Varicella-zoster virus DNA in CSF and arteries in delayed contralateral hemiplegia: evidence for viral invasion of cerebral arteries

Headaches and Vasculitis

Vasculitis refers to heterogeneous clinicopathologic disorders that share the histopathology of inflammation of blood vessels. Unrecognized and therefore untreated, vasculitis of the nervous system leads to pervasive injury and disability making this a disorder of paramount importance to all clinicians. Headache may be an important clue to vasculitic involvement of central nervous system (CNS) vessels. CNS vasculitis may be primary, in which only intracranial vessels are involved in the inflammatory process, or secondary to another known disorder with overlapping systemic involvement. Primary neurologic vasculitides can be diagnosed with assurance after intensive evaluation that incudes tissue confirmation whenever possible.

Infection may play an important role in the pathogenesis of alveolar osteonecrosis following facial herpes zoster: a case report and literature review

BACKGROUND

Herpes zoster (HZ) is one of the most common skin diseases caused by viruses. Facial HZ develops when the varicella-zoster virus affects the trigeminal nerve, and alveolar osteonecrosis is a rare complication. However, the exact pathogenesis of postherpetic alveolar osteonecrosis remains unclear.

CASE DESCRIPTION

We encountered a patient who presented to the dermatology clinic with facial HZ and tooth exfoliation in the upper right jaw, and panoramic radiography revealed decreased bone density and poor alveolar socket healing in his right maxilla. Biopsy of the alveolar process revealed fragments of nonvital lamellar bone, which were devoid of osteoblasts and osteocytes and were surrounded by numerous neutrophils and bacterial aggregates. Thus, the diagnosis of alveolar osteonecrosis following facial HZ was confirmed. He then underwent resection of the osteonecrotic tissue. The pathological findings of postoperative tissue were similar to those of previous biopsies. Varicella-zoster virus and multiple types of bacteria were detected through next-generation sequencing, and the species of bacteria were consistent with the results of bacterial culture. Antibiotics and valaciclovir were administered during the perioperative period. The patient showed good recovery at the 9-month follow-up.

CONCLUSIONS

The coexistence of bacterial and viral infection may play an important role in the pathogenesis of alveolar osteonecrosis following HZ. To our knowledge, we are the first to directly explore microbial pathogens in a case of postherpetic alveolar osteonecrosis through next-generation sequencing and bacterial culture. We recommend that oral examinations be carefully conducted for patients who are diagnosed with facial HZ, even if their facial rashes have faded away. We suggest that a prolonged and full-dose antiviral therapy course may be beneficial for the treatment of facial HZ with intraoral lesions. The implementation of dental preventive measures should be considered for patients with facial HZ. The application of antibiotics and excision of necrotic bone may reduce the abundance of bacteria in lesions and improve wound healing.

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.

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.

A white circular-spot pattern of iridian atrophy associated with Varicella-zoster virus and Toxoplasma gondii coinfection: a case report

Background

We report a case of white circular spots of iridian atrophy, which we will call “polka dots” pattern, as a rare ophthalmological finding associated with uveitis secondary to varicella-zoster virus and Toxoplasma gondii coinfection in a male patient in Bogotá, Colombia.

Case presentation

We present de case of a 53-year-old Colombian male patient with a diagnosis of anterior uveitis in his left eye due to varicella-zoster virus and Toxoplasma gondii coinfection documented by polymerase chain reaction analysis. He presented with multiple areas of superficial white circular spots of iridian atrophy in 360º, some with deeper atrophy where the stroma fibers were visualized and only a small punctate defect of transillumination was evident. This rare pattern of iridian atrophy has not been previously described in cases of uveitis in the literature.

Conclusions

This is the first case reporting the findings of superficial “polka dots” pattern iridian atrophy in 360° secondary to anterior uveitis due to the coinfection of a virus and a parasite. The identification of similar clinical cases may lead to early initiation of systemic treatment in these patients.

Ischemic Stroke due to Virologically-Confirmed Varicella Zoster Virus Vasculopathy: A Case Series

BACKGROUND

Limited data are available regarding the characteristics and prognosis of patients with stroke due to varicella zoster virus (VZV) vasculopathy.

METHODS

We studied 4 patients (2 men and 2 women; age, 38-63 years) from a single center who developed acute ischemic stroke due to VZV vasculopathy. The virological diagnosis was confirmed by detecting VZV DNA and/or the IgG antibody to VZV in the cerebrospinal fluid.

RESULTS

Three patients were taking immunosuppressive agents, including prednisolone and/or methotrexate, at baseline. Each patient had a characteristic skin rash prior to stroke, with the interval from rash to stroke onset ranging from 13 to 122 days. Two patients experienced antecedent cranial nerve palsies; one had the third, seventh, ninth, and 10th nerve palsies and the other had the fourth nerve palsy before stroke. Cerebral infarctions were located in the anterior circulation lesion (n = 1), in the posterior circulation lesion (n = 2), and in both lesions (n = 1). Intracranial arterial stenosis was only identified in one patient on magnetic resonance angiography. A high plasma d-dimer level was detected in 1 patient, whereas high β-thromboglobulin and platelet factor 4 levels were detected in 2 patients. As a result of combined therapies with acyclovir, steroid, and antithrombotic agents, neurological symptoms markedly improved in 3 patients, whereas 1 patient was left with moderate hemiplegia.

CONCLUSIONS

Cranial nerve palsies may be prodromal symptoms of VZV-associated stroke. Increased levels of thrombotic markers may support the use of antithrombotic agents, although the benefit of combined treatment should be determined through larger studies.

Significant Associations of Neurological Complications of Herpes Zoster With Stroke in Rheumatoid Arthritis Patients

BACKGROUND

Accumulating evidence suggests an increased risk of stroke after herpes zoster (HZ). This risk is elevated in immunocompromised patients. The incidence of HZ in Asia is higher than in Western countries. However, the epidemiology of HZ and HZ-related stroke among rheumatoid arthritis (RA) patients in Asia remains unclear.

METHODS AND RESULTS

We conducted a retrospective cohort study using a population-based database to investigate the epidemiology of HZ in RA patients in Taiwan during the period of 2000-2011. A total of 27 609 newly diagnosed and eligible RA cases were identified, and 110 436 non-RA cases were matched for age and sex at a ratio of 4:1. HZ risk increased by 2.53-fold (P<0.0001) in RA patients compared with the general population. Exposure to corticosteroids (adjusted odds ratio=1.73, P<0.0001), adalimumab (adjusted odds ratio=1.61, P=0.002), and rituximab (adjusted odds ratio=2.06, P=0.008) was associated with an increased risk of HZ in RA patients. A significant association between the use of methotrexate or corticosteroids and HZ risk was dose-dependent (P_trend<0.0001). Elevated risk of stroke was observed in RA patients with HZ (adjusted hazard ratio=1.27, P=0.047), particularly in those with neurological complications (adjusted hazard ratio=1.54, P=0.015). A 2.30-fold significantly increased risk of stroke within 90 days after HZ occurrence was observed in RA patients compared with those without HZ (P=0.02). Furthermore, death risk increased in RA patients with HZ (adjusted hazard ratio=1.18, P=0.026).

CONCLUSIONS

The risk of HZ and HZ-related stroke has increased in RA patients. Monitoring the occurrence of HZ in RA patients and preventing HZ-related stroke or mortality during a specific immunosuppressive therapy are important.

Intracranial vessel wall imaging for evaluation of steno-occlusive diseases and intracranial aneurysms

Cerebrovascular diseases have traditionally been classified, diagnosed and managed based on their luminal characteristics. However, over the past several years, several advancements in MRI techniques have ushered in high-resolution vessel wall imaging (HR-VWI), enabling evaluation of intracranial vessel wall pathology. These advancements now allow us to differentiate diseases which have a common angiographic appearance but vastly different natural histories (i.e. moyamoya versus atherosclerosis, reversible cerebral vasoconstriction syndrome versus vasculitis, stable versus unstable intracranial aneurysms). In this review, we detail the anatomical, histopathological and imaging characteristics of various intracranial steno-occlusive diseases and types of intracranial aneurysms and describe the role that HR-VWI can play in diagnosis, risk stratification and treatment.

Varicella-zoster virus (VZV) DNA in serum of patients with VZV central nervous system infections

OBJECTIVES

Varicella-zoster virus (VZV) is a common viral agent causing central nervous system (CNS) infections, normally diagnosed by detection of VZV DNA in cerebrospinal fluid (CSF). Our aim was to investigate trends in VZV DNAemia in VZV CNS infections, which could potentially contribute to diagnosis and secondly, correlate the amount of VZV DNA in serum to severity of disease.

METHODS

Seventy-two patients with VZV CNS infections diagnosed by detection of VZV DNA in CSF and concomitant neurological symptoms were included. The amount of VZV DNA was measured by real-time PCR in paired serum and CSF samples and compared to a control group of herpes zoster (n = 36).

RESULTS

An increased amount of VZV DNA was detected in serum in patients with encephalitis compared to patients with meningitis or Ramsay-Hunt syndrome, respectively (p = 0.003 and p = 0.024). A greater proportion of patients with VZV CNS infections and detectable VZV DNA in serum had ongoing rash compared to those without detectable VZV DNA in serum (p ≤ 0.001). The viral load in serum of patients with neurological symptoms was lower compared to in patients with herpes zoster without neurological symptoms (p ≤ 0.001) and only 32/72 of the patients with VZV CNS disease had VZV DNA detected in serum.

CONCLUSION

Increased amount of VZV DNA in serum of patients with VZV CNS infections seems associated with encephalitis and ongoing rash. Additionally, viral DNA analysis by PCR in serum may be a helpful diagnostic tool although viral DNA analysis by PCR in CSF is the method of choice for diagnosis.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Varicella-Zoster Virus Vasculopathy: A Case Report Demonstrating Vasculitis using Black-Blood MRI

Infections are rare but important causes of stroke. Among these, varicella zoster virus has been known to cause ischemic stroke. During an attack of herpes zoster ophthalmicus, it has been hypothesized that the virus replicates in the trigeminal ganglion and travels via the trigeminal nerve centrally to cause cerebral vasculopathy. Here we present a case of a 69 year-old Caucasian immunocompromised woman who suffered recurrent ischemic infarcts within the same vascular distribution following an episode of zoster ophthalmicus three months prior. An imaging technique termed black-blood magnetic resonance imaging was utilized to aid in the diagnosis of cerebral vasculitis. The case is used to provide a literature review of the pathogenesis, diagnosis, and treatment of cerebral varicella zoster vasculopathy. In situations where an isolated unilateral cerebral vasculopathy is identified, neurologists are urged to consider varicella zoster as a treatable etiologic agent, as untreated vasculopathy can lead to further strokes.

Headaches and vasculitis

Vasculitis is a spectrum of clinicopathologic disorders defined by inflammation of arteries of veins of varying caliber with variable tissue injury. Headache may be an important clue to vasculitic involvement of central nervous system (CNS) vessels. CNS vasculitis may be primary, in which only intracranial vessels are involved in the inflammatory process, or secondary to another known disorder with overlapping systemic involvement. A suspicion of vasculitis based on the history, clinical examination, or laboratory studies warrants prompt evaluation and treatment to forestall progression and avert cerebral ischemia or infarction.

Vessel wall enhancement in herpes simplex virus central nervous system vasculitis

Infection is a well-known cause of cerebral vasculopathy and vasculitis. We report a 36-year-old woman with cerebral vasculitis and ischemic stroke secondary to herpes simplex virus (HSV). MRI studies revealed a pontine stroke with basilar artery stenosis and vessel wall gadolinium enhancement. This case demonstrates the ability of HSV to cause a focal brainstem vasculitis and the utility of enhanced MRI in the diagnosis of stroke related to HSV central nervous system vasculitis.

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.

Primary central nervous system vasculitis: pathology and mechanisms

Primary vasculitis of the central nervous system (PCNSV) is a rare and diagnostically challenging form of vasculitis limited to the brain and/or spinal cord. It is a complex and often severe disease with multifaceted clinical and pathological appearances, suggesting multiple disease subtypes and the potential existence of multiple etiologic pathways. We describe in detail the clinical, imaging, and neuropathological findings of PCNSV summarizing literature data and our observations from a cohort of 131 patients diagnosed at Mayo Clinic over a 25-year period (1983-2007). Unlike systemic vasculitis, little is known regarding PCNSV pathogenesis and the involved immunological mechanisms. Increased recognition of the disease spectrum and in-depth characterization of its histopathologic and immunological phenotype will be critical to eventually understanding the underlying derangements and mechanisms driving PCNSV. Improved understanding of the pathogenetic mechanisms of the disease may also help determine whether the different histologic patterns and clinical subsets represent more than one disease and ultimately may permit development of novel diagnostic and therapeutic strategies for it.

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.

Infectious vasculopathy of intracranial large- and medium-sized vessels in neurological intensive care unit: a clinico-radiological study

BACKGROUND

Infections are a well-known cause of cerebral vasculopathy and vasculitis. We aimed to analyze the frequency of intracranial vasculopathy attributable to infection, the spectrum of causative microorganisms, imaging, and cerebrospinal fluid (CSF) characteristics as well as clinical course and outcome.

METHODS

We used our institution's medical record system to identify all patients diagnosed with nonatherosclerotic central nervous system vasculopathy from January 1, 1999 through February 28, 2009. We reviewed their clinical charts, imaging data, and results of CSF studies.

RESULTS

Twenty-five adult patients with nonatherosclerotic cerebral vasculopathy of large- and medium-sized intracranial vessels were identified. Eight patients had vasculopathy attributable to infection (32%). The underlying pathologies were acute bacterial meningitis (n = 4), varicella zoster virus (VZV) infection (n = 2), borreliosis (n = 1), and syphilis (n = 1). In six patients, magnetic resonance angiography was performed and showed vasculopathic changes in all patients examined (100%). In both patients with VZV-associated vasculopathy, the arterial wall enhanced on magnetic resonance imaging. The CSF examination of the patients with infectious vasculopathy showed a significantly higher white blood cell count. The outcome of the infectious cohort was unfavorable with one death, two patients with locked-in syndrome, and five patients discharged from intensive care with severe neurological deficits.

CONCLUSION

In this cohort, one-third of all cases of nonatherosclerotic vasculopathy were due to infectious vasculopathy of large and medium intracranial vessels.

Severe meningoencephalitis due to late reactivation of Varicella-Zoster virus in an immunocompetent child

Recurrent reactivation of latent Varicella-Zoster virus may cause various neurological complications including encephalitis, myelitis, stroke episodes, and meningitis. It occurs mainly in elderly or immunocompromised patients and is very rare in children. We report a 14-year girl who presented with meningoencephalitis due to reactivation of Varicella-Zoster virus 10 years after she had chickenpox and 4 years after she had zoster. Characteristic skin lesions of varicella were absent. Varicella-Zoster virus DNA was detected in cerebrospinal fluid and magnetic resonance imaging (MRI) findings were consistent with small vessel cerebral vasculitis. Treatment with acyclovir and high dose methylprednisolone resulted in near-complete neurological recovery. Although rare, Varicella-Zoster virus may reactivate to cause significant central nervous system disease even in immunocompetent children. Diagnosis depends on a high degree of suspicion because the typical rash may not associate the disease. Characteristic lesions on MRI and the presence of Varicella-Zoster virus DNA in cerebrospinal fluid are key findings for the correct diagnosis.

Neurologic manifestations of varicella zoster virus infections

Varicella zoster virus (VZV) causes acute viral exanthema in childhood, becomes latent, and can reactivate years later to produce neurologic disease. Primary VZV infection is associated with acute cerebellitis and stroke, particularly in childhood. VZV reactivation may result in neuropathy, myelitis, stroke, and encephalitis, the latter two syndromes the result of small and large vessel vasculopathy. Prompt diagnosis and treatment are critical to minimize morbidity in herpes zoster as well as morbidity and death in VZV vasculitis and encephalitis. Detection of anti-VZV antibodies in cerebrospinal fluid is the most sensitive method of diagnosing varicella infection of the nervous system. Despite the advent of the VZV vaccine, varicella remains a significant cause of neurologic morbidity.

Varicella zoster virus vasculopathies: diverse clinical manifestations, laboratory features, pathogenesis, and treatment

Vasculopathies caused by varicella zoster virus (VZV) are indicative of a productive virus infection in cerebral arteries after either reactivation of VZV (shingles) or primary infection (chickenpox). VZV vasculopathy can cause ischaemic infarction of the brain and spinal cord, as well as aneurysm, subarachnoid and cerebral haemorrhage, carotid dissection, and, rarely, peripheral arterial disease. VZV vasculopathy in immunocompetent or immunocompromised individuals can be unifocal or multifocal with deep-seated and superficial infarctions. Lesions at the grey-white matter junction on brain imaging are a clue to diagnosis. Involvement of both large and small arteries is more common than that of either alone. Most patients have a mononuclear cerebrospinal fluid pleocytosis, often with red blood cells. Cerebrospinal fluid pleocytosis and rash are absent in about a third of cases. Anti-VZV IgG antibody in the cerebrospinal fluid is found more frequently than VZV DNA. In recent years, the number of recognised VZV vasculopathies has grown, and accurate diagnosis is important for the effective treatment of these disorders.

A 46-year-old female presenting with worsening headache, nuchal rigidity and a skin rash in varicella zoster virus meningitis: a case report

Varicella zoster virus causes two distinct clinical diseases. Varicella is the primary infection and results from exposure of a person susceptible to the virus. The virus remains latent in cranial nerve ganglia, dorsal root ganglia, and autonomic ganglia along the entire neuraxis. Years later, in association with a decline in cell-mediated immunity in the elderly and immuno-compromised, varicella zoster virus reactivates and can cause a wide range of neurologic disease, including herpes zoster (‘shingles’), postherpetic neuralgia, vasculopathy, myelopathy, retinal necrosis, cerebellitis, and zoster sine herpete. Herpes zoster is associated with numerous neurologic complications and varied presentations. Patients who have a dermatomal distribution of varicella zoster virus and who have headaches should be considered to have VZV meningitis. Virologic confirmation requires testing the cerebrospinal fluid for varicella zoster virus deoxyribonucleic acid via polymerase chain reaction. The application of polymerase chain reaction to the cerebrospinal fluid can be used to detect varicella zoster virus deoxyribonucleic acid and, therefore, infections of the central nervous system. We present a case report of a 46-year-old female who initially presented with worsening headache, nuchal rigidity, fever, and a skin rash, who was subsequently found to have varicella zoster meningitis.

The neurotropic herpes viruses: herpes simplex and varicella-zoster

Herpes simplex viruses types 1 and 2 (HSV1 and HSV2) and varicella-zoster virus (VZV) establish latent infection in dorsal root ganglia for the entire life of the host. From this reservoir they can reactivate to cause human morbidity and mortality. Although the viruses vary in the clinical disorders they cause and in their molecular structure, they share several features that affect the course of infection of the human nervous system. HSV1 is the causative agent of encephalitis, corneal blindness, and several disorders of the peripheral nervous system; HSV2 is responsible for meningoencephalitis in neonates and meningitis in adults. Reactivation of VZV, the pathogen of varicella (chickenpox), is associated with herpes zoster (shingles) and central nervous system complications such as myelitis and focal vasculopathies. We review the biological, medical, and neurological aspects of acute, latent, and reactivated infections with the neurotropic herpes viruses.

Le zona et ses complications neurologiques

INTRODUCTION

Herpes zoster is a disease which occurs secondary to the reactivation of varicella-zoster virus (VZV). Its frequency is high in the general population.

STATE OF ART

Herpes zoster leads to numerous complications, among which there were neurological peripheral or central lesions. Antiviral treatment must be instituted, particularly if neurological complications develop, as soon as possible. Corticosteroid therapy can be used, especially in Ramsay-Hunt syndrome or central nervous system involvement.

CONCLUSION

Herpes-zoster is a frequent disease which can lead to serious neurological complications. Early treatment is necessary in order to improve functional outcome.

The expanding spectrum of herpesvirus infections of the nervous system

Herpesviruses cause various acute, subacute, and chronic disorders of the central (CNS) and peripheral (PNS) nervous systems in adults and children. Both immunocompetent and immunocompromised individuals may be affected. Zoster (shingles), a result of reactivation of varicella zoster virus (VZV), is the most frequent neurologic complication. Other neurological complications include encephalitis produced by type I herpes simplex virus (HSV-1), and less frequently HSV-2, as well as by VZV and cytomegalovirus (CMV). Acute meningitis is seen with VZV and HSV-2, and benign recurrent meningitis with HSV-2. Combinations of meningitis/ encephalitis and myelitis/radiculitis are associated with Epstein Barr Virus (EBV); myelitis with VZV, CMV, EBV, and HSV-2; and ventriculitis/encephalitis with VZV and CMV. Brainstem encephalitis due to HSV and VZV, and polymyeloradiculitis due to CMV are well documented. HHV-6 produces childhood exanthem subitum (roseola) and febrile convulsions. Immunocompetent and immunocompromised hosts manifest different incidences and patterns of herpesvirus infections. For example, stroke due to VZV-mediated large vessel disease (herpes zoster ophthalmicus) occurs predominantly in immunocompetent hosts, while small vessel disease (leukoencephalitis) and ventriculitis develop almost exclusively in immunocompromised patients. EBV-associated primary CNS lymphomas also are restricted to immunosuppressed individuals. Recent large CSF PCR studies have shown that VZV, EBV, and CMV more frequently produce meningitis, encephalitis, or encephalopathy in immunocompetent hosts than was formerly realized. We review herpesvirus infections of the nervous system and illustrate the expanding spectrum of disease by including examples of a 75-year-old male on steroid treatment for chronic lung disease with fatal HSV-2 meningitis and an 81-year-old male with myasthenia gravis, long-term azathioprine use, and an EBV-associated primary CNS lymphoma.

Clinical and molecular pathogenesis of varicella virus infection

Varicella zoster virus (VZV) is a neurotropic human herpesvirus that infects nearly all humans and causes chickenpox (varicella). After chickenpox, VZV becomes latent in cranial nerve, dorsal root, and autonomic nervous system ganglia along the entire neuraxis. Virus reactivation produces shingles (zoster), characterized by pain and rash usually restricted to 1-3 dermatomes. Zoster is often complicated by postherpetic neuralgia (PHN), pain that persists for months to years after rash resolves. Virus may also spread to the spinal cord and blood vessels of the brain, producing a unifocal or multifocal vasculopathy, particularly in immunocompromised individuals. The increased incidence of zoster in elderly and immunocompromised individuals appears to be due to a VZV-specific host immunodeficiency. PHN may reflect a chronic VZV ganglionitis, and VZV vasculopathy is due to productive virus infection in cerebral arteries. Strategies that might boost host cell-mediated immunity to VZV are discussed, as well as the physical state of viral nucleic acid during latency and the possible mechanisms by which herpesvirus latency is maintained and virus is reactivated. A current summary of varicella latency and pathogenesis produced by simian varicella virus (SVV), the counterpart of human VZV, points to the usefulness of a primate model of natural infection to study varicella latency, as well as the experimental model of intratracheal inoculation to study the effectiveness of antiviral agents in driving persistent varicella virus into a latent state.

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.

Multiple cerebral infarcts due to varicella-zoster virus large-vessel vasculopathy in an immunocompetent adult without skin involvement

We report the case of a 52-year-old immunocompetent man with varicella-zoster virus large-vessel vasculopathy and multiple bilateral cerebral infarcts who had no history of skin involvement. Etiologic diagnosis was made by isolation of varicella-zoster virus from a cerebrospinal fluid specimen. The patient had marked improvement in mental status after acyclovir therapy was initiated.

Inflammation and infection in clinical stroke

Stroke has enormous clinical, social, and economic implications, and demands a significant effort from both basic and clinical science in the search for successful therapies. Atherosclerosis, the pathologic process underlying most coronary artery disease and the majority of ischemic stroke in humans, is an inflammatory process. Complex interactions occur between the classic risk factors for atherosclerosis and its clinical consequences. These interactions appear to involve inflammatory mechanisms both in the periphery and in the CNS. Central nervous system inflammation is important in the pathophysiologic processes occurring after the onset of cerebral ischemia in ischemic stroke, subarachnoid hemorrhage, and head injury. In addition, inflammation in the CNS or in the periphery may be a risk factor for the initial development of cerebral ischemia. Peripheral infection and inflammatory processes are likely to be important in this respect. Thus, it appears that inflammation may be important both before, in predisposing to a stroke, and afterwards, where it is important in the mechanisms of cerebral injury and repair. Inflammation is mediated by both molecular components, including cytokines, and cellular components, such as leukocytes and microglia, many of which possess pro- and/or antiinflammatory properties, with harmful or beneficial effects. Classic acute-phase reactants and body temperature are also modified in stroke, and may be useful in the prediction of events, outcome, and as therapeutic targets. New imaging techniques are important clinically because they facilitate dynamic evaluation of tissue damage in relation to outcome. Inflammatory conditions such as giant cell arteritis and systemic lupus erythematosus predispose to stroke, as do a range of acute and chronic infections, principally respiratory. Diverse mechanisms have been proposed to account for inflammation and infection-associated stroke, ranging from classic risk factors to disturbances of the immune and coagulation systems. Considerable opportunities therefore exist for the development of novel therapies. It seems likely that drugs currently used in the treatment of stroke, such as aspirin, statins, and modulators of the renin-angiotensin-aldosterone system, act at least partly via antiinflammatory mechanisms. Newer approaches have included antimicrobial and antileukocyte strategies. One of the most promising avenues may be the use of cytokine antagonism, for example, interleukin-1 receptor antagonist.

Varicella-zoster virus: atypical presentations and unusual complications

Varicella-zoster virus (VZV) is the etiologic agent of varicella (primary infection) and herpes zoster (reactivation of latent infection). Although varicella is most often a relatively benign and self-limited childhood illness, the disease can be associated with a variety of serious and potentially lethal complications in both immunocompetent and immunocompromised persons. One complication of varicella that appears to be increasing in frequency is serious bacterial soft tissue infections caused by group A streptococci. Issues related to management of varicella become especially complex when varicella involves pregnant women or susceptible neonates. Herpes zoster can be associated with a variety of neurologic complications, including a syndrome of delayed contralateral hemiparesis. Neurologic complications of herpes zoster, including chronic encephalitis, occur with increased frequency in AIDS patients. VZV retinitis is a potentially sight-threatening complication that occurs in both immunocompetent and immunocompromised persons. Current knowledge regarding pathogenesis and antiviral therapy is reviewed.

Multifocal vasculopathy due to Varicella-Zoster Virus (VZV): serial analysis of VZV DNA and intrathecal synthesis of VZV antibody in cerebrospinal fluid

Recognition of multifocal vasculopathy due to varicella-zoster virus (VZV) is often problematic. We describe a human immunodeficiency virus-infected patient who had progressive central nervous system disease for >3 months. Both VZV DNA and antibody were detected in cerebrospinal fluid (CSF) specimens; serial polymerase chain reaction analyses confirmed the diagnosis and guided the duration of therapy. Reduced ratios of VZV antibody in serum to that in CSF were also demonstrated.

Use of PCR for the diagnosis of herpesvirus infections of the central nervous system

Polymerase chain reaction (PCR) analysis of cerebrospinal fluid (CSF) has revolutionized the diagnosis of nervous system viral infections, particularly those caused by human herpesviruses (HHV). The PCR technique allows the detection of minute quantities of DNA or RNA in body fluids and tissues. Both fresh-frozen and formalin-fixed tissues may be utilized for PCR assays, with the latter making archival studies possible. CSF PCR has now replaced brain biopsy as the gold standard for the diagnosis of herpes simplex virus (HSV) encephalitis. PCR analysis of both CSF and nervous system tissues has also broadened our understanding of the spectrum of disease caused by HSV-1 and -2, cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella zoster virus (VZV) and HHV-6. PCR results obtained from tissue specimens must be interpreted cautiously, since this highly sensitive technique may detect portions of viral genomic material that may be present even in the absence of active viral infection. Tissue PCR results in particular must be corroborated with clinical and neuropathologic evidence of central nervous system (CNS) infection. In several neurological diseases, negative PCR results have provided evidence against a role for herpesviruses as the causative agents. This review summarizes the role of CSF PCR in the diagnosis and therapeutic management of herpesvirus infections of the nervous system, particularly those caused by HSV and VZV.

Multifocal chorioretinal atrophy associated with herpes zoster ophthalmicus

A 73-year-old woman developed multiple depigmented lesions in the fundus 4-6 months after an episode of acute Herpes zoster ophthalmicus. Post-mortem examination of the globe 15 years after this acute episode confirmed multiple old chorioretinal scars probably due to vasculitis of the short posterior ciliary arteries and branches. Patchy old infarcts were also noted in the iris.

Polymerase chain reaction as a diagnostic adjunct in herpesvirus infections of the nervous system

Polymerase chain reaction (PCR) is a powerful technique that allows detection of minute quantities of DNA or RNA in cerebrospinal fluid (CSF), vesicle and endoneurial fluids, blood, fresh-frozen, and even formalin-fixed tissues. Various infectious agents can be detected with high specificity and sensitivity, including bacteria, parasites, rickettsia and viruses. PCR analysis of CSF has revolutionized the diagnosis of nervous system viral infections, particularly those caused by human herpesviruses (HHV), and has now replaced brain biopsy as the gold standard for diagnosis of herpes simplex virus (HSV) encephalitis. PCR analysis of both CSF and nervous system tissues has also broadened our understanding of the spectrum of disease caused by HSV-1 and -2, cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella zoster virus (VZV), and HHV-6. Nonetheless, positive tissue PCR results must be interpreted cautiously, especially in cases that lack corroborating clinical and neuropathologic evidence of infection. Moreover, positive PCR results from tissues do not distinguish latent from productive (lytic) viral infections. In several neurological diseases, negative PCR results have provided strong evidence against a role for herpesviruses as the causative agents. This review focuses on the use of PCR tests to diagnose HSV and VZV infections of the nervous system.

Varicella-Zoster virus infections of the nervous system: clinical and pathologic correlates

BACKGROUND

Diseases that present with protean manifestations are the diseases most likely to pose diagnostic challenges for both clinicians and pathologists. Among the most diverse disorders caused by a single known toxic, metabolic, neoplastic, or infectious agent are the central and peripheral nervous system complications of varicella-zoster virus (VZV).

METHODS

The pathologic correlates of the neurologic complications of VZV infection, as well as current methods for detecting viral infections, are discussed and presented in pictorial format for the practicing pathologist.

RESULTS

Varicella-zoster virus causes chickenpox (varicella), usually in childhood; most children manifest only mild neurologic sequelae. After chickenpox resolves, the virus becomes latent in neurons of cranial and spinal ganglia of nearly all individuals. In elderly and immunocompromised individuals, the virus may reactivate to produce shingles (zoster). After zoster resolves, many elderly patients experience postherpetic neuralgia. Uncommonly, VZV can spread to large cerebral arteries to cause a spectrum of large-vessel vascular damage, ranging from vasculopathy to vasculitis, with stroke. In immunocompromised individuals, especially those with cancer or acquired immunodeficiency syndrome, deeper tissue penetration of the virus may occur (as compared with immunocompetent individuals), with resultant myelitis, small-vessel vasculopathy, ventriculitis, and meningoencephalitis. Detection of the virus in neurons, oligodendrocytes, meningeal cells, ependymal cells, or the blood vessel wall often requires a combination of morphologic, immunohistochemical, in situ hybridization, and polymerase chain reaction (PCR) methods. The PCR analysis of cerebrospinal fluid remains the mainstay for diagnosing the neurologic complications of VZV during life.

CONCLUSIONS

Varicella-zoster virus infects a wide variety of cell types in the central and peripheral nervous system, explaining the diversity of clinical disorders associated with the virus.

Chickenpox and stroke in childhood: a study of frequency and causation

BACKGROUND AND PURPOSE

The purpose of this study was to determine whether infection with varicella is causal for arterial ischemic stroke (AIS) in children.

METHODS

First, a prospective cohort study was conducted in young children (aged 6 months to 10 years) with AIS at 2 institutions (cohort study). The presence of varicella infection <12 months before AIS was determined and compared with the published frequency of varicella infection in the healthy pediatric population. The clinical and radiographic features of AIS were compared between the varicella and nonvaricella study cohorts. Second, a literature search of varicella-associated AIS was conducted, and the clinical and radiographic features were compared with the study nonvaricella cohort.

RESULTS

In the cohort study, 22 (31%) of 70 consecutive children with AIS had a varicella infection in the preceding year compared with 9% in the healthy population. Children in the varicella cohort were more likely to have basal ganglia infarcts (P<0.001), abnormal cerebral vascular imaging (P<0.05), and recurrent AIS or transient ischemic attacks (P<0.05) than those in the nonvaricella cohort. The pooled literature analysis of 51 cases of varicella-associated AIS showed similar findings to the varicella cohort.

CONCLUSION

In young children with AIS, there is a 3-fold increase in preceding varicella infection compared with published population rates, and varicella-associated AIS accounts for nearly one third of childhood AIS. Varicella-associated AIS has characteristic features, including a 2-fold increase in recurrent AIS and transient ischemic attacks. Varicella is an important risk factor for childhood AIS.