Electroencephalography In Neonates Research Articles

Use of Amplitude-integrated electroencephalography in neonates with special emphasis on Hypoxic-ischemic encephalopathy and therapeutic hypothermia

Recognizing the need for neurological monitoring in critically ill neonates such as the other vital parameters, neonatologists, and neurologists is becoming more familiar and comfortable with the use of amplitude-integrated electroencephalography (aEEG) in the neonatal intensive care unit, with minimal training and can be interpreted by care providers without neurophysiology backgrounds. In its simplest form, aEEG is a processed single-channel electroencephalogram that is filtered and time compressed. Current evidence demonstrates that aEEG is useful to monitor cerebral background activity, diagnose and treat seizures, and predict neurodevelopmental outcomes for preterm and term infants. This review aims to explain the fundamentals behind aEEG and its clinical applications specially referring to neonatal hypoxic-ischemic encephalopathy and hypothermia.

Comparison Between Simultaneously Recorded Amplitude Integrated Electroencephalography and Standard Electroencephalography in Neonates with Acute Brain Injury

Comparison Between Simultaneously Recorded Amplitude Integrated Electroencephalography and Standard Electroencephalography in Neonates with Acute Brain Injury

Prognostic value of amplitude-integrated electroencephalography in neonates with hypernatremic dehydration

Objectives: Hypernatremic dehydration in neonates is a condition that develops due to inadequate fluid intake and it may lead to cerebral damage. We aimed to determine whether there was an association between serum sodium levels on admission and aEEG patterns and prognosis, as well as any association between aEEG findings and survival rates and long-term prognosis.Method: The present study included all term infants hospitalized for hypernatremic dehydration in between January 2010 and May 2011. Infants were monitored by aEEG. At 2 years of age, we performed a detailed evaluation to assess the impact of hypernatremic dehydration on the neurodevelopmental outcome.Results: Twenty-one infants were admitted to the neonatal intensive care unit for hypernatremic dehydration. A correlation was found between increased serum sodium levels and aEEG abnormalities. Neurodevelopmental assessment was available for 17 of the 21 infants. The results revealed that hypernatremic dehydration did not adversely affect the long-term outcomes.Conclusion: The follow-up of newborns after discharge is key to determine the risks associated with hypernatremic dehydration. Our results suggest that hypernatremic dehydration had no impact on the long-term outcome. In addition, continuous aEEG monitoring could provide information regarding early prognosis and mortality.

1082 Blood Pressure and Amplitude Integrated Electroencephalography Correlations in Full Term Neonates with Hypoxic Ischaemic Encephalopathy

BackgroundThe correlation between systemic blood pressure (BP) and amplitude integrated electroencephalography (aEEG) in full term neonates with hypoxic ischaemic encephalopathy (HIE) is clinically complex, affecting therapy and prognosis.MethodTerm infants with...

Effects of Morphine and Midazolam on Sleep-Wake Cycling in Amplitude-Integrated Electroencephalography in Post-Surgical Neonates ≥32 Weeks of Gestational Age

Background: Studies of children who undergo major non-cardiac surgery in the neonatal period are needed so that subsequent abnormal neurodevelopment can be better understood. Objective:It was the aim of our study to describe the influence of analgesic and sedative medication on the predominant background pattern and the development of sleep-wake cycling (SWC), as measured on amplitude-integrated electroencephalography (aEEG), in newborn infants born ≥32 weeks’ gestation after major non-cardiac surgery. Methods:This prospective study included infants ≥32⁺⁰ weeks’ gestation admitted to the Neonatal Intensive Care Unit at The Royal Children’s Hospital in Melbourne who were undergoing major non-cardiac surgery. Data on morphine and midazolam given after surgery were recorded and the BrainZ Monitor was applied post-operatively. The maximum levels of morphine and midazolam were assessed as predictors of time to aEEG outcomes using linear regression. Results: Forty-seven eligible infants were included. Emergence of SWC was observed at a mean of 13 h after surgery. The maximum dose of morphine or midazolam was not predictive of time to either any or developed SWC. Conclusions: Despite high doses of morphine and midazolam, SWC was observed on aEEG in neonates ≥32 weeks’ gestational age soon after major non-cardiac surgery. The aEEG background pattern was not affected by the maximum dose of either morphine or midazolam.

Recovery of Sleep-Wake Cycling on Amplitude-Integrated Electroencephalography in Post-Surgical Term Neonates

576 Recovery of Sleep-Wake Cycling on Amplitude-Integrated Electroencephalography in Postsurgical Term Neonates

Use of amplitude-integrated electroencephalography (aEEG) and near infrared spectroscopy findings in neonates with asphyxia during selective head cooling

BackgroundAmplitude-integrated electroencephalogram (aEEG) at <6h is the best single outcome predictor in term infants with perinatal asphyxia at normothermia. Hypothermia treatment has changed the cutoff values for outcome prediction by using time at onset of normal trace and SWC. Cerebral hemodynamics and oxygenation changes detected by near infrared spectroscopy (NIRS) during hypothermia treatment in aphyxiated neonates are not a well known issue. AimThe aim of this study was to investigate the correlations between brain monitoring (amplitude integrated EEG and NIRS) and outcome in asphyxiated full-term infants with moderate/severe hypoxic–ischemic encephalopathy before, during and after hypothermia treatment. MethodTen neonates were recruited for hypothermia treatment by using the cool cap entry criteria. aEEG and NIRS were applied in 10 and 8 patients, respectively with moderate and severe hypoxic–ischemic encephalopathy before, just after brain cooling and rewarming periods. Patterns and voltages of aEEG backgrounds sleep–wake cycles (SWC) and NIRS values (TOI% and FTOE) were recorded. During the follow up their outcomes were assessed by using the Bayley Scales of Infant Development II. ConclusionHypothermia changes the predictive value of early aEEG. Normalization of a baby’s aEEG and the appearance of SWCs while being cooled occurs later. In our study one patient had normal aEEG background pattern at 80 and imminent SWC at 90h after birth and still had normal Bayley scores at 24months. Time to normal aEEG and SWC appearance should be carefully evaluated during the cooling period. NIRS values were different due to the clinical presentations of the patients.

576 Recovery of Sleep-Wake Cycling on Amplitude-Integrated Electroencephalography in Postsurgical Term Neonates

576 Recovery of Sleep-Wake Cycling on Amplitude-Integrated Electroencephalography in Postsurgical Term Neonates

Amplitude-Integrated Electroencephalography in Neonates

Conventional electroencephalography (EEG) has been used for decades in the neonatal intensive care unit for formulating neurologic prognoses, demonstrating brain functional state and degree of maturation, revealing cerebral lesions, and identifying the presence and number of electrographic seizures. However, both the immediate availability of conventional EEG and the expertise with which it is interpreted are variable. Amplitude-integrated EEG provides simplified monitoring of cerebral function, and is rapidly gaining popularity among neonatologists, with growing use in bedside decision making and inclusion criteria for randomized clinical studies. Nonetheless, child neurologists and neurophysiologists remain cautious about relying solely on this tool and prefer interpreting conventional EEG. The present review examines the technical aspects of generating, recording, and interpreting amplitude-integrated EEG and contrasts this approach with conventional EEG. Finally, several proposed amplitude-integrated EEG classification schemes are reviewed. A clear understanding of this emerging technology of measuring brain health in the premature or sick neonate is critical in modern care of the newborn infant.

Role of amplitude-integrated electroencephalography in neonates with cardiovascular compromise

Background Neonates with congenital heart disease (CHD) and persistent pulmonary hypertension of the newborn (PPHN) represent conditions with increased risk of abnormal neurologic outcome. The role of aEEG in disorders where cerebral perfusion/oxygenation is affected by cardiac or pulmonary disease is unknown. Objective The aim of the study was to characterize amplitude-integrated electroencephalography (aEEG) traces in nonasphyxiated neonates with cardiorespiratory compromise secondary to PPHN or CHD. Design/Methods Three hundred sixty-three aEEG records (June 2004-November 2006) were reviewed to identify neonates with a diagnosis of isolated CHD or PPHN. Clinical course, critical interventions, and neurodiagnostic investigation data were collected. The aEEG traces were reviewed by a single blinded expert and classified according to background activity (normal, moderate, or severely abnormal) and presence of seizures. The frequency of abnormal aEEG in both groups and its relationship to recognized markers of abnormal neurologic outcome (electrophysiology [EP] testing and neuroimaging [ultrasound (USS), computerized tomography, and magnetic resonance imaging] was studied. Results Thirty neonates (PPHN [n = 20], CHD [n = 10]) were reviewed at a mean gestation of 39.2 ± 1.1 weeks and weight of 3375 ± 565g. Neonates with PPHN had lower Apgar scores at 1-minute ( P = .02) and were significantly more likely to require inotropic support ( P < .001), inhaled nitric oxide ( P = .001), or surfactant ( P = .01). An abnormal aEEG was found in 15 (50%) babies, but rates did not differ between CHD (n = 6) and PPHN (n = 9). The rates of abnormal composite neurologic outcome (2/3 of abnormal EP, neuroimaging, or neurologic examination) were significantly higher in neonates with abnormal aEEG. An abnormal magnetic resonance imaging was seen in 4 of 5 neonates with abnormal aEEG. Conclusions The risk of abnormal aEEG is high in sick neonates with PPHN or complex CHD. Prospective evaluation of the relationship between aEEG recordings in these disorders and acute cardiorespiratory physiology, comprehensive neuroimaging, and long-term patient outcomes is needed.

Predictive Value of Sequential Electroencephalogram (EEG) in Neonates With Seizures and Its Relation to Neurological Outcome

The aim of this study was to evaluate the relationship of sequential neonatal electroencephalography (EEG) and neurological outcome in neonates with seizures to identify polysomnographic features predictive of outcome. Sequential EEGs recordings of 58 neonates that belonged to 2 historical cohorts of newborns with seizures from the same neonatal intensive care unit and who had follow-up at the Neurodevelopment Clinic of the Hospital São Lucas, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS) in Porto Alegre, Brazil, were analyzed and classified into 4 groups: normal-normal, abnormal-normal, abnormal-abnormal, normal-abnormal. In patients with more than 2 recordings, during the neonatal period, the first EEG was compared with the following more abnormal. A total of 58 pairs of 2 sequential EEGs were analyzed. Considering the first EEG, a statistically significant difference was observed between the relationship of the result of this exam, if it was abnormal, with developmental delay (P = .030) and postnatal death (P = .030). Abnormal background activity was also related to neurodevelopment delay (P = .041). EEG sequences abnormal-abnormal and normal-abnormal significantly correlated to the outcome epilepsy ( P = .015). Abnormal sequential background activity was associated with neurodevelopment delay (P = .006) and epilepsy (P = .041). The burst suppression pattern when present in any EEG correlated with epilepsy (P = .013) and postnatal death (P = .034). Sequential abnormal background patterns in the first and second EEG increased the risk for epilepsy (relative risk [RR] = 1.8; 95% confidence interval [CI] = 1.03-3.0) and neurodevelopment delay (RR = 2.20; 95% CI = 1.3-3.0). Abnormal background activity only in the second electroencephalogram increased the risk for neurodevelopment delay (RR = 2.20; 95% CI = 1.3-3.0). All the neonates (n = 33) with seizures related to probable hypoxic ischemic encephalopathy had abnormalities in the first EEG (P = .030). Postnatal epilepsy was diagnosed in 24 infants (41.4%). Five (20.8%) presented West syndrome, 7 (29.2%) focal symptomatic epilepsy, 6 (25%) generalized symptomatic epilepsy, 2 (8.3%) early myoclonic encephalopathy, 1 (4.2%) early infantile epileptic encephalopathy, and in 3, the epileptic syndrome was undefined (12.5%). All infants (n = 5) with West syndrome had some degree of neurodevelopment delay. In conclusion, our findings suggest that sequential EEG in neonates with seizures has more predictive value to estimate the outcomes of neurodevelopment delay, epilepsy, and postnatal death than a single EEG recording. The abnormal background activity in even 1 EEG of the sequential recordings was more significant to determine neurological outcome than abnormal ictal activity or abnormalities in the organization of sleep state.

High‐resolution electroencephalography and source localization in neonates

Although Electroencephalography (EEG) source localization is being widely used in adults, this promising technique has not yet been applied to newborns because of technical difficulties, such as lack of data concerning the newborn skull conductivity, thickness, and homogeneity. Using a new type of EEG headcap molded on each baby's head, we aimed to determine whether this technique could be adapted to neonates, and to evaluate the importance of these technical difficulties. We carried out EEG source reconstruction of the recordings of five neonates using dipole fit algorithm. We used four different head models for each neonate, obtained from individual MRI scans: normal skull thickness and conductivity of 0.0042 S/m; normal thickness and conductivity of 0.33 S/m; increased thickness and conductivity of 0.0042 S/m; and normal thickness and conductivity with a modeled bregma fontanel. Dipole locations were consistent with MRI and clinical data. The mean difference between the dipole locations in the 0.0042 and the 0.33 S/m skull layer models was 11.6 +/- 2.5 mm, with an average 29.7% decrease in magnitude for the 0.33 S/m model but no significant changes for the dipoles orientation. Skull layer thickness had a large influence on magnitude, but no significant effect on position and orientation. The mean difference between the dipole locations induced by the modeled fontanel was 2.0 +/- 2.1 mm, with an average 2.1% increase in magnitude. Our results show that EEG source localization is feasible in neonates. With further development, the technique may prove useful for neurological evaluation of neonates.

Lack of influence of mild hypothermia on amplitude integrated-electroencephalography in neonates receiving extracorporeal membrane oxygenation

Objective To observe amplitude integrated electroencephalography (aEEG) in neonates receiving ECMO and to determine whether mild hypothermia influenced the aEEG recording. Methods Twenty-six consecutive neonates enrolled in a pilot study of mild hypothermia during ECMO were studied. The first group ( N = 6) was maintained at 37 °C throughout the study period. Subsequent groups were cooled to 36 °C ( N = 4), 35 °C ( N = 5), and finally 34 °C ( N = 6) respectively for 24 h and the final group ( N = 5) to 34 °C for 48 h before being rewarmed to 37 °C. The aEEG was recorded continuously during the first 5 days of ECMO. The aEEG was classified as normal, moderately or severely suppressed and examined for the occurrence of seizures. To assess the effect of temperature, the aEEG was compared over 12 h during the final 6 h of cooling and during the first 6 h once infants were rewarmed. Results No change in aEEG amplitude was noted over the temperature range studied. Of the 26 traces obtained, 16 (62%) were normal throughout, 6 (23%) were intermittently moderately abnormal and 1 (14%) was severely abnormal. Three (11%) traces had periods of frequent seizure activity and these were not associated with clinical manifestations in two neonates. In one infant who suffered a cerebral haemorrhage, the aEEG became abnormal before cranial ultrasound abnormalities were apparent. Conclusions Continuous cerebral monitoring with aEEG is feasible during ECMO and may add information to clinical examination. Mild hypothermia to 34 °C for up to 48 h does not influence the aEEG suggesting that cerebral monitoring with aEEG is possible during mild hypothermia.

Changes in Amplitude-integrated Electroencephalography in Neonates Treated with Extracorporeal Membrane Oxygenation: A Pilot Study

Neonates (n = 20) treated with extracorporeal membrane oxygenation were evaluated with serial amplitude-integrated electroencephalography (aEEG). There was no acute change in aEEG during extracorporeal membrane oxygenation cannulation, nor were there lateralizing effects. An abnormal aEEG predicted death or moderate to severe intracranial neuropathology with sensitivity = 1.0, specificity = 0.75, positive predictive value = 0.86, and negative predictive value = 1.0.