Neonatal stroke: a review of the current evidence on epidemiology, pathogenesis, diagnostics and therapeutic options

Arterial Presumed Perinatal Ischemic Stroke: A Mini Review and Case Report of Cognitive and Speech-Language Profiles in a 5-Year-Old Girl

Arterial presumed perinatal ischemic stroke is a type of perinatal stroke that emerges due to late or delayed diagnostics of perinatal or neonatal arterial ischemic stroke. It is usually recognized before one year of life due to hemiparesis. This injury may lead to cognitive, behavioral, or motor symptoms, and life-long neurodevelopmental disabilities. In this case report, we describe a five-year-old girl with a history of arterial presumed perinatal ischemic stroke in the left hemisphere, which adversely affected her cognitive and language outcomes. The girl's cognitive development has been uneven, ranging from below average to average, and she had specific language acquisition deficits in comprehension, vocabulary, morphology, use of complex syntax, and narrative structure. The obtained results point to the specificity of each child whose development is influenced not only by the timing of the brain lesion and the degree of damage, but also by the child's neurobiological capacity. In addition, we provide an updated review of the literature that includes information on epidemiology, risk factors, diagnostics, clinical manifestations, outcomes, and potential therapies. The present article highlights the importance of early intervention and systematic monitoring of children with perinatal stroke with the aim of improving the child's development.

Term-born infants with a perinatal stroke frequently had seizures and were prescribed anti-seizure medication at discharge

AIM

We investigated the prevalence of seizures in term-born infants with a perinatal stroke in Swedish neonatal wards, assessed the anti-seizure medication prescribed and determined the accuracy of diagnostic codes.

METHODS

This cross-sectional study used data from the Swedish Neonatal Quality Register. The cases were infants born at ≥37 weeks in 2009-2018 and admitted to a neonatal ward in Stockholm County with a stroke diagnosis, confirmed by their medical chart. The controls were all Swedish infants born during those years.

RESULTS

There were 76 infants with a confirmed perinatal stroke: 51 ischaemic and 25 haemorrhagic. Seizures were documented in 66/76 (87%) of infants with a stroke and 0.2% of the controls. Anti-seizure medication was administered to 64/66 (97%) infants with a stroke and seizures. In 60 cases, the drugs administered were specified, with phenobarbital used in 59/60 cases (98%). More than one drug was administered to 25/60 (42%) infants and 31/60 (52%) were discharged with anti-seizure medication. The positive predictive value for the stroke diagnostic codes was 80.5% (95% CI 76.5-84.5).

CONCLUSION

Seizures were common in infants with a perinatal stroke. More than one anti-seizure drug was often required and many infants were on anti-seizure medication at discharge, against Swedish recommendations.

Magnetic resonance venography to evaluate cerebral sinovenous thrombosis in infants receiving therapeutic hypothermia

BACKGROUND

The incidence of cerebral sinovenous thrombosis (CSVT) in infants receiving therapeutic hypothermia for neonatal encephalopathy remains controversial. The aim of this study was to identify if the routine use of magnetic resonance venography (MRV) in term-born infants receiving hypothermia is associated with diagnostic identification of CSVT.

METHODS

We performed a retrospective review of 291 infants who received therapeutic hypothermia from January 2014 to March 2020. Demographic and clinical data, as well as the incidence of CSVT, were compared between infants born before and after adding routine MRV to post-rewarming magnetic resonance imaging (MRI).

RESULTS

Before routine inclusion of MRV, 209 babies were cooled, and 25 (12%) underwent MRV. Only one baby (0.5%) was diagnosed with CSVT in that period, and it was detected by structural MRI, then confirmed with MRV. After the inclusion of routine MRV, 82 infants were cooled. Of these, 74 (90%) had MRV and none were diagnosed with CSVT.

CONCLUSION

CSVT is uncommon in our cohort of infants receiving therapeutic hypothermia for neonatal encephalopathy. Inclusion of routine MRV in the post-rewarming imaging protocol was not associated with increased detection of CSVT in this population.

IMPACT

Cerebral sinovenous thrombosis (CSVT) in infants with NE receiving TH may not be as common as previously indicated. The addition of MRV to routine post-rewarming imaging protocol did not lead to increased detection of CSVT in infants with NE. Asymmetry on MRV of the transverse sinus is a common anatomic variant. MRI alone may be sufficient in indicating the presence of CSVT.

Placental pathologic lesions associated with stroke in term neonates

OBJECTIVE

To determine the birth prevalence of perinatal stroke in term born infants at our high-volume delivery center and assess the frequency of both gross and histologic placental pathologies associated with perinatal stroke using the Amsterdam Placental Workshop Group Consensus Statement guidelines and definitions.

STUDY DESIGN

A single-center retrospective cohort study spanning 2010-2020.

RESULTS

There were 129,759 live births at Parkland Hospital during the study period and a total of 18 term born infants leading to a birth prevalence of 1 in 6,829 infants. Perinatal risk factors were found in all but one patient, and 74% presented with seizures. Pathologic placental examination was available in 56% of the cohort and only one patient had normal placental examination. Acute histologic chorioamnionitis was described in five placentas (50%) and an additional two had isolated umbilical and/or chorionic plate vasculitis with or without funisitis compared to a rate of 28% with acute inflammation in a Control group. Chronic inflammation in the form of villitis of unknown etiology was described in three of the acutely inflamed placentas and was high-grade in each of those while none of the placentas from our Control group showed evidence of any chronic lesion.

CONCLUSION

Both acute and chronic placental inflammation are common in perinatal stroke; placental examination should be considered an essential component to the diagnostic workup.

A pilot study of the General Movement Optimality Score detects early signs of motor disorder in neonates with arterial ischemic stroke

AIM

To explore whether the General Movement Optimality Score (GMOS) could help to identify asymmetric movement in infants with neonatal arterial ischemic stroke (NAIS) in the early stage.

METHOD

Twenty-seven infants with NAIS (16 males, 11 females) were enrolled. The general movement video was recorded approximately one month after birth. The GMOS focused separately on the neck and trunk and the upper and lower extremities. The differences between the ipsilesional and contralesional limbs were analyzed.

RESULTS

Eight infants who developed cerebral palsy (CP) had middle cerebral artery (MCA) infarction involving the main branch. By GMOS evaluation, the scores of the contralesional upper and/or lower limbs were lower than those of the ipsilesional side (p < 0.05). In the contralesional limbs, the CP group had a lower GMOS than the non-CP group. Distal rotatory components of the contralesional upper limbs and tremulous movement of the lower limbs showed significant differences.

INTERPRETATION

The GMOS could help to quantitatively find and assess the asymmetric movement of global and contralesional limbs. Distal rotatory movement of the upper limbs could be an early sign of abnormal motor function in infants with NAIS.

Neonatal Encephalopathy: Beyond Hypoxic-Ischemic Encephalopathy

Neonatal encephalopathy is a clinical syndrome of neurologic dysfunction that encompasses a broad spectrum of symptoms and severity, from mild irritability and feeding difficulties to coma and seizures. It is vital for providers to understand that the term "neonatal encephalopathy" is simply a description of the neonate's neurologic status that is agnostic to the underlying etiology. Unfortunately, hypoxic-ischemic encephalopathy (HIE) has become common vernacular to describe any neonate with encephalopathy, but this can be misleading. The term should not be used unless there is evidence of perinatal asphyxia as the primary cause of encephalopathy. HIE is a common cause of neonatal encephalopathy; the differential diagnosis also includes conditions with infectious, vascular, epileptic, genetic/congenital, metabolic, and toxic causes. Because neonatal encephalopathy is estimated to affect 2 to 6 per 1,000 term births, of which HIE accounts for approximately 1.5 per 1,000 term births, (1)(2)(3)(4)(5)(6) neonatologists and child neurologists should familiarize themselves with the evaluation, diagnosis, and treatment of the diverse causes of neonatal encephalopathy. This review begins by discussing HIE, but also helps practitioners extend the differential to consider the broad array of other causes of neonatal encephalopathy, emphasizing the epidemiology, neurologic presentations, diagnostics, imaging findings, and therapeutic strategies for each potential category.

Impact of stroke volume on motor outcome in neonatal arterial ischemic stroke

BACKGROUND AND OBJECTIVES

Neonatal arterial ischemic stroke (NAIS) can lead to long-term neurological consequences such as cerebral palsy (CP). The aim of this study was to evaluate the predictive value of acute diffusion-weighted imaging (DWI) for CP by analyzing stroke volume next to brain structure involvement.

METHODS

We included 37 term-born infants with NAIS prospectively registered in a nationwide pediatric stroke registry. DWI was performed between 0 and 8 days (mean 3 days) after stroke manifestation. Participants were neurologically assessed at the age of 2 years. We calculated the stroke volume (in mm³) and the ratio of the stroke volume to the volume of the entire brain (relative stroke volume). The predictive value of the relative stroke volume was analyzed and an optimal threshold for classification of children with high- and low-rates of CP was calculated. Predictive value of brain structure involvements and the prevalence of CP in combinations of different brain structures was also assessed.

RESULTS

Sixteen children (43.2%) developed CP. Relative stroke volume significantly predicted CP (p < .001). Its optimal threshold for division into high- and low-rate of CP was 3.3%. The basal ganglia (OR 8.3, 95% CI 1.2-60.0) and basis pontis (OR 18.5, 95% CI 1.8-194.8) were independently associated with CP.

CONCLUSION

In addition to determining the involvement of affected brain areas, the volumetric quantification of stroke volume allows accurate prediction of cerebral palsy in newborns with 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.

Vessel-specific quantification of neonatal cerebral venous oxygenation

PURPOSE

Noninvasive measurement of cerebral venous oxygenation (Y_v ) in neonates is important in the assessment of brain oxygen extraction and consumption, and may be useful in characterizing brain development and neonatal brain diseases. This study aims to develop a rapid method for vessel-specific measurement of Y_v in neonates.

METHODS

We developed a pulse sequence, named accelerated T₂ -relaxation-under-phase-contrast (aTRUPC), which consists of velocity-encoding phase-contrast module to isolate pure blood signal, flow-insensitive T₂ -preparation to quantify blood T₂ , and turbo-field-echo (TFE) scheme for rapid image acquisition, which is critical for neonatal MRI. A series of studies were conducted. First, the pulse sequence was optimized in terms of TFE factor, velocity encoding (VENC), and slice thickness for best sensitivity. Second, to account for the influence of TFE acquisition on T₂ quantification, simulation and experiments were conducted to establish the relationship between TFE-T₂ and standard T₂ . Finally, the complete aTRUPC sequence was applied on a group of healthy neonates and normative Y_v values were determined.

RESULTS

Optimal parameters of aTRUPC in neonates were found to be a TFE factor of 15, VENC of 5 cm/s, and slice thickness of 10 mm. The TFE-T₂ was on average 3.9% lower than standard T₂ . These two measures were strongly correlated (R² = 0.86); thus their difference can be accounted for by a correction equation, T_2,standard = 1.2002 × T_2,TFE - 10.6276. Neonatal Y_v values in veins draining cortical brain and those draining central brain were 64.8 ± 2.9% and 70.2 ± 3.3%, respectively, with a significant difference (P =.02).

CONCLUSION

The aTRUPC MRI has the potential to provide vessel-specific quantification of cerebral Y_v in neonates.

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.

Neurodevelopment After Perinatal Arterial Ischemic Stroke

BACKGROUND AND OBJECTIVES

Perinatal arterial ischemic stroke (PAIS) leads to cerebral palsy in ∼30% of affected children and has other neurologic sequelae. Authors of most outcome studies focus on middle cerebral artery (MCA) stroke without differentiating between site and extent of affected tissue. Our aim with this study was to report outcomes after different PAIS subtypes.

METHODS

Between 1990 and 2015, 188 term infants from 2 centers (London [n = 79] and Utrecht [n = 109]) had PAIS on their neonatal MRI. Scans were reevaluated to classify stroke territory and determine specific tissue involvement. At 18 to 93 (median 41.7) months, adverse neurodevelopmental outcomes were recorded as 1 or more of cerebral palsy, cognitive deficit, language delay, epilepsy, behavioral problems, or visual field defect.

RESULTS

The MCA territory was most often involved (90%), with posterior or anterior cerebral artery territory strokes occurring in 9% and 1%, respectively. Three infants died, and 24 had scans unavailable for reevaluation or were lost to follow-up. Of 161 infants seen, 54% had an adverse outcome. Outcomes were the same between centers. Main branch MCA stroke resulted in 100% adverse outcome, whereas other stroke subtypes had adverse outcomes in only 29% to 57%. The most important outcome predictors were involvement of the corticospinal tracts and basal ganglia.

CONCLUSIONS

Although neurodevelopmental outcome was adverse in at least 1 domain with main branch MCA stroke, in other PAIS subtypes outcome was favorable in 43% to 71% of children. Site and tissue involvement is most important in determining the outcome in PAIS.

Promoting neuroregeneration after perinatal arterial ischemic stroke: neurotrophic factors and mesenchymal stem cells

Newborns suffering from perinatal arterial ischemic stroke (PAIS) are at risk of neurodevelopmental problems. Current treatment options for PAIS are limited and mainly focus on supportive care, as presentation of PAIS is beyond the time window of current treatment strategies. Therefore, recent focus has shifted to interventions that stimulate regeneration of damaged brain tissue. From animal models, it is known that the brain increases its neurogenic capability after ischemic injury, by promoting neural cell proliferation and differentiation. However, neurogenesis is not maintained at the long term, which consequently impedes full repair leading to adverse consequences later in life. Boosting neuroregeneration of the newborn brain using treatment with neurotrophic factors and/or mesenchymal stem cells (MSCs) may be promising novel therapeutic strategies to improve neurological prospects and quality of life of infants with PAIS. This review focuses on effectiveness of neurotrophic growth factors, including erythropoietin, brain-derived neurotrophic factor, vascular endothelial growth factor, glial-derived neurotrophic factor, and MSC therapy, in both experimental neonatal stroke studies and first clinical trials for neonatal ischemic brain injury.

Pediatric brain repair from endogenous neural stem cells of the subventricular zone

There is great interest in the regenerative potential of the neural stem cells and progenitors that populate the germinal zones of the immature brain. Studies using animal models of pediatric brain injuries have provided a clearer understanding of the responses of these progenitors to injury. In this review, we have compared and contrasted the responses of the endogenous neural stem cells and progenitors of the subventricular zone in animal models of neonatal cerebral hypoxia-ischemia, neonatal stroke, congenital cardiac disease, and pediatric traumatic brain injury. We have reviewed the dynamic shifts that occur within this germinal zone with injury as well as changes in known signaling molecules that affect these progenitors. Importantly, we have summarized data on the extent to which cell replacement occurs in response to each of these injuries, opportunities available, and obstacles that will need to be overcome to improve neurological outcomes in survivors.

MR imaging for accurate prediction of outcome after perinatal arterial ischemic stroke: Sooner not necessarily better

BACKGROUND

Involvement of the corticospinal tracts after perinatal arterial ischemic stroke (PAIS) is strongly correlated with adverse motor outcome.

METHODS

Two full-term infants with PAIS, with two early MRI scans available, are reported.

RESULTS

Diffusion weighted imaging (DWI)-MRI, performed within 24 h following onset of seizures and repeated 48 h later, clearly showed restricted diffusion within the middle cerebral artery territory on both MRIs, but clear patterns of signal intensity changes in the descending corticospinal tracts on the second MRI only.

CONCLUSION

Since involvement of the corticospinal tracts is essential for prediction of motor outcome, we may need to reconsider optimal timing of MR imaging for prediction of neurodevelopmental outcome after PAIS.

Transient Middle Cerebral Artery Occlusion Model of Neonatal Stroke in P10 Rats

A number of animal models have been used to study hypoxic-ischemic injury, traumatic injury, global hypoxia, or permanent ischemia in both the immature and mature brain. Stroke occurs commonly in the perinatal period in humans, and transient ischemia-reperfusion is the most common form of stroke in neonates. The reperfusion phase is a critical component of injury progression, which occurs over a period of days to weeks, and of the endogenous response to injury. This postnatal day 10 (p10) rat model of transient middle cerebral artery occlusion (tMCAO) creates a unilateral, non-hemorrhagic focal ischemia-reperfusion injury that can be utilized to study the mechanisms of focal injury and repair in the full-term-equivalent brain. The injury pattern that is produced by tMCAO is consistent and highly reproducible and can be confirmed with MRI or histological analyses. The severity of injury can be manipulated through changes in occlusion time and other methods that will be discussed.

Brain oxygen saturation assessment in neonates using T2-prepared blood imaging of oxygen saturation and near-infrared spectroscopy

Although near-infrared spectroscopy is increasingly being used to monitor cerebral oxygenation in neonates, it has a limited penetration depth. The T₂-prepared Blood Imaging of Oxygen Saturation (T₂-BIOS) magnetic resonance sequence provides an oxygen saturation estimate on a voxel-by-voxel basis, without needing a respiratory calibration experiment. In 15 neonates, oxygen saturation measured by T₂-prepared blood imaging of oxygen saturation and near-infrared spectroscopy were compared. In addition, these measures were compared to cerebral blood flow and venous oxygen saturation in the sagittal sinus. A strong linear relation was found between the oxygen saturation measured by magnetic resonance imaging and the oxygen saturation measured by near-infrared spectroscopy ( R²= 0.64, p < 0.001). Strong linear correlations were found between near-infrared spectroscopy oxygen saturation, and magnetic resonance imaging measures of frontal cerebral blood flow, whole brain cerebral blood flow and venous oxygen saturation in the sagittal sinus ( R²= 0.71, 0.50, 0.65; p < 0.01). The oxygen saturation obtained by T₂-prepared blood imaging of oxygen saturation correlated with venous oxygen saturation in the sagittal sinus ( R²= 0.49, p = 0.023), but no significant correlations could be demonstrated with frontal and whole brain cerebral blood flow. These results suggest that measuring oxygen saturation by T₂-prepared blood imaging of oxygen saturation is feasible, even in neonates. Strong correlations between the various methods work as a cross validation for near-infrared spectroscopy and T₂-prepared blood imaging of oxygen saturation, confirming the validity of using of these techniques for determining cerebral oxygenation.

Abnormal neurodevelopmental outcomes are very likely in cases of bilateral neonatal arterial ischaemic stroke

AIM

Neonatal arterial ischaemic stroke (AIS) is an important cause of severe neurological disability. This study aimed to analyse the clinical manifestations and outcomes of AIS patients.

METHODS

We enrolled neonates with AIS admitted to Severance Children's Hospital and Gangnam Severance Hospital between 2008 and 2015. AIS was confirmed using magnetic resonance imaging (MRI). We retrospectively reviewed the clinical manifestations, MRI findings, electroencephalography (EEG) findings and neurodevelopmental outcomes.

RESULTS

The study comprised 29 neonates (18 boys). The mean follow-up period was 15.4 months (range 6-44 months), and the mean age at diagnosis was 8.1 days. Seizure was the most common symptom (66%). Bilateral involvement was more common than unilateral involvement (52%). The middle cerebral artery was the most commonly identified territory (79%). Abnormal EEG findings were noted in 93% of the cases. Neurodevelopment was normal in 11 (38%) patients, while cerebral palsy and delayed development were noted in eight (28%) and six (21%) patients, respectively. Patients with bilateral involvement were very likely to have abnormal neurodevelopmental outcomes.

CONCLUSION

Our study showed that abnormal neurodevelopmental outcomes were very likely after cases of neonatal AIS with bilateral involvement, and clinicians should consider early and more effective interventions in such cases.

Perinatal Arterial Ischemic Stroke Is Associated to Materno-Fetal Immune Activation and Intracranial Arteritis

The medium-size intra-cranial arteries arising from the carotid bifurcation are prone to perinatal arterial ischemic strokes (PAIS). PAIS’ physiopathology needs to be better understood to develop preventive and therapeutic interventions that are currently missing. We hypothesized that materno-fetal inflammation leads to a vasculitis affecting selectively the carotidian tree and promoting a focal thrombosis and subsequent stroke. Dams were injected with saline or lipopolysaccharide (LPS) from Escherichia coli. A prothrombotic stress was applied on LPS-exposed vs. saline (S)-exposed middle cerebral arteries (MCA). Immunolabeling detected the inflammatory markers of interest. In S-exposed newborn pups, a constitutive higher density of macrophages combined to higher expressions of tumor necrosis factor-α (TNF-α), and interleukin 1β (IL-1β) was observed within the wall of intra- vs. extra-cranial cervicocephalic arteries. LPS-induced maternal and placental inflammatory responses mediated by IL-1β, TNF-α and monocyte chemotactic protein 1 (MCP-1) were associated with: (i) increased density of pro-inflammatory macrophages (M1 phenotype); and (ii) pro-inflammatory orientation of the IL-1 system (IL-1β/IL-1 receptor antagonist (IL-1Ra) ratio) within the wall of LPS-, vs. S-exposed, intra-cranial arteries susceptible to PAIS. LPS plus photothrombosis, but not sole photothrombosis, triggered ischemic strokes and subsequent motor impairments. Based on these preclinical results, the combination of pro-thrombotic stress and selective intra-cranial arteritis arising from end gestational maternal immune activation seem to play a role in the pathophysiology of human PAIS.

Heparin for the treatment of thrombosis in neonates

BACKGROUND

Among pediatric patients, newborns are at highest risk of developing thromboembolism. Neonatal thromboembolic (TE) events may consist of both venous and arterial thromboses and often iatrogenic complications (eg, central catheterization). Treatment guidelines for pediatric patients with TE events most often are extrapolated from the literature regarding adults. Options for the management of neonatal TE events include expectant management; nitroglycerin ointment; thrombolytic therapy or anticoagulant therapy, or a combination of the two; and surgery. Since the 1990s, low molecular weight heparin (LMWH) has become the neonatal anticoagulant of choice. Reasons for its appeal include predictable dose response, no need for venous access, and limited monitoring requirements. The overall major complication rate is around 5%. Whether preterm infants are at increased risk is unclear. No data are available on the frequency of osteoporosis, heparin-induced thrombocytopenia (HIT), or other hypersensitivity reactions in children and neonates exposed to LMWH.

OBJECTIVES

To assess whether heparin treatment (both unfractionated heparin [UFH] and LMWH) reduces mortality and morbidity rates in preterm and term newborn infants with diagnosed thrombosis. The intervention is compared with placebo or no treatment. Also, to assess the safety of heparin therapy (both UFH and LMWH) for potential harms.Subgroup analyses were planned to examine gestational age, birth weight, mode of thrombus diagnosis, presence of a central line, positive family history for genetic disorders (thrombophilia, deficiency of protein S and protein C, methylenetetrahydrofolate reductase [MTHFR] mutation), route of heparin administration, type of heparin used, and location of thrombus (see "Subgroup analysis and investigation of heterogeneity").

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 4), MEDLINE via PubMed (1966 to May 9, 2016), Embase (1980 to May 9, 2016), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to May 9, 2016). We searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials.

SELECTION CRITERIA

Randomized, quasi-randomized, and cluster-randomized controlled trials comparing heparin versus placebo or no treatment in preterm and term neonates with a diagnosis of thrombosis.

DATA COLLECTION AND ANALYSIS

We used the standard methods of the Cochrane Neonatal Review Group. Two review authors independently assessed studies identified by the search strategy for inclusion.

MAIN RESULTS

Our search strategy yielded 1160 references. Two review authors independently assessed all references for inclusion. We found no completed studies and no ongoing trials for inclusion.

AUTHORS' CONCLUSIONS

We found no studies that met our inclusion criteria and no evidence from randomized controlled trials to recommend or refute the use of heparin for treatment of neonates with thrombosis.

Hypoxia and Neonatal Haemorrhagic Stroke: Experimental Study of Mechanisms

We studied the level of blood oxygen saturation (SpO2) in the brain in newborn rats in the pre- and post-stroke periods, as well as the changes in cerebral blood flow and beta-arrestin-1 as a marker of hypoxic stress. Our results show that mild hypoxia precedes the stroke development and is associated with venous relaxation and decrease blood outflow from the brain resulting in the elevation of synthesis of beta-arrestin-1 in the brain. The incidence of stroke is characterized by severe hypoxia, which is accompanied by the progression of pathological changes in cerebral veins and the high level of beta-arrestin-1.

Perinatal arterial ischemic stroke related to carotid artery occlusion

BACKGROUND

The aetiology of perinatal arterial ischemic stroke remains speculative. It is however widely accepted that the aetiology is multifactorial, involving various maternal, placental, foetal and neonatal risk factors. A resulting thromboembolic process is hypothesized and the placenta identified as the most plausible source. An arteriopathy, as observed in a significant proportion of childhood ischemic stroke, is thought to be rare.

METHODS

We report here five cases of perinatal stroke that differ from the vast majority by documented carotid occlusion, and add eleven other similar cases from the literature.

RESULTS

In the majority, an intraluminal thrombus of placental origin is the most probable hypothesis, while in the remaining ones, one can reasonably presume a direct vessel wall injury related to a traumatic delivery, yet generally unproven by imaging.

CONCLUSION

We hypothesize that most of these cases share similar pathophysiology with the more common perinatal arterial ischemic stroke but differ by a persistent identified thrombus in the carotid artery at the time of first imaging, leading to a more severe and extended ischemic damage responsible for an adverse neurological outcome.

The Stress and Vascular Catastrophes in Newborn Rats: Mechanisms Preceding and Accompanying the Brain Hemorrhages

In this study, we analyzed the time-depended scenario of stress response cascade preceding and accompanying brain hemorrhages in newborn rats using an interdisciplinary approach based on: a morphological analysis of brain tissues, coherent-domain optical technologies for visualization of the cerebral blood flow, monitoring of the cerebral oxygenation and the deformability of red blood cells (RBCs). Using a model of stress-induced brain hemorrhages (sound stress, 120 dB, 370 Hz), we studied changes in neonatal brain 2, 4, 6, 8 h after stress (the pre-hemorrhage, latent period) and 24 h after stress (the post-hemorrhage period). We found that latent period of brain hemorrhages is accompanied by gradual pathological changes in systemic, metabolic, and cellular levels of stress. The incidence of brain hemorrhages is characterized by a progression of these changes and the irreversible cell death in the brain areas involved in higher mental functions. These processes are realized via a time-depended reduction of cerebral venous blood flow and oxygenation that was accompanied by an increase in RBCs deformability. The significant depletion of the molecular layer of the prefrontal cortex and the pyramidal neurons, which are crucial for associative learning and attention, is developed as a consequence of homeostasis imbalance. Thus, stress-induced processes preceding and accompanying brain hemorrhages in neonatal period contribute to serious injuries of the brain blood circulation, cerebral metabolic activity and structural elements of cognitive function. These results are an informative platform for further studies of mechanisms underlying stress-induced brain hemorrhages during the first days of life that will improve the future generation's health.

T2-prepared velocity selective labelling: A novel idea for full-brain mapping of oxygen saturation

BACKGROUND AND AIM

Disturbances in cerebral oxygenation saturation (SO₂) have been linked to adverse outcome in adults, children, and neonates. In intensive care, the cerebral SO₂ is increasingly being monitored by Near-InfraRed Spectroscopy (NIRS). Unfortunately NIRS has a limited penetration depth. The "modified T₂-prepared Blood Imaging of Oxygen Saturation" (T₂-BIOS) MR sequence provides a step towards full brain SO₂ measurement.

MATERIALS AND METHODS

Tissue SO₂, and venous SO₂ (S_vO₂) were obtained simultaneously by T₂-BIOS during a respiratory challenge in ten healthy volunteers. These two measures were compared to SO₂ that was obtained by a single probe MR-compatible NIRS setup, and to cerebral blood flow and venous SO₂ that were obtained by arterial spin labelling and T₂-TRIR, respectively.

RESULTS

SO_2-T2-BIOS and SO_2-NIRS had a mean bias of -4.0% (95% CI -21.3% to 13.3%). S_vO_2-T2-BIOS correlated with SO_2-NIRS (R²=0.41, p=0.002) and S_vO_2-T2-TRIR (R²=0.87, p=0.002). In addition, SO_2-NIRS correlated with S_vO_2-T2-TRIR (R²=0.85, p=0.003) Frontal cerebral blood flow correlated with SO_2-T2-BIOS (R²=0.21, p=0.04), but was not significant in relation to SO_2-NIRS.

DISCUSSION/CONCLUSION

Full brain SO₂ assessment by any technique may help validating NIRS and may prove useful in guiding the clinical management of patient populations with cerebral injury following hypoxic-ischaemic events. The agreement between NIRS and T₂-BIOS provides confidence in measuring cerebral SO₂ by either technique. As it stands now, the T₂-BIOS represents a novel idea and future work will focus on improvements to make it a reliable tool for SO₂ assessment.

Delayed erythropoietin therapy improves histological and behavioral outcomes after transient neonatal stroke

BACKGROUND AND PURPOSE

Stroke is a major cause of neonatal morbidity, often with delayed diagnosis and with no accepted therapeutic options. The purpose of this study is to investigate the efficacy of delayed initiation of multiple dose erythropoietin (EPO) therapy in improving histological and behavioral outcomes after early transient ischemic stroke.

METHODS

32 postnatal day 10 (P10) Sprague-Dawley rats underwent sham surgery or transient middle cerebral artery occlusion (tMCAO) for 3h, resulting in injury involving the striatum and parieto-temporal cortex. EPO (1000U/kg per dose×3 doses) or vehicle was administered intraperitoneally starting one week after tMCAO (at P17, P20, and P23). At four weeks after tMCAO, sensorimotor function was assessed in these four groups (6 vehicle-sham, 6 EPO-sham, 10 vehicle-tMCAO and 10 EPO-tMCAO) with forepaw preference in cylinder rearing trials. Brains were then harvested for hemispheric volume and Western blot analysis.

RESULTS

EPO-tMCAO animals had significant improvement in forepaw symmetry in cylinder rearing trials compared to vehicle-tMCAO animals, and did not differ from sham animals. There was also significant preservation of hemispheric brain volume in EPO-tMCAO compared to vehicle-tMCAO animals. No differences in ongoing cell death at P17 or P24 were noted by spectrin cleavage in either EPO-tMCAO or vehicle-tMCAO groups.

CONCLUSIONS

These results suggest that delayed EPO therapy improves both behavioral and histological outcomes at one month following transient neonatal stroke, and may provide a late treatment alternative for early brain injury.

Cortical Sparing in Preterm Ischemic Arterial Stroke

Background and Purpose—

Residual injury after perinatal arterial ischemic stroke in the middle cerebral artery territory usually involves the loss of cortical gray matter and subcortical white matter. In this article, we describe a different pattern of residual injury after middle cerebral artery stroke in preterm-born infants, in which the cortex is spared.

Methods—

Magnetic resonance imaging scans of 40 infants (12 preterm and 28 full-term infants) with a large middle cerebral artery stroke were reviewed and correlated with outcome.

Results—

Complete sparing of the cortex with cavitation of the underlying white matter was observed in 3 preterm infants, and partial sparing was noted in another 4 late preterm–born infants. One full-term infant had partial cortical sparing, and all others showed no sparing. Overall, 86% developed a hemiplegia and 30% had a developmental quotient below 85, but this did not vary between the different types of cortical injury.

Conclusions—

The pattern of cortical injury after middle cerebral artery stroke changes with gestational age and may be related to maturational changes of the vascular system. Outcome did not vary between the different patterns of cortical injury.

Prediction of visual field defects in newborn infants with perinatal arterial ischemic stroke using early MRI and DTI-based tractography of the optic radiation

PURPOSE

Visual field (VF) defects are common sequelae of perinatal arterial ischemic stroke (PAIS). The aim of this study was to investigate the predictive value of magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) for VF defects following PAIS.

METHODS

Nineteen infants with unilateral PAIS, who underwent conventional MRI (T1/T2) and DTI at three months of age and a VF examination later in life (median age 3.2 yrs) were included. Conventional T1-weighted MRI was used to assess asymmetry of the optic radiation (OR). DTI-based tractography of the bilateral OR was performed, and the average fractional anisotropy (FA), axial (λ1), radial (λ23) and mean diffusivity (MD) were extracted. Asymmetry of the OR on MRI and DTI was used as a predictor of VF defects using receiver operating characteristic (ROC) analysis.

RESULTS

Of the 19 infants, nine had a normal VF, eight had a VF defect (six hemianopia and two quadrantanopia), and two had an inconclusive VF test. The presence or absence of a VF defect could be correctly predicted using conventional MRI assessment in the majority of the infants, with an area under the curve (AUC) of 0.90 (95% CI 0.66-0.99). Prediction based on DTI parameter asymmetry indices showed an AUC of 0.96 (95% CI 0.74-1.00), 0.78 (95% CI 0.52-0.94), 0.93 (95% CI 0.70-1.00) and 0.90 (95% CI 0.66-0.99) for FA, λ1, λ23 and MD, respectively.

CONCLUSIONS

VF defects following PAIS can be reliably predicted by assessment of asymmetry of the OR at three months on conventional MRI and DTI-based tractography with comparable predictive values. Conventional T1-weighted MRI can be used in clinical practice.

Perinatal thrombosis: implications for mothers and neonates

Stroke is more likely to occur in the perinatal period than any other time in childhood, and these events can lead to a lifetime of intellectual and motor disabilities, epilepsy, and behavioral challenges. This review describes the epidemiology and natural history of perinatal arterial ischemic stroke (PAIS) and cerebral sinovenous thrombosis (CSVT), risk factors for these complications, recent evidence regarding treatment strategies, and current gaps in knowledge. Existing evidence demonstrates the multifactorial etiology of symptomatic ischemic stroke in neonates, which includes a combination of maternal, delivery, and neonatal factors. The importance of inherited thrombophilia in the pathophysiology and long-term outcomes of perinatal stroke requires additional study. At this time, there is no evidence to support routine extensive thrombophilia screening outside of a research setting. Despite the frequency of perinatal stroke and its association with substantial morbidity, treatment strategies are currently limited, and prevention strategies are nonexistent. Anticoagulation is rarely indicated in PAIS, and more work needs to focus on neuroprotective prevention and alternate treatment strategies. Anticoagulation does appear to be safe in CSVT and may prevent thrombus progression but clinical equipoise remains, and clinical trials are needed to obtain evidence regarding short- and long-term efficacy outcomes.

Thrombosis in the Neonatal Intensive Care Unit

Neonates have the highest risk for pathologic thrombosis among pediatric patients. A combination of genetic and acquired risk factors significantly contributes to this risk, with the most important risk factor being the use of central venous catheters. Proper imaging is critical for confirming the diagnosis. Despite a significant number of these events being life- and limb-threatening, there is limited evidence on what the appropriate management strategy should be. Evaluation and treatment of any neonate with a clinically significant thrombosis should occur at a tertiary referral center that has proper support.

A Primer for Nurses on Perinatal/Neonatal Stroke

Perinatal or neonatal stroke is not uncommon, but diagnosis is often missed. Perinatal nurses are often the first health professionals in the position to observe the most typical symptom of stroke in a newborn, which is focal seizure. Etiology, symptoms and outcomes are reviewed and discussed through the context of the author's personal story.

Acute paraplegia in a preterm infant with cerebral sinovenous thrombosis

We report the case of a 1-month old, 28-week gestational age infant who presented with acute paraplegia after cardiopulmonary arrest. Later imaging confirms cerebral sinovenous thrombosis (CSVT) and a suspected infarction in the conus medullaris of the spinal cord. A prothrombotic state may explain the numerous areas of infarction visualized on neuroimaging. To our knowledge this is the first case report of acute and persistent paraplegia in an infant with CSVT and conus medullaris injury, which may be due to venous infarction of the spinal cord.

Cerebral sinovenous thrombosis in neonatal antiphospholipid syndrome: a new entity?

Neonatal antiphospholipid syndrome (neonatal APS) seems to be exceedingly rare, as the antiphospholipid antibodies (aPL) related thrombosis in the neonatal period. The pathogenesis of perinatal aPL related thrombosis may be explained both by the transplacental passage of the maternal antibodies and by the production of de novo antibodies by the neonate. However, few cases of neonatal APS are reported in the literature, especially regarding arterial thrombotic events. In particular, only two cases of neonatal aPL related isolated cerebral sinovenous thrombosis (CSVT) are described in the literature. Despite its frequency, CSVT results in significant mortality and morbidity, probably also due to the difficulty in early diagnosis and then in correct managing in the neonatal period. A diagnosis of neonatal APS should be considered in the evaluation of neonates with CSVT, as well as in any case of neonatal thrombosis, to correctly manage the affected neonates and counsel the mother for future pregnancies.

Effect of sex and age interactions on functional outcome after stroke

Stroke is one of the leading causes of death and disability worldwide. Experimental and clinical studies showed that sex and age play an important role in deciding the outcome after stroke. At younger ages, males were shown to have a higher risk for stroke than females. However, this trend reverses in older ages particularly when females reach menopause. Many preclinical studies indicate that steroid hormones modulate the age-dependent differential stroke outcome. In addition, patterns of cell death pathways activated following cerebral ischemia are distinct between males and females, but independent of steroid hormones. Recent studies also indicate that microRNAs play important roles in mediating sex-specific stroke outcome by regulating stroke-related genes. This review discusses the contribution of sex and age to outcome after stroke with particular emphasis on the experimental studies that examined the effects of steroid hormones, differential cell death pathways, and involvement of sex-specific microRNAs following cerebral ischemia. Current understanding of the role of thrombolytic agents in stroke therapy is also discussed.