Assessment of MR blood-oxygen-level-dependent (BOLD) cerebrovascular reactivity under general anesthesia in children with moyamoya

BACKGROUND

Moyamoya is a progressive, non-atherosclerotic cerebral arteriopathy that may present in childhood and currently has no cure. Early diagnosis is critical to prevent a lifelong risk of neurological morbidity. Blood-oxygen-level-dependent (BOLD) MRI cerebrovascular reactivity (CVR) imaging provides a non-invasive, in vivo measure of autoregulatory capacity and cerebrovascular reserve. However, non-compliant or younger children require general anesthesia to achieve BOLD-CVR imaging.

OBJECTIVE

To determine the same-day repeatability of BOLD-CVR imaging under general anesthesia in children with moyamoya.

MATERIALS AND METHODS

Twenty-eight examination pairs were included (mean patient age = 7.3 ± 4.0 years). Positive and negatively reacting voxels were averaged over signals and counted over brain tissue and vascular territory. The intraclass correlation coefficient (ICC), Wilcoxon signed-rank test, and Bland-Altman plots were used to assess the variability between the scans.

RESULTS

There was excellent-to-good (≥ 0.59) within-day repeatability in 18 out of 28 paired studies (64.3%). Wilcoxon signed-rank tests demonstrated no significant difference in the grey and white matter CVR estimates, between repeat scans (all p-values > 0.05). Bland-Altman plots of differences in mean magnitude of positive and negative and fractional positive and negative CVR estimates illustrated a reasonable degree of agreement between repeat scans and no systematic bias.

CONCLUSION

BOLD-CVR imaging provides repeatable assessment of cerebrovascular reserve in children with moyamoya imaged under general anesthesia.

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.

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.

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.

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.