Prognostic factors and development of a scoring system for outcome of neonatal seizures in term infants

Early life seizures and olfactory communication in rats

OBJECTIVE

Early life seizures (ELS) are commonly associated with autism spectrum disorder (ASD); however, the exact role of ELS in the pathology is unknown. Prior studies have demonstrated social deficits, a core feature of ASD, following ELS; consequently, alterations in sensory modalities may contribute to the overall social deficits. Considering the speculated contribution of sensory deficit to social communication, we examined the developmental consequences of early postnatal kainic acid (KA)-induced seizures on olfactory preference and neural markers in the olfactory bulb in both male and female Sprague Dawley rats.

METHODS

KA-induced seizures or saline was administered. Rats were then exposed to a series of biologically relevant scents including male scent, female scent, nest scent, and phenylethylamine during the juvenile period and again during adulthood. Alterations in sensory modalities were expected to be expressed via abnormal preference for certain scents and/or production of abnormal ultrasonic vocalizations in response to scents. The olfactory bulbs were also assessed for the biologically relevant markers glial fibrillary acidic protein (GFAP) and calcium/calmodulin-dependent protein kinase II (CAMKII).

RESULTS

Our findings resulted in no significant differences in olfactory preference following ELS for juveniles or adults compared to controls. Similarly, there were no differences in GFAP expression or the ratio of phosphorylated CAMKII to CAMKII in either olfactory bulb. Interestingly, despite a lack of treatment differences, different scents were shown to elicit different responses in juvenile rats, yet these differences subsided in adulthood.

SIGNIFICANCE

Overall, the results of this study suggest that olfaction does not contribute to socialization deficit following ELS within the KA model.

Effect of neonatal seizure burden and etiology on the long-term outcome: data from a randomized, controlled trial

Background

Neonatal seizures are common, but the impact of neonatal seizures on long-term neurologic outcome remains unclear. We addressed this question by analyzing data from an early-phase controlled trial of bumetanide to treat neonatal seizures.

Methods

Neonatal seizure burden was calculated from continuous video-EEG data. Neurologic outcome was determined by standardized developmental tests and post-neonatal seizure recurrence.

Results

Of 111 enrolled neonates, 43 were randomized to treatment or control groups. There were no differences in neurologic outcome between treatment and control groups. A subgroup analysis was performed for 84 neonates with acute perinatal brain injury (57 HIE, 18 stroke, 9 ICH), most of whom (70%) had neonatal seizures. There was a significant negative correlation between seizure burden and developmental scores (p<0.01). Associations between seizure burden and developmental scores were stronger in HIE and stroke groups compared with ICH (p<0.05).

Conclusion

Bumetanide showed no long-term beneficial or adverse effects, as expected based on treatment duration versus duration of neonatal seizures. For neonates with perinatal brain injury, higher neonatal seizure burden correlated significantly with worse developmental outcome, particularly for ischemic versus hemorrhagic brain injury. These data highlight the need for further investigation of the long-term effects of both neonatal seizure severity and etiology.

Early-life seizures modify behavioral response to ultrasonic vocalization playback in adult rats

Early-life seizures (ELS) are associated with autism spectrum disorder (ASD); however, due to a lack of effective treatments for ELS, it is not clear whether ELS plays a causal role, potentiates the ASD phenotype, or is the result of a common pathophysiology. Deficits in communications are a core feature of ASD. To isolate the impact of ELS on communication, we probed the behavioral consequences of a single episode of kainic acid-induced early-life seizures (KA-ELS) in male and female Sprague-Dawley (CD) rats. Deficits in auditory communication were observed in adult male rats as assessed by behavioral response to ultrasonic vocalization (USV) playback. Ultrasonic vocalizations are classified into two major categories - 50-kHz (positive) calls and 22-kHz (aversive) calls. Behavioral response was assessed via rat preference for different USV playback in a radial arm maze. Response to 22-kHz calls was not impacted by ELS while response to 50-kHz calls was impacted. All rats demonstrated positional preference for the arms adjacent to where 50-kHz calls were playing compared to background noise; however, male ELS rats demonstrated a greater positional preference for the arms adjacent to where 50-kHz calls were playing compared to male control rats. These studies demonstrate that responses to socially relevant auditory cues are chronically altered in adult male rats following a single episode of ELS. We speculate that these changes contribute to previously reported social deficits associated with ELS.

Prevalence and predictors of adverse outcomes in neonatal seizures

OBJECTIVES

Neonatal seizures are significant cause of neonatal mortality and morbidity. Current study was planned to study prevalence of adverse outcomes in neonatal seizures and identify its predictors.

METHODS

This observational descriptive study was carried out on 220 neonates with seizures. Neonates who succumbed to illness/ death before investigations, or whose maternal records were incomplete were excluded. Blood sugar, serum calcium, serum electrolytes, and USG skull were done in all patients. CT scan, MRI and inborn errors of metabolism profile were done as and when indicated. Adverse outcomes were defined as death, phenobarbitone non responders, or abnormal examination at discharge. Antenatal, perinatal and neonatal predictors of adverse outcomes in neonatal seizures were evaluated.

RESULTS

Out of 220 neonates with seizures 76(34.5%) had adverse outcomes. Very low birth weight babies (≤1500 gm) [OR 1.27(CI 0.57-2.84)], microcephaly [OR 5.93 (CI 0.55-64.41)], Apgar score≤3 at 5 minutes [OR 11.28(CI 14.18-30.45)], seizure onset within 24 hours [OR 5.99(CI 12.43-14.78)], meningitis [OR 2.63(CI 0.08-6.39)], septicemia [OR1.22(CI 0.45-3.31)] and abnormal cranial USG [OR 7.95(CI 12.61-24.22)] were significant predictors of adverse outcomes in neonates with seizures.

CONCLUSION

Prematurity, very low birth weight, birth asphyxia, meningitis, septicemia and abnormal USG could predict adverse outcomes in neonatal seizures. Improved antenatal and neonatal clinical practices may help reduce adverse outcomes in these patients.

A Decision-Tree Approach to Assist in Forecasting the Outcomes of the Neonatal Brain Injury

Neonatal brain injury or neonatal encephalopathy (NE) is a significant morbidity and mortality factor in preterm and full-term newborns. NE has an incidence in the range of 2.5 to 3.5 per 1000 live births carrying a considerable burden for neurological outcomes such as epilepsy, cerebral palsy, cognitive impairments, and hydrocephaly. Many scoring systems based on different risk factor combinations in regression models have been proposed to predict abnormal outcomes. Birthweight, gestational age, Apgar scores, pH, ultrasound and MRI biomarkers, seizures onset, EEG pattern, and seizure duration were the most referred predictors in the literature. Our study proposes a decision-tree approach based on clinical risk factors for abnormal outcomes in newborns with the neurological syndrome to assist in neonatal encephalopathy prognosis as a complementary tool to the acknowledged scoring systems. We retrospectively studied 188 newborns with associated encephalopathy and seizures in the perinatal period. Etiology and abnormal outcomes were assessed through correlations with the risk factors. We computed mean, median, odds ratios values for birth weight, gestational age, 1-min Apgar Score, 5-min Apgar score, seizures onset, and seizures duration monitoring, applying standard statistical methods first. Subsequently, CART (classification and regression trees) and cluster analysis were employed, further adjusting the medians. Out of 188 cases, 84 were associated to abnormal outcomes. The hierarchy on etiology frequencies was dominated by cerebrovascular impairments, metabolic anomalies, and infections. Both preterms and full-terms at risk were bundled in specific categories defined as high-risk 75-100%, intermediate risk 52.9%, and low risk 0-25% after CART algorithm implementation. Cluster analysis illustrated the median values, profiling at a glance the preterm model in high-risk groups and a full-term model in the inter-mediate-risk category. Our study illustrates that, in addition to standard statistics methodologies, decision-tree approaches could provide a first-step tool for the prognosis of the abnormal outcome in newborns with encephalopathy.

Neonatal Seizures and Future Epilepsy: Predictive Value of Perinatal Risk Factors, Electroencephalography, and Imaging

Context

There are limited data in the literature about the relationship between neonatal seizures and subsequent epilepsy.

Aims

This study aimed to identify the predictive value of perinatal factors, etiologies, electroencephalography (EEG), and cranial ultrasonography (USG) for future epilepsy after neonatal seizures.

Materials and Methods

A total of 92 children with epilepsy who had seizures during their neonatal period were retrospectively evaluated whether the contribution of perinatal, natal, and postnatal risk factors confining clinical, laboratory, EEG, and imaging to subsequent epilepsy. Chi-square, uni, and multivariate logistic regression were applied to find out predictive factors for subsequent epilepsy.

Results

The rate of epilepsy was 57.6 % during 1-6 years follow-up. Birth weight, Apgar scores at first and fifth minutes, resuscitation history, abnormal neurological examination, etiology, response to the treatment, abnormal EEG, or USG findings were the most important risk factors for future epilepsy in univariate analysis (P < 0.05). Furthermore, asphyxia, fifth minute Apgar scores, response to the treatment, USG, and EEG were independent predictors (P < 0.05) for subsequent epilepsy in multivariate logistic regression. No relationship was found between subsequent epilepsy and mode of delivery, seizure onset time, and seizure types (P > 0.05).

Conclusion

Although there are recent promising and advanced techniques in neonatal intensive care units, asphyxia is still one of the most important risk factors for not only poor neurological conditions but also for future epilepsy after neonatal seizures. Apgar scores, treatment with multiple antiepileptic drugs, poor background EEG activity, and abnormal neuroimaging seem to have strong predictive values for developing subsequent epilepsy. Therefore, patients with a history of neonatal seizures should be closely followed up to decrease the risk of long-term outcomes and early detection of epilepsy.

Acute symptomatic neonatal seizures, brain injury, and long-term outcome: The role of neuroprotective strategies

INTRODUCTION

Neonatal seizures are frequent but underdiagnosed manifestations of acute brain dysfunction and an important contributor to unfavorable outcomes. Etiology and severity of brain injury are the single strongest outcome determinants.

AREAS COVERED

The authors will discuss the prognostic role of acute symptomatic seizures versus brain injury and the main neuroprotective and neurorestorative strategies for full-term and preterm infants.

EXPERT OPINION

Prolonged acute symptomatic seizures likely contribute to long-term outcomes by independently adding further brain injury to initial insults. Correct timing and dosing of therapeutic interventions, depending on etiology and gestational ages, need careful evaluation. Although promising strategies are under study, the only standard of care is whole-body therapeutic hypothermia in full-term newborns with hypoxic-ischemic encephalopathy.

Risk for infantile spasms after acute symptomatic neonatal seizures

OBJECTIVE

Infantile spasms (IS) is a severe epilepsy in early childhood. Early treatment of IS provides the best chance of seizure remission and favorable developmental outcome. We aimed to develop a prediction rule to accurately predict which neonates with acute symptomatic seizures will develop IS.

METHODS

We used data from the Neonatal Seizure Registry, a prospective, multicenter cohort of infants with acute symptomatic neonatal seizures born from July 2015 to March 2018. Neonates with acute symptomatic seizures who received clinical electroencephalography (EEG) and magnetic resonance imaging (MRI) and were younger than 2 years of age at the time of enrollment were included. We evaluated the association of neonatal EEG, MRI, and clinical factors with subsequent IS using bivariate analysis and best subsets logistic regression. We selected a final model through a consensus process that balanced statistical significance with clinical relevance.

RESULTS

IS developed in 12 of 204 infants (6%). Multiple potential predictors were associated with IS, including Apgar scores, EEG features, seizure characteristics, MRI abnormalities, and clinical status at hospital discharge. The final model included three risk factors: (a) severely abnormal EEG or ≥3 days with seizures recorded on EEG, (b) deep gray or brainstem injury on MRI, and (c) abnormal tone on discharge exam. The stratified risk of IS was the following: no factors 0% (0/82, 95% confidence interval [CI] 0%-4%), one or two factors 4% (4/108, 95% CI 1%-9%), and all three factors 57% (8/14, 95% CI 29%-83%).

SIGNIFICANCE

IS risk after acute symptomatic neonatal seizures can be stratified using commonly available clinical data. No child without risk factors, vs >50% of those with all three factors, developed IS. This risk prediction rule may be valuable for clinical counseling as well as for selecting participants for clinical trials to prevent post-neonatal epilepsy. This tailored approach may lead to earlier diagnosis and treatment and improve outcomes for a devastating early life epilepsy.

Evaluation of the prognostic factors in school age children who experienced neonatal seizures

BACKGROUND

This prospective study aimed to evaluate long-term neurodevelopmental outcomes and risk factors of the previously reported cohort, at their school age.

METHOD

We included neonates whose seizures were directly observed by the child neurologist or neonatologist based on clinical observations. They were assessed for cognitive and neurological outcomes at the age of 9-11 years. The test battery included a neurological examination, the Wechsler Intelligence Scale for Children-Revised (WISC-R) test, and patients with the diagnosis of cerebral palsy (CP) were graded according to the Gross Motor Function Classification System (GMFCS). The primary outcome of this study was to determine risk factors for the long-term prognosis of neonatal seizures.

RESULTS

For the long-term follow-up, 97 out of 112 patients of the initial cohort were available (86.6%). We found that 40 patients (41%) have the normal prognosis, 22 patients (22.7%) have the diagnosis of CP, and 30 patients (30.9%) were diagnosed as having epilepsy. Twelve out of 22 patients with CP had the diagnosis of epilepsy. The WISC-R full-scale IQ scores were <55 points in 27 patients (27.8%) and were >85 points in 40 patients (41.2%). According to GMFCS, 10 patients were classified as levels 1-2, and 12 patients were classified as levels 3-5. In multivariate regression analyses, 5-min APGAR score <6 was found to be an independent risk factor for CP, and 5-min APGAR score <6 and neonatal status epilepticus were independent risk factors for epilepsy.

CONCLUSIONS

This prospective cohort study reveals that abnormal school age outcome after neonatal seizures are significantly related to 5-min APGAR score <6 and neonatal status epilepticus.

Acute Symptomatic Seizures in Neonates

Seizures are an important sign of neurologic dysfunction in neonates, and they most often represent acute brain injury such as hypoxic-ischemic encephalopathy, stroke, or intracranial hemorrhage (acute symptomatic seizures). Clinical identification of seizures is not reliable since seizures in neonates often do not have an apparent clinical correlate; therefore, electroencephalography should be used to accurately diagnose and manage neonatal seizures. Seizures are refractory to initial loading doses of standard medications in >50% of cases. Since seizures are commonly associated with adverse acute and long-term outcomes, and the seizures themselves may result in additional brain injury, it is important to quickly recognize, diagnose, and treat seizures in neonates. Local practice pathways may optimize efficiency in assessment and treatment for affected newborns. Herein, we review the etiology, methods of diagnosis, treatment, and current knowledge gaps for neonatal seizures.

Outcomes After Acute Symptomatic Seizures in Children Admitted to a Neonatal Neurocritical Care Service

BACKGROUND

Neonatal seizures due to acute brain injury are associated with high rates of death, disability, and epilepsy. Our objective was to examine incidence of and risk factors for epilepsy among survivors of acute symptomatic neonatal seizures who were cared for by a neonatal neurocritical care service.

METHODS

Neonates with acute symptomatic seizures who were admitted to UCSF Benioff Children's Hospital Neuro-Intensive Care Nursery from July 2008 to June 2014 were considered for inclusion.

RESULTS

A total of 144 children with acute symptomatic seizures met study criteria and 37 (26%) died before age one. Eighty-seven children (85% of eligible survivors) were followed up to one year or longer. Epilepsy was diagnosed in eight children at median age 4.9 (interquartile range 1.7, 6.1) years. The cumulative incidence risk of epilepsy at one year was 2% (95% confidence interval 0.6% to 9%) and at five years was 7% (95% confidence interval 3% to 20%). Cerebral palsy was diagnosed in 21%. Bayley-III cognitive subscale less than 85 was present in 13%. Children with epilepsy were more likely to be preterm, have brain injury, and be discharged home on antiseizure medication, although the results were not significant after adjusted analysis.

CONCLUSIONS

The risk of epilepsy was lower and age at onset was older than in previous reports, which may be related to multiple factors including a neurocritical care approach, treatment of hypoxic-ischemic encephalopathy with hypothermia, high rate of neonatal transition to palliative care, and the exclusion of neonatal onset epilepsies. Continuation of antiseizure medications in infancy did not decrease the risk of epilepsy. Long-term, multicenter studies are needed to understand whether neonatal seizure management can alter the risk of epilepsy.

Outcomes after acute symptomatic seizures in neonates

Acute symptomatic seizures are a common sign of neurological dysfunction and brain injury in neonates and occur in approximately one to three per 1000 live births. Seizures in neonates are usually a sign of underlying brain injury and, as such, are commonly associated with adverse outcomes. Neurological morbidities in survivors often co-occur; epilepsy, cerebral palsy, and intellectual disability often occur together in the most severely affected children. Risk factors for adverse outcome include prematurity, low Apgar scores, low pH on the first day of life, seizure onset <24 or >72 h after birth, abnormal neonatal neurological examination, abnormal neonatal electroencephalographic background, status epilepticus, and presence and pattern of brain injury (particularly deep gray or brainstem injury). Despite this list of potential indicators, accurate prediction of outcome in a given child remains challenging. There is great need for long-term, multicenter studies to examine risk factors for, and pathogenesis of, adverse outcomes following acute symptomatic seizures in neonates.

Clinical Manifestations and Amplitude-integrated Encephalogram in Neonates with Early-onset Epileptic Encephalopathy

Background:

The patients with early-onset epileptic encephalopathy (EOEE) suffer from neurodevelopmental delay. The aim of this study was to analyze the clinical manifestations and amplitude-integrated encephalogram (aEEG) characteristics of infants with EOEE with onset within the neonatal period, to make early diagnosis to improve the prognosis.

Methods:

One-hundred and twenty-eight patients with neonatal seizure were enrolled and followed up till 1 year old. Sixty-six neonates evolved into EOEE were as the EOEE group, the other 62 were as the non-EOEE (nEOEE) group. Then we compared the clinical and aEEG characteristics between the two groups to analyze the manifestations in neonates with EOEE.

Results:

Compared to the nEOEE group, the incidence of daily seizure attacks, more than two types of convulsions, more than two antiepileptic drugs (AEDs) application, severely abnormal aEEG background, absence of cyclicity, and more than two seizures detection were significantly higher in the EOEE group (P < 0.05) (97% vs. 54.8%; 30.3% vs. 14.5%; 97.0% vs. 25.4%; 39.4% vs. 3.2%; 57.6% vs. 9.7%; and 56% vs. 3.2%, respectively). Severely abnormal background pattern (odds ratio [OR] = 0.081, 95% confidence interval [CI]: 0.009–0.729, P = 0.025) and more than two seizures detection by aEEG (OR = 0.158, 95% CI: 0.043–0.576, P = 0.005) were the independent risk factors for the evolvement into EOEE. The upper and lower margins of active sleep (AS) and quiet sleep (QS) were significantly higher in EOEE group than those of the control group (P < 0.05) (34.3 ± 13.6 vs. 21.3 ± 6.4; 9.9 ± 3.7 vs. 6.7 ± 2.2; 41.2 ± 15.1 vs. 30.4 ± 11.4; and 11.9 ± 4.4 vs. 9.4 ± 4.0; unit: μV, respectively). AS upper margin was demonstrated a higher diagnostic specificity and sensitivity for EOEE than another three parameters according to the receiver operating characteristic curves; the area under the curve was 0.827.

Conclusions:

The clinical characteristics of the neonatal seizure which will evolve into EOEE were more than two AEDs application, high seizure frequency (daily attack), and more than two types of the seizure. Significant high voltage, severely abnormal background, absence of cyclicity, and more than two seizures detected on aEEG were the meaningful indicators to the prediction of EOEE.

Prognostic factors of neurological outcomes in late-preterm and term infants with perinatal asphyxia

PURPOSE

This study aimed to identify prognostic factors of neurological outcomes, including developmental delay, cerebral palsy and epilepsy in late-preterm and term infants with perinatal asphyxia.

METHODS

All late-preterm and term infants with perinatal asphyxia or hypoxic-ischemic insults who admitted the neonatal intensive care unit of Inje University Sanggye Paik Hospital between 2006 and 2014 and were followed up for at least 2 years were included in this retrospective study. Abnormal neurological outcomes were defined as cerebral palsy, developmental delay and epilepsy.

RESULTS

Of the 114 infants with perinatal asphyxia, 31 were lost to follow-up. Of the remaining 83 infants, 10 died, 56 had normal outcomes, and 17 had abnormal outcomes: 14 epilepsy (82.4%), 13 cerebral palsy (76.5%), 16 developmental delay (94.1%). Abnormal outcomes were significantly more frequent in infants with later onset seizure, clinical seizure, poor electroencephalography (EEG) background activity, lower Apgar score at 1 and 5 minutes and abnormal brain imaging (P<0.05). Infants with and without epilepsy showed significant differences in EEG background activity, clinical and electrographic seizures on EEG, Apgar score at 5 minutes and brain imaging findings.

CONCLUSION

We should apply with long-term video EEG or amplitude integrated EEG in order to detect and management subtle clinical or electrographic seizures in neonates with perinatal asphyxia. Also, long-term, prospective studies with large number of patients are needed to evaluate more exact prognostic factors in neonates with perinatal asphyxia.

A systematic review of clinical decision rules for epilepsy

Clinical decision rules (CDRs) have been empirically demonstrated to improve patient satisfaction and enhance cost-effective care. The use of CDRs has not yet been robustly explored for epilepsy. We performed a systematic review of MEDLINE (from 1946) and Embase (from 1947) using Medical Subject Headings and keywords related to CDRs and epilepsy. We included original research of any language deriving, validating, or implementing a CDR using standardized definitions. Study quality was determined using a modified version of previously published criteria. A bivariate model was used to meta-analyze studies undergoing sequential derivation and validation studies. Of 2445 unique articles, 5 were determined to be relevant to this review. Three were derivation studies (three diagnostic and one therapeutic), one validation study, and one combined derivation and validation study. No implementation studies were identified. Study quality varied but was primarily of a moderate level. Two CDRs were validated and, thus, able to be meta-analyzed. Although initial measures of accuracy were high (sensitivity ~80% or above), they tended to diminish significantly in the validation studies. The pooled estimates of sensitivity and specificity both exhibited wide 95% confidence and prediction intervals that may limit their utility in routine practice. Despite the advances in therapeutic and diagnostic interventions for epilepsy, few CDRs have been developed to guide their use. Future CDRs should address common clinical scenarios such as efficient use of diagnostic tools and optimal clinical treatment decisions. Given their potential for advancing efficient, evidence-based, patient-centered healthcare, CDR development should be a priority in epilepsy.

Does diffusion restriction changes in magnetic resonance imaging predict neurological outcome in neonatal seizures?

BACKGROUND

Neonatal seizures are a common manifestation of brain dysfunction. Neonatal magnetic resonance imaging (MRI) has rapidly become the study of choice for the evaluation of central nervous systems disorders in newborns. According to a study conducted in Wilhelmina Children's Hospital, University Medical Center Utrecht, diffusion Restriction (DR) changes in the MRI is a good indicator of cell dysfunction (reversible or irreversible) within one week of insult.

OBJECTIVES

The main aim of this study was to find the association of DR changes in MRI of brain for neonatal seizures with long term neurodevelopment outcome.

METHODS

This is a retrospective observational study conducted in Sri Ramachandra University. Retrospective data was collected for the time period of January 2010 to December 2011 from medical records department (MRD) for patient data, neonatal intensive care unit and reports from PACS for MRI images and the Karthikeyan child development unit for their developmental follow up reports.

RESULTS

Comparison of composite score for various domains with DR changes was done with a t-test and comparison of babies with developmental delay and DR changes with Chi-square test. MRI DR changes with developmental outcome in different domains namely cognition, language-receptive/expressive, fine and gross motor was studied. There is no statistical significance among those who have DR changes and with those who do not have DR changes.

CONCLUSION

Though diffusion restriction changes in MRI may not predict adverse long term neuro developmental outcome, they can be of use with regards to individual etiological profile as in stroke. Larger group study and long term follow up is required to substantiate these findings.

Neonatal seizures in preterm newborns: A predictive model for outcome

BACKGROUND

With a reported prevalence of 22.2%, seizures in preterm newborns represent an emergent challenge, because they are often related to adverse outcome. The electroclinical features of preterm infants with neonatal seizures were evaluated in order to predict outcome.

METHODS

From 154 newborns with video-EEG confirmed neonatal seizures admitted to Parma University Hospital between January 1999 and December 2012, we collected 76 preterm newborns with neonatal seizures. Outcome was assessed at least at one year. Student t-test for unpaired data was used to compare means of continuous variables. We applied the χ(2) test to compare nominal data between preterm newborns with favorable versus adverse outcome, and between those with seizures versus those with status epilepticus. Then we determined the independent risk factors for adverse outcome with multivariate logistic regression analysis.

RESULTS

Birth weight, Apgar at 1st minute, neurologic examination, EEG, US brain scans and the presence of neonatal status epilepticus were different between preterm newborns with favorable and adverse outcome (p ≤ .049). Furthermore, birth weight, seizure onset, neurologic examination and EEG were different between the group with or without status (p ≤ .031). None of the infants with status epilepticus had a favorable outcome compared to 22.3% of those with neonatal seizures (p = .004). We also identified a predictive model that correctly classified outcome in 85.5% of subjects, with a high sensitivity for adverse outcome (>91.5%).

CONCLUSION

The presence of neonatal seizures in preterm newborns is highly related to an adverse outcome that can be predicted since the first days of life.

Mild systemic inflammation and moderate hypoxia transiently alter neuronal excitability in mouse somatosensory cortex

During the perinatal period, the brain is highly vulnerable to hypoxia and inflammation, which often cause white matter injury and long-term neuronal dysfunction such as motor and cognitive deficits or epileptic seizures. We studied the effects of moderate hypoxia (HYPO), mild systemic inflammation (INFL), or the combination of both (HYPO+INFL) in mouse somatosensory cortex induced during the first postnatal week on network activity and compared it to activity in SHAM control animals. By performing in vitro electrophysiological recordings with multi-electrode arrays from slices prepared directly after injury (P8-10), one week after injury (P13-16), or in young adults (P28-30), we investigated how the neocortical network developed following these insults. No significant difference was observed between the four groups in an extracellular solution close to physiological conditions. In extracellular 8mM potassium solution, slices from the HYPO, INFL, and HYPO+INFL group were more excitable than SHAM at P8-10 and P13-16. In these two age groups, the number and frequency of spontaneous epileptiform events were significantly increased compared to SHAM. The frequency of epileptiform events was significantly reduced by the NMDA antagonist D-APV in HYPO, INFL, and HYPO+INFL, but not in SHAM, indicating a contribution of NMDA receptors to this pathophysiological activity. In addition, the AMPA/kainate receptor antagonist CNQX suppressed the remaining epileptiform activity. Electrical stimulation evoked prominent epileptiform activity in slices from HYPO, INFL and HYPO+INFL animals. Stimulation threshold to elicit epileptiform events was lower in these groups than in SHAM. Evoked events spread over larger areas and lasted longer in treated animals than in SHAM. In addition, the evoked epileptiform activity was reduced in the older (P28-30) group indicating that cortical dysfunction induced by hypoxia and inflammation was transient and compensated during early development.

Autism and Epilepsy: Exploring the Relationship Using Experimental Models

The common co-occurrence of autism and epilepsy suggests that certain neurobiological mechanisms are shared between these disorders. In particular, the profusion of novel genetic mutations being discovered in autism and epilepsy points to abnormalities in synapse formation and function that alter the balance between neuronal excitation and inhibition. Animal models can be informative in sorting out the medical and behavioral complexities in autism and epilepsy and the relationship between them. As mechanistic information accrues, it is anticipated that mutation- and pathway-specific targeted treatments can be developed.

Gestational age-specific neonatal morbidity among pregnancies complicated by advanced maternal age: a population-based retrospective cohort study

OBJECTIVE

Compare significant neonatal morbidity frequency differences in advanced maternal age (AMA) versus non-AMA pregnancies, assessing which gestational week is associated with the lowest morbidity risk.

METHODS

Population-based retrospective cohort study. Adverse neonatal outcome frequency differences were stratified by each week of gestation. Multivariate logistic regression estimated the relative risk (RR) of composite neonatal morbidity for women aged 35-39, 40-44, 45-49 and 50-55 versus 18-34 years, adjusted sequentially for relevant risk factors.

RESULTS

Neonatal morbidity decreased with each advancing week of term gestation, lowest at 39 weeks for all the groups. Adverse neonatal outcome risk for births to AMA women increased at 40 weeks: 35-39 years adjRR 1.12 [1.01-1.24] and ≥40 years 1.24 [1.01-1.52]. Each older maternal age category had increased risk for overall neonatal morbidity: 35-39 years adjRR 1.11 [95% CI 1.08-1.15], 40-44 years 1.21 [95% CI 1.14-1.29] and 45-49 years 1.34 [95% CI 1.05-1.69].

CONCLUSIONS

Lowest neonatal morbidity risk is at 39-week gestation with a significantly increased risk observed thereafter, especially in women ≥40 years.

Neonatal Seizures: Impact on Neurodevelopmental Outcomes

Neonatal period is the most vulnerable time for the occurrence of seizures, and neonatal seizures often pose a clinical challenge both for their acute management and frequency of associated long-term co-morbidities. Etiologies of neonatal seizures are known to play a primary role in the anti-epileptic drug responsiveness and the long-term sequelae. Recent studies have suggested that burden of acute recurrent seizures in neonates may also impact chronic outcomes independent of the etiology. However, not many studies, either clinical or pre-clinical, have addressed the long-term outcomes of neonatal seizures in an etiology-specific manner. In this review, we briefly review the available clinical and pre-clinical research for long-term outcomes following neonatal seizures. As the most frequent cause of acquired neonatal seizures, we focus on the studies evaluating long-term effects of HIE-seizures with the goal to evaluate (1) what parameters evaluated during acute stages of neonatal seizures can reliably be used to predict long-term outcomes? and (2) what available clinical and pre-clinical data are available help determine importance of etiology vs. seizure burdens in long-term sequelae.

Neonatal seizures: Predictors of adverse outcome

Context:

Early detection of predictors of adverse outcome will be helpful for neonatologists to plan management, follow up and rehabilitation in advance so that neurological disability can be minimised.

Aims:

The purpose of this study was to determine the factors affecting the adverse outcome of neonatal seizures.

Settings and Design:

This is a prospective study conducted in the neonatal unit of a tertiary care hospital. One hundred and eight newborns consecutively admitted with seizures were included in this study.

Materials and Methods:

Data was collected regarding perinatal history and seizure and evaluated for etiology. We conducted a retrospective analysis to identify the factors associated with adverse outcome after neonatal seizures.

Statistical Analysis Used:

Chi-square test with degree of freedom = 1 was used to find the variables significantly associated with adverse outcome (P < 0.05).

Results:

Gestational age, birth weight, Apgar score at 5 min, seizure onset <24 hrs, status epilepticus, radiological findings and EEG findings were significantly associated with outcome.

Conclusion:

Mortality and severe neurological impairment after neonatal seizure is associated with prematurity, LBW, low Apgar score at 5 min, etiologies like meningitis, sepsis, severe HIE, brain malformations, grade 3 or 4 IVH or intracranial haemorrhage, seizure onset <24 hours, presence of status epilepticus, severely abnormal radiological and EEG findings.

Neonatal seizures: magnetic resonance imaging adds value in the diagnosis and prediction of neurodisability

AIM

To determine the aetiological associations, neurological sequelae and role of magnetic resonance imaging (MRI) in term newborn infants with seizures.

METHODS

Cohort study of infants ≥37 weeks' gestation delivered in a tertiary level centre, prospectively identified and followed longitudinally for 18-24 months.

RESULTS

An underlying aetiology was found in 95% of the 77 infants identified with seizures (3.0/1000 live births). The most common diagnosis was hypoxic-ischaemic encephalopathy (HIE) (65%), followed by neonatal stroke (12%). Nine infants died, 28 of the 68 survivors developed neurodevelopmental impairment (NDI), and 15 had recurrent seizures in the first 2 years, with both outcomes more likely in those with a diagnosis other than HIE. Abnormal MRI findings were found in 45 of the 70 infants imaged. The absence of major cerebral lesions was highly predictive of a normal neurological outcome.

CONCLUSION

We report the first cohort of term infants with seizures fully investigated by MRI. The universal use of MRI enabled a cause to be identified in 95% of cases. The probability of having NDI or recurrence of seizures was extremely low with absence of major cerebral lesions on MRI. This study demonstrates the added value of MRI for diagnosis of aetiology and the prediction of neurological outcome.

Impact of transient acute hypoxia on the developing mouse EEG

Hypoxemic events are common in sick preterm and term infants and represent the most common cause of seizures in the newborn period. Neonatal seizures often lack clinical correlates and are only recognized by electroencephalogram (EEG). The mechanisms leading from a hypoxic/ischemic insult to acute seizures in neonates remain poorly understood. Further, the effects of hypoxia on EEG at various developmental stages have not been fully characterized in neonatal animals, in part due to technical challenges. We evaluated the impact of hypoxia on neonatal mouse EEG to define periods of increased susceptibility to seizures during postnatal development. Hippocampal and cortical electrodes were implanted stereotaxically in C57BL/6 mice from postnatal age 3 (P3) to P15. Following recovery, EEG recordings were obtained during baseline, acute hypoxia (4% FiO2 for 4min) and reoxygenation. In baseline recordings, maturation of EEG was characterized by the appearance of a more continuous background pattern that replaced alternating high and low amplitude activity. Clinical seizures during hypoxia were observed more frequently in younger animals (100% P3-4, 87.5% P5-6, 93% P7-8, 83% P9-10, 33% P11-12, 17% P15, r(2)=0.81) and also occurred at higher FiO2 in younger animals (11.2±1.1% P3-P6 vs. 8.9±0.8% P7-12, p<0.05). Background attenuation followed the initial hypoxemic seizure; progressive return to baseline during reoxygenation was observed in survivors. Electrographic seizures without clinical manifestations were observed during reoxygenation, again more commonly in younger animals (83% P3-4, 86% P5-6, 75% P7-8, 71% P9-10, 20% P11-12, r(2)=0.82). All P15 animals died with this duration and degree of hypoxia. Post-ictal abnormalities included burst attenuation and post-anoxic myoclonus and were more commonly seen in older animals. In summary, neonatal mice exposed to brief and severe hypoxia followed by rapid reoxygenation reliably develop seizures and the response to hypoxia varies with postnatal age and maturation.

Risk factors and scoring system as a prognostic tool for epilepsy after neonatal seizures

BACKGROUND

Neonatal seizures may cause irreversible changes to the immature brain and. A scoring system for early prognostic information could be a useful clinical tool. The aim of the study was to analyze risk factors for epilepsy after neonatal seizures, to validate Garfinkle's scoring system, and to analyze whether a new scoring system is feasible.

METHODS

A retrospective study of 176 newborns (59.1% boys, 40.9% girls, 70.5% term, 29.5% preterm; mean birth weight 2820 g), admitted to the Department of Neonatology, Division of Pediatrics, University Medical Centre, Ljubljana, because of neonatal seizures (clinical and/or neurophysiological), was performed. Epilepsy rate between 2 and 12 years of follow-up was 18.1%. Five independent predictors from Garfinkle's study and other known predictors were entered into hierarchical binary logistic regression models and analyzed through four steps to identify independent predictors of epilepsy. We tested whether any of the predictors was an effect modifier.

RESULTS

Of five potential predictors from Garfinkle's score, electroencephalograph background findings and etiology were predictive. Etiologies, gestation, mode of delivery, duration of seizures, and other risk factors at birth were found to be independent predictors. Duration of seizures has a different effect on prognosis depending on the gestational age.

CONCLUSION

Gestational age determines the association between duration of seizures and epilepsy. Scoring systems to predict development of epilepsy after neonatal seizures need to limit interaction between important predictor variables.

The prognostic value of amplitude-integrated EEG in full-term neonates with seizures

Neonatal seizures pose a high risk for adverse outcome in survived infants. While the prognostic value of amplitude-integrated electroencephalogram (aEEG) is well established in neonates with encephalopathy and asphyxia, neonatal seizure studies focusing on the direct correlation between early aEEG measurement and subsequent neurologic outcome are scarce. In this study, the prognostic value of aEEG features was systematically analyzed in 143 full-term neonates to identify prognostic indicators of neurodevelopmental outcome. Neonatal aEEG features of background pattern, cyclicity, and seizure activity, as well as the etiology of neonatal seizures, were significantly associated with neurodevelopmental outcome at one year of age. aEEG background pattern was highly associated with neurologic outcomes (χ² = 116.9), followed by aEEG cyclicity (χ² = 87.2) and seizure etiology (χ² = 79.3). Multiple linear regression showed that the four predictors explained 71.2% of the variation in neurological outcome, with standardized β coefficients of 0.44, 0.24, 0.22, and 0.14 for the predictors of aEEG background pattern, cyclicity, etiology, and aEEG seizure activity, respectively. This clinically applicable scoring system based on etiology and three aEEG indices would allow pediatricians to assess the risk for neurodevelopmental impairment and facilitate an early intervention in newborns developing seizures.

Diagnosing neonatal seizures and status epilepticus

Continuous electroencephalographic (CEEG) monitoring is often applied in the Neonatal Intensive Care Unit to aid in the diagnosis and management of seizures. Neonatal seizures are particularly difficult to identify on the basis of clinical observation alone; diagnosis is greatly facilitated by CEEG monitoring. There is building evidence to suggest which neonates are at highest risk for seizures, and how CEEG can aid diagnosis. For the neurophysiologist, the unique features of neonatal seizures can distinguish them from nonictal patterns. These features include duration, location, morphology, and evolution. At the extreme, very frequent or prolonged neonatal seizures constitute status epilepticus. There is no consensus definition for neonatal status epilepticus, although the proposed criteria share some features. This article reviews available evidence to guide the application and interpretation of CEEG in the diagnosis of neonatal seizures and status epilepticus.

Prognostic factors of developmental outcome in neonatal seizures in term infants

BACKGROUND

The purpose of this study was to identify prognostic indicators of neurodevelopmental outcome in term infants who experienced clinical neonatal seizure.

METHODS

This is a retrospective, observational hospital-based study. Term infants who experienced clinical neonatal seizure between January 1999 and December 2009 were enrolled. Adverse outcomes were defined as death, cerebral palsy, global developmental delay, and/or epilepsy. The associations between adverse outcomes and 17 variables, including sex, mode of delivery, being small of gestational age, maternal illness, perinatal insults, meconium stained liquor, Apgar score at 1 and 5 minutes, seizure onset age, seizure type, etiology, electroencephalography (EEG) findings, antiepileptic drug efficacy, presence of metabolic acidosis, and cranial ultrasonographic findings, and presence of congenital heart disease were analyzed.

RESULTS

Among the 232 enrolled infants, 125 had a normal outcome and 14 had mild functional disability (59.9%), and 55 (23.7%) survived with one or more neurodevelopmental impairments (7 with cerebral palsy, 48 with global developmental delay), and 38 (16.4%) died. Forty-seven (23.0%) of the 204 patients who survived after the first discharge had epilepsy. Ten variables were associated with adverse outcome on univariate analysis, but only four variables, i.e., including abnormal cranial ultrasonography findings, abnormal anterior cerebral artery resistance index, abnormal EEG findings, and presence of congenital heart disease were independent predictors on multivariate logistic regression analysis.

CONCLUSION

In term infants with neonatal seizures, several risk factors related to adverse outcome were recognized. Physicians should pay more attention to these factors when handling patients with neonatal seizures.

Altered short-term plasticity in the prefrontal cortex after early life seizures

Seizures during development are a relatively common occurrence and are often associated with poor cognitive outcomes. Recent studies show that early life seizures alter the function of various brain structures and have long-term consequences on seizure susceptibility and behavioral regulation. While many neocortical functions could be disrupted by epileptic seizures, we have concentrated on studying the prefrontal cortex (PFC) as disturbance of PFC functions is involved in numerous co-morbid disorders associated with epilepsy. In the present work we report an alteration of short-term plasticity in the PFC in rats that have experienced early life seizures. The most robust alteration occurs in the layer II/III to layer V network of neurons. However short-term plasticity of layer V to layer V network was also affected, indicating that the PFC function is broadly influenced by early life seizures. These data strongly suggest that repetitive seizures early in development cause substantial alteration in PFC function, which may be an important component underlying cognitive deficits in individuals with a history of seizures during development.

Evaluation of etiologic and prognostic factors in neonatal convulsions

This study evaluated etiologic and risk factors affecting long-term prognoses of neurologic outcomes in newborns with neonatal seizures. We enrolled patients at chronologic ages of 23-44 months, referred to the Department of Pediatric Neurology, Istanbul Medical Faculty, from January 1, 2007-December 31, 2009, after manifesting seizures in their first postnatal 28 days. Of 112 newborns, 41 were female, 71 were male, 33 were preterm, and 79 were full-term. Perinatal asphyxia (28.6%) and intracranial hemorrhage (17%) were the most common causes of neonatal seizures. Cerebral palsy developed in 27.6% of patients during follow-up. The incidence of epilepsy was 35.7%. Almost 50% of patients manifested developmental delay in one or more areas. Global developmental delay was the most common (50.8%) neurologic disorder. The correlation between gestational age or birth weight and adverse outcomes was nonsignificant. Etiology, Apgar score, need for resuscitation at birth, background electroencephalogram, neonatal status epilepticus, cranial imaging findings, type/duration of antiepileptic treatment, and response to acute treatment were all strong prognostic factors in neurologic outcomes. Neonatal seizures pose a threat of neurologic sequelae for preterm and full-term infants. Although the number of recognized etiologic factors in neonatal seizures has increased because of improvements in neonatology and diagnostic methods, perinatal asphyxia remains the most common factor.

Approach to neonatal seizures

Neonatal seizures can be difficult to recognize given the variation in their presentation. Hence, diagnosis and appropriate treatment may be delayed. Morphology of seizures in this age group is discussed, followed by common etiological entities. Special emphasis is laid on treatable disease states such as vitamin responsive seizure disorders and benign conditions that may not warrant aggressive treatment. Conditions that may have devastating neurological consequences are discussed in some detail so that the treating pediatrician can provide realistic information to the parents of such newborns. Imaging and laboratory workup is outlined, followed by guidelines for ordering and interpreting an electroencephalogram in this age group. Finally, treatment options in the form of antiepileptics are discussed with mention of new avenues for diagnosis and treatment that may become commonly employed in the future.

Classification of clinical semiology in epileptic seizures in neonates

The clinical semiology of 61 neonatal seizures with EEG correlates, in 24 babies was analysed. Most seizures (89%) had multiple features during the EEG discharge. The seizures were classified using the prominent clinical feature at onset, and all features seen during the seizure, using an extended classification scheme. Orolingual features occurred most frequently at onset (30%), whereas ocular phenomena occurred most often during the seizure (70%). Orolingual, ocular and autonomic features were seen at onset in 55% of the seizures. Seizure onsets with clonic, tonic and hypomotor features were seen in 20%, 8% and 18% respectively. Clinico-electrical correlations were as follows. The EEG discharge involved both hemispheres in 54% of all seizures, in clonic seizures this was 93%. Focal clonic seizures were associated with EEG seizure onset from the contralateral hemisphere. Majority of the clonic and hypomotor seizures had a left hemisphere ictal EEG onset. Orolingual seizures frequently started from the right hemisphere, whereas ocular and autonomic seizures arose from either hemisphere. There was no significant difference in mortality, morbidity, abnormal neuroimaging and EEG background abnormalities in babies with or without clonic seizures. This study provides insights into neuronal networks that underpin electroclinical seizures, by analysing and classifying the obvious initial clinical features and those during the seizure.

Outcome of ventilated infants born at term without major congenital abnormalities

The longer-term outcome of term-born infants without congenital anomalies requiring ventilation in the first 24 h after birth has rarely been reported. Our aims were to determine the mortality and long-term morbidity of such infants and identify risk factors for adverse outcome. The outcomes of 43 of 45 infants born at term consecutively requiring mechanical ventilation were reviewed. The infants had: meconium aspiration syndrome (n = 11), hypoxic ischaemic encephalopathy (HIE) (n = 11), respiratory depression (n = 12), sepsis (n = 5), persistent pulmonary hypertension of the newborn (n = 3) and middle cerebral artery infarction (n = 1). Eleven infants developed seizures (26%), 13 (30%) had abnormal electroencephalograms and 11 (26%) had abnormal MRI scans; 26% had an adverse outcome: six died, and five had severe neurodisability at 2 years. The infants with congenital toxoplasmosis and a middle cerebral artery infarction were excluded from the prediction analysis. In the remaining 41 patients, requirement for anticonvulsants (relative risk, RR = 4.44, 95% CI = 1.48 to 12.70; p = 0.014) and prolonged ventilation (longer than 3 days) (RR 4.83, 95% CI 1.51 to 15.64) predicted adverse outcome. Infants with HIE had an increased risk of adverse outcome (relative risk 5.45, 95% CI 1.01 to 33.85), but an adverse outcome occurred in infants with other diagnoses.

CONCLUSION

Mortality and neurodisability at follow-up were common in infants born at term without major congenital anomalies who required mechanical ventilation in the first 24 h after birth, particularly in those who developed seizures requiring treatment and prolonged ventilation.