Role of varicella-zoster virus in stroke syndromes

Motor sequela of adult and pediatric stroke: Imminent losses and ultimate gains

Stroke is the leading cause of neurological disability in the United States and worldwide. Remarkable advances have been made over the past 20 years in acute vascular treatments to reduce infarct size and improve neurological outcome. Substantially less progress has been made in the understanding and clinical approaches to neurological recovery after stroke. This chapter reviews the epidemiology, bedside examination, localization approaches, and classification of stroke, with an emphasis on motor stroke presentations and management, and promising research approaches to enhancing motor aspects of stroke recovery.

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.

Infectious Causes of Stroke

Stroke is one of the primary causes of mortality and morbidity worldwide. It can be ischemic or hemorrhagic, and the former can be due to an in-situ thrombus or a distant embolus. Despite being a rare cause, stroke can also be caused in the setting of infection. Bacterial agents are the most common cause of stroke, among other infectious agents. Until the antibiotic era, rheumatic heart disease was a predisposing risk factor of infective endocarditis. VZV is the most common cause of strokes in pediatric and adult populations. Cryptococcus and Candida spp are the most common yeasts involved in CNS infections, especially in immunocompromised patients. In COVID-19 patients, ischemic strokes are more common than hemorrhagic strokes. In this review, we will discuss the most common infectious agents, with particular emphasis on COVID-19.

Infectious Agents and Stroke: A Systematic Review

Introduction:

A major cause of injury and the second cause of death worldwide is stroke. Among several infectious agents considered as the risk factor of stroke, some pathogens demonstrated stronger robust associations with stroke. Proposing an accurate correlation between infectious microorganisms and stroke provides valuable information for early intervention and control of the infections.

Methods:

In this study, we searched the literature using the Web of Science, PMC/Medline via PubMed, and Scopus databases up to July 2018 without time and language restrictions. After quality assessment, 16 articles were included in the study. The whole data extraction process was independently conducted by two reviewers.

Results:

Based on the results of the studies, viruses, such as Hepatitis C virus (HCV), Hepatitis B virus (HBV), Human Immunodeficiency Virus (HIV), Herpes Simplex Virus Type-1, 2 (HSV-1, 2), Varicella-Zoster Virus (VZV or Chickenpox), and West Nile virus (WNV) seem to be common causes of ischemic stroke. Moreover, the association of other microbial categories, such as Streptococcus mutans (in bacteria), Toxocara spp. and Toxoplasma gondii (in parasites), and Rhizopus sp. (in fungi) with stroke was reported.

Conclusion:

Considering the adverse role of the above-mentioned microorganisms, it is necessary to implement some preventive measures for stroke treatment.

Perspectives in neonatal and childhood arterial ischemic stroke

INTRODUCTION

Over the last decade considerable advances have been made in the identification, understanding and management of pediatric arterial ischemic stroke. Such increasing knowledge has also brought new perspectives and interrogations in the current acute and rehabilitative care of these patients. Areas covered: In developed countries, focal cerebral arteriopathy is one of the most common causes of arterial ischemic stroke in childhood and imaging features are well characterized. However, there are ongoing debates regarding its underlying mechanisms, natural evolution and proper management. The implementation of thrombolytic therapy in acute pediatric stroke has been shown to be efficient in anecdotal cases but is still limited by a number of caveats, even in large tertiary centers. Finally, neonatal stroke represents a unique circumstance of possible early intervention before the onset of any neurological disability but this appears meaningful only in a selective group of neonates. Expert commentary: While perinatal stroke, a leading cause of cerebral palsy, appears to be multifactorial, a large number of childhood ischemic stroke are probably essentially triggered by infectious factors leading to vessel wall damage. Current research is aiming at better identifying risk factors in both conditions, and to define optimal acute and preventive therapeutic strategies in order to reduce significant long-term morbidity.

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.

Inflammatory markers in pediatric stroke: An attempt to better understanding the pathophysiology

BACKGROUND

The mechanisms of childhood and perinatal arterial ischemic stroke (AIS) are poorly understood. Multiple risk factors include cerebral arteriopathy, congenital cardiac disease, infection, sickle cell disease, and maternal-fetal conditions in neonates. For infections and parainfectious conditions being the most important a possible inflammatory pathophysiology has long been suspected. This pilot study aims to detect, whether there are any abnormalities of inflammatory markers associated with childhood and neonatal stroke.

METHODS

The concentration of 23 different metalloproteinases (MMPs), tissue inhibitors of MMPs (TIMPs), endothelial factors, vascular cell adhesion proteins, and cytokines in plasma were measured in 12 children with AIS, 7 healthy age matched controls and 6 full term neonates with perinatal AIS.

RESULTS

At the time of the acute event children with AIS had significantly elevated levels of MMP-9, TIMP4, IL-6, IL-8 and CRP compared to controls (p < 0.05). Except for lower IL-6 and CRP levels the pattern of children with a history of varizella-zoster virus (VZV) and other viral infections did not differ to the non-infectious group. Median levels of MMP-1, MMP-2, TIMP-1, TIMP-2, sE-selectin, sICAM-1, sVCAM-1, IL-8, IL-10, TNF-alpha, VEGF, Fetuin A were found to be higher in the neonatal group when compared with older children.

CONCLUSION

This pilot study supports the assumption of an inflammatory process and up-regulation of metalloproteinases and their inhibitors, and altered pattern of circulating pro-inflammatory cytokines, CRP and vWF levels in pediatric and neonatal AIS. It highlights the feasibility but also difficulties for similar larger future studies that should aim to clarify childhood stroke etiopathogenesis and consecutive further therapeutic options.

Vascular Complications of Varicella: Description of 4 Cases and a Review of Literature

Stroke and deep venous thrombosis are rare complications of varicella zoster infection. We report 3 cases of children with a stroke and 1 case of a boy with a deep venous thrombosis after recent chicken pox.

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.

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.

Post-varicella angiopathy: a series of 4 patients with focus on virologic and neuroimaging findings

BACKGROUND

Post-varicella angiopathy is an important cause of childhood stroke and follows a particular pattern. Specific treatment guidelines have not been developed because of a lack of epidemiological, laboratory, and neuroimaging data. Prospective randomized controlled trials evaluating different treatment strategies have not been performed, and expert opinions on diagnostic criteria, prognosis, and treatment are diverging.

METHODS

This case series describes the clinical course, laboratory, and neuroimaging findings of four children with post-varicella angiopathy, who all underwent cerebrospinal fluid assessment and received antiviral, immunosuppressive, and antiplatelet treatment.

RESULTS

Cerebrospinal fluid analysis was positive for varicella-zoster virus markers in three children. At follow-up, three children had a mild hemiparesis and one child had no neurological symptoms. Neuroimaging showed complete vascular remission in three patients and improvement in one.

CONCLUSIONS

Systematic search for virologic markers in cerebrospinal fluid will contribute to the understanding of the pathogenesis of idiopathic childhood stroke and can be considered as a prerequisite for the development of clear diagnostic criteria and relevant treatment strategies for post-varicella angiopathy. The role of antiviral and immunosuppressive medication needs to be clarified.

Infectious causes of stroke

Most infectious pathogens have anecdotal evidence to support a link with stroke, but certain pathogens have more robust associations, in which causation is probable. Few dedicated prospective studies of stroke in the setting of infection have been done. The use of head imaging, a clinical standard of diagnostic care, to confirm stroke and stroke type is not universal. Data for stroke are scarce in locations where infections are probably most common, making it difficult to reach conclusions on how populations differ in terms of risk of infectious stroke. The treatment of infections and stroke, when concomitant, is based on almost no evidence and requires dedicated efforts to understand variations that might exist. We highlight the present knowledge and emphasise the need for stronger evidence to assist in the diagnosis, treatment, and secondary prevention of stroke in patients in whom an infectious cause for stroke is probable.

Chickenpox and stroke in children: case studies and literature review

Postvaricella cerebral arteriopathy (PVCA) presents with acute haemiparesis and/or haemidistonia, caused by ischaemic lesions of internal capsule and/or basal ganglia, related to stenosis of proximal middle and/or anterior cerebral arteries. Anti-aggregant drugs are recommended to prevent thrombus expansion and recurrent stroke, but neurologic outcome is usually good regardless of the therapeutic approach.

CONCLUSION

Chickenpox should be considered in differential diagnosis of ischaemic stroke in healthy children who fit the clinical and radiological typical profile of PVCA.

[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.

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.

[Cerebrovascular disease in childhood: a retrospective analysis of hospital admissions in a tertiary hospital in the community of Valencia in the last ten years]

INTRODUCTION

There has been increasing interest in stroke in children in the last few years. A literature review produced little information on risk factors and other clinical questions. The aim of this study is to describe the characteristics of stroke in children, mainly in order to identify the risk factors, clinical presentation and outcomes.

PATIENTS AND METHODS

A retrospective study was conducted on patients admitted to the Hospital La Fe in Valencia between January 2000 to September 2010 with the diagnosis of ischaemic or haemorrhagic stroke.

RESULTS

A total of 76 patients were identified, of whom 44.7% had an ischaemic stroke and 55.3% had a haemorrhagic one. The average age of presentation was 6.8 years; 8.4 years for haemorrhagic strokes and 4.7 years for ischaemic strokes. Headache was the most frequent symptom of presentation. The most frequent risk factor was vascular malformations in haemorrhagic cerebral stroke, and vascular and cardiac disorders in ischaemic stroke. A study of prothrombotic factors was conducted on 34 patients, which was positive in 64.7% of them. As regards outcome, 17% of the patients died; only 3 patients had a secondary epilepsy, and 31% and 60% of the haemorrhagic and ischaemic stokes, respectively, had a hemiparesis.

CONCLUSIONS

In this study we identified the principal risk factors as well as, the age of presentation, symptomatology and outcome. We would like to emphasise that the age of presentation was earlier in ischaemic strokes than in haemorrhagic ones.

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.

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.

Varicella vaccination and ischemic stroke in children: is there an association?

BACKGROUND

Ischemic stroke is a known complication of varicella disease. Although there have been case reports of ischemic stroke after varicella vaccination, the existence and magnitude of any vaccine-associated risk has not been determined. OBJECTIVE. The purpose of this work was to determine whether varicella vaccination is associated with an increased risk of ischemic stroke and encephalitis in children within 12 months after vaccination.

PATIENTS AND METHODS

We conducted a retrospective cohort study based on computerized data from children 11 months through 17 years old enrolled for > or =12 months in the Vaccine Safety DataLink from 1991 through 2004. International Classification of Disease codes identified cases of ischemic stroke (433-436, 437.1, 437.4, 437.6, 437.8-437.9) and encephalitis (052.0, 323.5, 323.8-9). Cox regression was used to model the risk in the 12 months after vaccination relative to all other person-time. Covariates included calendar time, gender, and stroke risk factors (eg, sickle cell disease).

RESULTS

Varicella vaccine was administered to 35.3% of the 3.2 million children in the cohort. There were 203 new inpatient ischemic stroke diagnoses, including 8 that occurred within 12 months after vaccination; there was no temporal clustering. The adjusted stroke hazard ratio was not elevated during any of the time periods in the 12 months after vaccination. Stroke was strongly associated with known risk factors such as sickle cell disease and cardiac disease. None of the 243 encephalitis cases occurred during the first 30 days after vaccination, and there was no association between encephalitis and varicella vaccination at any time in the 12 months after vaccination.

CONCLUSION

Our retrospective cohort study of >3 million children found no association between varicella vaccine and ischemic stroke.

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.

Varicella encephalopathy in immunocompetent children

Two previously healthy girls presented acute encephalopathy due to varicella, with severe alteration of the conscious level and seizures. Both patients improved progressively after 15 days, with complete clinical recovery.

Recommendations for the management of herpes zoster

The objective of this article is to provide evidence-based recommendations for the management of patients with herpes zoster (HZ) that take into account clinical efficacy, adverse effects, impact on quality of life, and costs of treatment. Systematic literature reviews, published randomized clinical trials, existing guidelines, and the authors' clinical and research experience relevant to the management of patients with HZ were reviewed at a consensus meeting. The results of controlled trials and the clinical experience of the authors support the use of acyclovir, brivudin (where available), famciclovir, and valacyclovir as first-line antiviral therapy for the treatment of patients with HZ. Specific recommendations for the use of these medications are provided. In addition, suggestions are made for treatments that, when used in combination with antiviral therapy, may further reduce pain and other complications of HZ.

Central nervous system vasculitis in children

Central nervous system (CNS) vasculitis is an increasingly recognized, often devastating inflammatory brain disease of children and adults. In primary or isolated CNS vasculitis/angiitis of childhood (cPACNS), the vascular inflammation is limited to the brain and spinal cord. Secondary CNS vasculitis occurs in a variety of conditions including infections, collagen vascular diseases, systemic vasculidities, and malignancies. Mimics of CNS vasculitis in children include dissections and noninflammatory vasculopathies. Diagnosis of primary CNS vasculitis in both adults and children is based on the Calabrese criteria. This review summarizes recent data on CNS vasculitis in children; reviews the clinical spectrum at presentation and the role of laboratory tests, neuroimaging, and brain biopsy; and discusses treatment strategies, outcome data, and overlapping conditions of cPACNS.

Stroke in Childhood

BACKGROUND

Childhood stroke is increasingly recognized as an important cause of morbidity and mortality. Risk factors for stroke in childhood are different than those traditionally seen in adults.

REVIEW SUMMARY

This review summarizes, in brief, the epidemiology, risk factors, evaluation, treatment, outcome, and recurrence risk of children with arterial ischemic stroke (AIS). Areas of controversy and those that require further study are highlighted. Tables summarizing important points of the history, physical examination, and diagnostic evaluation of AIS are provided.

CONCLUSIONS

Children with stroke should be carefully evaluated for risk factors and possible etiology of stroke. At the present time, treatment is based upon extrapolation from the adult literature and expert opinion, as no evidence-based guidelines exist, except in sickle cell anemia. International, multicenter trials are beginning and should provide some answers over the next few years.

Accidents vasculaires cérébraux multiples et primo-infection varicelleuse chez un adulte

INTRODUCTION

Chickenpox is considered as a high risk factor for developing stroke in childhood, but descriptions in adult are exceptional (only three cases reported, to our knowledge).

CASE REPORT

A 37-year-old man presented with a chickenpox eruption, followed by a right parietal and a left occipital infarcts, associated with multiple lacunae. There was no coagulation disorder, no hypertension or cardiovascular disorder. Cerebral angiography showed an irregular narrowing of the right internal parietal artery and vascular defects in right parietal and left occipital areas. The diagnosis of VZV-related vasculitis was evoked. White cell count, serology and VZV PCR were negative in the cerebrospinal fluid. Clinical improvement was observed after treatment by corticosteroids and aciclovir.

CONCLUSION

Chickenpox is a rare cause of cerebral vasculitis. Involvement of both medium and small vessels was present here, contrary to other adult case reports in the literature. Hematogenous dissemination of the virus responsible for cerebral vasculitis seems to be the most probable pathophysiological mechanism.

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.

Infectious and inflammatory disorders of the circulatory system and stroke in childhood

The role of infectious and inflammatory causes of stroke is much more significant in children than in adults. Conversely, that of atherosclerotic disease, ischaemic heart disease and hypertensive haemorrhages has a lesser prominence in children. Bacterial meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae, or Neiserria meningitidis has been known to cause stroke in children. The mechanism appears to be the spread of meningeal inflammation to involve the walls of intracranial vessels, resulting in arterial thrombosis with ischaemia or rupture with haemorrhage. Other infections caused by atypical bacterial agents such as Mycoplasma tuberculosis and viral agents such as varicella-zoster virus have also been well documented as causes of stroke. Non-infectious, inflammatory causes of stroke, such as collagen vascular disease and primary angiitis of the central nervous system, have been reported in children as well as adults. In this review, we will focus on recent advances in the field of childhood stroke caused by infectious and inflammatory disorders.

Encephalitis related to primary varicella-zoster virus infection in immunocompetent children

INTRODUCTION

Encephalitis is a rare complication of primary varicella-zoster virus (VZV) infection in immunocompetent children.

METHODS

The clinical and laboratory findings of two girls with VZV-related encephalitis are reported.

RESULTS

Both children presented with focal epileptic seizures, corresponding to cortical/subcortical as well as white matter lesions. The first showed a typical vesicular skin rash. She was easily diagnosed and made a rapid recovery during acyclovir and steroid treatment. In the second girl, a preceding measles-mumps-rubella virus vaccination and the absence of skin vesicles were misleading with respect to the diagnosis, which was finally proven by IgG seroconversion and intrathecal synthesis of IgG antibodies to VZV. She developed left parieto-occipital tissue necrosis and recovered only transiently during initial acyclovir/steroid treatment. Eight weeks after onset, progressive white matter demyelination and the occurrence of erythema nodosum in the lower limbs necessitated a second 4-month course of oral steroids. The VZV PCR from cerebrospinal fluid was negative in both children.

CONCLUSIONS

Primary VZV infection may cause severe encephalitis that may occur without skin vesicles and lead to a chronic course with systemic vasculitis. The coincidence of vaccination and neurologic diseases offers no proof per se of a causal relationship.

Varicella-zoster virus acquired at 4 months of age reactivates at 24 months and causes encephalitis

Varicella-zoster virus (VZV) reactivation in the brain caused encephalitis in a 2-year-old immunocompetent child who had chickenpox 20 months before. Radiologic findings were consistent with large to medium-vessel-vasculitis. VZV-DNA was detected in cerebrospinal fluid. Early acquisition of VZV may predispose to major neurologic complications that can occur years after the primary infection.