Fatal varicella-zoster virus antigen-positive giant cell arteritis of the central nervous system

Inflammatory Type Focal Cerebral Arteriopathy of the Posterior Circulation in Children: A Comparative Cohort Study

BACKGROUND

Inflammatory type focal cerebral arteriopathy (FCA-i) in the anterior circulation (AC) is well characterized, and the focal cerebral arteriopathy severity score (FCASS) reflects the severity of the disease. We identified cases of FCA-i in the posterior circulation (PC) and adapted the FCASS to describe these cases.

METHODS

In this comparative cohort study, patients from the Swiss NeuroPaediatric Stroke Registry with ischemic stroke due to FCA-i between January 2000 and December 2018 were analyzed. A comparison between PC and AC cases regarding pediatric National Institutes of Health Stroke Scale score and pediatric stroke outcome measure and FCASS was performed. We estimated infarct size by the modified pediatric Alberta Stroke Program Early Computed Tomography Score in children with AC stroke and the adapted Bernese posterior diffusion-weighted imaging score in the PC.

RESULTS

Thirty-five children with a median age of 6.3 (interquartile range, 2.7-8.2 [95% CI, 0.9-15.6]; 20 male; 57.1%) years with FCA-i were identified. The total incidence rate was 0.15/100 000/year (95% CI, 0.11-0.21). Six had PC-FCA-i. Time to final FCASS was longer in the PC compared with AC; the evolution of FCASS did not differ. Initial pediatric National Institutes of Health Stroke Scale score was higher in children with FCA-i in the PC with a median of 10.0 (interquartile range, 5.75-21.0) compared with 4.5 (interquartile range, 2.0-8.0) in those with AC-FCA-i. Different from the anterior cases, PC infarct volume did not correlate with higher discharge, maximum, or final FCASS scores (Pearson correlation coefficient [r], 0.25, 0.35, and 0.54).

CONCLUSIONS

FCA-i also affects the PC. These cases should be included in future investigations into FCA-i. Although it did not correlate with clinical outcomes in our cohort, the modified FCASS may well serve as a marker for the evolution of the arteriopathy in posterior FCA-i.

The Role of Infection and Inflammation in the Pathogenesis of Pediatric Arterial Ischemic Stroke

Infections play an important role in the pathogenesis of acute ischemic stroke (AIS) in neonates and children. In neonates, chorioamnionitis or intrauterine inflammation has been implicated as a common risk factor for AIS. In infants and children, recent investigations demonstrated that even minor childhood infections are associated with subsequent increased risk for AIS. Post-infectious inflammatory mechanisms following infections with herpesviruses may lead to focal cerebral arteriopathy (FCA), one of the most common causes of AIS in a previously healthy child. Other agents such as parvovirus B19, dengue virus, and SARS-CoV-2 have recently been implicated as other potential triggers. Infections are compelling treatable stroke risk factors, with available therapies for both pathogens and downstream inflammatory effects. However, infections are common in childhood, while stroke is uncommon. The ongoing VIPS II (Vascular effects of Infection in Pediatric Stroke) study aims to identify the array of pathogens that may lead to childhood AIS and whether either unusual strains or unusual combinations of pathogens explain this paradox. Immune modulation with corticosteroids for FCA is another active area of research, with European and U.S. trials launching soon. The results of these new pediatric stroke studies combined with findings emerging from the larger field of immune-mediated post-infectious diseases will likely lead to new approaches to the prevention and treatment of pediatric stroke. This review highlights recent developments from both clinical and animal model research enhancing our understanding of this relationship between infection, inflammation, and stroke in neonates and children.

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.

Common Features Between Stroke Following Varicella in Children and Stroke Following Herpes Zoster in Adults : Varicella-Zoster Virus in Trigeminal Ganglion

The cerebral arteries are innervated by afferent fibers from the trigeminal ganglia. Varicella-zoster virus (VZV) frequently resides in the trigeminal ganglion. Reports of arterial ischemic stroke due to VZV cerebral vasculopathy in adults after herpes zoster have been described for decades. Reports of arterial ischemic stroke due to post-varicella cerebral arteriopathy in children have also been described for decades. One rationale for this review has been post-licensure studies that have shown an apparent protective effect from stroke in both adults who have received live zoster vaccine and children who have received live varicella vaccine. In this review, we define common features between stroke following varicella in children and stroke following herpes zoster in adults. The trigeminal ganglion and to a lesser extent the superior cervical ganglion are central to the stroke pathogenesis pathway because afferent fibers from these two ganglia provide the circuitry by which the virus can travel to the anterior and posterior circulations of the brain. Based on studies in pseudorabies virus (PRV) models, it is likely that VZV is carried to the cerebral arteries on a kinesin motor via gE, gI and the homolog of PRV US9. The gE product is an essential VZV protein.

Fifteen-minute consultation: A structured approach to the management of stroke in a child

Childhood stroke is a rare but important diagnosis. Even though most children with stroke are ultimately cared for by specialist multidisciplinary paediatric neurology teams, their initial presentation will have been to a general paediatric admissions team. Assessing and managing children who present with stroke in the general paediatric setting can be challenging due to wide variation in its clinical features and underlying aetiologies. Despite the clarity provided by the Royal College of Paediatrics and Child Health recommendations which were published in 2017, many paediatricians still feel ill-prepared when assessing these high-risk patients. This article aims to provide an informative and structured approach to the assessment and management of children with stroke.

Recent developments and new frontiers in childhood arterial ischemic stroke

This review will discuss important developments in childhood arterial ischemic stroke over the past decade, focusing on improved understanding of the causes, consequences, and targets for intervention. Risk factors for childhood arterial ischemic stroke are different to adults. Infections, particularly herpes group viruses, are important precipitants for stroke. Non-atherosclerotic arteriopathies are the most common cause of childhood arterial ischemic stroke and an important predictor of recurrent events. Recent advances include the identification of serum biomarkers for inflammation and endothelial injury, and imaging biomarkers to monitor for vascular progression. Multicenter trials of immunotherapies in focal cerebral arteriopathies are currently in development. Recognition of clinical and radiological phenotypic patterns has facilitated the discovery of multisystem disorders associated with arterial ischemic stroke including ACTA2 arteriopathy and adenosine deaminase 2 deficiency. Identification of these Mendelian disorders provide insights into genetic mechanisms of disease and have implications for medical and surgical management. In contrast to adults, there are long diagnostic delays in childhood arterial ischemic stroke. Refinement of pediatric Code Stroke protocols and clinical decision support tools are essential to improve diagnostic certainty and improve access to reperfusion therapies. Children do not recover better than adults following arterial ischemic stroke, with more than half of survivors having long-term impairments. The physical, cognitive, and behavioral consequences of childhood arterial ischemic stroke are increasingly reported but further research is required to understand their impact on participation, quality of life, psychosocial, and family functioning. Longitudinal studies and the use of advanced imaging techniques, to understand neurobiological correlates of functional reorganization, are essential to developing targeted intervention strategies to facilitate recovery.

Diagnosis and Treatment of Primary Central Nervous System Angiitis

PURPOSE OF REVIEW

Primary central nervous system angiitis (PCNSA) is a rare disease. Varying clinical pictures coupled with lack of sensitive and specific diagnostic tests lead to challenges in management of these patients. This unfortunately may lead to both under- or over-diagnosis and unnecessary treatment. It is important to recognize the different conditions that may mimic the clinical and radiologic presentation. We present a contemporary literature review that should update physicians who encounter this patient population.

RECENT FINDINGS

Recent additions to the literature in form of case reports and single-center series show that digital subtraction angiography was the most widely used test to diagnose PCNSA. It is also important to note that brain biopsy is still considered "gold standard" and should be pursued as it not only has information that establishes the diagnosis but also may help in ruling out the diagnosis from mimics. In around 39% of suspected cases, an alternate diagnosis was eventually confirmed highlighting the importance of a comprehensive work-up. For treatment, almost all the literature supports the use of glucocorticoids as the initial treatment and if the patient has a relapse or develops steroid toxicity then the second most commonly used agent was cyclophosphamide. There are increasing reports of benefits with other agents such as methotrexate, azathioprine, mycophenolate, infliximab, and etanercept. The diagnosis and management of PCNSA continues to be a challenge. Formation of prospective patient registries with continued immunologic research for novel targets and immunomodulatory modalities may hold promise for future care of these patients.

[Stroke in children and adolescents]

The occurrence of a stroke in children and adolescents constitutes a rare, critical event that is associated with substantial morbidity and mortality. In addition to the individual suffering for the young patient and the medical burden for the affected family, a stroke is also associated with high follow-up costs for the health system because of the necessary long-term rehabilitative treatment. Establishing an early and prompt diagnosis is of great therapeutic importance. Because of the rarity of the illness and the plethora of clinical manifestations, diagnosis is often delayed. The most frequent clinical presentation is an acute focal-neurological deficit, usually in the form of hemiparesis, but headache, seizures or alteration of consciousness may also be seen. Nowadays, the prompt performance of diffusion-weighted, blood-sensitive magnetic resonance imaging (MRI) constitutes the gold standard. The most relevant risk factors for the occurrence of a stroke in this age cohort are vasculopathies, infections, pathological cardiac conditions or coagulopathies. Recurrence of stroke is dependent on the underlying risk factors. In a substantial percentage of patients, residual neurological deficits are seen.Owing to a lack of randomized controlled trials in children and adolescents with stroke, the optimal treatment approach is still under debate. In addition to anti-platelet medication and heparinization, systematic intravenous thrombolysis and endovascular thrombectomy are other potentially effective treatment options. The long-term prognosis in children is dependent on establishing a correct, early diagnosis.

Neuroinflammation in Ischemic Pediatric Stroke

Over the last decades, the importance of inflammatory processes in pediatric stroke have become increasingly evident. Ischemia launches a cascade of events: activation and inhibition of inflammation by a large network of cytokines, adhesion and small molecules, protease, and chemokines. There are major differences in the neonatal brain compared to adult brain, but developmental trajectories of the process during childhood are not yet well known. In neonatal stroke ischemia is the leading pathophysiology, but infectious and inflammatory processes have a significant input into the course and degree of tissue damage. In childhood, beside inflammation lanced by ischemia itself, the event of ischemia might be provoked by an underlying inflammatory pathophysiology: transient focal arteriopathy, dissection, sickle cell anemia, Moyamoya and more generalized in meningitides, generalized vasculitis or genetic arteriopathies (as in ADA2). Focal inflammatory reactions tend to be located in the distal part of the carotid artery or the proximal medial arteries, but generalized processes rather tend to affect the small arteries.

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.

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.

Nonprogressive Unilateral Intracranial Arteriopathy in Children with Arterial Ischemic Stroke

The nonprogressive unilateral intracranial arteriopathy known as transient (focal) cerebral arteriopathy is not a well-recognized arteriopathy among practitioners of Korea and Japan, although it cannot be easily differentiated from early moyamoya disease. This review summarizes the nomenclature, pathophysiology, diagnostic evaluation, clinico-radiological features, and management of nonprogressive (reversible or stable) unilateral arteriopathy based on the relevant literature and our own experiences. Nonprogressive unilateral arteriopathy should be strongly suspected in children presenting with basal ganglia infarction and arterial beading. The early identification of patients likely to have nonprogressive or progressive arteriopathy would ensure proper management and guide further research for secondary stroke prevention.

[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.

Arterial ischemic stroke in children: risk factors and etiologies

Stroke is increasingly recognized as a significant cause of morbidity and mortality in children, and as a financial burden for families and society. Recent studies have identified and confirmed presumptive risk factors, and have identified novel associations with childhood arterial ischemic stroke. A better understanding of risk factors for stroke in children, which differ from the atherosclerotic risk factors in adults, is the first step needed to improve strategies for stroke prevention and intervention, and ultimately minimize the physical, mental, and financial burden of arterial ischemic stroke. Here, we discuss recent advances in research for selected childhood stroke risk factors, highlighting the progress made in our understanding of etiologic mechanisms and pathophysiology, and address the future directions for acute and long-term treatment strategies for pediatric stroke.

Pathogenesis and current approaches to control of varicella-zoster virus infections

Varicella-zoster virus (VZV) was once thought to be a fairly innocuous pathogen. That view is no longer tenable. The morbidity and mortality due to the primary and secondary diseases that VZV causes, varicella and herpes zoster (HZ), are significant. Fortunately, modern advances, including an available vaccine to prevent varicella, a therapeutic vaccine to diminish the incidence and ameliorate sequelae of HZ, effective antiviral drugs, a better understanding of VZV pathogenesis, and advances in diagnostic virology have made it possible to control VZV in the United States. Occult forms of VZV-induced disease have been recognized, including zoster sine herpete and enteric zoster, which have expanded the field. Future progress should include development of more effective vaccines to prevent HZ and a more complete understanding of the consequences of VZV latency in the enteric nervous system.

[Current management of post-varicella stroke in children: a literature review]

Among infectious factors, varicella-zoster virus (VZV) is a leading cause of central nervous system vasculopathy and stroke in childhood. Not only have viral markers been detected in the cerebrospinal fluid of affected patients, but also direct evidence of viral particles in the wall of cerebral arteries has been demonstrated in rare pathological specimens. This certainly reflects a localized infectious process likely associated with variable indirect inflammatory responses. Yet the usefulness in this setting of a lumbar puncture as well as of subsequent targeted antiviral and/or anti-inflammatory therapies is uncertain. Indeed, in the majority of cases, the so-called post-varicella angiopathy has a monophasic evolution with spontaneous resolution or stabilization, explaining diverging diagnostic and treatment approaches. In this paper, we have addressed this problematic area by reviewing 26 published cases from the year 2000 and three unpublished cases. Post-varicella stroke is typically associated with angiopathy most often involving the initial portion of the middle cerebral artery, causing a basal ganglia stroke. It tends to occur in young immunocompetent children. Thrombophilia work-up is in general negative. Lumbar puncture was performed in 17 out of 29 cases. Viral markers were examined in 14 cases, but were positive in only eight cases. Antiviral therapy was administrated in 11 children. In this small retrospective study, the treated children's vasculopathy did not progress more favorably nor was there a better outcome compared with untreated subjects.

Cerebrospinal fluid biomarkers in patients with varicella-zoster virus CNS infections

Varicella-zoster virus (VZV) is one of our most common viruses causing central nervous system (CNS) infection with sometimes severe neurological complications. Glial fibrillary acidic protein (GFAp), light subunit of neurofilament protein (NFL) and S-100β protein are cerebrospinal fluid (CSF) biomarkers that have been used to estimate the severity of brain damage and outcome in various CNS diseases. So far, these biomarkers have not been utilised to investigate glial pathology and neuronal damage in patients with VZV CNS infections. In this prospective study, we measured CSF GFAp, NFL and S-100β as markers of brain damage in 24 patients with acute neurological manifestations and VZV DNA detected in CSF by PCR and compared with a control group (n = 14). Concentrations of CSF NFL and GFAp were increased in patients with VZV CNS infection compared with controls (p = 0.002 and p = 0.03) while levels of S-100β were reduced. In patients with VZV encephalitis the elevations of CSF NFL and GFAp were more pronounced compared with patients with other VZV CNS syndromes. No correlations between the levels of biomarkers and viral load, neurological sequels or clinical outcome were found in this limited number of patients. These results indicate that VZV induces neuronal damage and astrogliosis with more severe brain damage in patients with VZV encephalitis than in patients with other neurological complications caused by this virus.

Search for varicella zoster virus and herpes simplex virus-1 in normal human cerebral arteries

Virological confirmation of varicella zoster virus (VZV) vasculopathy is provided by presence of virus in the cerebral arteries, frequently associated with inflammation. Yet, cerebral arteries from normal subjects have never been studied for VZV DNA or antigen. We analyzed 63 human cerebral arteries from 45 subjects for VZV DNA and antigen, control herpes simplex virus (HSV)-1 DNA and antigen, and leukocyte-specific CD45 antigen. No cerebral arteries contained VZV or HSV-1 DNA or antigen; eight arteries from seven subjects contained leukocytes expressing CD45. Thus, the presence of VZV antigen in cerebral arteries of patients with stroke is likely to be clinically significant.

Varicella zoster vaccines and their implications for development of HSV vaccines

Live attenuated vaccines to prevent varicella and zoster have been available in the US for the past 17 years, with a resultant dramatic decrease in varicella incidence and a predicted future decrease in the incidence of zoster. The pathogenesis and immune responses to varicella zoster virus (VZV) as well as the safety and effectiveness of VZV vaccines are reviewed. The lack of sterilizing immunity provided by VZV vaccines has not prevented them from being safe and effective. Virological and pathological information concerning parallels and differences between VZV and herpes simplex virus (HSV) are highlighted. Although VZV and HSV are distinct pathogens, they appear to have similarities in target organs and immunity that provide an expectation of a high likelihood for the success of vaccination against HSV, and predicted to be similar to that of VZV.

Mechanisms of pediatric cerebral arteriopathy: an inflammatory debate

Arteriopathy is the leading cause of childhood arterial ischemic stroke, but its mechanisms are poorly understood. This review explores the possible role of inflammatory mechanisms and evidence for inflammatory pathophysiology in specific pediatric cerebral arteriopathies. Pathologically proven small-vessel central nervous system vasculitis provides a definitive inflammatory model where available treatments are likely improving outcomes. In contrast, a common large-vessel arteriopathy presents many features suggestive of inflammation, but definitive proof remains elusive. Recent advances and future research directions, including biomarker, neuroimaging, and pathologic approaches and how they might address these important clinical questions, are discussed.

Varicella-zoster virus vasculopathy: immune characteristics of virus-infected arteries

OBJECTIVE

Pathologic changes in varicella-zoster virus (VZV)-infected arteries include inflammation, thickened intima, and paucity of smooth muscle cells. Since no criteria have been established for early vs late VZV vasculopathy, we examined inflammatory cells and their distribution in 6 normal arteries, and 2 VZV-infected arteries 3 days after onset of disease (early) and 10 months after protracted neurologic disease (late).

METHODS

VZV-infected temporal artery obtained 3 days after onset of ischemic optic neuropathy from an 80-year-old man, VZV-infected middle cerebral artery (MCA) obtained 10 months after protracted disease from a 73-year-old man, and 5 MCAs and 1 temporal artery from normal subjects, age 22-60 years, were examined histologically and immunohistochemically using antibodies against VZV and inflammatory cell subsets.

RESULTS

In both early and late VZV vasculopathy, T cells, activated macrophages, and rare B cells were found in adventitia and intima. In adventitia of early VZV vasculopathy, neutrophils and VZV antigen were abundant and a thickened intima was associated with inflammatory cells in vaso vasorum vessels. In media of late VZV vasculopathy, viral antigen, but not leukocytes, was found. VZV was not seen in inflammatory cells. Inflammatory cells were absent in control arteries.

CONCLUSIONS

Both VZV and neutrophils exclusively in adventitia in early VZV vasculopathy indicate that disease begins there. Late VZV vasculopathy is distinguished by viral antigen without inflammation in media, revealing a human virus in an immunoprivileged arterial media. Association of thickened intima and inflammation in vaso vasorum vessels in early VZV vasculopathy support the role of virus-induced inflammation in vessel wall remodeling.

Primary and secondary central nervous system vasculitis

Central nervous system vasculitis is an increasingly recognized inflammatory brain disease causing devastating neurological deficits and psychiatric manifestations in previously healthy children. Primary central nervous system vasculitis represents an isolated inflammatory attack targeting the cerebral vessels. In contrast, in children with secondary central nervous system vasculitis, an underlying condition can be identified. The spectrum of childhood primary and secondary central nervous system vasculitis is rapidly expanding, as is the differential diagnosis including nonvasculitic inflammatory brain diseases and noninflammatory vasculopathies. Early recognition, rapid diagnostic evaluation, and initiation of treatment have led to improved morbidity and mortality. This review focuses on clinical, laboratory, and neuroimaging characteristics of the distinct subtypes of primary childhood central nervous system vasculitis, reports the etiology of secondary central nervous system vasculitis, provides an overview of the differential diagnosis, and reviews the current approaches in treatment.

Intracranial dissection mimicking transient cerebral arteriopathy in childhood arterial ischemic stroke

Transient cerebral arteriopathy is a frequent cause of childhood arterial ischemic stroke. Differentiating this condition from intracranial carotid artery dissection is challenging but important for initial treatment. We describe 4 cases from the International Pediatric Stroke Study of intracranial carotid artery dissection, initially misdiagnosed as transient cerebral arteriopathy. Presentations were abrupt, with focal neurological deficits in 4, preceding headache in 3, and minor trauma in 1. Infarcts involved the anterior circulation, and magnetic resonance angiography showed unilateral arterial stenosis/occlusion. None had evidence of dissection. All received anticoagulation or thrombolysis. Three died from refractory intracranial hypertension. Intracranial carotid artery dissection was confirmed postmortem (n = 3) and on dedicated MR wall imaging showing intramural hematoma (n = 1). In differentiating transient cerebral arteriopathy from intracranial carotid artery dissection, routine magnetic resonance angiography is unreliable and adjunctive conventional angiography, gadolinium magnetic resonance angiography, or dedicated MRI wall imaging should be considered.

The vascular effects of infection in Pediatric Stroke (VIPS) Study

Understanding the vascular injury pathway is crucial to developing rational strategies for secondary stroke prevention in children. The multicenter Vascular Effects of Infection in Pediatric Stroke (VIPS) cohort study will test the hypotheses that (1) infection can lead to childhood arterial ischemic stroke by causing vascular injury and (2) resultant arteriopathy and inflammatory markers predict recurrent stroke. The authors are prospectively enrolling 480 children (aged 1 month through 18 years) with arterial ischemic stroke and collecting extensive infectious histories, blood and serum samples (and cerebrospinal fluid, when clinically obtained), and standardized brain and cerebrovascular imaging studies. Laboratory assays include serologies (acute and convalescent) and molecular assays for herpesviruses and levels of inflammatory markers. Participants are followed prospectively for recurrent ischemic events (minimum of 1 year). The analyses will measure association between markers of infection and cerebral arteriopathy and will assess whether cerebral arteriopathy and inflammatory markers predict recurrent stroke.

Current proceedings of childhood stroke

Stroke is a sudden onset neurological deficit due to a cerebrovascular event. In children, the recognition of stroke is often delayed due to the low incidence of stroke and the lack of specific assessment measures to this entity. The causes of pediatric stroke are significantly different from that of adult stroke. The lack of safety and efficiency data in the treatment is the challenge while facing children with stroke. Nearly half of survivors of pediatric stroke may have neurologic deficits affecting functional status and quality of life. They may cause a substantial burden on health care resources. Hence, an accurate history, including onset and duration of symptoms, risk factors, and a complete investigation, including hematologic, neuroimaging, and metabolic studies is the key to make a corrective diagnosis. A prompt and optimal treatment without delay may minimize the damage to the brain.

Stroke After varicella-zoster infection: report of a case and review of the literature

Ischemic stroke is a recognized complication of varicella-zoster virus infections. We report on an immunocompetent 5-year-old girl who presented with acute neurologic deficits attributed to cerebral infarction, 3 months after varicella-zoster virus infection. Magnetic resonance imaging of the brain showed subacute ischemic lesions in the territory of the right middle cerebral artery. A literature review of 70 similar cases is reported.

A 24-year-old male with headaches

A 24-year-old man presented with a ten-day history of severe headache leading to collapse. CT studies showed filling defects involving the anterior, middle and posterior cerebral arteries and evidence of ischemia and infarction. Post-mortem examination revealed multiple cerebral infarcts secondary to an arteritic process composed of multi-nucleated giant cells, lymphocytes and histiocytes in both middle and anterior cerebral arteries and one posterior cerebral artery. Both carotid siphons and one renal artery segment were also involved. Extensive workup and stains for systemic and infectious causes were negative, leading to a diagnosis of atypical giant cell arteritis (GCA). Disseminated GCA involving extracranial arteries and the anterior, middle and posterior cerebral arteries leading to cerebral infarction has not been previously reported. We report this atypical case of disseminated GCA in a young patient with clinical features distinct from classic GCA (temporal arteritis) and discuss the differential diagnosis.

Ischemic stroke associated with adenoviral infection in a 4-year-old boy

We present a case of childhood arterial ischemic stroke associated with proven adenoviral upper respiratory tract infection in a previously healthy 4-year-old boy. Adenoviral meningitis and encephalitis have been reported repeatedly, thus confirming the neuroinvasive capability of these viruses. However, an association between adenoviral infection and arterial ischemic stroke has not been described thus far. HIV and varicella zoster virus are the only microorganisms that have been consistently associated with arterial ischemic stroke in the absence of acute central nervous system infection. In HIV-infected individuals ischemic stroke can be caused by vasculitis and hypercoagulability. Granulomatous arteritis of the vessel wall causes post-varicella cerebral infarction and ischemic stroke after herpes zoster ophthalmicus. We suggest that in our patient a post-varicella cerebral infarction-like mechanism of adenoviral spread to the affected artery wall occurred through the ophthalmic branch of the trigeminal nerve. Adenoviruses are neuroinvasive and inflamed conjunctiva might have permitted introduction of the virus into ophthalmic nerve tissue. In consequence, the stenotic lesion of the artery might have been induced by the presence of adenovirus and the subsequent inflammatory reaction. We recommend a prompt quest for adenoviral infection in all previously healthy children with fever and clinical presentation compatible with ischemic stroke, because timely diagnosis and treatment could improve the outcome and hasten neurological recovery.

The course and outcome of unilateral intracranial arteriopathy in 79 children with ischaemic stroke

Arteriopathies are the commonest cause of arterial ischaemic stroke (AIS) in children. Repeated vascular imaging in children with AIS demonstrated the existence of a ‘transient cerebral arteriopathy’ (TCA), characterized by lenticulostriate infarction due to non-progressive unilateral arterial disease affecting the supraclinoid internal carotid artery and its proximal branches. To further characterize the course of childhood arteriopathies, and to differentiate TCA from progressive arterial disease, we studied the long-term evolution of unilateral anterior circulation arteriopathy, and explored predictors of stroke outcome and recurrence. From three consecutive cohorts in London, Paris and Utrecht, we reviewed radiological studies and clinical charts of 79 previously healthy children with anterior circulation AIS and unilateral intracranial arteriopathy of the internal carotid bifurcation, who underwent repeated vascular imaging. The long-term evolution of arteriopathy was classified as progressive or TCA. Clinical and imaging characteristics were compared between both groups. Logistic regression modelling was used to determine possible predictors of the course of arteriopathy, functional outcome and recurrence. After a median follow-up of 1.4 years, 5 of 79 children (6%) had progressive arteriopathy, with increasing unilateral disease or bilateral involvement. In the others (94%), the course of arteriopathy was classified as TCA. In 23% of TCA patients, follow-up vascular imaging showed complete normalization, the remaining 77% had residual arterial abnormalities, with improvement in 45% and stabilization in 32%. Stroke was preceded by chickenpox in 44% of TCA patients, and in none of the patients with progressive arteriopathies. Most infarcts were localized in the basal ganglia. In 14 (19%) of TCA patients, transient worsening of the arterial lesion was demonstrated before the arteriopathy stabilized or improved. Thirteen TCA patients (18%) had a recurrent stroke or TIA. Thirty TCA patients (41%) had a good neurological outcome, compared with none of the five patients with progressive arteriopathy. Arterial occlusion, moyamoya vessels and ACA involvement were more frequent in progressive arteriopathies. Cortical infarct localization was significantly associated with poor neurological outcome (OR 6.14, 95% CI 1.29–29.22, P = 0.02), while there was a trend for occlusive arterial disease to predict poor outcome (OR 3.00, 95% CI 0.98–9.23, P = 0.06). Progressive arteriopathy was associated with recurrence (OR 18.77, 95%CI 1.94–181.97, P = 0.01). The majority of childhood unilateral intracranial anterior circulation arteriopathies (94%) have a course that is consistent with TCA, in which transient worsening is common. Although the arterial inflammation probably causing TCA is ‘transient’, most children are left with permanent arterial abnormalities and residual neurological deficits.

Cerebrospinal fluid analysis in the diagnosis and treatment of arterial ischemic stroke

With the advent of magnetic resonance imaging as a rapid and accurate way to diagnose arterial ischemic stroke, cerebrospinal fluid assessment is rarely performed, unless infectious or inflammatory processes are obvious. Recent advances in the understanding of the pathophysiology of childhood stroke have implicated a growing list of discrete or occult infectious and inflammatory conditions which may involve intracranial arteries and neighboring structures. Cerebrospinal-fluid assessment may allow the detection of markers identifying processes (including infectious, inflammatory, metabolic, and traumatic) potentially involved in cerebral vasculopathy and stroke. The analysis of cerebrospinal fluid in arterial ischemic strokes, including apparently idiopathic strokes, may yield essential information on pathophysiology, allowing for optimal therapeutic decisions and prognostic considerations.

Arterial ischemic stroke in children

Stroke in children is relatively rare. Advances in the clinical recognition and radiographic diagnosis of ischemic stroke have increased the frequency of the diagnosis in infants and children and have raised the need for immediate therapy. A vast amount of data has recently become available through basic research and neuroimaging techniques shedding new light on the chain of events that occur in ischemic stroke in animal models and in the adult population. Whether this new information can also be applied to the pediatric population remains to be seen, but it is likely that the active management of children with acute ischemic stroke in the near future will include brain protection, brain reperfusion, and prevention measures.

Clinical and radiological features of childhood cerebral infarction following varicella zoster virus infection

The aim of the study was to describe the clinical and radiological features of childhood post-varicella cerebral infarction (PVCI). A retrospective review was undertaken of children with arterial ischaemic stroke (AIS) who had experienced varicella zoster virus (VZV) infection within the preceding year. Twenty-four children (15 males, nine females; age range at time of VZV infection 2mo-6y) were identified, with a median of 4 months between VZV and AIS (range 1wk-12mo). All had infarction in the middle cerebral artery (MCA) territory and abnormalities of the M1 segment; arteriopathy affected other arteries in 10 children. After a median of 27 months, six patients had recurrent transient ischaemic attacks (TIA), with new infarcts in two of 22 children on re-imaging. Arterial disease improved in 11 children, was stable in four, and progressed in seven (of whom four had recurrent TIA and two had re-infarction). PVCI affects young, previously healthy children within a few months of VZV infection and is characterized by MCA territory infarction and proximal MCA disease. One quarter of patients have recurrence, usually, but not inevitably, associated with progressive arteriopathy. Treatable co-existing AIS risk factors should always be excluded. A more comprehensive diagnostic evaluation should be considered in children with AIS who do not fit the clinical and radiological profile outlined, even where there is a history of recent VZV infection.

Intrathecal aspergillosis and fusiform arterial aneurysms in an immunocompromised child: a clinico-pathological case report

CASE REPORT

We describe a 12-year-old boy with subarachnoid hemorrhage. Cerebral angiography revealed multiple fusiform intracranial arterial aneurysms. Surgical therapy other than ventricular drainage was not feasible due to the extent and pattern of pathological changes. Aspergillus antigen was found in the cerebrospinal fluid (CSF). However, cultures of urine, CSF, and samples from the upper airways were negative for Aspergillus and other fungi. The boy was immunocompromised due to prophylactic antibiotic therapy for recurrent pneumonia and continuous steroid therapy for his hemolytic anemia. There were Aspergillus antigens but no evidence of ongoing infection with the fungus was found. The patient suffered recurrent intraventricular hemorrhage and died on the 31st day after admission.

PATHOLOGICAL EXAMINATION

Pathological examination showed multiple fusiform aneurysms, hypertrophy of the intima, and destruction of the internal elastic membrane of the cerebral arteries. No fungus infiltration was detected. We speculate that the patient had previously had an Aspergillus infection, causing segmental destruction of the internal elastic membrane. However, we cannot rule out noninfectious vasculitis as possible etiology.

CONCLUSIONS

In the immunocompromised child, fusiform segmental intracranial arterial aneurysms may be secondary to the destruction of the internal elastic membrane by fungus infection. The condition may present with aneurysm rupture and subarachnoid hemorrhage. In this patient group, surgical therapy is rarely an option and the prognosis is poor.

Cerebrovascular disease and varicella in children

Varicella-associated stroke has been reported with increasing frequency in recent years. In many cases, diagnosis is difficult because of the late onset of manifestations after the acute infectious episode. Four cases of cerebrovascular disease after varicella infection were observed. Three children presented hemiparesis and one facial paresis. The neuroradiological findings comprised stenosis/occlusion of middle cerebral artery or nucleo capsular signal alteration. Because, several pathogenetic mechanisms have been proposed as the cause of stroke, the relationship between prothrombotic conditions, antipospholipid antibodies and stroke in these patients is discussed. The difficulty in defining the pathogenesis of the ischemic episode is related to problems in the choice of antithrombotic treatment, which is still not standardized and must be decided on individual basis. In the event of rapid onset of stroke after exanthem high dose antiviral therapy seems to be justified. On the basis of our experience and of literature data on varicella-associated stroke, we recommend that VZV infection be taken into account in every episode of stroke in children.

Pediatric stroke: the child is not merely a small adult

Arterial ischemic stroke and sinovenous thrombosis are a significant yet under-recognized causes of mortality and morbidity in the pediatric population. With increasingly complex etiologies yet urgency for rapid diagnosis and treatment, pediatric stroke teams likely will become the standard of care. A common terminology must be developed to avoid confusing types of acute cerebral insults--such as focal arterial ischemic stroke and global hypoxia and ischemia--that have different causes and pathophysiologic mechanisms of injury. Increased awareness of unique pediatric stroke subtypes, their clinical presentation, and their imaging findings will facilitate early identification and development of optimal treatment strategies.

[Vasculitis associated with viral infections]

VIRUSES, THE CAUSE OF VASCULITIS: Although the majority of systemic vasculitis are of unknown causes, the responsibility of a viral infection has been formally demonstrated in some of them and specific treatment can permanently cure them. Each virus incriminated accounts for a particular type of vasculitis. HEPATITIS B VIRAL INFECTION (HBV): Is the cause of polyarteritis nodosa in 36 to 50% of cases. The onset of the symptomatology is acute, usually within a few months following the infection; it is comparable to that observed in the absence of HBV infection. CRYOGLOBULINEMIA RELATED TO THE HEPATITIS C VIRUS (HCV): The clinical manifestations are those of systemic vasculitis with particular tropism for the skin (involvement generally inaugural and almost constant), peripheral nerves and the glomerula. They occur fairly late during the infection. VASCULITIS ASSOCIATED WITH HIV INFECTION: There is strong tropism for the peripheral (multi-neuritis) and central nervous system. During acute parvovirus B19 infection Vasculitis lesions have occasionally been reported following the viremic phase, generally limited to one or several flares of vascular purpura predominating on the lower limbs. FOLLOWING VARICELLA-HERPES ZOSTER INFECTION: Vasculitis occasionally develops in the form of a central neurological deficiency (locomotor deficiency with or without aphasia around one month after an ophthalmologic herpes zoster) or involving the retina or, more rarely, the skin or the kidneys. VASCULITIS ASSOCIATED WITH CYTOMEGALOVIRAL INFECTION: Predominantly observed in immunodepressed patients, vasculitis after CMV infection is diffuse and basically involving the digestive tube, notably the colon, the central nervous system and the skin. A RARE COMPLICATION OF AN HTLV1 INFECTION: Vasculitis of the retina often in the form of necrotic retinitis is often associated with spasmodic paraparessia.

THERAPEUTIC STRATEGY

For many vasculitis of viral origin, corticosteroid and immunosuppressive treatments are only indicated in second intention following failure with antiviral agents and the combination of antivirals and plasma exchanges.

Toward the definition of cerebral arteriopathies of childhood

PURPOSE OF REVIEW

To facilitate and standardize the diagnosis of cerebrovascular conditions in childhood, particularly in the field of arterial ischemic diseases.

RECENT FINDINGS

Progress in diagnostic techniques in the past decade have led to newly established etiologies for childhood stroke, most of which represent some form of vascular pathology. These advances must be integrated into a modern nomenclature system with revised definitions of stroke and arterial wall diseases-arteriopathies-in childhood.

SUMMARY

This nomenclature system is intended to facilitate and enhance clinical research in childhood stroke, particularly multicenter collaborative studies.

Radiological approach to disorders of arterial brain vessels associated with childhood arterial stroke-a comparison between MRA and contrast angiography

Recent studies of arterial ischaemic stroke in children have emphasised the higher frequency of cerebral arterial abnormalities than believed previously, explaining some of the strokes thought to have been idiopathic. Moreover, recurrent strokes are significantly more frequent in children with multiple risk factors, including those with demonstrable vascular abnormalities. Thus, cerebral arterial imaging is essential for the understanding and therapeutic approach to this pathology. Contrast angiography (CA) is the reference examination for the diagnosis of cerebral arterial abnormalities, but MR angiography (MRA) is a sensitive and non-invasive method to evaluate the vasculopathy of childhood stroke. In this article we highlight recent data concerning localisation and characterisation of arterial lesions and discuss the yield of MRA compared with CA.

Central nervous system vasculitis in children

PURPOSE OF THE REVIEW

To summarize the current literature on central nervous system vasculitis in childhood because this condition remains a diagnostic and therapeutic challenge.

RECENT FINDINGS

Central nervous system vasculitis in childhood may be primary or secondary to a variety of conditions including infections, collagen vascular diseases, systemic vasculitides, and malignancies. Conditions that result in vasospasm or are associated with noninflammatory vasculopathies may mimic the features of central nervous system vasculitis. Recent studies have described the clinical spectrum of CNS vasculitis in childhood. The most common presenting features are headaches and focal neurologic deficits. The diagnosis of central nervous system vasculitis remains particularly difficult because the available investigative modalities have limited sensitivities and specificities. The most helpful diagnostic tests include cerebrospinal fluid analysis, MRI of the brain, and angiography. However, brain biopsy may be required to diagnose small vessel vasculitis.

SUMMARY

This review summarizes recent data on primary central nervous system vasculitis and some of the secondary CNS vasculitides in children. Awareness of the presenting clinical features of CNS vasculitis should lead to consideration of the diagnosis. Awareness of the sensitivity and specificity of the various diagnostic tests should lead to the more prudent use of invasive diagnostic tests including angiography and brain biopsy.