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

Electrographic monitoring for seizure detection in the neonatal unit: current status and future direction

Neonatal neurocritical intensive care is dedicated to safeguarding the newborn brain by prioritising clinical practices that promote early identification, diagnosis and treatment of brain injuries. The most common newborn neurological emergency is neonatal seizures, which may also be the initial clinical indication of neurological disease. A high seizure burden in the newborn period independently contributes to increased mortality and morbidity. The majority of seizures in newborns are subclinical (without clinical presentation), and hence identification may be difficult. Neuromonitoring techniques most frequently used to monitor brain wave activity include conventional electroencephalography (cEEG) or amplitude-integrated EEG (aEEG). cEEG with video is the gold standard for diagnosing and treating seizures. Many neonatal units do not have access to cEEG, and frequently those that do, have little access to real-time interpretation of monitoring. IMPACT: EEG monitoring is of no benefit to an infant without expert interpretation. Whilst EEG is a reliable cot-side tool and of diagnostic and prognostic use, both conventional EEG and amplitude-integrated EEG have strengths and limitations, including sensitivity to seizure activity and ease of interpretation. Automated seizure detection requires a sensitive and specific algorithm that can interpret EEG in real-time and identify seizures, including their intensity and duration.

The clinical value of amplitude-integrated electroencephalography in a historical cohort with neonatal encephalopathy: A comparison of short-term versus prolonged-period monitoring

BACKGROUND

To compare the amplitude-integrated electroencephalography (aEEG) monitoring (short-term versus prolonged-period) for neonatal seizure detection and outcome.

METHODS

The aEEG monitoring in a historical cohort (n = 88, preterm:42, and term:46) with neonatal encephalopathy between 2010-2022 was re-evaluated for neonatal seizures (electrographic, electro-clinical, and clinical seizures) and EEG background scoring. The cohort was dichotomized: group I (short-period with 6-12 h, n = 36) and group II (prolonged-period with 24-48 h, n = 52). Both monitoring types were evaluated for the diagnostic accuracy of the "patients with seizures" and for outcome characteristics (early death as well as adverse outcomes at 12 months of age).

RESULTS

A total of 67 (76 %) neonates of the cohort were diagnosed as "patients with seizures": electrographic-only seizures in 10 (15 %), electro-clinical seizures in 22 (33 %), and clinical-only seizures in 35 (52 %). The aEEG provides the "patients with seizures" in neonates with a 36.5 % rate with both types of monitoring: 17/36 (47.2 %) with short-term and 15/52 (28.8 %) with prolonged-period monitoring. The prolonged period aEEG had higher diagnostic values for seizure detection (sensitivity = 0.73 and negative predictivity value = 0.81). However, the aEEG background scores were similar for both types of aEEG monitoring, respectively (the mean ± SD: 4.73 ± 2.9 versus 4.4 ± 4. p = 0.837). The aEEG scoring was correlated with the magnitude of brain injury documented with MRI, the early death, and the adverse outcome at 12 months of age.

CONCLUSIONS

Both aEEG types are valuable for monitoring the "patients with seizures" and outcome characteristics.

The effect of acute respiratory events and respiratory stimulants on EEG-recorded brain activity in neonates: A systematic review

Objective

We conducted a systematic review to investigate electroencephalography (EEG) changes during periods of acute respiratory events such as apnoea and the effect of respiratory stimulants on EEG features in infants.

Methods

Studies examining respiration and EEG-recorded brain activity in human neonates between 28 and 42 weeks postmenstrual age were included. Two reviewers independently screened all records and included studies were assessed using the Joanna Briggs Institute Critical Appraisal Tool. The protocol was registered in PROSPERO (CRD42022339873).

Results

We identified 14 studies with a total of 534 infants. Nine articles assessed EEG changes in relation to apnoea, one assessed hiccups, and four investigated the effect of respiratory stimulants. The relationship between neonatal apnoea and EEG changes was inconsistent; EEG suppression and decreased amplitude and frequency were observed during some, but not all, apnoeas. Respiratory stimulants increased EEG continuity compared with before use.

Conclusions

Current studies in this area are constrained by small sample sizes. Diverse exposure definitions and outcome measures impact inference.

Significance

This review highlights the need for further work; understanding the relationship between respiration and the developing brain is key to mitigating the long-term effects of apnoea.

Neonatal Seizures-Perspective in Low-and Middle-Income Countries

Neonatal seizures are the commonest neurological emergency and are associated with poor neurodevelopmental outcome. While they are generally difficult to diagnose and treat, they pose a significant clinical challenge for physicians in low- and middle-income countries (LMIC). They are mostly provoked seizures caused by an acute brain insult such as hypoxic-ischemic encephalopathy (HIE), ischemic stroke, intracranial hemorrhage, infections of the central nervous system, or acute metabolic disturbances. Early onset epilepsy syndromes are less common. Clinical diagnosis of seizures in the neonatal period are frequently inaccurate, as clinical manifestations are difficult to distinguish from nonseizure behavior. Additionally, a high proportion of seizures are electrographic-only without any clinical manifestations, making diagnosis with EEG or aEEG a necessity. Only focal clonic and focal tonic seizures can be diagnosed clinically with adequate diagnostic certainty. Prompt diagnosis and timely treatment are important, with evidence suggesting that early treatment improves the response to antiseizure medication. The vast majority of published studies are from high-income countries, making extrapolation to LMIC impossible, thus highlighting the urgent need for a better understanding of the etiologies, comorbidities, and drug trials evaluating safety and efficacy in LMIC. In this review paper, the authors present the latest data on etiology, diagnosis, classification, and guidelines for the management of neonates with the emphasis on low-resource settings.

Role of Optical Neuromonitoring in Neonatal Encephalopathy-Current State and Recent Advances

Neonatal encephalopathy (NE) in term and near-term infants is a significant global health problem; the worldwide burden of disease remains high despite the introduction of therapeutic hypothermia. Assessment of injury severity and effective management in the neonatal intensive care unit (NICU) relies on multiple monitoring modalities from systemic to brain-specific. Current neuromonitoring tools provide information utilized for seizure management, injury stratification, and prognostication, whilst systemic monitoring ensures multi-organ dysfunction is recognized early and supported wherever needed. The neuromonitoring technologies currently used in NE however, have limitations in either their availability during the active treatment window or their reliability to prognosticate and stratify injury confidently in the early period following insult. There is therefore a real need for a neuromonitoring tool that provides cot side, early and continuous monitoring of brain health which can reliably stratify injury severity, monitor response to current and emerging treatments, and prognosticate outcome. The clinical use of near-infrared spectroscopy (NIRS) technology has increased in recent years. Research studies within this population have also increased, alongside the development of both instrumentation and signal processing techniques. Increasing use of commercially available cerebral oximeters in the NICU, and the introduction of advanced optical measurements using broadband NIRS (BNIRS), frequency domain NIRS (FDNIRS), and diffuse correlation spectroscopy (DCS) have widened the scope by allowing the direct monitoring of oxygen metabolism and cerebral blood flow, both key to understanding pathophysiological changes and predicting outcome in NE. This review discusses the role of optical neuromonitoring in NE and why this modality may provide the next significant piece of the puzzle toward understanding the real time state of the injured newborn brain.