The development of the pediatric stroke neuroimaging platform (PEDSNIP)

Childhood stroke occurs from birth to 18 years of age, ranks among the top ten childhood causes of death, and leaves lifelong neurological impairments. Arterial ischemic stroke in infancy and childhood occurs due to arterial occlusion in the brain, resulting in a focal lesion. Our understanding of mechanisms of injury and repair associated with focal injury in the developing brain remains rudimentary. Neuroimaging can reveal important insights into these mechanisms. In adult stroke population, multi-center neuroimaging studies are common and have accelerated the translation process leading to improvements in treatment and outcome. These studies are centered on the growing evidence that neuroimaging measures and other biomarkers (e.g., from blood and cerebrospinal fluid) can enhance our understanding of mechanisms of risk and injury and be used as complementary outcome markers. These factors have yet to be studied in pediatric stroke because most neuroimaging studies in this population have been conducted in single-centred, small cohorts. By pooling neuroimaging data across multiple sites, larger cohorts of patients can significantly boost study feasibility and power in elucidating mechanisms of brain injury, repair and outcomes. These aims are particularly relevant in pediatric stroke because of the decreased incidence rates and the lack of mechanism-targeted trials. Toward these aims, we developed the Pediatric Stroke Neuroimaging Platform (PEDSNIP) in 2015, funded by The Brain Canada Platform Support Grant, to focus on three identified neuroimaging priorities. These were: developing and harmonizing multisite clinical protocols, creating the infrastructure and methods to import, store and organize the large clinical neuroimaging dataset from multiple sites through the International Pediatric Stroke Study (IPSS), and enabling central searchability. To do this, developed a two-pronged approach that included building 1) A Clinical-MRI Data Repository (standard of care imaging) linked to clinical data and longitudinal outcomes and 2) A Research-MRI neuroimaging data set acquired through our extensive collaborative, multi-center, multidisciplinary network. This dataset was collected prospectively in eight North American centers to test the feasibility and implementation of harmonized advanced Research-MRI, with the addition of clinical information, genetic and proteomic studies, in a cohort of children presenting with acute ischemic stroke. Here we describe the process that enabled the development of PEDSNIP built to provide the infrastructure to support neuroimaging research priorities in pediatric stroke. Having built this Platform, we are now able to utilize the largest neuroimaging and clinical data pool on pediatric stroke data worldwide to conduct hypothesis-driven research. We are actively working on a bioinformatics approach to develop predictive models of risk, injury and repair and accelerate breakthrough discoveries leading to mechanism-targeted treatments that improve outcomes and minimize the burden following childhood stroke. This unique transformational resource for scientists and researchers has the potential to result in a paradigm shift in the management, outcomes and quality of life in children with stroke and their families, with far-reaching benefits for other brain conditions of people across the lifespan.

Roadmap for the Assessment and Management of Outcomes in Pediatric Stroke

Neurological morbidity is common after pediatric stroke, with moderate to severe deficits that can significantly impact education and social function. Care and recovery occur in phases distinguished by the time interval after stroke onset. These phases include the hyperacute and acute periods in which the focus is on cerebral reperfusion and prevention of neurological deterioration, followed by the subacute and chronic phases in which the focus is on secondary stroke prevention and mitigation of disability through rehabilitation, adaptation, and reintegration into the community. In this article, a multidisciplinary group of pediatric stroke experts review the stages of recovery after pediatric stroke with an emphasis on critical assessment time points. Our goal is to encourage increased standardization of outcome assessment to facilitate future clinical trials comparing various treatment and intervention options and advance optimized care for children with stroke.

Early Discontinuation of Phenobarbital After Acute Symptomatic Neonatal Seizures in the Term Newborn

Acute symptomatic seizures in the term newborn are often seen after perinatal brain injury. Common etiologies include hypoxic-ischemic encephalopathy, ischemic stroke, intracranial hemorrhage, metabolic derangements, and intracranial infections. Neonatal seizures are often treated with phenobarbital, which may cause sedation and may have significant long-term effects on brain development. Recent literature has suggested that phenobarbital may be safely discontinued in some patients before discharge from the neonatal intensive care unit. Optimizing a strategy for selective early phenobarbital discontinuation would be of great value. In this study, we present a unified framework for phenobarbital discontinuation after resolution of acute symptomatic seizures in the setting of brain injury of the newborn.

Neuromonitoring in neonatal critical care part I: neonatal encephalopathy and neonates with possible seizures

The blooming of neonatal neurocritical care over the last decade reflects substantial advances in neuromonitoring and neuroprotection. The most commonly used brain monitoring tools in the neonatal intensive care unit (NICU) are amplitude integrated EEG (aEEG), full multichannel continuous EEG (cEEG), and near-infrared spectroscopy (NIRS). While some published guidelines address individual tools, there is no consensus on consistent, efficient, and beneficial use of these modalities in common NICU scenarios. This work reviews current evidence to assist decision making for best utilization of neuromonitoring modalities in neonates with encephalopathy or with possible seizures. Neuromonitoring approaches in extremely premature and critically ill neonates are discussed separately in the companion paper. IMPACT: Neuromonitoring techniques hold promise for improving neonatal care. For neonatal encephalopathy, aEEG can assist in screening for eligibility for therapeutic hypothermia, though should not be used to exclude otherwise eligible neonates. Continuous cEEG, aEEG and NIRS through rewarming can assist in prognostication. For neonates with possible seizures, cEEG is the gold standard for detection and diagnosis. If not available, aEEG as a screening tool is superior to clinical assessment alone. The use of seizure detection algorithms can help with timely seizures detection at the bedside.

Cerebral Venous Sinus Thrombosis in Preterm Infants

BACKGROUND:

Neonatal cerebral venous sinus thrombosis (CVST) can lead to brain injury and neurodevelopmental impairments. Previous studies of neonatal CVST have focused on term infants, and studies of preterm infants are lacking. In this study, we examined the clinical and radiological features, treatment and outcome of CVST in preterm infants.

METHODS:

This was a retrospective, consecutive cohort study of preterm infants (gestational age <37 weeks) with radiologically confirmed CVST. All magnetic resonance imaging/MRV and CT/CTV scans were re-reviewed to study thrombus characteristics and pattern of brain injury. Outcome was assessed by the validated pediatric stroke outcome measure at the most recent clinic visit.

RESULTS:

Twenty-six preterm infants with CVST were studied. Of these, 65% were moderate-late preterm (32–37 weeks), 27% very preterm (28–32 weeks), and 8% extreme preterm (<28 weeks). Most (73%) were symptomatic at presentation with seizures or abnormal exam. Transverse (85%) and superior sagittal (42%) sinuses were common sites of thrombosis. Parenchymal brain injury was predominantly periventricular (35%) and deep white matter (31%) in location. Intraventricular hemorrhage occurred in 46%. Most infants (69%) were treated with anticoagulation. No treated infant (including eleven with pretreatment hemorrhage) had new or worsening post-treatment hemorrhage. Outcomes ranged from no deficits (50%), mild-moderate (25%), and severe (25%) impairment.

CONCLUSIONS:

In our sample of preterm infants with CVST, more than one-quarter were asymptomatic. White matter brain lesions predominated and one-half had neurological deficits at follow-up. Anticoagulation of preterm CVST in this small cohort appeared to be safe. Larger studies of preterm CVST are needed.

Fronto-Parietal and White Matter Haemodynamics Predict Cognitive Outcome in Children with Moyamoya Independent of Stroke

Moyamoya disease is a major arteriopathy characterised by progressive steno-occlusion of the arteries of the circle of Willis. Studies in adults with moyamoya suggest an association between abnormal fronto-parietal and white matter regional haemodynamics and cognitive impairments, even in the absence of focal infarction. However, these associations have not been investigated in children with moyamoya. We examined the relationship between regional haemodynamics and ratings of intellectual ability and executive function, using hypercapnic challenge blood oxygen level-dependent magnetic resonance imaging of cerebrovascular reactivity in a consecutive cohort of children with confirmed moyamoya. Thirty children were included in the final analysis (mean age: 12.55 ± 3.03 years, 17 females, 15 idiopathic moyamoya and 15 syndromic moyamoya). Frontal haemodynamics were abnormal in all regardless of stroke history and comorbidity, but occipital lobe haemodynamics were also abnormal in children with syndromic moyamoya. Executive function deficits were noted in both idiopathic and syndromic moyamoya, whereas intellectual ability was impaired in syndromic moyamoya, even in the absence of stroke. Analysis of the relative effect of regional abnormal haemodynamics on cognitive outcomes demonstrated that executive dysfunction was predominantly explained by right parietal and white matter haemodynamics independent of stroke and comorbidity, while posterior circulation haemodynamics predicted intellectual ability. These results suggest that parietal and posterior haemodynamics play a compensatory role in overcoming frontal vulnerability and cognitive impairment.

Exploring demographic, medical, and developmental determinants of adaptive behaviour in children with hemiplegic cerebral palsy

Hemiplegic cerebral palsy (CP), the most common subtype, is characterized by high levels of mobility. Despite this, children with hemiplegic CP can face challenges functioning in and adapting to situations of everyday life. The purpose of this cross-sectional study (Hemi-NET database) was to identify factors associated with adaptive behaviour in 59 children with hemiplegic CP (ages 4-18; GMFCS I-IV). Using multivariate regression analyses, the relationship between demographic, medical, and developmental factors and adaptive behaviour (measured by the Adaptive Skills Composite score of the BASC-2) was explored. Results indicate that 34% of children had impaired adaptive skills. An autism diagnosis and lower communication functioning were significantly associated with poorer adaptive skills (R² = 0.42, F(4, 43) = 7.87, p < 0.001), while factors such as IQ scores and GMFCS level were not. The results contribute to the growing literature that suggests that clinicians and researchers need to look beyond motor functioning when working with individuals with CP.

Hemorrhagic transformation and stroke recurrence in children with cardiac disease receiving antithrombotic therapy for secondary stroke prevention

BACKGROUND

Antithrombotic therapy is currently recommended for stroke prevention in pediatric cardioembolic stroke where the recurrence risk is high; however, safety concerns remain. The primary objective of this study was to evaluate clinical and radiographic predictors of hemorrhagic transformation and stroke recurrence in children with cardiac disease to ascertain the safety and failure rates for secondary stroke prevention.

METHODS

This was a single-center, retrospective analysis of a prospectively enrolled cohort of children with radiologically confirmed cardioembolic stroke from January 2003 to December 2017 treated with institutional guidelines.

RESULTS

Eighty-two children met inclusion criteria (male 44 [54%]; neonates 23 [28%]; median age 0.43 years [0.08-4.23]). Hemorrhagic transformation occurred in 20 (24%) with the majority (75% of 20) being petechial and asymptomatic. One death (1%) was reported from hemorrhagic transformation. Four children (5%) had major extracranial hemorrhage. Most (95%) received antithrombic therapy, with anticoagulation being favored (82%). Greater stroke volume was associated with hemorrhagic transformation using the pediatric Alberta Stroke Program Early CT Score (6.1 ± 3.3 vs. 3.5 ± 2.3; p = .006). Stroke recurred in 11 (13%) children at a median 32 days (5.5-93) from the index event and the majority (90%) were on treatment at the time of recurrence. Children with univentricular physiology were less likely to have hemorrhagic transformation (RR 0.31; 95% CI 0.09-0.96, p = .04); however, they had higher rates of recurrent stroke before final palliative repair.

CONCLUSIONS

In spite of the 24% hemorrhagic transformation rate, antithrombotic therapy has a positive risk-balance in certain cardioembolic stroke subgroups, particularly in those with single-ventricle physiology, when accounting for stroke volume.

Childhood arterial ischemic stroke due to mineralizing angiopathy: an 18-year single-center experience

Mineralizing angiopathy is a unique, age-specific stroke syndrome characterized by basal ganglia infarction and lenticulostriate calcification after minor head injury in early childhood. There is limited understanding of the pathophysiology, course, and clinical outcome of this syndrome. We describe the clinical and radiographical phenotype of a single-center, consecutively enrolled cohort of children with mineralizing angiopathy from January 2002 to January 2020 and provide a comparative analysis to previously published literature. Fourteen children were identified. Previously unreported findings include: stroke onset in eight children older than 18 months; presence of basal ganglia hemorrhage in four; multifocal basal ganglia infarcts in three; presence of additional non-basal ganglia calcifications in three; and presence of thrombophilia in one. Seven children had moderate-to-severe neurological deficits. There was no symptomatic stroke recurrence (mean follow-up 3y 7mo, SD 1y 7mo). Our expanded phenotype highlights distinct characteristics of mineralizing angiopathy in children and has the potential to inform future research. What this paper adds Children with mineralizing angiopathy are often misdiagnosed as having a limb fracture despite normal x-rays. A magnetic resonance imaging-only approach may miss this entity. Non-contrast computed tomography, in addition to MRI is recommended to identify calcifications in idiopathic arterial ischemic stroke. Most children have moderate-to-severe neurological sequela.

Neurodevelopmental profiles of children with unilateral cerebral palsy associated with middle cerebral artery and periventricular venous infarctions

AIM

To compare the neurodevelopment of children with unilateral cerebral palsy (CP) with middle cerebral artery (MCA) and periventricular venous infarctions (PVIs).

METHOD

In this cross-sectional study, children with unilateral CP completed a neurological exam, unimanual Quality of Upper Extremity Skills Test, hand usage questionnaires, and IQ test. Neuroimaging was obtained from health records.

RESULTS

Two hundred and forty-five participants with unilateral CP had neuroimaging (151 [61.9%] male, ages 2-18y, median=7y 6mo, interquartile range [IQR]=6y 7mo, with 93.6% in Gross Motor Function Classification System level I/II and 78.8% in Manual Ability Classification System level I/II). Ninety-seven (39.6%) had MCA injuries and 106 (43.3%) had periventricular white matter injuries, of which 48 (45.3%) were PVIs. Median Quality of Upper Extremity Skills Test for the MCA group was 49.2 (IQR=55.8), PVI 79.9 (IQR=23.6) (Mann-Whitney U=988.50, p<0.001). Bimanual hand usage (Children's Hand-use Experience Questionnaire) (Mann-Whitney U=425, p<0.001) and light touch (odds ratio=9.12, 95% confidence interval 1.28-400.76, Fisher's exact test p=0.017) were lower in the MCA compared to the PVI group. Full-scale IQ median centile score for the MCA group was 18.0 (IQR=35.5) and 50.0 (IQR=30.0) for the PVI group (Mann-Whitney U=382, p<0.001).

INTERPRETATION

Children with unilateral CP and MCA injuries demonstrated lower hand function and usage, decreased light touch, and lower IQs compared to the PVI group. This study aids in defining rehabilitation needs informed by brain injury patterns.

Neurologic complications of pediatric congenital heart disease

Improved medical management and surgical outcomes have significantly decreased mortality in children with congenital heart disease; however, with increased survival, there is a greater lifetime exposure to neurologic complications with serious long-term neurodevelopmental consequences. Thus, recent focus has shifted to recognition and reduction of these extracardiac comorbidities. Vascular and infective complications, such as arterial ischemic stroke, infective endocarditis, and localization-related epilepsy are some of the most common neurologic comorbidities of congenital heart disease. In addition, it is now well recognized that congenital heart disease has an impact on overall brain development and contributes to adverse neurodevelopmental outcomes across multiple domains. The goal of this chapter is to summarize the most common neurologic comorbidities of congenital heart disease and its management.

Pediatric Neurology Research in the Twenty-First Century: Status, Challenges, and Future Directions Post-COVID-19

BACKGROUND

The year 2020 marked a fundamental shift in the pediatric neurology field. An impressive positive trajectory of advances in patient care and research faced sudden global disruptions by the coronavirus disease 2019 pandemic and by an international movement protesting racial, socioeconomic, and health disparities. The disruptions revealed obstacles and fragility within the pediatric neurology research mission. However, renewed commitment offers unique opportunities for the pediatric neurology research community to enhance and prioritize research directions for the coming decades.

METHODS

The Research Committee of the Child Neurology Society evaluated the challenges and opportunities facing the pediatric neurology research field, including reviewing published literature, synthesizing publically available data, and conducting a survey of pediatric neurologists.

RESULTS

We identified three priority domains for the research mission: funding levels, active guidance, and reducing disparities. Funding levels: to increase funding to match the burden of pediatric neurological disease; to tailor funding mechanisms and strategies to support clinical trial efforts unique to pediatric neurology; and to support investigators across their career trajectory. Active guidance: to optimize infrastructure and strategies, to leverage novel therapeutics, enhance data collection, and improve inclusion of children in clinical trials. Reducing disparities: to reduce health disparities in children with neurological disease, to develop proactive measures to enhance workforce diversity and inclusion, and increase avenues to balance work-life obligations for investigators.

CONCLUSIONS

In this uniquely challenging epoch, the pediatric neurology research community has a timely and important mission to re-engage the public and government, advancing the health of children with neurological conditions.

Validation of the pediatric stroke outcome measure for classifying overall neurological deficit

BACKGROUND

The pediatric stroke outcome measure (PSOM) is a standardized, disease-specific outcome measure. We aimed to validate the overall classification of neurological deficit severity using PSOM.

METHODS

We identified 367 neonates/children with arterial ischemic stroke (AIS) (Derivation Cohort). We analyzed the PSOM subscales (scored as 0 [no deficit], 0.5 [minimal/mild deficit; normal function], 1 [moderate deficit; slowing function], or 2 [severe deficit; missing function]) to derive severity levels using latent class analysis (LCA). We validated a severity classification scheme (PSOM-SCS) in: (a) children who had Pediatric Evaluation of Disability Inventory (PEDI; n = 63) and/or the Pediatric Quality-of-Life Inventory (PedsQL; n = 97) scored; and (b) an external cohort (AIS; n = 102) with concurrently scored modified Rankin Scale (mRS), King's Outcome Scale for Childhood Head-Injury (KOSCHI) and PSOM.

RESULTS

Within the Derivation Cohort, LCA identified three severity levels: "normal/mild," "moderate," and "severe" (83.7%, 13.3%, and 3%, respectively). We developed severity classification based on PSOM subscale scores: "normal/mild"-normal function in all domains or slowing in one domain, "moderate"-slowing in ≥2 domains or missing function in one domain, and "severe"-missing function in ≥2 domains or slowing in ≥1 plus missing in one domain. PEDI and PedsQL both differed significantly across the severity groups. PSOM-SCS displayed high concordance with mRS (agreement coefficient [AC2] = 0.88) and KOSCHI (AC2 = 0.79).

CONCLUSION

The PSOM-SCS constitutes a valid tool for classifying overall neurological severity emphasizing function and encompassing the full range of severity in pediatric stroke.

IMPACT

Arithmetic summing of the PSOM subscales scores to assess severity classification is inadequate.The prior severity classification using PSOM overestimates poor outcomes.Three distinct severity profiles using PSOM subscales are identified.The PSOM-SCS is in moderate to excellent agreement with other disability measures.PSOM-SCS offers a valid tool for classifying the overall neurological deficit severity.

Predicting Recovery and Outcome after Pediatric Stroke: Results from the International Pediatric Stroke Study

OBJECTIVE

To characterize predictors of recovery and outcome following pediatric arterial ischemic stroke, hypothesizing that age influences recovery after stroke.

METHODS

We studied children enrolled in the International Pediatric Stroke Study between January 1, 2003 and July 31, 2014 with 2-year follow-up after arterial ischemic stroke. Outcomes were defined at discharge by clinician grading and at 2 years by the Pediatric Stroke Outcome Measure. Demographic, clinical, and radiologic outcome predictors were examined. We defined changes in outcome from discharge to 2 years as recovery (improved outcome), emerging deficit (worse outcome), or no change.

RESULTS

Our population consisted of 587 patients, including 174 with neonatal stroke and 413 with childhood stroke, with recurrent stroke in 8.2% of childhood patients. Moderate to severe neurological impairment was present in 9.4% of neonates versus 48.8% of children at discharge compared to 8.0% versus 24.7% after 2 years. Predictors of poor outcome included age between 28 days and 1 year (compared to neonates, odds ratio [OR] = 3.58, p < 0.05), underlying chronic disorder (OR = 2.23, p < 0.05), and involvement of both small and large vascular territories (OR = 2.84, p < 0.05). Recovery patterns differed, with emerging deficits more common in children <1 year of age (p < 0.05).

INTERPRETATION

Outcomes after pediatric stroke are generally favorable, but moderate to severe neurological impairments are still common. Age between 28 days and 1 year appears to be a particularly vulnerable period. Understanding the timing and predictors of recovery will allow us to better counsel families and target therapies to improve outcomes after pediatric stroke. ANN NEUROL 2020;87:840-852.

Seizures and Outcome One Year After Neonatal and Childhood Cerebral Sinovenous Thrombosis

BACKGROUND

Pediatric cerebral sinovenous thrombosis is a treatable cause of brain injury, acute symptomatic seizures, and remote epilepsy. Our objective was to prospectively study epilepsy and outcomes in neonates and children one year after cerebral sinovenous thrombosis diagnosis.

METHODS

Patients with cerebral sinovenous thrombosis were enrolled prospectively from 21 international sites through the Seizures in Pediatric Stroke Study. Clinical data, including acute symptomatic seizures and cerebral sinovenous thrombosis risk factors, were collected at diagnosis. A neuroradiologist who was unaware of the diagnosis reviewed acute imaging. At one year, outcomes including seizure recurrence, epilepsy diagnosis, antiepileptic drug use, and modified Engel score were collected. Outcomes were assessed using the modified Rankin score and the King's Outcome Scale for Childhood Head Injury.

RESULTS

Twenty-four participants with cerebral sinovenous thrombosis were enrolled (67% male, 21% neonates). Headache was the most common presenting symptom in non-neonates (47%, nine of 19). Nine (37.5%) presented with acute symptomatic seizures. Six (25%; 95% confidence interval, 10% to 47%) developed epilepsy by one-year follow-up. No clinical predictors associated with epilepsy were identified. King's Outcome Scale for Childhood Head Injury and modified Rankin scores at one year were favorable in 71%. Half of the patients who developed epilepsy (three of six) did not have infarcts, hemorrhage, or seizures identified during the acute hospitalization.

CONCLUSION

Our study provides a prospective estimate that epilepsy occurs in approximately one-quarter of patients by one year after diagnosis of cerebral sinovenous thrombosis. Later epilepsy can develop in the absence of acute seizures or parenchymal injury associated with the acute presentation.

Obstructive sleep apnea syndrome and neuropsychological function in pediatric stroke

OBJECTIVES

To assess the prevalence of obstructive sleep apnea syndrome (OSAS) in children with arterial ischemic stroke (AIS) and to evaluate its association with neuropsychological outcomes.

METHODS

We conducted a cross-sectional study of sleep health and neuropsychological outcome in children with AIS. A consecutive cohort of children attending a stroke clinic were assessed using a standardized pediatric sleep questionnaire (PSQ) and standardized measures of pediatric stroke outcome and intellectual, executive and adaptive function. High risk for OSAS was defined as PSQ score ≥0.33.

RESULTS

Overall, 102 children were included (55% males, median age: 9 years [interquartile-range [IQR]: 6-14]). The prevalence of OSAS in children with AIS was significantly higher compared to published normative prevalence rate (25.5% vs 5%, p < 0.001). Children with OSAS were more likely to have infarcts affecting both the anterior and posterior circulation (37.5% vs 9.5%, p = 0.021). In addition, children with OSAS had significantly higher median Pediatric Stroke Outcome Measure (PSOM) scores (2 [IQR: 0-2] vs 1 [IQR: 1-3.5], p = 0.01) and were more likely to be prescribed concomitant medications affecting sleep architecture (50% vs 22.4%, p = 0.007). OSAS was associated with significantly lower scores on intellectual, memory, cognitive, behavioral, attention, executive and adaptive function scales. The association between PSQ and intellectual ability and working memory remained statistically significant upon controlling for potential confounding factors including stroke related characteristics (neurologic impairment and arterial territory).

CONCLUSIONS

The prevalence of OSAS in children with AIS compared to healthy controls is significantly elevated and is associated with poor neuropsychological outcomes. We highlight the importance of regular screening for OSAS - a modifiable risk factor - in children with AIS. The specific risk factors for OSAS and the potential benefits of therapeutic interventions in this patient population warrant further investigation.

Abstract TP361: Recreational Drug Use and Arterial Ischemic Stroke in a Pediatric Cohort

Background: Existing literature reports an association between recreational drug use and arterial ischemic stroke (AIS) in adults. Due to recent trends in legalization and concerns regarding the impact of drugs on the developing brain, there is an urgent need for increased awareness of recreational drug use as a risk factor for AIS in childhood.

Purpose: To increase awareness of an association between AIS and recreational drug use in a pediatric cohort.

Methods: We conducted a retrospective chart review of a consecutive cohort of patients at a tertiary care pediatric center diagnosed with AIS in the context of recreational drug use between 2008-2017. Drug use was confirmed using toxicology testing and clinical history. Demographic, clinical and radiological data were collected. Pediatric Stroke Outcome Measure scores (PSOM) were obtained from an institutional Stroke Registry.

Results: Three males and one female were included in the study. Mean age at stroke presentation was 16.3 years (range 16-17 years). Three children presented with focal neurologic deficit and one with new onset seizure. Drug use for each patient was described as follows: Patient A - Marijuana; Patient B - Oxybutynin, Fluoxetine and unidentified compound; Patient C - Marijuana and Amphetamine; Patient D - Marijuana and alcohol. MRI demonstrated diffusion restriction in the anterior circulation in two children, anterior and posterior circulation in one child, and bilateral posterior circulation in one child also found to have a remote AIS. Vascular findings included: Patient A - normal; Patient B and C - right anterior circulation arteriopathy; Patient D - posterior circulation arteriopathy and bilateral vessel wall enhancement. ECHO and pro-thrombotic results were non-contributory. However, one patient required PFO closure. PSOM scores indicated mild-moderate disability initially and moderate disability at follow-up for three of four patients.

Conclusions: This case series describes an association between recreational drug use and AIS in adolescents. We are unable to comment on the incidence of AIS related to drug use from our cohort. However, our data highlights a need for public health strategies that acknowledge AIS as a potential consequence of recreational drug use in adolescents.

Abstract TMP110: Antithrombotic Therapy and Risk of Stroke Recurrence in Children With Congenital and Acquired Cardiac Disease

Background: Antithrombotic therapy (ATT) is currently recommended for stroke prevention in pediatric cardioembolic arterial ischemic stroke (CE-AIS) where the risk of recurrence is high.

Methods: We conducted a retrospective study of a prospectively enrolled cohort of neonates and children with radiologically-confirmed cardioembolic arterial ischemic stroke (CE-AIS) from January 2003 - December 2017. We evaluated the clinical and radiographic predictors of hemorrhagic transformation (HT) and stroke recurrence to assess the safety and efficacy of ATT.

Results: Eighty-two children met inclusion criteria [53.7% males and 28% neonates; median age 0.43 (IQR: 0.08 - 4.23) years]. Stroke recurred in 11 children at a median of 32 days (IQR: 5.5 - 93) from the index event. Most recurrent infarcts were silent (n=6; 54.5%) and found on follow-up neuroimaging with an average follow-up interval of 4.1 ±3 .5 years. Procedure-related recurrence took place in 1 (9.1%) child. Ten (90.9%) children were receiving antithrombotic therapy at the time of recurrence: 8 (72.7%) were on anticoagulant therapy (ACT) and 2 (18.2%) were on a combination of antiplatelet (ATP) and ACT. HT occurred in 20 of 82 children (24.4%), all of whom were receiving ACT, 5 (6.1%) of whom were symptomatic. Four (4.9%) had systemic hemorrhage. There was no difference in the frequency of stroke recurrence between those with and without HT [3 (15.0%) vs. 8 (12.9%); p=1.00]. Children with univentricular physiology were less likely to have HT [15% vs. 43.5%; p=0.03] and had higher rates of recurrent stroke, prior to definitive cardiac repair, despite receiving ATT. Stroke recurrence was highest in those with cyanotic congenital heart disease (CHD) pre-surgery (3/11), cyanotic CHD post-palliative surgery with residual right-to-left-shunt (3/11) and in those with cardiomyopathy (4/11). HT was not associated with ATP vs. ACT use nor combination therapy.

Conclusion: ATT appears to be relatively safe in children with CE-AIS. However, ATT warrants further optimization to prevent stroke recurrence, particularly in those with single ventricle physiology and reduced left ventricular function.

Additional validation study and French cross-cultural adaptation of the Pediatric Stroke Outcome Measure-Summary of Impressions (PSOM-SOI)

BACKGROUND

The Pediatric Stroke Outcome Measure-Summary of Impressions (PSOM-SOI) measures neurological function across right and left sensorimotor domains (Item A), language production (Item B), language comprehension (Item C), and cognition/behaviour (Item D).

OBJECTIVE

This study was a cross-cultural adaptation into French of the PSOM-SOI and an assessment of its reliability and limitations of use.

MATERIAL AND METHODS

The translation and adaptation of the PSOM-SOI was followed by the assessment of its reliability in a cohort of 69 children with diagnosed acute neonatal arterial ischemic stroke. Three independent raters retrospectively scored the PSOM-SOI based on data from in-person neurological examination and results of standardized tests performed at age 7 in the cohort database. Comparison 1 (C1) involved a less experienced rater and an experienced rater and comparison 2 (C2) involved 2 experienced raters. Inter-rater reliability (IRR) was measured with Kappa coefficients.

RESULTS

The cross-cultural adaptation was easily performed, and no rater had difficulties using the French PSOM-SOI. The IRR was better in C1 than C2. For Item A, the agreement in C1 (κ=0.47) and C2 (κ=0.44) was moderate. The C1 agreement was substantial for Items B (κ=0.71) and C (κ=0.70); the C2 agreement was fair for Item B (κ=0.23) and slight for Item C (κ=0.16). For Item D, the agreement was moderate in C1 (κ=0.52) and fair in C2 (κ=0.35). In all but one comparison, agreement or minor disagreement (≤0.5 points) was obtained for more than 90% of the item scores. Regarding the total score, agreement for normal function (≤0.5) versus abnormal function (>0.5) was achieved for 90% in C1 and 67% in C2.

CONCLUSION

The IRR of the French PSOM-SOI gave variable results depending on the item and rater's experience, but the extent of disagreements was minor for individual items and total score. Additional prospective validation studies using the French PSOM-Short Neurological Exam to score the PSOM-SOI are needed. A dichotomised total score (cut-off≤0.5) could be used to define normal function versus poor outcome.

Predicting Ischemic Risk Using Blood Oxygen Level-Dependent MRI in Children with Moyamoya

BACKGROUND AND PURPOSE

Moyamoya is a progressive steno-occlusive arteriopathy. MR imaging assessment of cerebrovascular reactivity can be performed by measuring the blood oxygen level-dependent cerebrovascular reactivity response to vasoactive stimuli. Our objective was to determine whether negative blood oxygen level-dependent cerebrovascular reactivity status is predictive of ischemic events in childhood moyamoya.

MATERIALS AND METHODS

We conducted a retrospective study of a consecutive cohort of children with moyamoya who underwent assessment of blood oxygen level-dependent cerebrovascular reactivity. The charts of patients with written informed consent were reviewed for the occurrence of arterial ischemic stroke, transient ischemic attack, or silent infarcts. We used logistic regression to calculate the OR and 95% CI for ischemic events based on steal status. Hazard ratios for ischemic events based on age at blood oxygen level-dependent cerebrovascular reactivity imaging, sex, and moyamoya etiology were calculated using Cox hazards models.

RESULTS

Thirty-seven children (21 female; median age, 10.7 years; interquartile range, 7.5-14.7 years) were followed for a median of 28.8 months (interquartile range, 13.7-84.1 months). Eleven (30%) had ischemic events, 82% of which were TIA without infarcts. Steal was present in 15 of 16 (93.8%) hemispheres in which ischemic events occurred versus 25 of 58 (43.1%) ischemic-free hemispheres (OR = 19.8; 95% CI, 2.5-160; P = .005). Children with idiopathic moyamoya were at significantly greater risk of ischemic events (hazard ratio, 3.71; 95% CI, 1.1-12.8; P = .037).

CONCLUSIONS

Our study demonstrates that idiopathic moyamoya and the presence of steal are independently associated with ischemic events. The use of blood oxygen level-dependent cerebrovascular reactivity could potentially assist in the selection of patients for revascularization surgery and the direction of therapy in children with moyamoya.

Arterial Ischemic Stroke Secondary to Cardiac Disease in Neonates and Children

OBJECTIVE

We describe the risk factors for peri-procedural and spontaneous arterial ischemic stroke (AIS) in children with cardiac disease.

METHODS

We identified children with cardiac causes of AIS enrolled in the International Pediatric Stroke Study registry from January 2003 to July 2014. Isolated patent foramen ovale was excluded. Peri-procedural AIS (those occurring during or within 72 hours of cardiac surgery, cardiac catheterization, or mechanical circulatory support) and spontaneous AIS that occurred outside of these time periods were compared.

RESULTS

We identified 672 patients with congenital or acquired cardiac disease as the primary risk factor for AIS. Among these, 177 patients (26%) had peri-procedural AIS and 495 patients (74%) had spontaneous AIS. Among non-neonates, spontaneous AIS occurred at older ages (median 4.2 years, interquartile range 0.97 to 12.4) compared with peri-procedural AIS (median 2.4 years, interquartile range 0.35 to 6.1, P < 0.001). About a third of patients in both groups had a systemic illness at the time of AIS. Patients who had spontaneous AIS were more likely to have a preceding thrombotic event (16 % versus 9 %, P = 0.02) and to have a moderate or severe neurological deficit at discharge (67% versus 33%, P = 0.01) compared to those with peri-procedural AIS.

CONCLUSIONS

Children with cardiac disease are at risk for AIS at the time of cardiac procedures but also outside of the immediate 72 hours after procedures. Many have acute systemic illness or thrombotic event preceding AIS, suggesting that inflammatory or prothrombotic conditions could act as a stroke trigger in this susceptible population.

Abstract WMP120: The Role of Age, Lesion Location and Volume in Predicting Long-Term Neurological Outcomes in Pediatric Ischemic Stroke

Introduction: The balance of plasticity versus vulnerability to acute ischemic injury in the immature brain across development remains controversial. We aimed to investigate the relationship between age at stroke and lesion location and volume with long-term outcomes following arterial ischaemic stroke (AIS).

Hypothesis: Age at stroke onset interacts with lesion location and volume to predict long-term neurological outcomes.

Methods: In a single-centre prospective study, children aged term birth to 18 years with acute symptomatic AIS from 1992 to 2016 who underwent neuroimaging (CT/MRI) within 14 days of stroke onset were studied. Long term outcomes were assessed with the Pediatric Stroke Outcome Measure (PSOM). Outcomes were defined as normal (score 0-0.5 on 1-5 PSOM subscales), otherwise abnormal. AIS lesions were classified based on major (anterior, middle, posterior, other) cerebral arteries and branch sub-territories (e.g. MCA-lateral lenticulostriate). For each vascular territory, the proportion of infarcted brain was estimated as ‘small’ (≤50% territory) or ‘large’ (>50% territory). Factors predictive of long term outcomes were evaluated using logistic regression models.

Results: Among 285 children, median age at stroke onset was 22 months (IQR: 0.03-101), 41% were females. PSOM scoring at median 9 years (IQR: 4-15) post-stroke was normal in 61%. Abnormal outcome was associated with age 1-4 years (OR=2.2, 95% CI: 1.02-4.9), ‘large’ proportion infarcts involving cortex within any major artery territory (OR=6.1, 95% CI: 2.6-14.4), and subcortical infarcts: OR= 2.7 (95% CI: 1.4-5.4) for small proportion infarcts; OR=8.3 (95% CI: 4.2-16.6) for large proportion infarcts in either medial or lateral lenticulostriate arteries; OR=15.8 (95% CI: 5-50.3) for large volume lesions in both lenticulostriate territories. In multivariate logistic regression, age, cortical and subcortical infarcts predicted long-term neurologic outcomes.

Conclusions: In addition to age at stroke onset, infarct location including volume plays a key role in predicting long-term neurological outcomes in children. While the relationship between age and neurological outcomes seems to be bimodal, a linear effect of lesion volume on stroke outcomes is evident.

Recurrent stroke: the role of thrombophilia in a large international pediatric stroke population

Risk factors for arterial ischemic stroke in children include vasculopathy and prothrombotic risk factors but their relative importance to recurrent stroke is uncertain. Data on recurrent stroke from databases held in Canada (Toronto), Germany (Kiel-Lübeck/Münster), and the UK (London/Southampton) were pooled. Data were available from 894 patients aged 1 month to 18 years at first stroke (median age, 6 years) with a median follow-up of 35 months. Among these 894 patients, 160 (17.9%) had a recurrence between 1 day and 136 months after the first stroke (median, 3.1 months). Among 288 children with vasculopathy, recurrence was significantly more common [hazard ratio (HR) 2.5, 95% confidence interval (95% CI) 1.92-3.5] compared to the rate in children without vasculopathy. Adjusting for vasculopathy, isolated antithrombin deficiency (HR 3.9; 95% CI: 1.4-10.9), isolated elevated lipoprotein (a) (HR 2.3; 95% CI: 1.3-4.1), and the presence of more than one prothrombotic risk factor (HR 1.9; 95% CI: 1.12-3.2) were independently associated with an increased risk of recurrence. Recurrence rates calculated per 100 person-years were 10 (95% CI: 3-24) for antithrombin deficiency, 6 (95% CI: 4-9) for elevated lipoprotein (a), and 13 (95% CI: 7-20) for the presence of more than one prothrombotic risk factor. Identifying children at increased risk of a second stroke is important in order to intensify measures aimed at preventing such recurrences.

Incidence and Current Treatment Gaps in Pediatric Stroke and TIA: An Ontario-Wide Population-Based Study

BACKGROUND

Reported incidence rates of pediatric stroke and transient ischemic attack (TIA) range widely. Treatment gaps are poorly characterized. We sought to evaluate in -Ontario, the incidence and characteristics of pediatric stroke and TIA including care gaps and the predictive value of International Classification of Diseases (ICD) codes.

METHODS

A retrospective chart review was conducted at 147 Ontario pediatric and adult acute care hospitals. Pediatric stroke and TIA cases (age < 18 years) were identified using ICD-10 code searches in the 2010/11 Canadian Institute for Health Information's Discharge Abstract Database (CIHI-DAD) and National Ambulatory Care Reporting System (NACRS) databases in the Ontario Stroke Audit.

RESULTS

Among 478 potential pediatric stroke and TIA cases identified in the CIHI-DAD and NACRS databases, 163 were confirmed as cases of stroke and TIA during the 1-year study period. The Ontario stroke and TIA incidence rate was 5.9 per 100,000 children (3.3 ischemic, 1.8 hemorrhagic and 0.8 TIA). Mean age was 6.4 years (16% neonate). Nearly half were not imaged within 24 h of arrival in emergency and only 56% were given antithrombotic treatment. At discharge, 83 out of 121 (69%) required health care services post-discharge. Overall positive predictive value (PPV) of ICD-10 stroke and TIA codes was 31% (range 5-74%) and yield ranged from 2.4 to 29% for acute stroke or TIA event; code I63 achieved maximal PPV and yield.

CONCLUSION

Our population-based study yielded a higher incidence rate than prior North-American studies. Important care gaps exist including delayed diagnosis, lack of expert care, and departure from published treatment guidelines. Variability in ICD PPV and yield underlines the need for prospective data collection and for improving the pediatric stroke and TIA coding processes.

Anatomical Venous Variants in Children With Cerebral Sinovenous Thrombosis

Background and Purpose- Literature is sparse on the frequency and significance of anatomical venous variants (AVVs) in pediatric cerebral sinovenous thrombosis (CSVT). Methods- We retrospectively reviewed children with CSVT and controls undergoing computed tomography/magnetic resonance venography from January 2008 to 2014. Clinical features examined included raised intracranial pressure, risk factors, and treatment. Radiological features examined included CSVT location, presence and type of AVVs, hemorrhagic venous infarction, and venous collateralization. Clinical outcome was measured by the pediatric stroke outcome measure and radiological outcome by thrombus recanalization. Results- Fifty-one children with CSVT were identified. Twenty-two (43%) had AVVs at presentation. Nineteen (86%) had hypoplasia/absence of major dural sinus, 5 (23%) had persistent fetal structures, 3 (14%) had duplications/fenestrations, and 1 (5%) had disconnected superficial and deep venous systems. Controls had a slightly higher but nonsignificant prevalence 26 (51%) of AVVs. No significant clinical and radiological differences were observed between children with CSVT and AVVs compared with those with typical venous anatomy. Conclusions- AVVs are seen in many children with and without CSVT and do not seem to alter the presentation or clinical course. The influence of these variations on the brain's ability to tolerate venous congestion because of thrombosis merits further study.

Global, Regional, and Country-Specific Lifetime Risks of Stroke, 1990 and 2016

BACKGROUND

The lifetime risk of stroke has been calculated in a limited number of selected populations. We sought to estimate the lifetime risk of stroke at the regional, country, and global level using data from a comprehensive study of the prevalence of major diseases.

METHODS

We used the Global Burden of Disease (GBD) Study 2016 estimates of stroke incidence and the competing risks of death from any cause other than stroke to calculate the cumulative lifetime risks of first stroke, ischemic stroke, or hemorrhagic stroke among adults 25 years of age or older. Estimates of the lifetime risks in the years 1990 and 2016 were compared. Countries were categorized into quintiles of the sociodemographic index (SDI) used in the GBD Study, and the risks were compared across quintiles. Comparisons were made with the use of point estimates and uncertainty intervals representing the 2.5th and 97.5th percentiles around the estimate.

RESULTS

The estimated global lifetime risk of stroke from the age of 25 years onward was 24.9% (95% uncertainty interval, 23.5 to 26.2); the risk among men was 24.7% (95% uncertainty interval, 23.3 to 26.0), and the risk among women was 25.1% (95% uncertainty interval, 23.7 to 26.5). The risk of ischemic stroke was 18.3%, and the risk of hemorrhagic stroke was 8.2%. In high-SDI, high-middle-SDI, and low-SDI countries, the estimated lifetime risk of stroke was 23.5%, 31.1% (highest risk), and 13.2% (lowest risk), respectively; the 95% uncertainty intervals did not overlap between these categories. The highest estimated lifetime risks of stroke according to GBD region were in East Asia (38.8%), Central Europe (31.7%), and Eastern Europe (31.6%), and the lowest risk was in eastern sub-Saharan Africa (11.8%). The mean global lifetime risk of stroke increased from 22.8% in 1990 to 24.9% in 2016, a relative increase of 8.9% (95% uncertainty interval, 6.2 to 11.5); the competing risk of death from any cause other than stroke was considered in this calculation.

CONCLUSIONS

In 2016, the global lifetime risk of stroke from the age of 25 years onward was approximately 25% among both men and women. There was geographic variation in the lifetime risk of stroke, with the highest risks in East Asia, Central Europe, and Eastern Europe. (Funded by the Bill and Melinda Gates Foundation.).

Predictors of Cognitive and Academic Outcome following Childhood Subcortical Stroke

Childhood arterial ischemic stroke often involves basal ganglia and thalamus but little is known about neuropsychological outcomes in this group. We examined intellectual ability, academics, attention, executive function, and psychological diagnoses in children and adolescents (6-20 years of age) with childhood stroke involving the basal ganglia (n = 32) or thalamus (n = 12). Intellectual ability was age-appropriate but working memory was significantly lower than expected. Compared to the normative mean, the stroke group exhibited significantly weaker performance in reading comprehension, math fluency, attention, and greater challenges with executive function. Children with basal ganglia stroke had weaker working memory and were more likely to receive diagnoses of Attention Deficit Hyperactivity Disorder and Anxiety Disorder than those with thalamic stroke. Lesion size was most important in predicting working memory ability, whereas age at stroke and age at test were important in predicting academic ability.

Breath-Hold Blood Oxygen Level-Dependent MRI: A Tool for the Assessment of Cerebrovascular Reserve in Children with Moyamoya Disease

BACKGROUND AND PURPOSE

There is a critical need for a reliable and clinically feasible imaging technique that can enable prognostication and selection for revascularization surgery in children with Moyamoya disease. Blood oxygen level-dependent MR imaging assessment of cerebrovascular reactivity, using voluntary breath-hold hypercapnic challenge, is one such simple technique. However, its repeatability and reliability in children with Moyamoya disease are unknown. The current study sought to address this limitation.

MATERIALS AND METHODS

Children with Moyamoya disease underwent dual breath-hold hypercapnic challenge blood oxygen level-dependent MR imaging of cerebrovascular reactivity in the same MR imaging session. Within-day, within-subject repeatability of cerebrovascular reactivity estimates, derived from the blood oxygen level-dependent signal, was computed. Estimates were associated with demographics and intellectual function. Interrater reliability of a qualitative and clinically applicable scoring scheme was assessed.

RESULTS

Twenty children (11 males; 12.1 ± 3.3 years) with 30 MR imaging sessions (60 MR imaging scans) were included. Repeatability was "good" on the basis of the intraclass correlation coefficient (0.70 ± 0.19). Agreement of qualitative scores was "substantial" (κ = 0.711), and intrarater reliability of scores was "almost perfect" (κ = 0.83 and 1). Younger participants exhibited lower repeatability (P = .027). Repeatability was not associated with cognitive function (P > .05). However, abnormal cerebrovascular reactivity was associated with slower processing speed (P = .015).

CONCLUSIONS

Breath-hold hypercapnic challenge blood oxygen level-dependent MR imaging is a repeatable technique for the assessment of cerebrovascular reactivity in children with Moyamoya disease and is reliably interpretable for use in clinical practice. Standardization of such protocols will allow further research into its application for the assessment of ischemic risk in childhood cerebrovascular disease.

Children with post-stroke epilepsy have poorer outcomes one year after stroke

Background Epilepsy is a common complication of pediatric stroke. Aim In this study, we aim to measure the association between epilepsy and neurologic outcome after childhood arterial ischemic stroke. Methods Prospective cohort study of children (29 days-19 years) enrolled after an acute arterial ischemic stroke at 21 international pediatric stroke centers and followed to identify epilepsy. One year post-stroke, outcomes were scored using the examination-based Pediatric Stroke Outcome Measure (range = 0-10); higher values reflect greater disability. Ordinal logistic regression was used to measure the association of Pediatric Stroke Outcome Measure scores (categorized as 0-1, 1.5-3, 3.5-6, 6.5-10) with epilepsy. Results Investigators enrolled 86 children (median age = 6.1 years, interquartile range (IQR) = 1.4-12.2 years) with acute stroke. At 1 year, 18/80 (23%) remained on an anticonvulsant including 8/80 (10%) with epilepsy. Among the 70 with Pediatric Stroke Outcome Measure scored, the median was 0.5 (IQR = 0-1.5) for children without epilepsy ( n = 63), and 6 (IQR = 0.5-10) for children with epilepsy ( n = 7). In univariable analyses, poorer 1-year outcome was associated with middle cerebral artery stroke, cortical infarcts, hemorrhagic transformation, hospital disposition not to home, and epilepsy. In multivariable analysis, middle cerebral artery stroke (odds ratio (OR) = 4.9, 95% confidence intervals (CI) = 1.1-21.3) and epilepsy (OR = 24.1, CI = 1.5-380) remained associated with poorer outcome. Conclusions Children who developed epilepsy during the first year post-stroke had poorer neurologic outcomes than those without epilepsy.

Mortality After Pediatric Arterial Ischemic Stroke

OBJECTIVES

Cerebrovascular disease is among the top 10 causes of death in US children, but risk factors for mortality are poorly understood. Within an international registry, we identify predictors of in-hospital mortality after pediatric arterial ischemic stroke (AIS).

METHODS

Neonates (0-28 days) and children (29 days-<19 years) with AIS were enrolled from January 2003 to July 2014 in a multinational stroke registry. Death during hospitalization and cause of death were ascertained from medical records. Logistic regression was used to analyze associations between risk factors and in-hospital mortality.

RESULTS

Fourteen of 915 neonates (1.5%) and 70 of 2273 children (3.1%) died during hospitalization. Of 48 cases with reported causes of death, 31 (64.6%) were stroke-related, with remaining deaths attributed to medical disease. In multivariable analysis, congenital heart disease (odds ratio [OR]: 3.88; 95% confidence interval [CI]: 1.23-12.29; P = .021), posterior plus anterior circulation stroke (OR: 5.36; 95% CI: 1.70-16.85; P = .004), and stroke presentation without seizures (OR: 3.95; 95% CI: 1.26-12.37; P = .019) were associated with in-hospital mortality for neonates. Hispanic ethnicity (OR: 3.12; 95% CI: 1.56-6.24; P = .001), congenital heart disease (OR: 3.14; 95% CI: 1.75-5.61; P < .001), and posterior plus anterior circulation stroke (OR: 2.71; 95% CI: 1.40-5.25; P = .003) were associated with in-hospital mortality for children.

CONCLUSIONS

In-hospital mortality occurred in 2.6% of pediatric AIS cases. Most deaths were attributable to stroke. Risk factors for in-hospital mortality included congenital heart disease and posterior plus anterior circulation stroke. Presentation without seizures and Hispanic ethnicity were also associated with mortality for neonates and children, respectively. Awareness and study of risk factors for mortality represent opportunities to increase survival.

Abstract 19: Clinical and Neuroimaging Profile of Children With Arterial Ischemic Stroke Due to Cerebral Arteriopathy - Results From the International Pediatric Stroke Study (IPSS)

Introduction: Cerebral arteriopathies are frequently identified in children with arterial ischemic stroke (AIS), and are distinguished by high stroke recurrence. However, the clinical and neuroimaging profiles of AIS due to cerebral arteriopathy versus non- arteriopathy have not been compared.

Hypothesis: We hypothesized that children with AIS due to arteriopathy would differ in their demographic, clinical, and radiographic presentation from those without arteriopathy.

Methods: We report a large, prospective, multicentre cohort of children, 1 month - 17 years, with AIS, enrolled in the International Pediatric Stroke Study, 2003-2014. Those with arteriopathy including focal cerebral arteriopathy, dissection, moyamoya, vasculitis and non-specific arteriopathies, were compared to those with non-arteriopathic stroke etiologies.

Results: Of 2127 children with AIS, 725(34%) had arteriopathy (58% male, mean age 8.1years). The remaining 1402(66%) had non-arteriopathic AIS. Arteriopathy was associated with older age, but not a specific gender or ethnicity. Geographic differences were observed. Children with arteriopathy were likely to present with hemiparesis, dysarthria, ataxia, headache, preceding/concurrent thromboembolic events and without seizures. Risk factors associated with arteriopathy included sickle anemia, head/neck trauma and lack of acute systemic disease. Radiological associations with arteriopathy included right sided unilateral or bilateral stroke, multiple infarcts and relative reduction in occurrence of intracranial hemorrhage. On multivariate analysis, headache (p=0.006), additional thromboembolic events (p=0.007), multiple infarcts (p=0.002) and lack of seizures (p=0.001) were independently associated with arteriopathy.

Conclusions: Specific clinical profiles are associated with arteriopathy in children with AIS and may guide the clinician in early diagnostic evaluations and management.

Abstract TMP102: Predicting Recovery and Outcome After Pediatric Stroke

We aimed to characterize the timing of recovery and predictors of outcome following pediatric stroke, with the hypothesis that the recovery pattern after stroke is influenced by age. While the immature brain is often presumed to have an increased capacity for neuroplasticity, there is little direct data examining how recovery differs in children of different ages. We reviewed data for children with arterial ischemic stroke (AIS) who were enrolled in the International Pediatric Stroke Study, a prospective registry of children with stroke. Inclusion criteria included a diagnosis of AIS and the availability of outcome at two years after the index stroke event. A subset of these patients who had multiple assessments over time were used to study longitudinal patterns of recovery. We investigated demographic, clinical, and radiologic associations with both early outcome at discharge and long term outcome at two years using multinomial logistic regression. Categorical outcomes at each timepoint were defined by Pediatric Stroke Outcome Measure (PSOM). We studied longitudinal recovery using time-to-event (survival) analysis. 614 out of 4,294 patients met our inclusion criteria. 202 patients had perinatal AIS while 412 had childhood AIS. Perinatal AIS was associated with significant worsening between discharge and two years, as neurologic impairment became more apparent, but with better outcomes at both timepoints compared with childhood AIS (moderate/severe: 14% vs 49% at discharge, 47% vs 54% at 2 years). Predictors of severe deficits in univariate analyses included age at stroke (perinatal vs. childhood), hemiparesis or decreased consciousness at presentation, anterior circulation, and large vessel involvement. In longitudinal analysis, improvement in PSOM occurred for a longer time after stroke onset in younger children compared to older children. Although age has a strong influence on recovery after pediatric stroke, all children had the capacity to demonstrate recovery over extended periods of time. Understanding the timing and predictors of recovery will allow us to better target therapies to the appropriate windows of opportunity, thereby improving outcomes after pediatric stroke.

Abstract 15: Mortality After Pediatric Arterial Ischemic Stroke: Results From the International Paediatric Stroke Study

Introduction: Stroke is reported among the top 10 causes of death in children in the US. In the Kids’ Inpatient Database, older age and Hispanic ethnicity were risk factors for mortality after pediatric ICH. Limited data is available regarding risk factors for death after pediatric arterial ischemic stroke (AIS).

Objective: To identify predictors of in-hospital mortality in pediatric patients hospitalized with AIS.

Methods: Neonates (0-28 days) and children (29 days- <19 years) with AIS were enrolled from 1/2003 to 7/2014 in the IPSS multinational stroke registry. Death prior to hospital discharge and cause of death was ascertained from medical records. Logistic regression was used to analyze associations between risk factors and in-hospital mortality.

Results: Fourteen of 915 neonates (1.5%) and 74/2,285 children (3.2%) died during hospitalization. Of 54 cases with reported causes of death, 32 (59%) were related to AIS (herniation 2, brain death 10, ICH/hemorrhagic transformation 5, care withdrawal due to stroke severity 15), with the remaining deaths attributed to underlying medical disease. Of 356 children with Pediatric NIH Stroke Scale (PedNIHSS) scores, median PedNIHSS was 19 (IQR 14-27) among the 13 children who died and 7 (IQR 3-12) among the 343 children who did not die. In multivariable analysis, congenital heart disease (OR 4.1, 95%CI 1.3-13, p=0.018) and posterior plus anterior circulation stroke (OR 4.3, 95%CI 1.3-14, p=0.017) were associated with in-hospital mortality for neonates, while higher PedNIHSS [OR 1.11 (per 1 point PedNIHSS increase), 95%CI 1.03-1.19, p=0.004], Hispanic ethnicity (OR 7.6, 95%CI 1.8-32.3, p=0.006), and cardiac disease (OR 7.5, 95%CI 1.5-38.6, p=0.015) were associated with in-hospital mortality for children.

Conclusions: In-hospital mortality occurred in about 2% of pediatric AIS cases with nearly 60% attributable to stroke. Risk factors for in-hospital mortality included cardiac disease and stroke severity, factors also associated with mortality in adults. Hispanic ethnicity, a factor associated with mortality in childhood ICH, was also associated with mortality after childhood AIS; the underlying reasons are unclear. Additional information is needed on stroke-related deaths after hospitalization.

Abstract 18: Anticonvulsant Medication Practice Varies After Pediatric Arterial Ischemic Stroke

Introduction: Acute symptomatic seizures are common after pediatric arterial ischemic stroke (AIS). We sought to analyze practice variation in anticonvulsant medication treatment (ACM) after AIS. We hypothesized that ACM practice varies but is related to age, acute seizure frequency and duration, cortical involvement, and hemorrhagic conversion.

Methods: Seizures in Pediatric Stroke (SIPS), an international, prospective study, enrolled neonatal (<28 days) and childhood (<19 years) acute AIS patients 3/2011-8/2012. Seizures and ACM were recorded. Among patients with acute seizures (<7 days post-stroke), we used univariate Spearman’s correlations to determine association between ACM and clinical predictors at both discharge and 12-month time points. Variables with p <0.05 at univariate analysis were entered into a logistic regression model.

Results: Among 116 patients, 27 neonates and 31 children (ages 0.2-17 years) had an acute seizure. In neonates, 24 (89%) had ACM continued after discharge, but only 4 (15%) remained on ACM at 12 m (3 having had post-discharge seizure). Phenobarbital was the most common ACM in neonates at discharge (n=14) and 12m (n=2, levetiracetam = 2). In children, 23 (74%) had ACM at discharge, and 17 (57%) remained on ACM at 12m (7 having had a post-discharge seizure). All patients in study with post-discharge seizure were discharged on ACM. Two neonates and 1 child with post-discharge seizure were not on ACM at 12m. Levetiracetam was the most common ACM in children at discharge (n=11) and 12m (n=9). No single variable correlated with discharge ACM (Table). ACM at 12 m correlated with neonatal stroke, >10 seizures in acute period, and post-discharge seizure. In logistic regression, all variables remained significant.

Conclusion: ACM management after acute post-stroke seizures varies widely in pediatric stroke. Neonates rarely, but children frequently, are continued on ACM up to 1 year, even without further seizures.

Paediatric stroke

The past decade has seen a dramatic increase in pediatric stroke research. However few studies have addressed anti-thrombotic safety or effectiveness. Three paediatric stroke guidelines combining research data with expert consensus have been published in the past five years. For most patients treatment recommendations are consistent. Newborns with arterial ischaemic stroke (AIS) rarely require antithrombotic treatment given their extremely low risk of recurrence. In children with AIS a substantial recurrence risk means that antithrombotic treatment is required unless contraindicated. Anticoagulation (heparins, warfarin) is recommended for possible or established dissection and cardiogenic embolism. Antiplatelet treatment is recommended for other children with AIS. For neonatal cerebral sinovenous thrombosis (CSVT) most centers provide initial anticoagulation in the absence of haemorrhagic contra indications, and otherwise, monitor for propagation. Children with CSVT, even with haemorrhagic infarction, more consistently receive anticoagulation, as in adults. While more studies are necessary, current treatment guidelines offer an interim option for guiding the treatment of paediatric stroke.

Moyamoya Disease in Children: Results From the International Pediatric Stroke Study

This study aimed to describe children with moyamoya disease from an international multicenter stroke database, and explore risk factors for stroke recurrence. We reviewed data of children >28-days old with moyamoya disease enrolled in the International Pediatric Stroke Study from January 2003 to March 2013. A total of 174 children from 32 sites and 14 countries had moyamoya disease; median age 7.4 years, 49% male. Of these, 90% presented with ischemic stroke, 7.5% with transient ischemic attack, and 2.5% with hemorrhagic stroke. One-third of patients had moyamoya syndrome. Stroke recurrence was 20% over median follow-up of 13 months; 9% had multiple recurrences. Children treated with surgical revascularization were less likely to have stroke recurrence ( P = .046). Moyamoya disease accounted for 8% of arterial strokes in this international pediatric stroke registry. One-third of pediatric patients with moyamoya disease have an underlying syndromic condition. Surgical revascularization is effective at reducing the incidence of stroke recurrence.

Strategies to Improve Stroke Care Services in Low- and Middle-Income Countries: A Systematic Review

Background: The burden of stroke in low- and middle-income countries (LMICs) is large and increasing, challenging the already stretched health-care services. Aims and Objectives: To determine the quality of existing stroke-care services in LMICs and to highlight indigenous, inexpensive, evidence-based implementable strategies being used in stroke-care. Methods: A detailed literature search was undertaken using PubMed and Google scholar from January 1966 to October 2015 using a range of search terms. Of 921 publications, 373 papers were shortlisted and 31 articles on existing stroke-services were included. Results: We identified efficient models of ambulance transport and pre-notification. Stroke Units (SU) are available in some countries, but are relatively sparse and mostly provided by the private sector. Very few patients were thrombolysed; this could be increased with telemedicine and governmental subsidies. Adherence to secondary preventive drugs is affected by limited availability and affordability, emphasizing the importance of primary prevention. Training of paramedics, care-givers and nurses in post-stroke care is feasible. Conclusion: In this systematic review, we found several reports on evidence-based implementable stroke services in LMICs. Some strategies are economic, feasible and reproducible but remain untested. Data on their outcomes and sustainability is limited. Further research on implementation of locally and regionally adapted stroke-services and cost-effective secondary prevention programs should be a priority.

Child and Adolescent Health From 1990 to 2015: Findings From the Global Burden of Diseases, Injuries, and Risk Factors 2015 Study

Importance

Comprehensive and timely monitoring of disease burden in all age groups, including children and adolescents, is essential for improving population health.

Objective

To quantify and describe levels and trends of mortality and nonfatal health outcomes among children and adolescents from 1990 to 2015 to provide a framework for policy discussion.

Evidence Review

Cause-specific mortality and nonfatal health outcomes were analyzed for 195 countries and territories by age group, sex, and year from 1990 to 2015 using standardized approaches for data processing and statistical modeling, with subsequent analysis of the findings to describe levels and trends across geography and time among children and adolescents 19 years or younger. A composite indicator of income, education, and fertility was developed (Socio-demographic Index [SDI]) for each geographic unit and year, which evaluates the historical association between SDI and health loss.

Findings

Global child and adolescent mortality decreased from 14.18 million (95% uncertainty interval [UI], 14.09 million to 14.28 million) deaths in 1990 to 7.26 million (95% UI, 7.14 million to 7.39 million) deaths in 2015, but progress has been unevenly distributed. Countries with a lower SDI had a larger proportion of mortality burden (75%) in 2015 than was the case in 1990 (61%). Most deaths in 2015 occurred in South Asia and sub-Saharan Africa. Global trends were driven by reductions in mortality owing to infectious, nutritional, and neonatal disorders, which in the aggregate led to a relative increase in the importance of noncommunicable diseases and injuries in explaining global disease burden. The absolute burden of disability in children and adolescents increased 4.3% (95% UI, 3.1%-5.6%) from 1990 to 2015, with much of the increase owing to population growth and improved survival for children and adolescents to older ages. Other than infectious conditions, many top causes of disability are associated with long-term sequelae of conditions present at birth (eg, neonatal disorders, congenital birth defects, and hemoglobinopathies) and complications of a variety of infections and nutritional deficiencies. Anemia, developmental intellectual disability, hearing loss, epilepsy, and vision loss are important contributors to childhood disability that can arise from multiple causes. Maternal and reproductive health remains a key cause of disease burden in adolescent females, especially in lower-SDI countries. In low-SDI countries, mortality is the primary driver of health loss for children and adolescents, whereas disability predominates in higher-SDI locations; the specific pattern of epidemiological transition varies across diseases and injuries.

Conclusions and Relevance

Consistent international attention and investment have led to sustained improvements in causes of health loss among children and adolescents in many countries, although progress has been uneven. The persistence of infectious diseases in some countries, coupled with ongoing epidemiologic transition to injuries and noncommunicable diseases, require all countries to carefully evaluate and implement appropriate strategies to maximize the health of their children and adolescents and for the international community to carefully consider which elements of child and adolescent health should be monitored.

Harnessing Neuroimaging Capability in Pediatric Stroke: Proceedings of the Stroke Imaging Laboratory for Children Workshop

On June 5, 2015 the International Pediatric Stroke Study and the Stroke Imaging Laboratory for Children cohosted a unique workshop focused on developing neuroimaging research in pediatric stroke. Pediatric neurologists, neuroradiologists, interventional neuroradiologists, physicists, nurse practitioners, neuropsychologists, and imaging research scientists from around the world attended this one-day meeting. Our objectives were to (1) establish a group of experts to collaborate in advancing pediatric neuroimaging for stroke, (2) develop consensus clinical and research magnetic resonance imaging protocols for pediatric stroke patients, and (3) develop imaging-based research strategies in pediatric ischemic stroke. This article provides a summary of the meeting proceedings focusing on identified challenges and solutions and outcomes from the meeting. Further details on the workshop contents and outcomes are provided in three additional articles in the current issue of Pediatric Neurology.

Cerebrovascular Reactivity and Intellectual Outcome in Childhood Stroke With Transient Cerebral Arteriopathy

BACKGROUND

Hypercapnic-challenge blood oxygen level-dependent magnetic resonance imaging cerebrovascular reactivity (CVR), measures the regional perfusion response to altered carbon dioxide. CVR correlates with the tissue-level microvascular dysfunction and ischemic risk. Among children with arterial ischemic stroke, transient cerebral arteriopathy (TCA) is a frequent, nonprogressive unilateral intracranial arteriopathy, which typically results in basal ganglia infarction and chronic cerebral artery stenosis. Therefore TCA provides a model for studying the consequences of chronic nonprogressive stenosis using CVR and intellectual outcome. We hypothesized that children with TCA and chronic nonprogressive intracranial artery stenosis have impaired CVR distal to the stenosis and associated cognitive impairment.

METHODS

We studied children with a prior diagnosis of TCA as defined by infarction limited to the basal ganglia, internal capsule, or both; and significant (greater than 50% diameter) residual stenosis of the supraclinoid internal carotid artery, its proximal branches or both. All children had CVR, intellectual function, and infarct volumes quantified.

RESULTS

We performed CVR studies in five children at mean 8.96 years (3.33 to 14.58 years) poststroke. Impaired CVR was limited to the infarct zone and adjacent white matter in most children. Intellectual function was broadly average in all but one subject.

CONCLUSIONS

In children with typical TCA, ipsilateral cortical CVR and intellectual function seem to be preserved despite persistent arterial stenosis in the majority. These findings suggest that chronic revascularization strategies in these children may not be indicated and require further exploration in a larger cohort of children.

Abstract WMP113: Headache At Stroke Onset Is Present In Half Of All Older Children With Arterial Ischemic Stroke

Introduction: Headache at stroke onset occurs in up to a quarter of adults and is associated with younger age, female gender, right hemisphere and cerebellar infarcts. Little is known about headache at stroke onset in children.

Methods: Children (29 days-18 years) with clinical and radiographic confirmation of arterial ischemic stroke were prospectively enrolled in the International Pediatric Stroke Study from 2003-2014. Details regarding demographics, stroke presentation and infarct location were obtained from the multi-center, pediatric stroke registry. Headache at stroke presentation was classified and annotated in the registry by the individual site investigators as present, absent or unclear.

Results: We analyzed 2103 children. Half of all subjects ≥ 6 yo reported headache at stroke onset (N=509/1047, 49%; Figure). Headache was less prevalent in children < 6 yo (N=112/1056, 11%; p<0.001), though headache presentation was more commonly classified as unclear (10% vs 32%; p<0.001). In children ≥ 6 yo, headache was significantly associated with papilledema (p = 0.03) and vertigo (p = 0.01), but not with hemiparesis (p = 0.11), visual field deficit (p = 0.90), aphasia (p = 0.35), dysarthria (p = 0.44), or ataxia (p = 0.50). Headache was more common in posterior than anterior circulation infarcts (p<0.001). There was a significant association between headache and right or bilateral hemisphere infarcts (p = 0.04) but not with gender (p = 0.76).

Conclusion: Headache is more prevalent in children than adults at stroke ictus and shares similar associations, including infarcts involving the posterior circulation and right hemisphere. Headache may be under-reported in young infants and children due to pre-verbal stages of development. These findings have implications for early identification and treatment of pediatric stroke and warrant further investigation in prospective studies to distinguish stroke from more common benign mimics, including migraine.