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

Herpes zoster encephalopathy or acyclovir neurotoxicity: a management dilemma

This is a case report of a 69-year-old morbidly obese woman who presented with mental status changes after she was treated with acyclovir for shingles. The predominant symptoms were word-finding difficulties and visual hallucinations. Complicating her presentation was acyclovir-induced acute renal injury causing her creatinine level to rise up to 7.4 mg/dL. Acyclovir was discontinued on the suspicion of acyclovir neurotoxicity. Even though PCR for varicella zoster virus in the cerebrospinal fluid was positive, acyclovir was not restarted and the patient continued to improve and returned to her baseline.

[Cerebral infarction and intracranial aneurysm related to the reactivation of varicella zoster virus in a Japanese acquired immunodeficiency syndrome (AIDS) patient]

A 35-years-old right-handed man admitted to our hospital with a worsening of dysarthria, left facial palsy and left hemiparesis for 2 days. Acquired immunodeficiency syndrome (AIDS) was diagnosed when he was 28 years old. At that time, he also was treated for syphilis. After highly active antiretroviral treatment (HAART) was introduced at the age of 35 years old, serum level of human immunodeficiency virus (HIV) was not detected, but the number of CD4+ T cells was still less than 200/μl. He had no risk factors of atherosclerosis including hypertension, diabetes and hyperlipidemia. He had neither coagulation abnormality nor autoimmune disease. Magnetic resonance imaging (MRI) showed acute ischemic infarction spreading from the right corona radiate to the right internal capsule without contrast enhancement. Stenosis and occlusion of intracranial arteries were not detected by MR angiography. Although argatroban and edaravone were administered, his neurological deficits were worsened to be difficult to walk independently. Cerebrospinal fluid (CSF) examination showed a mild mononuclear pleocytosis (16/μl).　Oligoclonal band was positive. The titer of anti-varicella zoster virus (VZV) IgG antibodies was increased, that indicated VZV reactivation in the central nervous system (CNS), although VZV DNA PCR was not detected. Therefore, acyclovir (750 mg/day for 2 weeks) and valaciclovir (3,000 mg/day for 1 month) were administered in addition to stroke therapy. He recovered to be able to walk independently 2 month after the admission.Angiography uncovered a saccular aneurysm of 3 mm at the end of branch artery of right anterior cerebral artery, Heubner artery, 28 days after the admission. We speculated that VZV vasculopathy caused by VZV reactivation in CNS was involved in the pathomechanism of cerebral infarction rather than HIV vasculopathy in the case.

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.

Pediatric arterial ischemic stroke

PURPOSE OF REVIEW

This article aims to provide a broad overview of pediatric arterial ischemic stroke, from recognition and diagnosis to the short-term and long-term management based on current available literature.

RECENT FINDINGS

Arterial ischemic stroke in children represents a significant disorder with a concerning high rate of adverse outcomes, including potentially preventable recurrent stroke. Although awareness of pediatric stroke is increasing, diagnosis is still commonly delayed or missed altogether, particularly in younger children. Current vascular imaging techniques have limitations in accurate diagnosis of arteriopathies that are now recognized as an important cause of childhood stroke. Significant variability exists in treatment of pediatric stroke. Management is based on published consensus guidelines; however, individual children require an individualized approach.

SUMMARY

As pediatric stroke specialists become increasingly available, the collaboration of such experts on individual management is crucial. Definitive evidence-based treatment for pediatric stroke awaits the development of randomized controlled trials.

Neurofilament heavy chain as a marker of neuroaxonal pathology and prognosis in acute encephalitis

BACKGROUND AND PURPOSE

The neurological outcome of acute encephalitis can be devastating and early prognosis remains difficult. Biomarkers that quantify the extent of early brain injury are needed to improve the prognostic accuracy and aid patient management. Our objective was to assess whether cerebrospinal fluid (CSF) protein biomarkers of neuroaxonal and glial cell injury are elevated in distinct forms of acute encephalitis and predictive of poor outcome.

METHODS

This was a prospective study of patients presenting with acute encephalitis to three teaching hospitals in London, UK. Levels of neurofilament heavy chain (NfH, SMI35) and S100B were quantified in CSF using enzyme-linked immunosorbent assay. The outcome was assessed by the Glasgow Outcome Scale (GOS).

RESULTS

Fifty-six patients with acute encephalitis were recruited and classified into the following diagnostic categories: infectious (n = 20), inflammatory (n = 14) and unknown etiology (n = 22). Pathological levels of NfH and S100B were observed in 24/56 (43%) and 54/56 (96%), respectively. Patients with infectious encephalitis had significantly higher NfH levels compared with the other two groups (P < 0.05). A poor outcome (GOS < 5) was associated with significantly higher CSF NfH levels within samples taken 2 weeks after symptom onset.

CONCLUSIONS

This study suggests that longitudinal CSF NfH levels are of superior prognostic value compared with CSF S100B levels. Prolonged release of NfH, a marker of neuroaxonal damage, was associated with poor outcome. Potentially there is a window of opportunity for future neuroprotective treatment strategies in encephalitis.

Reassessing the link between herpes zoster ophthalmicus and stroke

This editorial will assess a proposed link between herpes zoster ophthalmicus and subsequent stoke. Herpes zoster (also called shingles) is caused by varicella-zoster virus (VZV), one of the 9 human herpesviruses. When children contract their primary VZV infection, virus often travels to the trigeminal ganglia and establishes latency. Upon reactivation in late adulthood, the same virus travels anterograde to cause herpes zoster ophthalmicus. In some people, the virus also traffics from the same trigeminal ganglion along afferent fibers around the carotid artery and its branches. Subsequently VZV-induced inflammation within the affected cerebral arteries leads to occlusion and stroke. In one retrospective analysis of people with herpes zoster ophthalmicus, there was a 4.5 fold higher risk of stroke than in a control group. Two other studies found a less compelling association.

Focal encephalitis following varicella-zoster virus reactivation without rash in a healthy immunized young adult

Herein we describe an episode of focal varicella-zoster virus (VZV) encephalitis in a healthy young man with neither rash nor radicular pain. The symptoms began with headaches and seizures, after which magnetic resonance imaging detected a single hyperintense lesion in the left temporal lobe. Because of the provisional diagnosis of a brain tumor, the lesion was excised and submitted for pathological examination. No tumor was found. But the tissue immunostained positively for VZV antigens, and wild-type VZV sequences were detected. In short, this case represents VZV reactivation, most likely in the trigeminal ganglion, in the absence of clinical herpes zoster.

Primary angiitis of the central nervous system and reversible cerebral vasoconstriction syndrome

Primary angiitis of the central nervous system (PACNS) is one of the most devastating pathologic processes that affect the central nervous system (CNS). It results in exclusive inflammation and destruction of CNS blood vessels. Progressive debilitating unexplained neurological deficit associated with abnormal cerebrospinal fluid (CSF) analysis findings is the typical picture of the disease. CNS biopsy is the gold standard diagnostic test. Immunosuppressive therapy is the core treatment. Reversible cerebral vasoconstriction syndrome (RCVS) is a main mimic of PACNS. RCVS is characterized clinically by recurrent thunderclap headache with or without neurological deficit and normal CSF analysis findings and angiographically by reversible diffuse segmental vasospasm of intracranial vessels. A stepwise diagnostic approach should be followed to differentiate PACNS from RCVS and exclude the other clinical, radiographic, and angiographic mimics.

Herpes zoster as a risk factor for stroke and TIA: a retrospective cohort study in the UK

Objectives:

Stroke and TIA are recognized complications of acute herpes zoster (HZ). In this study, we evaluated HZ as a risk factor for cerebrovascular disease (stroke and TIA) and myocardial infarction (MI) in a UK population cohort.

Methods:

A retrospective cohort of 106,601 HZ cases and 213,202 controls matched for age, sex, and general practice was identified from the THIN (The Health Improvement Network) general practice database. Cox proportional hazard models were used to examine the risks of stroke, TIA, and MI in cases and controls, adjusted for vascular risk factors, including body mass index >30 kg/m², smoking, cholesterol >6.2 mmol/L, hypertension, diabetes, ischemic heart disease, atrial fibrillation, intermittent arterial claudication, carotid stenosis, and valvular heart disease, up to 24 years (median 6.3 years) after HZ occurrence.

Results:

Risk factors for vascular disease were significantly increased in cases of HZ compared with controls. Adjusted hazard ratios (AHRs) for TIA and MI but not stroke were increased in all patients with HZ (AHR [95% confidence interval]: 1.15 [1.09–1.21] and 1.10 [1.05–1.16], respectively). However, stroke, TIA, and MI were increased in cases whose HZ occurred when they were younger than 40 years (AHR [95% confidence interval]: 1.74 [1.13–2.66], 2.42 [1.34–4.36], 1.49 [1.04–2.15], respectively). Subjects younger than 40 years were significantly less likely to be asked about vascular risk factors than were older patients (p < 0.001).

Conclusion:

HZ is an independent risk factor for vascular disease in the UK population, particularly for stroke, TIA, and MI in subjects affected before the age of 40 years. In older subjects, better ascertainment of vascular risk factors and earlier intervention may explain the reduction in risk of stroke after the occurrence of HZ.

Nervous System Complications of Systemic Viral Infections

Invasion of the central nervous system (CNS) by viral agents typically produces a meningoencephalitis in which either meningitis or encephalitis may predominate. Viruses may also infect cranial or spinal blood vessels to produce ischemic injury. Viral and other infections may also elicit a host immune response which is cross-reactive with components of the neural tissue, resulting in encephalomyelitis, transverse myelitis, injury to peripheral nerves, or optic neuritis. This chapter discusses the pathogenesis of CNS viral infections and reviews clinical features of these disorders, major agents responsible in immunocompromised and immunocompetent individuals, and treatment. Prion diseases and postinfectious viral CNS syndromes including postinfectious encephalomyelitis, acute hemorrhagic leukoencephalitis, cerebellar ataxia, and transverse myelitis are also discussed.

Development, maintenance and disruption of the blood-brain barrier

The interface between the blood circulation and the neural tissue features unique characteristics that are encompassed by the term 'blood-brain barrier' (BBB). The main functions of this barrier, namely maintenance of brain homeostasis, regulation of influx and efflux transport, and protection from harm, are determined by its specialized multicellular structure. Every constituent cell type makes an indispensable contribution to the BBB's integrity. But if one member of the BBB fails, and as a result the barrier breaks down, there can be dramatic consequences and neuroinflammation and neurodegeneration can occur. In this Review, we highlight recently gained mechanistic insights into the development and maintenance of the BBB. We then discuss how BBB disruption can cause or contribute to neurological disease. Finally, we examine how this knowledge can be used to explore new possibilities for BBB repair.

Varicella zoster virus central nervous system immune reconstitution inflammatory syndrome presenting in a child

A HIV-positive child presented with acute onset of right hemiplegia, facial palsy and dysphasia 4 weeks after commencing highly active antiretroviral therapy. Magnetic resonance imaging confirmed a left-sided cerebral infarct. Cerebrospinal fluid polymerase chain reaction was positive for varicella zoster virus. This is the first reported pediatric case of varicella zoster virus-related immune reconstitution inflammatory syndrome involving the central nervous system.

Viral encephalitis in the ICU

Viral encephalitis causes an altered level of consciousness, which may be associated with fever, seizures, focal deficits, CSF pleocytosis, and abnormal neuroimaging. Potential pathogens include HSV, VZV, enterovirus, and in some regions, arboviruses. Autoimmune (eg, anti-NMDA receptor) and paraneoplastic encephalitis are responsible for some cases where no pathogen is identified. Indications for ICU admission include coma, status epilepticus and respiratory failure. Timely initiation of anti-viral therapy is crucial while relevant molecular and serological test results are being performed. Supportive care should be directed at the prevention and treatment of cerebral edema and other physiological derangements which may contribute to secondary neurological injury.

Chickenpox and risk of stroke: a self-controlled case series analysis

Children who experience chickenpox are at a 4-fold increased risk of ischemic stroke in the subsequent 6 months. The evidence is less strong for adults, possibly due to mechanistic differences in the role of inflammation in adult stroke risk.

Background. There is good evidence that respiratory and other infections that cause systemic inflammation can trigger strokes; however, the role of specific infections is unclear. Case reports have highlighted chickenpox as a possible risk factor for arterial ischemic stroke, particularly in children, but rigorous studies are needed to determine and quantify any increased risk.

Methods. We used anonymized electronic health records totaling >100 million person-years of observation from 4 UK primary care databases to identify individuals who had documented clinical chickenpox and a stroke or transient ischemic attack (TIA). Self-controlled case series methods were used to quantify any increased risk of first stroke or TIA in the 0–6 and 7–12 months following chickenpox compared to other observed time periods. We analyzed data within each database, and performed meta-analyses to obtain summary age-adjusted incidence ratios (IRs) separately for adults and children.

Results. Five hundred sixty eligible individuals (including 60 children) were identified who experienced chickenpox and a stroke or TIA during follow-up. Among children, there was a 4-fold increased risk of stroke in the 0–6 months after chickenpox (summary IR = 4.07; 95% confidence interval [CI], 1.96–8.45; I² = 0%). Among adults, there was a less marked increased risk with moderate between-database heterogeneity (random-effects summary IR = 2.13; 95% CI, 1.05–4.36; I² = 51%). There was no significant increased risk of stroke in the 7–12 months after chickenpox in children or adults, nor was there evidence of increased risk of TIA in either time period.

Conclusions. Our study provides new evidence that children who experience chickenpox are at increased risk of stroke in the subsequent 6 months.

Case definitions, diagnostic algorithms, and priorities in encephalitis: consensus statement of the international encephalitis consortium

BACKGROUND

Encephalitis continues to result in substantial morbidity and mortality worldwide. Advances in diagnosis and management have been limited, in part, by a lack of consensus on case definitions, standardized diagnostic approaches, and priorities for research.

METHODS

In March 2012, the International Encephalitis Consortium, a committee begun in 2010 with members worldwide, held a meeting in Atlanta to discuss recent advances in encephalitis and to set priorities for future study.

RESULTS

We present a consensus document that proposes a standardized case definition and diagnostic guidelines for evaluation of adults and children with suspected encephalitis. In addition, areas of research priority, including host genetics and selected emerging infections, are discussed.

CONCLUSIONS

We anticipate that this document, representing a synthesis of our discussions and supported by literature, will serve as a practical aid to clinicians evaluating patients with suspected encephalitis and will identify key areas and approaches to advance our knowledge of encephalitis.

Posterior reversible encephalopathy syndrome (PRES) in an HIV-1 infected patient with disseminated varicella zoster virus: a case report

Background

Posterior reversible encephalopathy syndrome (PRES) is an uncommon pathology characterized by the acute onset of headache, vomiting, altered consciousness, seizures and focal neurological deficits. It was initially described in the setting of hypertension, uremia and immunosuppression. In the last decade there have been emerging reports of PRES in patients with advanced human immunodeficiency virus (HIV)-infection in the presence of hypertension, dialysis, hypercalcaemia and two opportunistic infections: blastomycosis and tuberculosis (TB).

Case presentation

Here we present the case of a 54 year old male being treated for disseminated varicella zoster virus (VZV) and vasculopathy in the setting of HIV infection who acutely deteriorated to the point of requiring intubation. His clinicoradiological diagnosis was of PRES and he subsequently improved within 72 h with supportive management. Serial neuroimaging correlated with the clinical findings. The pathogenesis of PRES is poorly understood but is thought to stem from vasogenic oedema either as a result of loss of endothelial integrity and transudate of fluid across the blood–brain barrier, or secondary to vasospasm resulting in tissue oedema in the absence of infarction. How HIV infection impacts on this model is unclear. It is possible the HIV infection causes endothelial dysfunction and disruption of the blood–brain barrier that may be further exacerbated by infections in the central nervous system.

Conclusion

The phenomenon of PRES in advanced HIV is an important clinical entity for both physicians and critical care doctors to recognize firstly given its potential mortality but also because of its favourable prognosis and reversibility with supportive care and treatment of underlying causes.

Neurological complications of transplantation: part I: hematopoietic cell transplantation

Hematopoietic cell transplantation (HCT) is the preferred treatment for an expanding range of neoplastic and nonmalignant conditions. Increasing numbers of solid organ transplantations (SOTs) add an additional population of immunosuppressed patients with multiple potential neurological problems. While the spectrum of neurological complications varies with conditioning procedure and hematopoietic cell or solid organ source, major neurological complications occur with all transplantation procedures. This 2 part review emphasizes a practical consultative approach to central and peripheral nervous system problems related to HCT or SOT with clinical and neuroimaging examples from the authors' institutional experience with the following conditions: the diversity of manifestations of common infections such as varicella zoster virus, Aspergillus, and progressive multifocal leukoencephalopathy (PML), drug therapy-related complications, stroke mechanisms, the spectrum of graft versus host disease (GVHD), and neurologically important syndromes of immune reconstitution inflammatory syndrome (IRIS), posterior reversible encephalopathy syndrome (PRES), and posttransplantation lymphoproliferative disorder (PTLD). These complications preferentially occur at specific intervals after HCT and SOT, and neurological consultants must recognize an extensive spectrum of syndromes in order to effect timely diagnosis and expedite appropriate treatment.

Varicella zoster virus vasculopathy: clinical features and pathogenesis

Varicella zoster virus (VZV) vasculopathy is caused by productive virus infection of cerebral arteries, leading to inflammation, pathological vascular remodeling, and ischemic or hemorrhagic stroke. VZV vasculopathy occurs in immunocompetent and immunocompromised individuals and involves both large and small vessels. MRI abnormalities include more deep-seated than superficial lesions, particularly at gray-white matter junctions, and lesions may enhance. Diagnosis is challenging, since stroke can occur months after zoster rash and in the absence of rash or CSF pleocytosis. The best virological test for diagnosis is detection of anti-VZV IgG antibody in the CSF. Pathological studies of VZV-infected arteries from patients with VZV vasculopathy reveal that the arterial adventitia is the initial site of infection, after which virus spreads transmuraly towards the lumen. Histological and immunohistochemical studies of VZV-infected arteries show a thickened intima, disrupted internal elastic lamina, and loss of smooth muscle cells, that likely contribute to weakening of the vessel wall and occlusion. Early in disease, VZV-infected arteries contain CD4+ and CD8+ T cells, macrophages, and rare B cells, in addition to abundant neutrophils in early disease. Importantly, perivascular inflammatory cells underlie the areas of thickened intima, raising the possibility that soluble factors secreted by these cells contribute to arterial remodeling. This review discusses the clinical features of VZV vasculopathy and potential mechanisms of VZV-induced cerebrovascular remodeling and stroke.

Complications of varicella zoster virus reactivation

OPINION STATEMENT

Varicella zoster virus (VZV) is an exclusively human neurotropic alphaherpesvirus. Primary infection causes varicella (chickenpox), after which virus becomes latent in ganglionic neurons along the entire neuraxis. With advancing age or immunosuppression, cell-mediated immunity to VZV declines and virus reactivates to cause zoster (shingles), which can occur anywhere on the body. Skin lesions resolve within 1-2 weeks, while complete cessation of pain usually takes 4-6 weeks. Zoster can be followed by chronic pain (postherpetic neuralgia), cranial nerve palsies, zoster paresis, meningoencephalitis, cerebellitis, myelopathy, multiple ocular disorders and vasculopathy that can mimic giant cell arteritis. All of the neurological and ocular disorders listed above may also develop without rash. Diagnosis of VZV-induced neurological disease may require examination of cerebrospinal fluid (CSF), serum and/ or ocular fluids. In the absence of rash in a patient with neurological disease potentially due to VZV, CSF should be examined for VZV DNA by PCR and for anti-VZV IgG and IgM. Detection of VZV IgG antibody in CSF is superior to detection of VZV DNA in CSF to diagnose vasculopathy, recurrent myelopathy, and brainstem encephalitis. Oral antiviral drugs speed healing of rash and shorten acute pain. Immunocompromised patients require intravenous acyclovir. First-line treatments for post-herpetic neuralgia include tricyclic antidepressants, gabapentin, pregabalin, and topical lidocaine patches. VZV vasculopathy, meningoencephalitis, and myelitis are all treated with intravenous acyclovir.

Clinical practice: Herpes zoster

A 65-year-old man presents with a rash of 2 days duration over the right forehead with vesicles and pustules, a few lesions on the right side and tip of the nose, and slight blurring in the right eye. The rash was preceded by tingling in the area and is now associated with aching pain. How should this patient be evaluated and treated?

The short- and long-term risk of stroke after herpes zoster - a nationwide population-based cohort study

BACKGROUND AND OBJECTIVE

Varicella zoster virus (VZV) is known to cause VZV vasculopathy, which may be associated with stroke. A recent study found an increased risk of stroke within one year of herpes zoster. We aimed to investigate the short and long-term effects of herpes zoster on the risk of stroke.

METHODS

Using Danish national registers, we constructed a cohort consisting of all Danish adults ≥18 years old between 1995 and 2008 (n = 4.6 million; person-years of follow-up = 52.9 million). Individual-level information on prescriptions for herpes zoster antiviral treatment and diagnoses of stroke was obtained from national registers. We compared the risk of stroke in persons who had received the specific dosage of acyclovir for herpes zoster with persons who had never received antiviral treatment by Poisson regression.

RESULTS

During follow-up, 2.5% received treatment for herpes zoster and 5.0% were diagnosed with stroke. Individuals who had received medication had a 127% (95% CI 83-182%) increased risk the first two weeks, 17% (CI 9-24%) between two weeks and one year, and 5% (2-9%) after the first year. The increased risk was greatest in the youngest age group (<40). To control for healthcare-seeking behaviour, we conducted parallel analyses investigating the risk of selected fractures after herpes zoster and found no similar increased risks.

CONCLUSIONS

This large nationwide cohort study found an increased risk of stroke after treatment for herpes zoster. Although the short-term risk was particularly high, we cannot rule out the possibility of a small but important long-term risk.

[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.

Herpes zoster encephalitis presenting as multiple cerebral hemorrhages - a rare presentation: a case report

Introduction

An infection by herpes zoster virus is a common and important cause of encephalitis. Herpes zoster virus encephalitis if not treated promptly can result in significant morbidity and mortality. The diagnosis of herpes zoster virus encephalitis is based on clinical history, examination, neuroradiological imaging (magnetic resonance imaging and/or computed tomography scan), cerebrospinal fluid analysis and identification of the pathogen in cerebrospinal fluid by polymerase chain reaction amplification and/or anti-herpes zoster virus immunoglobulin G antibody in cerebrospinal fluid. Although ischemic intracerebral infarcts in patients with herpes zoster virus encephalitis or vasculopathy are reported in the literature, multiple intracerebral hemorrhages as a complication of herpes zoster virus encephalitis in an immunocompetent individual are extremely rare.

Case presentation

A 40-year-old Indian man presented with an acute history of four episodes of seizures, fever, headache, drowsiness, focal neurological deficits and vesicular eruptions over the abdomen in a typical dermatomal distribution. His head computed tomography scan revealed multiple cerebral hemorrhages. Investigations (positive ratio between the cerebrospinal fluid/serum quotients for anti-herpes zoster virus immunoglobulin G and total immunoglobulin G antibodies) established its infective origin due to herpes zoster virus. He developed bilateral pneumonia during the hospital course. He had an excellent recovery following a 2 weeks’ course of intravenous acyclovir.

Conclusion

Herpes zoster virus encephalitis or vasculopathy is a rare cause of multiple intracerebral hemorrhages and must be considered in the differential diagnosis of patients presenting with an acute history of fever, altered consciousness, and focal neurologic deficits with history of a typical herpetic rash. Its prompt recognition and treatment could alter the course of illness.

Encephalitis and postinfectious encephalitis

PURPOSE OF REVIEW

Encephalitis and postinfectious encephalitis represent two important conditions for the neurologist, both in terms of their presentations as neurologic emergencies and their potential to cause death or serious neurologic impairment. This article reviews the major infectious and noninfectious causes of encephalitis and discusses postinfectious encephalitis as an indirect effect of systemic illness.

RECENT FINDINGS

Encephalitis caused by herpes simplex virus type 1 and West Nile virus are of major importance. In addition, within the past few years we have gained improved understanding of the neurologic syndromes caused by varicella-zoster virus, the recognition of enterovirus 71 as a significant human pathogen, and the realization that encephalitis may also occur by autoimmune mechanisms requiring immunosuppressive therapy. We have also learned that postinfectious encephalitis may be recurrent rather than monophasic, and that children and adults initially diagnosed with postinfectious encephalitis may later develop classic multiple sclerosis.

SUMMARY

Encephalitis and postinfectious encephalitis present as neurologic emergencies requiring prompt diagnosis and initiation of treatment. Important concerns are to identify infectious conditions requiring antibiotic or antiviral therapy and postinfectious or other autoimmune encephalitides requiring immunosuppression.

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.

Varicella zoster virus infection presenting as isolated diplopia: a case report

BACKGROUND

Involvement of trochlear nerve during Varicella Zoster Virus (VZV) Infection has been rarely described, and always in association with skin rash.

CASE PRESENTATION

We describe the case of a patient with VZV infection presenting as isolated diplopia due to fourth cranial nerve palsy. The diagnosis has been obtained through the application of a standardized molecular diagnostic panel, and diplopia resolved after specific antiviral and corticosteroid therapy.

CONCLUSION

This case evidences that clinicians should be aware of atypical VZV infection, even in the absence of the typical skin rash.

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.

Acute viral infections of the central nervous system in immunocompetent adults: diagnosis and management

Patients with viral infections of the central nervous system (CNS) may present with a variety of neurological symptoms, most commonly dominated by either encephalitis or meningitis. The aetiological panorama varies in different parts of the world as well as over time. Thus, virological first-line diagnostics must be adapted to the current epidemiological situation and to the individual patient history, including recent travels. This review focuses on the diagnostics and treatment of viral CNS infections in the immunocompetent host from a Northern European perspective. Effective vaccines are available for viruses such as poliovirus and tick-borne encephalitis virus (TBEV) and for the childhood diseases morbilli (measles), rubella (German measles), parotitis (mumps) and varicella (chickenpox). However, cases do appear due to suboptimal immunization rates. In viral CNS infections, epidemiological surveillance is essential for establishing preventive strategies and for detecting emerging viruses. Knowledge of the possibilities and limitations of diagnostic methods for specific viral CNS infections is vital. A positive cerebral spinal fluid (CSF) polymerase chain reaction (PCR) finding is usually reliable for aetiological diagnosis. The demonstration of intrathecal antibody synthesis is useful for confirming the aetiology in a later stage of disease, hitherto sufficiently evaluated in herpes simplex encephalitis (HSE) and tick-borne encephalitis (TBE). Despite improved virological and differential diagnostic methods, aetiology remains unknown in about half of the cases with suspected viral encephalitis. Antiviral treatment is available chiefly for infections caused by herpesviruses, and acyclovir (aciclovir) is the drug of choice for empirical therapy in suspected viral encephalitis. However, randomized, controlled antiviral trials have only been conducted for HSE, while such studies are lacking in other viral CNS infections. Viral cytolysis and immune-mediated mechanisms may contribute to varying extents to neurological damage. Although the brain damage is believed to depend, to a varying degree, on the intrathecal host immune response, the use of corticosteroids in viral CNS infections is scarcely studied, as is specific treatment for neuroinflammation. Improved antiviral and immunomodulating treatment is desirable. Since neurological sequelae are still abundant, follow-up after severe viral CNS disease must include a neuropsychological assessment and an individually adapted rehabilitation plan.

HIV infection and stroke: current perspectives and future directions

HIV infection can result in stroke via several mechanisms, including opportunistic infection, vasculopathy, cardioembolism, and coagulopathy. However, the occurrence of stroke and HIV infection might often be coincidental. HIV-associated vasculopathy describes various cerebrovascular changes, including stenosis and aneurysm formation, vasculitis, and accelerated atherosclerosis, and might be caused directly or indirectly by HIV infection, although the mechanisms are controversial. HIV and associated infections contribute to chronic inflammation. Combination antiretroviral therapies (cART) are clearly beneficial, but can be atherogenic and could increase stroke risk. cART can prolong life, increasing the size of the ageing population at risk of stroke. Stroke management and prevention should include identification and treatment of the specific cause of stroke and stroke risk factors, and judicious adjustment of the cART regimen. Epidemiological, clinical, biological, and autopsy studies of risk, the pathogenesis of HIV-associated vasculopathy (particularly of arterial endothelial damage), the long-term effects of cART, and ideal stroke treatment in patients with HIV are needed, as are antiretrovirals that are without vascular risk.

Extensive extracranial and intracranial Varicella zoster vasculopathy

Varicella zoster virus (VZV)-induced vasculopathy is an uncommon cause of stroke in a young immunocompetent host. Owing to scarcity of data of VZV-induced vasculopathy and lack of awareness about this condition and its diagnostic test, these cases may be easily missed. In this case, we report an immunocompetent host presenting right-side hemiplegia with motor aphasia and complete loss of vision in the left eye due to complete occlusion of the left common carotid artery without any history of skin rash preceding stroke. Cerebrospinal fluid analysis for varicella antibody revealed very high titres and CT aortogram demonstrated aortoarteritis with occlusion of left common carotid artery. To our knowledge, varicella zoster vasculopathy-associated aortoarteritis has not been described in the literature.

Herpesvirus infections of the central nervous system in immunocompromised patients

Human herpesviruses may cause infections of the central nervous system during primary infection or following reactivation from a latent state. Especially in immunosuppressed patients the infection can take a life-threatening course, and therefore early diagnosis of herpesvirus-associated neurological diseases should have high priority. Clinical presentation in these patients is usually without typical features, making diagnosis even more challenging. Therefore general broad testing for different herpesviruses in cerebrospinal fluid samples is highly recommended. In addition, determination of the virus DNA level in the cerebrospinal fluid by quantitative assays seems to be of high importance to determine prognosis. Moreover, it might help to differentiate between specific virus-associated disease and unspecific presence of virus in the cerebrospinal fluid, especially in immunocompromised patients. Polymerase chain reaction analysis of cerebrospinal fluid has revolutionized the diagnosis of nervous system viral infections, particularly those caused by human herpesviruses. This review summarizes the role human herpesviruses play in central nervous system infections in immunocompromised patients, with a focus on the clinical manifestation of encephalitis.

Varicella zoster central nervous system vasculitis after allogeneic hematopoietic stem cell transplant successfully treated with cyclophosphamide

We report the first case of varicella zoster central nervous system vasculitis, to our knowledge, which responded to intravenous pulses of cyclophosphamide in an immunocompromised child with severe and progressive disease, without sequelae.

An update on diagnostic imaging studies for viral encephalitis

Viral encephalitis is still a life-threatening disease occurring at any age. It is critical to make a rapid and correct diagnosis for a better outcome of the disease. Accumulating evidence has suggested that MRI is a powerful tool for the detection of any lesion of the CNS caused by viral infections and helps to initiate the timely treatment. In this review, we summarize the current understanding of MRI findings of viral encephalitis, especially related to HSV, HIV, varicella zoster, Japanese encephalitis, John Cunningham, and influenza viruses. With these considerations, we learnt that the inclusion of diffusion-weighted image sequences on routine MRI examination would have a significant value in detecting the pathologic changes that occur following viral invasion of the CNS.

Neurovirulence of varicella and the live attenuated varicella vaccine virus

Varicella-zoster virus (VZV) is a neurotropic herpesvirus, which can cause a variety of complications during varicella infections. These range from meningoencephalitis to polyneuritis to retinitis. After primary VZV infection, VZV enters the dorsal root ganglia in a latent state. Reactivation from latency leads to zoster. The velocity of VZV is 13 cm per day, as the virus travels from ganglion to skin. The live attenuated varicella vaccine virus is markedly less neurovirulent than the wild-type virus. Nevertheless, a few cases of herpes zoster due to the vaccine virus have been documented. Usually, herpes zoster occurs in the same arm as the vaccination, often 3 or more years after vaccination. Thus, herpes zoster in a vaccinee often represents a reactivation of vaccine virus that was carried to the cervical dorsal root ganglia from a site of local replication in the arm. Finally, the role of autophagy during VZV infection is discussed. Autophagosome formation is a prominent feature in the skin vesicles during both varicella and herpes zoster. Therefore, autophagy is one of the innate immune mechanisms associated with VZV infection in humans.