSION

Early aEEG within the first 72 h of life was related to medical and sociodemographic factors as well as cognitive outcome at 5-7 years.

Nomogram for Early Prediction of Outcome in Coma Patients with Severe Traumatic Brain Injury Receiving Right Median Nerve Electrical Stimulation Treatment

BACKGROUND

Accurate outcome prediction can serve to approach, quantify and categorize severe traumatic brain injury (TBI) coma patients for right median electrical stimulation (RMNS) treatment, which can support rehabilitation plans. As a proof of concept for individual risk prediction, we created a novel nomogram model combining amplitude-integrated electroencephalography (AEEG) and clinically relevant parameters.

METHODS

This study retrospective collected and analyzed a total of 228 coma patients after severe TBI in two medical centers. According to the extended Glasgow Outcome Scale (GOSE), patients were divided into a good outcome (GOSE 3-8) or a poor outcome (GOSE 1-2) group. Their clinical and biochemical indicators, together with EEG features, were explored retrospectively. The risk factors connected to the outcome of coma patients receiving RMNS treatment were identified using Cox proportional hazards regression. The discriminative capability and calibration of the model to forecast outcome were assessed by C statistics, calibration plots, and Kaplan-Meier curves on a personalized nomogram forecasting model.

RESULTS

The study included 228 patients who received RMNS treatment for long-term coma after a severe TBI. The median age was 40 years, and 57.8% (132 of 228) of the patients were male. 67.0% (77 of 115) of coma patients in the high-risk group experienced a poor outcome after one year and the comparative data merely was 30.1% (34 of 113) in low-risk group patients. The following variables were integrated into the forecasting of outcome using the backward stepwise selection of Akaike information criterion: age, Glasgow Coma Scale (GCS) at admission, EEG reactivity (normal, absence, or the stimulus-induced rhythmic, periodic, or ictal discharges (SIRPIDs)), and AEEG background pattern (A mode, B mode, or C mode). The C statistics revealed that the nomograms' discriminative potential and calibration demonstrated good predictive ability (0.71).

CONCLUSION

Our findings show that the nomogram model using AEEG parameters has the potential to predict outcomes in severe TBI coma patients receiving RMNS treatment. The model could classify patients into prognostic groups and worked well in internal validation.

Amplitude-integrated EEG recorded at 32 weeks postconceptional age. Correlation with MRI at term

OBJECTIVE

The study aims to establish the role of late aEEG (scored by Burdjalov) in predicting brain maturation as well as abnormalities evaluated at term equivalent age (TEA) by brain MRI.

METHODS

91 infants born before 30 wks gestation underwent an aEEG monitoring at 32 wks postconceptional age (PCA). aEEG, was correlated with TEA MRI, scored by Kidokoro.

RESULTS

A significant correlation between the aEEG score and the MRI scores was found. The same results were obtained for the aEEG continuity score; cyclicity and bandwidth scores were associated with grey matter and cerebellar MRI items. Moreover, a correlation between aEEG and cEEG recorded both at 32 and 40 wks PCA, was found.

CONCLUSIONS

aEEG monitoring can be predictive of MRI findings at TEA, suggesting that it could be implemented as a useful tool to support ultrasound to help identify neonates who will benefit from early intervention services.

Dexmedetomidine affects cerebral activity in preterm infants

The use of dexmedetomidine (DEX) has been extended in preterm newborns, but the effects on cerebral activity and their relationship with haemodynamic changes has not been studied.We retrospectively studied the effects of DEX administered to 10 preterm newborns, assessing amplitude-integrated EEG (aEEG) parameters, brain regional SO₂ (brSO₂), heart rate, non-invasive mean blood pressure (MBP), transcutaneous oxygen saturation (SpO₂), venous pCO2 and haemoglobin (Hb) values, in two 6-hour periods: one starting 6 hours before the beginning of DEX perfusion and the other 6 hours afterwards.DEX infusion led to brSO₂ decrease not associated to heart rate, MBP, SpO₂, Hb or pCO2 variation, which suggests that brSO₂ decrease could be related to local vasoconstriction. DEX infusion led to prolongation of interburst interval and reduction of cycling. Such effects, not been described so far, should be considered in the assessment of aEEG traces after DEX administration to avoid misinterpretations regarding patient's prognosis. More studies are needed to assess the safety of DEX use in the newborn.

Evaluation of the suitability and clinical applicability of different electrodes for aEEG/cEEG monitoring in the extremely premature infant

INTRODUCTION

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.

POPULATION AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

Can EEG accurately predict 2-year neurodevelopmental outcome for preterm infants?

OBJECTIVE

Establish if serial, multichannel video electroencephalography (EEG) in preterm infants can accurately predict 2-year neurodevelopmental outcome.

DESIGN AND PATIENTS

EEGs were recorded at three time points over the neonatal course for infants <32 weeks' gestational age (GA). Monitoring commenced soon after birth and continued over the first 3 days. EEGs were repeated at approximately 32 and 35 weeks' postmenstrual age (PMA). EEG scores were based on an age-specific grading scheme. Clinical score of neonatal morbidity risk and cranial ultrasound imaging were completed.

SETTING

Neonatal intensive care unit at Cork University Maternity Hospital, Ireland.

MAIN OUTCOME MEASURES

Bayley Scales of Infant Development III at 2 years' corrected age.

RESULTS

Sixty-seven infants were prospectively enrolled in the study and 57 had follow-up available (median GA 28.9 weeks (IQR 26.5-30.4)). Forty had normal outcome, 17 had abnormal outcome/died. All EEG time points were individually predictive of abnormal outcome; however, the 35-week EEG performed best. The area under the receiver operating characteristic curve (AUC) for this time point was 0.91 (95% CI 0.83 to 1), p<0.001. Comparatively, the clinical course AUC was 0.68 (95% CI 0.54 to 0.80, p=0.015), while abnormal cranial ultrasound was 0.58 (95% CI 0.41 to 0.75, p=0.342).

CONCLUSION

Multichannel EEG is a strong predictor of 2-year outcome in preterm infants particularly when recorded around 35 weeks' PMA. Infants at high risk of brain injury may benefit from early postnatal EEG recording which, if normal, is reassuring. Postnatal clinical complications can contribute to poor outcome; therefore, we state that a later EEG around 35 weeks has a role to play in prognostication.

Behavioral-state development and sleep-state differentiation during early ontogenesis

Sleep is a key process in neurodevelopment and essential for the maturation of fundamental brain functions. Premature birth can disturb the initial steps of sleep maturation, which may contribute to the impairment of neurodevelopment. It is thus fundamental to understand the maturation of the various sleep states and the quality of cerebral function in each vigilance state, as well as the development of sleep cyclicity, in at-risk neonatal infants, particularly those born premature. The objective of this review is to provide a precise description of sleep states and cycles and their rhythmic organization in premature and term newborns according to their gestational age. Technical aspects of polysomnography, which requires a high level of expertise in neonates, are also described. Principles of the visual interpretation of polysomnography, including the simultaneous analysis of behavioral (spontaneous motricity and eye movements), polysomnographic parameters (electro-oculogram, electrocardiogram, respiration), and electroencephalography patterns are presented. The neurophysiology of sleep ontogenesis and its interaction with brain maturation are discussed, highlighting the crucial role of sleep states and their duration in premature newborns. In particular, the involvement of myoclonic twitches in functional connectivity in sensorimotor development is discussed. Indeed, sleep quality, determined by combined polysomnographic parameters, reflects either normal or pathological developmental processes during the neonatal period. The fundamental place of neurophysiological explorations in the early detection of sleep disorders is discussed, as well as their potential consequences on neurodevelopmental care to improve the prevention of neurodevelopmental impairment.

[Evaluation of the suitability and clinical applicability of different electrodes for aEEG/cEEG monitoring in the extremely premature infant]

INTRODUCTION

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.

POPULATION AND METHODS

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 24h of life, and maintained until at least 72h of life.

RESULTS

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.

CONCLUSION

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.

Preterm Brain Injury, Antenatal Triggers, and Therapeutics: Timing Is Key

With a worldwide incidence of 15 million cases, preterm birth is a major contributor to neonatal mortality and morbidity, and concomitant social and economic burden Preterm infants are predisposed to life-long neurological disorders due to the immaturity of the brain. The risks are inversely proportional to maturity at birth. In the majority of extremely preterm infants (<28 weeks' gestation), perinatal brain injury is associated with exposure to multiple inflammatory perinatal triggers that include antenatal infection (i.e., chorioamnionitis), hypoxia-ischemia, and various postnatal injurious triggers (i.e., oxidative stress, sepsis, mechanical ventilation, hemodynamic instability). These perinatal insults cause a self-perpetuating cascade of peripheral and cerebral inflammation that plays a critical role in the etiology of diffuse white and grey matter injuries that underlies a spectrum of connectivity deficits in survivors from extremely preterm birth. This review focuses on chorioamnionitis and hypoxia-ischemia, which are two important antenatal risk factors for preterm brain injury, and highlights the latest insights on its pathophysiology, potential treatment, and future perspectives to narrow the translational gap between preclinical research and clinical applications.

Prognostic value of amplitude-integrated EEG in neonates with high risk of neurological sequelae

OBJECTIVE

To determine the efficacy and the prognostic value of amplitude-integrated electroencephalography (aEEG) in term and near-term neonates with high risk of neurological sequelae.

METHODS

Infants of ≥35 weeks of gestation diagnosed with neonatal encephalopathy or with high risk of brain injury were included. All eligible infants underwent aEEG within 6 h after clinical assessment. The infants were followed up 12 months to evaluate neurological development.

RESULTS

A total of 250 infants were eligible, of which 85 had normal aEEG, 81 had mildly abnormal aEEG, and 84 had severely abnormal aEEG. Of these infants, 168 were diagnosed with different neonatal encephalopathies, 27 with congenital or metabolic diseases, and 55 with high risk of brain injury. In all, 22 infants died, 19 were lost to follow-up, and 209 completed the follow-up at 12 months, of which 62 were diagnosed with a neurological disability. Statistical analysis showed that severely abnormal aEEG predicted adverse neurological outcome with a sensitivity of 70.2%, a specificity of 87.1%, a positive predictive value of 75.6%, and a negative predictive value of 83.7%.

INTERPRETATION

aEEG can predict adverse outcomes in high-risk neonates and is a useful method for monitoring neonates with high risk of adverse neurological outcomes.

Cognitive outcome of early school-aged children born very preterm is not predicted by early short-term amplitude-integrated electroencephalography

AIM

We investigated the association between early amplitude-integrated electroencephalography (aEEG) and cognitive outcome in very preterm infants at early school-age.

METHODS

This prospective cohort study, conducted in the Department of Neonatology, University Hospital Zurich, Switzerland, from 2009 to 2012, comprised of infants born at <32 weeks of gestation, who underwent continuous aEEG recording during the first 4 days of life. Cognitive outcome was assessed with the Kaufman-Assessment Battery for Children at 5 years. Univariate and multivariate logistic regressions were calculated between aEEG parameters and normal cognitive outcome, defined as an intelligence quotient (IQ) of at least 85.

RESULTS

The 118 (52.5% male) infants were born at a mean gestational age of 29.9 weeks and a mean birth weight of 1235 ± 363 g. We followed up 89 children at the age of five, and they had a mean IQ of 97.8 ± 12.7 with 21.3% under 85-and 2.2% had cerebral palsy. Univariate analyses found associations between aEEG measures and normal cognitive outcome, but these were no longer significant after adjustment for confounders. Socioeconomic status and neonatal morbidity were independent predictors of cognitive outcome.

CONCLUSION

Early short-term aEEG did not predict later cognitive outcome in our cohort of very preterm infants.

Decomposition of a Multiscale Entropy Tensor for Sleep Stage Identification in Preterm Infants

Established sleep cycling is one of the main hallmarks of early brain development in preterm infants, therefore, automated classification of the sleep stages in preterm infants can be used to assess the neonate’s cerebral maturation. Tensor algebra is a powerful tool to analyze multidimensional data and has proven successful in many applications. In this paper, a novel unsupervised algorithm to identify neonatal sleep stages based on the decomposition of a multiscale entropy tensor is presented. The method relies on the difference in electroencephalography(EEG) complexity between the neonatal sleep stages and is evaluated on a dataset of 97 EEG recordings. An average sensitivity, specificity, accuracy and area under the receiver operating characteristic curve of 0.80, 0.79, 0.79 and 0.87 was obtained if the rank of the tensor decomposition is selected based on the age of the infant.

A nationwide survey on tracheostomy for very-low-birth-weight infants in Japan

OBJECTIVES

Tracheostomy is indicated for very-low-birth-weight infants (VLBWIs) with prolonged respiratory problems during the perinatal period. The objective of this study is to clarify the epidemiology and risk factors in VLBWIs with tracheostomy after birth in Japan.

METHODS

A total of 40 806 VLBWIs were registered in the Neonatal Research Network of Japan database from 2003 to 2012. Among them, 34 674 infants (85%) survived over 28 days after birth and were subjected to this study. The clinical variables at birth, outcomes at hospital discharge and associated factors for tracheostomy were examined.

RESULTS

The proportion of VLBWIs with tracheostomy did not increase during the study period (mean 36 cases per year, 0.93%). The rate of in-hospital death over 28 days after birth did not differ between tracheostomized and non-tracheostomized infants (2/324, 0.6% vs 314/34 350, 0.9%). Tracheostomized infants more frequently had severe or moderate bronchopulmonary dysplasia (BPD) (75.5% vs 26.0%, P < 0.01) and longer hospitalization (229 days vs 83 days, P < 0.01) than non-tracheostomized infants. Tracheostomized patients showed higher comorbidities with hypoxic ischemic encephalopathy (odds ratio [OR] 10.98, P < 0.01), muscular disease (OR 10.95, P < 0.01), severe or moderate BPD (OR 7.79, P < 0.01), chromosomal abnormality (OR 4.43, P < 0.01) or sepsis (OR 1.78, P < 0.05) at hospital discharge than non-tracheostomized patients.

CONCLUSION

We demonstrated the non-increasing rate in tracheostomy for VLBWIs and such cases were associated with an excellent survival in Japan. These data provide evidence that more attentive care must be practiced in order to reduce the pulmonary and neuromuscular burdens of VLBWIs at birth.

Amplitude-Integrated Electroencephalography Predicts Outcome in Patients with Coma After Acute Brain Injury

Prognostication of coma patients after brain injury is important, yet challenging. In this study, we evaluated the predictive value of amplitude-integrated electroencephalography (aEEG) for neurological outcomes in coma patients. From January 2013 to January 2016, 128 coma patients after acute brain injury were prospectively enrolled and monitored with aEEG. The 6-month neurological outcome was evaluated using the Cerebral Performance Category Scale. aEEG monitoring commenced at a median of 7.5 days after coma onset. Continuous normal voltage predicted a good 6-month neurological outcome with a sensitivity of 93.6% and specificity of 85.2%. In contrast, continuous extremely low voltage, burst-suppression, or a flat tracing was correlated with poor 6-month neurological outcome with a sensitivity of 76.5% and specificity of 100%. In conclusion, aEEG is a promising predictor of 6-month neurological outcome for coma patients after acute brain injury.

Term-equivalent functional brain maturational measures predict neurodevelopmental outcomes in premature infants

BACKGROUND

Term equivalent age (TEA) brain MRI identifies preterm infants at risk for adverse neurodevelopmental outcomes. But some infants may experience neurodevelopmental impairments even in the absence of neuroimaging abnormalities.

OBJECTIVE

Evaluate the association of TEA amplitude-integrated EEG (aEEG) measures with neurodevelopmental outcomes at 24-36 months corrected age.

METHODS

We performed aEEG recordings and brain MRI at TEA (mean post-menstrual age of 39 (±2) weeks in a cohort of 60 preterm infants born at a mean gestational age of 26 (±2) weeks. Forty-four infants underwent Bayley Scales of Infant Development, 3rd Edition (BSID-III) testing at 24-36 months corrected age. Developmental delay was defined by a score greater than one standard deviation below the mean (<85) in any domain. An ROC curve was constructed and a value of SEF90 < 9.2, yielded the highest sensitivity and specificity for moderate/severe brain injury on MRI. The association between aEEG measures and neurodevelopmental outcomes was assessed using odds ratio, then adjusted for confounding variables using logistic regression.

RESULTS

Infants with developmental delay in any domain had significantly lower values of SEF90. Absent cyclicity was more prevalent in infants with cognitive and motor delay. Both left and right SEF90 < 9.2 were associated with motor delay (OR left: 4.7(1.2-18.3), p = 0.02, OR right: 7.9 (1.8-34.5), p < 0.01). Left SEF90 and right SEF90 were associated with cognitive delay and language delay respectively. Absent cyclicity was associated with motor and cognitive delay (OR for motor delay: 5.8 (1.3-25.1), p = 0.01; OR for cognitive delay: 16.8 (3.1-91.8), p < 0.01). These associations remained significant after correcting for social risk index score and confounding variables.

CONCLUSIONS

aEEG may be used at TEA as a new tool for risk stratification of infants at higher risk of poor neurodevelopmental outcomes. Therefore, a larger study is needed to validate these results in premature infants at low and high risk of brain injury.

Complex interactions between hypoxia-ischemia and inflammation in preterm brain injury

Children surviving preterm birth have a high risk of disability, particularly cognitive and learning problems. There is extensive clinical and experimental evidence that disability is now primarily related to dysmaturation of white and gray matter, defined by failure of oligodendrocyte maturation and neuronal dendritic arborization, rather than cell death alone. The etiology of this dysmaturation is multifactorial, with contributions from hypoxia-ischemia, infection/inflammation and barotrauma. Intriguingly, these factors can interact to both increase and decrease damage. In this review we summarize preclinical and clinical evidence that all of these factors trigger secondary or chronic inflammation and gliosis. Thus, we hypothesize that these shared pathological features play a key role in a final common pathway that leads to the impaired neural maturation and connectivity and cognitive/motor impairments that are commonly observed in infants born preterm. This raises the possibility that secondary or chronic inflammation may be a viable therapeutic target for delayed interventions to improve neurodevelopmental outcomes after preterm birth.

WHAT THIS PAPER ADDS

Hypoxia-ischemia, infection/inflammation, and barotrauma/volutrauma all contribute to preterm brain injury. Multiple different triggers of preterm brain injury are associated with central nervous system dysmaturation. Secondary brain inflammation may be a viable target to improve neurodevelopment after preterm birth.

Glia and hemichannels: key mediators of perinatal encephalopathy

Perinatal encephalopathy remains a major cause of disability, such as cerebral palsy. Therapeutic hypothermia is now well established to partially reduce risk of disability in late preterm/term infants. However, new and complementary therapeutic targets are needed to further improve outcomes. There is increasing evidence that glia play a key role in neural damage after hypoxia-ischemia and infection/inflammation. In this review, we discuss the role of astrocytic gap junction (connexin) hemichannels in the spread of neural injury after hypoxia-ischemia and/or infection/inflammation. Potential mechanisms of hemichannel mediated injury likely involve impaired intracellular calcium handling, loss of blood-brain barrier integrity and release of adenosine triphosphate (ATP) resulting in over-activation of purinergic receptors. We propose the hypothesis that inflammation-induced opening of connexin hemichannels is a key regulating event that initiates a vicious cycle of excessive ATP release, which in turn propagates activation of purinergic receptors on microglia and astrocytes. This suggests that developing new neuroprotective strategies for preterm infants will benefit from a detailed understanding of glial and connexin hemichannel responses.

Clinical Manifestations and Amplitude-integrated Encephalogram in Neonates with Early-onset Epileptic Encephalopathy

Background:

The patients with early-onset epileptic encephalopathy (EOEE) suffer from neurodevelopmental delay. The aim of this study was to analyze the clinical manifestations and amplitude-integrated encephalogram (aEEG) characteristics of infants with EOEE with onset within the neonatal period, to make early diagnosis to improve the prognosis.

Methods:

One-hundred and twenty-eight patients with neonatal seizure were enrolled and followed up till 1 year old. Sixty-six neonates evolved into EOEE were as the EOEE group, the other 62 were as the non-EOEE (nEOEE) group. Then we compared the clinical and aEEG characteristics between the two groups to analyze the manifestations in neonates with EOEE.

Results:

Compared to the nEOEE group, the incidence of daily seizure attacks, more than two types of convulsions, more than two antiepileptic drugs (AEDs) application, severely abnormal aEEG background, absence of cyclicity, and more than two seizures detection were significantly higher in the EOEE group (P < 0.05) (97% vs. 54.8%; 30.3% vs. 14.5%; 97.0% vs. 25.4%; 39.4% vs. 3.2%; 57.6% vs. 9.7%; and 56% vs. 3.2%, respectively). Severely abnormal background pattern (odds ratio [OR] = 0.081, 95% confidence interval [CI]: 0.009–0.729, P = 0.025) and more than two seizures detection by aEEG (OR = 0.158, 95% CI: 0.043–0.576, P = 0.005) were the independent risk factors for the evolvement into EOEE. The upper and lower margins of active sleep (AS) and quiet sleep (QS) were significantly higher in EOEE group than those of the control group (P < 0.05) (34.3 ± 13.6 vs. 21.3 ± 6.4; 9.9 ± 3.7 vs. 6.7 ± 2.2; 41.2 ± 15.1 vs. 30.4 ± 11.4; and 11.9 ± 4.4 vs. 9.4 ± 4.0; unit: μV, respectively). AS upper margin was demonstrated a higher diagnostic specificity and sensitivity for EOEE than another three parameters according to the receiver operating characteristic curves; the area under the curve was 0.827.

Conclusions:

The clinical characteristics of the neonatal seizure which will evolve into EOEE were more than two AEDs application, high seizure frequency (daily attack), and more than two types of the seizure. Significant high voltage, severely abnormal background, absence of cyclicity, and more than two seizures detected on aEEG were the meaningful indicators to the prediction of EOEE.

Review of sleep-EEG in preterm and term neonates

Neonatal sleep is a crucial state that involves endogenous driven brain activity, important for neuronal survival and guidance of brain networks. Sequential EEG-sleep analysis in preterm infants provides insights into functional brain integrity and can document deviations of the biologically pre-programmed process of sleep ontogenesis during the neonatal period. Visual assessment of neonatal sleep-EEG, with integration of both cerebral and non-cerebral measures to better define neonatal state, is still considered the gold standard. Electrographic patterns evolve over time and are gradually time locked with behavioural characteristics which allow classification of quiet sleep and active sleep periods during the last 10weeks of gestation. Near term age, the neonate expresses a short ultradian sleep cycle, with two distinct active and quiet sleep, as well as brief periods of transitional or indeterminate sleep. Qualitative assessment of neonatal sleep is however challenged by biological and environmental variables that influence the expression of EEG-sleep patterns and sleep organization. Developing normative EEG-sleep data with the aid of automated analytic methods, can further improve our understanding of extra-uterine brain development and state organization under stressful or pathological conditions. Based on those developmental biomarkers of normal and abnormal brain function, research can be conducted to support and optimise sleep in the NICU, with the ultimate goal to improve therapeutic interventions and neurodevelopmental outcome.

Impact of brain injury on functional measures of amplitude-integrated EEG at term equivalent age in premature infants

OBJECTIVE

To evaluate the association between qualitative and quantitative amplitude-integrated EEG (aEEG) measures at term equivalent age (TEA) and brain injury on magnetic resonance imaging (MRI) in preterm infants.

STUDY DESIGN

A cohort of premature infants born at <30 weeks of gestation and with moderate-to-severe MRI injury on a TEA MRI scan was identified. A contemporaneous group of gestational age-matched control infants also born at <30 weeks of gestation with none/mild injury on MRI was also recruited. Quantitative aEEG measures, including maximum and minimum amplitudes, bandwidth span and spectral edge frequency (SEF₉₀), were calculated using an offline software package. The aEEG recordings were qualitatively scored using the Burdjalov system. MRI scans, performed on the same day as aEEG, occurred at a mean postmenstrual age of 38.0 (range 37 to 42) weeks and were scored for abnormality in a blinded manner using an established MRI scoring system.

RESULTS

Twenty-eight (46.7%) infants had a normal MRI or mild brain abnormality, while 32 (53.3%) infants had moderate-to-severe brain abnormality. Univariate regression analysis demonstrated an association between severity of brain abnormality and quantitative measures of left and right SEF₉₀ and bandwidth span (β=-0.38, -0.40 and 0.30, respectively) and qualitative measures of cyclicity, continuity and total Burdjalov score (β=-0.10, -0.14 and -0.12, respectively). After correcting for confounding variables, the relationship between MRI abnormality score and aEEG measures of SEF₉₀, bandwidth span and Burdjalov score remained significant.

CONCLUSION

Brain abnormalities on MRI at TEA in premature infants are associated with abnormalities on term aEEG measures, suggesting that anatomical brain injury may contribute to delay in functional brain maturation as assessed using aEEG.

Amplitude-integrated electroencephalography can predict neurodevelopmental outcome at 12 months of corrected age in very preterm infants

AIM

It is difficult to find diagnostic tools than can reliably predict neurodevelopmental outcomes in very preterm infants in clinical practice. This study evaluated whether amplitude-integrated electroencephalography predicted neurodevelopmental outcome in preterm infants when they reached 12 months of corrected age.

METHODS

Between October 2007 and December 2013, we studied 232 preterm infants (51% male) at Innsbruck Medical University Hospital, Austria. Their mean birthweight was 1264 g, and their mean gestational age was 29.5 weeks. Amplitude-integrated electroencephalography was evaluated using the Burdjalov score, and outcomes were assessed using the Bayley Scales of Infant Development - Second Edition.

RESULTS

The cohort was divided into three subgroups: 154 infants with normal outcomes, 53 infants with moderate delays and 25 infants with severe delays. The amplitude-integrated electroencephalography Burdjalov scores were lower in infants with moderate delays than in infants with normal outcomes and even lower in infants with severe delays. The highest area under the curve (0.776) for the Burdjalov score was at 18-24 hours of life.

CONCLUSION

Our study confirmed the predictive value of amplitude-integrated electroencephalography and showed that this needed to be carried out early in life to provide reliable information on neurodevelopmental outcomes in very preterm infants.

Prognostic Accuracy of Electroencephalograms in Preterm Infants: A Systematic Review

CONTEXT

Brain injury is common in preterm infants, and predictors of neurodevelopmental outcome are relevant.

OBJECTIVE

To assess the prognostic test accuracy of the background activity of the EEG recorded as amplitude-integrated EEG (aEEG) or conventional EEG early in life in preterm infants for predicting neurodevelopmental outcome.

DATA SOURCES

The Cochrane Library, PubMed, Embase, and the Cumulative Index to Nursing and Allied Health Literature.

STUDY SELECTION

We included observational studies that had obtained an aEEG or EEG within 7 days of life in preterm infants and reported neurodevelopmental outcomes 1 to 10 years later.

DATA EXTRACTION

Two reviewers independently performed data extraction with regard to participants, prognostic testing, and outcomes.

RESULTS

Thirteen observational studies with a total of 1181 infants were included. A meta-analysis was performed based on 3 studies (267 infants). Any aEEG background abnormality was a predictor of abnormal outcome. For prediction of a developmental quotient <70 points, cerebral palsy, or death, the pooled sensitivity was 0.83 (95% confidence interval, 0.69-0.92) and specificity 0.83 (95% confidence interval, 0.77-0.87).

LIMITATIONS

All studies were at high risk of bias. Heterogeneity was evident among the studies with regard to the investigated aEEG and EEG variables, neurodevelopmental outcomes, and cutoff values.

CONCLUSIONS

aEEG or EEG recorded within the first 7 days of life in preterm infants may have potential as a predictor for later neurodevelopmental outcome. We need high-quality studies to confirm these findings. Meanwhile, the prognostic value of aEEG and EEG should be used only as a scientific tool.

Hyperbilirubinemia Influences Sleep-Wake Cycles of Term Newborns in a Non-Linear Manner

Hyperbilirubinemia is a common cause for irreversible neuronal influence in the brain of term newborns, while the feature of neurological symptoms associated with hyperbilirubinemia has not been well characterized yet. In the present study, we examined a total of 203 neonates suffering from hyperbilirubinemia with a bedside amplitude-integrated Electroencephalography (aEEG) device, in order to determine whether there is any special change in sleep-wake cycles (SWCs). Among these patients, 14 cases showed no recognizable SWCs with the total serum bilirubin (TSB) level at 483.9–996.2 μmol/L; 75 cases exhibited reduced SWCs with the TSB level at 311.2–688.5 μmol/L; and the rest cases had the normal SWCs. The number of the normal SWCs occurrence had a significant negative correlation with the increased TSB level in a non-linear manner (r = -0.689, p <0.001). In addition, the increased TSB reshaped the structure of SWC by narrowing down the broadband and broadening the narrowband. Spearman’s correlation analysis indicated a significant negative correlation between the TSB level and the ratio of broadband (r = -0.618, p < 0.001), a significant positive correlation between the TSB level and the narrowband ratio (r = 0.618, p < 0.001), respectively. Furthermore, the change of SWC seemed like a continuous phenomenon, and the hyperbilirubinemia caused SWC changes was fit into a loess model in this paper. In summary, the hyperbilirubinemia influenced SWC of term newborns significantly at a non-linear manner, and these results revealed the feature of the neurological sequela that is associated with TSB.

Sleep-wake cycle on amplitude-integrated EEG and neuroimage outcomes in newborns

BACKGROUND

The aim of this study was to evaluate the results of sleep-wake cycle monitoring using amplitude-integrated EEG (aEEG) and neuroimaging in newborn infants with a possible perinatal hypoxic insult, investigate the correlation between the findings, and determine the relevance of the findings to reasonably predict neurological outcome.

METHODS

aEEG was recorded among newborn infants suspected of perinatal asphyxia between November, 2014 and June, 2015 in one neonatal intensive care unit facility. Brain imaging with serial ultrasonography and MRI when available were performed, and the infants were divided into two groups according to findings and potential neurological outcome: Group I (favorable findings) and Group II (severe findings such as high grade intraventricular hemorrhage, cerebral infarction or white matter injury). Established sleep-wake cycle times after birth was compared between the two groups.

RESULTS

Among 107 newborn infants, 85 subjects were classified as Group I and the remaining 22 subjects as Group II. The total number of aEEG sessions was 207 and recording time was 2,796 h with a mean of 14.43 ± 13.40 h per study. Estimated times of cyclicity were earlier in Group I (113.34 h, 95 % CI 82.31-144.37) as compared to Group II (504.39 h, 95 % CI 319.91-688.88; p < 0.001).

CONCLUSIONS

Delayed cyclicity on aEEG has a strong correlation with unfavorable brain neuroimages in newborns with possible perinatal asphyxia. If sleep-wake cycles do not appear during initial period after birth, follow-up aEEG studies are recommended.

TRIAL REGISTRATION

Retrospectively registered Registration number: BD 2015-148 Name of registry: amplitude integrated EEG in neonate Date of registration: September 9, 2015.

Newborns' sleep-wake cycle development on amplitude integrated electroencephalography

BACKGROUND

To observe the development of neonatal sleep among healthy infants of different conceptional age (CA) by analyzing the amplitude-integrated electroencephalography (aEEG) of their sleep-wake cycles (SWC).

METHODS

Bedside aEEG monitoring was carried out for healthy newborns from 32 to 46 weeks CA between September 1, 2011 and August 30, 2012. For each aEEG tracing, mean duration of every complete SWC, number of SWC repetition within 12 hours, mean duration of each narrow and broadband of SWC, mean voltage of the upper edge and lower edge of SWC, mean bandwidth of SWC were counted and calculated. Analysis of the correlations between voltages or bandwidth of SWC and CA was performed to assess the developmental changes of central nervous system of newborns with different CA.

RESULTS

The SWC of different CA on aEEG showed clearly identifiable trend after 32 weeks of CA. The occurrence of SWC gradually increases from preterm to post-term infants; term infants had longer SWC duration. The voltage of upper edge of the broadband decreased at 39 weeks, while the lower edge voltage increases and the bandwidth of broadband declined along with the growing CA. The upper edge of the narrowband dropped while the lower edge rised gradually, especially in preterm stage. The width of the narrowband narrowed down while CA increased.

CONCLUSIONS

The SWC on aEEG of 32-46 weeks infants showed a continuous, dynamic and developmental progress. The appearance of SWC and the narrowing bandwidth of narrowband is the main indicator to identify the CA-dependent SWC from the preterm to the late preterm period. The lower edge of the broadband identifies the term to post-term period.

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.

Early amplitude-integrated EEG monitoring 6 h after birth predicts long-term neurodevelopment of asphyxiated late preterm infants

The present study aimed to assess the prognostic value of early amplitude-integrated electroencephalogram (aEEG) in late preterm infants who were born at a gestational age between 34 0/7 and 36 6/7 weeks for the prediction of neurobehavioral development. Late preterm infants (n = 170) with normal, mild, and severe asphyxia underwent continuous recording of aEEG for 4-6 h starting 6-8 h after delivery. The recordings were analyzed for background pattern, sleep-wake cycle (SWC), and seizures. Survivors were assessed at 18 months by neurological examination and Bayley Scales of Infant Development II. The incidence of adverse neurological outcome in the asphyxia group was significantly higher than in the normal group. For late preterm infants in the asphyxia group, abnormal aEEG pattern had a predictive potential of neurological outcomes with sensitivity of 78.57% (specificity, 87.80%; positive predictive value [PPV], 68.75%; negative predictive value [NPV], 92.31%; power, 85.45%). Non-SWC and intermediate SWC significantly were increased (25.45 and 52.73%, respectively) in the asphyxia group vs. the normal group. SWC pattern had neurological prognosis value in the asphyxia group with sensitivity of 64.29% (specificity, 87.80%; PPV, 64.29%; NPV, 87.80%; power, 81.82%).

CONCLUSION

Early aEEG patterns are important determinants of long-term prognosis of neurodevelopmental outcome in asphyxiated late preterm infants.

Cortical burst dynamics predict clinical outcome early in extremely preterm infants

Intermittent bursts of electrical activity are a ubiquitous signature of very early brain activity. Previous studies have largely focused on assessing the amplitudes of these transient cortical bursts or the intervals between them. Recent advances in basic neuroscience have identified the presence of scale-free 'avalanche' processes in bursting patterns of cortical activity in other clinical contexts. Here, we hypothesize that cortical bursts in human preterm infants also exhibit scale-free properties, providing new insights into the nature, temporal evolution, and prognostic value of spontaneous brain activity in the days immediately following preterm birth. We examined electroencephalographic recordings from 43 extremely preterm infants (gestational age 22-28 weeks) and demonstrated that their cortical bursts exhibit scale-free properties as early as 12 h after birth. The scaling relationships of cortical bursts correlate significantly with later mental development-particularly within the first 12 h of life. These findings show that early preterm brain activity is characterized by scale-free dynamics which carry developmental significance, hence offering novel means for rapid and early clinical prediction of neurodevelopmental outcomes.

Low-voltage pattern and absence of sleep-wake cycles are associated with severe hemorrhage and death in very preterm infants

Amplitude integrated electroencephalogaphy (aEEG) is becoming an important tool for the assessment of cerebral activity in preterm newborns. Describing the relationship between early aEEG patterns and intraventricular hemorrhage (IVH) can improve our knowledge of neurological injury in the preterm newborn. The aim of this prospective study was to identify early changes in the aEEG in premature newborns that could be associated to severe neurological lesion/death. Preterm newborns with a birth weight ≤1,500 g and/or 32 weeks of gestation were included. aEEG monitoring was performed during the first 72 h of life. A qualitative analysis of the aEEG recordings was performed, based on continuity, sleep-wake cycles (SWCs), inferior lower margin amplitude (LMA), and bandwidth (BW). Key outcomes were severe IVH and/or death. Ninety-two subjects were included (mean gestational age 28 weeks). In 28.6 % of subjects with HIV III/IHP, a low-voltage pattern was observed. A statistically significant relationship was found between low-voltage tracings and death and neurological lesion/death. Absent SWCs during the first 72 h were also related to death.

CONCLUSION

Early aEEG patterns can be predictive of neurological outcome in the preterm newborn. Low-voltage tracing and absence of SWCs are associated with severe neurological lesions/death.

Being Born Small for Gestational Age Influences Amplitude-Integrated Electroencephalography and Later Outcome in Preterm Infants

BACKGROUND

The impact of growth restriction on perinatal morbidity is well known, but electroencephalographic (EEG) data on its influence are still scarce.

OBJECTIVES

We aimed to analyze the influence of being born small for gestational age (SGA; defined as a birth weight <10th percentile) on the amplitude-integrated EEG (aEEG) score in the first 2 weeks of life in preterm infants born before 30 weeks of gestation, and its impact on later outcome.

METHODS

aEEG data obtained within the first 2 weeks of life on preterm infants born SGA and before 30 weeks of gestational age (GA) were analyzed retrospectively using a combined score [including background activity, occurrence of sleep-wake cycles (SWC) and suspected seizure activity]. Neurodevelopmental outcome was evaluated at 24 months by means of the Bayley Scales of Infant Development II and a standardized neurological examination.

RESULTS

One hundred and thirty-six patients were included (47 SGA and 89 controls). Infants with SGA had abnormal aEEG scores significantly more often (57 vs. 24%, p = 0.002) than infants born appropriate for gestational age (AGA). They also displayed SWC less frequently (65 vs. 96%, p = 0.001), were more likely to develop seizure activity (15 vs. 4%, p = 0.013) and had a normal neurodevelopmental outcome at the age of 2 years less frequently (36.2 vs. 59.6%, p = 0.02).

CONCLUSION

Preterm infants born SGA and before 30 weeks of GA had less optimal scores on early aEEG and a poorer neurodevelopmental outcome at 24 months than the AGA controls.

Measuring brain activity cycling (BAC) in long term EEG monitoring of preterm babies

Measuring fluctuation of vigilance states in early preterm infants undergoing long term intensive care holds promise for monitoring their neurological well-being. There is currently, however, neither objective nor quantitative methods available for this purpose in a research or clinical environment. The aim of this proof-of-concept study was, therefore, to develop quantitative measures of the fluctuation in vigilance states or brain activity cycling (BAC) in early preterm infants. The proposed measures of BAC were summary statistics computed on a frequency domain representation of the proportional duration of spontaneous activity transients (SAT%) calculated from electroencephalograph (EEG) recordings. Eighteen combinations of three statistics and six frequency domain representations were compared to a visual interpretation of cycling in the SAT% signal. Three high performing measures (band energy/periodogram: R = 0.809, relative band energy/nonstationary frequency marginal: R = 0.711, g-statistic/nonstationary frequency marginal: R = 0.638) were then compared to a grading of sleep wake cycling based on the visual interpretation of the amplitude-integrated EEG trend. These measures of BAC are conceptually straightforward, correlate well with the visual scores of BAC and sleep wake cycling, are robust enough to cope with the technically compromised monitoring data available in intensive care units, and are recommended for further validation in prospective studies.

Cerebral maturation on amplitude-integrated electroencephalography and perinatal exposures in preterm infants

AIM

To determine the associations between perinatal exposures, cerebral maturation on amplitude-integrated encephalography (aEEG) and outcome.

METHODS

During this prospective cohort study, 136 infants ≤30 weeks estimated gestational age received 4 h of aEEG at four time points (between the first 2 weeks of life and term-equivalent age) during hospitalisation. Perinatal factors were documented. Associations between perinatal exposures and Burdjalov-scores were investigated. Neurodevelopmental outcome was assessed at the age of two.

RESULTS

Immature cyclicity on the initial aEEG recording was associated with higher CRIB score (p = 0.01), vaginal delivery (p = 0.02), male gender (p < 0.01) and death (p = 0.01). Perinatal factors associated with lower Burdjalov-scores included cerebral injury (p < 0.01), sepsis (p < 0.01), lower caffeine dose (p = 0.006), prolonged mechanical ventilation (p = 0.002) and death (p < 0.01). Burdjalov-scores at 30 (β = 2.62, p < 0.01) and 34 weeks postmenstrual age (β = 2.89, p = 0.05) predicted motor scores.

CONCLUSION

aEEG measures of cyclicity and Burdjalov-scores in the first 6 weeks of life, with an emphasis on 30 and 34 weeks postmenstrual age, demonstrated associations with perinatal factors known to predict adverse neurodevelopmental outcome.

The prognostic value of amplitude-integrated EEG in full-term neonates with seizures

Neonatal seizures pose a high risk for adverse outcome in survived infants. While the prognostic value of amplitude-integrated electroencephalogram (aEEG) is well established in neonates with encephalopathy and asphyxia, neonatal seizure studies focusing on the direct correlation between early aEEG measurement and subsequent neurologic outcome are scarce. In this study, the prognostic value of aEEG features was systematically analyzed in 143 full-term neonates to identify prognostic indicators of neurodevelopmental outcome. Neonatal aEEG features of background pattern, cyclicity, and seizure activity, as well as the etiology of neonatal seizures, were significantly associated with neurodevelopmental outcome at one year of age. aEEG background pattern was highly associated with neurologic outcomes (χ² = 116.9), followed by aEEG cyclicity (χ² = 87.2) and seizure etiology (χ² = 79.3). Multiple linear regression showed that the four predictors explained 71.2% of the variation in neurological outcome, with standardized β coefficients of 0.44, 0.24, 0.22, and 0.14 for the predictors of aEEG background pattern, cyclicity, etiology, and aEEG seizure activity, respectively. This clinically applicable scoring system based on etiology and three aEEG indices would allow pediatricians to assess the risk for neurodevelopmental impairment and facilitate an early intervention in newborns developing seizures.

Functional brain maturation assessed during early life correlates with anatomical brain maturation at term-equivalent age in preterm infants

BACKGROUND

Amplitude-integrated electroencephalogram (aEEG) is a reliable monitoring tool for electrocortical activity with good predictive value in preterm infants. Magnetic resonance imaging (MRI) is a good neuroimaging tool to detect brain lesions and to evaluate brain maturation. We hypothesized that early aEEG measures, recorded over the first 3 d of life in very preterm infants, correlate with brain maturation and injury score assessed by conventional MRI at term-equivalent age.

METHODS

Thirty-nine infants born at a mean (range) gestational age (GA) of 29.5 (27.0-31.9) wk and birth weight 1,230 (680-2,020) g had continuous aEEG during the first postnatal 72-84 h. aEEG maturity scores and average maximum and minimum amplitudes were evaluated. Conventional brain MRI was performed at 41.2 (37.1-44.1) wk postmenstrual age (PMA) on a 3T GE system and scored qualitatively for injury and maturation.

RESULTS

The average aEEG total maturity score and its cycling subscore were positively and significantly associated with the total MRI maturation score after adjustment for GA, morphine sedation, and PMA at MRI examination. No association was found between the aEEG measures and the MRI injury scores.

CONCLUSION

Early aEEG maturity seems to relate to structural MRI brain maturation at term-equivalent age in preterm infants.

Delayed cyclic activity development on early amplitude-integrated EEG in the preterm infant with brain lesions

BACKGROUND

Maturation of amplitude-integrated electroencephalogram (aEEG) activity is influenced by both gestational age (GA) and postmenstrual age. It is not fully known how this process is influenced by cerebral lesions.

OBJECTIVE

To compare early aEEG developmental changes between preterm newborns with different degrees of cerebral lesions on cranial ultrasound (cUS).

METHODS

Prospective cohort study on preterm newborns with GA <32.0 weeks, undergoing continuous aEEG recording during the first 84 h after birth. aEEG characteristics were qualitatively and quantitatively evaluated using pre-established criteria. Based on cUS findings three groups were formed: normal (n = 78), mild (n = 20), and severe cerebral lesions (n = 6). Linear mixed models for repeated measures were used to analyze aEEG maturational trajectories.

RESULTS

104 newborns with a mean GA (range) 29.5 (24.4-31.7) weeks, and birth weight 1,220 (580-2,020) g were recruited. Newborns with severe brain lesions started with similar aEEG scores and tendentially lower aEEG amplitudes than newborns without brain lesions, and showed a slower development of the cyclic activity (p < 0.001), but a more rapid increase of the maximum and minimum aEEG amplitudes (p = 0.002 and p = 0.04).

CONCLUSIONS

Preterm infants with severe cerebral lesions manifest a maturational delay in the aEEG cyclic activity already early after birth, but show a catch-up of aEEG amplitudes to that of newborns without cerebral lesions. Changes in the maturational aEEG pattern may be a marker of severe neurological lesions in the preterm infant.

Amplitude-integrated electroencephalogram 1 h after birth in a preterm infant with cystic periventricular leukomalacia

We report a preterm infant, who showed abnormal amplitude-integrated electroencephalogram (aEEG) findings 1 h after birth and later developed cystic periventricular leukomalacia (PVL). The patient was a girl with a gestational age of 29 weeks. She was delivered by emergency cesarean section because of placental abruption and intrauterine co-twin demise. Artificial ventilation and administration of surfactant were needed to treat respiratory distress syndrome. Her cardiovascular condition was stable with artificial ventilation. Cranial ultrasonography showed extended cystic PVL after 11 days of age. aEEG 1 h after birth showed a consistently inactive pattern that resolved completely 28 h after birth. The neurophysiological findings of this patient suggest that aEEG findings during the very early period after birth provide significant information for predicting PVL.

Early abnormal amplitude-integrated electroencephalography (aEEG) is associated with adverse short-term outcome in premature infants

BACKGROUND

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.

AIM

To identify early aEEG features that could be used as prognostic markers for severe brain injury in prematures.

METHODS

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.

RESULTS

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.

CONCLUSION

Pathological tracings or DLV in the initial aEEG is predictive for poor short-term outcome in premature neonates.

EEG for predicting early neurodevelopment in preterm infants: an observational cohort study

OBJECTIVE

To clarify the prognostic value of conventional EEG for the identification of preterm infants at risk for subsequent adverse neurodevelopment in the current perinatal care and medicine setting.

METHODS

We studied 780 EEG records of 333 preterm infants born <34 weeks' gestation between 2002 and 2008. Serial EEG recordings were conducted during 3 time periods; at least once each within days 6 (first period), during days 7 to 19 (second period), and days 20 to 36 (third period). The presence and the grade of EEG background abnormalities were assessed according to an established classification system. Neurodevelopmental outcomes were assessed at a corrected age of 12 to 18 months.

RESULTS

Of the 333 infants, 33 (10%) had developmental delay and 34 (10%) had cerebral palsy. The presence of EEG abnormalities was significantly predictive of developmental delay and cerebral palsy at all 3 time periods: the first period (n = 265; odds ratio [OR], 4.5; 95% confidence interval [CI], 2.2-9.4), the second period (n = 278; OR, 7.6; 95% CI, 3.6-16), and the third period (n = 237; OR, 5.9; 95% CI, 2.8-13). The grade of EEG abnormalities correlated with the incidence of developmental delay or cerebral palsy in all periods (P < .001). After controlling for other clinical variables, including severe brain injury, EEG abnormality in the second period was an independent predictor of developmental delay (OR, 3.2; 95% CI, 1.1-9.7) and cerebral palsy (OR, 6.8; 95% CI 2.0-23).

CONCLUSIONS

EEG abnormalities within the first month of life significantly predict adverse neurodevelopment at a corrected age of 12 to 18 months in the current preterm survivor.

Neonatal posthemorrhagic hydrocephalus from prematurity: pathophysiology and current treatment concepts

OBJECT

Preterm infants are at risk for perinatal complications, including germinal matrix-intraventricular hemorrhage (IVH) and subsequent posthemorrhagic hydrocephalus (PHH). This review summarizes the current understanding of the epidemiology, pathophysiology, management, and outcomes of IVH and PHH in preterm infants.

METHODS

The MEDLINE database was systematically searched using terms related to IVH, PHH, and relevant neurosurgical procedures to identify publications in the English medical literature. To complement information from the systematic search, pertinent articles were selected from the references of articles identified in the initial search.

RESULTS

This review summarizes the current knowledge regarding the epidemiology and pathophysiology of IVH and PHH, primarily using evidence-based studies. Advances in obstetrics and neonatology over the past few decades have contributed to a marked improvement in the survival of preterm infants, and neurological morbidity is also starting to decrease. The incidence of IVH is declining, and the incidence of PHH will likely follow. Currently, approximately 15% of preterm infants who suffer severe IVH will require permanent CSF diversion. The clinical presentation and surgical management of symptomatic PHH with temporary ventricular reservoirs (ventricular access devices) and ventriculosubgaleal shunts and permanent ventriculoperitoneal shunts are discussed. Preterm infants who develop PHH that requires surgical treatment remain at high risk for other related neurological problems, including cerebral palsy, epilepsy, and cognitive and behavioral delay. This review highlights numerous opportunities for further study to improve the care of these children.

CONCLUSIONS

A better grasp of the pathophysiology of IVH is beginning to impact the incidence of IVH and PHH. Neonatologists conduct rigorous Class I and II studies to advance the outcomes of preterm infants. The need for well-designed multicenter trials is essential because of the declining incidence of IVH and PHH, variations in referral patterns, and neonatal ICU and neurosurgical management. Well-designed multicenter trials will eventually produce evidence to enable neurosurgeons to provide their smallest, most vulnerable patients with the best practices to minimize perioperative complications and permanent shunt dependence, and most importantly, optimize long-term neurodevelopmental outcomes.