Cerebrovascular Collateral Integrity in Pediatric Large Vessel Occlusion: Analysis of the Save ChildS Study

Background and Objectives:Robust cerebrovascular collaterals in adult stroke patients have been associated with longer treatment windows, better recanalization rates, and improved outcomes. No studies have investigated the role of collaterals in pediatric stroke. The primary aim was to determine whether favorable collaterals correlated with better radiographic and clinical outcomes in children with ischemic stroke who underwent thrombectomy.Methods:This study analyzed a subset of children enrolled in SaveChildS, a retrospective, multi-center, observational cohort study of 73 pediatric stroke patients who underwent thrombectomy between 2000-2018 at 27 US and European centers. Included patients had baseline angiographic imaging and follow-up modified Rankin Scale scores available for review. Posterior circulation occlusions were excluded. Cerebrovascular collaterals were graded on acute neuroimaging by 2 blinded neuroradiologists according to the Tan collateral score, where favorable collaterals are defined as >50% filling and unfavorable collaterals as <50% filling distal to the occluded vessel. Collateral status was correlated with clinical and neuroimaging characteristics and outcomes. Between-group comparisons were performed using the Wilcoxon rank-sum test for continuous variables or Fisher’s exact test for binary variables.Results:Thirty-three children (mean age 10.9 [SD±4.9]) years were included; 14 (42.4%) had favorable collaterals. Median final stroke volume as a percent of total brain volume (TBV) was significantly lower in patients with favorable collaterals (1.35% [IQR 1.14-3.76] versus 7.86% [1.54-11.07], p=0.049). Collateral status did not correlate with clinical outcome, infarct growth or final ASPECTS in our cohort. Patients with favorable collaterals had higher baseline ASPECTS (7 [IQR 6-8] versus 5.5 [4-6], p=0.006), smaller baseline ischemic volume (1.57% TBV [IQR 1.09-2.29] versus 3.42% TBV [IQR 1.26-5.33], p=0.035) and slower early infarct growth rate (2.4 mL/hr [IQR 1.5-5.1] versus 10.4 mL/hr [IQR 3.0-30.7], p=0.028).Discussion:Favorable collaterals were associated with smaller final stroke burden and slower early infarct growth rate, but not with better clinical outcome in our study. Prospective studies are needed to determine the impact of collaterals in childhood stroke.Classification of Evidence:This study provides Class II evidence that in children with ischemic stroke undergoing thrombectomy, favorable collaterals were associated with improved radiographic outcomes but not with better clinical outcomes.

P.117 Pediatric acute ischemic stroke protocols

Background: Approximately 1,000 children present with AIS annually in North America. Most suffer from long-term disability. Childhood AIS is diagnosed after a median of 23 hours post-symptom onset, limiting thrombolytic treatment options that may improve outcomes. Pediatric stroke protocols decrease time to diagnosis. AIS treatment is not uniform across Canada, nor are pediatric stroke protocols standardized. Methods: We contacted neurologists at all 16 Canadian pediatric hospitals regarding their AIS management. Results: Response rate was 100%. Seven centers have an AIS protocol and two have a protocol under development. Seven centers do not have a protocol – two redirect patients to adult neurology, and five use a case-by-case approach for management. Analysis of the seven AIS protocols reveals differences: 1) IV-tPA dosage: age-dependent 0.75-0.9 mg/kg (n=1) versus age-independent 0.9 mg/kg (n=6), with maximum doses 75 mg (n=1) or 90 mg (n=6); 2) IV-tPA lower age cut-off: 2 years (n=4) versus 3, 4 or 10 years (n=1); 3) IV-tPA exclusion criteria: PedNIHSS score <4 (n=3), <5 (n=1), or <6 (n=3); 4) Pre-treatment neuroimaging: CT (n=3) versus MRI (n=4); 5) Intra-arterial tPA use (n=3). Conclusions: The seven Canadian pediatric AIS protocols show prominent differences. We plan a teleconference discussing a Canadian pediatric AIS consensus approach.

Cerebral blood flow and cognitive outcome after pediatric stroke in the middle cerebral artery

Adaptive recovery of cerebral perfusion after pediatric arterial ischemic stroke (AIS) is sought to be crucial for sustainable rehabilitation of cognitive functions. We therefore examined cerebral blood flow (CBF) in the chronic stage after stroke and its association with cognitive outcome in patients after pediatric AIS. This cross-sectional study investigated CBF and cognitive functions in 14 patients (age 13.5 ± 4.4 years) after pediatric AIS in the middle cerebral artery (time since AIS was at least 2 years prior to assessment) when compared with 36 healthy controls (aged 13.8 ± 4.3 years). Cognitive functions were assessed with neuropsychological tests, CBF was measured with arterial spin labeled imaging in the anterior, middle, and posterior cerebral artery (ACA, MCA, PCA). Patients had significantly lower IQ scores and poorer cognitive functions compared to healthy controls (p < 0.026) but mean performance was within the normal range in all cognitive domains. Arterial spin labeled imaging revealed significantly lower CBF in the ipsilesional MCA and PCA in patients compared to healthy controls. Further, we found significantly higher interhemispheric perfusion imbalance in the MCA in patients compared to controls. Higher interhemispheric perfusion imbalance in the MCA was significantly associated with lower working memory performance. Our findings revealed that even years after a pediatric stroke in the MCA, reduced ipsilesional cerebral blood flow occurs in the MCA and PCA and that interhemispheric imbalance is associated with cognitive performance. Thus, our data suggest that cerebral hypoperfusion might underlie some of the variability observed in long-term outcome after pediatric stroke.

Pediatric unilateral spatial neglect: A systematic review

PURPOSE: Unilateral spatial neglect (USN), an inability to attend to one side of space or one’s body, is commonly reported in adult stroke survivors and is associated with poor outcomes. USN has been reported in pediatric survivors of stroke, but its impact is unclear. The purpose of this systematic review was to summarize and evaluate the literature regarding USN in pediatric stroke survivors. METHODS: PRISMA guidelines, Scopus, CINAHL, PubMed, and other relevant databases were searched with terms including “children”, “stroke”, and “unilateral neglect”, with the ages of participants limited from to birth to 18 years. Data were extracted from studies on the clinical presentation of pediatric USN, the assessment of this condition, treatment options, or USN recovery. RESULTS: A total of 18 articles met inclusion criteria. There were no current prevalence data available. USN presents similarly in children compared to adults. Several different USN assessments were used, however, there were little data regarding treatment options. Furthermore, the data suggest that not all children fully recover. CONCLUSION: This systematic review reveals a lack of quality research to inform the assessment and treatment of children with USN. Although the literature spans decades, there remain no guidelines for standardized assessment or treatment. Similar to adults, paper-and-pencil testing may be less able to identify USN than functional assessments. It is likely that there are children who struggle with undetected USN-related deficits years after their injuries. With a rise of pediatric stroke survivors, there is a pressing need for clinicians to be educated about USN in children, clinical presentations, assessments, and treatments.