Neonatal seizures associated with cerebral lesions shown by magnetic resonance imaging

Utility of Rapid Sequence Magnetic Resonance Imaging in Guiding Management of Patients With Neonatal Seizures

OBJECTIVE

To determine whether the use of rapid sequence magnetic resonance imaging (rsMRI) is associated with improved efficiency of care when managing infants with suspected neonatal onset seizures.

METHODS

We conducted a preintervention and postintervention study of the use of rsMRI in term infants with suspected neonatal onset seizures without evidence of hypoxic ischemic encephalopathy. Study patients were collected from a contemporary cohort from 2016 to 2017 and were compared with a historical cohort from 2014. The primary outcome was hospital length of stay. Secondary outcomes included use of other imaging modalities (head ultrasound, computed tomography [CT], and MRI), use of antiseizure medications at the time of discharge, and cost of hospitalization. Continuous variables were compared using the Mann-Whitney U test and categorical variables using the Fisher's exact or χ² tests. A two-tailed P < 0.05 was considered statistically significant.

RESULTS

Ninety-five patients met inclusion criteria, 47 in the preintervention and 48 in the postintervention group. Incorporation of the protocol-guided rsMRI in the evaluation of patients with neonatal seizures was associated with decreased use of CT scans (34% vs 10%, P = 0.007) and full MRIs (85% vs 62%, P = 0.019). Use of head ultrasound, length of stay, and costs were not different between groups.

CONCLUSIONS

In patients with neonatal seizures, rsMRI was not associated with a reduced hospital length of stay. The use of rsMRI resulted in fewer neonates receiving CT scans during their hospitalization. rsMRI may hasten the identification of stroke or hemorrhage in neonates with seizures.

Brain Ultrasonography Findings in Neonatal Seizure; a Cross-sectional Study

INTRODUCTION

Screening of newborns with seizure, who have curable pathologic brain findings, might be able to improve their final outcome by accelerating treatment intervention. The present study aimed to evaluate the brain ultrasonography findings of newborns hospitalized with complaint of seizure.

METHODS

The present cross-sectional study designed to evaluate brain ultrasonography findings of hospitalized newborns complaining seizure. Neonatal seizure was defined as presence of tonic, clonic, myoclonic, and subtle attacks in 1 - 28 day old newborns.

RESULTS

100 newborns with the mean age of 5.82 ± 6.29 days were evaluated (58% male). Most newborns were in the < 10 days age range (76%), term (83%) and with normal birth weight (81%). 22 (22%) of the ultrasonography examinations showed a pathologic finding. A correlation was only found between birth age and probability of the presence of a pathologic problem in the brain as the frequency of these problems was significantly higher in pre-term newborns (p = 0.023).

CONCLUSION

Based on the findings of the present study, frequency of pathologic findings in neonatal brain ultrasonography was 22%. Hemorrhage (12%) and hydrocephaly (7%) were the most common findings. The only factor correlating with increased probability of positive findings was the newborns being pre-term.

The aetiology of neonatal seizures and the diagnostic contribution of neonatal cerebral magnetic resonance imaging

AIM

The aim of this study was to delineate aetiologies and explore the diagnostic value of cerebral magnetic resonance imaging (MRI) in addition to cranial ultrasonography (cUS) in infants presenting with neonatal seizures.

METHOD

This retrospective cohort study comprised infants (gestational age 35.0-42.6wks) with seizures, confirmed by either continuous amplitude-integrated electroencephalography (aEEG) or standard EEG and admitted during a 14-year period to a level three neonatal intensive care unit (n=378; 216 males, 162 females; mean [SD] birthweight 3334g [594]). All infants underwent cUS and MRI (MRI on median of 5 days after birth, range 0-58d) within the first admission period.

RESULTS

An underlying aetiology was identified in 354 infants (93.7%). The most common aetiologies identified were hypoxic-ischaemic encephalopathy (46%), intracranial haemorrhage (12.2%), and perinatal arterial ischaemic stroke (10.6%). When comparing MRI with cUS in these 354 infants MRI showed new findings which did not become apparent on cUS, contributing to a diagnosis in 42 (11.9%) infants and providing additional information to cUS, contributing to a diagnosis in 141 (39.8%). cUS alone would have allowed a diagnosis in only 37.9% of infants (134/354).

INTERPRETATION

Cerebral MRI contributed to making a diagnosis in the majority of infants. In 11.9% of infants the diagnosis would have been missed if only cUS were used and cerebral MRI added significantly to the information obtained in 39.8% of infants. These data suggest that cerebral MRI should be performed in all newborn infants presenting with EEG- or aEEG-confirmed seizures.

Changing pattern of perinatal brain injury in term infants in recent years

Perinatal brain injury in term infants remains a significant clinical problem. Recently a change appears to have occurred in the pattern of such injuries. We sought to characterize the incidence, etiology, clinical manifestations, and outcomes of these injuries. A retrospective chart review identified clinical characteristics of neuroimaging, electroencephalography, and placental pathologic findings. Perinatal depression was defined as hypotonia and the need for respiratory support. From January 2004-December 2009, 29,597 term deliveries occurred. Brain injuries in 33 infants (live term births) included hypoxic-ischemic encephalopathy (n = 8; 0.27/1000), subdural hemorrhage (n = 10; 0.34/1000), intraventricular/intraparenchymal hemorrhage (n = 5; 0.17/1000), and focal cerebral infarctions (n = 4; 0.14/1000). Thirteen of 33 infants (39%) were triaged to a regular nursery. Delayed presentations included apnea (n = 6), desaturation episodes (n = 3), and seizures (n = 4). Twenty of 33 (61%) were admitted directly to the neonatal intensive care unit because of perinatal depression or evolving hypoxic-ischemic encephalopathy. Clinical signs included seizures (n = 12) and apnea (n = 2). Nine of 19 manifested electroencephalographic seizures. Pathology included chorioamnionitis (n = 7) and fetal thrombotic vasculopathy (n = 5). The latter was associated with focal cerebral infarctions in 3/4 cases. Most cases attributable to perinatal brain injury, except for evolving hypoxic-ischemic encephalopathy, are not identified according to any perinatal characteristics until the onset of signs, limiting opportunities for prevention.

Apgar Scores and Long-Term Risk of Epilepsy

BACKGROUND

Low Apgar scores are associated with high risk of neonatal death, cerebral palsy, and mental retardation, but the association between Apgar scores and long-term risk of epilepsy remains unresolved.

METHODS

We carried out a population-based cohort study of 1,538,732 live newborns in Denmark between 1 January 1978 and 31 December 2002 by using national registers. The Apgar scores at 1 or 5 minutes were recorded by midwives following standardized procedures. We obtained information on epilepsy by linking the cohort with the National Hospital Register. Cohort members were followed from birth until onset of epilepsy, death, emigration, or 31 December 2002, whichever came first.

RESULTS

The incidence rate of epilepsy increased consistently with decreasing Apgar scores. The incidence rate of epilepsy was 628 per 100,000 person-years for those with 5-minute Apgar scores of 1 to 3 and 86 per 100,000 person-years for those with a score of 10; the resulting incidence rate ratio was 7.1 (95% confidence interval = 5.8-8.8). The incidence rate ratios of epilepsy associated with low Apgar scores were particularly high in early childhood but remained high into adulthood. The association did not change after excluding children with cerebral palsy, congenital malformations, or a parental history of epilepsy.

CONCLUSIONS

Neonates with a suboptimal Apgar score have a higher risk of epilepsy that lasts into adult life. These findings suggest that prenatal or perinatal factors play a larger role in the etiology of epilepsy than has previously been recognized.

The current etiologic profile and neurodevelopmental outcome of seizures in term newborn infants

OBJECTIVES

The objectives of this study were to delineate the etiologic profile and neurodevelopmental outcome of neonatal seizures in the current era of neonatal intensive care and to identify predictors of neurodevelopmental outcome in survivors.

METHODS

Eighty-nine term infants with clinical neonatal seizures underwent neurologic examination, electroencephalography (EEG), neuroimaging, and extensive diagnostic tests in the newborn period. After discharge, all infants underwent regular neurologic evaluations and, at 12 to 18 months, formal neurodevelopmental testing. We tested the prognostic value of seizure etiology, neurologic examination, EEG, and neuroimaging.

RESULTS

Etiology was found in 77 infants. Global cerebral hypoxia-ischemia, focal cerebral hypoxia-ischemia, and intracranial hemorrhage were most common. Neonatal mortality was 7%; 28% of the survivors had poor long-term outcome. Association between seizure etiology and outcome was strong, with cerebral dysgenesis and global hypoxia-ischemia associated with poor outcome. Normal neonatal period/early infancy neurologic examination was associated with uniformly favorable outcome at 12 to 18 months; abnormal examination lacked specificity. Normal/mildly abnormal neonatal EEG had favorable outcome, particularly if neonatal neuroimaging was normal. Moderate/severely abnormal EEG, and multifocal/diffuse cortical or primarily deep gray matter lesions, had a worse outcome.

CONCLUSIONS

Mortality associated with neonatal seizures has declined although long-term neurodevelopmental morbidity remains unchanged. Seizure etiology and background EEG patterns remain powerful prognostic factors. Diagnostic advances have changed the etiologic distribution for neonatal seizures and improved accuracy of outcome prediction. Global cerebral hypoxia-ischemia, the most common etiology, is responsible for the large majority of infants with poor long-term outcome.

The Scottish Perinatal Neuropathology Study-clinicopathological correlation in stillbirths

OBJECTIVE

To examine the neuropathology of fetuses dying before birth, to determine the timing of any brain damage seen and to ascertain clinical associations of pre-existing brain damage.

DESIGN

Population-based observational study.

SETTING

All 22 delivery units within Scotland, 1995-1998.

SAMPLE

All stillborn fetuses > or =24 weeks of gestation excluding those with chromosomal abnormality or central nervous system/cardiothoracic malformation.

METHODS

Clinical detail was collected on all stillborn fetuses. Requests for postmortem included separate request for detailed neuropathological examination. Stillborn fetuses were classified as full term antepartum (normal growth/growth restricted), preterm antepartum (normal growth/growth restricted), intrapartum (full term/preterm), multiple births and stillborn fetuses following abruptions. Clinicopathological correlation attempted to define the timing of brain insult. Placentas were examined for each case where available.

MAIN OUTCOME MEASURES

Presence of established and/or recent brain damage. RESULTS Clinical details were available for 471 stillborn fetuses, and detailed neuropathology was possible in 191 cases. Of these 191, 13 were multiple births, 9 died following abruption, 12 were intrapartum deaths and 157 were antepartum stillborn fetuses (99 preterm and 58 full term). Recent or established brain damage was seen in 66% of the entire cohort. Thirty-five percent of all cases showed well-established hypoxic damage predating the last evidence of fetal life, and this was more common in preterm fetuses (P = 0.015), those fetuses with evidence of recent damage (P < 0.001), in pregnancies complicated by pregnancy-induced hypertension (P = 0.044) and those in whom the placenta was <10th centile (P = 0.002).

CONCLUSIONS

Brain damage is commonly seen in stillborn infants, and in around one-third of cases, damage predates the period immediately before death. Factors suggesting suboptimal placental function are associated with such damage. Early identification of placental impairment may lead to improved pregnancy outcome.

Suppression of BDNF-induced expression of neuropeptide Y (NPY) in cortical cultures by oxygen-glucose deprivation: a model system to study ischemic mechanisms in the perinatal brain

The aim of this study was to establish a culture system that can serve as a model to study hypoxic-ischemic mechanisms regulating the functional expression of NPY neurons in the perinatal brain. Using an aggregate culture system derived from the rat fetal cortex, we defined the effects of oxygen and glucose deprivation on NPY expression, using BDNF-induced production of NPY as a functional criterion. NPY neurons exhibited a differential susceptibility to oxygen and glucose deprivation. Although the neurons could withstand oxygen deprivation for 16 hr, they were dramatically damaged by 8 hr of glucose deprivation and by 1-4 hr of deprivation of both oxygen and glucose (N+Glu-). One-hour exposure to N+Glu- led to a transient inhibition ( approximately 50%) of NPY production manifesting within 24 hr and recovering by 5 days thereafter, a 2-hr exposure to N+Glu- led to a sustained inhibition (50-75%) manifesting 1-5 days thereafter, and a 4-hr exposure to N+Glu- led to a total irreversible suppression of BDNF-induced production of NPY manifesting within 24 hr and lasting 8 days after re-supply of oxygen and glucose. Moreover, 1-hr exposure to N+Glu- led to a substantial and 4-hr exposure led to a total disappearance of immunostaining for MAP-2 and NPY but not for GFAP; indicating that neurons are the primary cell-type damaged by oxygen-glucose deprivation. Analysis of cell viability (LDH, MTT) indicated that progressive changes in cell integrity take place during the 4-hr exposure to N+Glu- followed by massive cell death 24 hr thereafter. Thus, we defined a culture system that can serve as a model to study mechanisms by which ischemic insult leads to suppression and eventually death of NPY neurons. Importantly, changes in NPY neurons can be integrated into the overall scheme of ischemic injury in the perinatal brain.

Neonatal seizures and neonatal epileptic syndromes

The neonatal period is defined as the first 28 days of life of a term infant; for premature infants the limit of this period is 44 completed weeks of the infant's conceptional age (CA)-defined as the chronological age plus gestational age (GA) at birth. The clinical and electroencephalographic (EEG) manifestations of seizures during this period are determined primarily by the development features of the immature brain at the time of seizure onset, but are also related to the type and diversity of etiologies and risk-factors for seizures neonates may face early in life. Neonatal seizures may be strikingly different from the clinical and electrical seizures of older children and adults. In addition, findings from basic science investigations suggest that immature animals are more likely to experience seizures in response to injury than more mature animals, although the developing brain is less susceptible to seizure-induced injury.