Multi-channel amplitude-integrated EEG characteristics in preterm infants with a normal neurodevelopment at two years of corrected age

The effects of betamethasone on the amplitude integrated EEG of infants born at 34- or 35-weeks gestation

OBJECTIVE

Assess if maternal betamethasone administration at 34-35 weeks accelerated neonatal amplitude integrated EEG (aEEG) maturation.

STUDY DESIGN

Nested, observational cohort in 7 centers participating in the Antenatal Late Preterm Steroid randomized trial. Up to 2 aEEGs were obtained in neonates born from 340-356 weeks gestation before 72 h (aEEG 1) and at 5-7 days (aEEG 2) if hospitalized. Personnel and aEEG central readers were masked to the intervention. The primary outcome was maturation reflected by cycle frequency; secondary outcomes were border voltage, span, and discontinuity.

RESULTS

58 neonates were enrolled (betamethasone, 28, placebo, 30). On aEEG 1, cycle frequency did not differ, but betamethasone exposed infants had a greater lower border voltage and a broader span. On aEEG 2, both groups displayed increases in lower border voltage.

CONCLUSIONS

Betamethasone associated changes in lower border voltage support accelerated electrical activity. Further investigation is needed to understand the broader span.

Attention Measurement of an Autism Spectrum Disorder User Using EEG Signals: A Case Study

Autism Spectrum Disorder (ASD) is a neurodevelopmental life condition characterized by problems with social interaction, low verbal and non-verbal communication skills, and repetitive and restricted behavior. People with ASD usually have variable attention levels because they have hypersensitivity and large amounts of environmental information are a problem for them. Attention is a process that occurs at the cognitive level and allows us to orient ourselves towards relevant stimuli, ignoring those that are not, and act accordingly. This paper presents a methodology based on electroencephalographic (EEG) signals for attention measurement in a 13-year-old boy diagnosed with ASD. The EEG signals are acquired with an Epoc+ Brain–Computer Interface (BCI) via the Emotiv Pro platform while developing several learning activities and using Matlab 2019a for signal processing. For this article, we propose to use electrodes F3, F4, P7, and P8. Then, we calculate the band power spectrum density to detect the Theta Relative Power (TRP), Alpha Relative Power (ARP), Beta Relative Power (BRP), Theta–Beta Ratio (TBR), Theta–Alpha Ratio (TAR), and Theta/(Alpha+Beta), which are features related to attention detection and neurofeedback. We train and evaluate several machine learning (ML) models with these features. In this study, the multi-layer perceptron neural network model (MLP-NN) has the best performance, with an AUC of 0.9299, Cohen’s Kappa coefficient of 0.8597, Matthews correlation coefficient of 0.8602, and Hamming loss of 0.0701. These findings make it possible to develop better learning scenarios according to the person’s needs with ASD. Moreover, it makes it possible to obtain quantifiable information on their progress to reinforce the perception of the teacher or therapist.

Early preterm infants with abnormal psychomotor neurodevelopmental outcome at age two show alterations in amplitude-integrated electroencephalography signals

INTRODUCTION

Recent studies showed that neurodevelopment in preterm infants can be predicted by using amplitude-integrated electroencephalography (aEEG)-derived parameters. In our previous study we demonstrated that aEEG could be useful in predicting neurodevelopmental outcome in very preterm infants at the corrected age of 2 years.

AIM

The aim of this study was to further evaluate aEEG for predicting neurodevelopmental outcome at the at the corrected age of 2 years in preterm infants.

METHODS

Between July 2010 and June 2016 440 very preterm infants were eligible for the study at Innsbruck Medical University Hospital. The aEEG was evaluated for the Burdjalov score in 306 preterm infants (mean gestational age 29.5 weeks; range: 24.1-31.9 weeks). At the corrected age of 2 years outcome was assessed by the Bayley Scales of Infant and Toddler Development.

RESULTS

The cohort was divided into three subgroups: 248 infants with normal outcome, 40 infants with delayed outcome and 18 infants with abnormal outcome. Burdjalov scores were lower in infants with delayed outcome than in infants with normal outcome and even lower in infants with abnormal outcome. Post-hoc analysis showed significant differences between normal and delayed psychomotor outcome at 18-24 h (5 (3;6) versus 3 (3;5), p = .024), 30-36 h (6 (4;8) versus 4 (4;6), p = .033), 42-48 h (7 (5;8.5) versus 4 (4;7), p = .003), 54-60 h (7 (6;9) versus 5 (4;7), p = .003), 66-72 h (8 (6;9) versus 6.5 (4.25;7.75), p = .027) and week one (8 (7;10) versus 6.5 (5;8), p = .021). Additionally, when comparing normal to abnormal outcome, a significant difference was found at week four (12 (9;12) versus 8 (7;10), p = .024). The Burdjalov score was only predictive for a delayed psychomotor outcome, presenting the highest area under the curve (0.690) at week two of life.

CONCLUSION

We observed differences in aEEG signals and neurodevelopmental outcome at the corrected age of 2 years, especially for psychomotor outcome. The predictive value of the Burdjalov score regarding neurodevelopmental outcome at the corrected age of 2 years in preterm infants was low.

Amplitude-integrated electroencephalography shows alterations in children born preterm displaying poor literacy precursor skills

AIM

To assess whether amplitude-integrated electroencephalography (aEEG) alterations in the newborn period are associated with poor precursor skills of literacy at five years of age in children born preterm.

METHODS

Between October 2007 and September 2011 248 preterm infants were eligible for the study at Innsbruck Medical University Hospital. aEEG was analysed for dominating background activity, calculation of the percentage of continuous activity, the Burdjalov scoring system, the minimum, mean and maximum amplitude. At the age of five years, we evaluated preterm born children by the Bielefelder screening (BISC) to assess for early diagnosis of reading problems and weak spelling and classified them as normal performers (n = 64) or poor performers (n = 20). Completion of testing was not possible for one infant.

RESULTS

The minimum amplitude was significantly lower in the poor BISC performance group as compared to the normal BISC performance group at postnatal week two. The percentage of continuous background activity was significantly higher in infants with normal BISC performance than in infants with poor BISC performance at postnatal week three.

CONCLUSION

Children with poor developed precursor skills of literacy showed alterations in aEEG signals. The aEEG could be useful in further diagnosing preterm infants at risk for developmental complications.

Amplitude-Integrated EEG and Brain Sparing in Preterm Small-for-Gestational-Age Infants

PURPOSE

Preterm small-for-gestational-age (SGA) infants are at risk for a high mortality rate and impaired cognitive development. Only a few studies have focused on amplitude-integrated EEG (aEEG) in preterm SGA infants. They have been shown to have a slower rate of brain maturation, but these findings have not consistently been related to neurodevelopmental outcomes. The aim of our study was to evaluate early aEEG monitoring in SGA compared with adequate-for-gestational-age preterms.

METHODS

This prospective cohort study enrolled infants with very low birth weight who were admitted to the neonatal intensive care unit at Hospital Puerta del Mar, Cádiz, Spain, from June 2009 to September 2012. This study was a subanalysis of SGA from the global cohort previously described by our group. Adverse outcome included severe intraventricular hemorrhage and/or death. Cerebral function was monitored using aEEG recordings during the first 72 hours of life.

RESULTS

Preterm SGA infants (18 SGA in the global cohort of 92 patients) had lower 1- and 5-minute Apgar scores, higher score for neonatal acute physiology perinatal extension II scores, and higher proportion of adverse outcomes. When comparing preterm adequate-for-gestational-age infants with SGA infants with good prognosis, those with SGA had more mature and continuous aEEG patterns. Low margin amplitude depression was not as severe in these patients, and a higher proportion of these patients developed sleep-wake cycles.

CONCLUSIONS

The results of our study suggest that SGA infants with a good prognosis have a more mature aEEG pattern than preterm adequate-for-gestational-age patients with the same outcome. These findings support the brain sparing theory in SGA infants.

Multipotent adult progenitor cells for hypoxic-ischemic injury in the preterm brain

Background

Preterm infants are at risk for hypoxic-ischemic encephalopathy. No therapy exists to treat this brain injury and subsequent long-term sequelae. We have previously shown in a well-established pre-clinical model of global hypoxia-ischemia (HI) that mesenchymal stem cells are a promising candidate for the treatment of hypoxic-ischemic brain injury. In the current study, we investigated the neuroprotective capacity of multipotent adult progenitor cells (MAPC^®), which are adherent bone marrow-derived cells of an earlier developmental stage than mesenchymal stem cells and exhibiting more potent anti-inflammatory and regenerative properties.

Methods

Instrumented preterm sheep fetuses were subjected to global hypoxia-ischemia by 25 min of umbilical cord occlusion at a gestational age of 106 (term ~147) days. During a 7-day reperfusion period, vital parameters (e.g., blood pressure and heart rate; baroreceptor reflex) and (amplitude-integrated) electroencephalogram were recorded. At the end of the experiment, the preterm brain was studied by histology.

Results

Systemic administration of MAPC therapy reduced the number and duration of seizures and prevented decrease in baroreflex sensitivity after global HI. In addition, MAPC cells prevented HI-induced microglial proliferation in the preterm brain. These anti-inflammatory effects were associated with MAPC-induced prevention of hypomyelination after global HI. Besides attenuation of the cerebral inflammatory response, our findings showed that MAPC cells modulated the peripheral splenic inflammatory response, which has been implicated in the etiology of hypoxic-ischemic injury in the preterm brain.

Conclusions

In a pre-clinical animal model MAPC cell therapy improved the functional and structural outcome of the preterm brain after global HI. Future studies should establish the mechanism and long-term therapeutic effects of neuroprotection established by MAPC cells in the developing preterm brain exposed to HI. Our study may form the basis for future clinical trials, which will evaluate whether MAPC therapy is capable of reducing neurological sequelae in preterm infants with hypoxic-ischemic encephalopathy.

Serial aEEG recordings in a cohort of extremely preterm infants: feasibility and safety

OBJECTIVE

Amplitude-integrated electroencephalography (aEEG) monitoring is increasing in the neonatal population, but the safety and feasibility of performing aEEG in extremely preterm infants have not been systematically evaluated.

STUDY DESIGN

Inborn infants 23(0/7) to 28(6/7) weeks gestation or birth weight 401 to 1000 g were eligible. Serial, 6-h aEEG recordings were obtained from first week of life until 36 weeks postmenstrual age. Adverse events were documented, and surveys evaluated the impact of the aEEGs on routine care. Success of performing aEEGs according to protocol and aEEG quality were assessed.

RESULT

A total of 102 infants were enrolled, with 755 recordings performed. 83% of recordings were performed according to schedule, and 96% were without adverse event. Bedside nurses reported no interference with routine care for 89% of recordings. 92% of recordings had acceptable signal quality.

CONCLUSION

Serial aEEG monitoring is safe in preterm infants, with few adverse events and general acceptance by nursing staff.

Propofol administration to the maternal-fetal unit improved fetal EEG and influenced cerebral apoptotic pathway in preterm lambs suffering from severe asphyxia

BACKGROUND

Term and near-term infants are at high risk of developing brain injury and life-long disability if they have suffered from severe perinatal asphyxia. We hypothesized that propofol administration to the maternal-fetal unit can diminish cerebral injury in term and near-term infant fetuses in states of progressive severe asphyxia.

METHODS

Forty-four late preterm lambs underwent total umbilical cord occlusion (UCO) or sham treatment in utero. UCO resulted in global asphyxia and cardiac arrest. After emergency cesarean section under either maternal propofol or isoflurane anesthesia, the fetuses were resuscitated and subsequently anesthetized the same way as their mothers.

RESULTS

Asphyctic lambs receiving isoflurane showed a significant increase of total and low-frequency spectral power in bursts indicating seizure activity and more burst-suppression with a marked increase of interburst interval length during UCO. Asphyctic lambs receiving propofol showed less EEG changes. Propofol increased levels of anti-apoptotic B-cell lymphoma-extra large (Bcl-xL) and phosphorylated STAT-3 and reduced the release of cytochrome c from the mitochondria and the protein levels of activated cysteinyl aspartate-specific protease (caspase)-3, -9, and N-methyl-d-aspartate (NMDA) receptor.

CONCLUSIONS

Improvement of fetal EEG during and after severe asphyxia could be achieved by propofol treatment of the ovine maternal-fetal unit. The underlying mechanism is probably the reduction of glutamate-induced cytotoxicity by down-regulation of NMDA receptors and an inhibition of the mitochondrial apoptotic pathway.

Low-voltage pattern and absence of sleep-wake cycles are associated with severe hemorrhage and death in very preterm infants

Amplitude integrated electroencephalogaphy (aEEG) is becoming an important tool for the assessment of cerebral activity in preterm newborns. Describing the relationship between early aEEG patterns and intraventricular hemorrhage (IVH) can improve our knowledge of neurological injury in the preterm newborn. The aim of this prospective study was to identify early changes in the aEEG in premature newborns that could be associated to severe neurological lesion/death. Preterm newborns with a birth weight ≤1,500 g and/or 32 weeks of gestation were included. aEEG monitoring was performed during the first 72 h of life. A qualitative analysis of the aEEG recordings was performed, based on continuity, sleep-wake cycles (SWCs), inferior lower margin amplitude (LMA), and bandwidth (BW). Key outcomes were severe IVH and/or death. Ninety-two subjects were included (mean gestational age 28 weeks). In 28.6 % of subjects with HIV III/IHP, a low-voltage pattern was observed. A statistically significant relationship was found between low-voltage tracings and death and neurological lesion/death. Absent SWCs during the first 72 h were also related to death.

CONCLUSION

Early aEEG patterns can be predictive of neurological outcome in the preterm newborn. Low-voltage tracing and absence of SWCs are associated with severe neurological lesions/death.

Modulation of EEG spectral edge frequency during patterned pneumatic oral stimulation in preterm infants

BACKGROUND

Stimulation of the nervous system plays a central role in brain development and neurodevelopmental outcomes. Thalamocortical and corticocortical development is diminished in premature infants and correlated to electroencephalography (EEG) progression. The purpose of this study was to determine the effects of orocutaneous stimulation on the modulation of spectral edge frequency fc = 90% (SEF-90), which is derived from EEG recordings in preterm infants.

METHODS

A total of 22 preterm infants were randomized to experimental and control conditions. Pulsed orocutaneous stimulation was presented during gavage feedings begun at ~32 wk postmenstrual age. The SEF-90 was derived from two-channel EEG recordings.

RESULTS

Compared with the control condition, the pulsed orocutaneous stimulation produced a significant reorganization of SEF-90 in the left (P = 0.005) and right (P < 0.0001) hemispheres. Notably, the left and right hemispheres showed a reversal in the polarity of frequency shift, demonstrating hemispheric asymmetry in the frequency domain. Pulsed orocutaneous stimulation also produced a significant pattern of short-term cortical adaptation and a long-term neural adaptation manifested as a 0.5 Hz elevation in SEF-90 after repeated stimulation sessions.

CONCLUSION

This is the first study to demonstrate the modulating effects of a servo-controlled oral somatosensory input on the spectral features of EEG activity in preterm infants.

Systemic G-CSF attenuates cerebral inflammation and hypomyelination but does not reduce seizure burden in preterm sheep exposed to global hypoxia-ischemia

Hypoxic-ischemic encephalopathy (HIE) is common in preterm infants, but currently no curative therapy is available. Cell-based therapy has a great potential in the treatment of hypoxic-ischemic preterm brain injury. Granulocyte-colony stimulating factor (G-CSF) is known to mobilize endogenous hematopoietic stem cells (HSC) and promotes proliferation of endogenous neural stem cells. On these grounds, we hypothesized that systemic G-CSF would be neuroprotective in a large translational animal model of hypoxic-ischemic injury in the preterm brain. Global hypoxia-ischemia (HI) was induced by transient umbilical cord occlusion in instrumented preterm sheep. G-CSF treatment (100μg/kg intravenously, during five consecutive days) was started one day before the global HI insult to ascertain mobilization of endogenous stem cells within the acute phase after global HI. Mobilization of HSC and neutrophils was studied by flow cytometry. Brain sections were stained for microglia (IBA-1), myelin basic protein (MBP) and myeloperoxidase (MPO) to study microglial proliferation, white matter injury and neutrophil invasion respectively. Electrographic seizure activity was analyzed using amplitude-integrated electroencephalogram (aEEG). G-CSF effectively mobilized CD34-positive HSC in the preterm sheep. In addition, G-CSF caused marked mobilization of neutrophils, but did not influence enhanced invasion of neutrophils into the preterm brain after global HI. Microglial proliferation and hypomyelination following global HI were reduced as a result of G-CSF treatment. G-CSF did not cause a reduction of the electrographic seizure activity after global HI. In conclusion, G-CSF induced mobilization of endogenous stem cells which was associated with modulation of the cerebral inflammatory response and reduced white matter injury in an ovine model of preterm brain injury after global HI. G-CSF treatment did not improve neuronal function as shown by seizure analysis. Our study shows that G-CSF treatment has neuroprotective potential following hypoxic-ischemic injury in the preterm brain.

Mesenchymal stem cells induce T-cell tolerance and protect the preterm brain after global hypoxia-ischemia

Hypoxic-ischemic encephalopathy (HIE) in preterm infants is a severe disease for which no curative treatment is available. Cerebral inflammation and invasion of activated peripheral immune cells have been shown to play a pivotal role in the etiology of white matter injury, which is the clinical hallmark of HIE in preterm infants. The objective of this study was to assess the neuroprotective and anti-inflammatory effects of intravenously delivered mesenchymal stem cells (MSC) in an ovine model of HIE. In this translational animal model, global hypoxia-ischemia (HI) was induced in instrumented preterm sheep by transient umbilical cord occlusion, which closely mimics the clinical insult. Intravenous administration of 2 x 10(6) MSC/kg reduced microglial proliferation, diminished loss of oligodendrocytes and reduced demyelination, as determined by histology and Diffusion Tensor Imaging (DTI), in the preterm brain after global HI. These anti-inflammatory and neuroprotective effects of MSC were paralleled by reduced electrographic seizure activity in the ischemic preterm brain. Furthermore, we showed that MSC induced persistent peripheral T-cell tolerance in vivo and reduced invasion of T-cells into the preterm brain following global HI. These findings show in a preclinical animal model that intravenously administered MSC reduced cerebral inflammation, protected against white matter injury and established functional improvement in the preterm brain following global HI. Moreover, we provide evidence that induction of T-cell tolerance by MSC might play an important role in the neuroprotective effects of MSC in HIE. This is the first study to describe a marked neuroprotective effect of MSC in a translational animal model of HIE.

Changes of amplitude integration electroencephalogram (aEEG) in different maturity preterm infant

BACKGROUND

With the improvement of perinatal care and neonatal intensive care technology in recent years, a preterm infant, especially with small gestational age and very low birth weight, survives more and more. At the same time, adverse neurodevelopmental prognosis caused by brain damage in preterm infant also increased significantly. Preterm infant brain injury has become the most important factor for early death and neurodevelopment of preterm infant.

METHODS

Amplitude integration electroencephalogram (aEEG) has an important clinical value in the assessment of brain development in the maturity of preterm infant. With the application of a neonatal brain function monitor, we value the aEEG graphic continuity, periodicity, narrowband lower margin amplitude, and bandwidth score and analyze wide- and narrowband on the lower bounds of voltage and bandwidth.

RESULTS

The graphics of preterm infant aEEG become mature with the growth of the gestational age (1). With the growth of corrected gestational age, the aEEG graphics of preterm infant has the following feature: lower bound voltage of narrowband rising and width narrowing of narrowband (2). Extrauterine life can speed up the maturation of aEEG graphics (3).

CONCLUSIONS

The aEEG technology is a noninvasive, operable, and simple analysis and suitable for application in the newborn intensive care unit.