Myopericytoma of the axillary artery in a 4-year-old girl presenting with stroke and subsequent progression of micro-isolated lesion

A 4-year-old girl presented with complaints of transient speech disorder and left-sided weakness. Magnetic resonance imaging revealed multiple strokes, computed tomography showed a right axillary artery aneurysm of 40 mm, and an angiogram indicated retrograde embolism. She underwent aneurysm resection and reconstruction with a saphenous vein graft. Two years after surgery, a mass lesion occurred in the native artery on the proximal side of the prior surgical anastomosis. Surgical resection and reconstruction were performed. An isolated 1-mm diameter lesion was found in the retrospectively reviewed completion angiogram from the initial surgery, which was the origin of the subsequent progressive lesion. The pathological examination, including after the initial surgery, revealed a myopericytoma.

Cerebral arteriopathies of childhood and stroke - A focus on systemic arteriopathies and pediatric fibromuscular dysplasia (FMD)

Systemic vascular involvement in children with cerebral arteriopathies is increasingly recognized and often highly morbid. Fibromuscular dysplasia (FMD) represents a cerebral arteriopathy with systemic involvement, commonly affecting the renal and carotid arteries. In adults, FMD diagnosis and classification typically relies on angiographic features, like the 'string-of-beads' appearance, following exclusion of other diseases. Pediatric FMD (pFMD) is considered equivalent to adult FMD although robust evidence for similarities is lacking. We conducted a comprehensive literature review on pFMD and revealed inherent differences between pediatric and adult-onset FMD across various domains including epidemiology, natural history, histopathophysiology, clinical, and radiological features. Although focal arterial lesions are often described in children with FMD, the radiological appearance of 'string-of-beads' is highly nonspecific in children. Furthermore, children predominantly exhibit intimal-type fibroplasia, common in other childhood monogenic arteriopathies. Our findings lend support to the notion that pFMD broadly reflects an undefined heterogenous group of monogenic systemic medium-or-large vessel steno-occlusive arteriopathies rather than a single entity. Recognizing the challenges in categorizing complex morphologies of cerebral arteriopathy using current classifications, we propose a novel term for describing children with cerebral and systemic vascular involvement: 'cerebral and systemic arteriopathy of childhood' (CSA-c). This term aims to streamline patient categorization and, when coupled with advanced vascular imaging and high-throughput genomics, will enhance our comprehension of etiology, and accelerate mechanism-targeted therapeutic developments. Lastly, in light of the high morbidity in children with cerebral and systemic arteriopathies, we suggest that investigating for systemic vascular involvement is important in children with cerebral arteriopathies.

Cerebral Infarction and Recovery in a 12-Year-Old Child With Intracranial Fibromuscular Dysplasia

Fibromuscular dysplasia (FMD) is a congenital vascular anomaly resulting in arterial stenosis and weakening of typically medium-sized arteries. It is a noninflammatory, nonatherosclerotic arterial disease that affects most commonly the renal and internal carotid arteries, but intracranial FMD in the pediatric population is very rare. We report a young age-onset ischemic stroke patient with FMD affecting the middle cerebral artery (MCA). A 14-year-old boy was admitted with left-side weakness during physical education at school. The brain magnetic resonance (MR) imaging revealed an acute ischemic stroke in the right basal ganglia and internal capsule, while the MR angiogram showed segmental intraluminal stenosis in the left proximal MCA. The transfemoral angiography revealed the pathognomonic sign of a "string of beads" at the proximal MCA area. The clinical course was stable, and the boy gradually recovered from the motor weakness of his arm and leg. FMD should be considered as a potential cause of pediatric stroke.

Childhood Cerebral Vasculitis : A Multidisciplinary Approach

Cerebral vasculitis is increasingly recognized as a common cause of pediatric arterial stroke. It can present with focal neurological deficits, psychiatric manifestations, seizures, and encephalopathy. The etiopathogenesis of childhood cerebral vasculitis (CCV) is multifactorial, making an inclusive classification challenging. In this review, we describe the common and uncommon CCV with a comprehensive discussion of etiopathogenesis, the role of various imaging modalities, and advanced techniques in diagnosing CCV. We also highlight the implications of relevant clinical, laboratory, and genetic findings to reach the final diagnosis. Based on the clinicoradiological findings, a stepwise diagnostic approach is proposed to facilitate CCV diagnosis and rule out potential mimics. Identification of key clinical manifestations, pertinent blood and cerebrospinal fluid results, and evaluation of central nervous system vessels for common and disease-specific findings will be emphasized. We discuss the role of magnetic resonance imaging, MR angiography, and vessel wall imaging as the imaging investigation of choice, and reservation of catheter angiography as a problem-solving tool. We emphasize the utility of brain and leptomeningeal biopsy for diagnosis and exclusion of imitators and masqueraders.

Why Would a Child Have a Stroke?

Identifying the etiology of childhood arterial ischemic stroke helps prevent stroke recurrence. In addition, stroke may herald a serious underlying condition requiring treatment, such as acquired heart disease, malignancy, or autoimmune disorder. Evidence-based guidelines exist for adults to identify and treat common risk factors for primary and secondary stroke, including hypertension, diabetes, elevated lipids, atrial fibrillation, and sleep apnea, which are rarely relevant in children. However, guidelines do not exist in pediatrics. Identifying the cause of childhood stroke may be straightforward or may require extensive clinical and neuroimaging expertise, serial evaluations, and reassessment based on the evolving clinical picture. Risk factors may be present but not necessarily causative, or not causative until a triggering event such as infection or anemia occurs. Herein, we describe strategies to determine stroke etiology, including challenges and potential pitfalls.

Incidence, kinetics, and risk factors for intra- and extracranial cerebral arteriopathies in a newborn sickle cell disease cohort early assessed by transcranial and cervical color Doppler ultrasound

The risk of stroke in children with sickle cell disease (SCD) is detected by abnormal intracranial arterial time-averaged mean of maximum velocities (TAMVs ≥200 cm/s). Recently, extracranial internal carotid artery (eICA) arteriopathy has been reported, and a cross-sectional study showed that eICA-TAMVs ≥160 cm/s are significantly associated with eICA kinkings and stenosis. The cumulative incidence of and predictive risk factors for intracranial arteriopathy are well described in sickle cell anemia (SCA=SS/Sβ0) but are lacking for SC/Sβ+ children, as is the cumulative incidence of eICA arteriopathy. We report a prospective longitudinal cohort study including 493 children with SCD (398 SCA, 95 SC/Sβ+), all assessed by transcranial and cervical color Doppler ultrasound. Cerebral MRI/MRA data were available in 375 children with SCD and neck MRA in 365 children. eICA kinkings were defined as eICA tortuosities on neck MRA, with an internal acute angle between the two adjacent segments <90°. The median follow-up was 10.6 years. The cumulative incidence of kinkings was significantly lower in SC/Sβ+ children than in children with SCA, and no SC/Sβ+ child developed intra- or extracranial stenotic arteriopathy. The 10-year KM estimate of cumulative incidence (95% CI) for eICA-TAMVs ≥160 cm/s revealed its development in the 2nd year of life in children with SCA, reaching a plateau of 17.4% (13.2–21.6%) by about 10 years of age, while the plateau for eICA stenosis was 12.3% (8.3–16.3%). eICA assessment identified 13.5% (9.3–17.7%) patients at risk of stroke who were not detected by transcranial color Doppler ultrasound. We also show, for the first time, that in addition to a congenital origin, eICA kinkings sin patients with SCD can develop progressively with aging as a function of eICA-TAMVs, themselves related to anemia severity. Ongoing hydroxyurea treatment was significantly associated with a lower risk of abnormal intracranial arteriopathy and eICA kinkings. After adjustment with hydroxyurea, baseline low hemoglobin, high reticulocyte, and WBC counts remained independent risk factors for intracranial arteriopathy, while low hemoglobin and SEN β-haplotype number were independent risk factors for extracranial arteriopathy. The association between extracranial arteriopathy and SEN β-haplotype number suggested a genetic link between the ethnic origin and incidence of eICA kinkings. This prospective cohort study shows the importance of systematically assessing the eICA and of recording biological parameters during the 2nd year of life before any intensive therapy to predict the risk of cerebral arteriopathy and treat patients with severe baseline anemia.

Border-Zone Infarction Due to Cerebrovascular Fibromuscular Dysplasia

A 45-year-old male presented with acute-onset left-sided weakness and slurred speech. Non-contrast-enhanced brain magnetic resonance imaging revealed cortical and internal border-zone infarcts compatible with stroke. A survey of ischemic stroke risk factors in young adults excluded coagulopathy, vasculitis, and cardiac disease. Nevertheless, neck-computed tomography angiography revealed a long-segmental narrowing of the right internal carotid artery with wall thickening and a “string-of-beads” appearance suspicious for fibromuscular dysplasia, which was confirmed on further angiography. His clinical condition stabilized after intensive medical therapy. This case demonstrates cerebrovascular fibromuscular dysplasia as a possible cause of ischemic stroke in young adults.

Childhood stroke

Stroke is an important cause of neurological morbidity in children; most survivors have permanent neurological deficits that affect the remainder of their life. Stroke in childhood, the focus of this Primer, is distinguished from perinatal stroke, defined as stroke before 29 days of age, because of its unique pathogenesis reflecting the maternal-fetal unit. Although approximately 15% of strokes in adults are haemorrhagic, half of incident strokes in children are haemorrhagic and half are ischaemic. The causes of childhood stroke are distinct from those in adults. Urgent brain imaging is essential to confirm the stroke diagnosis and guide decisions about hyperacute therapies. Secondary stroke prevention strongly depends on the underlying aetiology. While the past decade has seen substantial advances in paediatric stroke research, the quality of evidence for interventions, such as the rapid reperfusion therapies that have revolutionized arterial ischaemic stroke care in adults, remains low. Substantial time delays in diagnosis and treatment continue to challenge best possible care. Effective primary stroke prevention strategies in children with sickle cell disease represent a major success, yet barriers to implementation persist. The multidisciplinary members of the International Pediatric Stroke Organization are coordinating global efforts to tackle these challenges and improve the outcomes in children with cerebrovascular disease.

Acute StrokeTreatment in Children: Are Adult Guidelines Applicable?

Purpose of this Review

This article provides an overview into acute treatments in stroke which are widely studied and available for adults and their applicability in the pediatric population.

Recent Findings

Arterial ischemic stroke is an important cause of morbidity and mortality in the pediatric population. Neurological deficits and etiologies are age-dependent and more challenging to diagnose than in the adult population. Advancements in imaging and treatment modalities including increased treatment windows in acute stroke have led to improvement in the diagnosis and management of pediatric arterial ischemic disease. Accordingly, hyperacute treatments, such as endovascular therapy, are becoming increasingly available in an attempt to improve outcomes in children.

Summary

Significant scientific and technological advances have transformed the hyperacute treatment of stroke in the recent years, allowing for improvement in the diagnosis and treatment of cerebrovascular pathologies in children. Optimization in the approach, and validation of existing stroke pathways/protocols is expected to further advance acute stroke therapy in pediatric patient care. Given that the lifelong individual, family, and societal burden of acute stroke is likely to be greater than in adults because infants and children surviving stroke live more years with disability, we must be knowledgeable about this pathology and the medical and therapeutic options available for this unique population as detailed in this review.

The clinical and radiological cerebrovascular abnormalities associated with renovascular hypertension in children: a systematic review

Renovascular disease is an important secondary cause of hypertension in childhood. In this cohort, many may have undiagnosed cerebrovascular disease, and some children present acutely with cerebrovascular complications. However, these associations are yet to be defined in the literature.A systematic review of clinical and radiological abnormalities associated with renovascular hypertension in the global pediatric (< 18 years) population. The MEDLINE, Embase, and Google Scholar databases were searched, from database inception to 26 January 2021. Primary articles were unrestricted by study design and geographical location but were limited to those published in English.A total of 303 individuals (median age: 7.6 years [range 10 days-17.9 years]; M:F, 174:129) from 34 studies were included, across 13 countries. Twenty-seven individual cases were published for children with coexisting renovascular hypertension and cerebrovascular disease. Most children had bilateral renal artery stenosis, secondary to fibromuscular dysplasia and had coexisting occlusive cerebrovascular disease. The majority presented with neurological symptoms, and cerebral complication ranged from asymptomatic cerebrovascular stenosis to acute stroke and posterior reversible encephalopathy syndrome. The location or underlying etiology of the renovascular disease did not predict the location or extent of the cerebrovascular disease. The evidence from the cohort studies was limited, as none specifically established a cohort of children with coexisting disease. Furthermore, the conclusions drawn were subjected to considerable bias from the treating clinicians.A prospective cohort of children with renovascular hypertension and cerebrovascular complications should be established so the long-term prognosis and impact of treatment may be better understood.

Timing of procedural interventions in childhood renovascular hypertension

BACKGROUND

Renovascular hypertension (RVHTN) is a rare, often complex condition due to multiple etiologies including congenital stenoses, vasculitides, and fibromuscular dysplasia. Among children with RVHTN who require multiple and escalating medications to control blood pressure, the optimal timing of a procedural intervention involves a balance of numerous factors.

CASE-DIAGNOSIS/TREATMENT

In this presentation of a 1-month-old girl with RVHTN, the treating medical team had to consider multiple factors in the initial management and timing of interventions to treat her underlying cause of RVHTN, including concerns for kidney health, degree of hypertension, age and size of the patient, and potential methods of procedural intervention. Initially, she was treated conservatively until concern for poor renal growth arose and a durable surgical intervention was thought feasible and safe.

CONCLUSION

The evidence regarding the timing of non-medical interventions in pediatric RVHTN is limited. Considerations should include patient age, size, disease severity, comorbid conditions, and degree of medical management required to maintain safe blood pressures that allow for growth and reverse cardiac damage. The optimal interventions have not been evaluated by controlled trials and should be decided on a case-by-case basis with consideration of center expertise and family preferences.

Pathophysiology of Vascular Stenosis and Remodeling in Moyamoya Disease

Moyamoya disease (MMD) and moyamoya syndrome (MMS) are progressive vascular pathologies unique to the cerebrovasculature that are important causes of stroke in both children and adults. The natural history of MMD is characterized by primary progressive stenosis of the supraclinoid internal carotid artery, followed by the formation of fragile collateral vascular networks. In MMS, stenosis and collateralization occur in patients with an associated disease or condition. The pathological features of the stenosis associated with MMD include neointimal hyperplasia, disruption of the internal elastic lamina, and medial attenuation, which ultimately lead to progressive decreases in both luminal and external arterial diameter. Several molecular pathways have been implicated in the pathophysiology of stenosis in MMD with functions in cellular proliferation and migration, extracellular matrix remodeling, apoptosis, and vascular inflammation. Importantly, several of these molecular pathways overlap with those known to contribute to diseases of systemic arterial stenosis, such as atherosclerosis and fibromuscular dysplasia (FMD). Despite these possible shared mechanisms of stenosis, the contrast of MMD with other stenotic pathologies highlights the central questions underlying its pathogenesis. These questions include why the stenosis that is associated with MMD occurs in such a specific and limited anatomic location and what process initiates this stenosis. Further investigation of these questions is critical to developing an understanding of MMD that may lead to disease-modifying medical therapies. This review may be of interest to scientists, neurosurgeons, and neurologists involved in both moyamoya research and treatment and provides a review of pathophysiologic processes relevant to diseases of arterial stenosis on a broader scale.

Arteriopathy in pediatric stroke: an underestimated clinical entity

BACKGROUND

Pediatric arterial ischemic stroke (AIS), which was thought to be a rare disorder, is being increasingly recognized as an important cause of neurological morbidity, thanks to new advances in neuroimaging.

OBJECTIVE

The aim of this study was to review the main etiologies of stroke due to arteriopathy in children.

METHODS

Using a series of cases from our institution, we addressed its epidemiological aspects, physiopathology, imaging findings from CT, MR angiography, MR conventional sequences and MR DWI, and nuclear medicine findings.

RESULTS

Through discussion of the most recent classification for childhood AIS (Childhood AIS Standardized Classification and Diagnostic Evaluation, CASCADE), we propose a modified classification based on the anatomical site of disease, which includes vasculitis, varicella, arterial dissection, moyamoya, fibromuscular dysplasia, Takayasu's arteritis and genetic causes (such as ACTA-2 mutation, PHACE syndrome and ADA-2 deficiency). We have detailed each of these separately. Conclusions: Prompt recognition of AIS and thorough investigation for potential risk factors are crucial for a better outcome. In this scenario, neurovascular imaging plays an important role in diagnosing AIS and identifying children at high risk of recurrent stroke.

Hypoxic-ischemic injury causes functional and structural neurovascular degeneration in the juvenile mouse retina

Ischemic stroke is a major cause of long-term disabilities, including vision loss. Neuronal and blood vessel maturation can affect the susceptibility of and outcome after ischemic stroke. Although we recently reported that exposure of neonatal mice to hypoxia–ischemia (HI) severely compromises the integrity of the retinal neurovasculature, it is not known whether juvenile mice are similarly impacted. Here we examined the effect of HI injury in juvenile mice on retinal structure and function, in particular the susceptibility of retinal neurons and blood vessels to HI damage. Our studies demonstrated that the retina suffered from functional and structural injuries, including reduced b-wave, thinning of the inner retinal layers, macroglial remodeling, and deterioration of the vasculature. The degeneration of the retinal vasculature associated with HI resulted in a significant decrease in the numbers of pericytes and endothelial cells as well as an increase in capillary loss. Taken together, these findings suggest a need for juveniles suffering from ischemic stroke to be monitored for changes in retinal functional and structural integrity. Thus, there is an emergent need for developing therapeutic approaches to prevent and reverse retinal neurovascular dysfunction with exposure to ischemic stroke.

Hypertension and childhood stroke

Cerebrovascular disease (stroke) is one of the ten leading causes of death in children and adolescents. Multiple etiologies, from arteriopathies to prothrombic states, can cause stroke in youth. In adult stroke, hypertension has been shown to be the single most important modifiable risk factor. Although hypertension has not been strongly identified as a risk factor in childhood stroke to date, there is preliminary evidence that suggests that hypertension may also be associated with stroke in children. In this review, we summarize the literature that may link hypertension to stroke in the young. We have identified a series of barriers and limitations in the fields of pediatric hypertension and pediatric neurology that might explain why hypertension has been overlooked in childhood stroke. We suggest that hypertension may be a relevant risk factor that, alone or in combination with other multiple factors, contributes to the development of stroke in children. Currently, there are no consensus guidelines for the management of post-stroke hypertension in children. Thus, we recommend that blood pressure be assessed carefully in every child presenting with acute stroke in order to better understand the effects of hypertension in the development and the outcome of childhood stroke. We suggest a treatment algorithm to help practitioners manage hypertension after a stroke.

[Fibromuscular dysplasia and its neurological manifestations]

The authors present the current data on the classification, epidemiology, etiology, neurological manifestations, prognosis, diagnosis, and treatment of patients with fibromuscular dysplasia (FMD). The review is based on the selection of publications by searching PubMed for keywords from the first sources until March 2019. FMD is a segmental non-atherosclerotic and non-inflammatory disease of large- and medium-caliber arteries leading to their stenosis. The disease occurs mostly in women (90%), and manifests itself in the 5th decade of life. In the cerebrovascular form of FMD, the extracranial internal carotid artery and the vertebral artery are usually affected. Diagnosis is based on the identification of alternation of narrowing and dilation of arteries using angiography (the string of beads sign (multifocal form)). Neurological manifestations include headache, tinnitus, and ischemic stroke, usually due to the dissection or stenosis, rarely, intracerebral or subarachnoid hemorrhages. The prognosis in most cases is favorable, relapses of strokes are rare. Treatment includes antiplatelet agents, if they are ineffective to prevent recurrence of ischemic stroke, endovascular treatment is carried out. Approaches to the treatment of intracranial aneurysms do not differ from those in patients without FMD.

Prospective Screening of Extracranial Systemic Arteriopathy in Young Adults with Moyamoya Disease

Background

RNF213 is a major susceptibility gene for moyamoya disease (MMD), characterized by chronic progressive steno‐occlusion of the intracranial arteries. However, coincidental extracranial arteriopathy is sporadically described in a few cases and in children with MMD.

Methods and Results

This study prospectively enrolled 63 young adults (aged 20–49 years) without a known history of systemic vascular diseases who were confirmed to have definite (bilateral, n=54) or probable (unilateral, n=9) MMD, as per typical angiographic findings. Coronary and aorta computed tomography angiography was performed to characterize extracranial arteriopathy and investigate its correlation with clinical characteristics and MMD status, including the RNF213 p.Arg4810Lys variation (c.14429G>A, rs112735431). Altogether, 11 of 63 patients (17%) had significant (>50%) stenosis in the coronary (n=6), superior mesenteric (n=2), celiac (n=2), renal (n=1), and/or internal iliac artery (n=1). One patient showed both mesenteric and iliac artery stenosis. Patients with extracranial arteriopathy were more likely to have diabetes mellitus and posterior cerebral artery involvement. Moreover, a higher prevalence of extracranial arteriopathy was observed in the presence of the RNF213 p.Arg4810Lys variant (67% in homozygotes). After controlling for diabetes mellitus and posterior cerebral artery involvement, the p.Arg4810Lys variant was independently associated with extracranial arteriopathy (additive model; P=0.035; adjusted odds ratio, 4.57; 95% CI, 1.11–27.20).

Conclusions

Young adults with MMD may have concomitant extracranial arteriopathy in various locations. Patients with RNF213 variants, especially the p.Arg4810Lys homozygous variant, should be screened for systemic arteriopathy.

Fibromuscular Dysplasia and Its Neurologic Manifestations: A Systematic Review

Importance

Data on neurologic manifestations of fibromuscular dysplasia (FMD) are rare, and current knowledge remains limited.

Objectives

To present a comprehensive review of the epidemiologic characteristics, management, and prognosis of the neurologic manifestations associated with cerebrovascular FMD (ie, involving cervical or intracranial arteries) and to guide future research priorities.

Evidence Review

References were identified through searches of PubMed from inception to December 2017 using both the medical subject headings and text words. Additional sources were also identified by reviewing reference lists of relevant articles and through searches of the authors' personal files. Selected articles described at least 1 clinical or radiologic feature and/or outcome of cerebrovascular FMD. Isolated case reports could be included if they described interesting or noteworthy manifestations of FMD.

Findings

A total of 84 relevant references were identified. Diagnosis of cerebrovascular FMD is based on the appearance of alternating arterial dilatation and constriction ("string of beads") or of focal narrowing, with no sign of atherosclerotic or inflammatory lesions. Although the diagnosis is easily apparent on results of radiographic imaging, making a diagnosis can be challenging in children or individuals with atypical phenotypes, such as purely intracranial FMD and arterial diaphragm. Involvement of multiple arteries is common, and there is increased incidence of cervical artery dissection and intracranial aneurysms. A variant in the PHACTR1 gene has been associated with FMD as well as cervical artery dissection and migraine, although less than 5% of cases of FMD are familial. Headaches, mainly of the migraine type, are observed in up to 70% of patients with FMD. Cerebrovascular FMD is mostly asymptomatic, but the most frequent neurologic manifestations include transient ischemic attack and ischemic stroke, notably in the presence of associated cervical artery dissection. Other conditions associated with FMD include subarachnoid hemorrhage and, rarely, intracranial hemorrhage. Management relies on observational data and expert opinion. Antiplatelet therapy is considered reasonable to prevent thromboembolic complications. Endovascular therapy is typically restricted to cases with symptomatic stenosis despite optimal medical therapy or in those with rupture of an intracranial aneurysm.

Conclusions and Relevance

Longitudinal cohort studies of individuals of multiple ethnicities with biosampling are needed to better understand the risk factors, pathophysiological features, and outcomes of FMD. Patient advocacy groups could assist researchers in answering patient-centered questions regarding FMD.

Ischemic stroke in young adults

PURPOSE OF REVIEW

Although the clinical approach to the young adult stroke patient is similar to that of an older adult, several important differences exist. The purpose of this article is to concisely review the epidemiology, pathophysiology, risk factors, clinical manifestations, diagnostic methods and current treatment options for the young adult ischemic stroke patient.

RECENT FINDINGS

Evidence clearly indicates that the incidence ischemic stroke in young adults is on the rise. A variety of factors are implicated, including an increased burden of classic and emerging vascular risk factors, and improved stroke detection, among other causes. Improved awareness, prevention and successful treatment of the young adult stroke patient is of great importance, particularly given the major long-term socioeconomic impact strokes have on the patient, their family and society at large.

SUMMARY

In this review, we focus on the latest epidemiologic, diagnostic and treatment paradigms to improve physician awareness and optimize outcomes in young adult ischemic stroke patients. An overview of the clinical presentations of various stroke syndromes is described, emphasizing key causes physicians should consider, as well as providing recommendations regarding evaluation and treatment. Important causes including dissection and inflammatory and noninflammatory vasculopathies are emphasized. The diagnoses of cerebral venous thromboses, cardioembolic stroke and paradoxical emboli are also discussed. The effects of established and emerging risk factors on large and small vessel disease, as well as genetic contributions, are also highlighted.

Neuroimaging of Pediatric Arteriopathies

Pediatric arteriopathies are increasingly recognized in school-aged children with a variety of presenting symptoms ranging from headache, seizures, encephalopathy, and neuropsychiatric symptoms as well as focal neurologic deficits due to acute ischemic strokes. However, unlike the adult stroke population, there are differences in the clinical manifestations, the stroke mechanism, and risk factors in pediatric ischemic stroke. There has been increasing awareness and recognition of pediatric cerebral arteriopathies as a predominant stroke etiology. Prompt diagnosis of arteriopathies is essential to limit injury and prevent recurrent stroke. Based on predominant vessels involved and clinical symptoms, these arteriopathies can be broadly divided into two categories: large-medium size arteriopathies and small vessel arteriopathies. Each category can be further divided into inflammatory and noninflammatory according to their etiologies. The ability to distinguish between inflammatory and noninflammatory etiologies carries major prognostic implications for acute management and secondary stroke prevention as well as screening for systemic complications and counseling.

Pediatric Stroke Imaging

BACKGROUND

Pediatric stroke is a distinct clinical entity as compared with that in adults due to its unique and diverse set of etiologies. Furthermore, the role and application of diagnostic imaging has specific constraints and considerations. The intention of this article is to review these concepts in a thorough manner to offer a pediatric stroke imaging framework that providers can employ when taking care of these patients.

METHODS

A comprehensive primary and secondary literature review was performed with specific attention to the common causes of pediatric stroke, appropriate use of neuroimaging, specific imaging findings, and developing techniques which may improve our ability to accurately diagnose these patients.

RESULTS

Findings from this literature review were synthesized and summarized in order to thoroughly review the aforementioned concepts and outline the current consensus-based approach to diagnostic imaging in pediatric stroke. Furthermore, imaging findings drawn from patients seen in our institution are demonstrated to familiarize readers with pediatric stroke neuroimaging.

CONCLUSIONS

The challenges posed by pediatric stroke can be mitigated, in part, by the thoughtful application of diagnostic imaging, with the ultimate hope of improving outcomes for these vulnerable patients.

Imaging studies in pediatric fibromuscular dysplasia (FMD): a single-center experience

BACKGROUND

Fibromuscular dysplasia (FMD) is a non-inflammatory vascular disease that in children unlike in adults shows no sex predilection. FMD is often underdiagnosed, and its pathophysiology is unclear. Delayed diagnosis may lead to refractory hypertension and decreases the chance of successful treatment. Doppler ultrasound (US), magnetic resonance angiography (MRA), computed tomography angiography (CTA), and catheter-based angiography (angiography) are currently used to help make a clinicoradiological diagnosis of FMD. The main aim of the study was to compare the efficacy of imaging modalities which can allow for earlier and improved detection. Furthermore, an anatomical mapping of the location of lesions can help determine the best treatment modalities.

METHODS

All patients with non-syndromic non-inflammatory renovascular hypertension were recruited from the Nephrology Department at the Children's Hospital of Philadelphia (CHOP) and enrolled in the U.S. FMD Registry maintained at the University of Michigan. Clinical presentation and imaging findings on US, CT, and MRI of children diagnosed with FMD were evaluated.

RESULTS

Mean age at diagnosis was 7 ± 4.9 years (4 months-17 years). Family history of hypertension (HTN) (52%), FMD (8.7%), Caucasian (60%), headache (48%), and HTN (80%) were the most prevalent symptom and sign at presentation. Bruits were 100% specific for renal artery stenosis (RAS) diagnosis but were heard in the minority of patients (3 patients, 12%). FMD was mainly unifocal within a single site (68%) or multiple sites (28%) and involved the main or first order renal branch in about 68% of children. Isolated distal lesions beyond the second order branches were found in about 25% of children. US imaging was significantly less sensitive than angiography (28%, p = 0.003). MRA had a better sensitivity (62.5%, p = 0.3) than US. Overall, CTA had the best sensitivity (84.2%, p = 0.4) compared to angiography; however, only angiography showed distal vessel disease.

CONCLUSIONS

Limitations of the study include the sample size and biases-only patients diagnosed with FMD were included in this study and most patients were referred to a pediatric nephrologist for unexplained hypertension. Angiography should be performed as part of the initial work-up of any child suspected of having renovascular FMD, regardless of the findings seen on US, MRA, or CTA.

Genomics of Fibromuscular Dysplasia

Fibromuscular Dysplasia (FMD) is &ldquo;an idiopathic, segmental, non-atherosclerotic and non-inflammatory disease of the musculature of arterial walls, leading to stenosis of small and medium-sized arteries&rdquo; (Persu, et al; 2014). FMD can lead to hypertension, arterial dissections, subarachnoid haemorrhage, stroke or mesenteric ischemia. The pathophysiology of the disease remains elusive. While familial cases are rare (<5%) in contemporary FMD registries, there is evidence in favour of the existence of multiple genetic factors involved in this vascular disease. Recent collaborative efforts allowed the identification of a first genetic locus associated with FMD. This intronic variant located in the phosphatase and actin regulator 1 gene (PHACTR1) may influence the transcription activity of the endothelin-1 gene (EDN1) located nearby on chromosome 6. Interestingly, the PHACTR1 locus has also been involved in vascular hypertrophy in normal subjects, carotid dissection, migraine and coronary artery disease. National and international registries of FMD patients, with deep and harmonised phenotypic and genetic characterisation, are expected to be instrumental to improve our understanding of the genetic basis and pathophysiology of this intriguing vascular disease.

Clinical and Imaging Characteristics of Arteriopathy Subtypes in Children with Arterial Ischemic Stroke: Results of the VIPS Study

BACKGROUND AND PURPOSE

Childhood arteriopathies are rare but heterogenous, and difficult to diagnose and classify, especially by nonexperts. We quantified clinical and imaging characteristics associated with childhood arteriopathy subtypes to facilitate their diagnosis and classification in research and clinical settings.

MATERIALS AND METHODS

The Vascular Effects of Infection in Pediatric Stroke (VIPS) study prospectively enrolled 355 children with arterial ischemic stroke (2010-2014). A central team of experts reviewed all data to diagnose childhood arteriopathy and classify subtypes, including arterial dissection and focal cerebral arteriopathy-inflammatory type, which includes transient cerebral arteriopathy, Moyamoya disease, and diffuse/multifocal vasculitis. Only children whose stroke etiology could be conclusively diagnosed were included in these analyses. We constructed logistic regression models to identify characteristics associated with each arteriopathy subtype.

RESULTS

Among 127 children with definite arteriopathy, the arteriopathy subtype could not be classified in 18 (14%). Moyamoya disease (n = 34) occurred mostly in children younger than 8 years of age; focal cerebral arteriopathy-inflammatory type (n = 25), in children 8-15 years of age; and dissection (n = 26), at all ages. Vertigo at stroke presentation was common in dissection. Dissection affected the cervical arteries, while Moyamoya disease involved the supraclinoid internal carotid arteries. A banded appearance of the M1 segment of the middle cerebral artery was pathognomonic of focal cerebral arteriopathy-inflammatory type but was present in <25% of patients with focal cerebral arteriopathy-inflammatory type; a small lenticulostriate distribution infarct was a more common predictor of focal cerebral arteriopathy-inflammatory type, present in 76%. It remained difficult to distinguish focal cerebral arteriopathy-inflammatory type from intracranial dissection of the anterior circulation. We observed only secondary forms of diffuse/multifocal vasculitis, mostly due to meningitis.

CONCLUSIONS

Childhood arteriopathy subtypes have some typical features that aid diagnosis. Better imaging methods, including vessel wall imaging, are needed for improved classification of focal cerebral arteriopathy of childhood.

A Diagnostic Approach to Stroke in Young Adults

OPINION STATEMENT

Optimal diagnosis and management of stroke in young adults benefit from a multidisciplinary team, including a vascular neurology specialist. In addition to the "standard" vascular risk factors including smoking, hypertension, diabetes, and hyperlipidemia, one needs to consider alternative etiologies including substance abuse, carotid/vertebral artery dissections, and rare genetic conditions among others. Once a young patient is determined to have had a stroke, the next question a clinician should ask is why did this patient have a stroke? A "heart to head" diagnostic approach is recommended. A thorough history is performed, including a detailed family history with specific annotations on each family member. A thorough physical examination is necessary including a careful evaluation of the patient's general appearance, noting any joint laxity, and/or abnormalities of the skin, eyes, and heart. Findings across multiple organ systems in the patient and/or their family may indicate a genetic etiology. After an initial head CT rules out hemorrhagic stroke, additional testing should include a brain MRI, neck and cerebral vascular imaging (e.g., CTA for head and neck), transthoracic echocardiogram with a bubble study, telemetry monitoring, basic risk factor blood work (e.g., lipid panel, hemoglobin A1c, TSH, ESR, CRP, RPR, HIV, and toxicology screen), and, when appropriate, sickle screen and pregnancy test. There should be a low threshold to obtain blood cultures or a lumbar puncture. The acute treatment of ischemic stroke in young adult patients does not differ from treatment of older adults, using intravenous alteplase within 4.5 h, assuming no contraindications. In suspected proximal large artery occlusive disease, interventional clot extraction procedures should be employed in patients deemed eligible. Long-term secondary prevention strategies aimed to reduce recurrent stroke risk by targeting and modifying vascular risk factors should be instituted. The mainstay of preventative therapy is aspirin for most etiologies; however, for atrial fibrillation, anticoagulation is recommended. Statin therapy is another pharmacologic intervention recommended in most stroke patients. Other measures employed are blood pressure reduction, smoking cessation, optimal glucose control in diabetic patients, the initiation of a healthy diet and regular exercise, and lastly, substance abuse counseling in appropriate patients.

Rapid contralateral progression of focal cerebral arteriopathy distinguished from RNF213-related moyamoya disease and fibromuscular dysplasia

BACKGROUND

Focal cerebral arteriopathy includes unifocal or multifocal lesions that are unilateral or bilateral. Large- and/or medium-sized vessels are involved and can be visualized on angiography.

CASE REPORT

We report a case of cerebral infarction in a 9-year-old Japanese female who presented with a transient ischemic attack. Steno-occlusion involving the distal part of the internal carotid artery, proximal middle cerebral artery, and anterior cerebral artery was observed. Digital subtraction angiography demonstrated a beaded appearance in the cervical portion of the diseased internal carotid artery. Revascularization surgery was performed 45 days after the onset. A new infarction appeared on the other side of the anterior cerebral artery territory 7 months after the first onset. Antiplatelets and vasodilators were administered, and no progression was observed during 18 months of follow-up. Genetic analysis did not show ring finger protein 213 (RNF213)-related moyamoya disease, and pathological examination revealed no characteristics of fibromuscular dysplasia.

CONCLUSION

The radiological and genetic features coincided with focal cerebral arteriopathy, which is a distinct entity from fibromuscular dysplasia and RNF213-related moyamoya disease.

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.

Pediatric arterial ischemic stroke: Epidemiology, risk factors, and management

Pediatric arterial ischemic stroke (AIS) is an uncommon but important cause of neurologic morbidity in neonates and children, with consequences including hemiparesis, intellectual disabilities, and epilepsy. The causes of pediatric AIS are unique to those typically associated with stroke in adults. Familiarity with the risk factors for AIS in children will help with efficient diagnosis, which is unfortunately frequently delayed. Here we review the epidemiology and risk factors for AIS in neonates and children. We also outline consensus-based practices in the evaluation and management of pediatric AIS. Finally we discuss the outcomes observed in this population. While much has been learned in recent decades, many uncertainties sill persist in regard to pediatric AIS. The ongoing development of specialized centers and investigators dedicated to pediatric stroke will continue to answer such questions and improve our ability to effectively care for these patients.

Stroke and Hypertension in Children and Adolescents

Hypertension is the single most important modifiable risk factor for adult stroke. Stroke mortality has significantly decreased over the last 5 decades; this decline has been mainly associated to improved blood pressure control. Though much less prevalent than in adults, stroke is an increasingly recognized cause of morbidity and mortality in children. Although hypertension has not been strongly identified as a risk factor in childhood stroke yet, there is preliminary evidence that suggests that elevated blood pressure may be associated with stroke in children. This review summarizes the literature that may link elevated blood pressure to the development of childhood ischemic and hemorrhagic stroke. The authors suggest that elevated blood pressure may be a significant risk factor that, alone or in combination with other multiple risk factors, leads to the development of stroke in childhood. It is therefore recommend that blood pressure be measured and assessed carefully in every child presenting with acute stroke.

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.

Differences between the pediatric and adult presentation of fibromuscular dysplasia: results from the US Registry

BACKGROUND

Fibromuscular dysplasia (FMD) is a non-inflammatory arteriopathy that causes significant morbidity in children.

METHODS

The clinical features, presenting symptoms, and vascular beds involved are reviewed in the first 33 patients aged <18 years who are enrolled in the United States Registry for FMD from five registry sites and compared with 999 adult patients from 12 registry sites.

RESULTS

Mean age at diagnosis was 8.4 ± 4.8 years (16 days to 17 years). Compared with adults, pediatric FMD occurs in more males (42.4 vs 6 %, p < 0.001). Children with FMD have a stronger previous history of hypertension (93.9 vs 69.9 %, p = 0.002). Hypertension (100 %), headache (55 %), and abdominal bruits (10.7 %) were the most common presenting signs and symptoms. FMD affects renal vasculature in almost all children (97 vs 69.7 %, p = 0.003). The extra-cranial carotid vessels are less commonly involved in children (23.1 vs 73.3 %, p < 0.001). The mesenteric arteries (38.9 vs 16.2 %, p = 0.02) and aorta (26.3 vs 2.4 %, p < 0.001) are more commonly involved in children.

CONCLUSIONS

In the United States Registry for FMD, pediatric FMD affects children from infancy throughout childhood. All children presented with hypertension and many presented with headache and abdominal bruits. In children, FMD most commonly affects the renal vasculature, but also frequently involves the mesenteric arteries and abdominal aorta; the carotid vessels are less frequently involved.

Arterial Tortuosity: An Imaging Biomarker of Childhood Stroke Pathogenesis?

BACKGROUND AND PURPOSE

Arteriopathy is the leading cause of childhood arterial ischemic stroke. Mechanisms are poorly understood but may include inherent abnormalities of arterial structure. Extracranial dissection is associated with connective tissue disorders in adult stroke. Focal cerebral arteriopathy is a common syndrome where pathophysiology is unknown but may include intracranial dissection or transient cerebral arteriopathy. We aimed to quantify cerebral arterial tortuosity in childhood arterial ischemic stroke, hypothesizing increased tortuosity in dissection.

METHODS

Children (1 month to 18 years) with arterial ischemic stroke were recruited within the Vascular Effects of Infection in Pediatric Stroke (VIPS) study with controls from the Calgary Pediatric Stroke Program. Objective, multi-investigator review defined diagnostic categories. A validated imaging software method calculated the mean arterial tortuosity of the major cerebral arteries using 3-dimensional time-of-flight magnetic resonance angiographic source images. Tortuosity of unaffected vessels was compared between children with dissection, transient cerebral arteriopathy, meningitis, moyamoya, cardioembolic strokes, and controls (ANOVA and post hoc Tukey). Trauma-related versus spontaneous dissection was compared (Student t test).

RESULTS

One hundred fifteen children were studied (median, 6.8 years; 43% women). Age and sex were similar across groups. Tortuosity means and variances were consistent with validation studies. Tortuosity in controls (1.346±0.074; n=15) was comparable with moyamoya (1.324±0.038; n=15; P=0.998), meningitis (1.348±0.052; n=11; P=0.989), and cardioembolic (1.379±0.056; n=27; P=0.190) cases. Tortuosity was higher in both extracranial dissection (1.404±0.084; n=22; P=0.021) and transient cerebral arteriopathy (1.390±0.040; n=27; P=0.001) children. Tortuosity was not different between traumatic versus spontaneous dissections (P=0.70).

CONCLUSIONS

In children with dissection and transient cerebral arteriopathy, cerebral arteries demonstrate increased tortuosity. Quantified arterial tortuosity may represent a clinically relevant imaging biomarker of vascular biology in pediatric stroke.

Central nervous system vasculitis in adults and children

Primary angiitis of the central nervous system (PACNS) is an inflammatory brain disease targeting the cerebral blood vessels, leading to a wide spectrum of signs and symptoms, including neurologic deficits, cognitive dysfunction, and psychiatric symptoms. The inflammation could be reversible if diagnosed and treated early. The diagnosis requires the careful consideration and rapid evaluation of systemic underlying conditions and disease mimics. The differential diagnosis is distinctly different for angiography-positive and -negative PACNS subtypes and differs depending on age, so there is childhood PACNS or adult PACNS. Distinct disease subtypes have been described, with characteristic disease course, neuroimaging findings, and histopathologic features. Novel and traditional biomarkers, including von Willebrand factor antigen and cytokine levels, can help diagnose, and define subtype and disease activity. Treatment of PACNS should be tailored to the disease subtypes and clinical symptoms. Beyond immunosuppression it should include medications to control symptoms in order to support and enhance the child's or adult's ability to actively participate in rehabilitation. The mortality of PACNS has decreased; studies determining the morbidity and its determinants are urgently needed.

Focal Cerebral Arteriopathy: The Face With Many Names

OBJECTIVE

Focal cerebral arteriopathy is a term used to describe unilateral intracranial arteriopathy involving the distal internal carotid artery and proximal segments of the middle and anterior cerebral artery. We describe the disease course of 10 pediatric arterial ischemic stroke patients with focal cerebral arteriopathy from a single quaternary-care center.

METHODS

We retrospectively reviewed pediatric stroke patients with focal cerebral arteriopathy without lenticulostriate collaterals treated at our institution between 2005 and 2014. Angiography was reviewed by a child neurologist and a pediatric neuroradiologist, and chart reviews were performed.

RESULTS

Ten individuals with focal cerebral arteriopathy were identified. At the time of stroke presentation, four patients were diagnosed with arterial dissection, two with moyamoya disease, one with embolic occlusion, one with hemorrhagic stroke, and two with arterial dissection or vasculitis. At last follow-up, six patients had a change in diagnosis: four were diagnosed with transient cerebral arteriopathy, two with arterial dissection, and four with moyamoya disease. Four children experienced stroke recurrence. All were administered aspirin, one was administered heparin, two were administered intravenous tissue plasminogen activator, and five underwent surgical revascularization.

CONCLUSIONS

Among pediatric stroke patients with a similar angiographic appearance, there is variable concordance between diagnosis, prognosis and treatment choice. Improved consensus-based diagnostic criteria and further research is needed to identify disease biomarkers and predictors of arterial progression.

Arteriopathy diagnosis in childhood arterial ischemic stroke: results of the vascular effects of infection in pediatric stroke study

BACKGROUND AND PURPOSE

Although arteriopathies are the most common cause of childhood arterial ischemic stroke, and the strongest predictor of recurrent stroke, they are difficult to diagnose. We studied the role of clinical data and follow-up imaging in diagnosing cerebral and cervical arteriopathy in children with arterial ischemic stroke.

METHODS

Vascular effects of infection in pediatric stroke, an international prospective study, enrolled 355 cases of arterial ischemic stroke (age, 29 days to 18 years) at 39 centers. A neuroradiologist and stroke neurologist independently reviewed vascular imaging of the brain (mandatory for inclusion) and neck to establish a diagnosis of arteriopathy (definite, possible, or absent) in 3 steps: (1) baseline imaging alone; (2) plus clinical data; (3) plus follow-up imaging. A 4-person committee, including a second neuroradiologist and stroke neurologist, adjudicated disagreements. Using the final diagnosis as the gold standard, we calculated the sensitivity and specificity of each step.

RESULTS

Cases were aged median 7.6 years (interquartile range, 2.8-14 years); 56% boys. The majority (52%) was previously healthy; 41% had follow-up vascular imaging. Only 56 (16%) required adjudication. The gold standard diagnosis was definite arteriopathy in 127 (36%), possible in 34 (9.6%), and absent in 194 (55%). Sensitivity was 79% at step 1, 90% at step 2, and 94% at step 3; specificity was high throughout (99%, 100%, and 100%), as was agreement between reviewers (κ=0.77, 0.81, and 0.78).

CONCLUSIONS

Clinical data and follow-up imaging help, yet uncertainty in the diagnosis of childhood arteriopathy remains. This presents a challenge to better understanding the mechanisms underlying these arteriopathies and designing strategies for prevention of childhood arterial ischemic stroke.

Etiology and treatment of arterial ischemic stroke in children and young adults

OPINION STATEMENT

Stroke is the second leading cause of death worldwide (Go et al. Circulation 129:e28-292, 2014) and is a major cause of morbidity and mortality. Compared with older adults, arterial ischemic stroke (AIS) is relatively uncommon in children and young adults, comprising 5-10 % of all stroke (Biller Nat Rev Cardiol 6:395-97, 2009), but is associated with significant cost. In contrast to the declining overall incidence of stroke, some early studies suggest that the rate of stroke hospitalizations in children and young adults is rising (George et al. Ann Neurol 70:713-21, 2011; Kissela et al. Stroke 41:e224, 2010; Nguyen-Huynh et al. Stroke 43, 2012), emphasizing the importance of understanding the similarities and differences in etiology and treatment of AIS across the age spectrum. Among the most common causes of AIS in children are cardioembolism (often related to congenital heart disease), cervicocephalic arterial dissections, focal arteriopathy of childhood and several genetic and metabolic disorders, such as sickle cell disease (SCD). AIS in young adults is less well understood, but likely overlaps in etiology with both children and older adults. Young adults with AIS often have classic atherosclerotic risk factors similar to older adults, but are also more likely to have thrombophilias, cervicocephalic arterial dissections and cardioembolism, similar to children with AIS. Since little evidence exists regarding both acute treatment and secondary prevention after AIS in children and young adults, standard treatment practices are mainly extrapolated from research done in older adults. In most cases we recommend treating young adults per the guidelines published by the American Heart Association for adults with stroke (Jauch et al. Stroke 44:870-947, 2013; Kernan et al. Stroke 45:2160-2236, 2014) and children per the equivalent guidelines regarding pediatric stroke (Roach et al. Stroke 39:2644-91, 2008). It is also important in children and young adults to consider less common structural, metabolic and genetic risk factors for stroke, which may require more specific treatment. Other standard risk factors for stroke, including hypertension, hyperlipidemia and diabetes mellitus should also be addressed, but are less likely in children and young adults. Given the lack of data and possibility of rare underlying etiologies such as Antiphospholipid Antibody Syndrome or Ehlers-Danlos syndrome, we recommend including multiple specialists in the care of these patients, such as hematologists and vascular neurologists.

[Childhood cerebral vasculitis]

Central nervous system vasculitides are defined as the invasion of the vascular wall by blood-borne inflammatory cells. In childhood, they may be classified according to their trigger event (infectious vs. non-infectious), their temporal course (time-limited vs. chronic), and the size of the affected vessel. Diseases apparently confined to the central nervous system are also distinguished from secondary forms, associated with infection or rheumatic or systemic inflammatory disorders. Large-vessel vasculitis, the most frequent form, causes stroke and presents with acute focal deficits. MR, or more seldom contrast angiography is required for the positive diagnosis, while the child's medical history conveys the etiological diagnosis. The clinical manifestations of small-vessel vasculitis include headaches, seizures, focal deficits, cognitive decline, and behavior changes that can occur insidiously over a few weeks or a few months. The diagnosis is based on the associated clinical and biological symptoms in secondary forms and on cerebromeningeal biopsy in primary forms. Secondary forms of vasculitides are treated according to the etiology. The injury of large basal arteries is often observed after infection, especially varicella, and is also called transient focal cerebral arteriopathy (TCA) or post-varicella arteriopathy (PVA). This focal, monophasic, and time-limited entity is highly specific of childhood. There are no arguments in the current literature supporting the hypothesis that an aggressive immunomodulatory treatment would be more effective, in terms of recurrence rate or functional outcome, than aspirin alone. In contrast, the diffuse, prolonged, and aggressive course of the rare primary vasculitis of the central nervous system requires a prolonged immunosuppressive treatment. The management of associated symptoms, treatment-related adverse effects, and sequelae is based on a multidisciplinary approach.

Central retinal artery occlusion in association with fibromuscular dysplasia

A 14 year-old female, whose chief complaint was severe vision loss in the right eye for 2 days, presented to the Clinic of Ophthalmology of Fatih Sultan Mehmet Education and Research Hospital. The patient had been attending follow-up visits for 4 years, following a diagnosis of fibromuscular dysplasia by the Clinic of Pediatrics. The patient underwent a complete ophthalmo-logic, angiographic, hematologic, and systemic evaluation. Fundus fluorescein angiography was performed immediately, because of the cherry-red spot sign in the macula of the right eye. Fundus fluorescein angiography revealed evidence of marked stasis of the retinal arterial circulation in the right eye. Best corrected visual acuity was 20/400 in the right eye and 20/20 in the left eye.