Role of Perinatal Inflammation in Neonatal Arterial Ischemic Stroke

Cerebrospinal Fluid Composition of Infants with Ischemic Stroke

OBJECTIVE

 This study aimed to characterize the cerebrospinal fluid (CSF) of infants with stroke and compare those findings to the CSF of infants with bacterial meningitis and neither condition in the first 14 postnatal days.

STUDY DESIGN

 Cohort study of 30,092 infants who received a lumbar puncture in the first 14 postnatal days discharged from >400 neonatal intensive care units from 1997 to 2020. CSF parameters were compared between infants with stroke and bacterial meningitis using non-parametric hypothesis testing and quantile regression.

RESULTS

 Compared to infants with bacterial meningitis, infants with stroke had a significantly lower median protein concentration, higher median glucose concentration, higher median red blood cell count, and higher median monocyte count. Using quantile regression at the 75th percentile, infants with stroke had a significantly lower white blood cell count, segmented neutrophil count, and lymphocyte count than infants with bacterial meningitis.

CONCLUSION

 This study addresses the paucity of literature describing the CSF of infants with ischemic stroke. Knowledge of the differences in CSF parameters between infants with stroke and meningitis may allow for faster recognition and intervention before CSF culture results are available.

KEY POINTS

· Neonatal stroke is a serious and morbid event.. · Neonatal stroke and meningitis can present similarly.. · The CSF of neonatal stroke is poorly described..

Brain growth until adolescence after a neonatal focal injury: sex related differences beyond lesion effect

Introduction

Early focal brain injuries lead to long-term disabilities with frequent cognitive impairments, suggesting global dysfunction beyond the lesion. While plasticity of the immature brain promotes better learning, outcome variability across individuals is multifactorial. Males are more vulnerable to early injuries and neurodevelopmental disorders than females, but long-term sex differences in brain growth after an early focal lesion have not been described yet. With this MRI longitudinal morphometry study of brain development after a Neonatal Arterial Ischemic Stroke (NAIS), we searched for differences between males and females in the trajectories of ipsi- and contralesional gray matter growth in childhood and adolescence, while accounting for lesion characteristics.

Methods

We relied on a longitudinal cohort (AVCnn) of patients with unilateral NAIS who underwent clinical and MRI assessments at ages 7 and 16 were compared to age-matched controls. Non-lesioned volumes of gray matter (hemispheres, lobes, regions, deep structures, cerebellum) were extracted from segmented T1 MRI images at 7 (Patients: 23 M, 16 F; Controls: 17 M, 18 F) and 16 (Patients: 18 M, 11 F; Controls: 16 M, 15 F). These volumes were analyzed using a Linear Mixed Model accounting for age, sex, and lesion characteristics.

Results

Whole hemisphere volumes were reduced at both ages in patients compared to controls (gray matter volume: -16% in males, -10% in females). In ipsilesional hemisphere, cortical gray matter and thalamic volume losses (average -13%) mostly depended on lesion severity, suggesting diaschisis, with minimal effect of patient sex. In the contralesional hemisphere however, we consistently found sex differences in gray matter volumes, as only male volumes were smaller than in male controls (average -7.5%), mostly in territories mirroring the contralateral lesion. Females did not significantly deviate from the typical trajectories of female controls. Similar sex differences were found in both cerebellar hemispheres.

Discussion

These results suggest sex-dependent growth trajectories after an early brain lesion with a contralesional growth deficit in males only. The similarity of patterns at ages 7 and 16 suggests that puberty has little effect on these trajectories, and that most of the deviation in males occurs in early childhood, in line with the well-described perinatal vulnerability of the male brain, and with no compensation thereafter.

Risk factors of neonatal stroke from different origins: a systematic review and meta-analysis

Given the persistent ambiguity regarding the etiology of neonatal stroke across diverse origins, our objective was to conduct a comprehensive evaluation of both qualitative and quantitative risk factors. An exhaustive search of eight databases was executed to amass all pertinent observational studies concerning risk factors for neonatal stroke from various origins. Subsequent to independent screening, data extraction, and bias assessment by two researchers, a meta-analysis was conducted utilizing RevMan and Stata software. Nineteen studies, encompassing a total of 30 factors, were incorporated into this analysis. Beyond established risk factors, our investigation unveiled gestational diabetes (OR, 5.51; P < 0.00001), a history of infertility (OR, 2.44; P < 0.05), placenta previa (OR, 3.92; P = 0.02), postdates (OR, 2.07; P = 0.01), preterm labor (OR, 2.32; P < 0.00001), premature rupture of membranes (OR, 3.02; P = 0.007), a prolonged second stage of labor (OR, 3.94; P < 0.00001), and chorioamnionitis (OR, 4.35; P < 0.00001) as potential risk factors for neonatal cerebral arterial ischemic stroke. Additionally, postdates (OR, 4.31; P = 0.003), preterm labor (OR, 1.60; P < 0.00001), an abnormal CTG tracing (OR, 9.32; P < 0.0001), cesarean section (OR, 4.29; P = 0.0004), male gender (OR, 1.73; P = 0.02), and vaginal delivery (OR, 1.39; P < 0.00001) were associated with an elevated risk for neonatal hemorrhagic stroke.

CONCLUSIONS

This study provides a succinct overview and comparative analysis of maternal, perinatal, and additional risk factors associated with neonatal cerebral artery ischemic stroke and neonatal hemorrhagic stroke, furnishing critical insights for healthcare practitioners involved in the diagnosis and prevention of neonatal stroke. This research also broadens the conceptual framework for future investigations.

WHAT IS KNOWN

• Research indicates that prenatal, perinatal, and neonatal risk factors can elevate the risk of neonatal arterial ischemic stroke (NAIS). However, the risk factors for neonatal cerebral arterial ischemic stroke remain contentious, and those for neonatal hemorrhagic stroke (NHS) and neonatal cerebral venous sinus thrombosis (CVST) are still not well-defined.

WHAT IS NEW

• This study is the inaugural comprehensive review and meta-analysis encompassing 19 studies that explore maternal, perinatal, and various risk factors linked to neonatal stroke of differing etiologies. Notably, our analysis elucidates eight risk factors associated with NAIS: gestational diabetes mellitus, a history of infertility, placenta previa, postdates, preterm birth, premature rupture of membranes, a prolonged second stage of labor, and chorioamnionitis. Furthermore, we identify six risk factors correlated with NHS: postdates, preterm birth, an abnormal CTG, the method of delivery, male gender, and vaginal delivery. Additionally, our systematic review delineates risk factors associated with CVST.

Routine Echocardiography is not Required in Neonates with Arterial Ischemic Stroke

OBJECTIVE

Current guidelines suggest routine echocardiography (ECHO) in the acute phase to exclude a cardiac source for neonatal arterial ischemic stroke (NAIS). However, the commonly assumed embolic origin from a cardiac source for NAIS is challenged and the need for ECHO in NAIS remains questionable, especially during the era of standard fetal anomaly scanning. Our hypothesis is that any complex cardiac defects potentially causing NAIS would likely be detected during routine prenatal scans, thus possibly making routine postnatal ECHO redundant. This study aimed to determine the prevalence of significant cardiac risk factors and evaluate the necessity of routine postnatal ECHO in NAIS during the routine use of prenatal fetal sonography.

STUDY DESIGN

Retrospective review of 54 infants diagnosed with NAIS via brain magnetic resonance imaging who underwent an ECHO evaluation during the acute period to exclude potential cardiac origins for NAIS.

RESULTS

Postnatal ECHO revealed no intracardiac thrombus or vegetation, and only identified structural heart anomalies in three (5%) infants. Interestingly, these three cases had already been diagnosed with syndromic conditions or chromosomal malformations prenatally. In the remaining infants, postnatal ECHO was either normal or showed minor abnormalities unlikely to have contributed to the stroke. The detection rates of complex cardiac anomalies from prenatal scans and postnatal ECHO were statistically similar (p = 0.617).

CONCLUSION

The probability of ECHO to exclude cardiac sources for NAIS is so low that in the era of standard fetal anomaly scanning, routine postnatal ECHO may not be necessary for all NAIS infants, except when chromosomal malformations are detected.

KEY POINTS

· Guidelines recommend an acute phase ECHO to identify a cardiac source of NAIS.. · ECHO not effective at excluding NAIS's cardiac origin for infants with normal fetal scans.. · Routine postnatal ECHO is unnecessary in NAIS infants, except with genetic abnormalities..

Perinatal arterial ischemic stroke: how informative is the placenta?

Neuroplacentology is an expanding field of interest that addresses the placental influence on fetal and neonatal brain lesions and on further neurodevelopment. The objective of this study was to clarify the link between placental pathology and perinatal arterial ischemic stroke (PAIS). Prior publications have reported different types of perinatal stroke with diverse methodologies precluding firm conclusions. We report here the histological placental findings in a series of 16 neonates with radiologically confirmed PAIS. Findings were grouped into 3 categories of lesions: (1) inflammation, (2) placental and fetal hypoxic lesions, and (3) placentas with a high birthweight/placenta weight ratio. Matched control placentas were compared to the pathological placentas when feasible. The eight term singleton placentas were compared to a series of 20 placentas from a highly controlled amniotic membrane donation program; in three twin pregnancies, the placental portions from the affected twin and unaffected co-twin were compared. Slightly more than half (9/16, 56%) had histopathological features belonging to more than one category, a feature shared by the singleton control placentas (13/20, 65%). More severe and extensive lesions were however observed in the pathological placentas. One case occurring in the context of SARS-CoV-2 placentitis further expands the spectrum of COVID-related perinatal disease. Our study supports the assumption that PAIS can result from various combinations and interplay of maternal and fetal factors and confirms the value of placenta examination. Yet, placental findings must be interpreted with caution given their prevalence in well-designed controls.

Immune-Neurovascular Interactions in Experimental Perinatal and Childhood Arterial Ischemic Stroke

Emerging clinical and preclinical data have demonstrated that the pathophysiology of arterial ischemic stroke in the adult, neonates, and children share similar mechanisms that regulate brain damage but also have distinct molecular signatures and involved cellular pathways due to the maturational stage of the central nervous system and the immune system at the time of the insult. In this review, we discuss similarities and differences identified thus far in rodent models of 2 different diseases-neonatal (perinatal) and childhood arterial ischemic stroke. In particular, we review acquired knowledge of the role of resident and peripheral immune populations in modulating outcomes in models of perinatal and childhood arterial ischemic stroke and the most recent and relevant findings in relation to the immune-neurovascular crosstalk, and how the influence of inflammatory mediators is dependent on specific brain maturation stages. Finally, we discuss the current state of treatments geared toward age-appropriate therapies that signal via the immune-neurovascular interaction and consider sex differences to achieve successful translation.

Role of Microglial Modulation in Therapies for Perinatal Brain Injuries Leading to Neurodevelopmental Disorders

Neurodevelopmental disorders (NDDs) encompass various conditions stemming from changes during brain development, typically diagnosed early in life. Examples include autism spectrum disorder, intellectual disability, cerebral palsy, seizures, dyslexia, and attention deficit hyperactivity disorder. Many NDDs are linked to perinatal events like infections, oxygen disturbances, or insults in combination. This chapter outlines the causes and effects of perinatal brain injury as they relate to microglia, along with efforts to prevent or treat such damage. We primarily discuss therapies targeting microglia modulation, focusing on those either clinically used or in advanced development, often tested in large animal models such as sheep, non-human primates, and piglets-standard translational models in perinatal medicine. Additionally, it touches on experimental studies showcasing advancements in the field.

Long-term developmental condition following neonatal arterial ischemic stroke: A systematic review

BACKGROUND

Neonatal arterial ischemic stroke (NAIS) is the most frequent subtype of perinatal stroke. Its elusive pathophysiology, its abrupt and unexpected occurrence, and the uncertainty of the post-NAIS developmental condition may lead to parental emotional distress and psychological difficulties. The aim of this study was to summarize the current data on long-term developmental conditions following NAIS to support parental information given within the neonatal unit.

METHODS

This systematic review included clinical studies of term infants with NAIS, who had a developmental assessment at ≥5 years of age. Studies were identified from the Medline and Embase databases on June 1, 2022. The Joanna Briggs Institute (JBI) appraisal tool was used to assess the risk of bias. Results were synthesized using a narrative approach. The 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was followed to report this work.

RESULTS

Three cohort studies enrolling 205 children assessed from 5 to 7 years after NAIS were included. Most of the children presented long-term developmental conditions allowing them to be integrated into a regular school program, to participate in physical activities, and to have a good quality of life. Global intellectual deficiency and moderate-to-severe cerebral palsy occurred in less than 10% of the children.

CONCLUSION

Physicians should not overestimate the incidence of moderate-to-severe developmental outcome following NAIS when discussing the prognosis with parents. A parental information sheet about NAIS and its long-term developmental conditions is provided.

Perinatal Stroke in a Chinese Neonatal Center: Clinical Characteristics, Long-Term Outcomes, and Prognostic Factors

BACKGROUND

Neonatal stroke manifests atypically and can potentially result in significant neurological sequelae in affected infants. Studies on long-term neurodevelopmental outcomes and prognostic factors are limited. We aimed to assess the clinical characteristics, long-term outcomes, and prognostic factors of perinatal stroke.

METHODS

Patients diagnosed with perinatal stroke were enrolled from 2009 to 2018. Clinical data including general information, clinical manifestations, and risk factors were collected and compared. Follow-up was performed for at least two years. Statistical analysis was performed using the chi-square test, t tests, and logistic regression analysis.

RESULTS

Sixty-nine cases were identified with an incidence of one of 2049 live births (51 boys and 18 girls). Twenty-seven patients (39%) experienced perinatal ischemic stroke (PIS) and 42 (61%) perinatal hemorrhagic stroke (PHS). In 48 cases (69%) onset involved acute symptomatic stroke (21 ischemic strokes and 27 hemorrhagic strokes). Seizures within 12 to 72 hours (20 cases, 29%) were the most common presentations. Most (57%) perinatal arterial ischemic strokes focused on the left middle cerebral artery. About 43% of PHS was diagnosed with temporal lobe hemorrhage, and 40% of patients exhibited multiple lesions of cerebral parenchymal hemorrhage. There was no association between adverse prognosis after perinatal stroke and different risk factors. During follow-up, six patients (10%) were dead and 22 patients (35%) experienced adverse neurodevelopmental outcomes.

CONCLUSIONS

More infants exhibited hemorrhagic stroke than ischemic stroke. Among infants with asymptomatic perinatal stroke, PHS was more common. The first symptom of perinatal stroke within 12 to 72 hours after birth is convulsions, with the left middle cerebral artery and the temporal lobe being the most common lesion sites for ischemic and hemorrhagic strokes, respectively. PIS was more likely to achieve adverse outcomes.

Perinatal inflammation exposure and developmental outcomes 7 years after neonatal arterial ischaemic stroke

AIM

To test the association between perinatal inflammation exposure and Full-Scale IQ (FSIQ) score 7 years after neonatal arterial ischaemic stroke (NAIS).

METHOD

We conducted a cross-sectional ancillary study nested in a multicentric longitudinal French cohort of infants born at term with NAIS between November 2003 and October 2006. Seventy-three children were included (45 males, 28 females). The a priori defined primary outcome measure was the FSIQ score assessed with the Wechsler Intelligence Scale for Children, Fourth Edition at 7 years of age.

RESULTS

Seventeen (23%) of the included children were exposed to perinatal inflammation. Exposure to perinatal inflammation was independently associated with an increase of FSIQ score (coefficient 13.4, 95% confidence interval 1.3-25.4; p = 0.03). Children exposed to perinatal inflammation had a higher median cerebral volume, a lower median lesion volume, and less extensive lesion distributions compared to non-exposed children.

INTERPRETATION

We propose the existence of two NAIS categories: arteritis-associated NAIS in children exposed to perinatal inflammation and embolism-associated NAIS in children non-exposed to perinatal inflammation. Identifying these two NAIS categories would open the possibility for specific curative strategies: anti-inflammatory strategy in arteritis-associated NAIS and recanalization strategy in embolism-associated NAIS.

The Role of Infection and Inflammation in the Pathogenesis of Pediatric Arterial Ischemic Stroke

Infections play an important role in the pathogenesis of acute ischemic stroke (AIS) in neonates and children. In neonates, chorioamnionitis or intrauterine inflammation has been implicated as a common risk factor for AIS. In infants and children, recent investigations demonstrated that even minor childhood infections are associated with subsequent increased risk for AIS. Post-infectious inflammatory mechanisms following infections with herpesviruses may lead to focal cerebral arteriopathy (FCA), one of the most common causes of AIS in a previously healthy child. Other agents such as parvovirus B19, dengue virus, and SARS-CoV-2 have recently been implicated as other potential triggers. Infections are compelling treatable stroke risk factors, with available therapies for both pathogens and downstream inflammatory effects. However, infections are common in childhood, while stroke is uncommon. The ongoing VIPS II (Vascular effects of Infection in Pediatric Stroke) study aims to identify the array of pathogens that may lead to childhood AIS and whether either unusual strains or unusual combinations of pathogens explain this paradox. Immune modulation with corticosteroids for FCA is another active area of research, with European and U.S. trials launching soon. The results of these new pediatric stroke studies combined with findings emerging from the larger field of immune-mediated post-infectious diseases will likely lead to new approaches to the prevention and treatment of pediatric stroke. This review highlights recent developments from both clinical and animal model research enhancing our understanding of this relationship between infection, inflammation, and stroke in neonates and children.

Necroptosis Blockade Potentiates the Neuroprotective Effect of Hypothermia in Neonatal Hypoxic-Ischemic Encephalopathy

Neonatal encephalopathy (NE) caused by hypoxia-ischemia (HI) affects around 1 per 1000 term newborns and is the leading cause of acquired brain injury and neurodisability. Despite the use of hypothermia (HT) as a standard of care, the incidence of NE and its devastating outcomes remains a major issue. Ongoing research surrounding add-on neuroprotective strategies against NE is important as HT effects are limited, leaving 50% of treated patients with neurological sequelae. Little is known about the interaction between necroptotic blockade and HT in neonatal HI. Using a preclinical Lewis rat model of term human NE induced by HI, we showed a neuroprotective effect of Necrostatin-1 (Nec-1: a compound blocking necroptosis) in combination with HT. The beneficial effect of Nec-1 added to HT against NE injuries was observed at the mechanistic level on both pMLKL and TNF-α, and at the anatomical level on brain volume loss visualized by magnetic resonance imaging (MRI). HT alone showed no effect on activated necroptotic effectors and did not preserve the brain MRI volume. This study opens new avenues of research to understand better the specific cell death mechanisms of brain injuries as well as the potential use of new therapeutics targeting the necroptosis pathway.

Perinatal Ischemic Stroke: Etiology and Imaging

Perinatal ischemic stroke is a common cause of lifelong disability.

Neonatal Rat Glia Cultured in Physiological Normoxia for Modeling Neuropathological Conditions In Vitro

Cell culture conditions were proven to highly affect crucial biological processes like proliferation, differentiation, intercellular crosstalk, and senescence. Oxygen tension is one of the major factors influencing cell metabolism and thus, modulating cellular response to pathophysiological conditions. In this context, the presented study aimed at the development of a protocol for efficient culture of rat neonatal glial cells (microglia, astrocytes, and oligodendrocytes) in oxygen concentrations relevant to the nervous tissue. The protocol allows for obtaining three major cell populations, which play crucial roles in sustaining tissue homeostasis and are known to be activated in response to a wide spectrum of external stimuli. The cells are cultured in media without supplement addition to avoid potential modulation of cell processes. The application of active biomolecules for coating culturing surfaces might be useful for mirroring physiological cell interactions with extracellular matrix components. The cell fractions can be assembled as cocultures to further evaluate investigated mechanisms, intercellular crosstalk, or cell response to tested pharmacological compounds. Applying additional procedures, like transient oxygen and glucose deprivation, allows to mimic in vitro the selected pathophysiological conditions. The presented culture system for neonatal rat glial cells is a highly useful tool for in vitro modeling selected neuropathological conditions.

Suspected clinical chorioamnionitis with peak intrapartum temperature <380C: the prevalence of confirmed chorioamnionitis and short term neonatal outcome

Background

Chorioamnionitis (CA) affects up to 3.9% of all deliveries worldwide and is one of the leading causes of early-onset neonatal sepsis. Fever≥38⁰C is an essential criterion for the diagnosis of clinical CA. Obstetricians frequently take the maternal risk factors into consideration, and many mothers are treated as CA even with peak intrapartum temperature (PIT) between 37.6⁰C to 37.9⁰C if they have other clinical signs and risk factors.

Aim

To estimate the prevalence of confirmed chorioamnionitis and adverse neonatal outcomes among those mothers with PIT below 38⁰C.

Materials and methods

Retrospective chart review among mothers delivered at Al-Wakra Hospital, Qatar, between1^stJanuary2016 to 31^stDecember 2019 with a clinical suspicion of CA.

Results

Among 21,471 mothers, 442 were suspected of having CA (2.06%, 95% CI 1.88 to 2.26%). After exclusions, 415 were included in the study, 203(48.9%) mothers had PIT between 37.6-37.9⁰C. There was no significant difference in the rate of confirmed CA between the low (<38⁰C) and higher (≥38⁰C) temperature groups (25.4%Vs.31.3%, OR0.75, 95%CI0.46-1.25 , p.262). More patients in the low-temperature group received paracetamol for PIT between 37.6 to 37.9 ⁰C, while it was less frequently used for such milder elevation in higher temperature group (88.2%Vs.38.9%, OR11.69, 95% CI 6.46-2.15, p <.001).

Conclusion

The incidence of suspected clinical CA in our institution was within the international rates. Although nearly half of the mothers with suspected clinical CA had peak temperature below the recommended diagnostic criteria, the rate of confirmed CA and neonatal outcome was not significantly different from those with PIT≥38⁰C. Early antipyretic use might have affected further elevation of temperature.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03239-9.

The Incidence and Characteristics of Perinatal Stroke in Beijing: A Multicenter Study

Objective

To assess the incidence, risk factors, and clinical characteristics of perinatal stroke in Beijing.

Methods

This multicenter prospective study included all the live births from 17 representative maternal delivery hospitals in Beijing from March 1, 2019 to February 29, 2020. Neonates with a stroke were assigned to the study group. Clinical data, including general information, clinical manifestations, and risk factors, were collected. Up until 18 months after birth, neonates were routinely assessed according to the Ages and Stages Questionnaire (ASQ) and/or the Bayley scale. Statistical analysis was done using the chi-squared, t-tests, and logistic regression analysis using SPSS version 26.0.

Outcomes

In total, 27 cases were identified and the incidence of perinatal stroke in Beijing was 1/2,660 live births, including 1/5,985 for ischemic stroke and 1/4,788 for hemorrhagic stroke. Seventeen cases (62.96%) of acute symptomatic stroke and convulsions within 72 h (10 cases, 37.04%) were the most common presentations. Ten patients showed no neurological symptoms and were found to have had a stroke through routine cranial ultrasonography after being hospitalized for non-neurological diseases. The risk factors include primiparity, placental or uterine abruption/acute chorioamnionitis, intrauterine distress, asphyxia, and severe infection. In the study group, 11.1% (3/27) of patients had adverse neurodevelopmental outcomes. The patients in the study group had lower scores for the ASQ than those in the control group in the communication, gross, and fine motor dimensions.

Conclusion

The incidence of perinatal stroke in Beijing was consistent with that in other countries. Routine neuroimaging of infants with risk factors may enable identification of asymptomatic strokes in more patients. Patients who have suffered from a stroke may have neurological sequelae; therefore, early detection, treatment, and regular follow-ups are beneficial for improving their recovery outcomes.

Perinatal arterial ischemic stroke and periventricular venous infarction in infants with unilateral cerebral palsy

AIM

To explore clinical factors associated with perinatal arterial ischemic stroke (AIS) and periventricular venous infarction (PVI) in infants who develop unilateral cerebral palsy (CP).

METHOD

This was a case-control study. Data current to 2019 was extracted from the Canadian Cerebral Palsy Registry (CCPR). Cases were infants born at term with confirmed unilateral CP. Magnetic resonance images were stratified by expert review of reports as definitive perinatal stroke (AIS or PVI). Controls with common data elements were recruited from a population-based study in Alberta. Multivariable regression analyses were performed to estimate associations expressed as odds ratios with 95% confidence intervals.

RESULTS

Of 2093 cases from the CCPR, 662 had unilateral CP, of whom 299 (45%) had perinatal stroke: AIS 169 (57%) and PVI 130 (43%). Median age at diagnosis for AIS was 11.9 months (interquartile range: 6.2-25.7mo; range 0.17-104.1mo), and 58.6% were male. Median age at diagnosis for PVI was 25.3 months (interquartile range: 14.5-38mo, range 0.7-114.7mo) and 57.7% were male. Independent associations for both AIS and PVI on multivariable analysis were chorioamnionitis, illicit drug exposure, diabetes, gestational age, and maternal age. Variables associated with AIS alone were low Apgar score and prolonged rupture of membranes. Variables associated with PVI alone were small for gestational age and primigravida.

INTERPRETATION

Controlled analysis of disease-specific unilateral CP may offer unique perspectives on its pathophysiology. Acute intrapartum factors are mainly associated with AIS, while in utero factors are associated with PVI.

Development of the genomic inflammatory index (GII) to assess key maternal antecedents associated with placental inflammation

INTRODUCTION

Placental inflammation is associated with a variety of adverse health outcomes, including poor pregnancy outcomes as well as later in life health. The current clinical methodologies for evaluating placental histology for inflammation are limited in their sensitivity. The objective of this study was to develop a genomic inflammatory index (GII) that can be utilized as a biomarker to effectively quantify and evaluate placental inflammation.

METHODS

RNA-sequencing of n = 386 placentas from the Extremely Low Gestational Age Newborn (ELGAN) cohort was conducted. Transcriptional data for a biologically-targeted set of 14 genes, selected for their established role in pro-inflammatory signaling pathways, were aggregated to construct the GII. Multiple linear regression models were used to examine relationships between 47 perinatal factors and the GII.

RESULTS

The GII demonstrated a nine-fold difference across subjects and displayed positive trends with other indicators of placental inflammation. Significant differences in the GII were observed for race where women who self-identified as Black displayed higher levels of placental inflammation than those who self-identified as White women (p < 0.001). Additionally, married Black women showed reduced placental inflammation compared to those who were unmarried (beta value: 0.828, p-value: 0.032). Placentas from women who were treated with steroids during the delivery of the infant displayed higher GII levels than those who were not (p = 0.023).

DISCUSSION

Overall, the GII demonstrated an association between various perinatal factors and placental inflammation. It is anticipated that the GII will provide a novel genomics tool for quantifying placental inflammation, allowing for further investigation of causes, and ultimately the prevention, of inflammation in the placenta.

Abnormal development of cerebral arteries and veins in offspring of experimentally preeclamptic rats: Potential role in perinatal stroke

Preeclampsia, a hypertensive disorder of pregnancy, complicates up to 10 % of all pregnancies and increases the risk for perinatal stroke in offspring. The mechanism of this increase is unknown, but may involve vascular dysfunction. The goal of this study was to evaluate the effect of experimental preeclampsia (ePE) on cerebrovascular function in offspring to eludciate a possible mechanism for this association. Dams were fed a high cholesterol diet beginning on day 7 of gestation to induce experimental preeclampsia. Middle cerebral arteries (MCA) and the Vein of Galen (VoG) were isolated from pups from ePE dams and compared to pups from normal pregnant (NP) dams at postnatal days 16, 23, and 30 and studied pressurized in an arteriograph chamber. Markers of inflammation and oxidative stress were measured in serum. Our results suggest altered structure and function in both MCA and VoG of ePE pups. We also found evidence of systemic inflammation and oxidative stress in ePE pups. These findings provide a potential link between preeclampsia and the occurrence or severity of perinatal stroke.

Clinical Diversity of Cerebral Sinovenous Thrombosis and Arterial Ischaemic Stroke in the Neonate: A Surveillance Study

INTRODUCTION

Incidence, risk factors, clinical presentation, onset of symptoms, and age at diagnosis differ between neonatal arterial ischaemic stroke (AIS) and cerebral sinovenous thrombosis (CSVT). A more accurate and earlier discrimination of these two entities can be of eminent importance.

METHODS

Active surveillance for AIS and CSVT was performed in 345 German paediatric hospitals. Only MRI confirmed cases were included in our analysis. Patients with AIS were compared to CSVT cases with regard to age at diagnosis, pattern of clinical symptoms, and case characteristics.

RESULTS

Data on 144 AIS and 51 CSVT neonatal cases were collected from 2015 to 2017. The frequency of reported AIS cases was 2.8 [95% CI 2.1; 3.9] times higher compared to reported CSVT cases. CSVT patients were more likely to be born premature (CSVT 14/48, 29.2%; AIS 19/140, 13.2%; p = 0.02) and to have signs of perinatal acidosis (30.2% CSVT vs. 13.5% AIS; p = 0.01). Generalized seizures and lethargy were more likely to occur in infants with CSVT (p < 0.0001). Age at onset of symptoms and at time of diagnosis were shifted to older ages in CSVT (p < 0.0001).

DISCUSSION/CONCLUSION

In the neonatal period, AIS is about three times more common than CSVT. A higher proportion of critically ill infants in CSVT and a later onset of symptoms may indicate that perinatal and postnatal complications are more important for CSVT than for AIS.

Pathophysiology and Treatment of Stroke: Present Status and Future Perspectives

Stroke is the second leading cause of death and a major contributor to disability worldwide. The prevalence of stroke is highest in developing countries, with ischemic stroke being the most common type. Considerable progress has been made in our understanding of the pathophysiology of stroke and the underlying mechanisms leading to ischemic insult. Stroke therapy primarily focuses on restoring blood flow to the brain and treating stroke-induced neurological damage. Lack of success in recent clinical trials has led to significant refinement of animal models, focus-driven study design and use of new technologies in stroke research. Simultaneously, despite progress in stroke management, post-stroke care exerts a substantial impact on families, the healthcare system and the economy. Improvements in pre-clinical and clinical care are likely to underpin successful stroke treatment, recovery, rehabilitation and prevention. In this review, we focus on the pathophysiology of stroke, major advances in the identification of therapeutic targets and recent trends in stroke research.

The Role of the Placenta in Perinatal Stroke: A Systematic Review

CONTEXT

Placental pathology may be an important missing link in the causal pathway of perinatal stroke. The study aim was to systematically review the literature regarding the role of the placenta in perinatal stroke. MEDLINE, Embase, Scopus, and Web of Science electronic databases were searched from 2000 to 2019. Studies were selected based on predefined criteria. To enable comparisons, placental abnormalities were coded using Redline's classification.

RESULTS

Ten studies met the inclusion criteria. Less than a quarter of stroke cases had placental pathology reported. Placental abnormalities were more common among children with perinatal stroke than in the control group. The most frequent placental abnormality was Redline's category 2 (thrombo-inflammatory process).

CONCLUSIONS

Placental abnormalities appear to be associated with perinatal stroke, supporting additional indirect evidence and biological plausibility of a causative role. However, the results should be interpreted cautiously considering the low frequency of placental examination and lack of uniformity in placental pathology reporting.

CLINICAL TRIAL REGISTRATION

PROSPERO Registration no: CRD42017081256.

Perinatal inflammation is associated with social and motor impairments in preterm children without severe neonatal brain injury

OBJECTIVE

To test the association between exposure to perinatal inflammation - i.e. clinical chorioamnionitis or early-onset neonatal infection - in preterm children without severe neonatal brain injury and neurodevelopmental outcome at 30 months of corrected age (CA).

DESIGN

Cross-sectional study from a French regional cohort of clinical follow-up (SEVE Network).

PATIENTS

One hundred sixty-four surviving neonates without severe brain injury - namely, grade III and IV cerebral hemorrhage and cystic periventricular leukomalacia - and without late-onset neonatal inflammation exposure - namely, late-onset neonatal infection and necrotizing enterocolitis -, born at less than 33 weeks of gestational age from November 2011 to June 2015 and enrolled in the SEVE Network.

MAIN OUTCOME MEASURE

Global developmental quotient (DQ) score of the revised Brunet-Lézine scale and its four indices measured by the same neuropsychologist at 30 months of CA.

RESULTS

After multivariate analysis, exposure to perinatal inflammation was not found significantly associated with a modification of the global DQ score (coefficient -1.7, 95% CI -4.8 to 1.3; p = 0.26). Exposure to perinatal inflammation was associated with a decrease of the gross motor function DQ score (coefficient -6.0, 95% CI -9.9 to -2.1; p < 0.01) and a decrease of the sociability DQ score (coefficient -5.1, 95% CI -9.2 to -0.9; p = 0.02). Language and visuospatial coordination DQ scores were not affected by exposure to perinatal inflammation.

CONCLUSION

Exposure to perinatal inflammation in preterm children without severe neonatal brain injury is independently associated with decreased motor and social abilities at 30 months of CA.

Risk factors for perinatal arterial ischaemic stroke: a large case-control study

AIM

To identify maternal, obstetric, and neonatal risk factors related to perinatal arterial ischaemic stroke (PAIS) diagnosed within 28 days after birth and to understand the underlying pathophysiology.

METHOD

For case and control ascertainment, we used active surveillance in 345 paediatric hospitals and a population-based perinatal database for quality assurance of hospital care. We analysed complete cases of PAIS using logistic regression. Multivariate analysis was guided by a directed acyclic graph.

RESULTS

After exclusion of records with missing data, we analysed 134 individuals with PAIS and 576 comparison individuals. In univariate analysis, male sex, preterm birth (<37wks gestational age), small for gestational age (SGA), low umbilical artery pH (<7.1), low 5-minute-Apgar score (<7), multiple pregnancies, hypoxia, intubation/mask ventilation, nulliparity, Caesarean section, vaginal-operative delivery, chorioamnionitis, and oligohydramnios were associated with an increased risk. Mutual adjustment yielded male sex (odds ratio [OR] 1.81; 95% confidence interval [CI] 1.20-2.73), multiple birth (OR 3.22; 95% CI 1.21-8.58), chorioamnionitis (OR 9.89; 95% CI 2.88-33.94), preterm birth (OR 1.86; 95% CI 1.01-3.43), and SGA (OR 3.05; 95% CI 1.76-5.28) as independent risk factors.

INTERPRETATION

We confirmed the increased risk in males and the role of chorioamnionitis and SGA for PAIS, pointing to the importance of inflammatory processes and fetal-placental insufficiency. Multiple birth and preterm birth were additional risk factors.

WHAT THIS PAPER ADDS

Chorioamnionitis and small for gestational age (SGA) precede perinatal arterial ischaemic stroke (PAIS). Chorioamnionitis and SGA are independent risk factors for PAIS. Inflammatory processes and fetal-placental insufficiency are the likely underlying mechanisms. Multiple birth and preterm birth are additional risk factors.

Benefits of hypothermia in neonatal arterial ischemic strokes: A preclinical study

BACKGROUND

There is currently no targeted treatment available for neonatal arterial ischemic strokes (NAIS). Epidemiological studies demonstrated that perinatal infection/inflammation, peripartum hypoxia, and occlusion of the internal carotid tree are the main determinants of NAIS. The well-established benefit of therapeutic hypothermia (HT) in neonatal encephalopathy due to diffuse hypoxia-ischemia provides a rationale for the potential use of HT as a neuroprotective strategy in NAIS.

METHODS

We used a rat model to reproduce the most prevalent human physiopathological scenario of NAIS. The neuroprotective effect of HT was measured by morphometric magnetic resonance imaging, [¹⁸ F] fluorodeoxyglucose (FDG) metabolic activity by positron emission tomography/computed tomography, and behavioral tests.

RESULTS

HT (a) prevented the occurrence of 44% of NAIS, (b) reduced the volume of strokes by 37%, (c) enhanced [¹⁸ F] FDG metabolic activity within the territory of the occluded carotid artery, and (d) improved motor behavior. Both morphometric and metabolic techniques showed consistently that HT provided a neuroprotective effect located in the motor cortex, hippocampus, and caudate-putamen.

CONCLUSION

Through combining anatomical, metabolic imaging, and behavioral studies, our study provides evidence of neuroprotective effects of HT in NAIS. These results are potentially translational to human NAIS.

Perinatal Stroke

Perinatal strokes are a diverse but specific group of focal cerebrovascular injuries that occur early in brain development and affect an estimated 5 million people worldwide. The objective of this review is to describe the epidemiology, clinical presentations, pathophysiology, outcomes, and management for the 6 subtypes of perinatal stroke. Some perinatal strokes are symptomatic in the first days of life, typically with seizures, including neonatal arterial ischemic stroke, neonatal hemorrhagic stroke, and cerebral sinovenous thrombosis. The remaining subtypes present in the first year of life or later, usually with motor asymmetry and include arterial presumed perinatal ischemic stroke, presumed perinatal hemorrhagic stroke, and in utero periventricular venous infarction. The consequences of these injuries include cerebral palsy, epilepsy, and cognitive and behavioral challenges, in addition to the psychosocial impact on families. While there have been significant advances in understanding mechanisms of both injury and recovery, there is still a great deal to learn regarding causation and the optimization of outcomes.

Perinatal carotid artery ischemic stroke: Report of two cases

The mechanisms of perinatal stroke are poorly understood but preclinical studies point to the crucial role of perinatal inflammation. Carotid artery occlusion represents a very rare and severe cause of perinatal stroke. We describe two cases diagnosed with extensive ischemic stroke due to carotid artery occlusion. In both cases, we demonstrated placental vasculopathy. High levels of C-reactive protein in mother and/or neonates suggested inflammatory mechanism as a potential trigger. Both cases underwent hypothermic treatment without complications because of initial diagnosis of perinatal asphyxia. The prognosis at the time of the last follow up was severe including cerebral palsy, epilepsy and cognitive impairment. Our cases contribute to the actual debate on pathogenic mechanisms and treatment options for this rare condition.

The emerging role of immunothrombosis in paediatric conditions

BACKGROUND

Immunothrombosis is a physiological process based on the release of neutrophil extracellular traps (NETs) to immobilise, contain and kill bacteria. This is an innate immune response in which the local activation of blood coagulation exerts the critical protective function during microbial infection. In recent years, there has been much interest in the adult literature about the key role of immunothrombosis in pathologic states including thrombosis, cancer, sepsis and trauma. Currently, little research has been done into its role in paediatric conditions.

METHODS

We conducted a literature search of the National Library of Medicine (MEDLINE/PubMed) from the years 2000 to May 2018 and qualitatively identified 24 relevant papers. References of articles included for full-text review were checked for relevant publications.

RESULTS

Our aim is to summarise the most relevant evidences regarding an excessive production or defective removal of NETs in paediatric conditions. In particular, we have divided the role of immunothrombosis into acute (sepsis, necrotising enterocolitis, otitis media, neonatal arterial ischaemic stroke, haemolytic anaemic diseases) and chronic (systemic lupus erythematous, type 1 diabetes mellitus, respiratory diseases, graft-versus-host disease) conditions to find important similarities in their pathophysiology.

CONCLUSION

The field of immunothrombosis in paediatric conditions is still in its infancy. We have presented multiple pathways of NET-induced disease together with possible areas of future research and treatments.

Perinatal stroke syndromes: Similarities and diversities in aetiology, outcome and management

With a birth-prevalence of 37-67/100,000 (mostly term-born), perinatal stroke encompasses distinct disease-states with diverse causality, mechanism, time of onset, mode of presentation and outcome. Neonatal primary haemorrhagic stroke and ischemic events (also divided into neonatal arterial ischemic stroke and neonatal cerebral sinus venous thrombosis) that manifest soon after birth are distinguished from presumed perinatal - ischemic or haemorrhagic - stroke. Signs of the latter become apparent only beyond the neonatal period, most often with motor asymmetry or milestones delay, and occasionally with seizures. Acute or remote MRI defines the type of stroke and is useful for prognosis. Acute care relies on homeostatic maintenance. Seizures are often self-limited and anticonvulsant agents might be discontinued before discharge. Prolonged anticoagulation for a few weeks is an option in some cases of sinovenous thrombosis. Although the risk of severe impairment is low, many children develop mild to moderate multimodal developmental issues that require a multidisciplinary approach.

Rodent Models of Developmental Ischemic Stroke for Translational Research: Strengths and Weaknesses

Cerebral ischemia can occur at any stage in life, but clinical consequences greatly differ depending on the developmental stage of the affected brain structures. Timing of the lesion occurrence seems to be critical, as it strongly interferes with neuronal circuit development and determines the way spontaneous plasticity takes place. Translational stroke research requires the use of animal models as they represent a reliable tool to understand the pathogenic mechanisms underlying the generation, progression, and pathological consequences of a stroke. Moreover, in vivo experiments are instrumental to investigate new therapeutic strategies and the best temporal window of intervention. Differently from adults, very few models of the human developmental stroke have been characterized, and most of them have been established in rodents. The models currently used provide a better understanding of the molecular factors involved in the effects of ischemia; however, they still hold many limitations due to matching developmental stages across different species and the complexity of the human disorder that hardly can be described by segregated variables. In this review, we summarize the key factors contributing to neonatal brain vulnerability to ischemic strokes and we provide an overview of the advantages and limitations of the currently available models to recapitulate different aspects of the human developmental stroke.

Bedside neurophysiological tests can identify neonates with stroke leading to cerebral palsy

OBJECTIVE

The unspecific symptoms of neonatal stroke still challenge its bedside diagnosis. We studied the accuracy of routine electroencephalography (EEG) and simultaneously recorded somatosensory evoked potentials (EEG-SEP) for diagnosis and outcome prediction of neonatal stroke.

METHODS

We evaluated EEG and EEG-SEPs from a hospital cohort of 174 near-term neonates with suspected seizures or encephalopathy, 32 of whom were diagnosed with acute ischemic or hemorrhagic stroke in MRI. EEG was scored for background activity and seizures. SEPs were classified as present or absent. Developmental outcome of stroke survivors was evaluated from medical records at 8- to 18-months age.

RESULTS

The combination of continuous EEG and uni- or bilaterally absent SEP (n = 10) was exclusively seen in neonates with a middle cerebral artery (MCA) stroke (specificity 100%). Moreover, 80% of the neonates with this finding developed with cerebral palsy. Bilaterally present SEPs did not exclude stroke, but predicted favorable neuromotor outcome in stroke survivors (positive predictive value 95%).

CONCLUSIONS

Absent SEP combined with continuous EEG background in near-term neonates indicates an MCA stroke and a high risk for cerebral palsy.

SIGNIFICANCE

EEG-SEP offers a bedside method for diagnostic screening and a reliable prediction of neuromotor outcome in neonates suspected of having a stroke.

Perinatal arterial ischemic stroke

Perinatal arterial ischemic stroke is a relatively common and serious neurologic disorder that can affect the fetus, the preterm, and the term-born infant. It carries significant long-term disabilities. Herein we describe the current understanding of its etiology, pathophysiology and classification, different presentations, and optimal early management. We discuss the role of different brain imaging modalities in defining the extent of lesions and the impact this has on the prediction of outcomes. In recent years there has been progress in treatments, making early diagnosis and the understanding of likely morbidities imperative. An overview is given of the range of possible outcomes and optimal approaches to follow-up and support for the child and their family in the light of present knowledge.

A Model of Perinatal Ischemic Stroke in the Rat: 20 Years Already and What Lessons?

Neonatal hypoxia-ischemia (HI) and ischemia are a common cause of neonatal brain injury resulting in cerebral palsy with subsequent learning disabilities and epilepsy. Recent data suggest a higher incidence of focal ischemia-reperfusion located in the middle cerebral artery (MCA) territory in near-term and newborn babies. Pre-clinical studies in the field of cerebral palsy research used, and still today, the classical HI model in the P7 rat originally described by Rice et al. (1). At the end of the 90s, we designed a new model of focal ischemia in the P7 rat to explore the short and long-term pathophysiology of neonatal arterial ischemic stroke, particularly the phenomenon of reperfusion injury and its sequelae (reported in 1998). Cerebral blood-flow and cell death/damage correlates have been fully characterized. Pharmacologic manipulations have been applied to the model to test therapeutic targets. The model has proven useful for the study of seizure occurrence, a clinical hallmark for neonatal ischemia in babies. Main pre-clinical findings obtained within these 20 last years are discussed associated to clinical pattern of neonatal brain damage.

Perinatal stroke: mechanisms, management, and outcomes of early cerebrovascular brain injury

Perinatal stroke encompasses a heterogeneous group of focal neurological injuries early in brain development that probably affects more than 5 million people worldwide. Many such injuries are symptomatic in the first days of life, including neonatal arterial ischaemic stroke, cerebral sinovenous thrombosis, and neonatal haemorrhagic stroke. The remaining focal neurological injuries usually present later in the first year with motor asymmetry, such as arterial presumed perinatal ischaemic stroke, periventricular venous infarction, and presumed perinatal haemorrhagic stroke. The numerous sequelae of these injuries include hemiparesis (cerebral palsy), epilepsy, and cognitive, language, and behavioural challenges. In this Review we summarise each perinatal stroke disease, examining the epidemiology, pathophysiology, acute management, and outcomes, including the effect on parents and families, and emerging therapies to mitigate these lifelong morbidities.

Cytokine production pattern of T lymphocytes in neonatal arterial ischemic stroke during the first month of life-a case study

Background

The perinatal period carries the highest risk for stroke in childhood; however, the pathophysiology is poorly understood and preventive, prognostic, and therapeutic strategies are not available. A new pathophysiological model describes the development of neonatal arterial ischemic stroke (NAIS) as the combined result of prenatal inflammation and hypoxic–ischemic insult. Neuroinflammation and a systemic inflammatory response are also important features of NAIS. Identifying key players of the inflammatory system is in the limelight of current research.

Case presentation

We present four NAIS cases, in whom detailed analysis of intracellular and plasma cytokine levels are available from the first month of life. All neonates were admitted with the initial diagnosis of hypoxic ischemic encephalopathy (HIE); however, early MRI examination revealed NAIS. Blood samples were collected between 3 and 6 h of life, at 24 h, 72 h, 1 week, and 1 month of life. Peripheral blood mononuclear cells were assessed with flow cytometry and plasma cytokine levels were measured. Pooled data from the cohort of four NAIS patients were compared to infants with HIE.

At 6 and 72 h of age, the prevalence of IL10+ CD8+ lymphocytes remained lower in NAIS. At 6 h, CD8+ lymphocytes in NAIS produced more IL-17. At 72 h, CD8+ cells produced more IL-6 in severe HIE than in NAIS, but IL-6 production remained elevated in CD8 cells at 1 month in NAIS, while it decreased in HIE. At 1 week, the prevalence of TGF-β + lymphocytes prone to enter the CNS was elevated in NAIS. On the other hand, by 1 month of age, the prevalence of TGF-β + CD4+ lymphocytes decreased in NAIS compared to HIE. At 72 h, we found elevated plasma levels of IL-5, MCP-1, and IL-17 in NAIS. By 1 month, plasma levels of IL-4, IL-12, and IL-17 decreased in NAIS but remained elevated in HIE.

Conclusions

Differences in the cytokine network are present between NAIS and HIE. CD8 lymphocytes appear to shift towards the pro-inflammatory direction in NAIS. The inflammatory response appears to be more pronounced at 72 h in NAIS but decreases faster, reaching lower plasma levels of inflammatory markers at 1 month.