Long term motor function after neonatal stroke: Lesion localization above all

Hand function after neonatal stroke: A graph model based on basal ganglia and thalami structure

INTRODUCTION

Neonatal arterial ischemic stroke (NAIS) is a common model to study the impact of a unilateral early brain insult on developmental brain plasticity and the appearance of long-term outcomes. Motor difficulties that may arise are typically related to poor function of the affected (contra-lesioned) hand, but surprisingly also of the ipsilesional hand. Although many longitudinal studies after NAIS have shown that predicting the occurrence of gross motor difficulties is easier, accurately predicting hand motor function (for both hands) from morphometric MRI remains complicated. The hypothesis of an association between the structural organization of the basal ganglia (BG) and thalamus with hand motor function seems intuitive given their key role in sensorimotor function. Neuroimaging studies have frequently investigated these structures to evaluate the correlation between their volumes and motor function following early brain injury. However, the results have been controversial. We hypothesize the involvement of other structural parameters.

METHOD

The study involves 35 children (mean age 7.3 years, SD 0.4) with middle cerebral artery NAIS who underwent a structural T1-weighted 3D MRI and clinical examination to assess manual dexterity using the Box and Blocks Test (BBT). Graphs are used to represent high-level structural information of the BG and thalami (volumes, elongations, distances) measured from the MRI. A graph neural network (GNN) is proposed to predict children's hand motor function through a graph regression. To reduce the impact of external factors on motor function (such as behavior and cognition), we calculate a BBT score ratio for each child and hand.

RESULTS

The results indicate a significant correlation between the score ratios predicted by our method and the actual score ratios of both hands (p < 0.05), together with a relatively high accuracy of prediction (mean L1 distance < 0.03). The structural information seems to have a different influence on each hand's motor function. The affected hand's motor function is more correlated with the volume, while the 'unaffected' hand function is more correlated with the elongation of the structures. Experiments emphasize the importance of considering the whole macrostructural organization of the basal ganglia and thalami networks, rather than the volume alone, to predict hand motor function.

CONCLUSION

There is a significant correlation between the structural characteristics of the basal ganglia/thalami and motor function in both hands. These results support the use of MRI macrostructural features of the basal ganglia and thalamus as an early biomarker for predicting motor function in both hands after early brain injury.

Executive functioning, ADHD symptoms and resting state functional connectivity in children with perinatal stroke

Perinatal stroke describes a group of focal, vascular brain injuries that occur early in development, often resulting in lifelong disability. Two types of perinatal stroke predominate, arterial ischemic stroke (AIS) and periventricular venous infarction (PVI). Though perinatal stroke is typically considered a motor disorder, other comorbidities commonly exist including attention-deficit hyperactivity disorder (ADHD) and deficits in executive function. Rates of ADHD symptoms are higher in children with perinatal stroke and deficits in executive function may also occur but underlying mechanisms are not known. We measured resting state functional connectivity in children with perinatal stroke using previously established dorsal attention, frontoparietal, and default mode network seeds. Associations with parental ratings of executive function and ADHD symptoms were examined. A total of 120 participants aged 6-19 years [AIS N = 31; PVI N = 30; Controls N = 59] were recruited. In comparison to typically developing peers, both the AIS and PVI groups showed lower intra- and inter-hemispheric functional connectivity values in the networks investigated. Group differences in between-network connectivity were also demonstrated, showing weaker anticorrelations between task-positive (frontoparietal and dorsal attention) and task-negative (default mode) networks in stroke groups compared to controls. Both within-network and between-network functional connectivity values were highly associated with parental reports of executive function and ADHD symptoms. These results suggest that differences in functional connectivity exist both within and between networks after perinatal stroke, the degree of which is associated with ADHD symptoms and executive function.

Structural networking of the developing brain: from maturation to neurosurgical implications

Modern neuroscience agrees that neurological processing emerges from the multimodal interaction among multiple cortical and subcortical neuronal hubs, connected at short and long distance by white matter, to form a largely integrated and dynamic network, called the brain "connectome." The final architecture of these circuits results from a complex, continuous, and highly protracted development process of several axonal pathways that constitute the anatomical substrate of neuronal interactions. Awareness of the network organization of the central nervous system is crucial not only to understand the basis of children's neurological development, but also it may be of special interest to improve the quality of neurosurgical treatments of many pediatric diseases. Although there are a flourishing number of neuroimaging studies of the connectome, a comprehensive vision linking this research to neurosurgical practice is still lacking in the current pediatric literature. The goal of this review is to contribute to bridging this gap. In the first part, we summarize the main current knowledge concerning brain network maturation and its involvement in different aspects of normal neurocognitive development as well as in the pathophysiology of specific diseases. The final section is devoted to identifying possible implications of this knowledge in the neurosurgical field, especially in epilepsy and tumor surgery, and to discuss promising perspectives for future investigations.

Association of Acute Infarct Topography With Development of Cerebral Palsy and Neurologic Impairment in Neonates With Stroke

BACKGROUND AND OBJECTIVES

Research investigating neonatal arterial ischemic stroke (NAIS) outcomes have shown that combined cortical and basal ganglia infarction or involvement of the corticospinal tract predict cerebral palsy (CP). The research question was whether voxel-based lesion-symptom mapping (VLSM) on acute MRI can identify brain regions associated with CP and neurodevelopmental impairments in NAIS.

METHODS

Newborns were recruited from prospective Australian and Swiss pediatric stroke registries. CP diagnosis was based on clinical examination. Language and cognitive-behavioral impairments were assessed using the Pediatric Stroke Outcome Measure, dichotomized to good (0-0.5) or poor (≥1), at ≥18 months of age. Infarcts were manually segmented using diffusion-weighted imaging, registered to a neonatal-specific brain template. VLSM was conducted using MATLAB SPM12 toolbox. A general linear model was used to correlate lesion masks with motor, language, and cognitive-behavioral outcomes. Voxel-wise t-statistics were calculated, correcting for multiple comparisons using family-wise error (FWE) rate.

RESULTS

Eighty-five newborns met the inclusion criteria. Infarct lateralization was left hemisphere (62%), right (8%), and bilateral (30%). At a median age of 2.1 years (interquartile range 1.9-2.6), 33% developed CP and 42% had neurologic impairments. Fifty-four grey and white matter regions correlated with CP (t > 4.33; FWE < 0.05), including primary motor pathway regions, such as the precentral gyrus, and cerebral peduncle, and regions functionally connected to the primary motor pathway, such as the pallidum, and corpus callosum motor segment. No significant correlations were found for language or cognitive-behavioral outcomes.

DISCUSSION

CP after NAIS correlates with infarct regions directly involved in motor control and in functionally connected regions. Areas associated with language or cognitive-behavioral impairment are less clear.

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.

SARS-CoV-2 Infection during Pregnancy Followed by Thalamic Neonatal Stroke-Case Report

A neonatal stroke is a cerebrovascular process caused by interruption of cerebral blood flow that occurs with an incidence between 1 per 1600 and 1 per 2660 live births. Relative higher incidence in the neonatal period compared to later childhood is favored by the hypercoagulability state of the mother, mechanical stress during delivery, transient right to left intracardiac shunt, high hematocrit, blood viscosity, and risk of dehydration during the first few days of life. The exact cause of a neonatal stroke remains unclear in many cases. About 80% of neonatal strokes are due to arterial ischemic events involving the middle cerebral artery. Typical clinical manifestations in a neonatal stroke are usually seizures that appear immediately after birth or after several days of life, but many of the cases may remain asymptomatic. We present the case of a late preterm infant diagnosed with a thalamic stroke on the fifth day of life with no clinical signs except for repeated episodes of apnea. The anamnesis and clinical context, in this case, revealed a SARS-CoV-2 infection in late pregnancy and early bacterial neonatal sepsis. Early identification of a perinatal stroke and increasing awareness of physicians about this condition in the neonatal period have paramount importance to reduce developmental postischemic damage.

Structural brain connectivity in children after neonatal stroke: A whole-brain fixel-based analysis

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Neonatal arterial ischemic stroke affects white matter distant from the lesion.

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Alterations are located ipsilesionally and in interhemispheric connections.

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Manual dexterity correlates with these structural impairments.

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The disseminated effects are therefore functionally relevant.

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Neonatal arterial ischemic stroke is a developmental network injury.

Introduction

Neonatal arterial ischemic stroke (NAIS) has been shown to affect white matter (WM) microstructure beyond the lesion. Here, we employed fixel-based analysis, a technique which allows to model and interpret WM alterations in complex arrangements such as crossing fibers, to further characterize the long-term effects of NAIS on the entire WM outside the primary infarct area.

Materials and methods

32 children (mean age 7.3 years (SD 0.4), 19 male) with middle cerebral artery NAIS (18 left hemisphere, 14 right hemisphere) and 31 healthy controls (mean age 7.7 years (SD 0.6), 16 male) underwent diffusion MRI scans and clinical examination for manual dexterity. Microstructural and macrostructural properties of the WM were investigated in a fixel-based whole-brain analysis, which allows to detect fiber-specific effects. Additionally, tract-averaged fixel metrics in interhemispheric tracts, and their correlation with manual dexterity, were examined.

Results

Significantly reduced microstructural properties were identified, located within the parietal and temporal WM of the affected hemisphere, as well as within their interhemispheric connecting tracts. Tract-averaged fixel metrics showed moderate, significant correlation with manual dexterity of the affected hand. No increased fixel metrics or contralesional alterations were observed.

Discussion

Our results show that NAIS leads to long-term alterations in WM microstructure distant from the lesion site, both within the parietal and temporal lobes as well as in their interhemispheric connections. The functional significance of these findings is demonstrated by the correlations with manual dexterity. The localization of alterations in structures highly connected to the lesioned areas shift our perception of NAIS from a focal towards a developmental network injury.

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.

Effects of gestational age at birth on perinatal structural brain development in healthy term-born babies

Infants born in early term (37-38 weeks gestation) experience slower neurodevelopment than those born at full term (40-41 weeks gestation). While this could be due to higher perinatal morbidity, gestational age at birth may also have a direct effect on the brain. Here we characterise brain volume and white matter correlates of gestational age at birth in healthy term-born neonates and their relationship to later neurodevelopmental outcome using T2 and diffusion weighted MRI acquired in the neonatal period from a cohort (n = 454) of healthy babies born at term age (>37 weeks gestation) and scanned between 1 and 41 days after birth. Images were analysed using tensor-based morphometry and tract-based spatial statistics. Neurodevelopment was assessed at age 18 months using the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III). Infants born earlier had higher relative ventricular volume and lower relative brain volume in the deep grey matter, cerebellum and brainstem. Earlier birth was also associated with lower fractional anisotropy, higher mean, axial, and radial diffusivity in major white matter tracts. Gestational age at birth was positively associated with all Bayley-III subscales at age 18 months. Regression models predicting outcome from gestational age at birth were significantly improved after adding neuroimaging features associated with gestational age at birth. This work adds to the body of evidence of the impact of early term birth and highlights the importance of considering the effect of gestational age at birth in future neuroimaging studies including term-born babies.

Ipsilesional volume loss of basal ganglia and thalamus is associated with poor hand function after ischemic perinatal stroke

BACKGROUND

Perinatal stroke (PS) is the leading cause of hemiparetic cerebral palsy (CP). Involvement of the corticospinal tract on neonatal magnetic resonance imaging (MRI) is predictive of motor outcome in patients with hemiparetic CP. However, early MRI is not available in patients with delayed presentation of PS and prediction of hemiparesis severity remains a challenge.

AIMS

To evaluate the volumes of the basal ganglia, amygdala, thalamus, and hippocampus following perinatal ischemic stroke in relation to hand motor function in children with a history of PS and to compare the volumes of subcortical structures in children with PS and in healthy controls.

METHODS

Term born PS children with arterial ischemic stroke (AIS) (n = 16) and with periventricular venous infarction (PVI) (n = 18) were recruited from the Estonian Pediatric Stroke Database. MRI was accuired during childhood (4-18 years) and the volumes of the basal ganglia, thalamus, amygdala and hippocampus were calculated. The results of stroke patients were compared to the results of 42 age- and sex-matched healthy controls. Affected hand function was evaluated by Assisting Hand Assessment (AHA) and classified by the Manual Ability Classification System (MACS).

RESULTS

Compared to the control group, children with AIS had smaller volumes of the ipsi- and contralesional thalami, ipsilesional globus pallidus, nucleus accumbens and hippocampus (p < 0.005). Affected hand function in children with AIS was correlated with smaller ipsilesional thalamus, putamen, globus pallidus, hippocampus, amygdala and contralesional amygdala (r > 0.5; p < 0.05) and larger volume of the contralesional putamen and hippocampus (r < - 0.5; p < 0.05). In children with PVI, size of the ipsilesional caudate nucleus, globus pallidus, thalamus (p ≤ 0.001) and hippocampus (p < 0.03) was smaller compared to controls. Smaller volume of the ipsi- and contralesional thalami and ipsilesional caudate nucleus was correlated with affected hand function (r > 0.55; p < 0.05) in children with PVI.

CONCLUSIONS

Smaller volume of ipsilesional thalamus was associated with poor affected hand function regardless of the perinatal stroke subtype. The pattern of correlation between hand function and volume differences in the other subcortical structures varied between children with PVI and AIS. Evaluation of subcortical structures is important in predicting motor outcome following perinatal stroke.

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.

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.

The predictive value of lesion and disconnectome loads for upper limb motor impairment after stroke

OBJECTIVE

The putative effect of lesion-induced brain damage on post-stroke upper limb motor impairment can be estimated by overlaying a patient's lesion or its surrogate with key motor areas. We assessed the predictive value of imaging-based brain damage measures for cross-sectional upper limb motor impairment and subsequent upper limb motor outcome after stroke.

METHODS

In 47 stroke patients, upper limb motor impairment was evaluated with the Upper-Extremity Fugl-Meyer Assessment (UE-FMA) at 2 weeks (2W) and 3 months (3M) post-stroke. Given each patient's lesion identified at 2W, we considered the disconnectome, estimated as an ensemble of structural and functional connections passing through the lesion, as a surrogate of the lesion. The lesion load and the disconnectome load were measured by overlaying the lesion and disconnectome with the corticospinal tract (CST) and motor cortex (MC), and their association with the UE-FMA score at 2W and 3M was assessed.

RESULTS

Whereas the disconnectome loads on the CST and MC were better in predicting the UE-FMA score at 2W, the lesion load on the CST was better in predicting the UE-FMA score at 3M. Furthermore, when the CST lesion load was combined with the UE-FMA score at 2W, the UE-FMA score at 3M was better predicted, with smaller generalization error, than by using either measure alone.

CONCLUSIONS

The combination of the CST lesion load and baseline upper limb motor impairment would provide a tailored fusion of imaging and clinical measures for more accurate motor outcome prediction.

Relationship between resting-state fMRI functional connectivity with motor and language outcome after perinatal brain injury - A systematic review

Perinatal brain injury is a significant cause of adverse neurodevelopmental outcomes. The objective of this systematic review was to identify patterns of altered brain function, quantified using functional connectivity (FC) changes in resting-state fMRI (rs-fMRI) data, that were associated with motor and language outcomes in individuals with a history of perinatal brain injury. A systematic search using electronic databases was conducted to identify relevant studies. A total of 10 studies were included in the systematic review, representing 260 individuals with a history of perinatal brain injury. Motor and language outcomes were measured at time points ranging from 4 months to 29 years 1 month. Relations between FC and motor measures revealed increased intra-hemispheric FC, reduced inter-hemispheric FC and impaired lateralization of motor-related brain regions associated with motor outcomes. Altered FC within sensorimotor, visual, cerebellum and frontoparietal networks, and between sensorimotor, visual, auditory and higher-order networks, including cerebellum, frontoparietal, default-mode, salience, self-referential and attentional networks were also associated with motor outcomes. In studies assessing the relationship between rs-fMRI and language outcome, reduced intra-hemispheric FC, increased inter-hemispheric FC and right-hemisphere lateralization of language-related brain regions correlated with language outcomes. Evidence from this systematic review suggests a possible association between diaschisis and motor and language impairments in individuals after perinatal brain lesions. These findings support the need to explore the contributions of additional brain regions functionally connected but remote from the primary lesioned brain area for targeted treatments and appropriate intervention, though more studies with increased standardization across neuroimaging and neurodevelopmental assessments are needed.

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.

Predictors of Neurological Outcome of Arterial Ischemic Stroke in Children

Stroke is an important cause of mortality and morbidity in children. The aim of the study was to evaluate long-term neurological outcome in children with arterial ischemic stroke (AIS) and explore predictive factors that affect poor outcome. Fifty-six patients aged between 1 month and 17 years who were treated at M. Iashvili Children's Central Hospital, Tbilisi, Georgia, with an onset of stroke from 2007 to 2017 were included. To explore predictive factors of outcome, the following data were collected: demographic characteristics, risk factors, he presenting signs, radiological features, and presence of stroke recurrence. Neurological status at discharge and long-term neurological outcome at least 1 year after stroke was evaluated according to Pediatric Stroke Outcome Measure subscale. The reported outcome after childhood stroke was variable with long-term neurological deficits in one-third of patients (30.4%). The neurological outcome was worse in males, in patients with multiple stroke episodes, and in those with infarctions involving a combination of cortical and subcortical areas. Pediatric AIS carries the risk of long-term morbidity, and neuroimaging has a predictive influence on outcome.

Relationship between motor abilities and executive functions in patients after pediatric stroke

Patients after pediatric stroke typically experience varying extent of motor and cognitive impairments. During rehabilitation, these impairments are often treated as separate entities. While there is a notion claiming that motor and cognitive functions are interrelated to some degree in healthy children, a minimal amount of evidence exists regarding this issue in patients after pediatric stroke. The purpose of this study was to investigate the association between motor abilities and executive functions in patients after pediatric arterial ischemic stroke. Twenty-seven patients (6 - 23 years) diagnosed with pediatric arterial ischemic stroke in the chronic phase (≥ 2 years after diagnosis, diagnosed < 16 years) and 49 healthy controls (6 - 26 years) were included in this study. Participants completed six tasks from standardized neuropsychological tests assessing the dimensions of executive functions, namely working memory, inhibition, and shifting. Additionally, we assessed hand strength and upper limb performance with two tasks each. In the patient group, the association between upper limb performance and executive functions was stronger than between hand strength and executive functions. Our results point toward the idea of a close interrelation between upper limb performance and executive functions. Training more complex and cognitively engaging motor abilities involving upper limb performance rather than basic motor abilities such as hand strength during a rehabilitation program may have the power to foster executive function development and vice versa in patients after stroke.

Short-term outcomes after a neonatal arterial ischemic stroke

PURPOSE

The purpose of this study is to determine the frequency and radiological predictors of recurrent acute symptomatic seizures (RASS) and motor impairment at discharge after a neonatal arterial ischemic stroke (NAIS).

METHODS

In a nonconcurrent cohort study, 33 full-term newborns with NAIS confirmed by MRI are admitted into our hospital between January 2003 and December 2012. Stroke size, calculated as stroke volume divided by whole brain volume (WBV), was categorized as > or < 3.3% of WBV. A univariate analysis of categorical variables was performed using Fisher's exact test. A multivariate analysis was performed using logistic regression models including all variables with a p value < 0.1 in the univariate analysis.

RESULTS

The median age at NAIS was 2 days (IQR, 1-5.6), 36.4% were girls. The stroke size was > 3.3 of WBV in 48.5% of the cases, and 54.5% showed multifocal lesions. Involvement of the cerebral cortex (54.5%), thalamus (48.5%), posterior limb of the internal capsule (36.4%), basal ganglia (36.4%), and brainstem (28.2%) were found. At discharge, 45.5% of newborns had a motor deficit, and 27.3% had at least two seizures. Multivariate analyses revealed that stroke size > 3.3% of WBV (OR: 8.1, CI: 1.2-53.9) and basal ganglia involvement (OR: 12.8, CI: 1.7-95.4) predicted motor impairment at discharge. Cortical involvement of temporal and frontal lobes (OR: 14, CI: 2.2-88.1; and OR: 9.1, CI: 1.2-72.6) were predictive of RASS.

CONCLUSION

Stroke size and location are independent risk factors for adverse short-term neurological outcomes in full-term newborns following a NAIS.

A connectome-based approach to assess motor outcome after neonatal arterial ischemic stroke

Objective

Studies of motor outcome after Neonatal Arterial Ischemic Stroke (NAIS) often rely on lesion mapping using MRI. However, clinical measurements indicate that motor deficit can be different than what would solely be anticipated by the lesion extent and location. Because this may be explained by the cortical disconnections between motor areas due to necrosis following the stroke, the investigation of the motor network can help in the understanding of visual inspection and outcome discrepancy. In this study, we propose to examine the structural connectivity between motor areas in NAIS patients compared to healthy controls in order to define the cortical and subcortical connections that can reflect the motor outcome.

Methods

Thirty healthy controls and 32 NAIS patients with and without Cerebral Palsy (CP) underwent MRI acquisition and manual assessment. The connectome of all participants was obtained from T1‐weighted and diffusion‐weighted imaging.

Results

Significant disconnections in the lesioned and contra‐lesioned hemispheres of patients were found. Furthermore, significant correlations were detected between the structural connectivity metric of specific motor areas and manuality assessed by the Box and Block Test (BBT) scores in patients.

Interpretation

Using the connectivity measures of these links, the BBT score can be estimated using a multiple linear regression model. In addition, the presence or not of CP can also be predicted using the KNN classification algorithm. According to our results, the structural connectome can be an asset in the estimation of gross manual dexterity and can help uncover structural changes between brain regions related to NAIS.

Aplicação da escala Spinal Alignment and Range of Motion Measure (SAROMM) em crianças e adultos com paralisia cerebral, em uma instituição de abrigagem de Porto Alegre (RS)

RESUMO O objetivo do estudo foi descrever o perfil de crianças e adultos institucionalizados com Paralisia Cerebral, bem como, suas alterações musculoesqueléticas, alinhamento da coluna vertebral e amplitude de movimento; também, traçar estratégias para minimizar o avanço das deformidades já instaladas. Estudo de caráter transversal e descritivo. Crianças e adultos com Paralisia Cerebral de uma Instituição de abrigagem da cidade de Porto Alegre/RS foram avaliados (n=28). Utilizou-se a escala Spinal Alignment and Range of Motion Measure (SAROMM) para avaliar as deformidades e Gross Motor Function Classification System (GMFCS) para classificar o nível funcional. 96% dos sujeitos foram do tipo espástico; 42,85% apresentaram nível motor V do total dos participantes; as maiores deformidades encontradas foram em joelho, quadril e coluna avaliados pela escala de SAROMM, associado com a idade mais avançada e quadro de quadriplegia espástica, com diagnóstico clínico em prontuário. Sujeitos maiores de 20 anos obtiveram uma pontuação média de 68,7 (varia de 0 a 104) e sujeitos menores de 20 anos, sua pontuação média foi de 55,1 pontos, sendo quanto menor, melhor o alinhamento e menos deformidades. Sujeitos com PC de um local de abrigagem apresentaram, na sua maioria, espasticidade do tipo bilateral dos quatro membros, nível de GMFCS predominante foi o V e alterações articulares em joelhos, quadril e coluna vertebral como maiores deformidades encontrada. As estratégias devem ser traçadas e iniciadas o mais cedo possível para diminuir e ou minimizar deformidades e a escala SAROMM pode ser uma escolha para avaliar esse público.

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.

Is the Blood Oxygenation Level-Dependent fMRI Response to Motor Tasks Altered in Children After Neonatal Stroke?

Functional MRI is increasingly being used in the assessment of brain activation and connectivity following stroke. Many of these studies rely on the Blood Oxygenation Level Dependent (BOLD) contrast. However, the stability, as well as the accuracy of the BOLD response to motor task in the ipsilesional hemisphere, remains ambiguous. In this work, the BOLD signal acquired from both healthy and affected hemispheres was analyzed in 7-year-old children who sustained a Neonatal Arterial Ischemic Stroke (NAIS). Accordingly, a repetitive motor task of the contralesional and the ipsilesional hands was performed by 33 patients with unilateral lesions. These patients were divided into two groups: those without cerebral palsy (NAIS), and those with cerebral palsy (CP). The BOLD signal time course was obtained from distinctly defined regions of interest (ROIs) extracted from the functional activation maps of 30 healthy controls with similar age and demographic characteristics as the patients. An ROI covering both the primary motor cortex (M1) and the primary somatosensory cortex (S1) was also tested. Compared with controls, NAIS patients without CP had similar BOLD amplitude variation for both the contralesional and the ipsilesional hand movements. However, in the case of NAIS patients with CP, a significant difference in the averaged BOLD amplitude was found between the healthy and affected hemisphere. In both cases, no progressive attenuation of the BOLD signal amplitude was observed throughout the task epochs. Besides, results also showed a correlation between the BOLD signal percentage variation of the lesioned hemisphere and the dexterity level. These findings suggest that for patients who sustained a NAIS with no extensive permanent motor impairment, BOLD signal-based data analysis can be a valuable tool for the evaluation of functional brain networks.

Functional, neuroplastic and biomechanical changes induced by early Hand-Arm Bimanual Intensive Therapy Including Lower Extremities (e-HABIT-ILE) in pre-school children with unilateral cerebral palsy: study protocol of a randomized control trial

BACKGROUND

Cerebral palsy (CP) causes motor, cognitive and sensory impairment at different extents. Many recent rehabilitation developments (therapies) have focused solely on the upper extremities (UE), although the lower extremities (LE) are commonly affected. Hand-arm Bimanual Intensive Therapy Including Lower Extremities (HABIT-ILE) applies the concepts of motor skill learning and intensive training to both the UE and LE. It involves constant stimulation of the UE and LE, for several hours each day over a 2-week period. The effects of HABIT-ILE have never been evaluated in a large sample of young children. Furthermore, understanding of functional, neuroplastic and biomechanical changes in infants with CP is lacking. The aim of this study is to carry out a multi-center randomized controlled trial (RCT) to evaluate the effects of HABIT-ILE in pre-school children with unilateral CP on functional, neuroplastic and biomechanical parameters.

METHODS

This multi-center, 3-country study will include 50 pre-school children with CP aged 1-4 years. The RCT will compare the effect of 50 h (two weeks) of HABIT-ILE versus usual motor activity, including regular rehabilitation. HABIT-ILE will be delivered in a day-camp setting, with structured activities and functional tasks that will be continuously progressed in terms of difficulty. Assessments will be performed at 3 intervals: baseline (T0), two weeks later and 3 months later. Primary outcomes will be the Assisting Hand Assessment; secondary outcomes include the Melbourne Assessment-2, executive function assessments, questionnaires ACTIVLIM-CP, Pediatric Evaluation of Disability Inventory, Young Children's Participation and Environment Measure, Measure of the Process of Care, Canadian Occupational Performance Measure, as well as neuroimaging and kinematics measures.

DISCUSSION

We expect that HABIT-ILE will induce functional, neuroplastic and biomechanical changes as a result of the intense, activity-based rehabilitation process and these changes will impact the whole developmental curve of each child, improving functional ability, activity and participation in the short-, mid- and long-term. Name of the registry: Changes Induced by Early HABIT-ILE in Pre-school Children With Uni- and Bilateral Cerebral Palsy (EarlyHABIT-ILE).

TRIAL REGISTRATION

Trial registration number: NCT04020354-Registration date on the International Clinical Trials Registry Platform (ICTRP): November 20th, 2018; Registration date on NIH Clinical Trials Registry: July 16th, 2019.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

The relationship between neuroimaging and motor outcome in children with cerebral palsy: A systematic review-Part B diffusion imaging and tractography

BACKGROUND

Diffusion magnetic resonance imaging (dMRI) is able to detect, localize and quantify subtle brain white matter abnormalities that may not be visible on conventional structural MRI. Over the past years, a growing number of studies have applied dMRI to investigate structure-function relationships in children with cerebral palsy (CP).

AIMS

To provide an overview of the recent literature on dMRI and motor function in children with CP.

METHODS

A systematic literature search was conducted in PubMed, Embase, Cochrane Central Register of Controlled trials, Cinahl and Web of Science from 2012 onwards.

RESULTS

In total, 577 children with CP in 19 studies were included. Sixteen studies only included unilateral CP, while none included dyskinetic CP. Most studies focused on specific regions/tracts of interest (n = 17) versus two studies that investigated the whole brain. In unilateral and bilateral CP, white matter abnormalities were widespread including non-motor areas. In unilateral CP, consistent relationships were found between white matter integrity of the corticospinal tract and somatosensory pathways (e.g. thalamocortical projections, medial lemniscus) with upper limb sensorimotor function. The role of commissural and associative tracts remains poorly investigated. Also results describing structure-function relationships in bilateral CP are scarce (n = 3).

CONCLUSIONS

This review underlines the importance of both the motor and somatosensory tracts for upper limb sensorimotor function in unilateral CP. However, the exact contribution of each tract requires further exploration. In addition, research on the relevance of non-motor pathways is warranted, as well as studies including other types of CP.

The new insights into human brain imaging after stroke

Over the last two decades, developments of human brain stroke imaging have raised several questions about the place of new MRI biomarkers in the acute management of stroke and the prediction of poststroke outcome. Recent studies have demonstrated the main role of perfusion-weighted imaging in the identification of the best cerebral perfusion profile for a better response after reperfusion therapies in acute ischemic stroke. A major issue remains the early prediction of stroke outcome. While voxel-based lesion-symptom mapping emphasized the influence of stroke location, the analysis of the brain parenchyma underpinning the stroke lesion showed the relevance of prestroke cerebral status, including cortical atrophy, white matter integrity, or presence of chronic cortical cerebral microinfarcts. Moreover, besides the evaluation of the visually abnormal brain tissue, the analysis of normal-appearing brain parenchyma using diffusion tensor imaging and magnetization transfer imaging or spectroscopy offered new biomarkers to improve the prediction of the prognosis and new targets to follow in therapeutic trials. The aim of this review was to depict the main new radiological biomarkers reported in the last two decades that will provide a more thorough prediction of functional, motor, and neuropsychological outcome following the stroke. These new developments in neuroimaging might be a cornerstone in the emerging personalized medicine for stroke patients.

From congenial paralysis to post-early brain injury developmental condition: Where does cerebral palsy actually stand?

Cerebral palsy (CP), an umbrella term for a developmental motor disorder caused by early brain injury (EBI)/interference, remains debated. In this essay, we present a narrative, beginning with the original anatomical-clinical description of the so-called paralysie congéniale (congenial paralysis) by the French psychiatrist Jean-Baptiste Cazauvieilh. We then discuss how the concept has evolved over the last 2 centuries. We aim to illustrate these ideas with the biopsychosocial model of health, especially in light of the current neuroscientific and sociological knowledge of human development. We endeavour to integrate 3 connected but distinct entities: (1) the EBI as a seminal turning point of the individual's story; (2) the clinical findings we call CP, when motor impairment and activity limitation related to post-EBI (or other early non-progressive brain interference) appears, and; (3) a post-EBI developmental condition that encompasses the overall consequences of an EBI. This framework should guide individual, familial and collective care discussions and research strategies beyond the scope of CP.

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.

Alterations in Cortical Morphology after Neonatal Stroke: Compensation in the Contralesional Hemisphere?

Although neonatal arterial ischemic stroke is now well-studied, its complex consequences on long-term cortical brain development has not yet been solved. In order to understand the brain development after focal early brain lesion, brain morphometry needs to be evaluated using structural parameters. In this work, our aim was to study and analyze the changes in morphometry of ipsi- and contralesional hemispheres in seven-year-old children following neonatal stroke. Therefore, we used surface-based morphometry in order to examine the cortical thickness, surface area, cortical volume, and local gyrification index in two groups of children that suffered from neonatal stroke in the left (n = 19) and right hemispheres (n = 15) and a group of healthy controls (n = 30). Reduced cortical thickness, surface area, and cortical volumes were observed in the ipsilesional hemispheres for both groups in comparison with controls. For the group with left-sided lesions, higher gyrification of the contralesional hemisphere was observed primarily in the occipital region along with higher surface area and cortical volume. As for the group with right-sided lesions, higher gyrification was detected in two separate clusters also in the occipital lobe of the contralesional hemisphere, without a significant change in cortical thickness, surface area, or cortical volume. This is the first time that alterations of structural parameters are detected in the "healthy" hemisphere after unilateral neonatal stroke indicative of a compensatory phenomenon. Moreover, findings presented in this work suggest that lesion lateralization might have an influence on brain development and maturation.

Motor function daily living skills 5 years after paediatric arterial ischaemic stroke: a prospective longitudinal study

AIM

To describe 5-year motor and functional outcomes after paediatric arterial ischaemic stroke (AIS) and to explore factors associated with poorer long-term outcome.

METHOD

Thirty-three children (21 males, 12 females) with AIS were recruited to a single-site, cross-sectional study, from a previously reported prospective longitudinal stroke outcome study. Children were stratified according to age at diagnosis: neonates (≤30d), preschool (>30d-5y), and school age (≥5y). Motor and functional outcomes were measured at 5 years after stroke. Neurological outcomes were evaluated using the Pediatric Stroke Outcome Measure (PSOM) at 1 month and more than 4 years after stroke.

RESULTS

At 5 years after stroke, motor function, quality of life, fatigue, adaptive behaviour, activities of daily living, and handwriting speed were significantly poorer than age expectations. The preschool group had the highest percentage of fine and gross motor impairment. Poorer fine motor skills were associated with subcortical-only lesions and large lesion size. Poorer gross motor outcomes correlated with preschool age, bilateral lesions, and PSOM impairment at 1 month.

INTERPRETATION

Children are at elevated risk for motor and functional impairments after AIS, with the preschool age group most vulnerable. Identifying early predictors of poorer outcomes facilitates targeted early intervention and long-term rehabilitation.

WHAT THIS PAPER ADDS

Following paediatric stroke, children are at elevated risk of motor and functional difficulties. Stroke occurring between 30 days and 5 years of age may result in poorer motor and functional outcomes.

Perinatal arterial ischemic stroke

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

Long-term neurodevelopmental outcome after perinatal arterial ischemic stroke and periventricular venous infarction

BACKGROUND

Long-term follow-up data after different vascular types of ischemic perinatal stroke is sparse. Our aim was to study neurodevelopmental outcomes following neonatal and presumed perinatal ischemic middle cerebral artery territory stroke (arterial ischemic stroke, AIS) and periventricular venous infarction (PVI).

METHODS

A prospective consecutive cohort of 40 term-born children with perinatal stroke (21 AIS, 19 PVI) was identified through the Estonian Paediatric Stroke Database. While 48% of the children with AIS were diagnosed during the neonatal period, all the children with PVI had presumed perinatal stroke. Outcomes based on the Paediatric Stroke Outcome Measure (PSOM) and Kaufman Assessment Battery for Children - Second Edition (K-ABC-II), in relation to extent and laterality of stroke, were defined.

RESULTS

At a median age of 7 years 6 months (range 3.6-13y), there was a trend towards worse neurodevelopmental outcome in participants with AIS when compared to PVI (mean total PSOM scores 3.1 and 2.2, respectively; p = 0.06). Combined deficits of motor, language and cognitive/behavioural functions were significantly more common among children with AIS (90%) when compared to children with PVI (53%, p = 0.007). General cognitive ability (by K-ABC-II) was significantly lower in the AIS subgroup (mean 79.6; 95% CI 72.3-87.0), but children with PVI (91.6; 95% CI 85.5-97.8) also had poorer performance than the age-equivalent normative mean. Large extent of stroke was associated with poorer neurodevelopmental outcome and lower cognitive performance in children following AIS but not in PVI.

CONCLUSION

In this national cohort, poor long-term neurodevelopmental outcome after perinatal ischemic stroke was seen irrespective of the vascular type or time of diagnosis of stroke. However, the spectrum of neurological deficits is different after perinatal AIS and PVI, with combined deficits more common among children following AIS.

Diagnosing cerebral palsy in full-term infants

More than 50% of infants with cerebral palsy (CP) are born at or near term, with the vast majority having pre- or perinatally acquired CP. While some have a clinical history predictive of CP, such as neonatal encephalopathy or neonatal stroke, others have no readily identifiable risk factors. Paediatricians are often required to discriminate generalised motor delay from a variety of other diagnoses, including CP. This paper outlines known causal pathways to CP in term-born infants with a focus on differential diagnosis. Early and accurate diagnosis is important as it allows prompt access to early intervention during the critical periods of brain development. A combination of clinical history taking, standard clinical examination, neuroimaging and genetic testing should be started at the time of referral. Attention to the investigation of common comorbidities of CP, including feeding and sleep difficulties, and referral to early intervention are recommended.

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.

Structural Brain Damage and Upper Limb Kinematics in Children with Unilateral Cerebral Palsy

Background: In children with unilateral cerebral palsy (uCP) virtually nothing is known on the relation between structural brain damage and upper limb (UL) kinematics quantified with three-dimensional movement analysis (3DMA). This explorative study aimed to (1) investigate differences in UL kinematics between children with different lesion timings, i.e., periventricular white matter (PWM) vs. cortical and deep gray matter (CDGM) lesions and (2) to explore the relation between UL kinematics and lesion location and extent within each lesion timing group. Methods: Forty-eight children (age 10.4 ± 2.7 year; 29 boys; 21 right-sided; 33 PWM; 15 CDGM) underwent an UL 3DMA during a reach-to-grasp task. Spatiotemporal parameters [movement duration, (timing of) maximum velocity, trajectory straightness], the Arm Profile Score (APS) and Arm Variable Scores (AVS) were extracted. The APS and AVS refer to the total amount of movement pathology and movement deviations of the wrist, elbow, shoulder, scapula and trunk respectively. Brain lesion location and extent were scored based on FLAIR-images using a semi-quantitative MRI-scale. Results: Children with CDGM lesions showed more aberrant spatiotemporal parameters (p < 0.03) and more movement pathology (APS, p = 0.003) compared to the PWM group, mostly characterized by increased wrist flexion (p = 0.01). In the CDGM group, moderate to high correlations were found between lesion location and extent and duration, timing of maximum velocity and trajectory straightness (r = 0.53-0.90). Lesion location and extent were further moderately correlated with distal UL movement pathology (wrist flexion/extension, elbow pronation/supination, elbow flexion/extension; r = 0.50-0.65) and with the APS (r = 0.51-0.63). In the PWM group, only a few and low correlations were observed, mostly between damage to the PLIC and higher AVS of elbow flexion/extension, shoulder elevation and trunk rotation (r = 0.35-0.42). Regression analysis revealed damage to the temporal lobe with lesion timing as interactor (27%, p = 0.002) and the posterior limb of the internal capsule (PLIC) (7%, p = 0.04) as the strongest predictors, explaining 34% of the variance in APS. Conclusion: UL kinematic deviations are more influenced by lesion location and extent in children with later (CDGM) versus earlier lesions (PWM), except for proximal movement pathology. Damage to the PLIC is a significant predictor for UL movement pathology irrespective of lesion timing.

Association of transcallosal motor fibres with function of both hands after unilateral neonatal arterial ischemic stroke

AIM

The objective of this study was to investigate the involvement of the motor fibres of the corpus callosum after unilateral neonatal arterial ischemic stroke (NAIS) of the middle cerebral artery territory and the relationship to both ipsilesional and contralesional hand function.

METHOD

Using high-resolution structural magnetic resonance imaging (MRI), functional MRI, and magnetic resonance diffusion-tractography, we compared the midsagittal area of the motor part of the corpus callosum (defined by the fibres connecting the precentral gyri) between 33 7-year-old children after unilateral NAIS and 31 typically developing 7-year-old children. Hand motor performance was assessed by the box and blocks test.

RESULTS

Children after NAIS showed on average significantly smaller motor corpus callosum area compared to typically developing children (p<0.001, without differences of the non-motor corpus callosum area). In addition, there was a significant positive association between the motor part of the corpus callosum and both contralesional (Pr(>|t|)=0.034) and ipsilesional hand motor performance (Pr(>|t|)=0.006) after controlling for lesion volume and sex. In a post-hoc analysis the additional contribution of corticospinal tract damage was evaluated.

INTERPRETATION

Compared to typically developing children, children after NAIS exhibited a smaller motor part of their corpus callosum associated with reduced contralesional but also ipsilesional manual dexterity. These results indicate that the affection of transcallosal motor fibres in unilateral NAIS might be of functional relevance and an important part of the involved structural network that should be elucidated in further studies.

Trajectories of Motor Recovery in the First Year After Pediatric Arterial Ischemic Stroke

BACKGROUND

Neuromotor impairments are common after pediatric stroke, but little is known about functional motor outcomes. We evaluated motor function and how it changed over the first 12 months after diagnosis. We also examined differences in outcome according to age at diagnosis and whether fine motor (FM) or gross motor (GM) function at 12 months was associated with adaptive behavior.

METHODS

This prospective, longitudinal study recruited children (N = 64) from The Royal Children's Hospital, Melbourne who were diagnosed with acute arterial ischemic stroke (AIS) between December 2007 and November 2013. Motor assessments were completed at 3 time points after the diagnosis of AIS (1, 6, and 12 months). Children were grouped as follows: neonates (n = 27), preschool-aged (n = 19), and school-aged (n = 18).

RESULTS

A larger lesion size was associated with poorer GM outcomes at 12 months (P = .016). Neonatal AIS was associated with better FM and GM function initially but with a reduction in z scores over time. For the preschool- and school-aged groups, FM remained relatively stable over time. For GM outcomes, the preschool- and the school-aged age groups displayed similar profiles, with gradual recovery over time. Overall, poor FM and GM outcomes at 12 months were associated with poorer adaptive behavior scores.

CONCLUSIONS

Motor outcomes and the trajectory of recovery post-AIS differed according to a child's age at stroke onset. These findings indicate that an individualized approach to surveillance and intervention may be needed that is informed in part by age at diagnosis.

The Potential for Advanced Magnetic Resonance Neuroimaging Techniques in Pediatric Stroke Research

BACKGROUND

This article was written to provide clinicians and researchers with an overview of a number of advanced neuroimaging techniques in an effort to promote increased utility and the design of future studies using advanced neuroimaging in childhood stroke. The current capabilities of advanced magnetic resonance imaging techniques provide the opportunity to build on our knowledge of the consequences of stroke on the developing brain. These capabilities include providing information about the physiology, metabolism, structure, and function of the brain that are not routinely evaluated in the clinical setting.

METHODS

During the Proceedings of the Stroke Imaging Laboratory for Children Workshop in Toronto in June 2015, a subgroup of clinicians and imaging researchers discussed how the application of advanced neuroimaging techniques could further our understanding of the mechanisms of stroke injury and repair in the pediatric population. This subgroup was established based on their interest and commitment to design collaborative, advanced neuroimaging studies in the pediatric stroke population.

RESULTS

In working toward this goal, we first sought to describe here the magnetic resonance imaging techniques that are currently available for use, and how they have been applied in other stroke populations (e.g., adult and perinatal stroke).

CONCLUSIONS

With the continued improvement in advanced neuroimaging techniques, including shorter acquisition times, there is an opportunity to apply these techniques to their full potential in the research setting and learn more about the effects of stroke in the developing brain.

Three-Dimensional Map of Neonatal Arterial Ischemic Stroke Distribution From Early Multimodal Brain Imaging

Background and Purpose—

Although neonatal arterial ischemic stroke (NAIS) location has considerable impact on long-term outcome, a map showing spatial distribution of NAIS is lacking. Our aim was to generate this distribution map, based on early magnetic resonance imaging data.

Methods—

Lesions from 34 consecutive neonates with NAIS from a single center were segmented using multimodal magnetic resonance imaging (median age at acquisition =5 days). Lesion masks for all subjects were registered onto a standard neonatal brain and then overlaid to generate a 3D map of NAIS distribution.

Results—

The region posterior to the central sulcus is the most frequently affected in neonates, with 24 of the 34 neonates (71%) showing lesions in this region in at least one hemisphere. Moreover, NAIS frequency is markedly higher in the left hemisphere.

Conclusions—

This is the first report of an NAIS distribution map. Regions posterior to the central sulcus present increased vulnerability. Our findings suggest that motor areas are not as frequently affected as has been previously reported. By contrast, we find high NAIS vulnerability in functional areas related to language. The distribution of ischemic strokes in neonates seems to be different from that seen in adults.

Verbal and musical short-term memory: Variety of auditory disorders after stroke

Auditory cognitive deficits after stroke may concern language and/or music processing, resulting in aphasia and/or amusia. The aim of the present study was to assess the potential deficits of auditory short-term memory for verbal and musical material after stroke and their underlying cerebral correlates with a Voxel-based Lesion Symptom Mapping approach (VLSM). Patients with an ischemic stroke in the right (N=10) or left (N=10) middle cerebral artery territory and matched control participants (N=14) were tested with a detailed neuropsychological assessment including global cognitive functions, music perception and language tasks. All participants then performed verbal and musical auditory short-term memory (STM) tasks that were implemented in the same way for both materials. Participants had to indicate whether series of four words or four tones presented in pairs, were the same or different. To detect domain-general STM deficits, they also had to perform a visual STM task. Behavioral results showed that patients had lower performance for the STM tasks in comparison with control participants, regardless of the material (words, tones, visual) and the lesion side. The individual patient data showed a double dissociation between some patients exhibiting verbal deficits without musical deficits or the reverse. Exploratory VLSM analyses suggested that dorsal pathways are involved in verbal (phonetic), musical (melodic), and visual STM, while the ventral auditory pathway is involved in musical STM.

Improvement in White Matter Tract Reconstruction with Constrained Spherical Deconvolution and Track Density Mapping in Low Angular Resolution Data: A Pediatric Study and Literature Review

INTRODUCTION

Diffusion-weighted magnetic resonance imaging (DW-MRI) allows noninvasive investigation of brain structure in vivo. Diffusion tensor imaging (DTI) is a frequently used application of DW-MRI that assumes a single main diffusion direction per voxel, and is therefore not well suited for reconstructing crossing fiber tracts. Among the solutions developed to overcome this problem, constrained spherical deconvolution with probabilistic tractography (CSD-PT) has provided superior quality results in clinical settings on adult subjects; however, it requires particular acquisition parameters and long sequences, which may limit clinical usage in the pediatric age group. The aim of this work was to compare the results of DTI with those of track density imaging (TDI) maps and CSD-PT on data from neonates and children, acquired with low angular resolution and low b-value diffusion sequences commonly used in pediatric clinical MRI examinations.

MATERIALS AND METHODS

We analyzed DW-MRI studies of 50 children (eight neonates aged 3-28 days, 20 infants aged 1-8 months, and 22 children aged 2-17 years) acquired on a 1.5 T Philips scanner using 34 gradient directions and a b-value of 1,000 s/mm². Other sequence parameters included 60 axial slices; acquisition matrix, 128 × 128; average scan time, 5:34 min; voxel size, 1.75 mm × 1.75 mm × 2 mm; one b = 0 image. For each subject, we computed principal eigenvector (EV) maps and directionally encoded color TDI maps (DEC-TDI maps) from whole-brain tractograms obtained with CSD-PT; the cerebellar-thalamic, corticopontocerebellar, and corticospinal tracts were reconstructed using both CSD-PT and DTI. Results were compared by two neuroradiologists using a 5-point qualitative score.

RESULTS

The DEC-TDI maps obtained presented higher anatomical detail than EV maps, as assessed by visual inspection. In all subjects, white matter (WM) tracts were successfully reconstructed using both tractography methodologies. The mean qualitative scores of all tracts obtained with CSD-PT were significantly higher than those obtained with DTI (p-value < 0.05 for all comparisons).

CONCLUSION

CSD-PT can be successfully applied to DW-MRI studies acquired at 1.5 T with acquisition parameters adapted for pediatric subjects, thus providing TDI maps with greater anatomical detail. This methodology yields satisfactory results for clinical purposes in the pediatric age group.

Perspectives in neonatal and childhood arterial ischemic stroke

INTRODUCTION

Over the last decade considerable advances have been made in the identification, understanding and management of pediatric arterial ischemic stroke. Such increasing knowledge has also brought new perspectives and interrogations in the current acute and rehabilitative care of these patients. Areas covered: In developed countries, focal cerebral arteriopathy is one of the most common causes of arterial ischemic stroke in childhood and imaging features are well characterized. However, there are ongoing debates regarding its underlying mechanisms, natural evolution and proper management. The implementation of thrombolytic therapy in acute pediatric stroke has been shown to be efficient in anecdotal cases but is still limited by a number of caveats, even in large tertiary centers. Finally, neonatal stroke represents a unique circumstance of possible early intervention before the onset of any neurological disability but this appears meaningful only in a selective group of neonates. Expert commentary: While perinatal stroke, a leading cause of cerebral palsy, appears to be multifactorial, a large number of childhood ischemic stroke are probably essentially triggered by infectious factors leading to vessel wall damage. Current research is aiming at better identifying risk factors in both conditions, and to define optimal acute and preventive therapeutic strategies in order to reduce significant long-term morbidity.

Does Contralesional Hand Function After Neonatal Stroke Only Depend on Lesion Characteristics?

Background and Purpose—

In children having suffered from neonatal arterial ischemic stroke, the relationship between contralesional hand performance and structural changes in brain areas remote from the infarct site was examined.

Methods—

Using voxel-based morphometry, we correlated contralesional gross manual dexterity assessed by the box and block test and whole-brain gray and white-matter volume changes on high-resolution magnetic resonance imaging in 37 7-year-old post–neonatal arterial ischemic stroke children. We also compared the volume of the identified structures with magnetic resonance imaging data of 10 typically developing age-matched children.

Results—

Areas showing the highest positive correlation with the box and block test scores were ipsilesional mediodorsal thalamus, contralesional cerebellar lobule VIIa Crus I, and ipsilesional corticospinal tract at the level of superior corona radiata, the posterior limb of the internal capsule, and the cerebral peduncle and the ipsilesional body of corpus callosum. When compared with typically developing age-matched children, post–neonatal arterial ischemic stroke children with severe contralesional hand motor deficit exhibited significant volume reductions in these structures (except the cerebellum), whereas no differences were found with those with good manual dexterity. No negative correlation was found between box and block test scores and brain areas.

Conclusions—

Contralesional hand performance after neonatal arterial ischemic stroke is correlated with atrophy in brain areas directly or functionally connected but anatomically remote from the infarct. Our study suggests a role of the cerebellar lobule VIIa Crus I and mediodorsal thalamus in manual dexterity.

Clinical Trial Registration—

URL: https://clinicaltrials.gov . Unique identifier: NCT02511249.

Multimodal Outcome at 7 Years of Age after Neonatal Arterial Ischemic Stroke

OBJECTIVES

To evaluate the epileptic, academic, and developmental status at age 7 years in a large population of term-born children who sustained neonatal arterial ischemic stroke (NAIS), and to assess the co-occurrence of these outcomes.

STUDY DESIGN

A cohort study including 100 term newborns with NAIS was designed. Two infants died during the neonatal period, 13 families were lost to follow-up, and 5 families declined to participate in this evaluation. Thus, 80 families completed the 7-year clinical assessment. Epileptic status, schooling, motor abilities, global intellectual functioning, spoken language, and parental opinions were recorded. Principal component analysis was applied.

RESULTS

Rates of impaired language, cerebral palsy, low academic skills, active epilepsy, and global intellectual deficiency were 49%, 32%, 28%, 11%, and 8%, respectively. All were highly correlated. Eventually, 59% of children were affected by at least 1 of the aforementioned conditions. In 30% of cases, the viewpoints of health practitioners and parents did not match.

CONCLUSION

The prevalence of severe disabilities at 7 years after NAIS is low, but most children exhibit some impairment in developmental profile.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02511249), Programme Hospitalier de Recherche Clinique Régional (0308052), Programme Hospitalier de Recherche Clinique Interrégional (1008026), and EudraCT (2010-A00329-30).