Accuracy of amplitude integrated EEG in a neonatal cohort

Unveiling variability: A systematic review of reproducibility in visual EEG analysis, with focus on seizures

OBJECTIVE

Reproducibility is key for diagnostic tests involving subjective evaluation by experts. Our aim was to systematically review the reproducibility of visual analysis in clinical electroencephalogram (EEG). In this paper, we give data on the scope of EEG features found, and detailed reproducibility data for the most studied feature.

METHODS

We searched four databases for articles reporting reproducibility in clinical EEG, until June 2023. Two raters screened 24 553 citations, and then 2736 full texts. Quality was assessed according to the GRRAS guidelines.

RESULTS

We found 275 studies (268 interrater and 20 intrarater), addressing 606 different EEG features. Only 38 EEG features had been studied in >2 studies. Most studies had <50 patients and EEGs. The most often addressed feature was seizure detection (62 papers). Interrater reproducibility of seizure detection was substantial-to-almost-perfect with experienced raters and raw EEG (kappa .62-.88). With experienced raters and transformed EEG, reproducibility was substantial (kappa .63-.70). Inexperienced raters had lower reproducibility. Seizure lateralization reproducibility was moderate to substantial (kappa .58-.77) but lower than for seizure detection.

SIGNIFICANCE

Most EEG reproducibility studies are done only once. Intrarater studies are rare. The reproducibility of visual EEG analysis is variable. Interrater reproducibility for seizure detection is substantial-to-perfect with experienced raters and raw EEG, less with inexperienced raters or transformed EEG. The results of visual EEG analysis vary within the same rater, and between raters. There is a need for larger collaborative studies, using improved methodology, as well as more intrarater studies of EEG interpretation.

Advances in Electroencephalographic Biomarkers of Neonatal Hypoxic Ischemic Encephalopathy

Electroencephalography (EEG) is a key objective biomarker of newborn brain function, delivering critical, cotside insights to aid the management of encephalopathy. Access to continuous EEG is limited, forcing reliance on subjective clinical assessments. In hypoxia ischaemia, the primary cause of encephalopathy, alterations in EEG patterns correlate with. injury severity and evolution. As HIE evolves, causing secondary neuronal death, EEG can track injury progression, informing neuroprotective strategies, seizure management and prognosis. Despite its value, challenges with interpretation and lack of on site expertise has limited its broader adoption. Technological advances, particularly in digital EEG and machine learning, are enhancing real-time analysis. This will allow EEG to expand its role in HIE diagnosis, management and outcome prediction.

High Effectiveness of Midazolam and Lidocaine in the Treatment of Acute Neonatal Seizures

PURPOSE

To assess the clinical effectiveness of treating acute seizures with midazolam and lidocaine infusion.

METHODS

This single-center historical cohort study included 39 term neonates with electrographic seizures who underwent treatment with midazolam (1st line) and lidocaine (2nd line). Therapeutic response was measured using continuous video-EEG monitoring. The EEG measurements included total s eizure burden (minutes), maximum ictal fraction (minutes/hour), and EEG-background (normal/slightly abnormal vs. abnormal). Treatment response was considered good (seizure control with midazolam infusion), intermediate (need to add lidocaine to the control), or no response. Using clinical assessments supplemented by BSID-III and/or ASQ-3 at 2 to 9 years old age, neurodevelopment was classified as normal, borderline, or abnormal.

RESULTS

A good therapeutic response was obtained in 24 neonates, an intermediate response in 15, and no response in any of the neonates. Babies with good response showed lower values in maximum ictal fraction compared with those with intermediate response (95% CI: 5.85-8.64 vs. 9.14-19.14, P = 0.002). Neurodevelopment was considered normal in 24 children, borderline in five, and abnormal in other 10 children. Abnormal neurodevelopment was significantly associated with an abnormal EEG background, maximum ictal fraction >11 minutes, and total s eizure burden >25 minutes (odds ratio 95% CI: 4.74-1708.52, P = 0.003; 1.72-200, P = 0.016; 1.72-142.86, P = 0.026, respectively) but not with the therapeutic response. Serious adverse effects were not recorded.

CONCLUSIONS

This retrospective study suggests that the midazolam/lidocaine association could potentially be efficacious in decreasing seizure burden in term neonates with acute seizures. These results would justify testing the midazolam/lidocaine combination as a first-line treatment for neonatal seizures in future clinical trials.

A method for AI assisted human interpretation of neonatal EEG

The study proposes a novel method to empower healthcare professionals to interact and leverage AI decision support in an intuitive manner using auditory senses. The method’s suitability is assessed through acoustic detection of the presence of neonatal seizures in electroencephalography (EEG). Neurophysiologists use EEG recordings to identify seizures visually. However, neurophysiological expertise is expensive and not available 24/7, even in tertiary hospitals. Other neonatal and pediatric medical professionals (nurses, doctors, etc.) can make erroneous interpretations of highly complex EEG signals. While artificial intelligence (AI) has been widely used to provide objective decision support for EEG analysis, AI decisions are not always explainable. This work developed a solution to combine AI algorithms with a human-centric intuitive EEG interpretation method. Specifically, EEG is converted to sound using an AI-driven attention mechanism. The perceptual characteristics of seizure events can be heard using this method, and an hour of EEG can be analysed in five seconds. A survey that has been conducted among targeted end-users on a publicly available dataset has demonstrated that not only does it drastically reduce the burden of reviewing the EEG data, but also the obtained accuracy is on par with experienced neurophysiologists trained to interpret neonatal EEG. It is also shown that the proposed communion of a medical professional and AI outperforms AI alone by empowering the human with little or no experience to leverage AI attention mechanisms to enhance the perceptual characteristics of seizure events.

aEEG vs cEEG's sensivity for seizure detection in the setting of neonatal intensive care units: A systematic review and meta-analysis

AIM

Amplitude-integrated electroencephalography (aEEG)'s accuracy compared to conventional electroencephalography (cEEG) has not been fully established. The aim of our study was to conduct a systematic review on the sensitivity of the aEEG for neonatal seizure detection.

METHODS

Studies from PubMed and Google Scholar databases comparing recordings of cEEG and aEEG in newborns were included according to the PRISMA method. A quality assessment using the QUADAS-2 tool was provided. A random-effect model was used to account for different sources of variations among studies. Publication biases were represented by a funnel plot, and funnel plot symmetry was assessed.

RESULTS

Fourteen studies were reported; sensitivity of each diagnostic tool used (single-channel aEEG, two-channel aEEG, two-channel aEEG plus raw trace EEG) was compared to that of the gold-standard cEEG and to those of the other methods used. Overall sensitivity of the aEEG ranged from 31.25% to 90%.

CONCLUSION

Our study provides evidence that sensitivity of aEEG varies significantly and that seizure detection rate is lower than that of cEEG. The two-channel aEEG with raw trace EEG shows a high sensitivity and might represent a valid alternative to the cEEG in the setting of neonatal intensive care units (NICUs).

Effect of Treatment of Clinical Seizures vs Electrographic Seizures in Full-Term and Near-Term Neonates: A Randomized Clinical Trial

IMPORTANCE

Seizures in the neonatal period are associated with increased mortality and morbidity. Bedside amplitude-integrated electroencephalography (aEEG) has facilitated the detection of electrographic seizures; however, whether these seizures should be treated remains uncertain.

OBJECTIVE

To determine if the active management of electrographic and clinical seizures in encephalopathic term or near-term neonates improves survival free of severe disability at 2 years of age compared with only treating clinically detected seizures.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial was conducted in tertiary newborn intensive care units recruited from 2012 to 2016 and followed up until 2 years of age. Participants included neonates with encephalopathy at 35 weeks' gestation or more and younger than 48 hours old. Data analysis was completed in April 2021.

INTERVENTIONS

Randomization was to an electrographic seizure group (ESG) in which seizures detected on aEEG were treated in addition to clinical seizures or a clinical seizure group (CSG) in which only seizures detected clinically were treated.

MAIN OUTCOMES AND MEASURES

Primary outcome was death or severe disability at 2 years, defined as scores in any developmental domain more than 2 SD below the Australian mean assessed with Bayley Scales of Neonate and Toddler Development, 3rd ed (BSID-III), or the presence of cerebral palsy, blindness, or deafness. Secondary outcomes included magnetic resonance imaging brain injury score at 5 to 14 days, time to full suck feeds, and individual domain scores on BSID-III at 2 years.

RESULTS

Of 212 randomized neonates, the mean (SD) gestational age was 39.2 (1.7) weeks and 122 (58%) were male; 152 (72%) had moderate to severe hypoxic-ischemic encephalopathy (HIE) and 147 (84%) had electrographic seizures. A total of 86 neonates were included in the ESG group and 86 were included in the CSG group. Ten of 86 (9%) neonates in the ESG and 4 of 86 (4%) in the CSG died before the 2-year assessment. The odds of the primary outcome were not significantly different in the ESG group compared with the CSG group (ESG, 38 of 86 [44%] vs CSG, 27 of 86 [31%]; odds ratio [OR], 1.83; 95% CI, 0.96 to 3.49; P = .14). There was also no significant difference in those with HIE (OR, 1.77; 95% CI, 0.84 to 3.73; P = .26). There was evidence that cognitive outcomes were worse in the ESG (mean [SD] scores, ESG: 97.4 [17.7] vs CSG: 103.8 [17.3]; mean difference, -6.5 [95% CI, -1.2 to -11.8]; P = .01). There was little evidence of a difference in secondary outcomes, including time to suck feeds, seizure burden, or brain injury score.

CONCLUSIONS AND RELEVANCE

Treating electrographic and clinical seizures with currently used anticonvulsants did not significantly reduce the rate of death or disability at 2 years in a heterogeneous group of neonates with seizures.

TRIAL REGISTRATION

http://anzctr.org.au Identifier: ACTRN12611000327987.

Utility of Quantitative EEG for Seizure Detection in Adults

SUMMARY

Traditional review of EEG for seizure detection requires time and the expertise of a trained neurophysiologist; therefore, it is time- and resource-intensive. Quantitative EEG (qEEG) encompasses a variety of methods to make EEG review more efficient and allows for nonexpert review. Literature supports that qEEG is commonly used by neurophysiologists and nonexperts in clinical practice. In this review, the different types of qEEG trends and spectrograms used for seizure detection in adults, from basic concepts to clinical applications, are discussed. The merits and drawbacks of the most common qEEG trends are detailed. The authors detail the retrospective literature on qEEG sensitivity, specificity, and false alarm rate as interpreted by experts and nonexperts alike. Finally, the authors discuss the future of qEEG as a useful screening tool and speculate on the trajectory of future investigations in the field.

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

OBJECTIVE

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

DESIGN AND PATIENTS

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

SETTING

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSION

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

aEEG as a useful tool for neuromonitoring in critically ill children - Current evidence and knowledge gaps

AIM

Amplitude-integrated electroencephalography (aEEG) is used in children beyond neonatal age, but systematic investigations have been lacking. This mini-review summarised aEEG studies on children aged one month to 18 years, evaluated the usefulness of aEEG and identified knowledge gaps or limitations.

METHODS

We searched the PubMed database for articles published in English up to September 2020, and 23 papers were identified.

RESULTS

aEEG was frequently used to compensate for the absence of continuous full-channel EEG monitoring, particularly for detecting seizures. Interpreting background patterns was based on neonatal classifications, as reference values for older infants and children are lacking. It is possible that aEEG could predict outcomes after paediatric cardiac arrests and other conditions. Gaps in our knowledge exist with regard to normal values in healthy children and the effects of sedation on aEEG background patterns in children.

CONCLUSION

The main application of aEEG was detecting and treating paediatric seizures. Further research should determine reference values and investigate the potential to predict outcome after critical events or in acute neurological disease. It is likely that aEEG will play a role in paediatric critical care in the future.

Multichannel EEG abnormalities during the first 6 hours in infants with mild hypoxic-ischaemic encephalopathy

BACKGROUND

Infants with mild HIE are at risk of significant disability at follow-up. In the pre-therapeutic hypothermia (TH) era, electroencephalography (EEG) within 6 hours of birth was most predictive of outcome. This study aims to identify and describe features of early EEG and heart rate variability (HRV) (<6 hours of age) in infants with mild HIE compared to healthy term infants.

METHODS

Infants >36 weeks with mild HIE, not undergoing TH, with EEG before 6 hours of age were identified from 4 prospective cohort studies conducted in the Cork University Maternity Services, Ireland (2003-2019). Control infants were taken from a contemporaneous study examining brain activity in healthy term infants. EEGs were qualitatively analysed by two neonatal neurophysiologists and quantitatively assessed using multiple features of amplitude, spectral shape and inter-hemispheric connectivity. Quantitative features of HRV were assessed in both the groups.

RESULTS

Fifty-eight infants with mild HIE and sixteen healthy term infants were included. Seventy-two percent of infants with mild HIE had at least one abnormal EEG feature on qualitative analysis and quantitative EEG analysis revealed significant differences in spectral features between the two groups. HRV analysis did not differentiate between the groups.

CONCLUSIONS

Qualitative and quantitative analysis of the EEG before 6 hours of age identified abnormal EEG features in mild HIE, which could aid in the objective identification of cases for future TH trials in mild HIE.

IMPACT

Infants with mild HIE currently do not meet selection criteria for TH yet may be at risk of significant disability at follow-up. In the pre-TH era, EEG within 6 hours of birth was most predictive of outcome; however, TH has delayed this predictive value. 72% of infants with mild HIE had at least one abnormal EEG feature in the first 6 hours on qualitative assessment. Quantitative EEG analysis revealed significant differences in spectral features between infants with mild HIE and healthy term infants. Quantitative EEG features may aid in the objective identification of cases for future TH trials in mild HIE.

A Trial of Real-Time Electrographic Seizure Detection by Neuro-ICU Nurses Using a Panel of Quantitative EEG Trends

BACKGROUND

Non-convulsive seizures (NCS) are a common occurrence in the neurologic intensive care unit (Neuro-ICU) and are associated with worse outcomes. Continuous electroencephalogram (cEEG) monitoring is necessary for the detection of NCS; however, delays in interpretation are a barrier to early treatment. Quantitative EEG (qEEG) calculates a time-compressed simplified visual display from raw EEG data. This study aims to evaluate the performance of Neuro-ICU nurses utilizing bedside, real-time qEEG interpretation for detecting recurrent NCS.

METHODS

This is a prospective, single-institution study of patients admitted to the Duke Neuro-ICU between 2016 and 2018 who had NCS identified on traditional cEEG review. The accuracy of recurrent seizure detection on hourly qEEG review by bedside Neuro-ICU nurses was compared to the gold standard of cEEG interpretation by two board-certified neurophysiologists. The nurses first received brief qEEG training, individualized for their specific patient. The bedside qEEG display consisted of rhythmicity spectrogram (left and right hemispheres) and amplitude-integrated EEG (left and right hemispheres) in 1-h epochs.

RESULTS

Twenty patients were included and 174 1-h qEEG blocks were analyzed. Forty-seven blocks contained seizures (27%). The sensitivity was 85.1% (95% CI 71.1-93.1%), and the specificity was 89.8% (82.8-94.2%) for the detection of seizures for each 1-h block when compared to interpretation of conventional cEEG by two neurophysiologists. The false positive rate was 0.1/h. Hemispheric seizures (> 4 unilateral EEG electrodes) were more likely to be correctly identified by nurses on qEEG than focal seizures (≤ 4 unilateral electrodes) (p = 0.03).

CONCLUSIONS

After tailored training sessions, Neuro-ICU nurses demonstrated a good sensitivity for the interpretation of bedside real-time qEEG for the detection of recurrent NCS with a low false positive rate. qEEG is a promising tool that may be used by non-neurophysiologists and may lead to earlier detection of NCS.

Implementation and Early Evaluation of a Quantitative Electroencephalography Program for Seizure Detection in the PICU

OBJECTIVES

To describe implementation and early evaluation of using quantitative electroencephalography for electrographic seizure detection by PICU clinician staff.

DESIGN

Prospective observational study of electrographic seizure detection by PICU clinicians in patients monitored with quantitative electroencephalography. Quantitative electroencephalography program implementation included a continuous education and training package. Continuous quantitative electroencephalography monitoring consisted of two-channel amplitude-integrated electroencephalography, color density spectral array, and raw-electroencephalography.

SETTING

PICU.

PATIENTS

Children less than 18 years old admitted to the PICU during the 14-month study period and deemed at risk of electrographic seizure.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Real time electrographic seizure detection by a PICU team was analyzed for diagnostic accuracy and promptness, against electrographic seizure identification by a trained neurophysiologist, retrospectively reading the same quantitative electroencephalography and blinded to patient details. One-hundred one of 1,510 consecutive admissions (6.7%) during the study period underwent quantitative electroencephalography monitoring. Status epilepticus (35%) and suspected hypoxic-ischemic injury (32%) were the most common indications for quantitative electroencephalography. Electrographic seizure was diagnosed by the neurophysiologist in 12% (n = 12) of the cohort. PICU clinicians correctly diagnosed all 12 patients (100% sensitivity and negative predictive value). An additional eleven patients had a false-positive diagnosis of electrographic seizure (false-positive rate = 52% [31-73%]) leading to a specificity of 88% (79-94%). Median time to detect seizures was 25 minutes (5-218 min). Delayed recognition of electrographic seizure (> 1 hr from onset) occurred in five patients (5/12, 42%).

CONCLUSIONS

Early evaluation of quantitative electroencephalography program to detect electrographic seizure by PICU clinicians suggested good sensitivity for electrographic seizure detection. However, the high false-positive rate is a challenge. Ongoing work is needed to reduce the false positive diagnoses and avoid electrographic seizure detection delays. A comprehensive training program and regular refresher updates for clinical staff are key components of the program.

Combined vEEG and Cerebral Oximetry Results to Determine the Severity of Hypoxic–Ischemic Encephalopathy

The objectives of the study were to evaluate the prognostic utility of bedside monitoring tools for hypoxic–ischemic encephalopathy (HIE) outcome and develop a prognostic predictive model. This retrospective study reviewed neonatal HIE treated with hypothermia between 2013 and 2016. Continuous video electroencephalography (vEEG) recordings scored for background electrocerebral activity, seizure, and sleep–wake cycles, and rSO2 data were stratified by magnetic resonance imaging (MRI) severity. The vEEG and rSO2 were combined in a predictive model. The analysis included 38 patients. The rSO2 was significantly higher in the severe group. vEEG showed early and persistent maximal suppression in the severe group. The predictive correlation of the rSO2 improves when combined with the vEEG.

Amplitude-integrated electroencephalography for neonatal seizure detection. An electrophysiological point of view

Seizures in the newborn are associated with high morbidity and mortality, making their detection and treatment critical. Seizure activity in neonates is often clinically obscured, such that detection of seizures is particularly challenging. Amplitude-integrated EEG is a technique for simplified EEG monitoring that has found an increasing clinical application in neonatal intensive care. Its main value lies in the relative simplicity of interpretation, allowing nonspecialist members of the care team to engage in real-time detection of electrographic seizures. Nevertheless, to avoiding misdiagnosing rhythmic artifacts as seizures, it is necessary to recognize the electrophysiological ictal pattern in the conventional EEG trace available in current devices. The aim of this paper is to discuss the electrophysiological basis of the differentiation of epileptic seizures and extracranial artifacts to avoid misdiagnosis with amplitude-integrated EEG devices.

A Comparison Of Conventional Electroencephalography With Amplitude-Integrated EEG In Detection Of Neonatal Seizures

Introduction

Amplitude-integrated electroencephalogram (aEEG) is widely used in Neonatal Intensive Care Units (NICUs) to monitor neonatal seizures. This method is still not well established compared to conventional electroencephalogram (cEEG), the diagnostic gold standard. However, aEEG can be a good screening tool for the diagnosis of seizures in infants. Our aim in this review study is to evaluate aEEG diagnostic accuracy in comparison with cEEG, for detection of neonatal seizures.

Methods

In this work, we studied the published articles which used EEG and aEEG in the evaluation process of seizures in neonates and compared these techniques to obtain an approach for the detection of neonatal seizures.

Results

Seventeen articles were included. Using aEEG with raw trace to detect individual seizures showed median sensitivity of 78% (range: 68-85) and median specificity of 78% (range: 71-84). The median sensitivity and specificity were 54% (range: 25-95) and 81% (range: 50-100), respectively, in case of using aEEG without raw traces. Brief duration seizures and those occurring away from aEEG leads were less detected.

Conclusion

Studies showed that aEEG has variable sensitivity and specificity. Based on the evidences, aEEG cannot be recommended as the only way for diagnosis and management of seizures in neonates; however, it could complete the diagnosis of seizures in the infant and could be a very good tool for screening seizures.

EEG for the assessment of neurological function in newborn infants immediately after birth

OBJECTIVE

To assess the neurological function of newborn infants in the first minutes after birth using EEG.

DESIGN AND PATIENTS

We obtained electroencephalography (EEG) recordings in term infants following elective caesarean section. After delivery, disposable EEG electrodes were attached to the infants' scalp over the frontal and central regions bilaterally and EEG was recorded for 10 min. Both visual and quantitative measures were used to analyse the EEGs.

SETTING

The operative delivery theatre of Cork University Maternity Hospital, Ireland.

RESULTS

Forty-nine infants had EEG recordings over the frontal and central regions. The median (IQR) age at time of initial EEG recording was 3.0 (2.5-3.8) min. While movement artefact contaminated parts of many recordings, good-quality EEG, with mixed-frequency activity with a range of 25-50 μV, was observed in all infants. The majority of EEG spectral power was within the delta band: the median (IQR) relative delta power was 87.8% (83.7%-90%). Almost all (95%) spectral power was below a median (IQR) of 7.56 Hz (6.17-9.76 Hz).

CONCLUSIONS

EEG recording is very feasible in the immediate newborn period. This study provides valuable objective information about neurological function during this transitional period.

Amplitude-integrated EEG in infants with neonatal abstinence syndrome

BACKGROUND

To describe amplitude-integrated encephalogram (aEEG) characteristics of neonates with neonatal abstinence syndrome (NAS).

METHODS

This is a prospective observational study. Newborns exposed to prenatal opioids and their gestational matched controls were included. A single-channel aEEG was obtained using Olympic 6000 CFM monitor. The background activity (continuous/discontinuous), the amplitudes (μV) and the presence of sleep-wake cycle (SWC) were documented.

RESULTS

A total of 59 infants, 23 with NAS and 36 controls were enrolled. All aEEG were completed within 48 hours of life prior to initiation of treatment. Birth weight and gestational age were similar in both groups. An aEEG was abnormal (discontinuous pattern and/or absent SWC) in 78 % (18/23) of infants with NAS versus only 25% in control group (9/36), [OR 10.8, CI (2.7-46.5) P < 0.001]. 61% of infants with NAS had discontinuous pattern [OR 7.8, CI (2-32) P = 0.001] and 39% had absence of sleep-wake cycle [OR 7.1, CI (1.4-39.4) P = 0.007].

CONCLUSIONS

A majority of infants with NAS have abnormal aEEG activity.

Combined Conventional and Amplitude-Integrated EEG Monitoring in Neonates: A Prospective Study

BACKGROUND/OBJECTIVE

Seizure monitoring via amplitude-integrated EEG is standard of care in many neonatal intensive care units; however, conventional EEG is the gold standard for seizure detection. We compared the diagnostic yield of amplitude-integrated EEG interpreted at the bedside, amplitude-integrated EEG interpreted by an expert, and conventional EEG.

METHODS

Neonates requiring seizure monitoring received amplitude-integrated EEG and conventional EEG in parallel. Clinical events and amplitude-integrated EEG were interpreted at bedside. Subsequently, amplitude-integrated EEG and conventional EEG were independently analyzed by experienced neonatology and neurology readers. Sensitivity and specificity of bedside amplitude-integrated EEG as compared to expert amplitude-integrated EEG interpretation and conventional EEG were evaluated.

RESULTS

Thirteen neonates were monitored for an average duration of 33 hours (range 15-94, SD 25). Fourteen seizure-like events were detected by clinical observation, and 12 others by bedside amplitude-integrated EEG analysis. One of the clinical, and none of the bedside amplitude-integrated EEG events were confirmed as seizures on conventional EEG. Post hoc expert amplitude-integrated EEG interpretation revealed eight suspected seizures, all different from the ones detected by the bedside amplitude-integrated EEG team, of which one was confirmed via conventional EEG. Eight seizures were recorded on conventional EEG. Expert amplitude-integrated EEG interpretation had a sensitivity of 13% with 46% specificity for individual seizure detection, and a sensitivity of 50% with 46% specificity for detecting patients with seizures.

CONCLUSION

Real-world bedside amplitude-integrated EEG monitoring failed to detect all seizures evidenced via conventional EEG, while misclassifying other events as seizures. Even post hoc expert amplitude-integrated EEG interpretation provided limited sensitivity and specificity. Considering the poor sensitivity and specificity of bedside amplitude-integrated EEG interpretation, combined monitoring may provide limited clinical benefit.

Amplitude-integrated EEG use in neonatal abstinence syndrome: a pilot study

Objective: Though central nervous system irritability is a well-established consequence of neonatal drug withdrawal, brain function in infants with neonatal abstinence syndrome (NAS) is not well understood. Amplitude-integrated electroencephalography (aEEG) is a bedside tool used for monitoring brain activity and seizures. We describe the prevalence of abnormal aEEG background patterns in infants with NAS.Methods: In this pilot, observational study primary outcomes were aEEG findings, Finnegan scores, and length of hospital stay in NAS patients. Subjects underwent an initial aEEG and a repeat study following pharmacologic treatment. Two independent reviewers analyzed aEEGs post discharge.Results: Six out of nine infants had abnormal aEEGs demonstrating lack of sleep-wake cycling (SWC) (50%), discontinuity (41.7%), and low voltage (8.3%). Seizures were not detected. NAS scores were lower for infants with continuous aEEGs versus those whose aEEGs were not continuous (5.83 versus 9.17; p = .054). Length of stay was 7.8 ± 4.4 days in infants with continuous aEEGs versus 26 ± 10.5 days in infants without continuous aEEGs (p = .003).Conclusions: Infants exposed to opioids in utero are at increased risk for discontinuity and abnormal SWC detectable on aEEG. Infants with abnormal aEEGs are more likely to have higher NAS scores, require pharmacologic treatment and have longer lengths of stay.

Diagnosis of seizures and encephalopathy using conventional EEG and amplitude integrated EEG

Seizures are more common in the neonatal period than at any other time of life, partly due to the relative hyperexcitability of the neonatal brain. Brain monitoring of sick neonates in the NICU using either conventional electroencephalography or amplitude integrated EEG is essential to accurately detect seizures. Treatment of seizures is important, as evidence increasingly indicates that seizures damage the brain in addition to that caused by the underlying etiology. Prompt treatment has been shown to reduce seizure burden with the potential to ameliorate seizure-mediated damage. Neonatal encephalopathy most commonly caused by a hypoxia-ischemia results in an alteration of mental status and problems such as seizures, hypotonia, apnea, and feeding difficulties. Confirmation of encephalopathy with EEG monitoring can act as an important adjunct to other investigations and the clinical examination, particularly when considering treatment strategies such as therapeutic hypothermia. Brain monitoring also provides useful early prognostic indicators to clinicians. Recent use of machine learning in algorithms to continuously monitor the neonatal EEG, detect seizures, and grade encephalopathy offers the exciting prospect of real-time decision support in the NICU in the very near future.

Timing and modes of death after pediatric out-of-hospital cardiac arrest resuscitation

AIM

To determine the timing and modes of death of children admitted to a pediatric critical care unit (PICU) of a tertiary care center after an out-of-hospital cardiac arrest (OHCA).

METHODS

This is a retrospective descriptive study at a tertiary care PICU of all consecutive patients <18 years old who received ≥1 min of chest compressions, had return of spontaneous circulation (ROSC) for ≥20 min, and were admitted to the PICU after an OHCA. Modes of death were classified as brain death (BD), withdrawal due to neurologic prognosis (W/D-neuro), withdrawal for refractory circulatory failure (W/D-RCF), and re-arrest without ROSC (RA).

RESULTS

191 consecutive patients were admitted to the PICU from February 2005 to May 2013 after an OHCA. Eighty-six(45%) patients died prior to discharge: BD in 47%(40/86), W/D-neuro in 34%(29/86), W/D-RCF in 10%(9/86), and RA in 9%(8/86). Time to death was longer for patients with W/D-neuro: 4 days [1, 5] and BD 4 days [1, 5](p < 0.01) as opposed to those with W/D-RCF (1 day[1, 2]) and RA(1 day[0.5, 1]). Of patients who underwent W/D-neuro, 9/29(31%) died within 3 days of PICU admission and 20/29(69%) ≥3 days. Of patients who died after W/D-neuro, 12/29(41%) received therapeutic hypothermia, 27/29(93%) underwent EEG monitoring, 21/29(72%) had a brain CT, and 13/29(45%) had a brain MRI. All MRIs showed signs of hypoxic-ischemic injury.

CONCLUSION

Neurologic injury was the most common mode of death post-resuscitation care OHCA after in a tertiary care center PICU. Neurologic prognostication impacts the outcome of a large proportion of patients after OHCA, and further studies are warranted to improve its reliability.

Amplitude-integrated electroencephalography for seizure detection in newborn infants

The amplitude-integrated electroencephalogram (aEEG) is a filtered and compressed EEG trend that can be used for long-term monitoring of brain function in patients of all ages. aEEG is increasingly used in neonatal intensive care units since several studies have shown its utility in high-risk newborn infants. Main indications for aEEG monitoring include early evaluation of brain function after perinatal asphyxia and seizure detection. The aEEG is usually recorded from one or two channels derived from parietal, central, or frontal leads. Although the aEEG is very useful for identifying high-risk infants and infants with seizures, the compressed trend has limitations with regards to detection of individual seizures. However, modern monitors also display the corresponding EEG (aEEG/EEG), which increases the probability of detecting single brief seizures. For improved evaluation of electrocortical brain activity the aEEG/EEG should be assessed together with repeated conventional EEGs or multi-channel EEG monitoring in a multi-disciplinary team.

Electroencephalographic monitoring for seizure identification and prognosis in term neonates

Seizures represent a manifestation of neurological disease in the neonatal period. Historically, neonatal seizures were identified by direct clinical observation. However, since most seizures are electroencephalographic (EEG)-only (subclinical, non-convulsive) and clinical manifestations may be subtle, many clinicians place increasing importance on EEG data including conventional EEG or amplitude-integrated EEG to identify seizures in neonates. Beyond seizure identification, the EEG is a robust source of information about brain function that can be useful for neurobehavioral prognostication in some neonates. This review summarizes the available data regarding EEG for neonatal seizure diagnosis and brain function assessment.

EEG findings and outcomes of continuous video-EEG monitoring started prior to initiation of seizure treatment in the perinatal stroke

BACKGROUND

To analyze the findings in the background EEG activity of infants who suffered perinatal stroke.

METHODS

Eleven neonates born 2009-2014 diagnosed of ischemic stroke by MRI (three of them with multistroke) underwent continuous video-EEG monitoring. Visual and spectral (power spectrum and coherence) analyses of the background EEG was performed in three moments: 1) Onset of EEG recording (prior to initiate seizure treatment), 2) Post-ictal epoch (1-2 h after the last seizure), and 3) one-two days after seizure control. All children aged 2-6 years underwent neurodevelopmental assessment.

RESULTS

Discontinuity, asymmetry, asynchrony, transients, and relative power spectrum in δ and θ frequency bands increased significantly (p < 0.05) in the post-ictal epoch with respect to onset of EEG recording. After seizure control, discontinuity, asynchrony, and θ power spectrum no longer had significant differences with those found at onset of EEG recording. Significant differences between the ischemic and unaffected hemispheres were found in transients and in β coherence (p = 0.002; p = 0.001, respectively) exclusively in the post-ictal epoch. Seizure burden and time-to-control ranged 5-38 min and 0.5-40 h respectively. Currently, only one child is affected by spastic monoparesis. The intelligence quotients ranged 96-123.

CONCLUSIONS

The background EEG can undergo significant changes in the post-ictal epoch due to the seizure activity triggered by the perinatal stroke. Most of these EEG changes involve all brain activity and not exclusively the ischemic hemisphere. Many of these modifications in the EEG background reverse following the seizure control. Video-EEG monitoring allows accurate/immediate diagnosis and rapid/intensive treatment of the stroke-associated seizures.

Visual and Quantitative Electroencephalographic Analysis in Healthy Term Neonates Within the First Six Hours and the Third Day of Life

BACKGROUND

What constitutes a "normal" background electroencephalography (EEG) rhythm immediately after birth is not well understood. We performed video-electroencephalography recordings in the first six hours (first measure) and the third day of life (second measure) for evidence of transient changes in brain function.

METHODS

We performed a cohort study of an incidental sample of healthy term neonates in a single-center nursery. Main outcome measures were as follows: (1) EEG visual analysis, which included sleep-wake cycles, proportions of discontinuity and bursts with delta brushes, and number per hour of alpha/theta rolandic activity, encoches frontales, and transients; and (2) the electroencephalographic spectral analysis, which included power spectrum in the following frequency bands: delta, 0.5 to 4 Hz; theta, 4 to 8 Hz; alpha, 8 to 13 Hz; and beta, 13 to 30 Hz. Theta/delta and alpha/delta ratios were also calculated.

RESULTS

Twenty-two babies were enrolled. Significant findings (P < 0.05) in the first six hours with respect to 48 to 72 hours of life were (1) increased discontinuity, indeterminate sleep, and bursts with delta brushes; (2) higher number of transients, and lower number of alpha/theta rolandic activity and encoches frontales. Minimal changes were found in power spectrum data. However, using receiver operating characteristic curve analysis, theta/delta ratio ≤0.484 was the best cutoff to discriminate between the two measures (positive predictive value, 100.0; 95% confidence interval 71.0 to 100).

CONCLUSIONS

In healthy term neonates, immature electroencephalographic patterns, lack of clearly defined sleep-wake cycles, and frequent transients can be considered normal electroencephalographic findings in the first six hours of life. Normative power spectrum data are provided. These findings suggest that neonatal adaptation immediately after birth leads to transient changes in brain function.

Electrographic Seizures during the Early Postnatal Period in Preterm Infants

OBJECTIVE

To investigate the frequency and characteristics of electrographic seizures in preterm infants in the early postnatal period.

STUDY DESIGN

Infants <32 weeks gestational age (GA) (n = 120) were enrolled for continuous multichannel electroencephalography (EEG) recording initiated as soon as possible after birth and continued for approximately up to 72 hours of age. Electrographic seizures were identified visually, annotated, and analyzed. Quantitative descriptors of the temporal evolution of seizures, including total seizure burden, seizure duration, and maximum seizure burden, were calculated.

RESULTS

Median GA was 28.9 weeks (IQR, 26.6-30.3 weeks) and median birth weight was 1125 g (IQR, 848-1440 g). Six infants (5%; 95% CI, 1.9-10.6%) had electrographic seizures. Median total seizure burden, seizure duration, and maximum seizure burden were 40.3 minutes (IQR, 5.0-117.5 minutes), 49.6 seconds (IQR, 43.4-76.6 seconds), and 10.8 minutes/hour (IQR, 1.6-20.2 minutes/hour), respectively. Seizure burden was highest in 2 infants with significant abnormalities on neuroimaging.

CONCLUSION

Electrographic seizures are infrequent within the first few days of birth in very preterm infants. Seizures in this population are difficult to detect accurately without continuous multichannel EEG monitoring.

Seizures in Preterm Neonates: A Multicenter Observational Cohort Study

BACKGROUND

The purpose of this study was to characterize seizures among preterm neonates enrolled in the Neonatal Seizure Registry, a prospective cohort of consecutive neonates with seizures at seven pediatric centers that follow the American Clinical Neurophysiology Society's neonatal electroencephalography monitoring guideline.

STUDY DESIGN

Of 611 enrolled neonates with seizures, 92 (15%) were born preterm. Seizure characteristics were evaluated by gestational age at birth for extremely preterm (<28 weeks, N = 18), very preterm (28 to <32 weeks, N = 18), and moderate to late preterm (32 to <37 weeks, N = 56) and compared with term neonates.

RESULTS

Hypoxic-ischemic encephalopathy (33%) and intracranial hemorrhage (27%) accounted for the etiology in more than half of preterm neonates. Hypothermia therapy was utilized in 15 moderate to late preterm subjects with encephalopathy. The presence of subclinical seizures, monotherapy treatment failure, and distribution of seizure burden (including status epilepticus) was similar in preterm and term neonates. However, exclusively subclinical seizures occurred more often in preterm than term neonates (24% vs 14%). Phenobarbital was the most common initial medication for all gestational age groups, and failure to respond to an initial loading dose was 63% in both preterm and term neonates. Mortality was similar among the three preterm gestational age groups; however, preterm mortality was more than twice that of term infants (35% vs 15%).

CONCLUSIONS

Subclinical seizures were more common and mortality was higher for preterm than term neonates. These data underscore the importance of electroencephalographic monitoring and the potential for improved management in preterm neonates.

Seizure Detection by Critical Care Providers Using Amplitude-Integrated Electroencephalography and Color Density Spectral Array in Pediatric Cardiac Arrest Patients

OBJECTIVES

Determine the accuracy and confidence of critical care medicine providers to identify seizures using amplitude-integrated electroencephalography versus amplitude-integrated electroencephalography combined with color density spectral array electroencephalography (aEEG + CDSA).

DESIGN

Tutorial and questionnaire.

SETTING

PICU.

SUBJECTS

Pediatric critical care providers (attendings, fellows, and nurses).

INTERVENTIONS

A standardized powerpoint tutorial on amplitude-integrated electroencephalography and color density spectral array followed by classification of 100 amplitude-integrated electroencephalography images and 100 amplitude-integrated electroencephalography combined with color density spectral array as displaying seizures or not displaying seizures.

MEASUREMENTS AND MAIN RESULTS

Electroencephalography tracings were obtained from children monitored with continuous electroencephalography after cardiac arrest. The gold standard for seizure identification was continuous electroencephalography interpretation by a pediatric electroencephalographer. The same electroencephalography tracings were used to generate images containing only amplitude-integrated electroencephalography or aEEG + CDSA. Twenty-three critical care medicine providers underwent a 30-minute tutorial on amplitude-integrated electroencephalography and color density spectral array interpretation. They were then asked to determine if there were seizures on 100 amplitude-integrated electroencephalography images and 100 aEEG + CDSA. Amplitude-integrated electroencephalography seizure detection sensitivity was 77% (95% CI, 73%-80%), specificity of 65% (95% CI, 62%-67%), negative predictive value of 88% (95% CI, 86%-90%), and positive predictive value of 46% (95% CI, 43%-49%). For aEEG + CDSA, sensitivity was 77% (95% CI, 74%-81%), specificity of 68% (95% CI, 66%-71%), negative predictive value of 89% (95% CI, 87%-90%), and positive predictive value of 49% (95% CI, 46%-52%). Sensitivity for status epilepticus detection was 77% (95% CI, 71%-82%) with amplitude-integrated electroencephalography and 75% (95% CI, 69%-81%) with aEEG + CDSA. The addition of color density spectral array to amplitude-integrated electroencephalography did not improve seizure detection. However, 87% of critical care medicine providers qualitatively felt that combining both modalities increased their ability to detect seizures.

CONCLUSIONS

Amplitude-integrated electroencephalography and aEEG + CDSA offer reasonable sensitivity and negative predictive value for seizure detection by critical care medicine providers. aEEG + CDSA did not improve seizure detection over amplitude-integrated electroencephalography alone although critical care medicine providers felt more confident using both tools combined. Amplitude-integrated electroencephalography and color density spectral array require further evaluation as a tool for screening for seizures and should only be used in conjunction with professional continuous electroencephalography review.

Utilization of Quantitative EEG Trends for Critical Care Continuous EEG Monitoring: A Survey of Neurophysiologists

PURPOSE

Quantitative EEG (QEEG) can be used to assist with review of large amounts of data generated by critical care continuous EEG monitoring. This study aimed to identify current practices regarding the use of QEEG in critical care continuous EEG monitoring of critical care patients.

METHODS

An online survey was sent to 796 members of the American Clinical Neurophysiology Society (ACNS), instructing only neurophysiologists to participate.

RESULTS

The survey was completed by 75 neurophysiologists that use QEEG in their practice. Survey respondents reported that neurophysiologists and neurophysiology fellows are most likely to serve as QEEG readers (97% and 52%, respectively). However, 21% of respondents reported nonneurophysiologists are also involved with QEEG interpretation. The majority of nonneurophysiologist QEEG data review is aimed to alert neurophysiologists to periods of concern, but 22% reported that nonneurophysiologists use QEEG to directly guide clinical care. Quantitative EEG was used most frequently for seizure detection (92%) and burst suppression monitoring (59%). A smaller number of respondents use QEEG for monitoring the depth of sedation (29%), ischemia detection (28%), vasospasm detection (28%) and prognosis after cardiac arrest (21%). About half of the respondents do not review every page of the raw critical care continuous EEG record when using QEEG. Respondents prefer a panel of QEEG trends displayed as hemispheric data, when applicable. There is substantial variability regarding QEEG trend preferences for seizure detection and ischemia detection.

CONCLUSIONS

QEEG is being used by neurophysiologists and nonneurophysiologists for applications beyond seizure detection, but practice patterns vary widely. There is a need for standardization of QEEG methods and practices.

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.

Lost in Transition: A Systematic Review of Neonatal Electroencephalography in the Delivery Room-Are We Forgetting an Important Biomarker for Newborn Brain Health?

BACKGROUND

Electroencephalography (EEG) monitoring is routine in neonatal intensive care units (NICUs) for detection of seizures, neurological monitoring of infants following perinatal asphyxia, and increasingly, following preterm delivery. EEG monitoring is not routinely commenced in the delivery room (DR).

OBJECTIVES

To determine the feasibility of recording neonatal EEG in the DR, and to assess its usefulness as a marker of neurological well-being during immediate newborn transition.

METHODS

We performed a systematic stepwise search of PubMed using the following terms: infant, newborns, neonate, DR, afterbirth, transition, and EEG. Only human studies describing EEG monitoring in the first 15 min following delivery were included. Infants of all gestational ages were included.

RESULTS

Two original studies were identified that described EEG monitoring of newborn infants within the DR. Both prospective observational studies used amplitude-integrated EEG (aEEG) monitoring and found it feasible in infants >34 weeks' gestation; however, technical challenges made it difficult to obtain continuous reliable data. Different EEG patterns were identified in uncompromised newborns and those requiring resuscitation.

CONCLUSION

EEG monitoring is possible in the DR and may provide an objective baseline measure of neurological function. Further feasibility studies are required to overcome technical challenges in the DR, but these challenges are not insurmountable with modern technology.

Diagnostic Accuracy of Electrographic Seizure Detection by Neurophysiologists and Non-Neurophysiologists in the Adult ICU Using a Panel of Quantitative EEG Trends

PURPOSE

To evaluate the sensitivity and specificity of a panel of quantitative EEG (qEEG) trends for seizure detection in adult intensive care unit (ICU) patients when reviewed by neurophysiologists and non-neurophysiologists.

METHODS

One hour qEEG panels (n = 180) were collected retrospectively from 45 ICU patients and were distributed to 5 neurophysiologists, 7 EEG technologists, and 5 Neuroscience ICU nurses for evaluation of seizures. Each panel consisted of the following qEEG tools, displayed separately for left and right hemisphere electrodes: rhythmicity spectrogram (rhythmic run detection and display; Persyst Inc), color density spectral array, EEG asymmetry index, and amplitude integrated EEG. The reviewers did not have access to the raw EEG data.

RESULTS

For the reviewer's ability to detect the presence of seizures on qEEG panels when compared with the gold standard of independent raw EEG review, the sensitivities and specificities are as follows: neurophysiologists 0.87 and 0.61, EEG technologists 0.80 and 0.80, and Neuroscience ICU nurses 0.87 and 0.61, respectively. There was no statistical difference among the three groups regarding sensitivity.

CONCLUSIONS

Quantitative EEG display panels are a promising tool to aid detection of seizures by non-neurophysiologists as well as by neurophysiologists. However, even when used as a panel, qEEG trends do not appear to be adequate as the sole method for reviewing continuous EEG data.

Low cerebral activity and cerebral oxygenation during immediate transition in term neonates-A prospective observational study

AIM

To analyze whether in term neonates during immediate transition after birth low cerebral activity measured by amplitude-integrated EEG (aEEG) is linked to cerebral regional oxygen saturation (crSO2) measured by near-infrared spectroscopy (NIRS). Additionally, the cerebral fractional tissue oxygen extraction (cFTOE) was calculated to analyze whether cerebral activity is linked to cFTOE.

METHODS

A total of 244 term neonates delivered by primary cesarean section were studied. In addition to routine monitoring with pulse oximetry, aEEG and NIRS measurements were performed during the first 15min after birth. The mean minimum (Vmin) and maximum (Vmax) amplitude of the cerebral activity as well as crSO2 and cFTOE for each minute was determined. Neonates with initial Vmin<5μV or Vmax<10μV, which normalized during transition (study group) were compared to neonates with normal aEEG values throughout the whole monitoring period (control group).

RESULTS

9 neonates fulfilled inclusion criteria to the study group and were compared to 50 neonates in the control group. Vmin, Vmax, crSO2, SpO2 and cFTOE were compared from the 4th to 15thmin after birth. During our study period, Vmin and Vmax were significantly lower in the study group than in the control group. crSO2 was significantly lower in the study group until minute 11, dropping below the 10th centile in minute 8. cFTOE was significantly higher in the study group until minute 10, rising above the 90th centile in minutes 8 and 9. SpO2 was within normal ranges in both groups. crSO2 and cFTOE were within normal ranges in the control group.

CONCLUSION

The present study demonstrates that neonates with initially low cerebral activity during immediate transition after birth concurrently showed low crSO2 (<10th percentile), but increased cerebral oxygen extraction (cFTOE>90th percentile). Cerebral monitoring with aEEG and NIRS might provide useful information on the neonates' condition during immediate transition.

Enhanced Monitoring of the Preterm Infant during Stabilization in the Delivery Room

Monitoring of preterm infants in the delivery room (DR) remains limited. Current guidelines suggest that pulse oximetry should be available for all preterm infant deliveries, and that if intubated a colorimetric carbon dioxide detector should provide verification of correct endotracheal tube placement. These two methods of assessment represent the extent of objective monitoring of the newborn commonly performed in the DR. Monitoring non-invasive ventilation effectiveness (either by capnography or respiratory function monitoring) and cerebral oxygenation (near-infrared spectroscopy) is becoming more common within research settings. In this article, we will review the different modalities available for cardiorespiratory and neuromonitoring in the DR and assess the current evidence base on their feasibility, strengths, and limitations during preterm stabilization.

Amplitude-Integrated Electroencephalography Interpretation During Therapeutic Hypothermia: An Educational Program and Novel Teaching Tool

Therapeutic hypothermia (TH) is now considered a standard in tertiary NICUs. Amplitude-integrated electroencephalography (aEEG) is an important adjunct to this therapy and is gaining acceptance for use on the neonatal population. It can be easily incorporated into practice with appropriate education and training. Current publications are lacking regarding nursing care of neonatal patients undergoing th with the use of aEEG. This article presents a broad educational program as well as novel teaching tool for neonatal nurses caring for this population.

Amplitude-integrated EEG for detection of neonatal seizures: a systematic review

PURPOSE

Amplitude-integrated electroencephalogram (aEEG) is being used increasingly for monitoring seizures in neonatal units. Its accuracy, compared with "the gold-standard" conventional elecroencephalogram (cEEG) is still not well established. We aimed to conduct a systematic review to evaluate the diagnostic accuracy of aEEG when compared with cEEG, for detection of neonatal seizures.

METHOD

A systematic review was conducted using the Cochrane methodology. EMBASE, CINAHL and PubMed databases were searched in September 2014. Studies comparing simultaneous recordings of cEEG and aEEG for detection of seizures in neonatal population were included. QUADAS 2 tool was used to examine "risk of bias" and "applicability".

RESULTS

Ten studies (patient sample 433) were included. Risk of bias was high in five studies, unclear in one and low in four. For the detection of individual seizures, when "aEEG with raw trace" was used, median sensitivity was 76% (range: 71-85), and specificity 85% (range: 39-96). When "aEEG without raw trace" was used, median sensitivity was 39% (range: 25-80) and specificity 95% (range: 50-100). Detailed meta-analysis could not be done because of significant clinical/methodological heterogeneity. Seizure detection was better when interpreted by experienced clinicians. Seizures with low amplitude/brief duration and those occurring away from aEEG leads were less likely to be detected.

CONCLUSION

Studies included in the systematic review showed aEEG to have relatively low and variable sensitivity and specificity. Based on the available evidence, aEEG cannot be recommended as the mainstay for diagnosis and management of neonatal seizures. There is an urgent need of well-designed studies to address this issue definitively.

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.

Neurophysiological aspects of neonatal seizures

Recently, amplitude-integrated EEG (aEEG) has been increasingly used and proved useful in neonatal intensive care units (NICU) for the management of neonatal seizures. It does not replace, but is supplementary to standard EEG. This article reviews some of findings obtained with standard EEGs, and tries to interpret them with recent findings in the field of basic science. Seizures mainly occur in active-REM sleep in neonates. This is in sharp contrast to those in older children and adults, in whom epileptic seizures occur mainly in NREM sleep. This may be explained by neurotransmitter effects on sleep mechanisms of the neonatal brain that are different from those of older individuals. When all clinical seizures have no electrical correlates, they are non-epileptic, but when the correlation between clinical seizures and frequent electrical discharges are inconsistent, they should rather be considered epileptic, reflecting progression of status epilepticus causing electro-clinical dissociation. Electro-clinical dissociation is not a characteristic of neonatal seizures per se, but a feature of prolonged status epilepticus in adults as well as children. It occurs when prolonged status epilepticus itself causes a progressively severe encephalopathy, or when status occurs in the presence of a severe underlying encephalopathy. In neonates without pre-existing brain damage, frequent seizures per se may cause mild depression characterized by the loss of high voltage slow patterns, an important constituent of slow wave sleep reflecting cortico-cortical connectivity. Mild depression only in the acute stage is not associated with neurological sequelae, but previously damaged brain may be more vulnerable than normal brain.

Amplitude-integrated electro-encephalography: the child neurologist's perspective

Neurologists increasingly recognize that critically ill patients are at high risk for seizures, particularly nonconvulsive seizures, and that neuromonitoring is a useful tool for diagnosing seizures and assessing brain function in these patients. Amplitude-integrated electroencephalography (EEG) is a simplified bedside neurophysiology tool that has become widely used in neonates over the past decade. Despite widespread interest by both neurologists and neonatologists in continuous brain monitoring, amplitude-integrated EEG has been largely ignored by neurologists, forcing neonatologists to "go it alone" when interpreting data from this bedside tool. Although amplitude-integrated EEG cannot replace conventional EEG for background monitoring and detection of seizures, it remains a useful instrument that complements conventional EEG, is being widely adopted by neonatologists, and should be supported by neonatal neurologists.

Electroencephalographic monitoring in the pediatric intensive care unit

Continuous electroencephalographic (CEEG) monitoring is used with increasing frequency in critically ill children to provide insight into brain function and to identify electrographic seizures. CEEG monitoring use often impacts clinical management, most often by identifying electrographic seizures and status epilepticus. Most electrographic seizures have no clinical correlate, and thus would not be identified without CEEG monitoring. There are increasing data showing that electrographic seizures and electrographic status epilepticus are associated with worse outcome. Seizure identification efficiency may be improved by further development of quantitative electroencephalography trends. This review describes the clinical impact of CEEG data, the epidemiology of electrographic seizures and status epilepticus, the impact of electrographic seizures on outcome, the utility of quantitative electroencephalographic trends for seizure identification, and practical considerations regarding CEEG monitoring.

Neonatal seizures and status epilepticus

Neonatal seizures are common, often require EEG monitoring for diagnosis and management, may be associated with worse neurodevelopmental outcome, and can often be treated with existing anticonvulsants. A neonatal electrographic seizure is defined as a sudden, repetitive, evolving, and stereotyped event of abnormal electrographic pattern with amplitude of at least 2 μV and a minimum duration of 10 seconds. The diagnosis of neonatal seizures relies heavily on the neurophysiologist's interpretation of EEG. Consideration of specific criteria for the definition of a neonatal seizure, including seizure duration, location, morphology, evolution, semiology, and overall seizure burden, has utility for both the clinician and the researcher. The importance of EEG in the diagnosis and management of neonatal seizures, the electrographic characteristics of neonatal seizures, the impact of neonatal seizures on outcome, and tools to aid in the identification of neonatal seizures are reviewed.

aEEG and NIRS during transition and resuscitation after birth: promising additional tools; an observational study

AIM OF THE STUDY

During resuscitation no routine cerebral monitoring is available. We aimed at monitoring cerebral activity and oxygenation continuously during neonatal transition and resuscitation.

METHODS

Neonates ≥34 weeks of gestation born via cesarean section were included. Cerebral activity was continuously measured with amplitude-integrated-EEG (aEEG) and cerebral oxygenation (rSO2) with near-infrared-spectroscopy (NIRS) during the first 10 min after birth. For quantitative analysis of aEEG every minute the mean minimum amplitude (V(min)) and maximum amplitude (V(max)) was determined. Uncompromised neonates were compared to neonates in need of resuscitation.

RESULTS

Out of 224 eligible neonates 31 uncompromised and 15 in need of respiratory support were included. Uncompromised neonates showed higher values for V(min) in the third minute and higher values for V(max) in the third and fourth minute compared to the tenth minute post-partum. In uncompromised neonates rSO2 values during the first 6 min after birth were lower compared to minute ten. Neonates in need of respiratory support had lower rSO2 values over the first 8 min after birth compared to minute ten.

CONCLUSIONS

This is the first study demonstrating that monitoring of aEEG and NIRS to measure cerebral activity and oxygenation during immediate postpartum transition is feasible. During transition compromised neonates requiring resuscitation showed a different cerebral activity pattern compared to uncompromised neonates.

Neurodiagnostic techniques in neonatal critical care

This article reviews recent advances in the neurodiagnostic tools available to clinicians practicing in neonatal critical care. The advent of induced mild hypothermia for acute neonatal hypoxic-ischemic encephalopathy in 2005 has been responsible for renewed urgency in the development of precise and reliable neonatal neurodiagnostic techniques. Traditional evaluations of bedside head ultrasounds, head computed tomography scans, and routine electroencephalograms (EEGs) have been upgraded in most tertiary pediatric centers to incorporate protocols for MRI, continuous EEG monitoring with remote bedside access, amplitude-integrated EEG, and near-infrared spectroscopy. Meanwhile, recent studies supporting the association between placental pathology and neonatal brain injury highlight the need for closer examination of the placenta in the neurodiagnostic evaluation of the acutely ill newborn. As the pursuit of more effective neuroprotection moves into the "hypothermia plus" era, the identification, evaluation, and treatment of the neurologically affected newborn in the neonatal intensive care unit has increasing significance.

Diagnostic value of amplitude-integrated electroencephalogram in neonatal seizures

OBJECTIVE To investigate the accuracy of amplitude-integrated electroencephalography (aEEG) in detecting full-term neonatal seizures. METHODS Conventional EEG (cEEG) and aEEG were simultaneously applied to 62 full-term newborns with seizures and results were analyzed with different methods. RESULTS Of 876 seizures confirmed by cEEG, 21% were detected by clinical observation, 44.4% by aEEG and 85.7% by aEEG plus C3/C4 raw EEG. Of 531 seizures with a frequency higher than 5 times/h, 52.5% were detected by aEEG and 96.8% by aEEG plus C3/C4 raw EEG. Of 510 seizures lasting longer than 60 s, 50.6% were diagnosed by aEEG and 84.1% by aEEG plus C3/C4 raw EEG. Of 509 seizures originating in the central region, 57.9% were detected by aEEG and 90.9% by aEEG plus C3/C4 raw EEG. CONCLUSION Combination of aEEG with cEEG offers more accurate diagnosis, especially for detecting high-frequency, long-lasting and central region-generated seizures.