Amplitude-integrated electroencephalography and brain injury in infants undergoing Norwood-type operations

Quantitative Electroencephalography for Predication of Neurological Dysfunction in Type A Aortic Dissection: A Prospective Observational Study

BACKGROUND

Type A aortic dissection presents challenges with postoperative cerebral complications, and this study evaluates the predictive value of quantitative electroencephalography for perioperative brain function prognosis.

METHODS AND RESULTS

Amplitude-integrated electroencephalography (aEEG) processes raw signals through filtering, amplitude integration, and time compression, displaying the data in a semilogarithmic format. Using this method, postoperative relative band power (post-RBP) α% and dynamic aEEG (ΔaEEG) grade were significantly associated with neurological dysfunction in univariate and multivariable analyses, with area under the receiver operating characteristic curve of 0.876 (95% CI, 0.825-0.926) for the combined model. Postoperative relative band power α% and ΔaEEG were significantly associated with adverse outcomes, with area under the receiver operating characteristic curve of 0.903 (95% CI, 0.835-0.971) for the combined model. Postoperative relative band power α% and ΔaEEG were significantly associated with transient neurological dysfunction and stroke, with areas under the receiver operating characteristic curve of 0.818 (95% CI, 0.760-0.876) and 0.868 (95% CI, 0.810-0.926) for transient neurological dysfunction, and 0.815 (95% CI, 0.743-0.886) and 0.831 (95% CI, 0.746-0.916) for stroke. Among 56 patients, the Alberta Stroke Program Early Computed Tomography score was superior to ΔaEEG in predicting neurological outcomes (area under the receiver operating characteristic curve of 0.872 versus 0.708 [95% CI, 0.633-0.783]; P<0.05).

CONCLUSIONS

Perioperative quantitative electroencephalography monitoring offers valuable insights into brain function changes in patients with type A aortic dissection. ∆aEEG grades can aid in early detection of adverse outcomes, while postoperative relative band power and ∆aEEG grades predict transient neurological dysfunction. Quantitative electroencephalography can assist cardiac surgeons in assessing brain function and improving outcomes in patients with type A aortic dissection.

REGISTRATION

URL: https://www.chictr.org.cn; Unique identifier: ChiCTR2200055980.

Neuromonitoring practices for neonates with congenital heart disease: a scoping review

Neonates with congenital heart disease (CHD) are at risk for adverse neurodevelopmental outcomes. This scoping review summarizes neuromonitoring methods in neonates with CHD. We identified 84 studies investigating the use of near-infrared spectroscopy (NIRS) (n = 37), electroencephalography (EEG) (n = 20), amplitude-integrated electroencephalography (aEEG) (n = 10), transcranial Doppler sonography (TCD) (n = 6), and multimodal monitoring (n = 11). NIRS was used to evaluate cerebral oxygenation, identify risk thresholds and adverse events in the intensive care unit (ICU), and outcomes. EEG was utilized to screen for seizures and to predict adverse outcomes. Studies of aEEG have focused on characterizing background patterns, detecting seizures, and outcomes. Studies of TCD have focused on correlation with short-term clinical outcomes. Multimodal monitoring studies characterized cerebral physiologic dynamics. Most of the studies were performed in single centers, had a limited number of neonates (range 3-183), demonstrated variability in neuromonitoring practices, and lacked standardized approaches to neurodevelopmental testing. We identified areas of improvement for future research: (1) large multicenter studies to evaluate developmental correlates of neuromonitoring practices; (2) guidelines to standardize neurodevelopmental testing methodologies; (3) research to address geographic variation in resource utilization; (4) integration and synchronization of multimodal monitoring; and (5) research to establish a standardized framework for neuromonitoring techniques across diverse settings. IMPACT: This scoping review summarizes the literature regarding neuromonitoring practices in neonates with congenital heart disease (CHD). The identification of low cerebral oxygenation thresholds with NIRS may be used to identify neonates at risk for adverse events in the ICU or adverse neurodevelopmental outcomes. Postoperative neuromonitoring with continuous EEG screening for subclinical seizures and status epilepticus, allow for early and appropriate therapy. Future studies should focus on enrolling larger multicenter cohorts of neonates with CHD with a standardized framework of neuromonitoring practices in this population. Postoperative neurodevelopmental testing should utilize standard assessments and testing intervals.

Postoperative EEG abnormalities in relation to neurodevelopmental outcomes after pediatric cardiac surgery

BACKGROUND

We had reported that postoperative EEG background including sleep-wake cycle (SWC) and discharge (seizures, spikes/sharp waves) abnormalities were significantly correlated with adverse early outcomes in children after cardiac surgery. We aimed to analyze the relations between these EEG abnormalities and neurodevelopmental outcomes at about 2 years after cardiac surgery.

METHODS

We enrolled 121 patients undergoing cardiac surgery at 3.3 months (0.03 ~ 28 months). EEG abnormalities described above during the first postoperative 48 h were evaluated. Griffiths Mental Development Scales-Chinese was used to evaluate the quotients of overall development and 5 subscales of the child's locomotor, language, personal-social, eye-hand coordination and performance skills at 16 ~ 31 months of age.

RESULTS

EEG background abnormalities occurred in 59/121 (48.8%) patients and 33 (55.9%) unrecovered to normal by 48 h. Abnormal SWC occurred in 15 (12.4%) patients and 7 (5.8%) unrecovered to normal by 48 h. EEG seizures occurred in 11 (9.1%) patients with frontal lobe seizures in 4. Spikes/sharp waves occurred in 100 (82.6%). EEG background abnormalities, number of spikes/sharp waves and frontal lobe seizures were significantly associated with neurodevelopmental impairment at about 1 ~ 2 year after surgery (Ps ≤ 0.05).

CONCLUSIONS

Most parameters of EEG abnormalities were significantly associated with neurodevelopmental impairment after cardiac surgery.

IMPACT

Neurodevelopmental impairment in children with congenital heart disease remain poorly understood. Previous studies had reported that either EEG seizures or background abnormalities were associated with worse neurodevelopmental outcomes. Our present study showed that all the EEG background and discharge abnormalities including EEG background, seizures and spikes/sharp waves in the early postoperative period were significantly associated with neurodevelopmental impairment at about 1 ~ 2 years after cardiac surgery. Comprehensive evaluation of early postoperative EEG may provide further insights about postoperative brain injury, its relation with neurodevelopmental impairment, and guide to improve clinical management.

Neonatal seizures during extra corporeal membrane oxygenation support

To evaluate EEG monitoring during neonatal ECMO and to identify any correlations between seizure detection to abnormal neuroimaging. Eight-year, service evaluation of neonates who received at least one continuous EEG (cEEG) whilst on ECMO at Great Ormond Street Hospital. Pearson's chi-square test and multivariate logistic regression analysis were used to assess clinical and EEG variables association with seizures and neuroimaging findings. Fifty-seven neonates were studied; 57 cEEG recordings were reviewed. The incidence of seizures was 33% (19/57); of these 74% (14/19) were electrographic-only. The incidence of status epilepticus was 42%, (8/19 with 6 neonates having electrographic-only status and 2 electro-clinical status. Seizures were detected within an hour of recording in 84%, (16/19). The overall mortality rate was 39% (22/57). Seizure detection was strongly associated with female gender (OR 4.8, 95% CI: 1.1-20.4, p = 0.03), abnormal EEG background activity (OR 2.8, 95% CI: 1.1-7.4, p = 0.03) and abnormal EEG focal features (OR 23.6, 95% CI: 5.4-103.9, p = 0.001). There was a strong association between the presence of seizures and abnormal neuroimaging findings (OR 10.9, 95% CI: 2.8-41.9, p = 0.001). Neonates were highly likely to have abnormal neuroimaging findings in the presence of severely abnormal background EEG (OR 9.5, 95% CI 1.7-52.02, p = 0.01) and focal EEG abnormalities (OR 6.35, 95% CI 1.97-20.5, p = 0.002)Conclusion: The study highlights the importance of cEEG in neonates undergoing ECMO. An association between seizure detection and abnormal neuroimaging findings was described. What is Known: • Patients on ECMO are at a higher risk of seiures. • Continuous EEG monitoring is recommended by the ACNS for high risk and ECMO patients. What is New: • In this cohort, neonates with sezirues were 11 times more likely of having abnromal neuroimaging findings. • Neonates with burst suppressed or suppressed EEG background were 9.5 times more likely to have abnormal neuroimaging findings. What does this study add? • This study reports a 33% incidence of neonatal seizures during ECMO. • Neonates with seizures were 11 times more likely to have an abnormal brain scan. • The study captures the real-time approach of EEG monitoring. • Recommended cEEG monitoring should last at least 24 h for ECMO patients. • This is the first study to assess this in neonates only.

Continuous Electroencephalogram (cEEG) Findings and Neurodevelopmental Outcomes in Neonates with Congenital Heart Disease (CHD) at 12-24 Months of Age

OBJECTIVE

This study aims to assess the role of continuous EEG (cEEG) background patterns and duration of cross-clamp time and cardiopulmonary bypass (CPB) in children with congenital heart disease (CHD) undergoing cardiac surgery and its correlation with abnormal neurodevelopmental outcomes at 12-24 months on Bayley Scales of Infant and Toddler Development (BSID-III).

METHODS

This retrospective cohort study included infants with CHD and cEEG monitoring, who underwent surgery by 44 weeks gestational age.

RESULTS

34 patients were included, who were operated at median age - 7 days. Longer duration of cross- camp time was associated with poor language composite scores (LCS) (p value = 0.036). A significant association existed between severity of encephalopathy in 24-hour post-operative period and poor LCS (p value = 0.026).

CONCLUSION

Majority of neonates with CHD have below average cognitive, language and motor composite scores on BSID-III. Longer duration of cross-clamp time and severity of encephalopathy during 24-hour post-operative EEG monitoring are associated with poor LCS.

Neurological injury in pediatric heart disease: A review of developmental and acquired risk factors and management considerations

Medical and surgical advancements have improved survival in children with acquired and congenital heart disease (CHD), but the burden of neurological morbidity is high. Brain disorders associated with CHD include white matter injury, stroke, seizure, and neurodevelopmental delays. While genetics and disease-specific factors play a substantial role in early brain injury, therapeutic management of the heart disease intensifies the risk. There is a growing interest in understanding how to reduce brain injury and improve neurodevelopmental outcomes in cardiac diseases. Pediatric neurologists serve a vital role in care teams managing these complex patients, providing interpretation of neuromonitoring and imaging, managing neurologic emergencies, assisting with neuro prognostication, and identifying future research aims.

Neurological Impact of Slower Rewarming during Bypass Surgery in Infants

BACKGROUND

 Hypothermia is a neuroprotective strategy during cardiopulmonary bypass. Rewarming entailing a rapid rise in cerebral metabolism might lead to secondary neurological sequelae. In this pilot study, we aimed to validate the hypothesis that a slower rewarming rate would lower the risk of cerebral hypoxia and seizures in infants.

METHODS

 This is a prospective, clinical, single-center study. Infants undergoing cardiac surgery in hypothermia were rewarmed either according to the standard (+1°C in < 5 minutes) or a slow (+1°C in > 5-8 minutes) rewarming strategy. We monitored electrocortical activity via amplitude-integrated electroencephalography (aEEG) and cerebral oxygenation by near-infrared spectroscopy during and after surgery.

RESULTS

 Fifteen children in the standard rewarming group (age: 13 days [5-251]) were cooled down to 26.6°C (17.2-29.8) and compared with 17 children in the slow-rewarming group (age: 9 days [4-365]) with a minimal temperature of 25.7°C (20.1-31.4). All neonates in both groups (n = 19) exhibited suppressed patterns compared with 28% of the infants > 28 days (p < 0.05). During rewarming, only 26% of the children in the slow-rewarming group revealed suppressed aEEG traces (vs. 41%; p = 0.28). Cerebral oxygenation increased by a median of 3.5% in the slow-rewarming group versus 1.5% in the standard group (p = 0.9). Our slow-rewarming group revealed no aEEG evidence of any postoperative seizures (0 vs. 20%).

CONCLUSION

 These results might indicate that a slower rewarming rate after hypothermia causes less suppression of electrocortical activity and higher cerebral oxygenation during rewarming, which may imply a reduced risk of postoperative seizures.

Neuroimaging and Neurodevelopmental Outcomes Among Individuals With Complex Congenital Heart Disease: JACC State-of-the-Art Review

Although neuroimaging advances have deepened our understanding of brain health in individuals with congenital heart disease (CHD), it is less clear how neuroimaging findings relate to neurodevelopmental and mental health outcomes across the lifespan. We systematically synthesized and critically evaluated evidence on associations between neuroimaging and neurodevelopmental, neurocognitive, psychiatric, or behavioral outcomes among individuals with transposition of great arteries or single-ventricle CHD (Protocol CRD42021229617). Six databases were searched and 45 papers from 25 unique studies were identified. Structural brain injury was generally linked to poorer neurodevelopment in infancy. Brain volumes and microstructural and functional brain changes appear linked to neurocognitive outcomes, including deficits in attention, learning, memory, and executive function in children and adolescents. Fetal neuroimaging studies were limited. Four papers investigated psychiatric outcomes; none found associations with neuroimaging. Multicenter, longitudinal studies incorporating functional neuroimaging and mental health outcomes are much-needed to inform early neuroprotective and therapeutic strategies in CHD.

Continuous Amplitude-Integrated Electroencephalography During Neonatal and Pediatric Extracorporeal Membrane Oxygenation

PURPOSE

Early prognostication of neurologic outcome in neonates and children supported with extra-corporeal membrane oxygenation (ECMO) is challenging. Amplitude-integrated EEG (aEEG) offers the advantages of continuous monitoring and 24-hours availability at the bedside for intensive care unit providers. The objective of this study was to describe the early electrophysiological background patterns of neonates and children undergoing ECMO and their association with neurologic outcomes.

METHODS

This was a retrospective review of neonates and children undergoing ECMO and monitored with aEEG. Amplitude-integrated EEG was summarized as an aEEG background score determined within the first 24 hours of ECMO and divided in 3-hour periods. Screening for electrical seizures was performed throughout the full ECMO duration. Neurologic outcome was defined by the Pediatric Cerebral Performance Category score at hospital discharge.

RESULTS

Seventy-three patients (median age 79 days [8-660], median weight 4.78 kg [3.24-10.02]) were included in the analysis. Thirty-two patients had a favorable neurologic outcome and 41 had an unfavorable neurologic outcome group at hospital discharge. A 24-hour aEEG background score >17 was associated with an unfavorable outcome with a sensitivity of 44%, a specificity of 97%, a positive predictive value of 95%, and a negative predictive value of 57%. In multivariate analysis, 24-hour aEEG background score was associated with unfavorable outcome (hazard ratio, 6.1; p = 0.001; 95% confidence interval, 2.31-16.24). The presence of seizures was not associated with neurologic outcome at hospital discharge.

CONCLUSIONS

Continuous aEEG provides accurate neurologic prognostication in neonates and children supported with ECMO. Early aEEG monitoring may help intensive care unit providers to guide clinical care and family counseling.

Continuous electroencephalography (cEEG) in infants with congenital heart disease (CHD)

BACKGROUND

Neonates with congenital heart disease (CHD) undergoing cardiopulmonary bypass (CPB) surgery have increased risk of impaired neurodevelopmental outcomes secondary to brain injury. This study aims to characterize pre- and post-operative continuous EEG (cEEG) patterns to detect abnormal cerebral activity in infants with CHD and investigate whether an association exists between the degree of encephalopathy in pre- and post-operative cEEG.

METHODS

This retrospective cohort study conducted between 2010 and 2018 at a tertiary hospital in Cleveland, OH included infants with CHD with cEEG monitoring, who underwent CPB surgery within first 6 months of life.

RESULTS

Study included 77 patients, of which 61% were males who were operated at median age 6 days. Pre-operatively, 69% and 87% had normal cEEG and sleep-wake cycles, respectively. Post-operatively, 80% had abnormal cEEG. Longer circulatory arrest time and CPB were associated with lack of continuity (p 0.011), excessive discontinuity (p 0.007) and prolonged inter-burst interval (IBI) duration (p value < 0.001). A significant association existed between severity of encephalopathy in immediate and 24-h post-operative period (p value < 0.001).

CONCLUSIONS

More than 80% of neonates with CHD have abnormal post-operative EEG. Longer circulatory arrest time and CPB were associated with lack of continuity, excessive discontinuity, and prolonged IBI duration on post-operative EEG.

IMPACT

This study shows that majority of neonates with congenital heart disease (CHD) have normal pre-operative EEG with a continuous background and normal sleep-wake cycles. Also, 80% of neonates had abnormal post-operative EEG. Longer duration of arrest time and bypass time was associated with lack of continuity, excessive discontinuity, and prolonged IBI duration during post-operative EEG monitoring. These findings will help clinicians when counseling parents in the intensive care unit, risk stratification, and long-term neurodevelopmental monitoring in these high-risk patients.

Acute Cardiac Care for Neonatal Heart Disease

This manuscript is one component of a larger series of articles produced by the Neonatal Cardiac Care Collaborative that are published in this supplement of Pediatrics. In this review article, we summarize the contemporary physiologic principles, evaluation, and management of acute care issues for neonates with complex congenital heart disease. A multidisciplinary team of authors was created by the Collaborative's Executive Committee. The authors developed a detailed outline of the manuscript, and small teams of authors were assigned to draft specific sections. The authors reviewed the literature, with a focus on original manuscripts published in the last decade, and drafted preliminary content and recommendations. All authors subsequently reviewed and edited the entire manuscript until a consensus was achieved. Topics addressed include cardiopulmonary interactions, the pathophysiology of and strategies to minimize the development of ventilator-induced low cardiac output syndrome, common postoperative physiologies, perioperative bleeding and coagulation, and common postoperative complications.

Optimizing Neurodevelopmental Outcomes in Neonates With Congenital Heart Disease

Neurodevelopmental impairment is a common and important long-term morbidity among infants with congenital heart disease (CHD). More than half of those with complex CHD will demonstrate some form of neurodevelopmental, neurocognitive, and/or psychosocial dysfunction requiring specialized care and impacting long-term quality of life. Preventing brain injury and treating long-term neurologic sequelae in this high-risk clinical population is imperative for improving neurodevelopmental and psychosocial outcomes. Thus, cardiac neurodevelopmental care is now at the forefront of clinical and research efforts. Initial research primarily focused on neurocritical care and operative strategies to mitigate brain injury. As the field has evolved, investigations have shifted to understanding the prenatal, genetic, and environmental contributions to impaired neurodevelopment. This article summarizes the recent literature detailing the brain abnormalities affecting neurodevelopment in children with CHD, the impact of genetics on neurodevelopmental outcomes, and the best practices for neonatal neurocritical care, focusing on developmental care and parental support as new areas of importance. A framework is also provided for the infrastructure and resources needed to support CHD families across the continuum of care settings.

Protecting brains and saving futures guidelines: A prospective, multicenter, and observational study on the use of telemedicine for neonatal neurocritical care in Brazil

Background

Management of high-risk newborns should involve the use of standardized protocols and training, continuous and specialized brain monitoring with electroencephalography (EEG), amplitude integrated EEG, Near Infrared Spectroscopy, and neuroimaging. Brazil is a large country with disparities in health care assessment and some neonatal intensive care units (NICUs) are not well structured with trained personnel able to provide adequate neurocritical care. To reduce this existing gap, an advanced telemedicine model of neurocritical care called Protecting Brains and Saving Futures (PBSF) Guidelines was developed and implemented in a group of Brazilian NICUs.

Methods

A prospective, multicenter, and observational study will be conducted in all 20 Brazilian NICUs using the PBSF Guidelines as standard-of-care. All infants treated accordingly to the guidelines during Dec 2021 to Nov 2024 will be eligible. Ethical approval was obtained from participating centers. The primary objective is to describe adherence to the PBSF Guidelines and clinical outcomes, by center and over a 3-year period. Adherence will be measured by quantification of neuromonitoring, neuroimaging exams, sub-specialties consultation, and clinical case discussions and videoconference meetings. Clinical outcomes of interest are detection of seizures during hospitalization, use of anticonvulsants, inotropes, and fluid resuscitation, death before hospital discharge, length of hospital stay, and referral of patients to specialized follow-up.

Discussion

The study will provide evaluation of PBSF Guidelines adherence and its impact on clinical outcomes. Thus, data from this large prospective, multicenter, and observational study will help determine whether neonatal neurocritical care via telemedicine can be effective. Ultimately, it may offer the necessary framework for larger scale implementation and development of research projects using remote neuromonitoring.

Trial registration

NCT03786497, Registered 26 December 2018, https://www.clinicaltrials.gov/ct2/show/NCT03786497?term=protecting+brains+and+saving+futures&draw=2&rank=1.

Survival, Morbidities, and Developmental Outcomes among Low Birth Weight Infants with Congenital Heart Defects

OBJECTIVE

Prematurity and low birth weight (LBW) are risk factors for increased morbidity and mortality in infants with congenital heart defects (CHDs). We sought to describe survival, inhospital morbidities, and 2-year neurodevelopmental follow-up in LBW infants with CHD.

STUDY DESIGN

We included infants with birth weight (BW) <2,500 g diagnosed with CHD (except isolated patent ductus arteriosus) admitted January 2013 to March 2016 to a single level-IV academic neonatal intensive care unit. We reported CHD prevalence by BW and gestational age; selected in-hospital morbidities and mortality by infant BW, CHD type, and surgical intervention; and developmental outcomes by Bayley's scales of infant and toddler development, third edition (BSID-III) scores at age 2 years.

RESULTS

Among 420 infants with CHD, 28 (7%) underwent cardiac surgery. Median (25th and 75th percentiles) gestational age was 30 (range: 27-33) weeks and BW was 1,258 (range: 870-1,853) g. There were 134 of 420 (32%) extremely LBW (<1,000 g) infants, 82 of 420 (20%) were small for gestational age, and 51 of 420 (12%) multiples. Most common diagnosis: atrial septal defect (260/420, 62%), followed by congenital anomaly of the pulmonary valve (75/420, 18%). Most common surgical procedure: pulmonary artery banding (5/28, 18%), followed by the tetralogy of Fallot corrective repair (4/28, 14%). Survival to discharge was 88% overall and lower among extremely LBW (<1,000 g, 81%) infants and infants undergoing surgery (79%). Comorbidities were common (35%); retinopathy of prematurity and bronchopulmonary dysplasia were most prevalent. BSID-III scores were available on 148 of 176 (84%); any scores <85 were noted in 73 of 148 (49%), with language being most commonly affected.

CONCLUSION

Among LBW infants with congenital heart disease, hospital mortality varied by BW and cardiac diagnosis.

KEY POINTS

· In low birth weight infants with congenital heart disease, survival varied by birth weight and cardiac diagnosis.. · Overall survival was higher than previously reported.. · There were fewer morbidities than previously reported.. · Bayley's scale-III scores at 2 years of age were <85 for nearly half..

Evaluation of Seizure Risk in Infants After Cardiopulmonary Bypass in the Absence of Deep Hypothermic Cardiac Arrest

Background

Guidelines recommend evaluation for electrographic seizures in neonates and children at risk, including after cardiopulmonary bypass (CPB). Although initial research using screening electroencephalograms (EEGs) in infants after CPB found a 21% seizure incidence, more recent work reports seizure incidences ranging 3–12%. Deep hypothermic cardiac arrest was associated with increased seizure risk in prior reports but is uncommon at our institution and less widely used in contemporary practice. This study seeks to establish the incidence of seizures among infants following CPB in the absence of deep hypothermic cardiac arrest and to identify additional risk factors for seizures via a prediction model.

Methods

A retrospective chart review was completed of all consecutive infants ≤ 3 months who received screening EEG following CPB at a single center within a 2-year period during 2017–2019. Clinical and laboratory data were collected from the perioperative period. A prediction model for seizure risk was fit using a random forest algorithm, and receiver operator characteristics were assessed to classify predictions. Fisher’s exact test and the logrank test were used to evaluate associations between clinical outcomes and EEG seizures.

Results

A total of 112 infants were included. Seizure incidence was 10.7%. Median time to first seizure was 28.1 h (interquartile range 18.9–32.2 h). The most important factors in predicting seizure risk from the random forest analysis included postoperative neuromuscular blockade, prematurity, delayed sternal closure, bypass time, and critical illness preoperatively. When variables captured during the EEG recording were included, abnormal postoperative neuroimaging and peak lactate were also highly predictive. Overall model accuracy was 90.2%; accounting for class imbalance, the model had excellent sensitivity and specificity (1.00 and 0.89, respectively).

Conclusions

Seizure incidence was similar to recent estimates even in the absence of deep hypothermic cardiac arrest. By employing random forest analysis, we were able to identify novel risk factors for postoperative seizure in this population and generate a robust model of seizure risk. Further work to validate our model in an external population is needed.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-021-01313-1.

Effect of perioperative amplitude-integrated electroencephalography on neurodevelopmental outcomes following infant heart surgery

The purpose of the current study was to determine the effect of perioperative amplitude-integrated electroencephalography (aEEG) on neurodevelopmental outcomes in infants with congenital heart disease (CHD). A total of 93 children with CHD were included in the current study. All patients enrolled in the present study had undergone cardiac surgery prior to 3 months of age and pre- or postoperative aEEG was monitored. Participants were assessed after 1 year using the Bayley Scales of Infant Test. A total of 82.2% of infants exhibited continuous normal voltage preoperatively (CNV) and 93.7% exhibited CNV postoperatively. Seizures were indicated in 2 infants preoperatively and 3 infants postoperatively. Compared with infants with PDI, infants with cyanotic CHD (β=17.218) exhibited a significantly lower MDI, an increased length of intensive care stay, and lower PDI scores (β=-0.577). Infants that underwent surgery with CPB exhibited higher PDI scores (β=11.956). Infants that exhibited behavioral problems also had lower PDI scores (β=-10.605). An abnormal preoperative background pattern and an absent postoperative SWC independently predicted poorer motor (P=0.014) and cognitive (P=0.049) outcomes at 1 year. The current study demonstrated that infants with CHD who underwent cardiac surgery prior to 3 months of age exhibited delayed neurodevelopmental outcomes, and that an aEEG assessment can aid in predicting these outcomes following surgery.

The Congenital Heart Disease Brain: Prenatal Considerations for Perioperative Neurocritical Care

Altered brain development has been highlighted as an important contributor to adverse neurodevelopmental outcomes in children with congenital heart disease. Abnormalities begin prenatally and include micro- and macrostructural disturbances that lead to an altered trajectory of brain growth throughout gestation. Recent progress in fetal imaging has improved understanding of the neurobiological mechanisms and risk factors for impaired fetal brain development. The impact of the prenatal environment on postnatal neurological care has also gained increased focus. This review summarizes current data on the timing and pattern of altered prenatal brain development in congenital heart disease, the potential mechanisms of these abnormalities, and the association with perioperative neurological complications.

Intraoperative Cortical Asynchrony Predicts Abnormal Postoperative Electroencephalogram

BACKGROUND

Postoperative electroencephalograms (EEGs) can identify seizure activity and neurologic dysfunction in high-risk neonates requiring cardiac surgical procedures. Although intraoperative EEG monitoring is uncommon, variations in cerebral blood flow and temperature during antegrade cerebral perfusion (ACP) can manifest as cortical asynchrony during EEG monitoring. We hypothesized that intraoperative EEG cortical asynchrony would identify neonates at risk for abnormal postoperative EEG tracings.

METHODS

Neonates requiring ACP for cardiac repair or palliation had continuous baseline, intraoperative, and postoperative hemodynamic and EEG monitoring. Synchronous and asynchronous cortical bursts were quantified during (1) cooling before ACP, (2) ACP, and (3) rewarming. Asynchronous bursts were defined as interhemispheric variations in electrical voltage or frequency. Neonates were divided into 2 groups, those with and without an abnormal postoperative EEG, which was defined as either persistent asynchrony for more than 2 hours or seizure activity on EEG.

RESULTS

Among 40 neonates, 296 asynchronous bursts were noted, most commonly during rewarming. Eight (20%) neonates had an abnormal postoperative EEG (seizure activity, n = 3; persistent asynchrony, n = 5). Baseline demographics and intraoperative hemodynamics were similar between the groups. However, the total number of intraoperative asynchronous bursts was greater in neonates with an abnormal postoperative EEG (17 [11, IQR:24] vs 3 [IQR:1, 7]; P < .001). Multivariate analysis confirmed that the number of asynchronous bursts was independently associated with an abnormal postoperative EEG (odds ratio,1.35; confidence interval,:1.10, 1.65; P = .004).

CONCLUSIONS

Neonates with a greater number of intraoperative asynchronous cortical bursts had an abnormal postoperative EEG.

MHCA with SACP versus DHCA in Pediatric Aortic Arch Surgery: A Comparative Study

The safety and efficacy of selective antegrade cerebral perfusion (SACP) in children undergoing aortic arch surgery are unclear. In this retrospective analysis, we compared moderate hypothermic circulatory arrest (MHCA; n = 61) plus SACP vs deep hypothermic circulatory arrest (DHCA; n = 53) in children undergoing aortic arch surgery during a period from January 2008 to December 2017. Demographic characteristics and the underlying anomalies were comparable between the two groups. The MHCA + SACP group had shorter cardiopulmonary bypass (CPB) time (146.9 ± 40.6 vs 189.6 ± 41.2 min for DHCA; p < 0.05) and higher nasopharyngeal temperature (26.0 ± 2.1 vs 18.9 ± 1.6 °C; p < 0.01). The MHCA + SACP group had lower rate of neurologic complications (3/61 vs 10/53 for DHCA; p < 0.05) but not complications in other organ systems. The MHCA + SACP group also had less 24-hour chest drainage (median, interquartile rage: 28.9, 12.6–150.0 vs 47.4, 15.2–145.0 ml/kg for DHCA; p < 0.05), shorter duration of postoperative mechanical ventilation (35.0, 15.4–80.3 vs 94.0, 42.0–144.0 h; p < 0.01), and shorter stay in intensive care unit (3.9, 3.0–7.0 vs 7.7, 5.0–15.0 d; p < 0.05). In regression analysis, in-hospital mortality was associated with longer CPB time. In conclusion, MHCA + SACP is associated with better short-term outcomes in children receiving aortic arch surgery under CPB.

Neurodevelopmental outcome of children with congenital heart disease

Congenital heart disease (CHD) constitutes the most common congenital malformation, with moderate or severe CHD occurring in around 6 in 1000 live births. Due to advances in medical care, survival rates have increased significantly. Thus, the majority of children with CHD survive until adolescence and adulthood. Children with CHD requiring cardiopulmonary bypass surgery are at risk for neurodevelopmental impairments in various domains, including mild impairments in cognitive and neuromotor functions, difficulties with social interaction, inattention, emotional symptoms, and impaired executive function. The prevalence for these impairments ranges from 20% to 60% depending on age and domain ("high prevalence-low severity"). Domains are often affected simultaneously, leading to school problems with the need for learning support and special interventions. The etiology of neurodevelopmental impairments is complex, consisting of a combination of delayed intrauterine brain development and newly occurring perioperative brain injuries. Mechanisms include altered intrauterine hemodynamic flow as well as neonatal hypoxia and reduced cerebral blood flow. The surgical procedure and postoperative phase add to this cascade of factors interfering with normal brain development. Early identification of children at high risk through structured follow-up programs is mandated to provide individually tailored early interventions and counseling to improve developmental health.

Electroencephalographic Response to Deep Hypothermic Circulatory Arrest in Neonatal Swine and Humans

BACKGROUND

Piglets are used to study neurologic effects of deep hypothermic circulatory arrest (DHCA), but no studies have compared human and swine electroencephalogram (EEG) responses to DHCA. The importance of isoelectricity before circulatory arrest is not fully known in neonates. We compared the EEG response to DHCA in human neonates and piglets.

METHODS

We recorded 2 channel, left and right centroparietal, subdermal EEG in 10 neonatal patients undergoing operations involving DHCA and 10 neonatal piglets that were placed on cardiopulmonary bypass and underwent a simulated procedure using DHCA. EEG waveforms were analyzed for the presence and extent of burst suppression and isoelectricity by automated moving window analysis. The patients were monitored with 16-channel array EEG for 48 hours postoperatively and underwent postoperative brain magnetic resonance imaging.

RESULTS

After induction of anesthesia, humans and piglets both displayed slowing or brief suppression, then mild burst suppression, and then severe burst suppression during cooling. All piglets subsequently achieved isoelectricity at 22.4° ± 6.9°C, whereas only 1 human did at 20.2°C. Piglets and humans emerged from severe, mild, and then brief suppression patterns during rewarming. Among the patients, there were no seizures during postoperative monitoring and 1 instance of increased white matter injury on postoperative magnetic resonance imaging.

CONCLUSIONS

Our data suggest that current cooling strategies may not be sufficient to eliminate all EEG activity before circulatory arrest in humans but are sufficient in swine. This important difference between the swine and human response to DHCA should be considered when using this model.

Amplitude-integrated electroencephalography during the first 72 h after birth in neonates diagnosed prenatally with congenital heart disease

BackgroundLittle is known on amplitude-integrated electroencephalography (aEEG) during the first few days after birth in neonates with congenital heart disease (CHD). Our aim was, therefore, to assess electrocortical activity using aEEG within the first 72 h after birth in neonates diagnosed prenatally with CHD, and to define independent prenatal and postnatal predictors for abnormal aEEG.MethodsNeonates with CHD who were admitted to the neonatal intensive care unit between 2010 and 2017 were retrospectively included. We assessed aEEG background patterns, sleep-wake cycling, and epileptic activity during the first 72 h after birth and defined prenatal and postnatal clinical parameters associated with aEEG patterns.ResultsSeventy-two neonates were included. Twenty-six (36%) had mildly abnormal and six (8%) had severely abnormal aEEG background patterns at some point during the study period. Sleep-wake cycling was present in 97% of the neonates. Subclinical seizures were common (15%), whereas none of the neonates had clinical seizures. Only treatment with sedatives was a significant predictor for abnormal aEEG background patterns, explaining 56% of the variance.ConclusionAbnormal aEEG background patterns are common and are strongly associated with treatment with sedatives in neonates with prenatally diagnosed CHD. Future studies should assess the association between early postnatal aEEG abnormalities and neurodevelopmental outcome.

Brain Injury and Neurodevelopmental Outcome in Congenital Heart Disease: A Systematic Review

CONTEXT

Brain injury during prenatal and preoperative postnatal life might play a major role in neurodevelopmental impairment in infants with congenital heart disease (CHD) who require corrective or palliative surgery during infancy. A systematic review of cerebral findings during this period in relation to neurodevelopmental outcome (NDO), however, is lacking.

OBJECTIVE

To assess the association between prenatal and postnatal preoperative cerebral findings and NDO in infants with CHD who require corrective or palliative surgery during infancy.

DATA SOURCES

PubMed, Embase, reference lists.

STUDY SELECTION

We conducted 3 different searches for English literature between 2000 and 2016; 1 for prenatal cerebral findings, 1 for postnatal preoperative cerebral findings, and 1 for the association between brain injury and NDO.

DATA EXTRACTION

Two reviewers independently screened sources and extracted data on cerebral findings and neurodevelopmental outcome. Quality of studies was assessed using the Newcastle-Ottawa Quality Assessment Scale.

RESULTS

Abnormal cerebral findings are common during the prenatal and postnatal preoperative periods. Prenatally, a delay of cerebral development was most common; postnatally, white matter injury, periventricular leukomalacia, and stroke were frequently observed. Abnormal Doppler measurements, brain immaturity, cerebral oxygenation, and abnormal EEG or amplitude-integrated EEG were all associated with NDO.

LIMITATIONS

Observational studies, different types of CHD with different pathophysiological effects, and different reference values.

CONCLUSIONS

Prenatal and postnatal preoperative abnormal cerebral findings might play an important role in neurodevelopmental impairment in infants with CHD. Increased awareness of the vulnerability of the young developing brain of an infant with CHD among caregivers is essential.

Postoperative Amplitude-Integrated Electroencephalography Predicts Four-Year Neurodevelopmental Outcome in Children with Complex Congenital Heart Disease

OBJECTIVES

To evaluate the predictive value of pre- and postoperative amplitude-integrated electroencephalography (aEEG) on neurodevelopmental outcomes in children operated for congenital heart disease (CHD).

STUDY DESIGN

Prospectively enrolled cohort of 60 infants with CHD who underwent cardiac surgery with cardiopulmonary bypass in the first 3 months of life. Infants with a genetic comorbidity were excluded. aEEG was assessed for 12 hours pre- and 48 hours postoperatively. Background pattern was classified by the use of standard categories, and the presence of seizures and sleep-wake cycles (SWCs) was noted. Outcome at 1 and 4 years of age was assessed with standardized developmental tests.

RESULTS

Preoperatively, infants either showed continuous normal voltage (n = 56) or discontinuous normal voltage (n = 4). Postoperatively, abnormal background pattern (flat trace, burst suppression, or continuous low voltage) was detected in 7 (12%), discontinuous normal voltage in 37 (61%), and continuous normal voltage in 16 (27%) infants. Nineteen infants (32%) did not return to normal SWCs within the recording period. Seizures were detected in 4 infants preoperatively and in another 4 postoperatively. After we controlled for surgical and postoperative risk factors, abnormal postoperative background pattern and lack of return to SWCs independently predicted poorer intelligence quotient at 4 years (P = .03 and P = .04 respectively) but was not related to motor outcome.

CONCLUSION

aEEG is a useful bedside tool that helps to predict outcome in infants undergoing open-heart surgery for CHD. Abnormal postoperative background pattern and lack of return to SWCs are markers for subsequent impaired cognitive development.

Evaluation of Preoperative Amplitude-Integrated Electroencephalography (aEEG) Monitoring for Predicting Long-Term Neurodevelopmental Outcome Among Infants Undergoing Major Surgery in the Neonatal Period

The authors aimed to evaluate preoperative amplitude-integrated electroencephalography (aEEG) patterns for predicting neurodevelopmental outcome among infants undergoing major surgery in the neonatal period. They retrospectively reviewed the preoperative aEEG data of 58 neonates who had undergone major neonatal surgery between 2006 and 2008. The authors classified aEEGs using a weighted background score. Neurodevelopmental outcome was assessed at 3 years of age using the Bayley Scales of Toddler and Infant Development III. Over a third of infants (36%) showed an abnormal aEEG background. Seizure activity was identified in 11 (19%) infants. The majority (68%) of infants had developmental delay, with no significant differences between cardiac and other surgery groups. Logistic regression found no statistically significant but some clinically important associations between aEEG background and neurodevelopmental outcome. Comorbidity was associated with worse outcomes. While the predictive utility of aEEG in this population remains unclear, the findings suggest that further research is warranted.

Goal-directed-perfusion in neonatal aortic arch surgery

Reduction of mortality and morbidity in congenital cardiac surgery has always been and remains a major target for the complete team involved. As operative techniques are more and more standardized and refined, surgical risk and associated complication rates have constantly been reduced to an acceptable level but are both still present. Aortic arch surgery in neonates seems to be of particular interest, because perfusion techniques differ widely among institutions and an ideal form of a so called "total body perfusion (TBP)" is somewhat difficult to achieve. Thus concepts of deep hypothermic circulatory arrest (DHCA), regional cerebral perfusion (RCP/with cardioplegic cardiac arrest or on the perfused beating heart) and TBP exist in parallel and all carry an individual risk for organ damage related to perfusion management, chosen core temperature and time on bypass. Patient safety relies more and more on adequate end organ perfusion on cardiopulmonary bypass, especially sensitive organs like the brain, heart, kidney, liver and the gut, whereby on adequate tissue protection, temperature management and oxygen delivery should be visualized and monitored.

Amplitude-integrated EEG in newborns with critical congenital heart disease predicts preoperative brain magnetic resonance imaging findings

OBJECTIVE

The study aims are to evaluate cerebral background patterns using amplitude-integrated electroencephalography in newborns with critical congenital heart disease, determine if amplitude-integrated electroencephalography is predictive of preoperative brain injury, and assess the incidence of preoperative seizures. We hypothesize that amplitude-integrated electroencephalography will show abnormal background patterns in the early preoperative period in infants with congenital heart disease that have preoperative brain injury on magnetic resonance imaging.

METHODS

Twenty-four newborns with congenital heart disease requiring surgery at younger than 30 days of age were prospectively enrolled within the first 3 days of age at a tertiary care pediatric hospital. Infants had amplitude-integrated electroencephalography for 24 hours beginning close to birth and preoperative brain magnetic resonance imaging. The amplitude-integrated electroencephalographies were read to determine if the background pattern was normal, mildly abnormal, or severely abnormal. The presence of seizures and sleep-wake cycling were noted. The preoperative brain magnetic resonance imaging scans were used for brain injury and brain atrophy assessment.

RESULTS

Fifteen of 24 infants had abnormal amplitude-integrated electroencephalography at 0.71 (0-2) (mean [range]) days of age. In five infants, the background pattern was severely abnormal. (burst suppression and/or continuous low voltage). Of the 15 infants with abnormal amplitude-integrated electroencephalography, 9 (60%) had brain injury. One infant with brain injury had a seizure on amplitude-integrated electroencephalography. A severely abnormal background pattern on amplitude-integrated electroencephalography was associated with brain atrophy (P = 0.03) and absent sleep-wake cycling (P = 0.022).

CONCLUSION

Background cerebral activity is abnormal on amplitude-integrated electroencephalography following birth in newborns with congenital heart disease who have findings of brain injury and/or brain atrophy on preoperative brain magnetic resonance imaging.

Subclinical seizures identified by postoperative electroencephalographic monitoring are common after neonatal cardiac surgery

OBJECTIVES

The American Clinical Neurophysiology Society recommends continuous electroencephalographic monitoring after neonatal cardiac surgery because seizures are common, often subclinical, and associated with worse neurocognitive outcomes. We performed a quality improvement project to monitor for postoperative seizures in neonates with congenital heart disease after surgery with cardiopulmonary bypass.

METHODS

We implemented routine continuous electroencephalographic monitoring and reviewed the results for an 18-month period. Clinical data were collected by chart review, and continuous electroencephalographic tracings were interpreted using standardized American Clinical Neurophysiology Society terminology. Electrographic seizures were classified as electroencephalogram-only or electroclinical seizures. Multiple logistic regression was used to assess associations between seizures and potential clinical and electroencephalogram predictors.

RESULTS

A total of 161 of 172 eligible neonates (94%) underwent continuous electroencephalographic monitoring. Electrographic seizures occurred in 13 neonates (8%) beginning at a median of 20 hours after return to the intensive care unit after surgery. Neonates with all types of congenital heart disease had seizures. Seizures were electroencephalogram only in 11 neonates (85%). Status epilepticus occurred in 8 neonates (62%). In separate multivariate models, delayed sternal closure or longer deep hypothermic circulatory arrest duration was associated with an increased risk for seizures. Mortality was higher among neonates with than without seizures (38% vs 3%, P < .001).

CONCLUSIONS

Continuous electroencephalographic monitoring identified seizures in 8% of neonates after cardiac surgery with cardiopulmonary bypass. The majority of seizures had no clinical correlate and would not have been otherwise identified. Seizure occurrence is a marker of greater illness severity and increased mortality. Further study is needed to determine whether seizure identification and management lead to improved outcomes.

Neurodevelopmental outcomes after infant cardiac surgery with circulatory arrest and intermittent perfusion

BACKGROUND

Optimal perfusion strategies for neuroprotection during infant cardiac surgery remain undefined. Despite encouraging experimental data, neurodevelopmental (ND) outcomes after cardiac surgery in neonates and infants using deep hypothermic circulatory arrest (DHCA) with a period of intermittent perfusion have not been reported, and it is not known whether DHCA can be extended while preserving ND outcomes.

METHODS

Cross-sectional ND evaluation with the Bayley Scales of Infant and Toddler Development, Third Edition was conducted at 24 months of age. Retrospective clinical data were extracted from the electronic medical record.

RESULTS

Forty patients underwent cardiac surgery during the first year of life using a period of uninterrupted DHCA (24 patients) or DHCA interrupted by a period of intermittent perfusion (16 patients). Total duration of DHCA ranged from 5 to 74 minutes and did not predict ND scores. Despite a longer exposure to DHCA in the intermittent perfusion group (55 minutes [1,3 interquartile [IQ] 45.3 to 65.5] versus 38 minutes [1,3 IQ 32 to 40.8]), no differences in ND scores were detected. Significant comorbidities, duration of intensive care unit and hospital stay, as well as multiple procedures with DHCA were independent predictors of ND outcomes at 24 months of age.

CONCLUSIONS

Despite extended duration of total DHCA, the use of a period of intermittent perfusion to limit uninterrupted DHCA periods to less than 45 minutes could lead to ND outcomes similar to those of patients exposed to brief periods of DHCA. Deep hypothermic circulatory arrest with intermittent perfusion may facilitate implementation of prospective studies to identify the optimal cerebral perfusion strategy.

Electrographic seizures and status epilepticus in critically ill children and neonates with encephalopathy

Electrographic seizures are seizures that are evident on EEG monitoring. They are common in critically ill children and neonates with acute encephalopathy. Most electrographic seizures have no associated clinical changes, and continuous EEG monitoring is necessary for identification. The effect of electrographic seizures on outcome is the focus of active investigation. Studies have shown that a high burden of electrographic seizures is associated with worsened clinical outcome after adjustment for cause and severity of brain injury, suggesting that a high burden of such seizures might independently contribute to secondary brain injury. Further research is needed to determine whether identification and management of electrographic seizures reduces secondary brain injury and improves outcome in critically ill children and neonates.

Neurodevelopmental outcome in children with congenital heart disease

Children with congenital heart disease (CHD) have multiple factors contributing toward their risk of later neurodevelopmental difficulties. With earlier diagnosis and improved survival rates, the management of CHD now includes the recognition of neurodevelopmental risks and optimisation of neurodevelopmental outcomes is emphasised. Neuroimaging studies have shown early differences in brain development for children with CHD, who then are vulnerable to additional brain injury in the perinatal period. For some children, complications and co-morbidities may further increase the risk of brain injury. Synthesis of multiple factors is necessary to estimate neurodevelopmental prognosis for an individual child. Long-term neurodevelopmental follow-up of children with CHD is warranted for early identification of and intervention for difficulties.

A review of long-term EEG monitoring in critically ill children with hypoxic-ischemic encephalopathy, congenital heart disease, ECMO, and stroke

Continuous EEG monitoring is being used with increasing frequency in critically ill children with hypoxic ischemic encephalopathy, congenital heart disease, stroke, and extracorporeal membrane oxygenation (ECMO). The primary indication for EEG monitoring is to identify electrographic seizures and electrographic status epilepticus, which have been associated with worse outcome in some populations. A secondary indication is to provide prognostic information. This review summarizes the available data regarding continuous EEG monitoring in critically ill children with special attention to hypoxic ischemic encephalopathy, congenital heart disease, stroke, and children undergoing ECMO.

Postoperative electroencephalographic seizures are associated with deficits in executive function and social behaviors at 4 years of age following cardiac surgery in infancy

OBJECTIVE

The occurrence of an electroencephalographic (EEG) seizure after surgery for complex congenital heart defects has been associated with worse neurodevelopmental (ND) outcomes. We previously identified postoperative seizures documented by 48-hour EEG monitoring in 11% of 178 neonates and infants. Evaluation at 1 year of age did not identify an adverse effect of an EEG seizure on ND outcomes. The current study was undertaken to determine if testing in the preschool period would identify deficits that become apparent as children develop.

METHODS

The ND outcomes assessed at 4 years of age included cognition, language, attention, impulsivity, executive function, behavior problems, academic achievement, and visual and fine motor skills.

RESULTS

Developmental evaluations were performed in 132 (87%) of 151 survivors. For the entire cohort, the Full-Scale IQ was 95.0 ± 18.5. IQ was 95.1 ± 18.7 for patients without a history of seizure and 93.6 ± 16.7 for those with a history of seizure. After covariate adjustment, occurrence of an EEG seizure was associated with worse executive function (P = .037) and impaired social interactions/restricted behavior (P = .05). Seizures were not significantly associated with worse performance for cognition, language, attention, impulsivity, academic achievement, or motor skills (all P > .1).

CONCLUSIONS

The occurrence of a postoperative seizure is a biomarker of brain injury. This study confirms that postoperative EEG seizures are associated with worse ND outcomes, characterized by impairments of executive function and a higher prevalence of deficits in social interactions and repetitive/restricted behaviors in preschool survivors of cardiac surgery in infancy. However, EEG seizures were not associated with worse cognitive, language, or motor skills.

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.

Continuous electroencephalography monitoring in neonates

As more critically ill term and premature neonates are surviving their acute illness, their long-term neurodevelopmental morbidity is being recognized. Continuous monitoring of cerebral function, with electroencephalography or derived digital trends, can provide key information regarding seizures and background patterns, with direct treatment and prognostic implications. Conventional video-electroencephalography remains the gold standard for neonatal seizure diagnosis and quantification, but can be supplemented by digital trending modalities. Both conventional and amplitude-integrated electroencephalography can provide valuable data regarding the background trends. This review describes indications and methods for continuous electroencephalography monitoring in high-risk neonates.

Which high-risk infants should we follow-up and how should we do it?

Early detection of neurodevelopmental delay and appropriate intervention has been associated with improved academic and social outcomes. Identifying those who are at high risk and might benefit is not straightforward. Approximately 2% of infants are admitted to a neonatal intensive care unit after birth and these babies are known to be at high risk of developmental impairment. While it is well recognised that the extreme preterm infant is at high risk of developmental impairment, there is increasing evidence of a risk in late preterm infants as well as those undergoing major cardiac and non-cardiac surgery. Not all infants are enrolled in multidisciplinary follow-up clinics with easy access to early intervention. These clinics are expensive to run with both limited and conflicting data on their long-term value. This review will concentrate on identifying which infants are at risk, reviewing the aetiology of the risk factors and the efficacy of follow-up clinics.