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

Lateralized Rhythmic Delta Activity and Lateralized Periodic Discharges in Critically Ill Pediatric Patients

PURPOSE

To evaluate the clinical and electrographic characteristics of critically ill pediatric patients with lateralized rhythmic delta activity (LRDA) and compare them with patients with lateralized periodic discharges (LPDs).

METHODS

This was a retrospective study examining consecutive critically ill pediatric patients (1 month-18 years) with LRDA or LPDs monitored on continuous electroencephalography. Clinical, radiologic, and electrographic characteristics; disease severity; and acute sequelae were compared between the two groups.

RESULTS

Of 668 pediatric patients monitored on continuous electroencephalography during the study period, 12 (1.79%) patients had LRDA and 15 (2.24%) had LPDs. The underlying etiologies were heterogeneous with no difference in the acuity of brain MRI changes between both groups. Lateralized rhythmic delta activity and LPDs were concordant with the side of MRI abnormality in most patients [85.7% (LRDA) and 83.3% (LPD)]. There was no difference in the measures of disease severity between both groups. Seizures were frequent in both groups (42% in the LRDA group and 73% in the LPD group). Patients in the LPD group had a trend toward requiring a greater number of antiseizure medications for seizure control (median of 4 vs. 2 in the LRDA group, p = 0.09), particularly those patients with LPDs qualifying as ictal-interictal continuum compared with those without ictal-interictal continuum ( p = 0.02).

CONCLUSIONS

Lateralized rhythmic delta activity and LPDs are uncommon EEG findings in the pediatric population. Seizures occur commonly in patients with these patterns. Seizures in patients with LPDs, especially those qualifying as ictal-interictal continuum, showed a trend toward being more refractory. Larger studies are needed in the future to further evaluate these findings.

Endovascular thrombectomy for childhood stroke (Save ChildS Pro): an international, multicentre, prospective registry study

BACKGROUND

Emerging evidence suggests that endovascular thrombectomy is beneficial for treatment of childhood stroke, but the safety and effectiveness of endovascular thrombectomy has not been compared with best medical treatment. We aimed to prospectively analyse functional outcomes of endovascular thrombectomy versus best medical treatment in children with intracranial arterial occlusion stroke.

METHODS

In this prospective registry study, 45 centres in 12 countries across Asia and Australia, Europe, North America, and South America reported functional outcomes for children aged between 28 days and 18 years presenting with arterial ischaemic stroke caused by a large-vessel or medium-vessel occlusion who received either endovascular thrombectomy plus best medical practice or best medical treatment alone. Intravenous thrombolysis was considered part of best medical treatment and therefore permitted in both groups. The primary outcome was the difference in median modified Rankin Scale (mRS) score between baseline (pre-stroke) and 90 days (±10 days) post-stroke, assessed by the Wilcoxon rank test (α=0·05). Efficacy outcomes in the endovascular thrombectomy and best medical treatment groups were compared in sensitivity analyses using propensity score matching. The Save ChildS Pro study is registered at the German Clinical Trials Registry, DRKS00018960.

FINDINGS

Between Jan 1, 2020, and Aug 31, 2023, of the 241 patients in the Save ChildS Pro registry, 208 were included in the analysis (115 [55%] boys and 93 [45%] girls). 117 patients underwent endovascular thrombectomy (median age 11 years [IQR 6-14]), and 91 patients received best medical treatment (6 years [3-12]; p<0·0001). The median Pediatric National Institutes of Health Stroke Scale (PedNIHSS) score on admission was 14 (IQR 10-19) in the endovascular thrombectomy group and 9 (5-13) in the best medical treatment group (p<0·0001). Both treatment groups had a median pre-stroke mRS score of 0 (IQR 0-0) at baseline. The change in median mRS score between baseline and 90 days was 1 (IQR 0-2) in the endovascular thrombectomy group and 2 (1-3) in the best medical treatment group (p=0·020). One (1%) patient developed a symptomatic intracranial haemorrhage (this patient was in the endovascular thrombectomy group). Six (5%) patients in the endovascular thrombectomy group and four (5%) patients in the best medical treatment group had died by day 90 (p=0·89). After propensity score matching for age, sex, and PedNIHSS score at hospital admission (n=79 from each group), the change in median mRS score between baseline and 90 days was 1 (IQR 0-2) in the endovascular thrombectomy group and 2 (1-3) in the best medical treatment group (p=0·029). Regarding the primary outcome for patients with suspected focal cerebral arteriopathy, endovascular thrombectomy (n=18) and best medical treatment (n=33) showed no difference in 90-day median mRS scores (2 [IQR 1-3] vs 2 [1-4]; p=0·074).

INTERPRETATION

Clinical centres tended to select children with more severe strokes (higher PedNIHSS score) for endovascular thrombectomy. Nevertheless, endovascular thrombectomy was associated with improved functional outcomes in paediatric patients with large-vessel or medium-vessel occlusions compared with best medical treatment. Future studies need to investigate whether the positive effect of endovascular thrombectomy is confined to older and more severely affected children.

FUNDING

None.

Mechanical Thrombectomy for Pediatric Stroke: Focal Cerebral Arteriopathy Versus Cardioembolic Etiologies-Pooled Analysis of the Save ChildS and KidClot Cohort

BACKGROUND

The study aimed to compare outcomes of mechanical thrombectomy (MT) in pediatric patients with acute ischemic stroke (AIS) caused by focal cerebral arteriopathy (FCA) versus cardioembolism (CE).

METHODS

Data from the Save ChildS and KidClot cohorts were merged. Children with AIS because of FCA or CE that underwent MT were included. The study used the Childhood Arterial Ischemic Stroke Standardized Classification and Diagnostic Evaluation (CASCADE) for stroke cause assessment. Descriptive statistics and multivariable regression models were used to analyze final modified thrombolysis in cerebral infarction (mTICI) scores, periprocedural complications, and functional outcomes assessed by the modified Rankin scale (mRS) at 6 to 12 months.

RESULTS

The analysis included 60 children with 14 FCA and 46 CE cases. CE etiology was associated with better revascularization (good to excellent thrombolysis in cerebral infarction scores) and shift toward better outcomes (common adjusted odds ratio of mRs for CE vs FCA: 0.27, 95% CI: [0.06-0.97], p = 0.039), with no difference in favorable outcome rates. FCA was associated with significantly lower rates of excellent revascularization (21% vs 65%, p < 0.001). No difference in complications' rates was observed between the groups (7.2% in FCA vs 5.5%, p = 0.69).

INTERPRETATION

We found that pediatric AIS because of CE etiology has more favorable procedural outcomes compared to FCA following MT. This translated to mixed functional outcomes that may be more favorable in the CE group. These findings highlight the need for further research to refine treatment protocols for pediatric stroke, particularly in understanding and managing FCA in children. ANN NEUROL 2024.

Under (back) pressure: Better collateral flow may facilitate clot removal in ischemic stroke: A systematic review and meta-analysis

BACKGROUND

Collateral status may facilitate clot removal and affect rates of successful reperfusion following endovascular therapy (EVT) for acute ischemic stroke (AIS).

METHODS

Following the PRISMA guidelines, a systematic literature review of the English language literature was conducted using PubMed, Scopus, Web of Science, and Embase. Papers which focused on collateral status and patients treated with EVT for AIS were included in our analysis. Outcomes of interest included collateral score grading, rates of successful reperfusion defined as thrombolysis in cerebral infarction (TICI) score 2b-3 and onset to revascularization time. We calculated pooled odds ratio (OR) or mean difference (MD) and their corresponding 95% confidence intervals (CI) based on collateral status.

RESULTS

16 studies, with 6073 patients, were included in our analysis. Among the included studies, there were six different collateral grading scales, which were dichotomized into "good to moderate" and "poor" collaterals. Odds of successful reperfusion were significantly higher among patients with good to moderate collateral circulation compared to those with poor collaterals (OR =  1.61; 95% CI = 1.24 to 2.09; P-value < 0.001); however, there was heterogeneity among included studies (I2= 5 4%; P-value = 0.008). Onset to revascularization time was comparable between patients with good to moderate collateral circulation compared to those with poor collaterals (MD = 3.91 min; 95% CI = -8.71 to 16.53; P-value = 0.544); however, there was heterogeneity among included studies (I2= 60%; P-value = 0.014).

CONCLUSIONS

The presence of good collaterals may increase the odds of achieving successful reperfusion following EVT for AIS. Improved collateral flow was associated with improved angiographic outcomes, although future work is needed to determine if a causal relationship exists.

Hyperacute Perfusion Imaging Before Pediatric Thrombectomy: Analysis of the Save ChildS Study

BACKGROUND AND OBJECTIVES

Perfusion imaging can identify adult patients with salvageable brain tissue who would benefit from thrombectomy in later time windows. The feasibility of obtaining hyperacute perfusion sequences in pediatric stroke is unknown. The aim of this study was to determine whether contrast perfusion imaging delayed time to treatment and to assess perfusion profiles in children with large vessel occlusion stroke.

METHODS

The Save ChildS retrospective cohort study (January 2000-December 2018) enrolled children (1 month-18 years) with stroke who underwent thrombectomy from 27 European and U.S. stroke centers. This secondary analysis included patients with anterior circulation occlusion and available imaging for direct review by the neuroimaging core laboratory. Between-group comparisons were performed using the Wilcoxon rank-sum exact test for continuous variables or Fisher exact test for binary variables. Given the small number of patients, evaluation of perfusion imaging parameters was performed descriptively only.

RESULTS

Of 33 patients with available neuroimaging, 15 (45.4%) underwent perfusion (CT perfusion n = 6; MR perfusion n = 9); all were technically adequate. The median time from onset to recanalization did not differ between groups {4 hours (interquartile range [IQR] 4-7.5) perfusion+; 3.4 hours (IQR 2.5-6.5) perfusion-, p = 0.158}. Target mismatch criteria were met by 10/15 (66.7%) patients and did not correlate with reperfusion status or functional outcome. The hypoperfusion intensity ratio (HIR) was favorable in 11/15 patients and correlated with older age but not NIHSS, time to recanalization, or stroke etiology. Favorable HIR was associated with better functional outcome at 6 months (Pediatric Stroke Outcome Measure 1.0 [IQR 0.5-2.0] vs 2.0 [1.5-3.0], p = 0.026) and modified Rankin Scale 1.0 [0-1] vs 2.0 [1.5-3.5], p = 0.048) in this small sample.

DISCUSSION

Automated perfusion imaging is feasible to obtain acutely in children and does not delay time to recanalization. Larger prospective studies are needed to determine biomarkers of favorable outcome in pediatric ischemic stroke and to establish core and penumbral thresholds in children.

Case Report: Successful Anterior Circulation Thrombectomy After 24 Hours in An Adolescent

BACKGROUND

Arterial ischemic stroke in children comes with the potential for morbidity and mortality and can result in high cost of care and decreased quality of life among survivors. Children with arterial ischemic stroke are increasingly being treated with mechanical thrombectomy, but little is known about the risks and benefits 24 hours after a patient's last known well (LKW) time.

METHODS

A 16-year-old female presented with acute onset of dysarthria and right hemiparesis with LKW time 22 hours prior. Pediatric National Institutes of Health Stroke Scale score was 12. Magnetic resonance imaging showed diffusion restriction and T2 hyperintensity primarily in the left basal ganglia. Magnetic resonance angiography revealed left M1 occlusion. Arterial spin labeling showed a large apparent perfusion deficit. She underwent thrombectomy with TICI3 recanalization 29.5 hours after LKW time.

RESULTS

At 2-month follow-up, her examination showed moderate right-hand weakness and mild diminished sensation of the right arm.

CONCLUSIONS

Adult thrombectomy trials include patients up to 24 hours from their LKW time and suggest that some patients maintain a favorable perfusion profile for over 24 hours. Without intervention many go on to experience infarct expansion. The persistence of a favorable perfusion profile likely reflects robust collateral circulation. We hypothesized our patient was relying on collateral circulation to maintain the noninfarcted areas of her left middle cerebral artery territory. Owing to concern for eventual collateral failure, thrombectomy outside of the 24-hour window was performed. This case serves as a call to action to better understand the impact of collateral circulation on cerebral perfusion in children with large vessel occlusions and delineate which children may benefit from thrombectomy in a delayed time window.

Impact of edema formation on functional outcome in pediatric stroke patients

BACKGROUND

Quantitative lesion net water uptake (NWU) has been described as an imaging biomarker reflecting vasogenic edema as an early indicator of infarct progression. We hypothesized that edema formation measured by NWU is higher in children compared to adults but despite this functional outcome may be better in children.

METHODS

This study analyzed children enrolled in the Save ChildS Study who had baseline and follow-up computed tomography available and the data were compared to adult patients.

RESULTS

Some 207 patients, of whom 13 were children and 194 were adults, were analyzed. Median NWU at baseline was 7.8% (IQR: 4.3-11.3), and there were no significant differences between children and adults (7.5% vs. 7.8%; p = 0.87). The early edema progression rate was 3.0%/h in children and 2.3%/h in adults. Median ΔNWU was 15.1% in children and 10.5% in adults. Children had significantly more often excellent (mRS 0-1; children 10/13 = 77% vs. adults 28/196 = 14%; p < 0.0001) and favorable clinical outcomes (mRS 0-2, 12/13 = 92% vs. 39/196 = 20%; p < 0.0001).

CONCLUSIONS

In this study, clinical outcomes in children with large vessel occlusion strokes were better than in adults despite similar clinical and imaging characteristics and similar edema formation. This may be impacted by the generally better outcomes of children after strokes but may demonstrate that the degree of early ischemic changes using Alberta Stroke Program Early Computed Tomography Score (ASPECTS) and edema progression rate may not be a reason for exclusion from endovascular thrombectomy.

Neuroimaging in Pediatric Stroke

Pediatric stroke is unfortunately not a rare condition. It is associated with severe disability and mortality because of the complexity of potential clinical manifestations, and the resulting delay in seeking care and in diagnosis. Neuroimaging plays an important role in the multidisciplinary response for pediatric stroke patients. The rapid development of adult endovascular thrombectomy has created a new momentum in health professionals caring for pediatric stroke patients. Neuroimaging is critical to make decisions of identifying appropriate candidates for thrombectomy. This review article will review current neuroimaging techniques, imaging work-up strategies and special considerations in pediatric stroke. For resources limited areas, recommendation of substitute imaging approaches will be provided. Finally, promising new techniques and hypothesis-driven research protocols will be discussed.

Acute Hospital Management of Pediatric Stroke

The field of pediatric stroke has historically been hampered by limited evidence and small patient cohorts. However the landscape of childhood stroke is rapidly changing due in part to increasing awareness of the importance of pediatric stroke and the emergence of dedicated pediatric stroke centers, care pathways, and alert systems. Acute pediatric stroke management hinges on timely diagnosis confirmed by neuroimaging, appropriate consideration of recanalization therapies, implementation of neuroprotective measures, and attention to secondary prevention. Because pediatric stroke is highly heterogenous in etiology, management strategies must be individualized. Determining a child's underlying stroke etiology is essential to appropriately tailoring hyperacute stroke management and determining best approach to secondary prevention. Herein, we review the methods of recognition, diagnosis, management, current knowledge gaps and promising research for pediatric stroke.