Neuromonitoring in neonatal critical care part I: neonatal encephalopathy and neonates with possible seizures

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.

Retrospective study on neonatal seizures in a tertiary center of northern Italy after ILAE classification: Incidence, seizure type, EEG and etiology

OBJECTIVE

We aimed to evaluate epidemiology, seizure type, EEG, and etiology of neonatal seizures (NS) in a tertiary neonatal intensive care unit.

METHODS

Data on infants with a neurophysiological confirmation of NS were collected between 2009 and 2022. Seizure types and epileptic syndromes were classified by the ILAE classification and EEG by the Italian Neonatal Seizure Collaborative Network (INNESCO) score.

RESULTS

Out of 91,253 neonates, 145 presented with NS; 69.7 % were born at term and 30.3 % were preterm infants. The incidence of NS in neonates born at our center was 1.2 per 1,000 live newborns (96/80697 neonates) while in the entire neonatal population admitted to our center it was 1.6 per 1,000 live births, increasing with lower preterm age. Compared to previous studies, we found a lower proportion of hypoxic-ischemic encephalopathy (HIE) (23.4 %) and a higher rate of genetic contribution (26.2 %). The infection rate was higher in preterm (31.8 %) than in full term (9.9 %) infants. Electrographic seizures were associated with acute provoked seizures (35.9 %), preterm age (52.3 %), and HIE (52.9 %). Vascular etiology was associated with focal clonic seizures (56.8 %). Non-structural neonatal genetic epilepsy was associated with sequential seizures (68.2 %), particularly KCNQ2 and SCN2A epilepsy. Background EEG was abnormal in all HIE, infections (85.7 %) and metabolic NS (83.3 %). In genetic epilepsy, background EEG depended on the epileptic syndrome: normal in 80 % of self-limited neonatal epilepsy and abnormal in 77.8 % of developmental and epileptic encephalopathy. Electroclinical seizures were associated with focal onset, while electrographic seizures correlated with a multifocal onset.

CONCLUSIONS

A low incidence of HIE and a high incidence of genetic etiology were observed in our cohort of NS. Seizure type and EEG features are fundamental to address etiology.

Relationship between EEG spectral power and dysglycemia with neurodevelopmental outcomes after neonatal encephalopathy

OBJECTIVE

We investigated how electroencephalography (EEG) quantitative measures and dysglycemia relate to neurodevelopmental outcomes following neonatal encephalopathy (NE).

METHODS

This retrospective study included 90 neonates with encephalopathy who received therapeutic hypothermia. EEG absolute spectral power was calculated during post-rewarming and 2-month follow-up. Measures of dysglycemia (hypoglycemia, hyperglycemia, and glycemic lability) and glucose variability were computed for the first 48 h of life. We evaluated the ability of EEG and glucose measures to predict neurodevelopmental outcomes at ≥ 18 months, using logistic regressions (with area under the receiver operating characteristic [AUROC] curves).

RESULTS

The post-rewarming global delta power (average all electrodes), hyperglycemia and glycemic lability predicted moderate/severe neurodevelopmental outcome separately (AUROC = 0.8, 95%CI [0.7,0.9], p < .001) and even more so when combined (AUROC = 0.9, 95%CI [0.8,0.9], p < .001). After adjusting for NE severity and magnetic resonance imaging (MRI) brain injury, only global delta power remained significantly associated with moderate/severe neurodevelopmental outcome (odds ratio [OR] = 0.9, 95%CI [0.8,1.0], p = .04), gross motor delay (OR = 0.9, 95%CI [0.8,1.0], p = .04), global developmental delay (OR = 0.9, 95%CI [0.8,1.0], p = .04), and auditory deficits (OR = 0.9, 95%CI [0.8,1.0], p = .03).

CONCLUSIONS

In NE, global delta power post-rewarming was predictive of outcomes at ≥ 18 months.

SIGNIFICANCE

EEG markers post-rewarming can aid prediction of neurodevelopmental outcomes following NE.

Neuromonitoring in neonatal intensive care units-an important need towards individualized neuroprotective care

Neuromonitoring has been widely accepted as an important part in neonatal care. Amplitude-integrated EEG (aEEG) and near-infrared spectroscopy (NIRS) are often mentioned in this context, though being only a part of the fully array of methods and examinations that could be considered neuromonitoring. Within the broad array of medical conditions that could be encountered in a neonatal patient, it is important to be aware of the indications for neuromonitoring and especially which neuromonitoring technique to use best for the individual condition. aEEG is now a widely accepted neuromonitor in neonatology with its value in hypoxic events and seizures only rarely questioned. Other methods like NIRS still have to prove themselves in the future. The SafeBoosC-III trial showed that it still remains difficult for some of these methods to prove their value for the improvement of outcome. Bute future developments such as multimodal neuromonitoring with data integration and artificial intelligence analysis could improve the value of these methods.

Quantitative EEG features during the first day correlate to clinical outcome in perinatal asphyxia

OBJECTIVE

To assess whether computational electroencephalogram (EEG) measures during the first day of life correlate to clinical outcomes in infants with perinatal asphyxia with or without hypoxic-ischemic encephalopathy (HIE).

METHODS

We analyzed four-channel EEG monitoring data from 91 newborn infants after perinatal asphyxia. Altogether 42 automatically computed amplitude- and synchrony-related EEG features were extracted as 2-hourly average at very early (6 h) and early (24 h) postnatal age; they were correlated to the severity of HIE in all infants, and to four clinical outcomes available in a subcohort of 40 newborns: time to full oral feeding (nasogastric tube NGT), neonatal brain MRI, Hammersmith Infant Neurological Examination (HINE) at three months, and Griffiths Scales at two years.

RESULTS

At 6 h, altogether 14 (33%) EEG features correlated significantly to the HIE grade ([r]= 0.39-0.61, p < 0.05), and one feature correlated to NGT ([r]= 0.50). At 24 h, altogether 13 (31%) EEG features correlated significantly to the HIE grade ([r]= 0.39-0.56), six features correlated to NGT ([r]= 0.36-0.49) and HINE ([r]= 0.39-0.61), while no features correlated to MRI or Griffiths Scales.

CONCLUSIONS

Our results show that the automatically computed measures of early cortical activity may provide outcome biomarkers for clinical and research purposes.

IMPACT

The early EEG background and its recovery after perinatal asphyxia reflect initial severity of encephalopathy and its clinical recovery, respectively. Computational EEG features from the early hours of life show robust correlations to HIE grades and to early clinical outcomes. Computational EEG features may have potential to be used as cortical activity biomarkers in early hours after perinatal asphyxia.

Quality improvement and outcomes for neonates with hypoxic-ischemic encephalopathy: obstetrics and neonatal perspectives

Despite significant improvement in perinatal care and research, hypoxic ischemic encephalopathy (HIE) remains a global healthcare challenge. From both published research and reports of QI initiatives, we have identified a number of distinct opportunities that can serve as targets of quality improvement (QI) initiatives focused on reducing HIE. Specifically, (i) implementation of perinatal interventions to anticipate and timely manage high-risk deliveries; (ii) enhancement of team training and communication; (iii) optimization of early HIE diagnosis and management in referring centers and during transport; (iv) standardization of the approach when managing neonates with HIE during therapeutic hypothermia; (v) and establishment of protocols for family integration and follow-up, have been identified as important in successful QI initiatives. We also provide a framework and examples of tools that can be used to support QI work and discuss some of the perceived challenges and future opportunities for QI targeting HIE.

Association of aEEG and brain injury severity on MRI at term-equivalent age in preterm infants

AIM

Measures to detect and monitor brain injury in preterm infants are amplitude-integrated electroencephalography (aEEG) and magnetic resonance imaging (MRI). To investigate the association between aEEG and MRI in a large cohort of preterm infants. Five hundred and twenty-three preterm infants were included in the study.

METHODS

AEEG was interpreted for the total maturation score (TMS) according to Burdjalov. Cerebral MRI was evaluated using a validated scoring system by Kidokoro.

RESULTS

One hundred and forty-six infants (27.9%) showed some form of brain injury, with 111 infants (21.2%) showing mild injury and 35 (6.7%) showing severe injury. TMS were significantly higher in infants without injury compared to severe injury. When comparing infants with isolated intraventricular haemorrhage  to infants without brain injury, TMS were significantly lower.

CONCLUSION

Prediction of adverse outcome is an important aspect of neonatal care. The combination of diagnostic measures evaluating brain injury might enhance our abilities in neonatal care to provide accurate information about later outcome. Early aEEG is predictive for the severity of brain injury detected by MRI at term-equivalent age. Whether aEEG is also predictive for neurodevelopmental outcome needs to be further investigated in relation to the various patterns of preterm brain injury.

Neonatal Hypoxic-Ischemic Encephalopathy and Hypothermia Treatment

Neonatal hypoxic-ischemic encephalopathy (HIE) is an important clinical entity because it is associated with death and long-term disability, including cognitive impairment, cerebral palsy, seizures, and neurosensory deficits. Over the past 40 years, there has been an intensive search to identify therapies to improve the prognosis of neonates with HIE. Hypothermia treatment represents the culmination of laboratory investigations including small and large animal studies, followed by pilot human studies, and, finally, randomized controlled trials to establish efficacy and safety. Clinical trials have demonstrated that hypothermia treatment reduces mortality and improves early childhood outcome among survivors. Hypoxic-ischemic encephalopathy is a multi-system disease process that requires intensive medical support for brain monitoring and monitoring of non-central nervous system organ dysfunction. Treatment must be conducted in a level III or IV neonatal intensive care unit with infrastructure for an integrated approach to care for critically ill neonates. Hypothermia treatment is the first and currently the only therapy to improve outcomes for neonates with HIE and indicates that HIE is modifiable. However, outcomes likely can be improved further. Hypothermia treatment has accelerated investigation of other therapies to combine with hypothermia. It has also stimulated a more intensive approach to brain monitoring, which allows earlier intervention for complications. Finally, HIE and hypothermia treatment negatively influences the psychological state of affected families, and there is growing recognition of the importance of trauma-informed principles to guide medical professionals.

Biomaterials and bioelectronics for self-powered neurostimulation

Self-powered neurostimulation via biomaterials and bioelectronics innovation has emerged as a compelling approach to explore, repair, and modulate neural systems. This review examines the application of self-powered bioelectronics for electrical stimulation of both the central and peripheral nervous systems, as well as isolated neurons. Contemporary research has adeptly harnessed biomechanical and biochemical energy from the human body, through various mechanisms such as triboelectricity, piezoelectricity, magnetoelasticity, and biofuel cells, to power these advanced bioelectronics. Notably, these self-powered bioelectronics hold substantial potential for delivering neural stimulations that are customized for the treatment of neurological diseases, facilitation of neural regeneration, and the development of neuroprosthetics. Looking ahead, we expect that the ongoing advancements in biomaterials and bioelectronics will drive the field of self-powered neurostimulation toward the realization of more advanced, closed-loop therapeutic solutions, paving the way for personalized and adaptable neurostimulators in the coming decades.

Introduction of Amplitude-Integrated Electroencephalography (aEEG) Monitoring in a Level 2 NICU: Improving the Quality of Care for Neurologically At-Risk Newborns

Amplitude-integrated electroencephalography (aEEG) is a bedside tool for continuous monitoring of brain activity with the possibility of real-time interpretation. Amplitude-integrated electroencephalography is routinely used in Canadian tertiary NICUs; however, its use in Level 2 NICUs has been limited. A bedside aEEG program was introduced in a Level 2 NICU in order to help facilitate the timely transfer of neurologically compromised infants and keep mother-infant dyads together where reassurance of appropriate neurological status could be attained. A monitoring guideline and educational program were developed. The introduction of aEEG monitoring enhanced the care provided to neurologically at-risk newborns. This experience can be used as a framework for other Level 2 NICUs who may wish to embark upon a similar initiative.