Neurodevelopment After Perinatal Arterial Ischemic Stroke

Individualized Neuroprognostication in Neonates With Hypoxic-Ischemic Encephalopathy Treated With Hypothermia

Background and Objectives

To determine whether post-rewarming brain MRI enables individualized domain-specific prediction of neurodevelopmental outcomes at 2 years of age in infants treated with hypothermia for hypoxic-ischemic brain injury.

Methods

We conducted a retrospective multicenter study of infants with moderate-to-severe hypoxic-ischemic encephalopathy (HIE) treated with hypothermia. Brain MRI abnormalities and the prediction of domain-specific 2-year neurodevelopmental outcomes were scored independently by 2 investigators after which consensus was reached for both imaging findings and outcome prediction. Neuroimaging patterns were categorized as normal, white matter (WM)/watershed-predominant, deep gray matter (DGM)-predominant, and near-total injury. Outcomes were predicted separately for mortality, cerebral palsy (CP) type and severity, cognitive delay, epilepsy, cerebral visual impairment (CVI), and feeding difficulties; these outcomes were predicted as highly unlikely, possible, probable, or highly likely.

Results

Of the 152 study infants, 27 (18%) died. The neurodevelopmental outcome at 2 years was available in all 125 survivors. CP was seen in 21 of 125 surviving infants (17%). No infants in the highly unlikely category developed CP while 90% in the highly likely category did. When CP was predicted as possible, 40% developed CP; all were mild and ambulatory. When CP was predicted as probable, 67% developed CP of whom 40% were severe and nonambulatory. Cognitive scores were available in 104 of 125 infants (83%). Cognitive delay was seen in 23 of 104 infants (22%) (15% mild and 7% severe). When cognitive delay was predicted as highly unlikely, 92% did not develop cognitive delay and the delay was mild in those who did. When cognitive delay was considered highly likely, this developed in 100%. When epilepsy, CVI, and feeding problems were predicted as highly unlikely, 98% did not develop epilepsy; for CVI and feeding problems, this was 100% and 97%, respectively. In 27 of 152 infants (18%), the investigators reached consensus that the overall injury was severe enough to consider redirection of care; 21 of 27 infants (78%) died. Of the survivors, 5 infants developed severe CP and 1 had a mild dyskinetic CP with swallowing problems and CVI.

Discussion

Individualized domain-specific categorical neuroprognostication mainly based on brain MRI is feasible, reliable, and highly accurate in infants with HIE.

EEG alpha band functional brain network correlates of cognitive performance in children after perinatal stroke

Mechanisms underlying cognitive impairment after perinatal stroke could be explained through brain network alterations. With aim to explore this connection, we conducted a matched test-control study to find a correlation between functional brain network properties and cognitive functions in children after perinatal stroke. First, we analyzed resting-state functional connectomes in the alpha frequency band from a 64-channel resting state EEG in 24 children with a history of perinatal stroke (12 with neonatal arterial ischemic stroke and 12 with neonatal hemorrhagic stroke) and compared them to the functional connectomes of 24 healthy controls. Next, all participants underwent cognitive evaluation. We analyzed the differences in functional brain network properties and cognitive abilities between groups and studied the correlation between network characteristics and specific cognitive functions. Functional brain networks after perinatal stroke had lower modularity, higher clustering coefficient, higher interhemispheric strength, higher characteristic path length and higher small world index. Modularity correlated positively with the IQ and processing speed, while clustering coefficient correlated negatively with IQ. Graph metrics, reflecting network segregation (clustering coefficient and small world index) correlated positively with a tendency to impulsive decision making, which also correlated positively with graph metrics, reflecting stronger functional connectivity (characteristic path length and interhemispheric strength). Our study suggests that specific cognitive functions correlate with different brain network properties and that functional network characteristics after perinatal stroke reflect poorer cognitive functioning.

Neuroimaging and Neurological Outcomes in Perinatal Arterial Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

Prediction of outcomes in perinatal arterial ischemic stroke (PAIS) is challenging. We performed a systematic review and meta-analysis to determine whether infarct characteristics can predict outcomes in PAIS.

METHODS

A systematic search was conducted using five databases in January 2023. Studies were included if the sample included children with neonatal or presumed PAIS; if infarct size, location, or laterality was indicated; and if at least one motor, cognitive, or language outcome was reported. The level of evidence and risk of bias were evaluated using the Risk of Bias in Non-Randomized Studies of Interventions tool. Meta-analyses were conducted comparing infarct size or location with neurological outcomes when at least three studies could be analyzed.

RESULTS

Eighteen full-text articles were included in a systematic review with nine included in meta-analysis. Meta-analyses revealed that small strokes were associated with a lower risk of cerebral palsy/hemiplegia compared with large strokes (risk ratio [RR] = 0.263, P = 0.001) and a lower risk of epilepsy (RR = 0.182, P < 0.001). Middle cerebral artery (MCA) infarcts were not associated with a significantly different risk of cerebral palsy/hemiplegia compared with non-MCA strokes (RR = 1.220, P = 0.337). Bilateral infarcts were associated with a 48% risk of cerebral palsy/hemiplegia, a 26% risk of epilepsy, and a 58% risk of cognitive impairment.

CONCLUSIONS

Larger stroke size was associated with worse outcomes across multiple domains. Widely heterogeneous reporting of infarct characteristics and outcomes limits the comparison of studies and the analysis of outcomes. More consistent reporting of infarct characteristics and outcomes will be important to advance research in this field.

Automated detection of abnormal general movements from pressure and positional information in hospitalized infants

BACKGROUND

Prechtl's general movements assessment (GMA) allows visual recognition of movement patterns that, when abnormal (cramped synchronized, or CS), have very high sensitivity in predicting later neuromotor disorders; however, training requirements and subjective perceptions from some clinicians may hinder universal adoption of the GMA in the newborn period.

METHODS

To address this, we used a three-phased approach to design a preliminary and clinically-oriented approach to automated CS GMA detection. 335 hospitalized infants were dually recorded on video and a pressure-sensor mat that collected time, spatial, and pressure data. Video recordings were scored by advanced GMA readers. We then conducted a series of unsupervised machine learning and supervised classification modeling with features extracted from clinician- and mat-driven datasets. Finally, the resulting algorithm was converted to a software interface.

RESULTS

A classification model combining normalization, clustering, and decision tree modeling resulted in the highest sensitivity for CS movements (100%). Results were delivered via the software interface within 20 min of data recording.

CONCLUSION

The combination of clinical research, machine learning, and repurposing of existing sensor mat technology produced a feasible preliminary approach to automatically detect abnormal GMA in infants while still in the NICU. Further refinements of software and algorithms are needed.

IMPACT STATEMENT

Machine learning can differentiate cramped synchronized general movement patterns in the neonatal intensive care unit with good sensitivity and specificity. Increasing access to the GMA through automated detection methods may allow for earlier identification of a greater number of children at high risk for movement delay. Large studies leveraging new artificial intelligence approaches could increase the impact of such detection.

Neuroimaging to guide neuroprognostication in the neonatal intensive care unit

PURPOSE OF REVIEW

Neurological problems are common in infants admitted to the neonatal intensive care unit (NICU). Various neuroimaging modalities are available for neonatal brain imaging and are selected based on presenting problem, timing and patient stability.

RECENT FINDINGS

Neuroimaging findings, taken together with clinical factors and serial neurological examination can be used to predict future neurodevelopmental outcomes. In this narrative review, we discuss neonatal neuroimaging modalities, and how these can be optimally utilized to assess infants in the NICU. We will review common patterns of brain injury and neurodevelopmental outcomes in hypoxic-ischemic encephalopathy, perinatal arterial ischemic stroke and preterm brain injury.

SUMMARY

Timely and accurate neuroprognostication can identify infants at risk for neurodevelopmental impairment and allow for early intervention and targeted therapies to improve outcomes.

Mesenchymal stem cell therapy in perinatal arterial ischemic stroke: systematic review of preclinical studies

BACKGROUND

Perinatal arterial ischemic stroke (PAIS) is a neurologic disorder leading to long-term complications. Mesenchymal stem cells (MSCs) have emerged as a novel therapeutic agent. This systematic review aims to determine the effects of stem cell-based interventions for the treatment of PAIS in preclinical studies.

METHODS

We included all controlled studies on MSCs in neonatal animals with PAIS. Functional outcome was the primary outcome. The literature search was performed in February 2021.

RESULTS

In the 20 included studies, MSCs were most frequently delivered via intracerebral injection (n = 9), 3 days after the induction of PAIS (n = 8), at a dose ranging from 5 × 104 to 5 × 106 cells. The meta-analysis showed an improvement on the cylinder rearing test (MD: -10.62; 95% CI: -14.38 to -6.86) and on the water maze test (MD: 1.31 MD; 95% CI: 0.80 to 1.81) in animals treated with MSCs compared to the control group animals.

CONCLUSION

MSCs appear to improve sensorimotor and cognitive performance in PAIS-injured animals; however, the certainty of the evidence is low. Registration of the protocol of preclinical studies, appropriate sample size calculation, rigorous randomization, and reporting of the data on animal sex and survival are warranted. PROSPERO registration number: CRD42021239642.

IMPACT

This is the first systematic review and meta-analysis of preclinical studies investigating the effects of MSCs in an experimental model of PAIS. MSCs appear to improve sensorimotor and cognitive performance in PAIS-injured neonatal animals. The certainty of the evidence is low due to high or unclear risk of bias in most domains.

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.

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.

Stroke in the Developing Brain: Neurophysiologic Implications of Stroke Timing, Location, and Comorbid Factors

BACKGROUND

Pediatric stroke, which is unique in that it represents a static insult to a developing brain, often leads to long-term neurological disability. Neuroplasticity in infants and children influences neurophysiologic recovery patterns after stroke; therefore outcomes depend on several factors including the timing and location of stroke and the presence of comorbid conditions.

METHODS

In this review, we discuss the unique implications of stroke occurring in the fetal, perinatal, and childhood/adolescent time periods. First, we highlight the impact of the developmental stage of the brain at the time of insult on the motor, sensory, cognitive, speech, and behavioral domains. Next, we consider the influence of location of stroke on the presence and severity of motor and nonmotor outcomes. Finally, we discuss the impact of associated conditions on long-term outcomes and risk for stroke recurrence.

RESULTS

Hemiparesis is common after stroke at any age, although the severity of impairment differs by age group. Risk of epilepsy is elevated in all age groups compared with those without stroke. Outcomes in other domains vary by age, although several studies suggest worse cognitive outcomes when stroke occurs in early childhood compared with fetal and later childhood epochs. Conditions such as congenital heart disease, sickle cell disease, and moyamoya increase the risk of stroke and leave patients differentially vulnerable to neurodevelopmental delay, stroke recurrence, silent infarcts, and cognitive impairment.

CONCLUSIONS

A comprehensive understanding of the interplay of various factors is essential in guiding the clinical care of patients with pediatric stroke.

The thalamus and basal ganglia are smaller in children with epilepsy after perinatal stroke

Background

Epilepsy is one of the most serious consequences of perinatal stroke. Epilepsy itself has been proposed as a risk factor for impaired cognitive, language, and behavioral functioning. It is still unclear which children develop epilepsy after perinatal stroke. The current study aimed to evaluate the volume of the thalamus and the basal ganglia in children after perinatal stroke in relation to poststroke epilepsy.

Methods

The follow-up study included 29 children with perinatal arterial ischemic stroke (AIS), 33 children with presumed periventricular venous infarction (PVI), and 46 age- and sex-matched healthy controls. Magnetic resonance imaging was performed in children between the ages of 4 and 18 years, and volumetric analysis by segmentation was used to evaluate the size of the thalamus, caudate nucleus, putamen, globus pallidus, hippocampus, amygdala, and nucleus accumbens.

Results

During a median follow-up time of 12.8 years [interquartile range (IQR): 10.8-17.3] in the AIS group and 12.5 years (IQR: 9.3-14.8) in the PVI group (p = 0.32), epilepsy developed in 10 children (34.5%) with AIS and in 4 (12.1%) children with PVI, p = 0.036 [odds ratio (OR) = 3.8, 95%, confidence interval (CI): 1.04-14]. Epilepsy and interictal epileptiform discharges (IEDs) without clinical seizures were more often expressed in children with AIS (n = 16, 55%) than in children with PVI (n = 7, 21.2%), p = 0.0057 (OR = 3.8 95% CI: 1.04-14). In the AIS group, the ipsilesional and contralesional thalamus, ipsilesional caudate nucleus, and nucleus accumbens were significantly smaller in children with epilepsy compared to children without epilepsy. In the PVI group, the ipsilesional thalamus, caudate nucleus, and nucleus accumbens were smaller in the pooled group of epilepsy plus IED alone compared to children without epilepsy.

Conclusion

In children with AIS, epilepsy or IED occurred more often compared to children with PVI. Both patients with AIS and PVI with severe damage to the basal ganglia and the thalamus have a higher risk of developing poststroke epilepsy and should be monitored more closely throughout childhood to initiate timely antiseizure medication and rehabilitation.

From Early Motor Ability to Global Cognitive Development 7 Years after Neonatal Arterial Ischemic Stroke

The developmental condition of children after neonatal arterial ischemic stroke (NAIS) is characterized by cognitive and motor impairments. We hypothesized that independent walking age would be a predictor of later global cognitive functioning in this population. Sixty-one children with an available independent walking age and full-scale intelligence quotient (IQ) score 7 years after NAIS were included in this study. Full-scale IQ was assessed using the fourth edition of the Wechsler Intelligence Scale for Children (WISC-IV). Independent walking age was negatively correlated with full-scale IQ score at 7 years of age (Pearson correlation coefficient of -0.27; 95% confidence interval from -0.48 to -0.01; p < 0.05). Early motor function is correlated with later global cognitive functioning in children after NAIS. Assessing and promoting early motor ability is essential in this population.

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.

TITLE: New therapeutic approaches in pediatric diseases: Mesenchymal stromal cell and mesenchymal stromal cell-derived extracellular vesicles as new drugs

Mesenchymal Stromal Cell (MSC) clinical applications have been widely reported and their therapeutic potential has been documented in several diseases. MSCs can be isolated from several human tissues and easily expanded in vitro, they are able to differentiate in a variety of cell lineages, and they are known to interact with most immunological cells, showing immunosuppressive and tissue repair properties. Their therapeutic efficacy is closely associated with the release of bioactive molecules, namely Extracellular Vesicles (EVs), effective as their parental cells. EVs isolated from MSCs act by fusing with target cell membrane and releasing their content, showing a great potential for the treatment of injured tissues and organs, and for the modulation of the host immune system. EV-based therapies provide, as major advantages, the possibility to cross the epithelium and blood barrier and their activity is not influenced by the surrounding environment. In the present review, we deal with pre-clinical reports and clinical trials to provide data in support of MSC and EV clinical efficacy with particular focus on neonatal and pediatric diseases. Considering pre-clinical and clinical data so far available, it is likely that cell-based and cell-free therapies could become an important therapeutic approach for the treatment of several pediatric diseases.

Massive Neonatal Arterial Ischemic Stroke

BACKGROUND

Massive infarction in adults is a devastating entity characterized by signs of extreme swelling of the brain's parenchyma. We explored whether a similar entity exists in neonates, which we call massive neonatal arterial ischemic stroke (M-NAIS), and assess its potential clinical implications.

METHODS

Prospective multicenter cohort study comprising 48 neonates with gestational age ≥35 weeks with middle cerebral artery (MCA) NAIS was performed. Diagnosis with magnetic resonance imaging (MRI) was performed within the first three days after symptom onset. The presence of signs of a space-occupying mass, such as brain midline shift and/or ventricular and/or extra-axial space collapse, was recorded. The volume of the infarct and brain midline shift were determined with semiautomatic procedures. Neurodevelopment was assessed at age 24 months.

RESULTS

Fifteen (31%) neonates presented MRI signs of a space-occupying mass effect and were considered to have an M-NAIS. The relative volume (infarct volume/total brain volume) of the infarct was on average significantly greater in the M-NAIS subgroup (29% vs 4.9%, P < 0.001). Patients with M-NAIS consistently presented lesions involving the M1 arterial territory of the MCA and showed more apneic and tonic seizures, which had an earlier onset and lasted longer. Moderate to severe adverse neurodevelopmental outcomes were present in most M-NAIS cases (79% vs 6%, P < 0.001).

CONCLUSIONS

M-NAIS appears to be a distinctive subtype of neonatal infarction, defined by characteristic neuroimaging signs. Neonates with M-NAIS frequently present a moderate to severe adverse outcome. Early M-NAIS identification would allow for prompt, specific rehabilitation interventions and would provide more accurate prognostic information to families.

Modeling Distal Middle Cerebral Artery Occlusion in Neonatal Rodents with Magnetic Nanoparticles or Magnetized Red Blood Cells

It is challenging to establish animal models to mimic perinatal arterial ischemic stroke. Here, we provided two approaches that precisely occlude rodent pups' distal middle cerebral artery of rodent pups at any postnatal age. One uses magnetic nanoparticles to generate platelet-rich thrombus, and the other utilizes magnetized red blood cells (mRBCs) to generate an erythrocyte-rich embolus. Both approaches result in focal cerebral ischemia followed by controllable reperfusion while requiring no arterial surgery.

miR-101-3p improves neuronal morphology and attenuates neuronal apoptosis in ischemic stroke in young mice by downregulating HDAC9

Objective

MiRNAs play a key role in ischemic stroke (IS). Although miR-101-3p can participate in multiple disease processes, its role and mechanism in IS are not clear. The aim of the present study was to observe the effect of miR-101-3p activation on IS in young mice and the role of HDAC9 in this effect.

Methods

The young mice were first subjected to transient middle cerebral artery occlusion (tMCAO) or sham surgery, and the cerebral infarct area was assessed with 2,3,5-triphenyltetrazolium chloride staining. Meanwhile, the expressions of miR-101-3p and HDAC9 were tested using RT-qPCR or western blot. Besides, neuron morphology and apoptosis were confirmed using Nissl staining and TUNEL staining.

Results

We first verified that miR-101-3p was downregulated and HDAC9 was upregulated in the brain tissue of tMCAO young mice. Moreover, we proved that overexpression of miR-101-3p could improve cerebral infarction, neuronal morphology, and neuronal apoptosis in tMCAO young mice by lowering the expression of HDAC9.

Conclusions

Activation of miR-101-3p can protect against IS in young mice, and its mechanism is relevant to the inhibition of HDAC9. Therefore, miR-101-3p and HDAC9 might be the latent targets for IS therapy.

Early predictors of neurodevelopment after perinatal arterial ischemic stroke: a systematic review and meta-analysis

BACKGROUND AND AIMS

Perinatal arterial ischemic stroke (PAIS) often has lifelong neurodevelopmental consequences. We aimed to review early predictors (<4 months of age) of long-term outcome.

METHODS

We carried out a systematic literature search (PubMed and Embase), and included articles describing term-born infants with PAIS that underwent a diagnostic procedure within four months of age, and had any reported outcome parameter ≥12 months of age. Two independent reviewers included studies and performed risk of bias analysis.

RESULTS

We included 41 articles reporting on 1395 infants, whereof 1255 (90%) infants underwent follow-up at a median of 4 years. A meta-analysis was performed for the development of cerebral palsy (n = 23 studies); the best predictor was the qualitative or quantitative assessment of the corticospinal tracts on MRI, followed by standardized motor assessments. For long-term cognitive functioning, bedside techniques including (a)EEG and NIRS might be valuable. Injury to the optic radiation on DTI correctly predicted visual field defects. No predictors could be identified for behavior, language, and post-neonatal epilepsy.

CONCLUSION

Corticospinal tract assessment on MRI and standardized motor assessments are best to predict cerebral palsy after PAIS. Future research should be focused on improving outcome prediction for non-motor outcomes.

IMPACT

We present a systematic review of early predictors for various long-term outcome categories after perinatal arterial ischemic stroke (PAIS), including a meta-analysis for the outcome unilateral spastic cerebral palsy. Corticospinal tract assessment on MRI and standardized motor assessments are best to predict cerebral palsy after PAIS, while bedside techniques such as (a)EEG and NIRS might improve cognitive outcome prediction. Future research should be focused on improving outcome prediction for non-motor outcomes.

Neurological and Functional Outcomes after Pediatric Stroke

Pediatric stroke results in life-long morbidity for many patients, but the outcomes can vary depending on factors such as age of injury, or mechanism, size, and location of stroke. In this review, we summarize the current understanding of outcomes in different neurological domains (eg, motor, cognitive, language) for children with stroke of different mechanisms (ie, arterial ischemic stroke, cerebral sinus venous thrombosis, and hemorrhagic stroke), but with a focus on World Health Organization International Classification for Functioning, Disability, and Health (ICF-CY) framework for measuring health and disability for children and youth. We describe outcomes for the population as a whole and certain factors that may further refine prognostication.

An exploratory study to identify neonatal arterial ischemic stroke: A single-center study

BACKGROUND

Neonatal arterial ischemic stroke (NAIS) presents as seizures, including convulsions, subtle seizures, and apnea, and most patients experience neurological sequelae. Diagnosis is often delayed owing to low test sensitivity. The present study aimed to identify the early clinical diagnostic factors for NAIS in neonates with seizures.

METHODS

The present study included 54 patients born at ≥36 weeks of gestation during the last 15 years who presented to the neonatal intensive care unit with neonatal seizures and underwent brain magnetic resonance imaging (MRI), 6 of whom were diagnosed with NAIS. Maternal background, clinical characteristics, and transcranial pulsed Doppler sonography results were retrospectively reviewed.

RESULTS

Of the 24 patients who presented with convulsions or subtle seizures, 3 (13%) were diagnosed with NAIS and 3 of 30 patients (10%) presented with apnea. Maternal premature ventricular contraction complications were higher in the NAIS group than in the non-NAIS group (p = 0.01). NAIS group showed lower mean middle cerebral artery (MCA) resistance index (RI) was lower the non-NAIS group (p = 0.009), while the left-right RI difference (p = 0.019), mean MCA blood velocity (MnV; p = 0.04), and left-right MnV difference (p < 0.001) in cerebral blood flow velocities (CBFVs) were higher in the NAIS group.

CONCLUSIONS

Our results revealed that maternal arrhythmia may be a diagnostic factor for NAIS in neonates with seizures. Early brain MRI is essential in neonates with seizures and findings of low MCA-RI, high MCA-MnV, or high left-right difference in CBFVs to distinguish between NAIS and non-NAIS.

Perinatal Stroke in Fetuses, Preterm and Term Infants

Perinatal stroke is a well-defined heterogenous group of disorders involving a focal disruption of cerebral blood flow between 20 weeks gestation and 28 days of postnatal life. The most focused lifetime risk for stroke occurs during the first week after birth. The morbidity of perinatal stroke is high, as it is the most common cause of hemiparetic cerebral palsy which results in lifelong disability that becomes more apparent throughout childhood. Perinatal strokes can be classified by the timing of diagnosis (acute or retrospective), vessel involved (arterial or venous), and underlying cause (hemorrhagic or ischemic). Perinatal stroke has primarily been reported as a disorder of term infants; however, the preterm brain possesses different vulnerabilities that predispose an infant to stroke injury both in utero and after birth. Accurate diagnosis of perinatal stroke syndromes has important implications for investigations, management, and prognosis. The classification of perinatal stroke by age at presentation (fetal, preterm neonatal, term neonatal, and infancy/childhood) is summarized in this review, and includes detailed descriptions of risk factors, diagnosis, treatment, outcomes, controversies, and resources for family support.

Perinatal Ischemic Stroke: Etiology and Imaging

Perinatal ischemic stroke is a common cause of lifelong disability.

Long-term neurodevelopmental outcome of neonates born at term with perinatal haemorrhagic stroke: A population-based study

AIM

To assess the long-term neurodevelopmental outcome of neonates born at term diagnosed with perinatal haemorrhagic stroke (PHS) and investigate the associations among brain territorial involvement, clinical risk factors, and neurodevelopmental outcomes.

METHOD

We conducted a population-based study enrolling 55 neonates born at term with PHS confirmed by magnetic resonance imaging born between 2007 and 2017. Long-term neurodevelopmental outcome was assessed using the Bayley Scales of Infant Development, Second Edition, the Brunet-Lézine test, and the Stanford-Binet Intelligence Scales, Fifth Edition.

RESULTS

Follow-up was available in 50 (91%) of the infants, at a median age of 60 months (interquartile range 35-88). Forty per cent of the infants developed according to population norms, and developmental disabilities were diagnosed less frequently among neonates with frontal lobe PHS. In a multivariable model, parietal lobe PHS increased the risk for cerebral palsy (odds ratio [OR] 6.7; 95% confidence interval [CI] 1.1-41.4) and cognitive impairment (OR: 23.6; 95% CI: 2.9-194.9), while the involvement of the thalamus and/or basal ganglia was associated with epilepsy (OR: 7.0; 95% CI: 1.3-37.7). Seizures on admission were associated with epilepsy (OR: 10.8; 95% CI: 1.8-64.3). Patients with PHS affecting multiple lobes had poor prognosis.

INTERPRETATION

Parietal lobe haemorrhage, the involvement of the thalamus/basal ganglia, PHS affecting multiple lobes, and seizures were independent predictors of chronic neurodevelopmental sequelae, suggesting that the stroke territorial involvement and clinical risk factors influence the outcome of PHS.

Risk of Autism After Pediatric Ischemic Stroke: A Nationwide Cohort Study

BACKGROUND AND OBJECTIVES

Ischemic stroke increases the risk of neurodevelopmental disorders; however, the risk of autism is not thoroughly explored. Our aim was to evaluate risk of autism and risk factors for autism in children with pediatric ischemic stroke and in their first-degree relatives.

METHODS

In this cohort study, individuals with ischemic stroke from 1969 to 2016, <18 years of age, alive 1 week after stroke, and without prior autism were identified in Swedish national registers. Ten matched controls per index individual and all first-degree relatives of index individuals and controls were identified. Conditional Cox regression was used to calculate the risk of autism. Unconditional logistic regression was performed to analyze sex, gestational age, age at stroke diagnoses, comorbid adverse motor outcome, comorbid epilepsy, and a sibling with autism as risk factors for autism in children with ischemic stroke.

RESULTS

Of the 1,322 index individuals, 46 (3.5%) were diagnosed with autism compared to 161 (1.2%) controls (adjusted hazard ratio [aHR] 3.02, 95% CI 2.15-4.25). There was no significant difference in risk of autism according to age at stroke: perinatal (aHR 2.69, 95% CI 1.44-5.03) and childhood stroke (aHR 3.18, 95% CI 2.12-4.78). The increased risk remained after exclusion of children born preterm or small for gestational age (aHR 3.78, 95% CI 2.55-5.60) and when children with stroke diagnosed from 1997 to 2014 were analyzed (aHR 2.91, 95% CI = 1.95-4.35). Compared to controls, the risk of autism was increased in individuals with ischemic stroke and comorbid epilepsy (aHR 7.05, 95% CI 3.74-13.30), as well as adverse motor outcome (aHR 4.28, 95% CI 2.44-7.51). When individuals with adverse motor outcome and epilepsy were censored, the risk of autism was still increased (aHR 2.37, 95% CI 1.45-3.85). Sex, gestational age, and having a sibling with autism were not associated with autism in individuals with pediatric ischemic stroke.

DISCUSSION

An increased risk of autism was seen after pediatric ischemic stroke, particularly in individuals with comorbid epilepsy, and could not be explained by being born preterm or small for gestational age. The risk was increased also in individuals free from epilepsy and adverse motor outcome, implying that all children with ischemic stroke should be readily screened for autism if the disorder is suspected.

Adverse motor outcome after paediatric ischaemic stroke: A nationwide cohort study

BACKGROUND

Various frequencies of adverse motor outcomes (cerebral palsy and hemiplegia) after paediatric ischaemic stroke have been reported. Few reports on the risks of adverse motor outcomes in nationwide cohorts and contributing risk factors are available.

OBJECTIVES

To assess risk of adverse motor outcome and potential risk factors thereof after paediatric ischaemic stroke in a nationwide cohort.

METHODS

This nationwide matched cohort study identified 877 children <18 years of age diagnosed with ischaemic stroke through the Swedish national health registers from 1997 to 2016. These children, exposed to ischaemic stroke, alive 1 week after stroke, were matched for age, sex and county of residence with 10 unexposed children. Using Cox regression, we estimated the risk of adverse motor outcomes in children with stroke compared to that in unexposed children. Logistic regression was applied to compare the characteristics of children with and without adverse motor outcomes after stroke.

RESULTS

Out of the 877 children with ischaemic stroke, 280 (31.9%) suffered adverse motor outcomes compared with 21 (0.2%) of the 8770 unexposed: adjusted hazard ratio (aHR) 167.78 (95% confidence interval (CI) 107.58, 261.66). There were no differences between risk estimates of adverse motor outcome according to age at stroke: perinatal stroke (aHR 124.11, 95% CI 30.45, 505.84) and childhood stroke (aHR 182.37, 95% CI 113.65, 292.64). An association between adverse motor outcome and childhood stroke aOR 1.56 (95% CI 1.05, 2.31) was found when analysing only children with ischaemic stroke. No associations were found between adverse motor outcome and sex, gestational age or parental age at birth.

CONCLUSIONS

The risk of adverse motor outcome is substantial after paediatric ischaemic stroke, especially childhood stroke, confirming results of previous smaller studies. This study found no associations between sex, gestational age or parental age and adverse motor outcome after paediatric ischaemic stroke.

Association of Perinatal and Childhood Ischemic Stroke With Attention-Deficit/Hyperactivity Disorder

IMPORTANCE

Early detection of attention-deficit/hyperactivity disorder (ADHD) plays a crucial role in reducing negative effects on everyday life, including academic failure and poor social functioning. Children who survive ischemic strokes risk major disabilities, but their risk of ADHD has not been studied in nationwide cohorts.

OBJECTIVE

To assess the risk of ADHD in children after pediatric ischemic stroke.

DESIGN, SETTING, AND PARTICIPANTS

Participants in this Swedish nationwide cohort study included 1320 children diagnosed with ischemic stroke recorded in linked Swedish national registers from January 1, 1969, to December 31, 2016, without prior ADHD diagnosis. Ten matched controls were identified for each index case, and first-degree relatives were identified for index individuals and controls. Analyses were stratified by perinatal and childhood strokes and presence of comorbid adverse motor outcomes and/or epilepsy. End of follow-up was the date of ADHD diagnosis, death, or December 31, 2016, whichever occurred first. Data analyses were performed August 1 to 28, 2021.

EXPOSURES

Pediatric ischemic stroke.

MAIN OUTCOMES AND MEASURES

Attention-deficit/hyperactivity disorder identified using codes from the International Classification of Diseases, Ninth Revision, and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, and/or prescribed ADHD medication recorded in the Medical Birth Register, National Patient Register, or Prescribed Drug Register after stroke. Cox proportional hazards regression was used to assess adjusted hazard ratios (aHRs) for ADHD after pediatric stroke, adjusting for parental age and ADHD in first-degree relatives.

RESULTS

Of 1320 children with stroke included in the analysis (701 boys [53.1%]), 75 (45 boys [60.0%]) were diagnosed with ADHD after stroke compared with 376 (252 boys [67.0%]) among the controls (aHR, 2.00 [95% CI, 1.54-2.60]). The risk was increased after both perinatal (aHR, 2.75 [95% CI ,1.65-4.60]) and childhood (aHR, 1.82 [95% CI, 1.34-2.48]) strokes and were similar if children born preterm or small for gestational age were excluded. Compared with controls, risks of ADHD were higher among children with perinatal stroke and adverse motor outcomes and/or epilepsy (aHR, 6.17 [95% CI, 2.80-13.62]) than among those without these comorbidities (aHR, 1.65 [95% CI, 0.80-3.42]). However, findings were similar in childhood stroke for children with adverse motor outcomes and/or epilepsy (aHR, 1.80 [95% CI, 1.12-2.89]) and among those without these comorbidities (aHR, 1.92 [95% CI, 1.28-2.90]).

CONCLUSIONS AND RELEVANCE

This cohort study of 1320 children with pediatric ischemic stroke suggests that there is an increased risk of ADHD, particularly in children with adverse motor outcomes and/or epilepsy, compared with controls. The risk increases after childhood strokes regardless of comorbidities.

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.

Precise control of embolic stroke with magnetized red blood cells in mice

Precise embolism control in immature brains can facilitate mechanistic studies of brain damage and repair after perinatal arterial ischemic stroke (PAIS), but it remains a technical challenge. Microhemorrhagic transformation is observed in one-third of infant patients who have suffered PAIS, but the underlying mechanism remains elusive. Building on an established approach that uses magnetic nanoparticles to induce PAIS, we develop a more advanced approach that utilizes magnetized erythrocytes to precisely manipulate de novo and in situ embolus formation and reperfusion in perinatal rodent brains. This approach grants spatiotemporal control of embolic stroke without any transarterial delivery of pre-formed emboli. Transmission electron microscopy revealed that erythrocytes rather than nanoparticles are the main material obstructing the vessels. Both approaches can induce microbleeds as an age-dependent complication; this complication can be prevented by microglia and macrophage depletion. Thus, this study provides an animal model mimicking perinatal embolic stroke and implies a potential therapeutic strategy for the treatment of perinatal stroke.

Neonatal arterial stroke location is associated with outcome at 2 years: a voxel-based lesion-symptom mapping study

OBJECTIVE

In contrast to motor impairments, the association between lesion location and cognitive or language deficits in patients with neonatal arterial ischaemic stroke remains largely unknown. We conducted a voxel-based lesion-symptom mapping cross-sectional study aiming to reveal neonatal arterial stroke location correlates of language, motor and cognitive outcomes at 2 years of age.

DESIGN

Prospective observational multicentre study.

SETTING

Six paediatric university hospitals in Spain.

PARTICIPANTS

We included 53 patients who had a neonatal arterial ischaemic stroke with neonatal MRI and who were followed up till 2 years of age.

MAIN OUTCOME MEASURES

We analysed five dichotomous clinical variables: speech therapy (defined as the need for speech therapy as established by therapists), gross motor function impairment, and the language, motor and cognitive Bayley scales. All the analyses were controlled for total lesion volume.

RESULTS

We found that three of the clinical variables analysed significantly correlated with neonatal stroke location. Speech therapy was associated with lesions located mainly at the left supramarginal gyrus (p=0.007), gross motor function impairment correlated with lesions at the left external capsule (p=0.044) and cognitive impairment was associated with frontal lesions, particularly located at the left inferior and middle frontal gyri (p=0.012).

CONCLUSIONS

The identification of these susceptible brain areas will allow for more precise prediction of neurological impairments on the basis of neonatal brain MRI.

Arterial ischemic stroke in children with congenital heart diseases

BACKGROUND

We describe the prevalence, thromboembolic risk factors, and neurologic outcomes in children with congenital heart disease (CHD) and arterial ischemic stroke (AIS).

METHODS

We retrospectively analyzed the clinical data of children with CHD and AIS from 2000 to 2016. Demographics, procedural and postprocedural data, neuroimaging findings, details of antithrombotic treatment, and neurological status at last follow up were evaluated.

RESULTS

Patients with cyanotic CHD accounted for 24 of 30 cases with AIS. The majority of AIS (70%) was procedure related, and the mean time from procedure to diagnosis of stroke was 9.7 (range, 1-30) days. At the time of AIS, 14 (46.7%) patients revealed coexistence of additional thromboembolic causes of AIS. Three patients (10.0%) experienced recurrent AIS and six patients (20.0%) were diagnosed with post-stroke epilepsy. The unfavorable outcomes were found in 13 patients (43.3%), including four deaths. The unfavorable outcome was significantly associated with the main branch involvement of middle cerebral artery (OR = 10.296, 95% CI = 1.335-79.439) and hemorrhagic transformation (OR = 16.264, 95% CI = 1.359-194.690).

CONCLUSIONS

Additional thromboembolic risk factors such as systemic or cardiac thrombus, arrhythmia, and surgical procedures for cyanotic CHD were found in patients with CHD and AIS. The main branch involvement of middle cerebral artery and hemorrhagic transformation were significant predictors of unfavorable outcomes. Further studies are required to identify the target for stroke prevention and develop better prophylactic strategies to minimize AIS in patients with CHD.

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.

Neonatal stroke: Clinical characteristics and neurodevelopmental outcomes

BACKGROUND

Neonatal stroke can potentially result in significant neurological sequelae in affected infants. Studies on neurodevelopmental outcomes and the need for rehabilitation therapies in the first two years are limited. We aimed to describe the clinical characteristics, diagnostic evaluation, and neurodevelopmental outcomes of a cohort of infants with neonatal stroke.

METHODS

A retrospective cohort study of infants with neonatal stroke, from 2011 to 2020. Maternal and infant characteristics were described. Placental pathology, echocardiogram results, and prothrombotic evaluations were reported. The neurodevelopmental outcomes using Bayley scale of infant development (BSID III), rates of epilepsy and cerebral palsy, and the need for rehabilitation therapies at two years were described.

RESULTS

During the study period, 55 infants had neonatal stroke. Majority (93%) were term or late preterm infants. Maternal chorioamnionitis and perinatal HIE were diagnosed in about a third of the infants. Most (66%) of the infants presented with seizures. On brain MRI, the lesions were unilateral in 76% and arterial in origin in 86% of the infants. Meconium exposure (42%), intrauterine inflammation/infection (37%) and fetal vascular malperfusion (16%) were seen on placental histopathology. At two-year BSID III assessment, median (min, max) composite cognitive, language, and motor scores were 100 (55-145), 97 (47-124), and 100 (46-141), respectively. Among this cohort, epilepsy (27%), cerebral palsy (16%) and the need for rehabilitation therapies (physical -24%, occupational -18%, speech -21%) were reported at two years.

CONCLUSION

Neonatal stroke presented commonly in term or late preterm infants with seizures. It was unilateral and arterial in origin in most infants. Maternal chorioamnionitis and perinatal HIE were the most commonly associated conditions at birth. About one-fifth of the infants had mild or severe developmental delays at two years. Epilepsy, cerebral palsy, and need for rehabilitation therapies were noted in a significant proportion of infants at two years.

A Uniform Description of Perioperative Brain MRI Findings in Infants with Severe Congenital Heart Disease: Results of a European Collaboration

BACKGROUND AND PURPOSE

A uniform description of brain MR imaging findings in infants with severe congenital heart disease to assess risk factors, predict outcome, and compare centers is lacking. Our objective was to uniformly describe the spectrum of perioperative brain MR imaging findings in infants with congenital heart disease.

MATERIALS AND METHODS

Prospective observational studies were performed at 3 European centers between 2009 and 2019. Brain MR imaging was performed preoperatively and/or postoperatively in infants with transposition of the great arteries, single-ventricle physiology, or left ventricular outflow tract obstruction undergoing cardiac surgery within the first 6 weeks of life. Brain injury was assessed on T1, T2, DWI, SWI, and MRV. A subsample of images was assessed jointly to reach a consensus.

RESULTS

A total of 348 MR imaging scans (180 preoperatively, 168 postoperatively, 146 pre- and postoperatively) were obtained in 202 infants. Preoperative, new postoperative, and cumulative postoperative white matter injury was identified in 25%, 30%, and 36%; arterial ischemic stroke, in 6%, 10%, and 14%; hypoxic-ischemic watershed injury in 2%, 1%, and 1%; intraparenchymal cerebral hemorrhage, in 0%, 4%, and 5%; cerebellar hemorrhage, in 6%, 2%, and 6%; intraventricular hemorrhage, in 14%, 6%, and 13%; subdural hemorrhage, in 29%, 17%, and 29%; and cerebral sinovenous thrombosis, in 0%, 10%, and 10%, respectively.

CONCLUSIONS

A broad spectrum of perioperative brain MR imaging findings was found in infants with severe congenital heart disease. We propose an MR imaging protocol including T1-, T2-, diffusion-, and susceptibility-weighted imaging, and MRV to identify ischemic, hemorrhagic, and thrombotic lesions observed in this patient group.

The role of brain territorial involvement and infection/inflammation in the long-term outcome of neonates with arterial ischemic stroke: A population-based cohort study

BACKGROUND

Neonatal arterial ischemic stroke (NAIS) carries the risk of significant long-term neurodevelopmental burden on survivors.

AIMS

To assess the long-term neurodevelopmental outcome of term neonates diagnosed with NAIS and investigate the associations among brain territorial involvement on MRI, clinical risk factors and neurodevelopmental outcomes.

STUDY DESIGN

Population-based cohort study.

SUBJECTS

Seventy-nine term neonates with NAIS confirmed by MRI born between 2007 and 2017.

OUTCOME MEASURES

Long-term neurodevelopmental outcome assessed using the Bayley Scales of Infant Development-II, the Brunet-Lézine test and the Binet Intelligence scales-V.

RESULTS

Follow-up was available in 70 (89%) of the subjects enrolled, at a median age of 60 months [IQR: 35-84]. Normal neurodevelopmental outcome was found in 43% of the patients. In a multivariable model, infants with main MCA stroke had an increased risk for overall adverse outcome (OR: 9.1, 95% CI: 1.7-48.0) and a particularly high risk for cerebral palsy (OR: 55.9, 95% CI: 7.8-399.2). The involvement of the corticospinal tract without extensive stroke also increased the risk for cerebral palsy/fine motor impairment (OR: 13.5, 95% CI: 2.4-76.3). Multiple strokes were associated with epilepsy (OR: 9.5, 95% CI: 1.0-88.9) and behavioral problems (OR: 4.4, 95% CI: 1.1-17.5) and inflammation/infection was associated with cerebral palsy (OR: 9.8, 95% CI: 1.4-66.9), cognitive impairment (OR: 9.2, 95% CI: 1.8-47.8) and epilepsy (OR: 10.3, 95% CI: 1.6-67.9).

CONCLUSIONS

Main MCA stroke, involvement of the corticospinal tract, multiple strokes and inflammation/infection were independent predictors of adverse outcome, suggesting that the interplay of stroke territorial involvement and clinical risk factors influence the outcome of NAIS.

New insights into glial scar formation after spinal cord injury

Severe spinal cord injury causes permanent loss of function and sensation throughout the body. The trauma causes a multifaceted torrent of pathophysiological processes which ultimately act to form a complex structure, permanently remodeling the cellular architecture and extracellular matrix. This structure is traditionally termed the glial/fibrotic scar. Similar cellular formations occur following stroke, infection, and neurodegenerative diseases of the central nervous system (CNS) signifying their fundamental importance to preservation of function. It is increasingly recognized that the scar performs multiple roles affecting recovery following traumatic injury. Innovative research into the properties of this structure is imperative to the development of treatment strategies to recover motor function and sensation following CNS trauma. In this review, we summarize how the regeneration potential of the CNS alters across phyla and age through formation of scar-like structures. We describe how new insights from next-generation sequencing technologies have yielded a more complex portrait of the molecular mechanisms governing the astrocyte, microglial, and neuronal responses to injury and development, especially of the glial component of the scar. Finally, we discuss possible combinatorial therapeutic approaches centering on scar modulation to restore function after severe CNS injury.

Neuroprotection of the Perinatal Brain by Early Information of Cerebral Oxygenation and Perfusion Patterns

Abnormal patterns of cerebral perfusion/oxygenation are associated with neuronal damage. In preterm neonates, hypoxemia, hypo-/hypercapnia and lack of cerebral autoregulation are related to peri-intraventricular hemorrhages and white matter injury. Reperfusion damage after perinatal hypoxic ischemia in term neonates seems related with cerebral hyperoxygenation. Since biological tissue is transparent for near infrared (NIR) light, NIR-spectroscopy (NIRS) is a noninvasive bedside tool to monitor brain oxygenation and perfusion. This review focuses on early assessment and guiding abnormal cerebral oxygenation/perfusion patterns to possibly reduce brain injury. In term infants, early patterns of brain oxygenation helps to decide whether or not therapy (hypothermia) and add-on therapies should be considered. Further NIRS-related technical advances such as the use of (functional) NIRS allowing simultaneous estimation and integrating of heart rate, respiration rate and monitoring cerebral autoregulation will be discussed.

Perinatal Stroke: A Practical Approach to Diagnosis and Management

Perinatal stroke is a focal vascular brain injury that occurs from the fetal period to 28 days of postnatal age. With an overall incidence of up to 1 in 1,000 live births, the most focused lifetime risk for stroke occurs near birth. Perinatal stroke can be classified by the timing of diagnosis, vessel involvement, and type of injury. Timing of diagnosis may be in the acute neonatal period or retrospectively after a period of normal development, followed by abnormal neurologic findings, with the injury presumed to have occurred around the time of birth. Strokes may be arterial or venous, ischemic, and/or hemorrhagic. Within these classifications, 6 perinatal stroke diseases are recognizable, based on clinical and radiographic features. Morbidity is high in perinatal stroke, because it accounts for most cases of hemiparetic cerebral palsy, with disability lasting a lifetime. Additional complications include disorders of sensation and vision, language delays, cognitive and learning deficits, epilepsy, and mental health consequences that affect the entire family. Advances in neonatal neurocritical care may afford opportunity to minimize brain injury and improve outcomes. In the chronic timeframe, progress made in neuroimaging and brain mapping is revealing the developmental plasticity that occurs, informing new avenues for neurorehabilitation. This review will summarize the diagnosis and management of each perinatal stroke disease, highlighting their similarities and distinctions and emphasizing a patient- and family-centered approach to management.

Non-verbal Intelligence in Unilateral Perinatal Stroke Patients With and Without Epilepsies

Background: The risk factors for impaired cognitive development after unilateral perinatal stroke are poorly understood. Non-verbal intelligence seems to be at particular risk, since language can shift to the right hemisphere and may thereby reduce the capacity of the right hemisphere for its originary functions. Pharmaco-refractory epilepsies, a frequent complication of perinatal strokes, often lead to impaired intelligence. Yet, the role of well-controlled epilepsies is less well-understood. Here, we investigated whether well-controlled epilepsies, motor impairment, lesion size, lesion side, and lateralization of language functions influence non-verbal functions. Methods: We recruited 8 patients with well-controlled epilepsies (9-26 years), 15 patients without epilepsies (8-23 years), and 23 healthy controls (8-27 years). All underwent the Test of Non-verbal Intelligence, a motor-independent test, which excludes biased results due to motor impairment. Language lateralization was determined with functional MRI, lesion size with MRI-based volumetry, and hand motor impairment with the Jebson-Taylor Hand Function-Test. Results: Patients with epilepsies showed significantly impaired non-verbal intelligence [Md = 89.5, interquartile range (IQR) = 13.5] compared with controls (Md = 103, IQR = 17). In contrast, patients without epilepsies (Md = 97, IQR = 15.0) performed within the range of typically developing children. A multiple regression analysis revealed only epilepsy as a significant risk factor for impaired non-verbal functions. Conclusion: In patients with unilateral perinatal strokes without epilepsies, the neuroplastic potential of one healthy hemisphere is able to support the development of normal non-verbal cognitive abilities, regardless of lesion size, lesion side, or language lateralization. In contrast, epilepsy substantially reduces this neuroplastic potential; even seizure-free patients exhibit below-average non-verbal cognitive functions.

Perinatal Arterial Ischemic Stroke

Perinatal arterial ischemic stroke (PAIS) is a common cause of seizures, encephalopathy, altered mental status, and focal neurologic deficits in the neonatal period. It is the leading known cause of cerebral palsy. Other long-term risks include the development of epilepsy and impairment in cognition, language, and behavior. This article will review the known risk factors for PAIS, as well as the evaluation, management, and prognosis. Long-term neurodevelopmental surveillance is recommended, along with intensive therapies to reduce morbidity.

Motor outcome after perinatal stroke and early prediction of unilateral spastic cerebral palsy

BACKGROUND

Unilateral spastic cerebral palsy (USCP) occurs in 30%-68% of infants with perinatal stroke. Early detection of USCP is essential for referring infants to early intervention. The aims of this study were to report motor outcomes after perinatal stroke, and to determine the predictive value of the General Movements Assessment (GMA) and Hand Assessment for Infants (HAI) for detection of USCP.

MATERIALS AND METHODS

This was a prospective observational study involving infants with perinatal stroke. GMA was conducted between 10 and 15 weeks post term-age (PTA). The HAI was performed between 3 and 5 months PTA. Motor outcome was collected between 12 and 36 months PTA.

RESULTS

The sample consisted of 46 infants. Fifteen children (32.6%) were diagnosed with CP, two children with bilateral CP and 13 with USCP. Abnormal GMA had a sensitivity of 85% (95% confidence interval [CI] 55-98%) and a specificity of 52% (95% CI 33-71%) to predict USCP. When asymmetrically presented FMs were also considered as abnormal, sensitivity increased to 100%, hence the specificity declined to 43%. A HAI asymmetry index cut-off of 23, had both a sensitivity and a specificity of 100% to detect USCP.

CONCLUSION

Using GMA and HAI can enable prediction of USCP before the age of 5 months in infants with perinatal stroke. Nevertheless, GMA must be interpreted with caution in this particular population. The HAI was found to be a very accurate screening tool for early detection of asymmetry and prediction of USCP.

Perinatal Arterial Ischemic Stroke in Fetal Vascular Malperfusion: A Case Series and Literature Review

Fetal vascular malperfusion includes a continuum of placental histologic abnormalities increasingly associated with perinatal brain injury, namely arterial ischemic stroke. Here, we describe the clinical-neuroimaging features of 5 neonates with arterial ischemic stroke and histologically proved fetal vascular malperfusion. All infarcts involved the anterior territories and were multiple in 2 patients. In 2 neonates, there were additional signs of marked dural sinus congestion, thrombosis, or both. A mixed pattern of chronic hypoxic-ischemic encephalopathy and acute infarcts was noted in 1 patient at birth. Systemic cardiac or thrombotic complications were present in 2 patients. These peculiar clinical-radiologic patterns may suggest fetal vascular malperfusion and should raise the suspicion of this rare, underdiagnosed condition carrying important implications in patient management, medicolegal actions, and future pregnancy counseling.

Precise neonatal arterial ischemic stroke classification with a three-dimensional map of the arterial territories of the neonatal brain

INTRODUCTION

Data regarding neonatal arterial ischemic stroke (NAIS) topography are still sparse and inaccurate. Despite the importance of locating NAIS to predict the long-term outcome of neonates, a map of arterial territories is not yet available. Our aim was therefore to generate the first three-dimensional map of arterial territories of the neonatal brain (ATNB) and test its usefulness.

METHODS

Three-dimensional time-of-flight magnetic resonance angiography images were acquired from four neonates without NAIS. Arteries were semi-automatically segmented to build a symmetric arterial template. This allowed us to delineate the volumetric extension of each arterial territory, giving rise to the ATNB map, which is publicly available. Its applicability was tested on a sample of 34 neonates with NAIS.

RESULTS

After applying the ATNB map to the neonatal sample, the posterior trunk of the middle cerebral artery, followed by its anterior trunk, were identified as the most affected arterial territories. When comparing the results obtained employing the map with the original diagnoses made during the standard clinical evaluation of NAIS, major diagnostic errors were found in 18% of cases.

CONCLUSION

The ATNB map has been proven useful to precisely identify the arterial territories affected by an NAIS, as well as to increase the accuracy of clinical diagnoses.

Early prediction of unilateral cerebral palsy in infants at risk: MRI versus the hand assessment for infants

BACKGROUND

Neonates with unilateral perinatal brain injury (UPBI) are at risk for developing unilateral spastic cerebral palsy (USCP). This study compares several predictors for USCP later in life.

METHODS

Twenty-one preterm and 24 term born infants with UPBI were included, with an MRI scan including diffusion tensor imaging (DTI) performed at term equivalent age or around 3 months after birth, respectively. T2-weighted images and DTI-based tractography were used to measure the surface area, diameter, and fractional anisotropy (FA) of both corticospinal tracts (CSTs). The hand assessment for infants (HAI) was performed before 5, between 5 and 8 and between 8 and 12 months of (corrected) age. Asymmetry indices were derived from all techniques and related to USCP at ≥2 years of age.

RESULTS

MRI measures and HAI scores were significantly lower for the affected compared to the unaffected side. Before 5 months of age, FA asymmetry on DTI yielded the highest area under the curve compared to conventional MRI and HAI.

CONCLUSIONS

Prediction of USCP after UPBI is reliable using asymmetry of the CST on MRI, as well as clinical hand assessment. Before 5 months of age, DTI tractography provides strongest predictive information, while HAI specifically aids to prognosis of USCP at later age points.

Methylprednisolone Reduces Persistent Post-ischemic Inflammation in a Rat Hypoxia-Ischemia Model of Perinatal Stroke

In perinatal stroke, the initial injury results in a chronic inflammatory response caused by the release of proinflammatory cytokines, gliosis and microglia activation. This chronic and ongoing inflammatory response exacerbates the brain injury, often resulting in encephalopathy and cerebral palsy (CP). Using a neonatal rat model of hypoxia-ischemia (HI) at postnatal day (P)7, we demonstrated that chronic inflammation is persistent and continues into the tertiary phase of perinatal stroke and can be attenuated by the administration of methylprednisolone sodium-succinate (MPSS, 30 mg/kg), a US Food and Drug Administration (FDA) approved anti-inflammatory agent. The inflammatory response was assessed by real-time quantitative PCR and ELISA for markers of inflammation (CCL3, CCL5, IL18 and TNFα). Structural changes were evaluated by histology (LFB/H&E), while cellular changes were assessed by Iba-1, ED1, GFAP, NeuN, Olig2 and CC1 immunostaining. Functional deficits were assessed with the Cylinder test and Ladder Rung Walking test. MPSS was injected 14 days after HI insult to attenuate chronic inflammation. In neonatal conditions such as CP, P21 is a clinically relevant time-point in rodents, corresponding developmentally to a 2-year-old human. Administration of MPSS resulted in reduced structural damage (corpus callosum, cortex, hippocampus, striatum), gliosis and reactive microglia and partial restoration of the oligodendrocyte population. Furthermore, significant behavioural recovery was observed. In conclusion, we demonstrated that administration of MPSS during the tertiary phase of perinatal stroke results in attenuation of the chronic inflammatory response, leading to pathophysiological and functional recovery. This work validates the high clinical impact of MPSS to treat neonatal conditions linked to chronic inflammation.

Neuron-specific enolase is correlated with lesion topology, relative infarct volume and outcome of symptomatic NAIS

OBJECTIVE

To correlate neuron-specific enolase (NSE) levels in cerebrospinal fluid (CSF) in neonate infants with symptomatic neonatal arterial ischaemic stroke (NAIS) with the arterial distribution of infarct, infarct volume and outcome.

DESIGN

Prospective observational multicentre cohort.

SETTING

Three paediatric university hospitals in Spain.

SUBJECTS

Thirty-eight neonates with more than 35 weeks' gestational age between 2006 and 2016 were studied. They were diagnosed with NAIS by MRI. They underwent a lumbar puncture to measure CSF-NSE concentrations within 96 hours after the onset of symptoms. Sixty-seven neonates admitted with suspected infections served as controls. We used a classification based on the arterial distribution, and the lesions were segmented with ITK-Snap software to determine their volume. Neurodevelopment was assessed at 24 months using the Bayley-III, Gross Motor Function Classification System and Bimanual Fine Motor Function.

RESULTS

CSF-NSE levels were higher in patients with symptomatic NAIS when compared with controls. Neonates with multifocal NAIS and with NAIS located in middle cerebral artery (MCA)-M1 arterial territory showed higher CSF-NSE levels when compared with cases with MCA-M2-M3-M4 territories (p<0.001). A significant correlation was found between CSF-NSE and relative infarction volume (r_s=0.597; p<0.001). CSF-NSE values were higher in those infants with symptomatic NAIS with adverse outcome compared with infants with good development (p=0.020). Infants with CSF-NSE values above 55 ng/mL had an OR of adverse outcome of 6.48 (95% CI 1.48 to 28.33).

CONCLUSIONS

CSF-NSE is a potential early prognostic biomarker after an NAIS due to the relation between volume, topology and neurodevelopment at 2 years of age.

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.

Cognitive and Academic Outcomes Following Childhood Cortical Stroke

The majority of pediatric neuropsychological stroke research has focused on perinatal stroke outcomes given its relative frequency. Meanwhile, childhood-onset stroke is under-represented in the literature, resulting in limited knowledge about its neurocognitive sequelae. This retrospective study examined cognitive outcomes in children and youth (n = 27) with childhood arterial ischemic stroke (stroke occurring between 29 days and 18 years of life) isolated to the cortical region. Intellectual, academic, language, visual-perception, visual-motor integration, fine motor coordination, and executive function scores were examined relative to normative means. Results indicate that although these children are doing well in terms of general intellectual ability, they demonstrate lower scores on tasks of processing speed and fine motor coordination. Exploratory analysis also revealed that of the personal and neurologic factors examined, age at stroke was positively correlated with perceptual reasoning and fine motor control, age at assessment was negatively correlated with math calculation abilities, and maternal education was positively correlated with working memory and parent-reported behavioral regulation and impulse inhibition abilities. While neurologic variables were not predictive of cognitive neuropsychological outcomes, those with significant poorer performance had higher rates of medium/large, right-sided lesions with frontal lobe involvement. Our results highlight the overall resilience of the injured developing brain but also the vulnerability of specific cognitive skills within this unique population.

Brain Activity and Cerebral Oxygenation After Perinatal Arterial Ischemic Stroke Are Associated With Neurodevelopment

Background and Purpose- In infants with perinatal arterial ischemic stroke (PAIS), early prognosis of neurodevelopmental outcome is important to adequately inform parents and caretakers. Early continuous neuromonitoring after PAIS may improve early prognosis. Our aim was to study early cerebral electrical activity and oxygenation measured by amplitude-integrated electroencephalography (aEEG) and near-infrared spectroscopy in term neonates with PAIS and relate these to the development of cerebral palsy and cognitive deficit. Methods- aEEG patterns and regional cerebral oxygen saturation (rScO2) levels of both hemispheres were studied for 120 hours from the first clinical symptoms of PAIS (ie, seizures) onward. Multivariable analyses were used to investigate the association between aEEG, near-infrared spectroscopy, clinical variables, and neurodevelopmental outcome. Results- In 52 patients with PAIS (gestational age, 40.4±1.4 weeks; birth weight, 3282±479 g), median time to a continuous background pattern was longer in the ipsilesional compared with the contralesional hemisphere (13.5 versus 10.0 hours; P<0.05). rScO2 decreased over time in both hemispheres but less in the ipsilesional one, resulting in a rScO2 asymmetry ratio of 4.5% (interquartile range, -4.3% to 5.9%; P<0.05) between hemispheres from day 3 after symptoms onward. Both time to normal background pattern and asymmetry in rScO2 were negatively affected by gestational age, size of the PAIS, use of antiepileptic drugs, and mechanical ventilation. After correction for size of the PAIS on magnetic resonance imaging, a slower recovery of background pattern on ipsilesional aEEG and increased rScO2 asymmetry between hemispheres was related with an increased risk for cognitive deficit (<-1 SD) at a median of 24.0 (interquartile range, 18.4-24.4) months of age. Conclusions- Recovery of background pattern on aEEG and cerebral oxygenation are both affected by PAIS and related to neurocognitive development. Both measurements may provide valuable early prognostic information. Additionally, monitoring cerebral activity and oxygenation may be useful in identifying infants eligible for early neuroprotective interventions and to detect early effects of these interventions.