Risk factors for neonatal seizures in very low birthweight infants: population-based survey

Current Evidence: Seizures in Extremely Low Gestational Age Newborns (ELGANs)

Extremely low gestational age newborns (ELGANs) are born at or below 28 weeks of gestational age. Despite improved obstetric care, the incidence of preterm birth continues to rise in advanced countries. Preterm birth remains a major cause of infant mortality, and for infants who survive, neonatal seizures are a significant predictor of later neurologic morbidity. However, little is known about risk factors for neonatal seizures in ELGANs. Understanding the association between neonatal seizures and the development of other neurologic disorders is important given the increasing prevalence of ELGANs. Identifying risk factors that contribute to the development of neonatal seizures in ELGANs may offer insights into novel mechanisms of epileptogenesis in the developing brain and improvements in the prevention or treatment of seizures in preterm infants, including ELGANs. In this literature review, we outline the limitations of epidemiologic studies of neonatal seizures in ELGANs and discuss risk factors for neonatal seizures.

Current Status and Associated Factors of Post-Hemorrhagic Hydrocephalus in Infants of 22 to 28 Weeks Gestation With Severe Intraventricular Hemorrhage in Korea: A Nationwide Cohort Study

BACKGROUND

Post-hemorrhagic hydrocephalus (PHH), a common complication of severe intraventricular hemorrhage (IVH) in very low birth weight (BW) infants, is associated with significant morbidity and poor neurological outcomes. The objective of this study was to assess the current status of PHH and analyze the risk factors associated with the necessity of treatment for PHH in infants born between 22 and 28 weeks of gestation, specifically those with severe IVH (grade 3 or 4).

METHODS

The analysis was conducted on 1,097 infants who were born between 22-28 gestational weeks and diagnosed with severe IVH, using data from the Korean Neonatal Network. We observed that the prevalence of PHH requiring treatment was 46.3% in infants with severe IVH.

RESULTS

Higher rates of mortality, transfer during admission, cerebral palsy, and ventriculoperitoneal shunt after discharge were higher in infants with PHH than in those without PHH. PHH in severe IVH was associated with a higher rate of pulmonary hemorrhage, seizures, and IVH grade 4 in the entire cohort. In addition, it was associated with a lower rate of small for gestational age and chorioamnionitis. In the subgroup analysis, high BW, outborn status, pulmonary hemorrhage, seizure, sepsis, and IVH grade 4 were associated with a higher incidence of PHH between 22 and 25 gestational weeks (GW). In infants born between 26 and 28 GW, a higher incidence of PHH was associated with seizures and IVH grade 4.

CONCLUSION

It is necessary to maintain meticulous monitoring and neurological intervention for infants with PHH not only during admission but also after discharge. In addition, identifying the clinical factors that increase the likelihood of developing PHH from severe IVH is crucial.

Communal Poverty Is a Significant Risk Factor for Neonatal Seizures

INTRODUCTION

Neonatal seizures (NS) are a severe condition with significant mortality and long-term morbidity. This study aims to identify risk factors for NS in a racially or ethnically diverse population in Israel.

METHODS

This is a case-control study. The cases were all newborns born between 2001 and 2019 at Emek Medical Center in Israel and admitted with NS. Two healthy controls born in the same period were matched for each case. Demographic, maternal, and neonatal variables were abstracted from the electronic medical files.

RESULTS

A total of 139 cases were matched with 278 controls. Residing in a town with lower socioeconomic status (SES), primiparity and abnormal prenatal ultrasound were significantly associated with NS. Prematurity, assisted delivery, a lower birthweight, being small for gestational age, and lower Apgar score were also associated with NS. In two different multivariable regression models, lower SES (odds ratio [OR] = 4.07) and Arab race/ethnicity (OR = 2.66) were risk factors for NS. Other significant risk factors in the multivariable regression models included an assisted mode of delivery (OR = 2.33), prematurity (OR = 2.27), and a 5-minute Apgar score below 7 (OR = 54.1).

DISCUSSION

Communal poverty, as reflected by lower SES of towns of residence, was found to be a stronger risk factor than race or ethnicity, for NS. More studies should focus on social class, as a risk factor for maternal and neonatal adverse outcomes. As SES is a modifiable variable every effort should be invested in fighting communal poverty and improving the SES of impoverished towns and population.

Levetiracetam versus Phenobarbital for Neonatal Seizures: A Retrospective Cohort Study

BACKGROUND

Although phenobarbital (PB) is commonly used as a first-line antiseizure medication (ASM) for neonatal seizures, in 2015 we chose to replace it with levetiracetam (LEV), a third-generation ASM. Here, we compared the safety and efficacy of LEV and PB as first-line ASM, considering the years before and after modifying our treatment protocol.

METHODS

We conducted a retrospective cohort study of 108 neonates with electroencephalography (EEG)-confirmed seizures treated with first-line LEV or PB in 2012 to 2020.

RESULTS

First-line ASM was LEV in 33 (31%) and PB in 75 (69%) neonates. The etiology included acute symptomatic seizures in 69% of cases (30% hypoxic-ischemic encephalopathy, 32% structural vascular, 6% infectious, otherwise metabolic) and neonatal epilepsy in 22% (5% structural due to brain malformation, 17% genetic). Forty-two of 108 (39%) neonates reached seizure freedom following first-line therapy. Treatment response did not vary by first-line ASM among all neonates, those with acute symptomatic seizures, or those with neonatal-onset epilepsy. Treatment response was lowest for neonates with a higher seizure frequency, particularly for those with status epilepticus versus rare seizures (P < 0.001), irrespective of gestational age, etiology, or EEG findings. Adverse events were noted in 22 neonates treated with PB and in only one treated with LEV (P < 0.001).

CONCLUSIONS

Our study suggests a potential noninferiority and a more acceptable safety profile for LEV, which may thus be a reasonable option as first-line ASM for neonatal seizures in place of PB. Treatment should be initiated as early as possible since higher seizure frequencies predispose to less favorable responses.

Optical Monitoring in Neonatal Seizures

BACKGROUND

Neonatal seizures remain a significant cause of morbidity and mortality worldwide. The past decade has resulted in substantial progress in seizure detection and understanding the impact seizures have on the developing brain. Optical monitoring such as cerebral near-infrared spectroscopy (NIRS) and broadband NIRS can provide non-invasive continuous real-time monitoring of the changes in brain metabolism and haemodynamics.

AIM

To perform a systematic review of optical biomarkers to identify changes in cerebral haemodynamics and metabolism during the pre-ictal, ictal, and post-ictal phases of neonatal seizures.

METHOD

A systematic search was performed in eight databases. The search combined the three broad categories: (neonates) AND (NIRS) AND (seizures) using the stepwise approach following PRISMA guidance.

RESULTS

Fifteen papers described the haemodynamic and/or metabolic changes observed with NIRS during neonatal seizures. No randomised controlled trials were identified during the search. Studies reported various changes occurring in the pre-ictal, ictal, and post-ictal phases of seizures.

CONCLUSION

Clear changes in cerebral haemodynamics and metabolism were noted during the pre-ictal, ictal, and post-ictal phases of seizures in neonates. Further studies are necessary to determine whether NIRS-based methods can be used at the cot-side to provide clear pathophysiological data in real-time during neonatal seizures.

Towards integrative neuromonitoring of the surgical newborn: A systematic review

BACKGROUND

The altered neurodevelopment of children operated on during the neonatal period might be due to peri-operative changes in the homeostasis of brain perfusion. Monitoring of vital signs is a standard of care, but it does not usually include monitoring of the brain.

OBJECTIVES

To evaluate methods of monitoring the brain that might be of value. We also wanted to clarify if there are specific risk factors that result in peri-operative changes and how this might be evaluated.

DESIGN

Systematic review.

DATA SOURCES

A structured literature search was performed in MEDLINE in Ovid, Embase, Cochrane CENTRAL, Web of Science and Google Scholar.

ELIGIBILITY CRITERIA

Studies in neonates who received peri-operative neuromonitoring were eligible for inclusion; studies on neurosurgical procedures or cardiac surgery with cardiopulmonary bypass and/or deep hypothermia cardiac arrest were excluded.

RESULTS

Nineteen of the 24 included studies, totalling 374 infants, reported the use of near-infrared spectroscopy. Baseline values of cerebral oxygenation greatly varied (mean 53 to 91%) and consequently, no coherent results were found. Two studies found a correlation between cerebral oxygenation and mean arterial blood pressure. Five studies, with in total 388 infants, used (amplitude-integrated) electro-encephalography to study peri-operative brain activity. Overall, the brain activity decreased during anaesthesia and epileptic activity was more frequent in the peri-operative phase. The association between intra-operative cerebral saturation or activity and neuro-imaging abnormalities and/or neurodevelopmental outcome was investigated in six studies, but no association was found.

CONCLUSION

Neuromonitoring with the techniques currently used will neither help our understanding of the altered neonatal pathophysiology, nor enable early detection of deviation from the norm. The modalities lack specificity and are not related to clinical (long-term) outcome or prognosis. Accordingly, we were unable to draw up a monitoring guideline.

Perinatal factors associated with amplitude-integrated electroencephalography abnormalities in preterm infants on the first day of life

OBJECTIVE

Evaluate the association between perinatal factors and amplitude-integrated electroencephalogram abnormalities in preterm infants on the first day of life.

METHODS

This was a cross-sectional study of 60 infants with gestational age between 23 and 32 weeks, without malformations. Infants were continuously monitored by amplitude-integrated electroencephalogram on the first day of life, for at least 3h. The tracings were recorded and analyzed in each column for the following: burst-suppression pattern, sleep-wake cycle, and amplitude of the lower margin (<3μV or <5μV). The association of maternal complications, mode of delivery, birth weight, gestational age, neonatal sex, resuscitation procedures, hypothermia on admission, and the Score for Neonatal Acute Physiology, Perinatal Extension, Version II [SNAPPE-II]) with amplitude-integrated electroencephalogram alterations was assessed by multiple logistic regression.

RESULTS

A discontinuous pattern occurred in 65% of infants, and a continuous pattern occurred in 23%. The burst-suppression pattern was associated with vaginal delivery (OR: 7.6; 95% CI: 1.1-53.1) and SNAPPE-II≥40 (OR: 13.1; 95% CI: 1.8-95.1). A lower margin of the amplitude-integrated electroencephalogram of <3μV was also associated with SNAPPE-II≥40 (OR: 10.6, 95% CI: 2.3-49.2), while a value <5μV was associated with lower GA (OR: 0.51, 95% CI: 0.34-0.76). There were no associations between the perinatal variables and the absence of a sleep-wake cycle in amplitude-integrated electroencephalogram recordings on the first day of life.

CONCLUSION

Biological variables and clinical severity are associated with electroencephalographic characteristics of preterm infants on the first day of life and should be considered in clinical practice when amplitude-integrated electroencephalogram is performed.

Neonatal seizures in preterm infants: A systematic review of mortality risk and neurological outcomes from studies in the 2000's

INTRODUCTION

Neonatal seizures (NS) are associated with increased mortality and risk of cerebral palsy, epilepsy and intellectual disability. We performed a systematic review with the primary objective to delineate the rate of these outcomes following NS in preterm infants from studies published in the 2000's and the secondary objective to identify risk factors.

METHODS

Inclusion criteria: original articles published between 1/1/2000 and 12/31/2018, written in English, evaluating newborns ≤37 weeks of gestational age and suffering from NS, in which at least one of these was evaluated: epilepsy, cerebral palsy, intellectual disability/developmental delay, normal outcome, death.

RESULTS

Twenty-two papers were selected and all were observational, with a retrospective design in 15. Three were population-based and twenty-one have a comparison. It has been found a 22-80 % of mortality, 11.3-38.9 % of epilepsy, 12-84.6 % of cerebral palsy, and 20-42.7 % of intellectual disability/developmental delay rate. An increased risk for all outcomes considered was reported. Risk factors for specific outcomes were provided by a minority of studies. However, inclusion criteria, definition of NS and measured outcomes, follow-up lengths differed considerably between studies.

DISCUSSION

Results of the selected studies are only partially comparable or generalizable because of differences in study design. They have a risk for potential biases, although they provide (if analyzed) readily available prognostic factors, easy to apply in clinical practice. Prospective, population-based studies with EEG-defined NS are warranted in order to produce evidence-based guidance for management of preterm newborns with seizures.

Lack of response to treatment with levetiracetam in extreme preterm infants with seizures

OBJECTIVE

The aim of this study was to evaluate the effectiveness of monotherapy with levetiracetam (LEV) in achieving seizure cessation in a retrospective cohort of extreme preterm infants with seizures.

STUDY DESIGN

Charts of infants with a diagnosis of neonatal seizures admitted to the NICU between 2013 and 2017 were reviewed. Seizures were diagnosed using continuous video electroencephalography. All infants were initially started on LEV and reached a dose of 80 mg/kg/day. Other ASMs were added to LEV if seizures continued after 2 days. Data on additional clinical variables were collected for each infant.

RESULT

Sixty-one infants born <28 weeks of gestation met inclusion criteria. Seventy-four percent of patients did not respond to LEV monotherapy and required additional medications.

CONCLUSIONS

LEV monotherapy stopped seizures in only a small portion of cases.

How Early Can a Seizure Happen? Pathophysiological Considerations of Extremely Premature Infant Brain Development

Seizures in neonates represent a neurologic emergency requiring prompt recognition, determination of etiology, and treatment. Yet, the definition and identification of neonatal seizures remain challenging and controversial, in part due to the unique physiology of brain development at this life stage. These issues are compounded when considering seizures in premature infants, in whom the complexities of brain development may engender different clinical and electrographic seizure features at different points in neuronal maturation. In extremely premature infants (< 28 weeks gestational age), seizure pathophysiology has not been explored in detail. This review discusses the physiological and structural development of the brain in this developmental window, focusing on factors that may lead to seizures and their consequences at this early time point. We hypothesize that the clinical and electrographic phenomenology of seizures in extremely preterm infants reflects the specific pathophysiology of brain development in that age window.

Outcome in preterm infants with seizures

Most neonatal seizures in preterm newborns are of acute symptomatic origin with a prevalence higher than in full-term infants. To date, recommendations for management of seizures in preterm newborns are scarce and do not differ from those in full-term newborns. Mortality in preterm newborns with seizures has significantly declined over the last decades, from figures of 84%-94% in the 1970s and 1980s to 22%-45% in the last years. However, mortality is significantly higher in those with a birth weight<1000g and a gestational age<28 weeks. Seizures are a strong predictor of unfavorable outcomes, including not only cerebral palsy, epilepsy, and intellectual disability, but also vision, hearing impairment, and microcephaly. The majority of patients with developmental delay are severely affected and this is usually associated with cerebral palsy. Furthermore, the incidence of epilepsy after neonatal seizures seems to be lower in preterm than in full-term infants but the risk is approximately 40 times greater than in the general population. Clinical studies cannot disentangle the specific and independent contributions of seizure-induced functional changes and the role of etiology and brain damage severity in determining the long-term outcomes in these newborns.

Symptomatic seizures in preterm newborns: a review on clinical features and prognosis

Neonatal seizures are the most common neurological event in newborns, showing higher prevalence in preterm than in full-term infants. In the majority of cases they represent acute symptomatic phenomena, the main etiologies being intraventricular haemorrhage, hypoxic-ischemic encephalopathy, central nervous system infections and transient metabolic derangements.Current definition of neonatal seizures requires detection of paroxysmal EEG-changes, and in preterm newborns the incidence of electrographic-only seizures seems to be particularly high, further stressing the crucial role of electroencephalogram monitoring in this population. Imaging work-up includes an integration of serial cranial ultrasound and brain magnetic resonance at term-equivalent age. Unfavourable outcomes following seizures in preterm infants include death, neurodevelopmental impairment, epilepsy, cerebral palsy, hearing and visual impairment. As experimental evidence suggests a detrimental role of seizures per se in determining subsequent outcome, they should be promptly treated with the aim to reduce seizure burden and long-term disabilities. However, neonatal seizures show low response to conventional anticonvulsant drugs, and this is even more evident in preterm newborns, due to intrinsic developmental factors. As a consequence, as literature does not provide any specific guidelines, due to the lack of robust evidence, off-label medications are often administered in clinical practice.

Acute symptomatic neonatal seizures in preterm neonates: etiologies and treatments

Acute symptomatic neonatal seizures in preterm newborns are a relevant clinical challenge due to the presence of many knowledge gaps. Etiology-wise, acute symptomatic seizures have an age-specific epidemiology, with intraventricular hemorrhage and its complications representing the first cause in extremely and very preterm neonates, whereas other etiologies have similar occurrence rates as in full-term infants. Specific treatment strategies for the premature neonates are not yet available. Studies suggest a similarly low response rate with even more unfavorable prognosis than in full-term infants. Pharmacodynamic and pharmacokinetic changes are likely under way during the preterm period, with the potential to affect both effectiveness and safety of antiepileptic drugs in these patients. However, due to the lack of clear evidence to guide prioritization of second-line drugs, off-label medications are frequently indicated by review papers and flow-charts, and are prescribed in clinical practice. We therefore conclude by exploring potential future lines of research.

Seizures in Preterm Neonates: A Multicenter Observational Cohort Study

BACKGROUND

The purpose of this study was to characterize seizures among preterm neonates enrolled in the Neonatal Seizure Registry, a prospective cohort of consecutive neonates with seizures at seven pediatric centers that follow the American Clinical Neurophysiology Society's neonatal electroencephalography monitoring guideline.

STUDY DESIGN

Of 611 enrolled neonates with seizures, 92 (15%) were born preterm. Seizure characteristics were evaluated by gestational age at birth for extremely preterm (<28 weeks, N = 18), very preterm (28 to <32 weeks, N = 18), and moderate to late preterm (32 to <37 weeks, N = 56) and compared with term neonates.

RESULTS

Hypoxic-ischemic encephalopathy (33%) and intracranial hemorrhage (27%) accounted for the etiology in more than half of preterm neonates. Hypothermia therapy was utilized in 15 moderate to late preterm subjects with encephalopathy. The presence of subclinical seizures, monotherapy treatment failure, and distribution of seizure burden (including status epilepticus) was similar in preterm and term neonates. However, exclusively subclinical seizures occurred more often in preterm than term neonates (24% vs 14%). Phenobarbital was the most common initial medication for all gestational age groups, and failure to respond to an initial loading dose was 63% in both preterm and term neonates. Mortality was similar among the three preterm gestational age groups; however, preterm mortality was more than twice that of term infants (35% vs 15%).

CONCLUSIONS

Subclinical seizures were more common and mortality was higher for preterm than term neonates. These data underscore the importance of electroencephalographic monitoring and the potential for improved management in preterm neonates.

Pharmacologic Management of Neonatal Seizures

Seizures are most often the only sign of a central nervous dysfunction in the neonate. Neonatal seizures are a symptom of a specific disease entity. The search for a cause of neonatal seizures should focus on perinatal history or acute metabolic changes in the neonate. There are four classifications of neonatal seizures: clonic, tonic, myoclonic, and subtle. Simultaneous electroencephalogram and video recording are tools to assist the practitioner in the evaluation of difficult-to-assess subtle behaviors. Although many seizures may be prevented by careful attention to metabolic changes and the neonate's overall condition, those that cannot be prevented may require pharmacologic treatment. First-generation antiepileptic drugs such as phenobarbital and phenytoin are still the first and second lines of therapy, even as questions concerning their limited clinical effectiveness and concern for potential neurotoxicity continue.

Could cord blood cell therapy reduce preterm brain injury?

Major advances in neonatal care have led to significant improvements in survival rates for preterm infants, but this occurs at a cost, with a strong causal link between preterm birth and neurological deficits, including cerebral palsy (CP). Indeed, in high-income countries, up to 50% of children with CP were born preterm. The pathways that link preterm birth and brain injury are complex and multifactorial, but it is clear that preterm birth is strongly associated with damage to the white matter of the developing brain. Nearly 90% of preterm infants who later develop spastic CP have evidence of periventricular white matter injury. There are currently no treatments targeted at protecting the immature preterm brain. Umbilical cord blood (UCB) contains a diverse mix of stem and progenitor cells, and is a particularly promising source of cells for clinical applications, due to ethical and practical advantages over other potential therapeutic cell types. Recent studies have documented the potential benefits of UCB cells in reducing brain injury, particularly in rodent models of term neonatal hypoxia–ischemia. These studies indicate that UCB cells act via anti-inflammatory and immuno-modulatory effects, and release neurotrophic growth factors to support the damaged and surrounding brain tissue. The etiology of brain injury in preterm-born infants is less well understood than in term infants, but likely results from episodes of hypoperfusion, hypoxia–ischemia, and/or inflammation over a developmental period of white matter vulnerability. This review will explore current knowledge about the neuroprotective actions of UCB cells and their potential to ameliorate preterm brain injury through neonatal cell administration. We will also discuss the characteristics of UCB-derived from preterm and term infants for use in clinical applications.

Epidemiology and aetiology of neonatal seizures

Neonatal seizures constitute the most frequent and distinctive neurological symptom in the neonatal period. Seizures in the neonatal period differ considerably from those observed later in life with respect to their aetiological profile and clinical presentation. In addition, the aetiological profile in preterm infants is different from that seen in term infants. Hypoxic-ischaemic encephalopathy is the most frequent cause of neonatal seizures in term babies followed by focal ischaemia (stroke), cerebral malformations and metabolic disturbances. In preterm neonates, intraventricular haemorrhage and infections cause most of the seizures reported in this group. Better neuroimaging techniques have reduced the number of undiagnosed cases, and the institution of newer neuroprotective strategies has influenced the outcome.

Investigations for neonatal seizures

Seizures during the neonatal period are always medical emergencies. Apart from the need for rapid anticonvulsive treatment, the underlying condition is often not immediately obvious. In the search for the correct diagnosis, a thorough history, clinical examination, laboratory work-up, neurophysiological and neuroradiological investigations are all essential. A close collaboration between neonatologists, neuropaediatricians, laboratory specialists, neurophysiologists and radiologists facilitates the adequate care of the infant.

Outcome following neonatal seizures

Neonatal seizures are the most common manifestation of neurological disorders in the newborn period and an important determinant of outcome. Overall, for babies born at full term, mortality following seizures has improved in the last decade, typical current mortality rates being 10% (range: 7-16%), down from 33% in reports from the 1990s. By contrast, the prevalence of adverse neurodevelopmental sequelae remains relatively stable, typically 46% (range: 27-55%). The strongest predictors of outcome are the underlying cause, together with the background electroencephalographic activity. In preterm babies, for whom the outlook tends to be worse as background mortality and disability are high, seizures are frequently associated with serious underlying brain injury and therefore subsequent impairments. When attempting to define the prognosis for a baby with neonatal seizures, we propose a pathway involving history, examination, and careful consideration of all available results (ideally including brain magnetic resonance imaging) and the response to treatment before synthesizing the best estimate of risk to be conveyed to the family.

Mortality risk after neonatal seizures in very preterm newborns

We analyzed clinical and instrumental data of 403 consecutive newborns with gestational age from 24 to 32 weeks, admitted to the University-Hospital of Parma between January 2000 and December 2007, to evaluate the possible relationship between neonatal mortality and occurrence of neonatal seizures in very preterm newborns. Seventy-four subjects died during hospital stay. Seizures were present in 35 neonates, in whom the mortality rate was 37.1%. Multivariate analysis revealed that birth-weight <1000 g (odds ratio: 4.48; 95% confidence interval: 1.47-13.68; P < .01), cardiopulmonary resuscitation (odds ratio: 5.35; 95% confidence interval: 1.19-23.98; P = .02), and moderately and severely abnormal cerebral ultrasound scan findings (odds ratio: 2.48; 95% confidence interval: 1.02-6.05; P < .04; odds ratio: 9.56; 95% confidence interval: 3.45-26.51; P < .01, respectively) were related to the in-hospital mortality but not the presence of neonatal seizures. Our study suggests that neonatal seizures alone are not an independent risk factor for early death in very preterm newborns.

Seizures in extremely low birth weight infants are associated with adverse outcome

OBJECTIVE

To examine risk factors for neonatal clinical seizures and to determine the independent association with death or neurodevelopmental impairment (NDI) in extremely low birth weight (ELBW) infants.

STUDY DESIGN

A total of 6499 ELBW infants (401-1000 g) surviving to 36 weeks postmenstrual age (PMA) were included in this retrospective study. Unadjusted comparisons were performed between infants with (n = 414) and without (n = 6085) clinical seizures during the initial hospitalization. Using multivariate logistic regression modeling, we examined the independent association of seizures with late death (after 36 weeks PMA) or NDI after controlling for multiple demographic, perinatal, and neonatal variables.

RESULTS

Infants with clinical seizures had a greater proportion of neonatal morbidities associated with poor outcome, including severe intraventricular hemorrhage, sepsis, meningitis, and cystic periventricular leukomalacia (all P < .01). Survivors were more likely to have NDI or moderate-severe cerebral palsy at 18 to 22 months corrected age (both P < .01). After adjusting for multiple confounders, clinical seizures remained significantly associated with late death or NDI (odds ratio, 3.15; 95% CI, 2.37-4.19).

CONCLUSION

ELBW infants with clinical seizures are at increased risk for adverse neurodevelopmental outcome, independent of multiple confounding factors.

When it comes to GABAergic responses and neonatal seizures--sex matters!

Dissociated Gender-Specific Effects of Recurrent Seizures on GABA Signaling in CA1 Pyramidal Neurons: Role of GABAA Receptors. Galanopoulou AS. J Neurosci 2008;28(7):1557–1567. Early in development, the depolarizing GABAAergic signaling is needed for normal neuronal differentiation. It is shown here that hyperpolarizing reversal potentials of GABAAergic post-synaptic currents ( EGABA) appear earlier in female than in male rat CA1 pyramidal neurons because of increased potassium chloride cotransporter 2 (KCC2) expression and decreased bumetanide-sensitive chloride transport in females. Three episodes of neonatal kainic acid-induced status epilepticus (3KA-SE), each elicited at postnatal days 4 (P4)–P6, reverse the direction of GABAAergic responses in both sexes. In males, 3KA-SE trigger a premature appearance of hyperpolarizing GABAAergic signaling at P9, instead of P14. This is driven by an increase in KCC2 expression and decrease in bumetanide-sensitive chloride cotransport. In 3KA-SE females, EGABA transiently becomes depolarizing at P8–P13 because of increase in the activity of a bumetanide-sensitive NKCC1 (sodium potassium chloride cotransporter 1)-like chloride cotransporter. However, females regain their hyperpolarizing GABAAergic signaling at P14 and do not manifest spontaneous seizures in adulthood. In maternally separated stressed controls, a hyperpolarizing shift in EGABA was observed in both sexes, associated with decreased bumetanide-sensitive chloride cotransport, whereas KCC2 immunoreactivity was increased in males only. GABAA receptor blockade at the time of 3KA-SE or maternal separation reversed their effects on EGABA. These data suggest that the direction of GABAA-receptor signaling may be a determining factor for the age- and sex-specific effects of prolonged seizures in the hippocampus, because they relate to normal brain development and possibly epileptogenesis. These effects differ from the consequences of severe stress.

Neonatal seizures: an update on mechanisms and management

The lifespan risk of seizures is highest in the neonatal period. Current therapies have limited efficacy. Although the treatment of neonatal seizures has not changed significantly in the last several decades, there has been substantial progress in understanding developmental mechanisms that influence seizure generation and responsiveness to anticonvulsants. This article provides an overview of current approaches to the diagnosis and treatment of neonatal seizures, and some of the recent insights about the pathophysiology of neonatal seizures that may provide the foundation for better treatment are identified.

Sequential changes of hemodynamics and blood gases in newborn piglets with developing pneumothorax

INTRODUCTION

Little information is available regarding the temporal changes in hemodynamics and blood gases during the development of a moderate pneumothorax in a neonate. In this study, we aim to investigate the temporal changes of hemodynamics and arterial blood gases in a neonatal swine model of unilateral pneumothorax.

STUDY DESIGN

Prospective observational controlled animal research.

METHODS

Experimental pneumothorax (n = 9) was created by intermittent progressive introduction of 10 ml/kg of room-air every 5 min to a total 40 ml/kg, via a 20G Insyte(R) angiocatheter placed in the fourth intercostal space in line with the right frontal limb. Changes in heart rate, mean arterial pressure, central venous pressure (CVP), common carotid arterial flow (CCAF) and arterial blood gases were measured and compared with the normoxic baseline and a control group (n = 7) (ANOVA).

RESULTS

As the pneumothorax developed, SaO2 and PaO2 deteriorated after injecting 20 ml/kg of room-air (P < 0.001 vs. baseline and control), whereas the pH and PaCO(2) remained unchanged. CVP increased after injecting 30 ml/kg of room-air (P < 0.001), with no significant changes in heart rate and mean arterial pressure. Meanwhile, CCAF increased and carotid oxygen delivery declined after 30 ml/kg (P < 0.05).

CONCLUSIONS

Deterioration in oxygenation was noted early in the development of pneumothorax in newborn piglets followed by metabolic acidosis. CVP progressively increased despite the lack of significant changes in systemic hemodynamics when moderate pneumothorax developed. Although CCAF increased during a moderate pneumothorax, carotid oxygen delivery decreased.

Preterm infants with video-EEG confirmed seizures: outcome at 30 months of age

OBJECTIVE

Our aim was to identify early predictors of poor neurodevelopmental outcome and of subsequent epilepsy in very early preterm and late preterm newborns with neonatal seizures.

STUDY DESIGN

Fifty-one preterm infants with gestational age (GA) <or=36 weeks were identified among those admitted to the NICU of University Hospital of Parma between January 1999 and December 2003 and prospectively followed-up. They were subdivided in two Groups: early preterm newborns with a GA <or=29 weeks and those with GA between 30 and 36 weeks. Selection criteria included multiple digital-video-EEG confirmed neonatal seizures and a follow-up of at least 30 months. Independent variables considered for analysis included neonatal risk factors, etiology and type of seizures, EEG activity, and cerebral ultrasound scan examinations.

RESULTS

Ten infants had a favorable outcome, 17 died, and 23 had an adverse outcome. One infant was lost on follow-up. Apgar score at 1 min (O.R.=15.457, 95% CI: 2.236-106.850, p=0.006) and severely abnormal background EEG activity (O.R.=8.298, 95% CI: 1.316-52.301, p=0.024) were independent predictors of abnormal outcome. Nine infants presented post-neonatal epilepsy. Severely abnormal Cerebral Ultrasound scans were predictive of epilepsy (O.R.=13.72, 95% CI: 1.959-96.149, p=0.008).

CONCLUSIONS

Neonatal seizures in preterm infants are associated to a high rate of mortality and severe morbidity in survivors but no definitive differences between the two groups of preterm infants were found. Risk-factors for development of subsequent epilepsy are strongly related to the underlying brain damage.

Neonatal seizures

In childhood, the risk for seizures is greatest in the neonatal period. Currently used therapies have limited efficacy. Although the treatment of neonatal seizures has not significantly changed in the past several decades, there has been substantial progress in understanding developmental mechanisms that influence seizure generation and responsiveness to anticonvulsants. This review includes an overview of current approaches to the diagnosis and treatment of neonatal seizures, identifies some of the critical factors that have limited progress, and highlights recent insights about the pathophysiology of neonatal seizures that may provide the foundation for better treatment.

Treatments with midazolam and lidocaine for status epilepticus in neonates

Status epilepticus (SE) occurs in children of all ages. Recent epidemiologic investigations of SE show heightened morbidity and mortality in newborns and young infants. However, the existing definition of SE in newborns is not precise and not easily applied in clinical investigations or in clinical practice. To evaluate the underlying conditions, clinical features and treatment of SE in neonates in Japan, a retrospective multi-center study was performed. In the initial investigation, questionnaires were sent to pediatric neurologists in 194 neonatal intensive care units of university hospitals, children's hospitals, and general hospitals throughout in Japan. The questionnaires sought information on the background of each case, types of seizures, etiology of SE, treatments, results and adverse effects of treatment for patients less than 1 week old who had prolonged or frequently repeated seizures lasting more than 15 min and who are refractory to treatment with conventional anticonvulsants, such as diazepam (DZP), phenobarbital (PB) or phenytoin (PHT). As a secondary investigation, 65 cases from nine institutes, which completely fulfilled these criteria and were treated with midazolam (MDL) or lidocaine (Lid) to stop seizures were examined more fully. Subtle seizure and generalized tonic-clonic seizure were the most frequent seizure types. Neonatal SE was most frequently associated with hypoxic-ischemic encephalopathy, followed by intraventricular hemorrhage, central nervous system infections, and cerebral infarction. The final treatment outcome was available for 72.7% and 81.3% of MDL- and Lid-treated patients, respectively. Adverse effects of MDL and Lid were identified in 7.3% and 6.3% of patients, respectively. To reveal electroclinical seizures, clinical seizures without ictal discharge or other non-epileptic movements in neonates was important for appropriate treatment. MDL and Lid were useful drugs for the treatment of neonatal SE.

Risk factors for seizures in very low birthweight infants with periventricular leukomalacia

This population-based observational study aimed to determine the perinatal factors that were associated with the occurrence of seizures in very low birthweight infants with periventricular leukomalacia. The study sample consisted of 545 infants from the Israel National Very Low Birthweight Infant Database, gestational age 24 to 36 weeks, who survived beyond 28 days of age, in whom a late cranial ultrasonographic examination was performed and in whom periventricular leukomalacia was diagnosed. To evaluate the association between periventricular leukomalacia and confounding variables on the occurrence of seizures, the chi-square test, univariate analysis, and a logistic regression model were used. Of the 545 infants who developed periventricular leukomalacia, 102 (18.7%) had seizures. Significant independent predictors of seizures among these infants were decreasing gestational age, intraventricular hemorrhage, posthemorrhagic hydrocephalus, sepsis, and necrotizing enterocolitis. Infants with both sepsis and necrotizing enterocolitis had a 4.6-fold increased risk of seizures, further suggesting a possible role of infection in the pathogenesis of brain injury in preterm infants.