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.

Recommendations for the Management of Initial and Refractory Pediatric Status Dystonicus

Status dystonicus is the most severe form of dystonia with life-threatening complications if not treated promptly. We present consensus recommendations for the initial management of acutely worsening dystonia (including pre-status dystonicus and status dystonicus), as well as refractory status dystonicus in children. This guideline provides a stepwise approach to assessment, triage, interdisciplinary treatment, and monitoring of status dystonicus. The clinical pathways aim to: (1) facilitate timely recognition/triage of worsening dystonia, (2) standardize supportive and dystonia-directed therapies, (3) provide structure for interdisciplinary cooperation, (4) integrate advances in genomics and neuromodulation, (5) enable multicenter quality improvement and research, and (6) improve outcomes. © 2024 International Parkinson and Movement Disorder Society.

Long-term clinical and radiological trajectories of craniocervical vasculopathy in children with PHACE syndrome

AIM

To describe the rates of stroke and craniocervical vasculopathy progression in children with posterior fossa malformations, hemangioma, arterial anomalies, coarctation of the aorta/cardiac defects, and eye abnormalities (PHACE) syndrome.

METHOD

A single-center, retrospective natural history study of children with PHACE syndrome. Clinical and sequential neuroimaging data were reviewed to study the characteristics and progression of vasculopathy and calculate the rates of arterial ischemic stroke (AIS) and transient ischemic stroke (TIA). Vasculopathy progression was defined as worsening or new vascular findings on follow-up magnetic resonance angiography.

RESULTS

Thirty-four children with cerebrovascular abnormalities at the PHACE syndrome diagnosis were studied (age range = 2 to 18 years, 85% females). Median age at the initial diagnosis was 5.5 months (interquartile range = 1-52 months); median age at the last follow-up was 8 years 6 months (range = 2-18 years). Overall, 10 (29%) patients had radiological progression of their vasculopathy, with a cumulative progression-free rate of 73% (95% confidence interval [CI] = 0.57-0.89), and a cumulative TIA-free and AIS-free rate of 87% (95% CI = 0.745-0.99). Vasculopathy was continuously progressive in six patients (18%) at the last follow-up. Three patients (9%) had TIA and all had progressive vasculopathy. One patient had presumed perinatal AIS at the initial PHACE diagnosis, while no other patient experienced an AIS during the follow-up.

INTERPRETATION

In children with PHACE syndrome, craniocervical vasculopathy is non-progressive and asymptomatic in the majority of cases. The risk of ischemic stroke in these children is very low. Larger and prospective studies are necessary to confirm these findings.

A Video is Worth a Thousand Words: The Use of Home Videos in Pediatric Neurology

The use of home video recordings (HVRs) may aid in the diagnosis of neurological disorders. However, this practice remains underutilized. Through an anonymous survey, we sought to understand the perspectives of healthcare providers regarding the sharing of HVRs alongside referrals for responsive and economical pediatric neurology care. This was timely given COVID-19 has worsened wait times for diagnosis and consequently treatment. Most providers agree that sharing of HVRs improves patient care (93.1%: 67/73) and prevents both additional investigations (67%: 49/73) and hospital admissions (68.5%: 50/73). However, a minority of providers (21.9 %: 16/73) currently share HVRs alongside their referrals.

Building the Bridge From Pediatric to Adult Neurological Care

In this brief communication, we discuss the current landscape and unmet needs of pediatric to adult transition care in neurology. Optimizing transition care is a priority for patients, families, and providers with growing discussion in neurology. We also introduce the activities of the University of Toronto Pediatric-Adult Transition Working Group - a collaborative interdivisional and inter-subspeciality group of faculty, advanced-practice providers, trainees, and patient-family advisors pursuing collaboration with patients, families, and universities from across Canada. We envision that these efforts will result in a national neurology transition strategy that will inform designation of health authority attention and funding.

Generating Items for a Novel Bedside Dysphagia Screening Tool Post Acute Pediatric Stroke

Bedside dysphagia assessment protocols are not well developed in acute pediatric stroke unlike adults. The objective of this study was to identify items deemed relevant and feasible by expert consensus to inform the development of a bedside dysphagia screening tool for acute pediatric stroke. A two-phase study was conducted: (1) literature review and expert consultation generated a comprehensive list of dysphagia assessment items; (2) items were formatted in an online survey asking respondents opinion of relevance to acute pediatric stroke and feasibility for bedside administration by a trained health professional. The Dillman Tailored Design approach optimized response rate. Respondents were identified using the snowball method. Speech-language pathologists with > 2 years in pediatric dysphagia were invited to complete the survey. Demographic and practice variables were compared using univariate statistics. Item relevance and feasibility were made using binary or ordinal responses, combined to derive item-content validity indices (I-CVI) to guide item reduction. Items with I-CVI > 0.78 (excellent content validity) were moved forward to tool development. Of the 71 invited respondents, 57(80.3%) responded, of which 34(59.6%) were from North America. Sixty-one items were generated of which 4(6.6%) items were rated 'to keep'. These were face symmetry (I-CVI:0.89), salivary control (I-CVI:0.95), alertness (I-CVI:0.89) and choking (I-CVI:0.84). Of all respondents, 31(54.4%) endorsed swallowing trials, of which 25(80.6%) endorsed thin liquid by teaspoon (n = 17, 68%) or open cup (n = 20, 80%). We identified candidate items for bedside dysphagia screening with excellent content validity for acute pediatric stroke patients. Next steps include assessment of the psychometric value of each item in identifying dysphagia in children in the acute stage of recovery from stroke.

The State of Inpatient Child Neurology: A Survey of North American Academic Programs

BACKGROUND AND OBJECTIVES

Inpatient child neurology programs provide essential services for children. We sought to understand the current structure and challenges of inpatient pediatric neurologic care delivery in academic programs in North America.

METHODS

We identified a single child neurologist from 39 of the first 40 programs on the 2019-2020 US News and World Report ranking and 3 large Canadian programs to be invited to participate in an inpatient focused survey. In October 2020, these 42 child neurologists were invited to complete an anonymous on-line survey including 37 questions about the structure, workload, and challenges of their inpatient program. Data were analyzed descriptively.

RESULTS

We received responses from 30/42 (71%) invited child neurologists from unique programs. Most (22/30, 73%) were Child Neurology Program Directors, Inpatient Directors, and/or Division Chiefs. Two-thirds (20/30, 67%) reported a total of 2-4 inpatient services. Two-thirds (20/30, 67%) reported a primary neurology admitting service. Nearly two-thirds (19/30, 63%) reported a separate intensive care unit service, and approximately one-third (11/30, 37%) reported a separate stroke/vascular service. Half of the respondents (15/30, 50%) reported some attendings whose primary clinical effort is in the inpatient setting. Over half (17/30, 57%) reported having trainees interested in inpatient-focused careers. Approximately half (16/30, 53%) reported a full-time equivalent metric for inpatient time, and under half (13/30, 43%) reported the use of critical-care billing. Most respondents (26/30, 87%) endorsed that inpatient attendings frequently complete documentation/sign notes outside of normal daytime hours. During night call, attendings commonly spend 30 minutes-2 hours on patient care-related phone calls between 5 and 10 pm (24/30, 80%) and receive 1-3 patient care-related phone calls after 10 pm (21/30, 70%). Faculty burnout was the biggest inpatient-specific challenge before the coronavirus disease 2019 (COVID-19) pandemic (25/30, 83%), and concern about faculty well-being during the COVID-19 pandemic was reported in nearly all respondents (28/30, 93%).

DISCUSSION

Academic child neurology programs in North America implement varied models for inpatient care delivery and face common challenges. The information presented in this study serves to stimulate discussion, help optimize operations, and encourage novel approaches to accomplish work and advance careers in academic inpatient child neurology.

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.

Multicenter Study of the Impact of COVID-19 Shelter-In-Place on Tertiary Hospital-based Care for Pediatric Neurologic Disease

Objective

To describe changes in hospital-based care for children with neurologic diagnoses during the initial 6 weeks following regional Coronavirus 2019 Shelter-in-Place orders.

Methods

This retrospective cross-sectional study of 7 US and Canadian pediatric tertiary care institutions included emergency and inpatient encounters with a neurologic primary discharge diagnosis code in the initial 6 weeks of Shelter-in-Place (COVID-SiP), compared to the same period during the prior 3 years (Pre-COVID). Patient demographics, encounter length, and neuroimaging and electroencephalography use were extracted from the medical record.

Results

27,900 encounters over 4 years were included. Compared to Pre-COVID, there was a 54% reduction in encounters during Shelter-in-Place. COVID-SiP patients were younger (median 5 years vs 7 years). The incidence of encounters for migraine fell by 72%, and encounters for acute diagnoses of status epilepticus, infantile spasms, and traumatic brain injury dropped by 53%, 55%, and 56%, respectively. There was an increase in hospital length of stay, relative utilization of intensive care, and diagnostic testing (long-term electroencephalography, brain MRI, and head CT (all P<.01)).

Conclusion

During the initial 6 weeks of SiP, there was a significant decrease in neurologic hospital-based encounters. Those admitted required a high level of care. Hospital-based neurologic services are needed to care for acutely ill patients. Precise factors causing these shifts are unknown and raise concern for changes in care seeking of patients with serious neurologic conditions. Impacts of potentially delayed diagnosis or treatment require further investigation.

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.

Distinct Clinical and Radiographic Phenotypes in Pediatric Patients With Moyamoya

BACKGROUND

Given the expanding evidence of clinico-radiological differences between moyamoya disease (MMD) and moyamoya syndrome (MMS), we compared the clinical and radiographic features of childhood MMD and MMS to identify predictors of ischemic event recurrence.

METHODS

We reviewed a pediatric moyamoya cohort followed between 2003 and 2019. Clinical and radiographic characteristics at diagnosis and follow-up were abstracted. Comparisons between MMD and MMS as well as between MMD and two MMS subgroups (neurofibromatosis [MMS-NF1] and sickle cell disease [MMS-SCD]) were performed.

RESULTS

A total of 111 patients were identified. Patients with MMD presented commonly with transient ischemic attacks (TIAs) (35 % MMD versus 13% MMS-NF1 versus 9.5% MMS-SCD; P = 0.047). Symptomatic stroke presentation (MMD 37% versus MMS-NF1 4% versus 33%; P = 0.0147) and bilateral disease at diagnosis (MMD 73% versus MMS-NF1 22 % versus MMS-SCD 67%; P = 0.0002) were uncommon in MMS-NF1. TIA recurrence was common in MMD (hazard ratio 2.86; P = 0.001). The ivy sign was absent on neuroimaging in a majority of patients with MMS-SCD (MMD 67% versus MMS-NF1 52% versus MMS-SCD 9.5%; P = 0.0002). Predictors of poor motor outcome included early age at diagnosis (odds ratio [OR] 8.45; P = 0.0014), symptomatic stroke presentation (OR 6.6; P = 0.019), and advanced Suzuki stage (OR 3.59; P = 0.019).

CONCLUSIONS

Moyamoya exhibits different phenotypes based on underlying etiologies. Frequent TIAs is a common phenotype of MMD and symptomatic stroke presentation a common feature of MMD and MMS-SCD, whereas unilateral disease and low infarct burden are common in MMS-NF1. In addition, absence of ivy sign is a common phenotype in MMS-SCD.

Epileptogenic modulation index and synchronization in hypsarrhythmia of West syndrome secondary to perinatal arterial ischemic stroke

OBJECTIVE

Perinatal arterial ischemic stroke (PAIS) is associated with epileptic spasms of West syndrome (WS) and long term Focal epilepsy (FE). The mechanism of epileptogenic network generation causing hypsarrhythmia of WS is unknown. We hypothesized that Modulation index (MI) [strength of phase-amplitude coupling] and Synchronization likelihood (SL) [degree of connectivity] could interrogate the epileptogenic network in hypsarrhythmia of WS secondary to PAIS.

METHODS

We analyzed interictal scalp electroencephalography (EEG) in 10 WS and 11 FE patients with unilateral PAIS. MI between gamma (30-70 Hz) and slow waves (3-4 Hz) was calculated to measure phase-amplitude coupling. SL between electrode pairs was analyzed in 9-frequency bands (5-delta, theta, alpha, beta, gamma) to examine inter- and intra-hemispheric connectivity.

RESULTS

MI was higher in affected hemispheres in WS (p = 0.006); no differences observed in FE. Inter-hemispheric SL of 3-delta, theta, alpha, beta, gamma bands was significantly higher in WS (p < 0.001). In WS, modified Z-Score of intra-hemispheric SL values in 3-delta, theta, alpha, beta and gamma in the affected hemispheres were significantly higher than those in the unaffected hemispheres (p < 0.001) as well as 0.5-4 Hz (p = 0.004).

CONCLUSIONS

The significantly higher modulation in affected hemisphere and stronger inter- and intra-hemispheric connectivity generate hypsarrhythmia of WS secondary to PAIS.

SIGNIFICANCE

Epileptogenic cortical-subcortical transcallosal networks from affected hemisphere post-PAIS provokes infantile spasms.

Swallowing, Oral Motor, Motor Speech, and Language Impairments Following Acute Pediatric Ischemic Stroke

BACKGROUND AND PURPOSE

Following adult stroke, dysphagia, dysarthria, and aphasia are common sequelae. Little is known about these impairments in pediatric stroke. We assessed frequencies, co-occurrence and associations of dysphagia, oral motor, motor speech, language impairment, and caregiver burden in pediatric stroke.

METHODS

Consecutive acute patients from term birth-18 years, hospitalized for arterial ischemic stroke (AIS), and cerebral sinovenous thrombosis, from January 2013 to November 2018 were included. Two raters reviewed patient charts to detect documentation of in-hospital dysphagia, oral motor dysfunction, motor speech and language impairment, and caregiver burden, using a priori operational definitions for notation and assessment findings. Other variables abstracted included demographics, preexisting conditions, stroke characteristics, and discharge disposition. Impairment frequencies were obtained by univariate and bivariate analysis and associations by simple logistic regression.

RESULTS

A total of 173 patients were stratified into neonates (N=67, mean age 2.9 days, 54 AIS, 15 cerebral sinovenous thrombosis) and children (N=106, mean age 6.5 years, 73 AIS, 35 cerebral sinovenous thrombosis). Derived frequencies of impairments included dysphagia (39% neonates, 41% children); oral motor (6% neonates, 41% children); motor speech (37% children); and language (31% children). Common overlapping impairments included oral motor and motor speech (24%) and dysphagia and motor speech (23%) in children. Associations were found only in children between stroke type (AIS over cerebral sinovenous thrombosis) and AIS severity (more severe deficit at presentation) for all impairments except feeding impairment alone. Caregiver burden was present in 58% patients.

CONCLUSIONS

For the first time, we systematically report the frequencies and associations of dysphagia, oral motor, motor speech, and language impairment during acute presentation of pediatric stroke, ranging from 30% to 40% for each impairment. Further research is needed to determine long-term effects of these impairments and to design standardized age-specific assessment protocols for early recognition following stroke.

Long-term cognitive outcomes after cerebral sinovenous thrombosis in childhood

AIM

To assess long-term cognitive function in children after cerebral sinovenous thrombosis (CSVT).

METHOD

Children with CSVT, who had neuropsychological testing for intellectual ability, executive function, attention, language, or behavior, were included in a prospective observational study. Outcomes were compared with normative means using one-sample t-tests. Predictors of abnormal function were examined using logistic regression.

RESULTS

Fifty children with CSVT were included (median age at diagnosis 2y 10mo, interquartile range 7d-6y 10mo; 35 males, 15 females). The median follow-up time was 4 years 2 months (interquartile range 2y 8mo-6y 4mo). Compared with normative means, children with CSVT had lower mean (± standard deviation) full-scale IQ, working memory, and processing speed scores (93.3±16, p=0.01; 93.6±16, p=0.04; 93.7±15.3, p=0.02 respectively). They also had lower scores in executive function, attention, and language domains. Refractory seizure at presentation was associated with a trend in behavioral problems (odds ratio [OR] 6.3, 95% confidence interval [CI] 0.9-46, p=0.07). Females were less likely to experience processing speed difficulties (OR 0.22, 95% CI 0.04-1.3, p=0.09). Incomplete recanalization was associated with a greater risk of abnormal verbal comprehension (OR 5.3, 95% CI 0.93-30.5, p=0.059).

INTERPRETATION

Children with CSVT as a group performed below age expectations on standardized neuropsychological tests, although there was variability across individuals and cognitive domains. Larger studies are needed to evaluate predictors of cognitive deficits in children with CSVT.

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.

Bow hunter syndrome: A rare yet important etiology of posterior circulation stroke

A6-year-oldgirl presented with acute-onset headache andfluctuating right-sided weakness.HerPedNIHSSwas13. Brain MRI/MRA showed acute pontine arterial ischemic stroke(AIS)and remote right cerebellar and thalamic infarcts.No antecedent trauma or other stroke risk factors were identified. Clinical suspicion of bow hunter syndromewas raised. CTshowed congenital C2-C3 fusion and dynamic angiogramconfirmed the diagnosis. The management challenges of this rare condition are discussed below.

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 TP409: Cognitive Function in Cerebral Arteriopathy: An Evaluation of the Effects of Blood Pressure and Body Mass Index

Background: Cerebral arteriopathy (CA) is a major risk factor for childhood arterial ischemic stroke and is associated with significant cognitive impairments. Disease-related characteristics partially explain the variability observed in specific cognitive outcomes. Adult studies demonstrate an association between stroke risk factors such as increased body mass index (BMI) and blood pressure (BP) and cognitive function, suggesting a more diffuse mechanism of brain injury. We aimed to evaluate the association between BMI and BP with cognitive function in children with CA.

Methods: We conducted a cross-sectional study in children with CA and no stroke, aged 5-18 years. Children were evaluated using Wechsler Intelligence Scale for Children (WISC), Adaptive Behaviour Assessment System (ABAS), Beery-Buktenica Developmental Test (BEERY) and Behaviour Assessment System for Children (BASC). Children with BMI≥85 th percentile were classified as overweight and those with systolic or diastolic BP≥90 th percentile were classified as prehypertensive/hypertensive (Pre-HTN).

Results: Of 88 children with CA, 38 were included (63% female; median age:11.3 years). Pre-HTN and overweight were present in 26% and 29%, respectively. Significant negative correlations were found between BMI and working memory (R 2 =-0.5, p=0.01) and perceptual reasoning (R 2 =-0.4, p=0.04) of the WISC. Beery-perception scores correlated significantly with diastolic BP (R 2 =-0.5, p=0.02) and BMI (R 2 =-0.7, p=0.01). The social composite score of the ABAS correlated significantly with the BMI (R 2 =-0.7, p=0.04). Overweight children had significantly lower BEERY-motor scores (53.5±30.4 vs 84.8±17.8, p=0.03) and higher BASC-externalizing problems (58±11.4 vs 47.9±8.4, p=0.02) compared to children with normal weight. Hypertensive children displayed significantly lower BEERY-visual perception scores (63.5±26.2 vs 92.2±12.5, p=0.01).

Conclusion: Increased BMI and BP may contribute to cognitive impairments observed in children with CA. We suggest that a more diffuse mechanism of brain injury is responsible for the specific cognitive impairments associated with increased BMI and BP. Larger controlled studies involving structural and perfusion imaging are needed.

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 TMP114: Functional and Structural Network Reorganization in Higher-Order Language Following Neonatal Stroke

Introduction: Neonatal arterial ischemic stroke (NAIS) is a common form of pediatric stroke often affecting classical language areas in the brain’s left hemisphere. While children with NAIS can acquire basic language skills, adolescence typically reveals the emergence of deficits in higher-order language, such as syntactic language. The reorganization of functional and structural brain networks may provide insight into later-emerging language outcomes and serve as a biomarker in prognostication.

Methods: A cross-sectional study of eight children with unilateral NAIS (5F; 12.3±3.3 years) and seven neurotypical children (2F; 13.4±2.7 years) was conducted. Participants listened to syntactically correct and incorrect sentences while magnetoencephalography was recorded, and task-related functional connectivity in the time window and frequency band of interest was determined. Structural connectivity between brain regions was investigated using DTI tractography, and language outcomes were assessed using neuropsychological tests.

Results: An analysis of the syntactic language network (4-7 Hz, 1.2-1.4s) indicated that unlike the typical correlation between left-lateralized functional connectivity and language skill ( p <0.01), good outcome in patients is correlated with bilateral frontal connectivity (p<0.01). Furthermore, patients exhibit a significant reduction in structural connectivity between the left and right supplementary motor area, compared with controls ( p =0.007), and the bilateral structural connectivity of this region is positively correlated with measures of working memory and information processing ( p =0.036).

Conclusions: The preliminary results suggest that reorganization of functional networks towards bilateral connectivity may support language outcome following early stroke. The supplementary motor area’s role in coordination of interhemispheric functions and in information processing may position it as a key structural region in supporting the compensatory reorganization of functional networks underlying language. Ultimately, measures of functional and structural networks may be used as a prognostic tool for language development in pediatric stroke in order to improve long-term outcomes.

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.

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.

The epileptology of GNB5 encephalopathy

Pathogenic variants in GNB5 cause an autosomal recessive neurodevelopmental disorder with neonatal sinus bradycardia. Seizures or epilepsy occurred in 10 of 22 previously reported cases, including 6 children from one family. We delineate the epileptology of GNB5 encephalopathy. Our nine patients, including five new patients, were from seven families. Epileptic spasms were the most frequent seizure type, occurring in eight of nine patients, and began at a median age of 3 months (2 months to 3 years). Focal seizures preceded spasms in three children, with onset at 7 days, 11 days, and 4 months. One child presented with convulsive status epilepticus at 6 months. Three children had burst suppression on electroencephalography (EEG), three had hypsarrhythmia, and one evolved from burst suppression to hypsarrhythmia. Background slowing was present in all after age 3 years. Magnetic resonance imaging (MRI) showed cerebral atrophy in one child and cerebellar atrophy in another. All nine had abnormal development prior to seizure onset and ultimately had profound impairment without regression. Hypotonia was present in all, with contractures developing in two older patients. All individuals had biallelic pathogenic variants in GNB5, predicted by in silico tools to result in protein truncation and loss-of-function. GNB5 developmental and epileptic encephalopathy is characterized by epileptic spasms, focal seizures, and profound impairment.

Feeding and swallowing impairment in children with stroke and unilateral cerebral palsy: a systematic review

AIM

This systematic review targeted frequency estimates of dysphagia (feeding and swallowing problems), related health outcomes, and caregiver burden in children with stroke or unilateral cerebral palsy (CP).

METHOD

Six electronic databases were searched from their inception to November 2017 along with a manual search of eight relevant journals. Two blinded raters assessed abstracts and full articles for eligibility. Discrepancies were resolved by consensus. Accepted articles were evaluated for quality. Data were extracted and analysed descriptively.

RESULTS

Of 1660 abstracts, five met inclusion criteria, of which three focused on stroke and two unilateral CP. Across studies, operational definitions of feeding and swallowing varied. Insufficient details were provided on assessment methods and timing. Reported frequencies of dysphagia ranged from 24.2% to 88.6%. One study reported dysphagia-related health outcomes and none reported caregiver burden.

INTERPRETATION

These results suggest that dysphagia is common in children with stroke and unilateral CP; however, its frequency is yet unknown as is its impact on health and caregiver burden. Availability of a standardized tool to identify dysphagia in these children accurately is a recommended first step to address this evidence gap.

WHAT THIS PAPER ADDS

There is limited data on the incidence of dysphagia after childhood stroke and unilateral cerebral palsy. Available evidence shows reported dysphagia frequencies from 24.2% to 88.6%. Only one study reported on dysphagia-related health outcomes. No study reported on caregiver burden.

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.

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.

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.

Utility of Neurovascular Imaging in Acute Neonatal Arterial Ischemic Stroke

OBJECTIVE

To evaluate the prevalence of magnetic resonance angiography (MRA) findings and clinically characterize neonates with arterial ischemic stroke (AIS) who have abnormal or variable vasculature.

STUDY DESIGN

This was a single-center, retrospective study of patients with neonatal stroke from 1991 to 2012. We reviewed charts and neuroimaging, including MRA, in neonates with AIS. Clinical data of patients with MRA findings were compared with the control group of neonates with AIS and a normal MRA.

RESULTS

We identified 142 cases of neonatal AIS, of which 81 patients had magnetic resonance imaging and MRA. Among the neonates with arterial neuroimaging, 29 had arterial findings (for a prevalence rate of 20%-35%). The majority of the findings were stenotic or hypoplastic branches. Two patients had presumed carotid artery dissection. Low Apgar scores and the presence of sepsis were significantly (P <.05) more common in neonates with MRA findings.

CONCLUSION

The prevalence of arterial abnormalities or variations in neonatal AIS has been underestimated because neurovascular imaging is often not performed. We recommend an MRA for neonates with AIS, particularly those who have low Apgar scores and/or sepsis, to rule out a vasculopathy that may warrant therapeutic intervention.

Phenotypic and genotypic spectrum of congenital disorders of glycosylation type I and type II

BACKGROUND

Congenital disorders of glycosylation (CDG) are inborn defects of glycan metabolism. They are multisystem disorders. Analysis of transferrin isoforms is applied as a screening test for CDG type I (CDG-I) and type II (CDG-II). We performed a retrospective cohort study to determine spectrum of phenotype and genotype and prevalence of the different subtypes of CDG-I and CDG-II.

MATERIAL AND METHODS

All patients with CDG-I and CDG-II evaluated in our institution's Metabolic Genetics Clinics were included. Electronic and paper patient charts were reviewed. We set-up a high performance liquid chromatography transferrin isoelectric focusing (TIEF) method to measure transferrin isoforms in our Institution. We reviewed the literature for the rare CDG-I and CDG-II subtypes seen in our Institution.

RESULTS

Fifteen patients were included: 9 with PMM2-CDG and 6 with non-PMM2-CDG (one ALG3-CDG, one ALG9-CDG, two ALG11-CDG, one MPDU1-CDG and one ATP6V0A2-CDG). All patients with PMM2-CDG and 5 patients with non-PMM2-CDG showed abnormal TIEF suggestive of CDG-I or CDG-II pattern. In all patients, molecular diagnosis was confirmed either by single gene testing, targeted next generation sequencing for CDG genes, or by whole exome sequencing.

CONCLUSION

We report 15 new patients with CDG-I and CDG-II. Whole exome sequencing will likely identify more patients with normal TIEF and expand the phenotypic spectrum of CDG-I and CDG-II.

A pediatric institutional acute stroke protocol improves timely access to stroke treatment

AIM

We aimed to evaluate whether an institutional acute stroke protocol (ASP) could accelerate the diagnosis and secondary treatment of pediatric stroke.

METHOD

We initiated an ASP in 2005. We compared 209 children (125 males, 84 females; median age 4.8y, interquartile range [IQR] 1.2-9.3y, range 0.09-17.7y) diagnosed with arterial ischemic stroke 'pre-protocol' (1992-2004) to 112 children (60 males, 52 females; median age 5.8y, IQR 1.0-11.4y, range 0.08-17.7y) diagnosed 'post-protocol' (2005-2012) for time-to-diagnosis, mode of diagnostic imaging, and time-to-treatment with antithrombotic medication (aspirin or anticoagulants).

RESULTS

Overall, the interval from symptom onset to diagnosis was similar post-protocol compared to pre-protocol (20.3 vs 22.7h; p=0.109), although mild strokes (Pediatric National Institute of Health Stroke Scale [PedNIHSS] 0-4), were diagnosed faster post-protocol (12.1 vs 36.3h; p=0.003). Magnetic resonance imaging (MRI) was the initial diagnostic modality more often post-protocol (25% vs 1.4%; p<0.001). Initial MRI was more accurate for diagnosing stroke than initial CT (100% vs 47%; p<0.001) with similar time-to-diagnosis. The proportion of children receiving antithrombotic medication within 24 hours doubled in the post-protocol period (83% vs 36%; p<0.001).

INTERPRETATION

A pediatric ASP accelerated time-to-treatment, time-to-diagnosis in children with subtle strokes, and increased MRI as initial imaging, reducing the need for computed tomography. Implementing optimized ASPs can facilitate more timely access to diagnosis and management of children with acute stroke.

Thrombectomy for Acute Stroke in Childhood: A Case Report, Literature Review, and Recommendations

The updated American Heart Association/American Stroke Association guidelines include recommendation for thrombectomy in certain adult stroke cases. The safety and efficacy of thrombectomy in children are unknown. An 8-year-old girl experienced acute stroke symptoms on two occasions while therapeutically anticoagulated on Novalung. Computed tomography scans showed proximal vessel thrombi, which were retrieved using a Trevo device without hemorrhagic complications. Postprocedural assessment found respective decreases in the National Institutes of Health Stroke Scale score from 10 to 4 and 12 to 7. The indications for treatment and early benefits observed in our case are consistent with other pediatric thrombectomy cases reported. However, publication bias and the heterogeneity of reported cases prevent drawing conclusions about the safety and efficacy of thrombectomy in children. Anticipating that updates to adult stroke guidelines would likely incite stroke providers to consider thrombectomy in children, our institution developed guidelines for thrombectomy before the index patient. Establishing institutional guidelines before considering thrombectomy in children may optimize patient safety.

Association Between Prolonged Seizures and Malignant Middle Cerebral Artery Infarction in Children With Acute Ischemic Stroke

BACKGROUND

Malignant middle cerebral artery infarct syndrome is a potentially fatal complication of stroke that is poorly understood in children. We studied the frequency, associated characteristics, and outcomes of this condition in children.

METHODS

Children, aged two months to 18 years with acute middle cerebral artery infarct diagnosed at our center between January 2005 and December 2012 were studied. Associations with malignant middle cerebral artery infarct syndrome were sought, including age, seizures, neurological deficit severity (Pediatric National Institute of Health Stroke Severity Score), stroke etiology, fever, blood pressure, blood glucose, infarct location, infarct volume (modified pediatric Alberta Stroke Program Early Computed Tomography Score), and arterial occlusion. Death and neurological outcomes were determined.

RESULTS

Among 66 children with middle cerebral artery stroke, 12 (18%) developed malignant middle cerebral artery infarct syndrome, fatal in three. Prolonged seizures during the first 24 hours (odds ratio, 25.51; 95% confidence interval, 3.10 to 334.81; P = 0.005) and a higher Pediatric National Institute of Health Stroke Severity Score (odds ratio, 1.22; 95% confidence interval, 1.08 to 1.45; P = 0.006) were independently associated with malignant middle cerebral artery infarct syndrome. All children aged greater than two years with a Pediatric National Institute of Health Stroke Severity Score ≥8 and initial seizures ≥5 minutes duration developed malignant middle cerebral artery infarct syndrome (100%).

CONCLUSIONS

Malignant middle cerebral artery infarct syndrome affects nearly one in five children with acute middle cerebral artery stroke. Children with higher Pediatric National Institute of Health Stroke Severity Scores and prolonged initial seizures are at greatly increased risk for malignant middle cerebral artery infarct syndrome. Children with middle cerebral artery infarcts warrant intensive neuroprotective management and close monitoring to enable early referral for hemicraniectomy surgery.

Prognostication Value of Descending Corticospinal Tract DWI Signal in Neonatal Cerebral Sinovenous Thrombosis

BACKGROUND

Descending corticospinal tract diffusion-weighted magnetic resonance imaging (MRI) signal is predictive of poor motor outcome in neonatal and childhood arterial ischemic stroke. However, descending corticospinal tract diffusion-weighted MRI signal has not been documented in the setting of cerebral sinovenous thrombosis, and its role is not understood.

OBJECTIVE

We describe a neonate with cerebral sinovenous thrombosis, extensive diffusion restriction, and bilateral descending corticospinal tract diffusion-weighted MRI signal on MRI of the brain. We discuss the underlying mechanisms and implications of these findings in venous ischemia.

CONCLUSION

The prognostic value of descending corticospinal tract diffusion-weighted MRI signal differs when observed in cerebral sinovenous thrombosis from when observed in arterial ischemic stroke. Consequently, caution should be exercised in using descending corticospinal tract diffusion-weighted MRI signal to predict outcome in children with cerebral sinovenous thrombosis.

Abstract WMP105: Quantitative Assessment of Cerebrovascular Reactivity in Paediatric Moyamoya

Background: Moyamoya disease is a progressive steno-occlusive arteriopathy that causes recurrent ischaemic events and neurological decline. Cerebrovascular reactivity (CVR) is an indicator of tissue level perfusion impairment and stroke risk. Quantitative BOLD MRI using carbon dioxide as a vasoactive stimulus has been validated in adults and region of CVR abnormality shown to be concordant with angiographic region of abnormality. However the evidence in paediatric literature remains scarce and mainly refers to the use of targeted-controlled delivery of CO2 which has limited utility in the paediatric population.

Objective: To examine whether hypercapnic challenge BOLD CVR using endogenous CO2 in the awake (breath-hold [BH]) and sleep (general anaesthetic [GA]) state in children is reliable and repeatable. We also sought to explore whether regional abnormalities of CVR using these techniques were concordant with angiographic regions of abnormality.

Method: Consecutive children with angiographic confirmation of MM had BH or GA CVR studies. All repeat studies - conducted on the same day in the same MRI session - were assessed for reliability and repeatability of qualitative measures of CVR.

Results: Thirty seven children (16 male; median age MM diagnosis 8.61 years, range 0.6 - 16.7; median age at CVR 10.7 years, range 1.08-17.7) had CVR studies. Children who had a CVR study under GA were significantly younger at diagnosis of MM (mean age 7.4 years, range .67-16.58) compared to those studied using BH (mean age 10.47 years, range .83-15.58). CVR region of abnormality was concordant with region of angiographic abnormality. Twenty nine had repeat studies (14 GA, 15 BH). Intraclass correlation was fair (0.783, 95% confidence interval .534-.899) to excellent (.910, 95% confidence interval .577-.908) and agreement between repeat measures good.

Conclusion: Qualitative measures of CVR using general anaesthetic and breath-hold techniques are reliable, repeatable and interpretable for use in clinical practice. However standardization of protocols would allow more reliable application of these tools for assessment of ischaemic risk in childhood cerebrovascular disease.

Abstract WP411: Anatomical Venous Variants and Physiological Adaptive Changes in Children With Cerebral Sinovenous Thrombosis

Objective: Cerebral venous vessels a have unique morphology. No information is available regarding the presence of anomalous venous structure and related consequences in children. We aim to describe the frequency of anatomical variants (persistent fetal structures), and physiological changes (collateralization), in children with CSVT. We hypothesize that these variations impact in the re-distribution of venous drainage in the presence of stressors such as anemia or dehydration.

Methods: We retrospectively reviewed children (1 month - 18 years), with CSVT over 5 years (Jan 2008 - Dec 2013). We excluded children with arterial ischemic stroke, trauma, compressive intracranial lesions and systemic venous hypertension. We reviewed for symptoms at presentation, risk factors, sinus involved, thrombus location, parenchymal lesions, antithrombotic therapy, outcome using the Paediatric Stroke Outcome Measure (PSOM) and recanalization rate at last follow-up. MRV/CTV reports were evaluated for anatomical variants and physiological changes in the venous systems.

Results: Thirty-four children were identified. 17 boys (50%), with mean age at CSVT of 13.5 years (0.2 -17.6 years). 11 had anatomical variations (32%) vs. 23 (68%) with typical anatomy. These included 6 (54%) children with abnormal sinus morphology (hypoplasia/absence of a major dural sinus), 3 (27%) children with persistent fetal structures and 6 (54%) with prominent collateralization. Most of the cases had > 1 anatomical variant together. Signs of increased intracranial pressure were seen more frequently in children with anatomical variants 7(63%) than in those without variants 7(30%), although not statistically significant. 5 children (45%) with anatomical variations had brain parenchymal involvement vs. 5 (22%) with normal anatomy. Mean recanalization rate was the same between the two groups: 10(90%) at mean follow-up of 5.5mo (3 - 9mo) in the variant vs. 22(96%) at 4.2mo (1.5 - 9mo) in the normal anatomy group.

Conclusion: The presence of anatomical variants in the cerebral venous structures may be associated with a more severe initial presentation in children with CSVT. Variant venous anatomy may be less efficient in compensating for the obstruction to venous outflow due to thrombosis.

Abstract WP412: Neurovascular Imaging is not Always Normal in Neonatal Arterial Ischemic Stroke

Background: Neonatal arterial ischemic stroke (AIS) is the most common pediatric stroke occurring in more than 1/4000 live births with a risk of recurrence of less than 1%. The presence of an arteriopathy is associated with high risk of recurrence in childhood stroke. However, The prevalence and risk factors of an arteriopathy in neonatal stroke are not known.

Objective: We sought to characterize the subgroup of neonates with AIS who have abnormal vasculature.

Patients and Methods: This is a single center retrospective case-control study of patients with neonatal stroke from 1991-2012. Charts were reviewed for neonates with AIS and neuroimaging that included vascular imaging (MRI/MRA). Clinical data of patients with abnormal MRA was compared to the control group of neonates with AIS but a normal MRA.

Results: A total of 142 cases of neonatal AIS were identified of which 82 patients had MRI/MRA. Among the neonates with vascular neuroimaging, 30 had abnormal vessels (minimum prevalence rate of 36%). The majority of vascular abnormalities were stenotic or hypoplastic branches. Two patients (7%) had dissection. Young maternal age, positive maternal GBS, C-section delivery, low APGAR scores, low Hgb, and cardiac defects were significantly (p < 0.05) more common in neonates with abnormal vessels.

Conclusion: Neurovascular imaging is challenging in neonates so often not performed. However, we recommend that an MRA to be performed in neonates with AIS who have any of the risk factors identified in this study. Early diagnosis of their vasculopathy may change their stroke management and impact outcome.