Seizures In Term Infants Research Articles

Falls in oxygen saturations accompany electrographic seizures in term neonates: an observational study

BackgroundEffective seizure detection is important however, clinical signs of seizure activity may be subtle in neonates. This study aimed to systematically investigate SpO2 and respiratory pattern changes associated with EEG seizures in term-born neonates.MethodAn observational study in term neonates at risk of seizures admitted to a single tertiary level neonatal intensive care unit. Synchronised high-resolution physiological data (ECG, pulse oximetry, respiration) and EEG/amplitude-integrated EEG (aEEG) monitoring were recorded. Sections of traces with evidence of clear EEG seizure activity were compared with physiological data recorded at the same time.Results22/44 (50%) neonates who had aEEG monitoring were noted to have electrographic seizures. Physiologic download measurements were available for 11 of these neonates. In nine of these, an acute drop in oxygen saturation (SpO2) of at least 5% was noted in at least one seizure. Accompanying apnoeas were noted in three neonates.ConclusionAcute decreases in SpO2 were seen in term neonates associated with seizures and these were not always accompanied by an apnoeic episode. Physiologic download in association with EEG monitoring may assist in improving seizure detection. Unexplained drops in SpO2 could indicate further investigation for possible seizures in at-risk neonates.ImpactA decrease in blood oxygen saturation (SpO2) associated with EEG seizures can occur in term infants with HIE or perinatal stroke.Drops in SpO2 associated with EEG seizures in term infants with HIE or stroke may occur in the absence of apnoeas.Unexplained acute falls in SpO2 in sick neonates may suggest possible seizures.Drops in SpO2 associated with seizures in term infants can occur over less than 3 minutes.Physiological monitoring alongside EEG monitoring could help to improve seizure detection.

NEONATAL SEIZURES: ETIOLOGY, TREATMENT AND PROGNOSIS

Introduction: Seizures are one of the most common pathologies in newborns. Their incidence is 1.5–3.5/1000 for term infants and 10–130/1000 for preterms. The most common causes of seizures in term infants are hypoxic-ischemic encephalopathy (HIE), cerebrovascular insult (CVI), cerebral malformations (CM), and metabolic disorders. For preterm infants: intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL) and infections. Clinical characteristics are diverse and subtle, and subclinical forms are common. The drug of the first choice is phenobarbitone. Newborns with seizures are more prone to developing neurological disturbances such as epilepsy and cerebral palsy.
 Methods: This is a clinical, observational research, one-year, retrospective, cross-sectional study conducted in the Department of neonatal intensive care and neonatology of the Clinic of Pediatrics KCUS. The study included 43 newborns who met the inclusion criteria.
 Results: We found that 7.19% of hospitalized newborns had seizures. A number of seizures were recorded in the group of term infants with an earlier time of seizures. The most common etiological causes were: HIE, IVH, infections, and CM. There was a frequent occurrence of metabolic disorders such as acidosis, blood sugar, and mineral (Ca, K, Na, and Mg) disorders. The median of the first day of onset of seizures in full-term infants is on the fourth day, while in premature infants it is on the sixth day of life. Phenobarbitone was mainly used to stop seizures, with great success. Overall mortality in children with seizures was 37.21%.
 Conclusions: Seizures are common in newborns, which, depending on the etiological cause, increase mortality, especially in preterm infants. Seizures in term infants occur earlier than in premature infants. The most common etiology of seizures in term infants are infections, hypoxemic-ischemic encephalopathy, intracranial hemorrhage, cerebral malformations, and cerebrovascular insult. In premature infants these are hypoxemic-ischemic encephalopathy, intracranial bleeding, and infections. In the initial treatment of neonatal convulsions, phenobarbitone is most often used, which has proven to be successful in the majority of cases.

Prognostic Factors of Developmental Outcome in Neonatal Seizures in Term Infants

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

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

Objective To identify independent prognostic indicators and design a predictive scoring system for neurodevelopmental outcome for term infants who experienced clinical neonatal seizures. Study Design: Retrospective analysis of 120 term infants who experienced clinical neonatal seizures between July 1991 and June 2007 in a single academic pediatric neurology practice. Logistic regression analysis was applied to determine the independent prognostic indicators of an adverse outcome, which was defined as death, cerebral palsy, global developmental delay, and/or epilepsy. These indicators were then used to develop a scoring system. Results: A total of 53 infants had a normal outcome, 56 survived with one or more neurodevelopmental impairments (31 had cerebral palsy, 41 had global developmental delay, and 29 had epilepsy), and 11 died. Eleven variables were associated with adverse outcome on univariate analysis, but only method of delivery, time of seizure onset, seizure type, EEG background findings, and etiology were independent predictors on logistic regression analysis. A five-point scoring system was devised using these independent predictors with a sensitivity of 81.1% and a specificity of 84.0%. Conclusions: In term infants, delivery via cesarean section, experiencing a seizure during the first 24 h of life, presenting with a seizure other than focal clonic, showing a moderately or severely abnormal EEG background, and having certain specific etiologies were the apparent major determinants for an adverse outcome.

Epidemiology of seizures in term infants

Newborn infants presenting with seizures are infrequent, but a major concern because of their long-term outcomes. In this issue of The Journal, Glass et al provide precise estimates for seizure occurrence after term birth using a California data set of over 2 million births. The incidence of seizures was about 1 per 1000 live births. The risks of newborn seizures were increased for maternal age over 40, maternal diabetes, deliveries at ≥42 weeks, catastrophic deliveries, and maternal infection. This information should help alert pediatricians to infants who are at increased risk of seizures following term birth. Newborn infants presenting with seizures are infrequent, but a major concern because of their long-term outcomes. In this issue of The Journal, Glass et al provide precise estimates for seizure occurrence after term birth using a California data set of over 2 million births. The incidence of seizures was about 1 per 1000 live births. The risks of newborn seizures were increased for maternal age over 40, maternal diabetes, deliveries at ≥42 weeks, catastrophic deliveries, and maternal infection. This information should help alert pediatricians to infants who are at increased risk of seizures following term birth.

Maternal Risk Factors for Term Neonatal Seizures: Population-Based Study in Colorado, 1989—2003

Neonatal seizures in term infants are rare but have important potential implications for brain development. Risk factors for neonatal seizures in term infants have been less well defined than those among preterm infants. To evaluate the relationship between maternal risk factors and neonatal seizures in the first 72 hours of life in term infants, a case-control study using the Colorado Birth Certificate Registry was conducted. Term neonates in all hospitals in Colorado with and without seizures in the first 72 hours were studied. After adjusting for vaginal delivery in the setting of herpes infection and post-term delivery, preexisting diabetes in the mother (odds ratio 4.30, 95% confidence interval 1.64-11.27, P < .01) and fetal distress (odds ratio 5.88, 95% confidence interval 4.60-7.13, P < .0001) were independent risk factors for neonatal seizures in term infants. These findings are confirmatory of previous reports that maternal preexisting diabetes and fetal distress increase the risk of neonatal seizure in term infants. Although we cannot establish the pathophysiology of neonatal seizures from this analysis, hypoxic-ischemic brain injury and hypoglycemia in infants of diabetic mothers are known causes of neonatal seizures that can be represented in this analysis by fetal distress and maternal preexisting diabetes, respectively. Maternal diabetic vasculopathy can also be a contributing factor.

Prediction of Seizures in Asphyxiated Neonates

Early continuous video electroencephalography was used to detect seizures in term infants at high risk of hypoxic ischemic encephalopathy (HIE) in a study at University College Cork, and St Vincent’s University Hospital, Dublin, Ireland.

Clinical and Epidemiologic Characteristics of Viral Infections in a Neonatal Intensive Care Unit During a 12-Year Period

The incidence of viral infections in patients treated in the neonatal intensive care unit (NICU) is not well-known. We summarized the data of all patients with laboratory-confirmed viral infections admitted at the NICU of our hospital during the period of 1992-2003. To determine the incidence of viral infections among infants hospitalized in a NICU, the associated clinical manifestations and their outcome. Retrospective analysis of epidemiologic, virologic and clinical data from infants with proven viral infection. The diagnosis viral infection was confirmed by positive viral culture and/or polymerase chain reaction from clinical samples. Viral infection was confirmed in 51 of 5396 infants (1%) admitted to the NICU; 20 (39%) had an enterovirus and parechovirus (EV/PEV) infection, 15 (29%) a respiratory syncytial virus (RSV) infection, 5 (10%) a rotavirus infection, 3 (6%) a cytomegalovirus (CMV) infection, 2 (4%) an adenovirus infection, 2 (4%) a parainfluenza virus infection, 2 (4%) a herpes simplex virus infection, 1 (2%) a rhinovirus infection and 1 (2%) a rubella virus infection. Three of the infants presented at birth with symptomatic rubella virus, CMV or herpes simplex virus infection. RSV infection developed mostly in hospitalized infants (60%), and 93% of infections occurred during the winter (November-March). The clinical presentations of EV/PEV disease were sepsis-like illness, prolonged seizures in term infants and gastrointestinal disease in preterm infants. RSV, parainfluenza virus, rhinovirus and CMV caused respiratory disease, predominantly in preterm infants. Gastrointestinal disease was seen only in preterm infants with adenovirus, rotavirus or EV/PEV infection. Mortality and serious sequelae were high in patients infected with EV/PEV (10 and 15%, respectively). The incidence of viral infection in the NICU was 1%. Enteroviral infections were the most frequently diagnosed infections, occurred often in term infants born at home and presented with sepsis-like illness or seizures. Preterm infants hospitalized from birth mainly developed gastrointestinal disease caused by rotavirus and adenovirus infection or respiratory disease caused by RSV, parainfluenza and CMV infection. Enteroviruses were responsible for the highest mortality and development of serious sequelae.

Neonatal encephalopathy: etiology and outcome

The original study by Badawi et al. investigated risk factors for neonatal encephalopathy (NE) and/or neonatal seizures in term infants. They used a broad definition appropriate for examining etiology and capable of asking such questions as: what proportion of NE arises after birth asphyxia? The answer was: some, but not much. That study was, and still is, the only large population-based investigation of multiple potential risk factors for NE, and it identified novel risk factors such as maternal thyroid disease, family history of seizures, and placental abnormalities. Several of these factors have been found to be risk factors for NE, neonatal seizures, or cerebral palsy (CP) in other studies.

Origin and Timing of Brain Lesions in Term Infants With Neonatal Encephalopathy

It is not clear whether intrapartum asphyxia is an important factor in neonatal encephalopathy and seizures in term infants. Antenatal factors have been implicated, but there is no firm evidence that brain damage occurs in utero. This study examined the proposal that neonatal encephalopathy and early postnatal seizures, or both, are sequelae of early adverse antenatal events. Cerebral magnetic resonance imaging (MRI) or autopsy was carried out in 351 full-term infants having encephalopathy and/or seizures within 72 hours of birth. Infants with major congenital malformations or known chromosomal disorders were excluded. The 261 infants placed in group 1 had a diagnosis of neonatal encephalopathy, with or without seizures, as well as evidence of perinatal asphyxia. The 90 group 2 infants presented with seizures but failed to meet diagnostic criteria for encephalopathy. Cerebral MRI disclosed evidence of acutely evolving lesions not related to established injury or atrophy in 80% of group 1 infants. These lesions, which usually were bilateral, were consistent with a hypoxic-ischemic insult. In addition to white matter, abnormalities were found in the basal ganglia, thalamus, or cortex. Only 2 group 1 infants, fewer than 1% of the total, had evidence of established injury. Three of 21 autopsies showed, in addition to an acutely evolving lesion, very small foci of established gliosis in the periventricular white matter. Acute ischemic or hemorrhagic lesions were found in 69% of group 2 infants. Two infants (3%) had, in addition, changes of antenatal injury. Thirteen of the 28 remaining group 2 infants had MRI findings of a specific nonhyoxic-ischemic condition. The other 15 infants had normal scans. Seven of 10 infants with no specific diagnosis continued to have seizures. Antenatal risk factors that were significantly more frequent in infants having apparent antenatal lesion or disorders of genetic or neurometabolic origin included a family history of seizures or neurologic disorder, low birth weight, head circumference below the 10th percentile, and low maternal age. In this study, more than 90% of term infants with neonatal encephalopathy and/or early seizures had evidence of a perinatally acquired insult. Established brain injuries acquired before birth were quite infrequent. The findings do not rule out the change that antenatal (or genetic) factors could predispose some infants to perinatal brain injury.

Origin and timing of brain lesions in term infants with neonatal encephalopathy

The role of intrapartum asphyxia in neonatal encephalopathy and seizures in term infants is not clear, and antenatal factors are being implicated in the causal pathway for these disorders. However, there is no evidence that brain damage occurs before birth. We aimed to test the hypothesis that neonatal encephalopathy, early neonatal seizures, or both result from early antenatal insults. We used brain MRI or post-mortem examination in 351 fullterm infants with neonatal encephalopathy, early seizures, or both to distinguish between lesions acquired antenatally and those that developed in the intrapartum and early post-partum period. We excluded infants with major congenital malformations or obvious chromosomal disorders. Infants were divided into two groups: those with neonatal encephalopathy (with or without seizures), and evidence of perinatal asphyxia (group 1); and those without other evidence of encephalopathy, but who presented with seizures within 3 days of birth (group 2). Brain images showed evidence of an acute insult without established injury or atrophy in 197 (80%) of infants in group 1, MRI showed evidence of established injury in only 2 infants (<1%), although tiny foci of established white matter gliosis, in addition to acute injury, were seen in three of 21 on post-mortem examination. In group 2, acute focal damage was noted in 62 (69%) of infants. Two (3%) also had evidence of antenatal injury. Although our results cannot exclude the possibility that antenatal or genetic factors might predispose some infants to perinatal brain injury, our data strongly suggest that events in the immediate perinatal period are most important in neonatal brain injury.

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

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. 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. 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. 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.

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. 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. 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). 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.

Changes in risk factors for hypoxic-ischaemic seizures in term infants.

Term infants with seizures and evidence of perinatal asphyxia were prospectively identified in 1 city and 2 time periods: 1978-1981 and 1991. Infants with multiple congenital abnormalities, hypocalcaemia or infection were excluded. Although there was little change in the overall incidence of neonatal seizures between 1978-1981 (1.9 per 1,000) and 1991 (1.78 per 1,000, N.S.) there was a marked reduction in small for dates infants with seizures: 8 of 19 infants in 1978-1981 compared to none of 16 in 1991 (p < 0.005). In contrast, infants > or = 41 weeks continued to show a markedly increased risk for asphyxia (relative risk 4.48, 95% CI: 1.7-12.3). The mechanism of this improved outcome for small for gestational age infants is unknown, but speculatively may be due to improved obstetric monitoring techniques allowing early identification of compromised infants.

Neonatal dural sinus thrombosis

Dural sinus thrombosis in the newborn period has been infrequently documented and its clinical presentation remains obscure. Seventeen patients, all of whom were born at term with dural sinus thrombosis diagnosed in the neonatal period, were retrospectively identified and reviewed. Diagnosis was determined by unenhanced computed tomography which demonstrated a dense sagittal sinus with concomitant small ventricles. Two patients had ancillary studies (i.e., cerebral angiography and nuclear flow scan) which confirmed the diagnosis. Only 4 patients had evidence of perinatal asphyxia. Three patients were identified as having associated conditions known to predispose them to dural sinus thrombosis. None of the patients tested had an identifiable hypercoagulable state. Neonatal seizures were the initial presentation in 15 patients. Seizure onset predominantly occurred during the first week of life. Subsequent examinations were available in all 17 patients and ranged up to 6 years. Only 3 patients had seizures beyond the neonatal period. In 11 of 12 infants with no history of perinatal asphyxia, neurodevelopmental outcomes were normal. Two of 4 infants with perinatal asphyxia had neurologic sequelae. Dural sinus thrombosis represents an important and under-recognized cause of neonatal seizures in term infants. In the absence of perinatal asphyxia, normal neurodevelopmental outcome is likely and the risk of seizure recurrence is low.