Neurological Complications of Sturge-Weber Syndrome: Current Status and Unmet Needs

OBJECTIVE

We aimed to identify the current status and major unmet needs in the management of neurological complications in Sturge-Weber syndrome.

METHODS

An expert panel consisting of neurologists convened during the Sturge-Weber Foundation Clinical Care Network conference in September 2018. Literature regarding current treatment strategies for neurological complications was reviewed.

RESULTS

Although strong evidence-based standards are lacking, the implementation of consensus-based standards of care and outcome measures to be shared across all Sturge-Weber Foundation Clinical Care Network Centers are needed. Each patient with Sturge-Weber syndrome should have an individualized seizure action plan. There is a need to determine the appropriate abortive and preventive treatment of migraine headaches in Sturge-Weber syndrome. Likewise, a better understanding and better diagnostic modalities and treatments are needed for stroke-like episodes. As behavioral problems are common, the appropriate screening tools for mental illnesses and the timing for screening should be established. Brain magnetic resonance imaging (MRI) preferably done after age one year is the primary imaging modality of choice to establish the diagnosis, although advances in MRI techniques can improve presymptomatic diagnosis to identify patients eligible for preventive drug trials.

CONCLUSION

We identified the unmet needs in the management of neurological complications in Sturge-Weber syndrome. We define a minimum standard brain MRI protocol to be used by Sturge-Weber syndrome centers. Future multicenter clinical trials on specific treatments of Sturge-Weber syndrome-associated neurological complications are needed. An improved national clinical database is critically needed to understand its natural course, and for retrospective and prospective measures of treatment efficacy.

What is the Role of Mechanical Thrombectomy in Childhood Stroke?

BACKGROUND

Like adults, most children have lifelong morbidity after stroke. Revascularization therapies such as intravenous tissue plasminogen activator and mechanical thrombectomy may be options to decrease this morbidity in selected children, although currently there are no evidence-based recommendations to guide treatment. The utility and safety of mechanical thrombectomy in childhood stroke is unknown because of the lack of safety trials, case-controlled trials, and comprehensive retrospective studies. As such, the current rationale for the use of mechanical thrombectomy in childhood is based on extrapolation from adult experience, as well as consensus at individual institutions with many centers deciding care on a case-by-case basis. Nevertheless, the increasing use of recanalization therapies in appropriately selected adults with acute arterial ischemic stroke has led to an increase in consideration and use in childhood, and there are enough case reports and series, as well as experience, to suggest that some children with large vessel occlusion will likely benefit.

METHODS

We reviewed current literature regarding mechanical thrombectomy in childhood.

RESULTS

There are differences between pediatric and adult stroke which may impact safety, efficacy, and individual decision-making, including patient size, pathophysiology of stroke, deficit, experience, and lack of data regarding natural history of stroke in children.

CONCLUSIONS

Hospitals planning to perform mechanical thrombectomy in children should establish local procedures and guidelines for considering thrombectomy. In our experience, care is best provided through multidisciplinary teams including a pediatric vascular neurologist, neurointerventionalist with pediatric experience, and pediatric neurocritical care.

Childhood Moyamoya: Looking Back to the Future

Moyamoya is a chronic, progressive steno-occlusive arteriopathy that typically affects the anterior circulation arteries of the circle of Willis. A network of deep thalamoperforating and lenticulostriate collaterals develop to by-pass the occlusion giving rise to the characteristic angiographic "puff of smoke" appearance. Moyamoya confers a lifelong risk of stroke and neurological demise, with peak age of presentation in childhood ranging between five and 10 years. Moyamoya disease refers to patients who do not have a comorbid condition, whereas moyamoya syndrome refers to patients in whom moyamoya occurs in association with an acquired or inherited disorder such as sickle cell disease, neurofibromatosis type-1 or trisomy 21. The incidence of moyamoya disease and moyamoya syndrome demonstrates geographic and ethnic variation, with a predominance of moyamoya disease in East-Asian populations. Antiplatelet therapy and surgical revascularization procedures are the mainstay of management, as there are no available treatments to slow the progression of the arteriopathy. Future research is required to address the major gaps that remain in our understanding of the pathologic basis, optimal timing for surgery, and determinants of outcome in this high-stroke risk condition of childhood.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The Genetic Landscape of Cerebral Steno-Occlusive Arteriopathy and Stroke in Sickle Cell Anemia

Sickle cell disease (SCD) is one of the most common autosomal recessive diseases in humans, occurring at a frequency of 1 in 365 African-American and 1 in 50 sub-Saharan African births. Despite progress in managing complications of SCD, these remain a major health burden worldwide. Stroke is a common and serious complication of SCD, most often associated with steno-occlusive cerebral arteriopathy, but little is known about its pathogenesis. Transcranial Doppler ultrasonography is currently the only predictive test for future development of stroke in patients with sickle cell anemia and is used to guide preventative treatment. However, transcranial Doppler ultrasonography does not identify all patients at increased risk for stroke, and progressive arteriopathy may occur despite preventative treatment. While sibling studies have shown a strong genetic contribution to the development of steno-occlusive arteriopathy (SOA) in SCD, the only genome-wide association study compared a relatively small cohort of 177 patients with stroke to 335 patients with no history of stroke. This single study detected variants in only 2 genes, ENPP1 and GOLGB1, and only one of these was confirmed in a subsequent independent study. Thus, the underlying genes and pathogenesis of SOA in SCD remain poorly understood, greatly limiting the ability to develop more effective preventive therapies. Dissecting the molecular causes of stroke in SCD will provide valuable information that can be used to better prevent stroke, stratify risk of SOA, and optimize personalized medicine approaches.

Evaluation and Acute Management of Ischemic Stroke in Infants and Children

PURPOSE OF REVIEW

This article provides an overview of stroke in neonates, infants, and children.

RECENT FINDINGS

Arterial ischemic stroke and cerebral venous sinus thrombosis are increasingly recognized in childhood as important causes of lifelong morbidity and mortality. Diagnosis of arterial ischemic stroke is frequently delayed, as acute neurologic deficits can be challenging to detect in the young child, and stroke is often not considered in the differential diagnosis. Neurologic sequelae following stroke are common, and strategies to minimize stroke size and optimize recovery are being developed. Recurrent arterial ischemic stroke is not uncommon, particularly in children with cerebral arteriopathy. Cerebral venous sinus thrombosis causes obstruction of venous outflow leading to venous infarcts. Complications include hemorrhagic conversion of infarcts and increased intracranial pressure. Without treatment, thrombus extension with increased symptoms is common. Robust guidelines of care that exist for adults do not exist for children, particularly for children with arterial ischemic stroke.

SUMMARY

The approach to stroke in infants and children can be informed by clinical experience in pediatric stroke and cerebral venous sinus thrombosis, the extensive literature on pediatric thrombosis, and extrapolation from data from adult patients.

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

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

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

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

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

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

Pathways for Neuroimaging of Childhood Stroke

BACKGROUND

The purpose of this article is to aid practitioners in choosing appropriate neuroimaging for children who present with symptoms that could be caused by stroke.

METHODS

The Writing Group members participated in one or more pediatric stroke neuroimaging symposiums hosted by the Stroke Imaging Laboratory for Children housed at the Hospital for Sick Children in Toronto, Ontario, Canada. Through collaboration, literature review, and discussion among child neurologists with expertise diagnosing and treating childhood stroke and pediatric neuroradiologists and neuroradiologists with expertise in pediatric neurovascular disease, suggested imaging protocols are presented for children with suspected stroke syndromes including arterial ischemic stroke, cerebral sinovenous thrombosis, and hemorrhagic stroke.

RESULTS

This article presents information about the epidemiology and classification of childhood stroke with definitions based on the National Institutes of Health Common Data Elements. The role of imaging for the diagnosis of childhood stroke is examined in depth, with separate sections for arterial ischemic stroke, cerebral sinovenous thrombosis, and hemorrhagic stroke. Abbreviated neuroimaging protocols for rapid diagnosis are discussed. The Writing Group provides suggestions for optimal neuroimaging investigation of various stroke types in the acute setting and suggestions for follow-up neuroimaging. Advanced sequences such as diffusion tensor imaging, perfusion imaging, and vessel wall imaging are also discussed.

CONCLUSIONS

This article provides protocols for the imaging of children who present with suspected stroke.

Inter-Rater Reliability of the CASCADE Criteria: Challenges in Classifying Arteriopathies

BACKGROUND AND PURPOSE

There are limited data about the reliability of subtype classification in childhood arterial ischemic stroke, an issue that prompted the IPSS (International Pediatric Stroke Study) to develop the CASCADE criteria (Childhood AIS Standardized Classification and Diagnostic Evaluation). Our purpose was to determine the CASCADE criteria's reliability in a population of children with stroke.

METHODS

Eight raters from the IPSS reviewed neuroimaging and clinical records of 64 cases (16 cases each) randomly selected from a prospectively collected cohort of 113 children with arterial ischemic stroke and classified them using the CASCADE criteria. Clinical data abstracted included history of present illness, risk factors, and acute imaging. Agreement among raters was measured by unweighted κ statistic.

RESULTS

The CASCADE criteria demonstrated a moderate inter-rater reliability, with an overall κ statistic of 0.53 (95% confidence interval [CI]=0.39-0.67). Cardioembolic and bilateral cerebral arteriopathy subtypes had much higher agreement (κ=0.84; 95% CI=0.70-0.99; and κ=0.90; 95% CI=0.71-1.00, respectively) than cases of aortic/cervical arteriopathy (κ=0.36; 95% CI=0.01-0.71), unilateral focal cerebral arteriopathy of childhood (FCA; κ=0.49; 95% CI=0.23-0.76), and small vessel arteriopathy of childhood (κ=-0.012; 95% CI=-0.04 to 0.01).

CONCLUSIONS

The CASCADE criteria have moderate reliability when used by trained and experienced raters, which suggests that it can be used for classification in multicenter pediatric stroke studies. However, the moderate reliability of the arteriopathic subtypes suggests that further refinement is needed for defining subtypes. Such revisions may reduce the variability in the literature describing risk factors, recurrence, and outcomes associated with childhood arteriopathy.

Vascular disease

The child presenting with possible sentinel transient ischemic event or stroke requires prompt diagnosis so that strategies to limit injury and prevent recurrent stroke can be instituted. Cerebral arteriopathy is a potent risk factor for arterial ischemic stroke in childhood. Though acute imaging study in the setting of possible stroke is often a head computed tomography, when possible magnetic resonance imaging (MRI) is recommended as the first-line study as confirmation and imaging evaluation of ischemic stroke will typically require MRI. The MRI scanning approach should include diffusion-weighted imaging (DWI) early in the sequence order, since normal DWI excludes acute infarct with rare exception. In most cases, arterial imaging with time-of-flight (TOF) magnetic resonance angiography (MRA) is warranted. Dedicated MRA may not be possible in the acute setting, but should be pursued as promptly as possible, particularly in the child with findings and history suggestive of arteriopathy, given the high risk of recurrent stroke in these children. MRA can overestimate the degree of arterial compromise due to complex/turbulent flow, and be insensitive to subtle vessel irregularity due to resolution and complex flow. In cases with high imaging suspicion for dissection despite normal MRA findings, catheter angiogram is indicated. A thoughtful, stepwise approach to arterial neuroimaging is critical to optimize diagnosis, treatment, and primary and secondary prevention of childhood stroke.

Added Value of Vessel Wall Magnetic Resonance Imaging in the Differentiation of Moyamoya Vasculopathies in a Non-Asian Cohort

BACKGROUND AND PURPOSE

Although studies have evaluated the differential imaging of moyamoya disease and atherosclerosis, none have investigated the added value of vessel wall magnetic resonance imaging (MRI). This study evaluates the added diagnostic value of vessel wall MRI in differentiating moyamoya disease, atherosclerotic-moyamoya syndrome (A-MMS), and vasculitic-MMS (V-MMS) with a multicontrast protocol.

METHODS

We retrospectively reviewed the carotid artery territories of patients with clinically defined vasculopathies (moyamoya disease, atherosclerosis, and vasculitis) and steno-occlusive intracranial carotid disease. Two neuroradiologists, blinded to clinical data reviewed the luminal imaging of each carotid, evaluating collateral extent and making a presumed diagnosis with diagnostic confidence. After 3 weeks, the 2 readers reviewed the luminal imaging+vessel wall MRI for the presence, pattern and intensity of postcontrast enhancement, T2 signal characteristics, pattern of involvement, and presumed diagnosis and confidence.

RESULTS

Ten A-MMS, 3 V-MMS, and 8 moyamoya disease cases with 38 affected carotid segments were included. There was significant improvement in diagnostic accuracy with luminal imaging+vessel wall MRI when compared with luminal imaging (87% versus 32%, P<0.001). The most common vessel wall MRI findings for moyamoya disease were nonenhancing, nonremodeling lesions without T2 heterogeneity; for A-MMS eccentric, remodeling, and T2 heterogeneous lesions with mild/moderate and homogeneous/heterogeneous enhancement; and for V-MMS concentric lesions with homogeneous, moderate enhancement. Inter-reader agreement was moderate to substantial for all vessel wall MRI characteristics (κ=0.46-0.86) and fair for collateral grading (κ=0.35). There was 11% inter-reader agreement for diagnosis on luminal imaging when compared with 82% for luminal imaging+vessel wall MRI (P<0.001).

CONCLUSIONS

Vessel wall MRI can significantly improve the differentiation of moyamoya vasculopathies when combined with traditional imaging techniques.

Varicella Zoster Virus: A Common Cause of Stroke in Children and Adults

BACKGROUND

Varicella zoster virus (VZV) is a neurotropic, exclusively human herpesvirus. Primary infection causes varicella (chickenpox), after which the virus becomes latent in ganglionic neurons along the entire neuraxis. As cell-mediated immunity to VZV declines with advancing age and immunosuppression, VZV reactivates to produce zoster (shingles). One of the most serious complications of zoster is VZV vasculopathy.

METHODS

We reviewed recent studies of stroke associated with varicella and zoster, how VZV vasculopathy is verified virologically, vaccination to prevent varicella and immunization to prevent zoster, and VZV in giant cell arteritis (GCA).

FINDINGS

We report recent epidemiological studies revealing an increased risk of stroke after zoster; the clinical, laboratory, and imaging features of VZV vasculopathy; that VZV vasculopathy is confirmed by the presence of either VZV DNA or anti-VZV IgG antibody in cerebrospinal fluid; special features of VZV vasculopathy in children; vaccination to prevent varicella and immunization to prevent zoster; and the latest evidence linking VZV to GCA.

CONCLUSION

In children and adults, VZV is a common cause of stroke.

Preparing for a "Pediatric Stroke Alert"

BACKGROUND

Childhood arterial ischemic stroke is an important cause of morbidity and mortality in children. Hyperacute treatment strategies remain controversial and challenging, especially in the setting of increasingly proven medical and endovascular options in adults. Although national and international pediatric guidelines have given initial direction about acute therapy and management, pediatric centers have traditionally lacked the infrastructure to triage, diagnose, and treat childhood arterial ischemic stroke quickly.

METHODS

In the past 10 years, researchers in the International Pediatric Stroke Study and Thrombolysis in Pediatric Stroke study have initiated early strategies for establishing pediatric specific stroke alerts.

RESULTS

We review the rationale, process and components necessary for establishing a pediatric stroke alert.

CONCLUSION

Development of pediatric stroke protocols and pathways, with evidence-based acute management strategies and supportive care where possible, facilitates the evaluation, management, and treatment of an acute pediatric stroke.

Guidelines for Urgent Management of Stroke in Children

Stroke in children carries lasting morbidity. Once recognized, it is important to evaluate and treat children with acute stroke efficiently and accurately. All children should receive neuroprotective measures. It is reasonable to consider treatment with advanced thrombolytic and endovascular agents. Delivery of such care requires purposeful institutional planning and organization in pediatric acute care centers. Primary stroke centers established for adults provide an example of the multidisciplinary approach that can be applied to the evaluation and treatment of children who present with acute stroke. The organizational infrastructure of these centers can be employed and adapted for treatment of children with acute stroke. It is likely that care for children with acute stroke can best be delivered by regional pediatric primary stroke centers dedicated to the care of children with pediatric stroke.

Herpesvirus Infections and Childhood Arterial Ischemic Stroke: Results of the VIPS Study

BACKGROUND

Epidemiological studies demonstrate that childhood infections, including varicella zoster virus, are associated with an increased risk of arterial ischemic stroke (AIS). Other herpesviruses have been linked to childhood AIS in case reports. We sought to determine whether herpesvirus infections, which are potentially treatable, increase the risk of childhood AIS.

METHODS AND RESULTS

We enrolled 326 centrally confirmed cases of AIS and 115 stroke-free controls with trauma (29 days to 18 years of age) with acute blood samples (≤3 weeks after stroke/trauma); cases had convalescent samples (7-28 days later) when feasible. Samples were tested by commercial enzyme-linked immunosorbent assay kits for immunoglobulin M/immunoglobulin G antibodies to herpes simplex virus 1 and 2, cytomegalovirus, Epstein-Barr virus, and varicella zoster virus. An algorithm developed a priori classified serological evidence of past and acute herpesvirus infection as dichotomous variables. The median (quartiles) age was 7.7 (3.1-14.3) years for cases and 10.7 (6.9-13.2) years for controls (P=0.03). Serological evidence of past infection did not differ between cases and controls. However, serological evidence of acute herpesvirus infection doubled the odds of childhood AIS, even after adjusting for age, race, and socioeconomic status (odds ratio, 2.2; 95% confidence interval, 1.2-4.0; P=0.007). Among 187 cases with acute and convalescent blood samples, 85 (45%) showed evidence of acute herpesvirus infection; herpes simplex virus 1 was found most often. Most infections were asymptomatic.

CONCLUSIONS

Herpesviruses may act as a trigger for childhood AIS, even if the infection is subclinical. Antivirals like acyclovir might have a role in the prevention of recurrent stroke if further studies confirm a causal relationship.

Abstract T P378: Factors Associated with the Presentation of Moyamoya in Childhood

Introduction: Moyamoya accounts for approximately one fifth of cerebral arteriopathies in children presenting with acute stroke, however often is not diagnosed until stroke occurs, even in higher risk populations and often despite a history of transient ischemic attacks (TIA’s). The surgical management and outcome are well reported, but limited information exists regarding signs and symptoms preceding diagnosis. This study was undertaken to better define which groups of children are at risk for moyamoya and how these children present.

Methods: With IRB approval, the charts of all patients with a diagnosis of moyamoya cared for between Jan 1, 1997 - Sept 26, 2013 were reviewed.

Results: Of 54 children with moyamoya, the mean age at presentation was 7 ½ years. 56% were female. 32 (59 %) had predisposing medical conditions associated with moyamoya. 17 (31%) were of Asian descent. Only 11 children (20%) had no underlying predisposing condition identified, of whom 4 had underlying conditions not previously reported in association with moyamoya. 8 patients (15%) were Native American. 38 (70%) had a history of transient ischemic attacks. 26 (48%) presented with acute stroke, of whom ¾ had left and ¼ had right hemisphere strokes. 52% had a history of headache.

Discussion: The mean age and female predominance in this series are consistent with previous reports. Most children with moyamoya in this series had an underlying predisposing condition, compared with other US series, where almost half had no predisposing condition identified. 15% of children in this series are American Indian or Alaska Native, compared with 1.3% of all patients served at this institution. In this series, fewer children (48% vs 68%) presented with stroke, more (70% vs 43%) had a history of TIAs, and more (52% vs 22%) had a history of headaches than in previous reports. In addition, the Native American population may be at higher risk of moyamoya than previously recognized.