Evaluating the relationship between aEEG findings and two-year prognosis in neonates with severe hyperbilirubinemia

OBJECTIVE

Identifying factors that can better predict the prognosis of neonates with hyperbilirubinemia is important. In this study, we aimed to evaluate the relationship between electroencephalography (EEG) findings and two-year prognosis in neonates with severe hyperbilirubinemia.

METHODS & MATERIALS

In a cohort prospective study, we studied neonates with a total serum bilirubin level of higher than 18 mg/dL, who were admitted to the neonatal intensive care unit (NICU) of Ghaem hospital, Mashhad, Iran. EEG was recorded upon admission, for all neonates. Patients' data, including demographic characteristics, admission information, and pregnancy and birth data were gathered by obtaining history from parents and studying case files. Also, the relationship between initial EEG findings and final developmental status was assessed.

RESULTS

Mean and standard deviation age of patients were 5.46 ± 3.13 days and average serum total bilirubin level was 23.97 ± 4.34 mg/dL at admission. Our findings revealed a significant correlation between the presence of trace alternant on EEG and developmental delay (P = .001). Presence of trace alternant waves on initial EEG at admission was significantly associated with developmental delay in the two year (P = .005).

CONCLUSION

These results indicate a relationship between developmental prognosis and the severity of hyper bilirubinemia in neonates. Also, our findings show that the presence of trace alternate waves on the initial EEG is significantly associated with developmental delay of the neonate in the future.

[Cerebral oxygen metabolism and brain electrical activity of healthy full-term neonates in high-altitude areas: a multicenter clinical research protocol]

Further evidence is needed to explore the impact of high-altitude environments on the neurologic function of neonates. Non-invasive techniques such as cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography can provide data on cerebral oxygenation and brain electrical activity. This study will conduct multiple cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography monitoring sessions at various time points within the first 3 days postpartum for healthy full-term neonates at different altitudes. The obtained data on cerebral oxygenation and brain electrical activity will be compared between different altitudes, and corresponding reference ranges will be established. The study involves 6 participating centers in the Chinese High Altitude Neonatal Medicine Alliance, with altitude gradients divided into 4 categories: 800 m, 1 900 m, 2 400 m, and 3 500 m, with an anticipated sample size of 170 neonates per altitude gradient. This multicenter prospective cohort study aims to provide evidence supporting the impact of high-altitude environments on early brain function and metabolism in neonates.

[Effects of antenatal corticosteroid therapy in pregnant women on the brain development of preterm infants as assessed by amplitude-integrated electroencephalography]

OBJECTIVES

To investigate the effects of antenatal corticosteroid (ACS) therapy in pregnant women on the brain development of preterm infants using amplitude-integrated electroencephalography (aEEG).

METHODS

A retrospective analysis was conducted on 211 preterm infants with a gestational age of 28 to 34+6 weeks. The infants were divided into an ACS group (131 cases) and a control group (80 cases) based on whether antenatal dexamethasone was given for promoting fetal lung maturity. The first aEEG monitoring (referred to as aEEG1) was performed within 24 hours after birth, and the second aEEG monitoring (referred to as aEEG2) was performed between 5 to 7 days after birth. The aEEG results were compared between the two groups.

RESULTS

In preterm infants with a gestational age of 28 to 31+6 weeks, the ACS group showed a more mature periodic pattern and higher lower amplitude boundary in aEEG1 compared to the control group (P<0.05). In preterm infants with a gestational age of 32 to 33+6 weeks and 34 to 34+6 weeks, the ACS group showed a higher proportion of continuous patterns, more mature periodic patterns and higher Burdjalov scores in aEEG1 (P<0.05). And the ACS group exhibited a higher proportion of continuous patterns, more mature periodic patterns, higher lower amplitude boundaries, narrower bandwidths, and higher Burdjalov scores in aEEG2 (P<0.05).

CONCLUSIONS

ACS-treated preterm infants have more mature aEEG patterns compared to those not treated with ACS, suggesting a beneficial effect of ACS on the brain development of preterm infants.

Efficacy of Levetiracetam as Add-On Therapy in the Treatment of Seizures in Neonates

INTRODUCTION

There is no consensus regarding the efficacy of add-on therapy with levetiracetam (LEV) in the treatment of seizures in neonates. The aim of this study was to evaluate the efficacy of add-on therapy with LEV for achieving >80% seizure reduction after phenobarbital (PB) treatment.

METHODS

Retrospective cohort study of near term neonates admitted to the neonatal intensive care unit with EEG-confirmed seizures despite treatment with PB as first-line therapy and using LEV as 2nd-, 3rd- or 4th-line treatment. Antiseizure medication was administered according to national guidelines. All neonates were monitored with 2-channel amplitude-integrated electroencephalography. The total seizure burden in minutes, 2 h before and 4 h after administration of LEV, was calculated using raw EEG. Primary outcome was the efficacy of LEV in achieving >80% seizure reduction. The efficacy of additional midazolam (MDZ) and lidocaine (LDC) was also calculated.

RESULTS

A total of 47 full-term neonates were included. The mean total loading dose of LEV was 40 mg/kg (36-44 mg/kg). Seizure etiology consisted of hypoxic-ischemic encephalopathy (n = 11), hemorrhagic or ischemic stroke (n = 16), central nervous system infection (n = 8), genetic (n = 8), metabolic disorders (n = 3), and unknown (n = 1). Following LEV administration, >80% seizure reduction was observed in 17% (8/47) of neonates, whereas it was 23% (6/26) after MDZ and 92% (23/25) after LDC administration.

DISCUSSION

Although the cumulative loading dose of LEV was low and the group of infants studied was heterogeneous, the efficacy of LEV as add-on therapy for the treatment of seizures in neonates was limited. The highest seizure reduction rate was seen after LDC administration.

[A preliminary study on a new method for evaluating brain maturation in preterm infants]

OBJECTIVES

To establish a new method for evaluating the brain maturation of preterm infants based on the features of electroencephalographic activity.

METHODS

A prospective study was conducted on the video electroencephalography (vEEG) and amplitude-integrated electroencephalography (aEEG) recordings within 7 days after birth of preterm infants who had a postmenstrual age (PMA) of 25-36 weeks and met the inclusion criteria. The background activity of aEEG+conventional electroencephalography (cEEG) was scored according to the features of brain maturation as a new evaluation system and was compared with the aEEG evaluation system. The correlations of the evaluation results of the two methods with gestational age (GA), PMA, and head circumference were evaluated. The intervals of the total scores of aEEG+cEEG and aEEG were calculated for preterm infants with different PMAs and were compared between groups. The consistency of the new scoring system was evaluated among different raters.

RESULTS

A total of 52 preterm infants were included. The total scores of aEEG+cEEG and aEEG were positively correlated with GA, PMA, and head circumference (P<0.05), and the correlation coefficient between the total scores of the two systems and PMA and GA was >0.9. The normal score intervals for aEEG+cEEG and aEEG scoring systems were determined in preterm infants with different PMAs as follows: infants with a PMA of less than 28 weeks had scores of 13.0 (11.0, 14.0) points for aEEG+cEEG and 6.0 (4.0, 7.0) points for aEEG; infants with a PMA between 28 and 29+6 weeks had scores of 16.0 (14.5, 17.0) points for aEEG+cEEG and 8.0 (6.0, 8.0) points for aEEG; infants with a PMA between 30 and 31+6 weeks had scores of 18.0 (17.0, 21.0) points for aEEG+cEEG and 9.0 (8.0, 10.0) points for aEEG; infants with between 32 and 33+6 weeks had scores of 22.0 (20.0, 24.5) points for aEEG+cEEG and 10.0 (10.0, 10.8) points for aEEG; infants with a PMA between 34 and 36 weeks had scores of 26.0 (24.5, 27.5) points for aEEG+cEEG and 11.0 (10.0, 12.0) points for aEEG. There were significant differences in the total scores of aEEG+cEEG and aEEG among the different PMA groups (P<0.05). There was a high consistency between different raters when using the scoring system to evaluate the brain maturation of preterm infants (κ=0.86).

CONCLUSIONS

The aEEG+cEEG scoring system established in this study can quantitatively reflect the brain maturation of preterm infants, with a good discriminatory ability between preterm infants with different PMAs and high consistency between different raters.

[A novel method for electroencephalography background analysis in neonates with hypoxic-ischemic encephalopathy]

OBJECTIVES

To explore a new method for electroencephalography (EEG) background analysis in neonates with hypoxic-ischemic encephalopathy (HIE) and its relationship with clinical grading and head magnetic resonance imaging (MRI) grading.

METHODS

A retrospective analysis was performed for the video electroencephalography (vEEG) and amplitude-integrated electroencephalography (aEEG) monitoring data within 24 hours after birth of neonates diagnosed with HIE from January 2016 to August 2022. All items of EEG background analysis were enrolled into an assessment system and were scored according to severity to obtain the total EEG score. The correlations of total EEG score with total MRI score and total Sarnat score (TSS, used to evaluate clinical gradings) were analyzed by Spearman correlation analysis. The total EEG score was compared among the neonates with different clinical gradings and among the neonates with different head MRI gradings. The receiver operating characteristic (ROC) curve and the area under thecurve (AUC) were used to evaluate the value of total EEG score in diagnosing moderate/severe head MRI abnormalities and clinical moderate/severe HIE, which was then compared with the aEEG grading method.

RESULTS

A total of 50 neonates with HIE were included. The total EEG score was positively correlated with the total head MRI score and TSS (r_s=0.840 and 0.611 respectively, P<0.001). There were significant differences in the total EEG score between different clinical grading groups and different head MRI grading groups (P<0.05). The total EEG score and the aEEG grading method had an AUC of 0.936 and 0.617 respectively in judging moderate/severe head MRI abnormalities (P<0.01) and an AUC of 0.887 and 0.796 respectively in judging clinical moderate/severe HIE (P>0.05). The total EEG scores of ≤6 points, 7-13 points, and ≥14 points were defined as mild, moderate, and severe EEG abnormalities respectively, which had the best consistency with clinical grading and head MRI grading (P<0.05).

CONCLUSIONS

The new EEG background scoring method can quantitatively reflect the severity of brain injury and can be used for the judgment of brain function in neonates with HIE.

Sleep assessment in preterm infants: Use of actigraphy and aEEG

OBJECTIVE

Objective methods to monitor the sleep of preterm infants at the neonatal intensive care unit (NICU) are required to prevent potentially adverse neurodevelopmental outcomes. This study aimed to determine the concordance of actigraphy and amplitude-integrated electroencephalogram (aEEG) against gold standard direct observation (DO) in assessing sleep/wake states of typically developing preterm infants.

METHODS

This prospective observational study was conducted in a single center level III NICU. Sleep variables were measured using Philips Respironics Mini-Mitter® Actiwatch-2 for 24 h and compared with 8-h matched data of aEEG and DO. Sensitivity-specificity analysis, Cohen's kappa, prevalence-adjusted and bias-adjusted kappa (PABAK), and Bland Altman plots were generated.

RESULTS

Seventeen preterm infants were recruited. A total of 11252 epochs were studied. Sensitivity (86.4%), agreement rate (67.9%), and predictive value for wake (47.9%) for the actigraphy were highest at the automatic activity threshold whereas specificity (54.5%) and predictive value for sleep (75.5%) were highest at low threshold. The sensitivity of aEEG was 79.3% and the specificity was 54.3%. At all thresholds, the agreement was largely equivalent with low kappas (0.14-0.17) and PABAK coefficients (0.22-0.35) for actigraphy and DO. Moderate agreement was observed between aEEG and DO according to the PABAK coefficient (0.44). Mean differences in sleep parameters were not different between DO and aEEG as well as DO/aEEG and actigraphy at medium threshold (p > 0.05).

CONCLUSIONS

Actigraphy at medium threshold can be used in depicting sleep in typically developing preterm infants at NICU. aEEG may be an alternative adjunctive method to actigraphy for the evaluation of sleep/wake states in the NICU setting.

CLINICAL TRIAL REGISTRATION NUMBER

NCT04145362.

Newborns at high risk for brain injury: the role of the amplitude-integrated electroencephalography

OBJECTIVE

Amplitude-integrated electroencephalography (aEEG) is a simplified bedside neurophysiology tool that has been implemented in the neonatal intensive care unit and studied in an extensive range of clinical applications in the past decade. This critical review aimed to evaluate a variety of clinical applications of aEEG monitoring in diagnosis, clinical management, and prognosis assessment in critically ill neonates.

SOURCES

The databases of Pubmed, SciELO, Lilacs, and Cochrane, books, and other online resources were consulted, as well as sources of professional experiences.

SUMMARY OF FINDINGS

The clinical use of aEEG to access real-time brain function, background activity, and utility in seizures detection has been described. A critical review was realized considering the authors' professional experience. Newborns with hypoxic-ischemic encephalopathy and seizures screening represent the most common studied population. However, several studies have shown interesting applications on preterm infants, newborns with congenital heart disease, and other clinical situations of high risk of injury to the developing brain.

CONCLUSION

The aEEG has shown to be a useful non-invasive bedside monitor that aids in evaluating brain function, background activity, and cyclicity. aEEG findings have also demonstrated good prognostic value in a group of critically ill neonates. The aEEG seizure diagnosis capability has limitations, which have been already well established. The use of neonatal brain monitoring such as aEEG was shown to give valuable information in several high-risk clinical situations.

A practical approach toward interpretation of amplitude integrated electroencephalography in preterm infants

The developing preterm brain is vulnerable to injury, especially during periods of clinical instability; therefore, monitoring the brain may provide important information on brain health. Over the last 2 decades, a growing body of literature has been reported on preterm amplitude integrated electroencephalography (aEEG) with regards to normative data and associations with adverse outcomes. Despite this, the use of aEEG for preterm infants remains mostly a research tool with limited clinical applicability. In this article, we review the literature on normal and abnormal aEEG patterns in preterm infants and propose a stepwise clinical algorithm for aEEG assessment at the bedside that takes into account assessment of maturation and identification of pathological patterns.

CONCLUSION

This algorithm may be used by clinicians at the bedside for interpretation to integrate it in clinical practice for neurological surveillance of preterm infants.

WHAT IS KNOWN

• Studies have reported normative data on aEEG in preterm infants for different gestational ages. • Burst suppression pattern and absent sleep-wake cycling have been described to be associated with brain pathology and adverse outcomes in preterm infants.

WHAT IS NEW

• We have synthesized aEEG characteristics in preterm infants across the spectrum of prematurity reported in the literature. • We present a stepwise approach for clinically applicable interpretation of aEEG in preterm infants.

Outcome Prediction in Neonatal Hypoxic-Ischaemic Encephalopathy Using Neurophysiology and Neuroimaging

OBJECTIVE

The aim of the study was to determine the predictive power of the combined use of neurophysiological (amplitude-integrated electroencephalography [aEEG], near-infrared spectroscopy [NIRS]) methods and neuroimaging (magnetic resonance imaging [MRI]) for long-term outcome prediction in neonates with hypoxic-ischaemic encephalopathy (HIE).

STUDY DESIGN

Prospective cohort study of 56 patients with moderate to severe HIE and hypothermia treatment at the Medical University of Vienna between 2008 and 2020. aEEG and NIRS were recorded continuously over a period of >4 days (102 h) starting at the initiation of hypothermia treatment, MRI was performed at a median age of 8 days. Receiver operating characteristic curves and area under the curve were calculated to evaluate the prognostic ability of aEEG, NIRS, and MRI parameters for outcome assessed via Bayley Scales of Infant Development 3rd edition at 2 years of age.

RESULTS

Combined aEEG and MRI parameters showed highest predictive power regarding long-term outcome. The highest area under the curve values (0.96-0.99) were obtained for aEEG (combination of background pattern and sleep-wake cycling) between 66 and 102 h after initiation of hypothermia in combination with MRI findings. NIRS parameters did not differ significantly between infants with favourable and adverse outcome.

CONCLUSIONS

Combined aEEG and MRI parameter scores were more predictive than single parameter scores. No further improvement was observed when combining aEEG/MRI with NIRS data.

Utilization of Amplitude-Integrated Electroencephalography to Predict Neurologic Function after Resuscitation in Adults with Cardiogenic Cardiac Arrest

BACKGROUND

Amplitude-integrated electroencephalography (aEEG) has been used as a tool to recognize brain activity in children with hypoxic encephalopathy.

OBJECTIVES

To assess the prognostic value of aEEG during the post-resuscitation period of adult cardiogenic cardiac arrest, comatose survivors were monitored within 24 h of a return of spontaneous circulation using aEEG.

METHODS

Forty-two consecutive patients experiencing cardiac arrest were retrospectively enrolled, and a return of spontaneous circulation was achieved in all cases. These patients were admitted to the Coronary Intensive Care Unit due to cardiogenic cardiac arrest. The primary outcome was the best neurologic outcome within 6 months after resuscitation, and the registered patients were divided into two groups based on the Cerebral Performance Category (CPC) scale (CPC 1-2, good neurologic function group; CPC 3-5, poor neurologic function group). All patients received an aEEG examination within 24 h after a return of spontaneous circulation, and the parameters and patterns of aEEG recordings were compared.

RESULTS

Nineteen patients were in the good neurologic function group, and 23 were in the poor group. The four voltage parameters (minimum, maximum, span, average) of the aEEG recordings in the good neurologic function groups were significantly higher than in the poor group. Moreover, the continuous pattern, but not the status epilepticus or burst suppression patterns, could predict mid-term good neurologic function.

CONCLUSIONS

aEEG can be used to predict neurologic outcomes based on the recordings' parameters and patterns in unconscious adults who have experienced a cardiac collapse, resuscitation, and return of spontaneous circulation.

Changes in amplitude-integrated electroencephalography, neuron-specific enolase, and S100B in neonates with brain injury induced by neonatal hyperbilirubinemia and their significance

OBJECTIVE

To explore the changes in amplitude-integrated electroencephalography (aEEG), neuron-specific enolase (NSE), and S100B in neonates with brain injury induced by neonatal hyperbilirubinemia (NHB).

METHODS

67 neonates with brain injury induced by NHB admitted to our hospital from March 2016 to October 2018 were included in a brain injury group (BIG), and 82 neonates with NHB but without brain injury in our hospital during the same period were included in a non-BIG. The two groups were compared regarding the rates of normal and abnormal aEEG results.

RESULTS

The proportion of normal aEEG results in the BIG was significantly lower than that in the non-BIG, and the proportion of moderately and severely abnormal aEEG results in the BIG were both significantly higher than those in the non-BIG. The BIG showed significantly higher NSE and S100B levels than those of the non-BIG. The ROC curve for predicting prognosis showed that the AUC of aEEG, NSE, S100B, and the combined detection are 0.780, 0.754, 0.743, 0.788. The AUC > 0.700 indicated a good predictive value for the prognosis.

CONCLUSION

The combination of aEEG, NSE, and S100B has good value in diagnosing injury induced by NHB and can predict prognosis moderately well.

Amplitude-integrated electroencephalography signals in preterm infants with cerebral hemorrhage

OBJECTIVE

To evaluate whether preterm infants with cerebral hemorrhage show alterations of aEEG signals in the first four weeks of life.

STUDY DESIGN

Preterm infants (n = 536) born before 32 completed weeks of pregnancy at Innsbruck Medical University Hospital were included in the study. AEEG recordings were evaluated for the Burdjalov score and cerebral hemorrhage was diagnosed by cerebral ultrasound.

RESULTS

Eighty preterm infants with cerebral hemorrhage (median gestational age 28.9 weeks, median birth weight 1157 g) and 456 preterm infants without cerebral hemorrhage (median gestational age 30.0 weeks, median birth weight 1300 g) were investigated. Burdjalov total scores were significantly lower in infants with cerebral hemorrhage. Infants with mild cerebral hemorrhage showed higher Burdjalov total scores compared to infants with severe cerebral hemorrhage in the first days of life. A Burdjalov total score of seven or more was predictive for no development of a cerebral hemorrhage, with a highest area under the curve (0.613) at postnatal day three.

CONCLUSION

Preterm infants with cerebral hemorrhage show alterations in aEEG signals in the newborn period. In future aEEG could be used as a supplemental method to monitor preterm infants at risk for cerebral hemorrhage. The use of aEEG in early life could reduce the number of ultrasound examinations and limit cumulative stress and discomfort in preterm infants.

Seizures severity during rewarming can predict seizure outcomes of infants with neonatal hypoxic-ischemic encephalopathy following therapeutic hypothermia

Background

The aim of this study was to examine the predictive value of amplitude-integrated electroencephalography (aEEG) on 12-month seizure outcomes of infants with neonatal hypoxic-ischemic encephalopathy (HIE) treated with therapeutic hypothermia.

Methods

We conducted this retrospective cohort study in a tertiary neonatal intensive care unit between May 2012 and September 2017. Neonates with HIE who received both therapeutic hypothermia (TH) and aEEG were enrolled.

Results

A total of 23 infants (14 boys, nine girls) with a mean gestational age of 38.9 weeks were enrolled. Fifteen (65%) infants had moderate HIE and eight (35%) had severe HIE according to modified Sarnat staging. The mean aEEG recording time was 107.5 h. Twenty (86.9%) infants had seizure activity during the first 24 h after cooling and 14 (60.8%) had seizure activity during the first 24 h after rewarming. At 12 months, five (21.7%) infants had poor seizure outcomes. Repetitive seizures or status epilepticus pattern during the first 24 h after rewarming, but not the first 24 h after cooling, were associated with the presence of epilepsy at 12 months (p = 0.037).

Conclusions

We identified a high incidence of electrographic seizures in infants with neonatal HIE treated with therapeutic hypothermia, and post-neonatal epilepsy in the children who survived after HIE. Repetitive seizures or status epilepticus pattern during the first 24 h after rewarming, but not in the first 24 h after cooling, were associated with the presence of epilepsy at 12 months.

Evaluation of maturity of sleep states in preterm infants using conventional and amplitude-integrated electroencephalography

OBJECTIVE

To determine whether sleep state maturity can be estimated accurately using conventional electroencephalography (cEEG) or amplitude-integrated electroencephalography (aEEG) features concerning sleep in neurologically unimpaired preterm infants.

METHODS

A total of 51 preterm infants were monitored with cEEG-polygraphy and simultaneous aEEG. Sleep state maturity of EEG corresponded to specific postmenstrual age (PMA). PMA on cEEG was blindly estimated according to cEEG patterns (indicated as background continuity, frequencies, and voltages) as well as developmental markers in specific states. PMA on aEEG was blindly estimated based on the cycling score (cycling representing sleep state transitions) according to a pre-established scoring system.

RESULTS

A total of 51 EEGs recorded between 32 and 37 weeks PMA were analysed. A significant relationship between estimated PMA (ePMA) and actual chronological PMA (cPMA) was shown by linear regression both on cEEG (r = 0.93, β = 0.98, 95% confidence interval (CI) 0.87-1.09, p < 0.001) and aEEG (r = 0.85, β = 0.83, 95% CI 0.69-0.98, p < 0.001). The estimation gap (defined as ePMA minus cPMA) was between -2 and +2 weeks both on cEEG and aEEG. The percentage of estimation gap between -1 and +1 weeks was 96% for cEEG, which was higher than the estimate of 88% for aEEG.

CONCLUSION

Estimated maturity of sleep state was well correlated with cPMA both on cEEG and aEEG. PMA corresponding to state maturity could be estimated within two weeks of actual cPMA using either of these two tools. However, cEEG had higher accuracy compared with aEEG in the evaluation of sleep state maturity.

Early preterm infants with abnormal psychomotor neurodevelopmental outcome at age two show alterations in amplitude-integrated electroencephalography signals

INTRODUCTION

Recent studies showed that neurodevelopment in preterm infants can be predicted by using amplitude-integrated electroencephalography (aEEG)-derived parameters. In our previous study we demonstrated that aEEG could be useful in predicting neurodevelopmental outcome in very preterm infants at the corrected age of 2 years.

AIM

The aim of this study was to further evaluate aEEG for predicting neurodevelopmental outcome at the at the corrected age of 2 years in preterm infants.

METHODS

Between July 2010 and June 2016 440 very preterm infants were eligible for the study at Innsbruck Medical University Hospital. The aEEG was evaluated for the Burdjalov score in 306 preterm infants (mean gestational age 29.5 weeks; range: 24.1-31.9 weeks). At the corrected age of 2 years outcome was assessed by the Bayley Scales of Infant and Toddler Development.

RESULTS

The cohort was divided into three subgroups: 248 infants with normal outcome, 40 infants with delayed outcome and 18 infants with abnormal outcome. Burdjalov scores were lower in infants with delayed outcome than in infants with normal outcome and even lower in infants with abnormal outcome. Post-hoc analysis showed significant differences between normal and delayed psychomotor outcome at 18-24 h (5 (3;6) versus 3 (3;5), p = .024), 30-36 h (6 (4;8) versus 4 (4;6), p = .033), 42-48 h (7 (5;8.5) versus 4 (4;7), p = .003), 54-60 h (7 (6;9) versus 5 (4;7), p = .003), 66-72 h (8 (6;9) versus 6.5 (4.25;7.75), p = .027) and week one (8 (7;10) versus 6.5 (5;8), p = .021). Additionally, when comparing normal to abnormal outcome, a significant difference was found at week four (12 (9;12) versus 8 (7;10), p = .024). The Burdjalov score was only predictive for a delayed psychomotor outcome, presenting the highest area under the curve (0.690) at week two of life.

CONCLUSION

We observed differences in aEEG signals and neurodevelopmental outcome at the corrected age of 2 years, especially for psychomotor outcome. The predictive value of the Burdjalov score regarding neurodevelopmental outcome at the corrected age of 2 years in preterm infants was low.

Effect of Phenobarbitone on Amplitude-Integrated Electroencephalography in Neonates with Hypoxic-Ischemic Encephalopathy during Hypothermia

BACKGROUND

Phenobarbitone induces suppression of cerebral electrical activity on amplitude-integrated electroencephalography (aEEG) in neonates with hypoxic-ischemic encephalopathy (HIE); however, its effect during therapeutic hypothermia (TH) has not been well characterized.

OBJECTIVE

To evaluate the effect of phenobarbitone on aEEG in neonates with HIE undergoing TH.

METHODS

Thirty-five neonates born at ≥350 weeks gestational age (GA), who received phenobarbitone as first-line antiepileptic drug during TH for ≥ Sarnat stage II HIE with aEEG recordings were retrospectively studied. Background pattern, upper and lower margin voltages were characterized for a 30-min period before and 30-60 min after phenobarbitone administration. Primary outcome was presence of severely abnormal aEEG pattern after phenobarbitone administration.

RESULTS

Mean (±SD) GA and median birth weight were 38.2 ± 1.9 weeks and 3.1 (2.5-3.9) kg, respectively. Phenobarbitone (10-20 mg/kg), administered at median age 16.8 h, was associated with background pattern worsening in 19/29 (65.5%) cases. Severe background patterns were more prevalent in post- versus pre-phenobarbitone tracings (21/29 [72%] vs. 11/29 [38%]; p = 0.01). Presence of severe pattern versus either continuous normal voltage or discontinuous normal voltage pattern post-phenobarbitone, (20/25 [80%] vs. 3/8 [38%]; p = 0.036) was associated with death or moderate-to-severe injury on MRI brain. Median time to trace recovery, when measurable, was 4 h (45 min-72 h).

CONCLUSIONS

Phenobarbitone induces significant suppression on aEEG in infants with HIE undergoing TH. Development of severe aEEG background patterns after phenobarbitone may unmask a population at greater risk of abnormal outcome.

Delay in Treatment of Neonatal Seizures: A Retrospective Cohort Study

INTRODUCTION

Neonatal seizures are common and caused by a variety of underlying disorders. There is increasing evidence that neonatal seizures result in further brain damage.

OBJECTIVE

To describe the time interval between diagnosis of amplitude-integrated electroencephalography (aEEG)-confirmed seizures and administration of anti-epileptic drugs (AEDs).

METHODS

Single-centre retrospective cohort study, with full-term infants (n = 106) admitted to a level III neonatal intensive care unit between 2012 and 2017 with seizures confirmed on 2-channel aEEG and corresponding raw electroencephalography traces, treated with AEDs. The time interval between the first seizure on the aEEG registration and AED administration was calculated. Factors associated with early treatment were analysed.

RESULTS

The median time interval of initiating treatment of aEEG-confirmed seizures was 01:50 h (interquartile range 00:43-4:30 h). Treatment of aEEG-confirmed seizures was initiated <1 h in 34/106 infants (32.1%), between 1 and 2 h in 21/106 infants (19.8%), 2-4 h in 23/106 infants (21.7%), 4-8 h in 14/106 infants (13.2%), and ≥8 h in 14/106 infants (13.2%). Seizures treated <1 h were significantly more often recognized by the seizure detection algorithm (SDA) compared to seizures treated >1 h (67 vs. 42%, p = 0.02) and showed more clinical signs (79.4 vs. 37.5%, p < 0.01). There was no difference for out-of-office hours (23.5 vs. 22.2%, p = 0.88).

CONCLUSION

With only 32.1% of the seizures being treated <1 h, there is room for improvement. Timely treatment occurred more often when seizures were clinical or recognised by the SDA. aEEG is a helpful tool for diagnosing seizures 24/7.

Combined Multimodal Cerebral Monitoring and Focused Hemodynamic Assessment in the First 72 h in Extremely Low Gestational Age Infants

BACKGROUND

Characteristic changes in cerebral saturation (CrSO2), amplitude-integrated electroencephalography (aEEG), and echocardiography (ECHO) may be associated with intraventricular hemorrhage (IVH); however, the feasibility of their combined application is not known.

OBJECTIVE

The aim of this work was to investigate the feasibility and safety of combined multimodal cerebral and hemodynamic monitoring in extremely low gestational age (ELGA) infants in the first 72 h after birth.

METHODS

In this prospective -observational study of 50 infants born between 23 + 0 and 27 + 6 weeks gestation, we measured CrSO2 and aEEG, starting <8 h until 72 h of age. Sequential echocardiography and head ultrasound were performed at 4-8, 12-18, 24-30, and 48-60 h of age. The primary outcome was feasibility of multimodal monitoring, defined as >75% of the subjects satisfying at least 3/4 criteria: (a) CrSO2 and (b) aEEG monitoring each for >75% of the time, and (c) at least 2 out of 4 ECHO and (d) head ultrasounds (at least one by age 24 h). Adverse reactions to sensors, desaturation, and bradycardia during ultrasound studies were recorded.

RESULTS

Fifty infants were enrolled over 14 months. Multimodal monitoring was feasible in 49 (98%) infants. Forty-one (82%) infants fulfilled all 4 criteria. Mild erythema below CrSO2 sensors lasting 3-8 h without skin breakdown was noted in 8/50 subjects (16%). Desaturation was noted during 17/197 (8.6%) of the ultrasound studies. In total, 26/50 (52%) infants developed IVH (grade I/II, n = 22; grade III/IV, n = 4).

CONCLUSION

Multimodal monitoring is feasible, safe, and well tolerated in ELGA infants in the first 72 h after birth.

Implementation of amplitude-integrated electroencephalography in tertiary Canadian Neonatal Intensive Care Units-a longitudinal study

Aim

To investigate the implementation of amplitude-integrated electroencephalography (aEEG) as bedside monitoring tool of cerebral function in tertiary Canadian Neonatal Intensive Care Units (NICU) over the past decade.

Methods

Longitudinal study consisting of online surveys of neonatologists on the use of aEEG in 2009 and 2018.

Results

The response rate to the survey was 72 of 149 (49%) in 2009 and 18 of 30 (60%) in 2018, respectively. aEEG has been implemented in almost all (2009: 62.5%; 2018: 94%) tertiary Canadian NICUs. Two-thirds (2009: 67%; 2018: 71%) of the respondents considered information from aEEG tracing helpful in clinical practice. The main indications for aEEG were term neonates with hypoxic ischemic encephalopathy (2009 and 2018: 76%) and seizure detection/surveillance (2009: 88%; 2018: 94%). Teaching on aEEG has been implemented for neonatologists (2018: 100%) and health care providers (2018: 50%) in tertiary Canadian NICUs but there is a lack of standardization of training. Use of aEEG in preterm neonates (2009: 37%, 2018: 33%) and application of aEEG in research (18% reported occasional use) is less common.

Conclusion

aEEG is well established in tertiary Canadian NICUs to monitor cerebral function and detect seizure activity. There is a need to develop formalized aEEG training programs and methods to assess competence. Further implementation of aEEG in preterm neonates and research is desirable.

Usefulness of two-channel amplitude-integrated EEG recording in a neonatal setting

INTRODUCTION

The development of two-channel aEEG monitors in recent years has allowed for the detection of unilateral brain lesions, and for guided decision-making in real time for infants admitted to the neonatal unit.

OBJECTIVE AND METHODS

To highlight some of the main clinical situations in NICU where two-channel amplitude-integrated electroencephalography may provide important additional information to one-channel monitoring. aEEG recordings were obtained from Olympic Brainz^® Monitor, which records a two-channel aEEG as well as a raw EEG from two electrodes over each hemisphere.

RESULTS

This article describes the advantages of the use of the two-channel aEEG in different clinical scenarios of the newborn infant: infarct, brain malformation, subdural hygroma, subgaleal bleeding, and preterm brain damage.

CONCLUSIONS

Two-channel monitoring allows the detection of asymmetries in aEEG trends and/or epileptic activity that may reflect unilateral brain pathology, and it conditions diagnostic and therapeutic approaches in clinical practice.

Amplitude-integrated electroencephalography shows alterations in children born preterm displaying poor literacy precursor skills

AIM

To assess whether amplitude-integrated electroencephalography (aEEG) alterations in the newborn period are associated with poor precursor skills of literacy at five years of age in children born preterm.

METHODS

Between October 2007 and September 2011 248 preterm infants were eligible for the study at Innsbruck Medical University Hospital. aEEG was analysed for dominating background activity, calculation of the percentage of continuous activity, the Burdjalov scoring system, the minimum, mean and maximum amplitude. At the age of five years, we evaluated preterm born children by the Bielefelder screening (BISC) to assess for early diagnosis of reading problems and weak spelling and classified them as normal performers (n = 64) or poor performers (n = 20). Completion of testing was not possible for one infant.

RESULTS

The minimum amplitude was significantly lower in the poor BISC performance group as compared to the normal BISC performance group at postnatal week two. The percentage of continuous background activity was significantly higher in infants with normal BISC performance than in infants with poor BISC performance at postnatal week three.

CONCLUSION

Children with poor developed precursor skills of literacy showed alterations in aEEG signals. The aEEG could be useful in further diagnosing preterm infants at risk for developmental complications.

Early Amplitude-Integrated Electroencephalography Predicts Long-Term Outcomes in Term and Near-Term Newborns With Severe Hyperbilirubinemia

BACKGROUND

We aimed to determine the predictive neurological prognostic value of early amplitude-integrated electroencephalography (aEEG) in term and near-term neonates with severe hyperbilirubinemia compared with cranial magnetic resonance imaging (MRI) and auditory brainstem response (ABR).

METHODS

Infants of ≥35 weeks of gestation with severe hyperbilirubinemia (total serum bilirubin [TSB] ≥340 μmol/L) or with hyperbilirubinemia (TSB ≥257 μmol/L) in association with bilirubin-induced neurological dysfunction were recruited. All the subjects had an aEEG after being admitted to the neonatal intensive care unit, whereas cranial MRI and ABR were performed when TSB had come down to the normal range. All the infants were followed up to 12 months.

RESULTS

During the study period, 77 of 83 infants were eligible, of which 71 had severe hyperbilirubinemia and six had hyperbilirubinemia in association with bilirubin-induced neurological dysfunction. Thirty-three infants were diagnosed with acute bilirubin encephalopathy (ABE), two of whom died of ABE, and 62 completed the follow-up, of which 12 infants had adverse outcomes. Sixty-four infants underwent aEEG, 40 infants had cranial MRI, and 39 infants had ABR. Logistic regression and the receiver-operator characteristic curve analysis showed that the ability of severely abnormal aEEG to predict adverse neurological outcomes in severe hyperbilirubinemia was no better than abnormal ABR, with a sensitivity of 35.7% versus 83.3%, a specificity of 92.0% versus 74.1%, a positive predictive value of 55.6% versus 58.8%, and a negative predictive value of 83.6% versus 90.9%.

CONCLUSIONS

Early aEEG could predict adverse neurodevelopmental outcomes in neonates with severe hyperbilirubinemia, although the sensitivity was lower than ABR.

Seizures in Premature Infants Born at Less than 28 Weeks' Gestation

BACKGROUND

The incidence of seizures in the neonatal period is thought to be high due to a lower seizure threshold of the immature brain. Data on seizures in extremely premature infants are scarce.

OBJECTIVES

The aim of this study was to determine whether seizures are an independent risk factor for in-hospital death and to determine the incidence of seizures in extremely premature infants.

METHODS

This was a retrospective cohort study. Included were infants born under 28 weeks' gestation and monitored with amplitude-integrated electroencephalography (aEEG) over the first 3 days of life. The number and duration of seizures was retrieved from aEEG recordings together with clinical data. The association of seizures and other parameters with mortality was assessed using univariable analyses methods. Relevant parameters were used for a multivariable Cox regression analysis.

RESULTS

Overall, 229 infants were included in the study. Forty-six infants had at least one seizure episode yielding an incidence of 20%. In univariable analyses, gestational age (p < 0.001), birthweight Z-score (p < 0.001), seizures (p = 0.025), suppressed background aEEG (p < 0.001), and severe intraventricular hemorrhage (IVH; p < 0.001) were associated with death before discharge. In multivariable analysis, gestational age (HR = 0.61, p < 0.001), background aEEG activity (HR = 0.30, p < 0.001), birth weight Z-score (HR = 0.51, p = 0.04), and severe IVH (HR = 2.60, p < 0.001) were found to be significant predictors of mortality while the presence of seizures in the first 3 days of life trended to significantly predict an increased risk of mortality (HR = 1.53, p = 0.09).

CONCLUSIONS

Although seizure incidence was relatively high in this cohort of extremely preterm infants and infants with seizures were more likely to die, seizures alone are not a predictor for early death. However, they may be an important indicator of pathologies that are not immediately diagnosed yet could eventually lead to death among this vulnerable population.

Swedish consensus reached on recording, interpretation and reporting of neonatal continuous simplified electroencephalography that is supported by amplitude-integrated trend analysis

Continuous monitoring of electroencephalography (EEG), with a focus on amplitude-integrated EEG (aEEG), has been used in neonatal intensive care for decades. A number of systems have been suggested for describing and quantifying aEEG patterns. Extensive full-montage EEG monitoring is used in specialised intensive care units. The American Clinical Neurophysiology Society published recommendations for defining and reporting EEG findings in critically ill adults and infants. Swedish neonatologists and clinical neurophysiologists collaborated to optimise simplified neonatal continuous aEEG and EEG recordings based on these American documents.

CONCLUSION

This paper describes the Swedish consensus document produced by those meetings.

Categorization of post-cardiac arrest patients according to the pattern of amplitude-integrated electroencephalography after return of spontaneous circulation

Background

Continuous electroencephalography (cEEG), interpreted by an experienced neurologist, has been reported to be useful in predicting neurological outcome in adult patients post cardiac arrest. Amplitude-integrated electroencephalography (aEEG) is a type of quantitative EEG and is easily interpreted by a non-neurologist. A few studies have shown the effectiveness of aEEG in prognostication among adult patients post cardiac arrest. In this study, we hypothesized that the pattern of aEEG after return of spontaneous circulation (ROSC) could successfully categorize patients post cardiac arrest according to their expected neurological outcome.

Methods

We assessed the comatose survivors of out-of-hospital cardiac arrest who received targeted temperature management with midazolam-based sedation and were monitored with aEEG at our tertiary emergency care center from January 2013 to June 2017. We categorized the patients into categories 1 (C1) to 4 (C4). C1 included patients who regained continuous normal voltage (CNV) within 12 h post ROSC, C2 included those who recovered CNV 12–36 h post ROSC, C3 included those who did not recover CNV before 36 h post ROSC, and C4 included those who had burst suppression at any time post ROSC. We evaluated the outcomes of neurological function for each category at hospital discharge. A good outcome was defined as a cerebral performance category of 1 or 2.

Results

A total of 61 patients were assessed (median age, 60 years), among whom 42 (70%) had an initial shockable rhythm, and 52 (85%) had cardiac etiology. Of all 61 patients, 40 (66%) survived to hospital discharge and 27 (44%) had a good neurological outcome. Of 20 patients in C1, 19 (95%) had a good outcome, while the percentage dropped to 57% among C2 patients. No patients in C3 or C4 had a good outcome. Three patients could not be classified into any category.

Conclusions

The pattern of aEEG during the early post-cardiac-arrest period can successfully categorize patients according to their neurological prognoses and could be used as a potential guide to customize post-cardiac-arrest care for each patient.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2138-2) contains supplementary material, which is available to authorized users.

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.

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.

New Wavelet Neurovascular Bundle for Bedside Evaluation of Cerebral Autoregulation and Neurovascular Coupling in Newborns with Hypoxic-Ischemic Encephalopathy

Neonatal encephalopathy (NE) resulting from birth asphyxia constitutes a major global public health burden for millions of infants every year, and despite therapeutic hypothermia, half of these neonates have poor neurological outcomes. As new neuroprotective interventions are being studied in clinical trials, there is a critical need to establish physiological surrogate markers of therapeutic efficacy, to guide patient selection and/or to modify the therapeutic intervention. The challenge in the field of neonatal brain injury has been the difficulty of clinically discerning NE severity within the short therapeutic window after birth or of analyzing the dynamic aspects of the cerebral circulation in sick NE newborns. To address this roadblock, we have recently developed a new "wavelet neurovascular bundle" analytical system that can measure cerebral autoregulation (CA) and neurovascular coupling (NVC) at multiple time scales under dynamic, nonstationary clinical conditions. This wavelet analysis may allow noninvasive quantification at the bedside of (1) CA (combining metrics of blood pressure and cerebral near-infrared spectroscopy, NIRS) and (2) NVC (combining metrics obtained from NIRS and EEG) in newborns with encephalopathy without mathematical assumptions of linear and stationary systems. In this concept paper, we present case examples of NE using the proposed physiological wavelet metrics of CA and NVC. The new approach, once validated in large NE studies, has the potential to optimize the selection of candidates for therapeutic decision-making, and the prediction of neurocognitive outcomes.

Comparison of Amplitude-Integrated EEG and Conventional EEG in a Cohort of Premature Infants

OBJECTIVE

To compare amplitude-integrated EEG (aEEG) and conventional EEG (EEG) activity in premature neonates.

METHODS

Biweekly aEEG and EEG were simultaneously recorded in a cohort of infants born less than 34 weeks gestation. aEEG recordings were visually assessed for lower and upper border amplitude and bandwidth. EEG recordings were compressed for visual evaluation of continuity and assessed using a signal processing software for interburst intervals (IBI) and frequencies' amplitude. Ten-minute segments of aEEG and EEG indices were compared using regression analysis.

RESULTS

A total of 189 recordings from 67 infants were made, from which 1697 aEEG/EEG pairs of 10-minute segments were assessed. Good concordance was found for visual assessment of continuity between the 2 methods. EEG IBI, alpha and theta frequencies' amplitudes were negatively correlated to the aEEG lower border while conceptional age (CA) was positively correlated to aEEG lower border ( P < .001). IBI and all frequencies' amplitude were positively correlated to the upper aEEG border ( P ≤ .001). CA was negatively correlated to aEEG span while IBI, alpha, beta, and theta frequencies' amplitude were positively correlated to the aEEG span.

CONCLUSIONS

Important information is retained and integrated in the transformation of premature neonatal EEG to aEEG.

SIGNIFICANCE

aEEG recordings in high-risk premature neonates reflect reliably EEG background information related to continuity and amplitude.

A Distinctive Ictal Amplitude-Integrated Electroencephalography Pattern in Newborns with Neonatal Epilepsy Associated with KCNQ2 Mutations

BACKGROUND

Recurrent and prolonged seizures are harmful for the developing brain, emphasizing the importance of early seizure recognition and effective therapy. Amplitude-integrated electroencephalography (aEEG) has become a valuable tool to diagnose epileptic seizures, and, in parallel, genetic etiologies are increasingly being recognized, changing the paradigm of the workup and management of neonatal seizures.

OBJECTIVE

To report the ictal aEEG pattern in neonates with KCNQ2-related epilepsy.

SUBJECTS AND METHODS

In this multicenter descriptive study, clinical data and aEEG findings of 9 newborns with KCNQ2 mutations are reported.

RESULTS

Refractory seizures occurred in the early neonatal period with similar seizure type, including tonic features, apnea, and desaturation. A distinct aEEG seizure pattern, consisting of a sudden rise of the lower and upper margin of the aEEG, followed by a marked depression of the aEEG amplitude, was found in 8 of the 9 patients. Prompt recognition of this pattern led to early treatment with carbamazepine in the 2 most recent cases.

CONCLUSION

Early recognition of the electroclinical phenotype by using aEEG may direct genetic testing and a precision medicine approach with sodium channel blockers in neonates with KCNQ2 mutations.

Prediction of Outcome in Neonates with Hypoxic-Ischemic Encephalopathy II: Role of Amplitude-Integrated Electroencephalography and Cerebral Oxygen Saturation Measured by Near-Infrared Spectroscopy

BACKGROUND

Few data have been published on the combined use of amplitude-integrated electroencephalography (aEEG) and near-infrared spectroscopy (NIRS) for outcome prediction in neonates cooled for hypoxic-ischemic encephalopathy (HIE).

OBJECTIVE

Our aim was to evaluate the predictive values and the most powerful predictive combinations of single aEEG and NIRS parameters and the respective cut-off values with regard to short-term outcomes in HIE II.

METHODS

aEEG and NIRS were prospectively studied at the Medical University of Vienna in the first 102 h of life with regard to magnetic resonance imaging (MRI). Thirty-two neonates diagnosed with HIE II treated with hypothermia were investigated. The measurement period was divided into 6-h epochs. According to MRI, 2 outcome groups were defined and predictive values of aEEG parameters, regional cerebral oxygen saturation (rScO2), and the additional value of both methods combined were studied. Receiver operating curves (ROC) were obtained and area under the curve (AUC) values were calculated. ROC were then used to detect the optimal cut-off points, sensitivity, specificity, positive predictive values, and negative predictive values.

RESULTS

At all time epochs, combined parameter scores were more predictive than single parameter scores. The highest AUC were observed between 18 and 60 h of cooling for the aEEG summation score (0.72-0.84) and for (background pattern + seizures) × rScO2 (0.79-0.85). At 42-60 h sensitivity was similar between those 2 scores (87.5-90.0%), but the addition of NIRS to aEEG led to an increase in specificity (from 52.4-59.1% to 72.7-90.5%).

CONCLUSIONS

In HIE II, aEEG and NIRS are important predictors of short-term outcome. The combination of both methods improves prognostication. The highest predictive abilities were observed between 18 and 60 h of cooling.

Blood pressure and aEEG in the 96h after birth and correlations with neurodevelopmental outcome in extremely preterm infants

BACKGROUND

The management of hypotension immediately after the birth of preterm infants is controversial.

AIM

To investigate the relationship between blood pressure (BP), amplitude-integrated electroencephalography (aEEG), and neurodevelopmental outcome in extremely preterm infants.

METHODS

BP and aEEG were monitored for 96h after birth in 36 infants born at <27weeks gestation. aEEG data were analyzed with Burdjalov scores. Correlations of aEEG findings with BP and several clinical characteristics, including the Score for Neonatal Acute Physiology, Perinatal Extension-II (SNAPPE-II) were explored. A subgroup analysis of BP, aEEG activity, and neurodevelopmental outcome at 18-22months corrected age was also performed. Poor outcome was defined as death or a developmental quotient <70.

RESULTS

Multiple regression analyses revealed no association between BP during the first 48h after birth and aEEG activity. However, BP 48-96h after birth was significantly associated with simultaneous aEEG activity (p<0.001). Within 48h after birth, SNAPPE-II was significantly associated with aEEG activity. Outcome was assessed in 32 infants; 24 and 8 of whom had good and poor outcomes, respectively. aEEG activity was significantly lower in neonates with a poor outcome than those with a good outcome (<0.001). No significant differences in outcome were observed for BP.

CONCLUSION

The activity of aEEG was associated with illness severity during the first 48h after birth. After 48h, there was no effect of illness severity but there was an association with BP. We do not know if hypotension results in a poor outcome. However, aEEG activity was associated with neurodevelopmental outcome.

Prognostic value of the recovery time of continuous normal voltage in amplitude-integrated electroencephalography in out-of-hospital cardiac arrest patients treated with therapeutic hypothermia: a retrospective study

BACKGROUND

The early prediction of neurological outcomes in postcardiac arrest patients treated with therapeutic hypothermia (TH) remains challenging. Amplitude-integrated electroencephalography (aEEG) is a type of quantitative EEG. A particular cutoff time from the return of spontaneous circulation (ROSC) to the recovery of a normal aEEG trace for predicting a good neurological outcome has not yet been established. The purpose of the present study was to examine the relation between neurological outcomes and the continuous normal voltage (CNV) recovery time in adult comatose survivors of cardiac arrest treated with TH and identify the recovery time cutoff for predicting a good neurological outcome.

METHODS

We retrospectively evaluated adult survivors of cardiac arrest with initial shockable rhythm treated with TH and monitored with aEEG. A good outcome was defined as a cerebral performance category (CPC) of 1 or 2 at hospital discharge. A CNV trace was considered as the normal aEEG trace, and the CNV recovery time was defined as the time from ROSC to the initial CNV trace.

RESULTS

The study included 30 patients, and of these patients, 22 had recovery of CNV trace. The median CNV recovery time was shorter among patients with a good outcome than that among those with a poor outcome (10.7 h [interquartile range (IQR), 7.4-15.8 h] vs. 28.6 h [IQR, 26.9-29.3 h]; p = 0.003). The area under the receiver operating characteristic curve of the CNV recovery time for predicting a good neurological outcome was 0.95 (95 % CI 0.86-1; p = 0.003), and the optimal cutoff was 23 h. The recovery of CNV trace within 23 h had a sensitivity of 89 %, specificity of 100 %, positive predictive value of 100 %, and negative predictive value of 86 % for predicting a good neurological outcome in all the patients, including the eight patients without recovery of CNV trace.

CONCLUSIONS

A CNV recovery time cutoff of 23 h might help predict a good neurological outcome in adult survivors of cardiac arrest treated with TH.

Decompressing posthaemorrhagic ventricular dilatation significantly improves regional cerebral oxygen saturation in preterm infants

AIM

This study aimed to delineate the impact of posthaemorrhagic ventricular dilatation (PHVD) on regional cerebral oxygen saturation (rcSO2) in preterm infants before and after ventricular decompression using near-infrared spectroscopy (NIRS).

METHODS

rcSO2 values were recorded, fractional tissue oxygen extraction (FTOE) was calculated, cerebral ultrasound scans were performed, and resistive indices and ventricular width were collected before and after decompression. Where possible, amplitude-integrated electroencephalography (aEEG) and visual evoked potentials (VEPs) were recorded before and after decompression.

RESULTS

We included nine preterm infants: nine with cranial ultrasound scan data, eight with NIRS data, seven with aEEG data and four with VEPs. The resistive index was stable and remained unchanged after decompression in all patients. Before decompression, the mean rcSO2 value was 42.6 ± 12.9% and increased to 55 ± 12.2% after decompression. With increasing ventricular width, FTOE showed a mean value of 0.51 ± 0.05 and decreased to a mean of 0.39 ± 0.12 after decompression. Amplitude-integrated electroencephalography showed a more continuous pattern, and VEPs showed delayed latencies in all patients before intervention, improving afterwards.

CONCLUSION

Near-infrared spectroscopy may be of additional clinical value in progressive PHVD to determine the optimal time point for ventricular decompression.

Amplitude-integrated electroencephalography shows mild delays in electrocortical activity in preterm infants born small for gestational age

AIM

Being born small for gestational age (SGA) seems to be a relevant risk factor for long-term neurologic deficits. We compared the differences between amplitude-integrated electroencephalography (aEEG) signals in very preterm infants born small for gestational age (SGA) and those in age-matched infants born appropriate size for gestational age (AGA).

METHODS

We performed serial aEEG recording on 305 infants: 255 (83.6%) were AGA, and 50 (16.3%) were SGA.

RESULTS

The number of bursts per hour decreased over time in both groups, but was higher in the SGA group at every time point. On day one, it was significantly higher in the SGA group (17.4) than in the AGA group (10.1) (p = 0.016). The total Burdjalov score increased with post-natal age and tended to be lower in SGA infants, but did not reach statistical significance at any time point. The percentage of continuous background patterns increased with post-natal age in both groups, with no significant difference between the groups.

CONCLUSION

Very preterm infants born SGA showed normal maturation of aEEG signals during post-natal life, but they also showed mild delays in electrocortical activity compared to age-matched AGA infants. The predictive value of these findings on neurodevelopmental outcome needs to be further evaluated.

Clinical applications of cerebral function monitoring in neonates

The cerebral function monitor is a device for trend monitoring of changes in the amplitude of the electroencephalogram, typically recorded from one or two pairs of electrodes. Initially developed and introduced to monitor cerebral activity in encephalopathic adult patients or during anaesthesia, it is now most widely used in newborns to assess the severity of encephalopathy and for determining prognosis. The duration and severity of abnormalities of the amplitude-integrated electroencephalogram tracing is highly predictive of subsequent neurologic outcome following neonatal hypoxic-ischemic encephalopathy, including in newborns receiving neuroprotective treatment with prolonged moderate hypothermia. The cerebral function monitor is also used for seizure detection and to monitor response to anticonvulsant therapies. Amplitude-integrated electroencephalography compares well with standard electroencephalography when used to assess the severity of neonatal encephalopathy, but a standard electroencephalogram is still required to provide important information about changes in frequency, and in the synchrony and distribution and other characteristics of cerebral cortical activity. The role of the amplitude-integrated electroencephalogram to identify brain injury in preterm infants remains to be determined.

Prediction of outcome methods assessing short- and long-term outcome after therapeutic hypothermia

Therapeutic hypothermia has significantly changed outcomes for newborns suffering neonatal encephalopathy. Outcome predictors established in the pre-cooling era may not automatically be transferred to the cooling era. This article reviews how the reliability of routinely used outcome predictors has changed. We summarize current knowledge about why this may be the case and when to best obtain and analyze different clinical, biochemical, and imaging outcome markers to predict outcome in cooled asphyxiated newborns.

Cerebral blood volume measurement using near-infrared time-resolved spectroscopy and histopathological evaluation after hypoxic-ischemic insult in newborn piglets

The aim of this study was to assess the relationship between the cerebral blood volume (CBV) measured by near-infrared time-resolved spectroscopy (TRS) and pathological change of the brain in a hypoxic-ischemic (HI) piglet model. Twenty-one anesthetized newborn piglets, including three sham controls, were studied. An HI event was induced by low inspired oxygen. CBV was measured using TRS (Hamamatsu TRS-10). Data were collected before, during, and 6h after the insult. CBV was calculated as the change from the end of the insult. The piglets were allowed to recover from anesthesia for 6h after the insult. At the age of 5 days, the brains of the piglets were perfusion-fixed, and histologic evaluations of brain tissue were performed. The extent of histopathological damage was graded in 0.5-unit intervals on a 9-step scale. CBV increments were well correlated with histopathological scores, especially at 1 and 3h after resuscitation. Spearman's rank-correlation coefficients at 1, 3, and 6h after resuscitation in the gray matter were 0.9016, 0.9127, and 0.6907, respectively. We conclude that an increased CBV after HI insult indicates more marked histological brain damage. CBV measurement immediately after resuscitation provides a more precise prediction of the histological outcome.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Amplitude-integrated electroencephalography shows that doxapram influences the brain activity of preterm infants

AIM

The aim of this study was to measure the brain activity of preterm infants treated with caffeine citrate and doxapram for preterm apnoea, using amplitude-integrated electroencephalography (aEEG), to identify any adverse effects on cerebral function.

METHODS

We analysed the aEEG tracings of 13 preterm infants <30 weeks of gestation before, during and after doxapram treatment, with regard to background activity (percentages of continuous and discontinuous patterns), occurrence of sleep-wake cycling and appearance of electrographic seizure activity. They were also compared with 61 controls without doxapram treatment.

RESULTS

During doxapram treatment, aEEG tracings showed an increase in continuous background activity (19 ± 30% before treatment, 38 ± 35% during treatment) and a decrease in discontinuous patterns. In addition, they showed more frequent electrographic seizure activity (0% before treatment, 15 ± 37% during treatment) and less frequent sleep-wake cycling (92 ± 27% before treatment, 85 ± 37% during treatment) could be observed. These results were confirmed when compared to the control group.

CONCLUSION

Doxapram treatment influences aEEG in preterm infants, showing higher percentages of continuous activity as well as more electrographic seizure activity and less sleep-wake cycling. It should, therefore, be used with caution in very preterm infants.

The use of amplitude-integrated electroencephalography combined with continuous conventional electroencephalography during therapeutic hypothermia for an infant with postnatal cardiac arrest

Introduction

Amplitude-integrated electroencephalography (aEEG) has been employed in therapeutic hypothermia (TH) trials of neonates after perinatal hypoxic-ischemic encephalopathy (HIE). We present a case report involving the use of aEEG during TH with continuous conventional electroencephalography (cEEG) for an infant who experienced postnatal intraoperative cardiac arrest.

Case description

A five-month-old infant developed cardiac arrest during operation. Return of spontaneous circulation was achieved after one hour of cardiopulmonary resuscitation. Therapeutic hypothermia was applied with neuromuscular blockades. During the TH, the brain function and seizures were monitored with aEEG, which can also display continuous cEEG. Intermittent and discrete seizures were detected on aEEG and confirmed with raw cEEG during the TH and rewarming periods. Several kinds of antiepileptic drugs (AEDs) were administered to manage seizures according to the findings of aEEG with cEEG. Seizures were controlled by the treatments, and she showed no clinical seizures after TH and AED discontinuation.

Discussion and evaluation, conclusions

This case indicated the possibility that the use of aEEG with continuous cEEG for a postnatal infant after cardiac arrest was feasible to detect and assess seizures and the effects of antiepileptic therapy while undergoing TH.

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.

Brain monitoring in children

Applying scalp sensors in the operating theater, intensive care, or resuscitation scenarios to detect and monitor brain function is achievable, practical, and affordable. The modalities are complex and the output of the monitor needs careful interpretation. The monitor may have technical problems, and a single reading must be considered with caution. These monitors may have a use for monitoring trends in specific situations, but evidence does not support their widespread use. Nevertheless, research should continue to investigate their role. Future techniques and treatments may show that these monitors can monitor brain function and prevent harm.

Developmental change of amplitude-integrated electroencephalographic activity in preterm infants with intraventricular hemorrhage

BACKGROUND

Amplitude-integrated electroencephalography (aEEG) allows continuous brain function monitoring at bedside.

OBJECTIVES

This prospective cohort study was designed to longitudinally evaluate aEEG tracings at increased postmenstrual age (PMA) in preterm infants with intraventricular hemorrhage (IVH).

METHODS

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.

RESULTS

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).

CONCLUSIONS

The low cycling scores persisted until 36 weeks PMA in the IVH-IV group.

Amplitude-integrated electroencephalography in male newborns <30 weeks' of gestation and unfavourable neurodevelopmental outcome at three years is less mature when compared to females

AIM

To investigate gender-related differences in amplitude-integrated electroencephalography (aEEG) associated with neurodevelopmental outcome at 3 years.

METHODS

Preterms born <30 weeks' gestational age between 2000 and 2002 were prospectively included. aEEGs obtained within the first 2 weeks of life were classified according to aEEG composite scores - including background pattern, sleep-wake cycling (SWC) and seizure activity. Neurodevelopmental outcome was assessed at 3 years of age.

RESULTS

Neurodevelopmental outcome data was available for 148 of 264 eligible infants - 64 showed a normal outcome and 84 an impaired outcome. A logistic regression model revealed a significant independent influence of IVH, analgetic/sedative/anticonvulsant medication, gestational age and gender on aEEG composite scores. Odds ratios for having an abnormal aEEG composite score within the first 2 weeks of life for 'female sex', 'no IVH', 'no medication' and 'gestational age' were calculated. aEEG did not differ between males and females with normal outcomes. In patients with abnormal outcome, however, male preterms showed more burst-suppression patterns and less SWC when compared with female preterms.

CONCLUSION

Being male with an abnormal outcome at 3 years of age is reflected by a less mature early aEEG when compared with the one of females. This association is independent of IVH and medication and was less evident with increasing gestational age.

Placental pathology in full-term infants with hypoxic-ischemic neonatal encephalopathy and association with magnetic resonance imaging pattern of brain injury

OBJECTIVE

To investigate the relationship between placental pathology and pattern of brain injury in full-term infants with neonatal encephalopathy after a presumed hypoxic-ischemic insult.

STUDY DESIGN

The study group comprised full-term infants with neonatal encephalopathy subsequent to presumed hypoxia-ischemia with available placenta for analysis who underwent cerebral magnetic resonance imaging (MRI) within the first 15 days after birth. Macroscopic and microscopic characteristics of the placenta were assessed. The infants were classified according to the predominant pattern of brain injury detected on MRI: no injury, predominant white matter/watershed injury, predominant basal ganglia and thalami (BGT) injury, or white matter/watershed injury with BGT involvement. Maternal and perinatal clinical factors were recorded.

RESULTS

Placental tissue was available for analysis in 95 of 171 infants evaluated (56%). Among these 95 infants, 34 had no cerebral abnormalities on MRI, 27 had white matter/watershed injury, 18 had BGT injury, and 16 had white matter/watershed injury with BGT involvement. Chorioamnionitis was a common placental finding in both the infants without injury (59%) and those with white matter/BGT injury (56%). On multinomial logistic regression analysis, white matter/watershed injury with and without BGT involvement was associated with decreased placental maturation. Hypoglycemia was associated with an increased risk of the white matter/BGT injury pattern (OR,5.4; 95% CI, 1.4-21.4). The BGT injury pattern was associated with chronic villitis (OR, 12.7; 95% CI, 2.4-68.7). A placental weight <10th percentile appeared to be protective against brain injury, especially for the BGT pattern (OR, 0.1; 95% CI, 0.01-0.7).

CONCLUSION

Placental weight <10th percentile was mainly associated with normal cerebral MRI findings. Decreased placental maturation and hypoglycemia <2.0 mmol/L were associated with increased risk of white matter/watershed injury with or without BGT involvement. Chronic villitis was associated with BGT injury irrespective of white matter injury.

Therapeutic hypothermia in neonatal hypoxic ischemic encephalopathy: electrographic seizures and magnetic resonance imaging evidence of injury

OBJECTIVE

To evaluate the electrographic seizure burden in neonates with hypoxic ischemic encephalopathy (HIE) treated with or without therapeutic hypothermia and stratified results by severity of HIE and severity of injury as assessed by magnetic resonance imaging (MRI).

STUDY DESIGN

Between 2007 and 2011, video-electroencephalography (EEG) monitoring was initiated in neonates with moderate to severe HIE. Seizure burden (in seconds) was calculated, and brain MRI scans were quantitatively scored. Data were analyzed by ANOVA, the Student t test, and the χ(2) test.

RESULTS

Sixty-nine neonates with moderate or severe HIE were prospectively enrolled, including 51 who received therapeutic hypothermia and 18 who did not. The mean duration of video-EEG monitoring was longer in the therapeutic hypothermia group (72 ± 34 hours vs 48 ± 34 hours; P = .01). The therapeutic hypothermia group had a lower electrographic seizure burden (log units) after controlling for injury, as assessed by MRI (2.9 ± 0.6 vs 6.2 ± 0.9; P = .003). A reduction in seizure burden was seen in neonates with moderate HIE (P = .0001), but not in those with severe HIE (P = .80). Among neonates with injury assessed by MRI, seizure burden was lower in those with mild (P = .0004) and moderate (P = .02) injury, but not in those with severe injury (P = .90).

CONCLUSION

Therapeutic hypothermia was associated with reduced electrographic seizure burden in neonatal HIE. This effect was detected on video-EEG in infants with moderate HIE, but not in those with severe HIE. When stratified by injury as assessed by MRI, therapeutic hypothermia was associated with a reduced seizure burden in infants with mild and moderate injury, but not in those with severe injury.