Term early-onset neonatal seizures: obstetric characteristics, etiologic classifications, and perinatal care

Amplitude integrated EEG: how much it helps in prognostication in neonatal encephalopathy?

INTRODUCTION

Neonatal encephalopathy (NE) is associated with a high risk of adverse neurological outcomes. Several neurodiagnostic tests have been evaluated to predict the prognosis. Amplitude integrated Electroencephalogram (aEEG) is now being commonly used for bedside evaluation of cerebral function. There is limited data on the role of aEEG for prognostication in NE, from resource-limited settings.

OBJECTIVE

To evaluate the predictive ability of aEEG for abnormal neurological outcomes in neonatal encephalopathy or neonates with encephalopathy.

METHODS

Neonates above 35 weeks of gestation admitted to NICU in a tertiary care hospital with a diagnosis of encephalopathy were enrolled. Clinical characteristics severity of encephalopathy and seizures were recorded. Amplitude integrated recording was started at admission and continued till recovery of trace to normal or for 10 days. The primary outcome was death or abnormal neurological status at 3-6 months of age. The study was registered in the Clinical Trial Registry of India (CTRI/2013/05/003612).

RESULTS

The incidence of NE was 6% of total admission. Moderate and severe encephalopathy occurred in 58 and 39% of babies respectively. Hypoxic-ischemic encephalopathy was the most common cause. Clinical seizures occurred in 91% of cases. An abnormal aEEG trace was observed in 51 (76.1%) infants with NE. For adverse neurological outcomes at an age average of 4.5 months of age, aEEG had a sensitivity, specificity, NPV, and PPV of 100, 54.2, 100, and 77.5, respectively.

CONCLUSIONS

Clinical staging and aEEG has good predictive ability to detect an adverse neurological outcome. aEEG improves the ability to predict abnormal outcome in babies with moderate encephalopathy. Early recovery of aEEG abnormality correlates with better neurodevelopmental outcomes.KEY MESSAGESWhat's known: aEEG is a useful modality to assess neurodevelopmental outcomes however data from developing countries is lacking.What's new: aEEG monitoring in babies in neonatal encephalopathy may improve the prediction of abnormal neurological outcomes in babies with moderate encephalopathy.

Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour

BACKGROUND

Cardiotocography (CTG) records changes in the fetal heart rate and their temporal relationship to uterine contractions. The aim is to identify babies who may be short of oxygen (hypoxic) to guide additional assessments of fetal wellbeing, or determine if the baby needs to be delivered by caesarean section or instrumental vaginal birth. This is an update of a review previously published in 2013, 2006 and 2001.

OBJECTIVES

To evaluate the effectiveness and safety of continuous cardiotocography when used as a method to monitor fetal wellbeing during labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (30 November 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials involving a comparison of continuous cardiotocography (with and without fetal blood sampling) with no fetal monitoring, intermittent auscultation intermittent cardiotocography.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, quality and extracted data from included studies. Data were checked for accuracy.

MAIN RESULTS

We included 13 trials involving over 37,000 women. No new studies were included in this update.One trial (4044 women) compared continuous CTG with intermittent CTG, all other trials compared continuous CTG with intermittent auscultation. No data were found comparing no fetal monitoring with continuous CTG. Overall, methodological quality was mixed. All included studies were at high risk of performance bias, unclear or high risk of detection bias, and unclear risk of reporting bias. Only two trials were assessed at high methodological quality.Compared with intermittent auscultation, continuous cardiotocography showed no significant improvement in overall perinatal death rate (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.59 to 1.23, N = 33,513, 11 trials, low quality evidence), but was associated with halving neonatal seizure rates (RR 0.50, 95% CI 0.31 to 0.80, N = 32,386, 9 trials, moderate quality evidence). There was no difference in cerebral palsy rates (RR 1.75, 95% CI 0.84 to 3.63, N = 13,252, 2 trials, low quality evidence). There was an increase in caesarean sections associated with continuous CTG (RR 1.63, 95% CI 1.29 to 2.07, N = 18,861, 11 trials, low quality evidence). Women were also more likely to have instrumental vaginal births (RR 1.15, 95% CI 1.01 to 1.33, N = 18,615, 10 trials, low quality evidence). There was no difference in the incidence of cord blood acidosis (RR 0.92, 95% CI 0.27 to 3.11, N = 2494, 2 trials, very low quality evidence) or use of any pharmacological analgesia (RR 0.98, 95% CI 0.88 to 1.09, N = 1677, 3 trials, low quality evidence).Compared with intermittent CTG, continuous CTG made no difference to caesarean section rates (RR 1.29, 95% CI 0.84 to 1.97, N = 4044, 1 trial) or instrumental births (RR 1.16, 95% CI 0.92 to 1.46, N = 4044, 1 trial). Less cord blood acidosis was observed in women who had intermittent CTG, however, this result could have been due to chance (RR 1.43, 95% CI 0.95 to 2.14, N = 4044, 1 trial).Data for low risk, high risk, preterm pregnancy and high-quality trials subgroups were consistent with overall results. Access to fetal blood sampling did not appear to influence differences in neonatal seizures or other outcomes.Evidence was assessed using GRADE. Most outcomes were graded as low quality evidence (rates of perinatal death, cerebral palsy, caesarean section, instrumental vaginal births, and any pharmacological analgesia), and downgraded for limitations in design, inconsistency and imprecision of results. The remaining outcomes were downgraded to moderate quality (neonatal seizures) and very low quality (cord blood acidosis) due to similar concerns over limitations in design, inconsistency and imprecision.

AUTHORS' CONCLUSIONS

CTG during labour is associated with reduced rates of neonatal seizures, but no clear differences in cerebral palsy, infant mortality or other standard measures of neonatal wellbeing. However, continuous CTG was associated with an increase in caesarean sections and instrumental vaginal births. The challenge is how best to convey these results to women to enable them to make an informed decision without compromising the normality of labour.The question remains as to whether future randomised trials should measure efficacy (the intrinsic value of continuous CTG in trying to prevent adverse neonatal outcomes under optimal clinical conditions) or effectiveness (the effect of this technique in routine clinical practice).Along with the need for further investigations into long-term effects of operative births for women and babies, much remains to be learned about the causation and possible links between antenatal or intrapartum events, neonatal seizures and long-term neurodevelopmental outcomes, whilst considering changes in clinical practice over the intervening years (one-to-one-support during labour, caesarean section rates). The large number of babies randomised to the trials in this review have now reached adulthood and could potentially provide a unique opportunity to clarify if a reduction in neonatal seizures is something inconsequential that should not greatly influence women's and clinicians' choices, or if seizure reduction leads to long-term benefits for babies. Defining meaningful neurological and behavioural outcomes that could be measured in large cohorts of young adults poses huge challenges. However, it is important to collect data from these women and babies while medical records still exist, where possible describe women's mobility and positions during labour and birth, and clarify if these might impact on outcomes. Research should also address the possible contribution of the supine position to adverse outcomes for babies, and assess whether the use of mobility and positions can further reduce the low incidence of neonatal seizures and improve psychological outcomes for women.

Endotracheal suction in term non vigorous meconium stained neonates-A pilot study

AIM

To evaluate the effect of 'No endotracheal suction' on occurrence of meconium aspiration syndrome (MAS) and/or all-cause mortality in non-vigorous neonates born through meconium stained amniotic fluid (MSAF).

METHODS

This pilot randomized controlled trial enrolled term non-vigorous neonates (≥37 weeks) born through MSAF. Neonates randomized to 'No Endotracheal suction group' ('No ET' Group; n=88) did not undergo endotracheal suction before the definitive steps of resuscitation. Neonates randomized to 'Endotracheal suction group' ('ET' Group; n=87) underwent tracheal suction as part of the initial steps as per the current NRP recommendations. The primary outcome was occurrence of MAS and/or death. Secondary outcome variables were duration and severity of respiratory distress, need for respiratory support, development of hypoxic ischemic encephalopathy (HIE) and duration of oxygen therapy and hospitalization.

RESULTS

Baseline characters including birth weight and gestational age were similar between the two groups. MAS was present in 23 (26.1%) vs. 28 (32.2%) neonates in 'No ET' and 'ET' groups respectively (OR 0.4 (0.12-1.4); p=0.14) with 4 (4.6%) and 9 (10.34%) deaths amongst these neonates with MAS in respective groups (OR 0.75 (0.62-1.2); p=0.38). Other parameters like severity and duration of respiratory distress, need for respiratory support, incidence of HIE, duration of oxygen therapy and duration of hospitalization were comparable.

CONCLUSION

This study demonstrates that it is feasible to randomize non-vigorous infants born through meconium stained liquor to receive on not receive endotracheal suction. There is a need for a multi-center trial to address whether the current practices and guidelines can be justified.

Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour

BACKGROUND

Cardiotocography (known also as electronic fetal monitoring), records changes in the fetal heart rate and their temporal relationship to uterine contractions. The aim is to identify babies who may be short of oxygen (hypoxic), so additional assessments of fetal well-being may be used, or the baby delivered by caesarean section or instrumental vaginal birth.

OBJECTIVES

To evaluate the effectiveness of continuous cardiotocography during labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (31 December 2012) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials involving a comparison of continuous cardiotocography (with and without fetal blood sampling) with (a) no fetal monitoring, (b) intermittent auscultation (c) intermittent cardiotocography.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, quality and extracted data from included studies.

MAIN RESULTS

Thirteen trials were included with over 37,000 women; only two were judged to be of high quality.Compared with intermittent auscultation, continuous cardiotocography showed no significant improvement in overall perinatal death rate (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.59 to 1.23, n = 33,513, 11 trials), but was associated with a halving of neonatal seizures (RR 0.50, 95% CI 0.31 to 0.80, n = 32,386, nine trials). There was no significant difference in cerebral palsy rates (RR 1.75, 95% CI 0.84 to 3.63, n = 13,252, two trials). There was a significant increase in caesarean sections associated with continuous cardiotocography (RR 1.63, 95% CI 1.29 to 2.07, n = 18,861, 11 trials). Women were also more likely to have an instrumental vaginal birth (RR 1.15, 95% CI 1.01 to 1.33, n = 18,615, 10 trials).Data for subgroups of low-risk, high-risk, preterm pregnancies and high-quality trials were consistent with overall results. Access to fetal blood sampling did not appear to influence the difference in neonatal seizures nor any other prespecified outcome.

AUTHORS' CONCLUSIONS

Continuous cardiotocography during labour is associated with a reduction in neonatal seizures, but no significant differences in cerebral palsy, infant mortality or other standard measures of neonatal well-being. However, continuous cardiotocography was associated with an increase in caesarean sections and instrumental vaginal births. The challenge is how best to convey these results to women to enable them to make an informed choice without compromising the normality of labour.

Neuroimaging of neonatal encephalopathies

Neonatal brain disorders consist of a wide chapter including brain malformations, hypoxic-ischemic encephalopathy (HIE), intracranial infections, perinatal trauma and metabolic encephalopathy. We will focus here on HIE, intracranial infections (especially materno-fetal infection with or without prolonged and/or premature rupture of membranes) and metabolic encephalopathy, those three conditions being the most frequent so far in our experience. Neonatal stroke is also analyzed. Moreover minor perinatal events might be superimposed on an already damaged (infective, edematous, metabolically abnormal or maldeveloped) brain, highlighting the main role and potential benefits of neuroimaging during the neonatal period. The different methods of brain imaging are thus reported with their advantages and disadvantages.

Fetal and Neonatal Thrombophilia

Thrombophilia of the fetus and neonate may contribute to higher prevalence of perinatal thrombosis. Due to the potential interaction between thrombophilic risk factors of the neonate and maternal thrombophilia and placental vasculopathy, we recommend thrombophilia assessment be performed in any child and in the mother in case of perinatal thrombosis. Further attention and larger prospective studies are required to establish the role of thrombophilic risk factors in the pathogenesis of any other perinatal complications.

Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour

BACKGROUND

Cardiotocography (sometimes known as electronic fetal monitoring), records changes in the fetal heart rate and their temporal relationship to uterine contractions. The aim is to identify babies who may be short of oxygen (hypoxic), so additional assessments of fetal well-being may be used, or the baby delivered by caesarean section or instrumental vaginal birth.

OBJECTIVES

To evaluate the effectiveness of continuous cardiotocography during labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (March 2006), CENTRAL (The Cochrane Library 2005, Issue 4), MEDLINE (1966 to December 2005), EMBASE (1974 to December 2005), Dissertation Abstracts (1980 to December 2005) and the National Research Register (December 2005).

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials involving a comparison of continuous cardiotocography (with and without fetal blood sampling) with (a) no fetal monitoring, (b) intermittent auscultation (c) intermittent cardiotocography.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed eligibility, quality and extracted data.

MAIN RESULTS

Twelve trials were included (over 37,000 women); only two were high quality. Compared to intermittent auscultation, continuous cardiotocography showed no significant difference in overall perinatal death rate (relative risk (RR) 0.85, 95% confidence interval (CI) 0.59 to 1.23, n = 33,513, 11 trials), but was associated with a halving of neonatal seizures (RR 0.50, 95% CI 0.31 to 0.80, n = 32,386, nine trials) although no significant difference was detected in cerebral palsy (RR 1.74, 95% CI 0.97 to 3.11, n = 13,252, two trials). There was a significant increase in caesarean sections associated with continuous cardiotocography (RR 1.66, 95% CI 1.30 to 2.13, n =18,761, 10 trials). Women were also more likely to have an instrumental vaginal birth (RR 1.16, 95% CI 1.01 to 1.32, n = 18,151, nine trials). Data for subgroups of low-risk, high-risk, preterm pregnancies and high quality trials were consistent with overall results. Access to fetal blood sampling did not appear to influence the difference in neonatal seizures nor any other prespecified outcome.

AUTHORS' CONCLUSIONS

Continuous cardiotocography during labour is associated with a reduction in neonatal seizures, but no significant differences in cerebral palsy, infant mortality or other standard measures of neonatal well-being. However, continuous cardiotocography was associated with an increase in caesarean sections and instrumental vaginal births. The real challenge is how best to convey this uncertainty to women to enable them to make an informed choice without compromising the normality of labour.

Sonographic templates of newborn perforator stroke

BACKGROUND

Many paediatric strokes occur in the perinatal period. Improvement in neuroimaging has increased detection in newborns with neurological symptoms.

OBJECTIVE

To define sonographic templates of neonatal stroke in the territory of perforators of the anterior choroidal artery (AChA) and the anterior (ACA), middle (MCA) and posterior (PCA) cerebral arteries.

MATERIALS AND METHODS

In 24 neonates with perforator stroke, we retrospectively studied antenatal and perinatal events. Brain sonography was performed with an 8.5-MHz probe. Only hyperechoic lesions in the thalamus and/or striatum and/or centrum semiovale were included. MRI was obtained using a 1.5-T machine.

RESULTS

We detected 28 perforator strokes in 24 infants (6 preterm): 5 MCA medial striate, 8 MCA lateral striate, 3 MCA centrum semiovale, 4 ACA Heubner's, 5 PCA thalamic arteries, 1 AChA, and 2 hypothalamic perforators. We attributed clinical seizures to stroke in two infants only. Catheter-related embolism (certain in three, possible in six others) and birth trauma (two) were probable causes. Specific conditions were found in six others. Only one infant (in nine evaluated) had an increased prothrombotic risk (fII mutation). In describing the lesions, we focused on the templates of infarction as seen in a parasagittal US sweep. Infarcts were confirmed by MRI in 21 patients.

CONCLUSION

Our study showed that infarct topography can be evaluated reliably with brain sonography. This is important given the asymptomatic character of most lesions.

Induction of reproducible focal ischemic lesions in neonatal mice by photothrombosis

Focal stroke during the perinatal and neonatal period is a significant cause of cognitive and behavioral deficits. Currently, the number of models available to study neonatal brain injury is limited and many are technically difficult to induce in neonatal rodents. We demonstrate a reproducible method to induce a focal ischemic injury in the cerebral cortex of neonatal mice that utilizes the principle of photothrombosis. Postnatal day 7 pups were anesthetized and systemically administered rose bengal (50 mg/kg). Permanent focal ischemia was induced in the medial frontal cortex and somatosensory cortex by irradiating surface blood vessels with a laser (532 nm). By placing a mask having an aperture of defined shape and size on the skull surface, we were able to reliably and reproducibly induce infarcts in discretely defined cortical regions. Further, we demonstrate explicit control of infarct volume by modifying the duration of laser exposure. This tool will provide a means for researchers to safely, easily and noninvasively induce reproducible ischemic lesions in specified regions of the neonatal cortex.

Combination of early perinatal factors to identify near-term and term neonates for neuroprotection

OBJECTIVE

To determine early predictors of abnormal outcome at > or =24 months' age in neonates at risk for hypoxic-ischemic brain injury.

STUDY DESIGN

A prospective cohort study with developmental follow-up of > or =24 months. Infants were selected based on risk factors, and neurologic outcome was determined. Variables affecting the outcome were evaluated with univariate and multivariate methods, and a scoring system was devised to predict adverse outcome.

RESULTS

A total of 41 infants born > or =35 weeks' gestational age with possibility of hypoxic-ischemic insult were enrolled. In all, 39 (95%) had known outcomes, of whom 17 (48%) had an abnormal neurologic outcome, including five deaths. The variables within the first hour of life correlating with the adverse outcome were 1- and 5-minute Apgar scores, intubation in the delivery room and cord/initial base-deficit > or =20 mmol/l. A scoring system was derived based on significant variables, and a score > or =5 had a 90% positive predictive value for abnormal outcome. Seizures, multiorgan failure and abnormal imaging studies were also significantly associated with abnormal outcome.

CONCLUSIONS

The proposed scoring system, being highly predictive of outcome at 24 months' age, may be potentially useful in selecting subjects for preventive or therapeutic interventions to prevent or minimize neurologic morbidity due to hypoxic brain injury.

Perinatal stroke in children with motor impairment: a population-based study

OBJECTIVE

Risk factors for perinatal arterial stroke (PAS) are poorly understood. Most previous studies lack an appropriate control group and include only infants with symptoms in the newborn period. We set out to determine prenatal and perinatal risk factors for PAS.

METHODS

In a population-based, case-control study nested within the cohort of 231 582 singleton infants who were born at >or=36 weeks' gestation in Northern California Kaiser hospitals from 1991 to 1998, we searched electronically for children with motor impairment and reviewed their medical records to identify diagnoses of PAS. Control subjects were randomly selected from the study population. A medical record abstractor reviewed delivery records without knowledge of case status.

RESULTS

The prevalence of PAS with motor impairment was 17/100,000 live births. Of 38 cases, 26 (68%) presented after 3 months of age with hemiparesis or seizures. All 12 newborns with acute stroke symptoms had seizures. A delayed presentation was more common in children with moderate to severe motor impairment than among infants with only mild motor abnormalities (24 of 31 vs 2 of 7). Prepartum risk factors significantly associated with PAS in multivariate analysis were preeclampsia (odds ratio [OR]: 3.6; 95% confidence interval [CI]: 1.1-11.4) and intrauterine growth restriction (OR: 5.3; 95% CI: 1.5-18.6). Newborns with PAS were also at higher risk of delivery complications, such as emergency cesarean section (OR: 6.8; 95% CI: 2.7-16.6), 5-minute Apgar <7 (OR: 23.6; 95% CI: 4.1-237), and resuscitation at birth (OR: 4.5; 95% CI: 1.6-12.3).

CONCLUSIONS

Preeclampsia and intrauterine growth restriction (IUGR) may be independent risk factors for perinatal stroke resulting in motor impairment. Large multicenter studies that include all children with perinatal stroke are needed to determine further the risk factors and outcome of perinatal stroke.

Neonatal seizures and brain damage

There are four unresolved clinical issues at bedside with respect to the recognition, differential diagnosis, prognosis, and treatment of infants who present with seizures. There is also an overriding fifth question which bridges these four clinical issues, based on a laboratory researcher's perspective at the "bench". Given the increasing understanding of the neurobiologic and pathophysiologic explanations for seizures in animal models, one must consider the question of whether neonatal seizures cause brain injury or are a surrogate of injury resulting from other etiologies.

Animal models of neonatal stroke

Neonatal stroke occurs in approximately 1 in 4,000 to 1 in 10,000 newborns, and more than 80% involve the vascular territory supplied by the middle cerebral artery. Neonatal stroke is associated with many acquired and genetic prothrombotic factors, and follow-up studies indicate that as many as two thirds of neonates develop neurologic deficits. In the past two decades unilateral carotid occlusion with 8% hypoxia has been used to study focal and global ischemia in the newborn, and recently a filament model of middle cerebral artery occlusion has been developed. This review describes the results of studies in these two newborn models covering aspects of the injury cascade that occurs after focal ischemia. A likely requirement is that therapeutic efforts be directed less at using thrombolytic therapy and more toward treatment of events associated with reperfusion injury, the inflammatory cascade, and apoptosis. Additional areas of research that have received attention in the past year include inhibition of nitric oxide and free-radical formation, use of iron chelating agents, the potential role of hypoxia-inducible factors and mediators of caspase activity, use of growth factors, hypothermia, and administration of magnesium sulfate.

Prenatal and perinatal determinants of neonatal seizures occurring in the first week of life

To evaluate prenatal and perinatal risk factors for early neonatal seizures, we conducted a case-control study including 100 newborns with neonatal seizures in the first week of life and 204 controls randomly selected from a list of healthy newborns born in the same hospital during the study period. Generalized tonic seizures were the most common seizures observed (29%), although the majority of newborns (71%) experienced more than one type of seizure. The most frequent presumed etiology of neonatal seizures was hypoxic-ischemic encephalopathy (30%). A history of epilepsy in first-degree relatives was found only for cases. Neonatal seizures were found to be associated with maternal disease in the 2 years before pregnancy, mother's weight gain > 14 kg during pregnancy, placental pathology, preeclampsia, low birthweight, low gestational age, and jaundice in the first 3 days of life. The need for cardiopulmonary resuscitation was found only for cases (37%). The causal pathways for neonatal seizures often begin before birth, and some of the factors identified may be preventable.

Demographic and intrapartum characteristics of term pregnancies with early-onset neonatal seizures

OBJECTIVE

To compare the demographic and intrapartum factors of term pregnancies in which early-onset neonatal seizures developed with the characteristics of a large, unselected control population.

STUDY DESIGN

Pregnancies delivered at term (gestational age > or = 37 weeks) in one birthing unit between 1984 and 1995 with a discharge diagnosis of neonatal seizures were identified. Maternal and neonatal charts of these patients were reviewed to confirm the diagnosis of early-onset seizure (EOS) which was defined as a clinical or EEG-diagnosed seizure within 72 hours of life. Demographic and intrapartum factors were compared between these EOS cases and all singleton term pregnancies delivered over the same time period in which there was no EOS. A regression model was then developed to determine factors predictive of EOS.

RESULTS

Of 80,561 total deliveries during the 11-year study period, there were 64,340 control and 62 EOS (0.1%) deliveries. Regression modeling identified NICU admission, depressed 1- and 5-minute Apgar scores, and neonatal intubation as predictors of EOS, but not operative vaginal, vaginal breech, or cesarean delivery.

CONCLUSION

Depressed condition at birth and/or the requirement for NICU care was the most important risk associated with early seizures in term infants.

Intrapartum fever and unexplained seizures in term infants

OBJECTIVE

Early-onset neonatal seizures are a strong predictor of later morbidity and mortality in term infants. Although an association of noninfectious intrapartum fever with neonatal seizures in term infants has been reported, it was based on only a small number of neonates with seizures. We therefore conducted a case control study to investigate this association further.

METHODS

All term infants with neonatal seizures born at Brigham and Women's Hospital between 1989 and 1996 were identified. For this study, cases consisted of all term neonates with a confirmed diagnosis of seizure born after a trial of labor for whom no proximal cause of seizure could be identified. Infants with sepsis or meningitis were excluded. Four controls matched by parity and date of birth were identified for each case. The rate of intrapartum maternal temperature >100.4 degrees F was compared for case infants and controls. Potential confounding was controlled in logistic regression analysis.

RESULTS

Cases comprised 38 term infants with unexplained seizures after a trial of labor. We identified 152 controls. Infants with seizures were more likely to be born to mothers who were febrile during labor (31.6% vs 9.2%). In almost all cases, the fever developed during labor (94.7% cases, 97.4% controls). At admission, mothers of infants with seizures were not significantly more likely to have factors associated with concern about infection such as a white blood cell count >15 000/mm(3) (28. 9% vs 19.1%) and premature rupture of the membranes (15.8% vs 17.8%). In a logistic regression analysis controlling for confounding factors, intrapartum fever was associated with a 3.4-fold increase in the risk of unexplained neonatal seizures (odds ratio = 3.4, 95% confidence interval = 1.03-10.9).

CONCLUSION

Our data indicate that intrapartum fever, even when unlikely to be caused by infection, is associated with a fourfold increase in the risk of unexplained, early-onset seizures in term infants.

Repetitive intermittent hypoxia-ischemia and brain damage in neonatal rats

OBJECTIVE

To know the effect of brief-repetitive intermittent hypoxia-ischemia on the development of perinatal brain damage.

STUDY DESIGN

Seven-day-old Wistar rats underwent ligation of the unilateral common carotid artery. The animals were allocated to three groups (n=12 in each group) and exposed to 8% oxygen as follows: group A: continuous exposure for 180 min; group B: continuous exposure for 90 min; and group C: 10 min of exposure repeated at 10-min intervals over a period of 180 min (total exposure time, 90 min). Seventy-two hours after exposure to hypoxia, the cerebral cortex was examined to assess the degree of neuronal necrosis and brain damage was classified into four grades of severity, 0-3. To evaluate the extent of brain damage, we used immunohistochemical staining with TIB-128 antibody, which reacts to MAC-1 antigen specific to microglia, and observed the glial reaction in the cerebral cortex, hippocampus, thalamus, and striatum.

RESULTS

All the brain damage observed in groups A-C occurred on the side where the ligation was performed. The most severe damage was found in group A animals, of which seven showed significant neuronal necrosis, having a grade 2 or more advanced lesion. In group B, neuronal necrosis was modest, with only one animal having a grade 2 lesion. In group C, a significant neuronal necrosis was found in six animals despite having the same period of hypoxic exposure as those in group B. MAC-1 positive cells appeared in the cerebral cortex of histologically damaged animals and extended to the hippocampus, thalamus, and striatum in severely damaged animals from groups A, B, and C.

CONCLUSION

Examination of the neonatal rat model suggested that repetitive and intermittent, rather than continuous hypoxia-ischemia, causes pronounced damage in the immature brain.

The relationship between nucleated red blood cell counts and early-onset neonatal seizures

OBJECTIVE

This study was undertaken to better define the timing of neurologic insult in neonates with early-onset seizures through evaluation of neonatal nucleated red blood cell levels.

STUDY DESIGN

Medical records and the International Classification of Diseases, Ninth Revision codes were used to identify all term neonates with neonatal convulsions who were delivered at our institution (January 1, 1990-December 31, 1995). Each neonate with early-onset seizures was matched to the next 3 neonates who met the following criteria: gestational age > or =37 weeks, no early-onset seizures, birth weight > or =800 g, umbilical artery pH > or =7.25, and a 5-minute Apgar score >7. Demographic characteristics, clinical factors, and mean initial nucleated red blood cell counts were compared between groups.

RESULTS

During the 6-year study period, there were a total of 36, 490 singleton term deliveries of infants who were alive at birth. Forty-five (0.1%) of these neonates had early-onset seizures. Thirty neonates with early-onset seizures met the inclusion criteria. Mean nucleated red blood cell counts (number of nucleated red blood cells per 100 white blood cells) for neonates with early-onset seizures were significantly increased compared with those of control neonates (18.4 +/- 22.0 vs 4.6 +/- 4.5; P <.0008).

CONCLUSIONS

Our findings are suggestive of the hypothesis that neurologic injury leading to early-onset seizures often occurs before the intrapartum period.

Perinatal cortical infarction within middle cerebral artery trunks

AIM

To define neonatal pial middle cerebral artery infarction.

METHODS

A retrospective study was made of neonates in whom focal arterial infarction had been detected ultrasonographically. A detailed study was made of cortical middle cerebral artery infarction subtypes.

RESULTS

Forty infarctions, with the exception of those in a posterior cerebral artery, were detected ultrasonographically over a period of 10 years. Most were confirmed by computed tomography or magnetic resonance imaging. Factor V Leiden heterozygosity was documented in three. The onset was probably antepartum in three, and associated with fetal distress before labour in one. There were 19 cases of cortical middle cerebral artery stroke. The truncal type (n=13) was more common than complete (n = 5) middle cerebral artery infarction. Of six infarcts in the anterior trunk, four were in term infants and five affected the right hemisphere. Clinical seizures were part of the anterior truncal presentation in three. One of these infants, with involvement of the primary motor area, developed a severe motor hemisyndrome. The Bayley Mental Developmental Index was above 80 in all of three infants tested with anterior truncal infarction. Of seven patients with posterior truncal infarction, six were at or near term. Six of these lesions were left sided. Clinical seizures were observed in three. A mild motor hemisyndrome developed in at least three of these infants due to involvement of parieto-temporal non-primary cortex.

CONCLUSIONS

Inability to differentiate between truncal and complete middle cerebral artery stroke is one of the explanations for the reported different outcomes. Severe motor hemisyndrome can be predicted from neonatal ultrasonography on the basis of primary motor cortex involvement. Clinical seizures were recognised in less than half of the patients with truncal infarction; left sided presentation was present in the posterior, but not the anterior truncal type of infarction. Asphyxia is a rare cause of focal arterial infarction.

Does the onset of neonatal seizures correlate with the timing of fetal neurologic injury?

The onset of seizures after birth has been considered evidence of an intrapartum asphyxial event. The present study was undertaken to determine whether the timing of neonatal seizures after birth correlated with the timing of a fetal asphyxial event. Thus, singleton term infants diagnosed with hypoxic ischemic encephalopathy and permanent brain injury had a mean birth to seizure onset interval of 9.8 +/- 17.7 (range 1-90) hours. When these infants were categorized according to their fetal heart rate (FHR) patterns, the acute group (normal FHR followed by a sudden prolonged FHR deceleration that continued until delivery) tended to have earlier seizures than infants did within the tachycardia group (normal FHR followed by tachycardia, repetitive decelerations, and diminished variability) and the preadmission group (persistent nonreactive FHR pattern intrapartum). These seizure intervals were as follows: acute, 6.6 +/- 18.0 (range 1-90) hours; tachycardia, 11.1 +/- 17.1 (range 1-61) hours; and preadmission, 11.8 +/- 17.9 (range 1-79) hours (p < 0.05). But the range varied widely and no group was categorically distinct. In conclusion, the onset of neonatal seizures after birth does not, in and of itself, appear to be a reliable indicator of the timing of fetal neurologic injury.

Meconium-stained amniotic fluid and the meconium aspiration syndrome. An update

Over the past 5 years, increasing understanding about the pathophysiology of meconium-stained amniotic fluid (MSAF) and the meconium aspiration syndrome (MAS) has occurred. Many new therapies are being used in an attempt to prevent MAS and to treat the disorder. The authors review the current status of knowledge concerning the MSAF and MAS and management of these entities.

Unilateral neonatal cerebral infarction in full term infants

AIMS

To determine the prevalence of unilateral neonatal cerebral infarction in infants born at 32 weeks gestation and above; to describe the clinical course, imaging results, and outcome of neonatal cerebral infarction; and to investigate possible aetiology.

METHODS

Twelve cases of unilateral neonatal cerebral infarction were identified from neonatal unit records for the years 1987-93. Each case was matched with two controls.

RESULTS

All cases of neonatal cerebral infarction occurred in full term infants. The prevalence was around 1 in 4000, and neonatal cerebral infarction was found in 12% of infants presenting with neonatal seizures. Cerebral ultrasound scans failed to demonstrate lesions seen by computed tomography in nine of 12 cases. Cases were more likely than controls to require assisted ventilation for resuscitation at birth (OR 7.0, 95% confidence interval 1.04-53.5), but Apgar scores at 5 minutes were no different. One infant with neonatal cerebral infarction developed a hemiparesis, the other 11 had normal motor development when assessed at 11-60 (median 33) months. None had overt cognitive deficits or persisting seizure disorder.

CONCLUSIONS

Neonatal cerebral infarction is a relatively common cause of neonatal seizures, but the aetiology remains unclear. Parents need to be made aware of possible neurological sequelae, but most cases in this series had a normal outcome.