Altered working memory-related brain responses and white matter microstructure in extremely preterm-born children at school age

Preterm birth poses a risk for neurocognitive and behavioral development. Preterm children, who have not been diagnosed with neurological or cognitive deficits, enter normal schools and are expected to succeed as their term-born peers. Here we tested the hypotheses that despite an uneventful development after preterm birth, these children might exhibit subtle abnormalities in brain function and white-matter microstructure at school-age. We recruited 7.5-year-old children born extremely prematurely (<28 weeks' gestation), and age- and gender-matched term-born controls (≥37 weeks' gestation). We applied fMRI during working-memory (WM) tasks, and investigated white-matter microstructure with diffusion tensor imaging. Compared with controls, preterm-born children performed WM tasks less accurately, had reduced activation in several right prefrontal areas, and weaker deactivation of right temporal lobe areas. The weaker prefrontal activation correlated with poorer WM performance. Preterm-born children had higher fractional anisotropy (FA) and lower diffusivity than controls in several white-matter areas, and in the posterior cerebellum, the higher FA associated with poorer visuospatial test scores. In controls, higher FA and lower diffusivity correlated with faster WM performance. Together these findings demonstrate weaker WM-related brain activations and altered white matter microstructure in children born extremely preterm, who had normal global cognitive ability.

Effect of allopurinol in addition to hypothermia treatment in neonates for hypoxic-ischemic brain injury on neurocognitive outcome (ALBINO): study protocol of a blinded randomized placebo-controlled parallel group multicenter trial for superiority (phase III)

Background

Perinatal asphyxia and resulting hypoxic-ischemic encephalopathy is a major cause of death and long-term disability in term born neonates. Up to 20,000 infants each year are affected by HIE in Europe and even more in regions with lower level of perinatal care. The only established therapy to improve outcome in these infants is therapeutic hypothermia. Allopurinol is a xanthine oxidase inhibitor that reduces the production of oxygen radicals as superoxide, which contributes to secondary energy failure and apoptosis in neurons and glial cells after reperfusion of hypoxic brain tissue and may further improve outcome if administered in addition to therapeutic hypothermia.

Methods

This study on the effects of ALlopurinol in addition to hypothermia treatment for hypoxic-ischemic Brain Injury on Neurocognitive Outcome (ALBINO), is a European double-blinded randomized placebo-controlled parallel group multicenter trial (Phase III) to evaluate the effect of postnatal allopurinol administered in addition to standard of care (including therapeutic hypothermia if indicated) on the incidence of death and severe neurodevelopmental impairment at 24 months of age in newborns with perinatal hypoxic-ischemic insult and signs of potentially evolving encephalopathy. Allopurinol or placebo will be given in addition to therapeutic hypothermia (where indicated) to infants with a gestational age ≥ 36 weeks and a birth weight ≥ 2500 g, with severe perinatal asphyxia and potentially evolving encephalopathy. The primary endpoint of this study will be death or severe neurodevelopmental impairment versus survival without severe neurodevelopmental impairment at the age of two years. Effects on brain injury by magnetic resonance imaging and cerebral ultrasound, electric brain activity, concentrations of peroxidation products and S100B, will also be studied along with effects on heart function and pharmacokinetics of allopurinol after iv-infusion.

Discussion

This trial will provide data to assess the efficacy and safety of early postnatal allopurinol in term infants with evolving hypoxic-ischemic encephalopathy. If proven efficacious and safe, allopurinol could become part of a neuroprotective pharmacological treatment strategy in addition to therapeutic hypothermia in children with perinatal asphyxia.

Trial registration

NCT03162653, www.ClinicalTrials.gov, May 22, 2017.

Bedside neurophysiological tests can identify neonates with stroke leading to cerebral palsy

OBJECTIVE

The unspecific symptoms of neonatal stroke still challenge its bedside diagnosis. We studied the accuracy of routine electroencephalography (EEG) and simultaneously recorded somatosensory evoked potentials (EEG-SEP) for diagnosis and outcome prediction of neonatal stroke.

METHODS

We evaluated EEG and EEG-SEPs from a hospital cohort of 174 near-term neonates with suspected seizures or encephalopathy, 32 of whom were diagnosed with acute ischemic or hemorrhagic stroke in MRI. EEG was scored for background activity and seizures. SEPs were classified as present or absent. Developmental outcome of stroke survivors was evaluated from medical records at 8- to 18-months age.

RESULTS

The combination of continuous EEG and uni- or bilaterally absent SEP (n = 10) was exclusively seen in neonates with a middle cerebral artery (MCA) stroke (specificity 100%). Moreover, 80% of the neonates with this finding developed with cerebral palsy. Bilaterally present SEPs did not exclude stroke, but predicted favorable neuromotor outcome in stroke survivors (positive predictive value 95%).

CONCLUSIONS

Absent SEP combined with continuous EEG background in near-term neonates indicates an MCA stroke and a high risk for cerebral palsy.

SIGNIFICANCE

EEG-SEP offers a bedside method for diagnostic screening and a reliable prediction of neuromotor outcome in neonates suspected of having a stroke.

Subsequent risk of cancer among women with a history of placental abruption

BACKGROUND

Placentation is characterized by extensive cell proliferation and neovascularization, which is similar to the processes observed in the development of cancer. Nonetheless, little is known about the relation between abnormal placentation, such as placental abruption, and cancer.

MATERIAL AND METHODS

Data on women with placental abruption in a singleton pregnancy between 1971 and 2005 (n = 7804) were collected from the Finnish Hospital Discharge Registry and the Finnish Medical Birth Registry. The cohort was then linked with the Finnish Cancer Registry records until the end of 2013. Standardized incidence ratios (SIRs) were calculated for different cancers by dividing the observed numbers of cancers by those expected. The expected numbers were based on national cancer incidence rates.

RESULTS

During follow-up, 597 cancers were found among women with a history of placental abruption. The overall risk of cancer was not increased (SIR 0.95, 95% CI 0.88-1.02). However, the history of placental abruption was associated with an increased risk of lung cancer (SIR 1.51, 95% CI 1.05-2.10) and thyroid cancer (SIR 1.47, 95% CI 1.04-2.02). A decreased risk was found for breast cancer (SIR 0.85, 95% CI 0.75-0.96). The risk of rectal cancer was also decreased, although these numbers were small (SIR 0.49, 95% CI 0.20-1.01).

CONCLUSIONS

Overall, the risk of lung cancer was increased, and the risk of breast cancer decreased, in women with a history of placental abruption. These observations can be explained to some extent by risk factors or risk markers for placental abruption. The increased risk of thyroid cancer may be explained by surveillance bias.

Placental Abruption and Child Mortality

BACKGROUND AND OBJECTIVES

Placental abruption causes asphyxia and leads to high perinatal mortality. Our objective was to study the overall mortality and causes of death among children born after placental abruption.

METHODS

Data on children born from singleton pregnancies complicated by placental abruption between 1987 and 2005 were collected from the Finnish Medical Birth Register, the Hospital Discharge Register, and the Cause-of-Death Register. A reference group consisted of children born from pregnancies without placental abruption. After excluding stillbirths, the final study sample comprised 3888 children born after placental abruption (index children) and 12 530 referent children. The main outcome measure was overall mortality.

RESULTS

By the end of 2013, there were 280 deaths among the index children and 107 deaths among the referent children. Compared with the referent children, the overall mortality among the index children was significantly increased (hazard ratio: 8.70; 95% confidence interval 6.96-10.90). During the neonatal period (0-27 days) the mortality was nearly 15-fold (14.8; 10.9-20.0), birth-related asphyxia being the leading cause of death (108; 34-341). The mortality remained high during days 28 to 365 (10.3; 4.83-21.8) and beyond 365 days (1.70; 1.03-2.79). Furthermore, the overall mortality was increased among the index children born at 32 to 36 + 6 gestational weeks (2.77; 1.54-4.98) and at ≥37 weeks (4.98; 3.54-6.99) and among children with a birth weight of 2500 g or more (5.94; 4.33-8.14).

CONCLUSIONS

The impact of abruption on offspring mortality extends far beyond the perinatal period. This is mainly due to birth-related asphyxia and prematurity-related consequences.

Evaluation of SEPs in asphyxiated newborns using a 4-electrode aEEG brain monitoring set-up

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Neonatal SEPs can be reliably detected using the 4-electrode aEEG monitoring setup.

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SEP is discernible in most fullterm newborns with 300 averages.

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Recording SEPs jointly with aEEG facilitates SEP assessment after birth asphyxia.

Objective

To evaluate the reliability of recording cortical somatosensory evoked potentials (SEPs) in asphyxiated newborns using the 4-electrode setup applied in routine long-term amplitude-integrated EEG (aEEG) brain monitoring and to assess the number of averages needed for reliably detecting the cortical responses.

Methods

We evaluated median nerve SEPs in 50 asphyxiated full-term newborns. The SEP interpretation (present or absent) from the original recordings with 21-electrodes and approximately 600 trials served as the reference. This was compared to SEP classification (absent, present, or unreliable) based on a reduced (300 or 150) number of averages, and to classification based on only four electrodes (F3, P3, F4, P4).

Results

Compared to the original classification, cortical SEPs were uniformly interpreted as present or absent in all 50 newborns with the 4-electrode setup and 600 averages. Reducing number of averages to 300 still resulted in correct SEP interpretation in 49/50 newborns with 21-electrode setup, and 46/50 newborns with 4-electrode setup.

Conclusions

Evaluation of early cortical neonatal SEPs is reliable from the 4-electrode setup commonly used in aEEG monitoring. SEP is discernible in most newborns with 300 averages.

Significance

Adding SEP into routine aEEG monitoring offers an additional tool for early neonatal neurophysiological evaluation.

Low Apgar scores at both one and five minutes are associated with long-term neurological morbidity

AIM

This study evaluated the associations between low Apgar scores at one and five minutes and long-term neurological impairments.

METHODS

This study used population-based data on 399,815 singletons born in Finland in 2004-2010 and multivariable logistic regression to examine any associations between low (0-3) and intermediate (4-6) Apgar scores and cerebral palsy, epilepsy, intellectual disability and sensorineural defects by the age of four years.

RESULTS

The odd ratios (OR) and 95% confidence intervals (95% CI) showed that low Apgar scores were associated with cerebral palsy at one and five minutes (ORs 2.08, 95% CI 1.32-3.26 and 5.19, 95% CI 3.06-8.80), epilepsy (ORs 1.62, 95% CI 1.13-2.33 and 4.79, 95% CI 3.03-7.56), and intellectual disability (ORs 2.46, 95% CI 1.45-4.16 and 6.21, 95% CI 3.33-11.58). Only a low five-minute Apgar score was associated with sensorineural defects (OR 3.13, 95% CI 1.95-5.02). Neurological impairment risks were increased by low Apgar scores at both one and five minutes (OR 11.1, 95% CI 8.6-14.5), but 90.3% of children with persistent low Apgar scores had no impairment.

CONCLUSION

Low one-minute and five-minute Apgar scores were associated with long-term neurological morbidity, especially when both scores were low.

Sensory-motor performance in seven-year-old children born extremely preterm

BACKGROUND

Children born preterm are prone to motor problems. Research on their motor performance has, however, rarely been integrated with sensory processing.

AIM

To examine sensory-motor performance in children born extremely preterm (EPT).

METHOD

In a longitudinal prospective cohort study, 49 EPT (born <28 gestational weeks; 32 boys and 17 girls) and 33 term-born (16 boys and 17 girls) children were assessed with six individual subtests from the Sensory Integration and Praxis Tests at the age of 7.0 to 7.3 years.

RESULTS

The rate of test z-scores indicating dysfunction [from -2 standard deviations (SD) to < -1 SD for mild and < -2 SD for moderate-to-severe] was significantly higher in EPT children than in term-born children in all the subtests. When comparing mean performance adjusted for gender and mother's education, EPT children performed worse than term-born children in Design Copying (z-score difference - 0.83; 95% confidence interval -1.32 to -0.34), Motor Accuracy (-0.82; -1.26 to -0.38), Postural Praxis (-0.95; -1.45 to -0.45), Manual Form Perception (-0.59; -1.12 to -0.06), and Finger Identification (-0.88; -1.45 to -0.31). Additional adjustment for Full-Scale Intelligence Quotient rendered difference in Manual Form Perception non-significant.

CONCLUSION

Seven-year-old EPT children perform worse than their term-born peers in tests for visual-motor, somatosensory, and motor planning performance.

Ocular Abnormalities in Transgenic Mice Harboring Mutations in the Type Ii Collagen Gene

PURPOSE

To characterize the morphological changes in the eyes of transgenic mice harboring different mutations in type II collagen gene to elucidate the function of this collagen in the eye, and to find out whether these animals could function as models for the human arthro-ophthalmopathies of the Kniest, Stickler and Wagner types.

METHODS

Three genetically engineered mouse lines representing two types of mutations in the triple-helical domain of type II collagen and their nontransgenic littermates used as controls were analyzed on day 18.5 embryonic development. After genotyping by polymerase chain reaction (PCR) and Southern hybridization the embryos were prepared for routine histology. Polarization microscopy was done on hyaluronidase-treated sections.

RESULTS

Histological analysis revealed several genotype-dependent abnormalities in the eyes of the transgenic mice. Most striking changes were observed in the vitreous architecture; in one line of mice the vitreous was tightly packed in the posterior region of the vitreous space with thick fibrils, empty cavities and dense membrane-like material. The other mutation resulted in reduced filament density of the vitreous. In the most severely affected phenotype the internal limiting membrane was detached from the retinal layers and was markedly thickened, and the posterior lens capsule was thickened. The anterior chamber was shallow or absent in all transgenic lines but was well formed in the normal animals. Changes were also observed in the lens, corneal and scleral structures.

CONCLUSIONS

The ocular changes observed in transgenic mice harboring mutations in type II collagen gene show similarities to the human ocular findings in Kniest dysplasia, and in Stickler and Wagner syndromes. We therefore propose that these animals could serve as models for systematic analysis of vitreoretinal degeneration and other abnormalities, as seen in these syndromes.

Mortality and causes of death among women with a history of placental abruption

INTRODUCTION

Women with a history of placental abruption have an increased later morbidity, but not much is known of the later mortality.

MATERIAL AND METHODS

Data on women with placental abruption (index cohort) between 1969 and 2005 (n = 7805) were collected from the Finnish Hospital Discharge Register and the Finnish Medical Birth Register. A matched reference cohort consisted of women without placental abruption (n = 23 523). The causes of death were retrieved from the Cause-of-Death Register. Cause-specific mortality was compared by hazard ratios (HR). Standardized mortality ratios were calculated to compare both cohorts with the general female population. The main outcome measure was subsequent mortality.

RESULTS

By the end of 2013 there were 395 deaths in the index cohort and 863 deaths in the reference cohort. The overall mortality was increased in the index cohort compared with the reference cohort [HR 1.39, 95% confidence interval (CI) 1.24-1.57]. The index cohort had an increased risk of death from respiratory tract malignancies (HR 1.72, 95% CI 1.05-2.82), alcohol-related causes (HR 1.84, 95% CI 1.25-2.72), and external causes (HR 1.63, 95% CI 1.19-2.22), especially suicide (HR 1.71, 95% CI 1.07-2.74). The mortality from cardiovascular diseases did not differ. The standardized mortality ratio was increased in the index cohort compared with the general Finnish female population (HR 1.13, 95% CI 1.02-1.24), especially for respiratory tract malignancies (HR 1.79, 95% CI 1.16-2.64). The index cohort women tended to die younger than referent women (p < 0.001).

CONCLUSIONS

Overall mortality among women with a history of placental abruption is increased. These women tend to die younger than referent women do.

Neonatal somatosensory evoked potentials persist during hypothermia

AIM

Treatment with therapeutic hypothermia has challenged the use of amplitude-integrated electroencephalography in predicting outcomes after perinatal asphyxia. In this study, we assessed the feasibility and gain of somatosensory evoked potentials (SEP) during hypothermia.

METHODS

This retrospective study comprised neonates from 35 + 6 to 42 + 2 gestational weeks and treated for asphyxia or hypoxic-ischaemic encephalopathy at Helsinki University Hospital between 14 February 2007 and 23 December 2009. This period was partly before the introduction of routine therapeutic hypothermia, which enabled us to include normothermic neonates who would these days receive hypothermia treatment. We analysed SEPs from 47 asphyxiated neonates and compared the results between 23 normothermic and 24 hypothermic neonates.

RESULTS

Our data showed that hypothermia led to SEP latencies lengthening by a few milliseconds, but the essential gain for predicting outcomes by SEPs was preserved during hypothermia. Of the 24 hypothermic neonates, bilaterally absent SEPs were associated with poor outcome in 2/2 neonates, normal SEPs were associated with good outcomes in 13/15 neonates and 5/7 neonates with unilaterally absent or grossly delayed SEPs had a poor outcome.

CONCLUSION

Our findings indicated that SEPs were a reliable tool for evaluating the somatosensory system in asphyxiated neonates in both normothermic and hypothermic conditions.

Evoked potentials recorded during routine EEG predict outcome after perinatal asphyxia

OBJECTIVE

To evaluate the added value of somatosensory (SEPs) and visual evoked potentials (VEPs) recorded simultaneously with routine EEG in early outcome prediction of newborns with hypoxic-ischemic encephalopathy under modern intensive care.

METHODS

We simultaneously recorded multichannel EEG, median nerve SEPs, and flash VEPs during the first few postnatal days in 50 term newborns with hypoxic-ischemic encephalopathy. EEG background was scored into five grades and the worst two grades were considered to indicate poor cerebral recovery. Evoked potentials were classified as absent or present. Clinical outcome was determined from the medical records at a median age of 21months. Unfavorable outcome included cerebral palsy, severe mental retardation, severe epilepsy, or death.

RESULTS

The accuracy of outcome prediction was 98% with SEPs compared to 90% with EEG. EEG alone always predicted unfavorable outcome when it was inactive (n=9), and favorable outcome when it was normal or only mildly abnormal (n=17). However, newborns with moderate or severe EEG background abnormality could have either favorable or unfavorable outcome, which was correctly predicted by SEP in all but one newborn (accuracy in this subgroup 96%). Absent VEPs were always associated with an inactive EEG, and an unfavorable outcome. However, presence of VEPs did not guarantee a favorable outcome.

CONCLUSIONS

SEPs accurately predict clinical outcomes in newborns with hypoxic-ischemic encephalopathy and improve the EEG-based prediction particularly in those newborns with severely or moderately abnormal EEG findings.

SIGNIFICANCE

SEPs should be added to routine EEG recordings for early bedside assessment of newborns with hypoxic-ischemic encephalopathy.

Lack of Cortical Correlates of Response Inhibition in 6-Year-Olds Born Extremely Preterm - Evidence from a Go/NoGo Task in Magnetoencephalographic Recordings

Children born extremely preterm (EPT) may have difficulties in response inhibition, but the neural basis of such problems is unknown. We recorded magnetoencephalography (MEG) during a somatosensory Go/NoGo task in 6-year-old children born EPT (n = 22) and in children born full term (FT; n = 21). The children received tactile stimuli randomly to their left little (target) and index (non-target) finger and were instructed to squeeze a soft toy with the opposite hand every time they felt a stimulus on the little finger. Behaviorally, the EPT children performed worse than the FT children, both in responding to the target finger stimulation and in refraining from responding to the non-target finger stimulation. In MEG, after the non-target finger stimulation (i.e., during the response inhibition), the sensorimotor alpha oscillation levels in the contralateral-to-squeeze hemisphere were elevated in the FT children when compared with a condition with corresponding stimulation but no task (instead the children were listening to a story and not attending to the fingers). This NoGo task effect was absent in the EPT children. Further, in the sensorimotor cortex contralateral to the tactile stimulation, the post-stimulus suppression was less pronounced in the EPT than FT children. We suggest that the missing NoGo task effect and lower suppression of sensorimotor oscillations are markers of deficient functioning of the sensorimotor networks in the EPT children.

Atypical sensory processing is common in extremely low gestational age children

AIM

Atypical sensory processing is common in children born extremely prematurely. We investigated sensory processing abilities in extremely low gestational age (ELGA) children and analysed associated neonatal risk factors, neuroanatomical findings and neurodevelopmental outcome.

METHODS

We carried out a prospective study of 44 ELGA children, including 42 who had undergone brain magnetic resonance imaging (MRI) at term-equivalent age, when they were 2 years of corrected age. Their sensory processing abilities were assessed with the Infant/Toddler Sensory Profile questionnaire and their neurodevelopmental with a structured Hempel neurological examination, Griffiths Mental Developmental Scales and Bayley Scales of Infant and Toddler Development Third Edition.

RESULTS

Sensory profiles were definitely or probably atypical (<-1 SD) in half of the ELGA children, and the most common behavioural pattern was low registration (23%). Sensation seeking was associated with abnormalities in grey and/or white matter in the brain MRI (p < 0.01). Atypical oral sensory processing was associated with surgical closure of the patent ductus arteriosus (p = 0.02, adjusted p < 0.01).

CONCLUSION

Atypical sensory processing in ELGA children was common, and children with neonatal neuroanatomical lesions tended to present specific behavioural responses to sensory stimuli. Surgical closure of the patent ductus arteriosus may predispose infants to feeding problems due to atypical oral sensory processing.

Mother-child interaction is associated with neurocognitive outcome in extremely low gestational age children

Early mother-child interaction is one of the factors suggested to have an impact on neurocognitive development of extremely low gestational age (ELGA) children. Our aim was to examine associations of mother-child interaction with neurocognitive outcome, neurological impairments and neonatal brain injuries in ELGA children. A prospective study of 48 ELGA children, born before 28 gestational weeks (26.3 ± 1.2 weeks, birth weight 876 g ± 194 g), and 16 term controls. Brain MRI was performed at term-equivalent age. At two years of corrected age, the mother-child interaction was assessed in a structured play situation using the Erickson Scales and Mutually Responsive Orientation Scales. Neurocognitive outcome was assessed with Griffiths Mental Developmental Scales (GMDS) and Bayley Scales of Infant and Toddler Development - Third Edition (BSID-III) and with Hempel neurological examination. Among ELGA children, higher quality of dyadic relationship and maternal sensitivity, responsiveness, and supportiveness were associated with positive neurocognitive outcome measured both with GMDS and BSID-III (adjusted p < 0.05). This association remained after adjusting for mother's educational level. Neurological impairments at two years, white matter or gray matter abnormalities in MRI at term-equivalent age, and grade III-IV intraventricular hemorrhage during the neonatal period were not associated with mother-child interaction. This study emphasizes the importance of the quality of mother-child interaction after extremely preterm birth for neurocognitive development. Neonatal brain injury and neurological impairments were not associated with worse parent-child interaction after two years.

Novel features of early burst suppression predict outcome after birth asphyxia

Burst suppression patterns in the electroencephalogram are a reliable marker of recent severe brain insult. Here we analyze statistical properties of bursts occurring in 20 electroencephalographic recordings acquired from hypothermic asphyxic newborns in the hours immediately following birth. We show that the distributions of burst area and duration in these acute data predict later clinical outcome in both structural neuroimaging and neurodevelopment. Our findings indicate the first early electroencephalographic metrics that offer outcome prediction in asphyxic neonates undergoing hypothermia treatment.

Novel features of early burst suppression predict outcome after birth asphyxia

Burst suppression patterns in the electroencephalogram are a reliable marker of recent severe brain insult. Here we analyze statistical properties of bursts occurring in 20 electroencephalographic recordings acquired from hypothermic asphyxic newborns in the hours immediately following birth. We show that the distributions of burst area and duration in these acute data predict later clinical outcome in both structural neuroimaging and neurodevelopment. Our findings indicate the first early electroencephalographic metrics that offer outcome prediction in asphyxic neonates undergoing hypothermia treatment.

Drug effects on endogenous brain activity in preterm babies

BACKGROUND

Animal experiments have suggested that the quality of the early intermittent brain activity is important for shaping neuronal connectivity during developmental phase that corresponds to early prematurity. This is a pilot study aiming to assess whether spontaneous activity transients (SAT) in the early preterm babies are affected by drugs that are routinely used in neonatal intensive care.

METHODS

We collected retrospectively seventeen EEG recordings (15 babies, conceptional age 26-33weeks, no brain lesions) that were divided into groups according to drug administration at the time of EEG: phenobarbital, fentanyl, theophylline, and controls. SATs were extracted from the EEG for further analysis with several advanced time-series analysis paradigms.

RESULTS

The visual appearance of SATs was unaffected by drugs. Phenobarbital reduced the total power of the SAT events. Both fentanyl and phenobarbital reduced the length of SATs, and enhanced the oscillations at higher frequencies. Theophylline reduced the oscillatory activity at middle frequencies during SAT, but enhanced oscillations at higher frequencies during time-period prior to SAT.

CONCLUSIONS

Our findings suggest, that (i) all drugs examined affect brain activity in ways that are not seen in the visual EEG interpretation, and that (ii) both acute and long term (i.e. developmental) effects of these drugs on brain may warrant more attention as a part of optimizing preterm neurological care.