CNS Diseases Associated with Varicella Zoster Virus and Herpes Simplex Virus Infection: Pathogenesis and Current Therapy

Cerebral venous sinus thrombosis as a complication of primary varicella infection in a child, case report

INTRODUCTION AND IMPORTANCE

Chickenpox (Varicella) is a benign illness caused by varicella-zoster virus, predominant in childhood.Chicken pox related neurological complications are seen in less than 1% cases of chickenpox.Cerebral Venous thrombosis due to primary (VZV) infection is very rare, and it may occurs secondary to primary or re-activation the virus.

CASE PRESENTATION

We report a case of 5-year-old female complained of ataxia, vomiting, headache, and drowsiness 7 days after the onset varicella zoster infection. She had vesicular lesions with scab over the trunk and limbs.

CLINICAL DISCUSSION

Neurological examination revealed left hemiparesis.Her blood counts and metabolic parameters were normal.Computed tomography brain showed hemorrhagic infarct in the left temporo-parietal region. Coagulation profile was normal. Magnetic resonance imaging (MRI) brain revealed hemorrhagic infarct in the same region. Magnetic resonance Venogram showed thrombosis of left transverse sinus and sigmoid sinus and internal jugular vein.VZV- IgG antibody was positive but CSF VZV PCR (Polymerase chain reaction) was found to be negative.Intravenous acyclovir for 15 days, and low-molecular-weight heparin for 3 days overlapped with oral Warfarin for 3months,. After 3 months follow up, the patient experienced a complete recovery. MRI repeated after 3 months showed recanalization of the sinuses.

CONCLUSION

The pathogenic link of occurrence of CSVT after VZV infection is unclear, but some articles showed that it is related to direct endothelial damage by the virus.Early recognition of this complication of VZV infection and prompt treatment is essential to prevent catastrophic complications.

Neurological Disorders Associated with Human Alphaherpesviruses

Herpes simplex virus (HSV) encephalitis is the most common cause of sporadic fatal encephalitis worldwide, and central nervous system (CNS) involvement is observed in approximately one-third of neonatal HSV infections . In recent years, single-gene inborn errors of innate immunity have been shown to be associated with susceptibility to HSV encephalitis . Temporal lobe abnormalities revealed by magnetic resonance imaging-the most sensitive imaging method for HSV encephalitis-are considered strong evidence for the disease. Detection of HSV DNA in the cerebrospinal fluid by polymerase chain reaction (PCR) is the gold standard for the diagnosis of HSV encephalitis and neonatal meningoencephalitis. Intravenous acyclovir for 14-21 days is the standard treatment in HSV encephalitis. Neurological outcomes in neonates are improved by intravenous high-dose acyclovir for 21 days followed by oral acyclovir suppressive therapy for 6 months. Varicella-zoster virus (VZV) causes a wide range of CNS manifestations. VZV encephalitis typically occurs after primary infection, and reactivation of VZV may cause encephalitis. On the other hand, VZV infection of cerebral arteries produces vasculopathy, which can manifest as ischemic stroke. Vasculopathy can occur after primary infection or reactivation of VZV. PCR detection of VZV DNA in the cerebrospinal fluid can be used for the diagnosis of encephalitis or vasculopathy. Although there are no controlled treatment trials to assess VZV treatments of encephalitis or vasculopathy, intravenous acyclovir is a common treatment.

Management of suspected viral encephalitis in children - Association of British Neurologists and British Paediatric Allergy, Immunology and Infection Group national guidelines

In the 1980s the outcome of patients with herpes simplex encephalitis was shown to be dramatically improved with aciclovir treatment. Delays in starting treatment, particularly beyond 48 h after hospital admission, are associated with a worse prognosis. Several comprehensive reviews of the investigation and management of encephalitis have been published. However, their impact on day-to-day clinical practice appears to be limited. The emergency management of meningitis in children and adults was revolutionised by the introduction of a simple algorithm as part of management guidelines. In February 2008 a group of clinicians met in Liverpool to begin the development process for clinical care guidelines based around a similar simple algorithm, supported by an evidence base, whose implementation is hoped would improve the management of patients with suspected encephalitis.

MR imaging of neonatal brain infections

Infections of the brain in the postnatal period differ from those in older children as a result of a combination of distinct epidemiologic factors in general, and immaturity of neonatal brain and immunologic host response in particular. It has been recognized that clinical and neurologic signs are often nonspecific, sometimes scarce, and seldom correlate with the extent of neuroimaging findings, thus warranting an early MR imaging examination in the course of the disease, enabling rapid therapy institution and better clinical outcome. This article reviews most of postnatal pathogen agents involved in neonatal brain infections, related physiopathology, and neuroimaging findings.

Neonatal brain infections

Infections of the brain in the neonatal period differ considerably from infections in the older child, due to a variety of age-specific factors that are related not only to the child, but also to the mother, and to specific pathogenic organisms. It has been recognized that clinical and neurological signs are often non-specific, sometimes scarce, and seldom correlate with the extent of neuroimaging findings, thus warranting early imaging to ensure timely therapy and improved outcome.

Environmental triggers of multiple sclerosis

Multiple sclerosis is a chronic immune-mediated disease of the central nervous system that develops in young adults with a complex genetic predisposition. Similar to other autoimmune disease, HLA-DR and -DQ alleles within the HLA class II region on chromosome 6p21 are by far the strongest risk-conferring genes. Less robust susceptibility effects have been reported for non-MHC related genetic variants. Improvements in the design of epidemiological studies helped to identify consistent environmental risk-associations such as the increased susceptibility for MS in individuals with a history of infectious mononucleosis, a symptomatic primary infection with the human γ-herpesvirus Epstein-Barr virus (EBV). Sun exposure and serum vitamin D levels are emerging non-infectious environmental risk factors that may have independent roles. The analysis of environmental effects will likely expand in the next few years and will allow for the generation of testable hypotheses as to how environmental insults interact with genetic factors to jointly determine the susceptibility to MS. Insights gained from these studies might facilitate the development of prevention strategies and more effective treatments for MS.

A successfully treated case of herpes simplex encephalitis complicated by subarachnoid bleeding: a case report

Introduction

Histopathologically, herpes simplex virus type 1 causes hemorrhagic necrosis. Overt hemorrhage is infrequent in herpes simplex virus encephalitis but can lead to poor outcomes. This report describes a successfully treated case of herpes simplex virus encephalitis associated with subarachnoid bleeding in which real-time polymerase chain reaction was useful for diagnosis.

Case presentation

A 30-year-old previously healthy Japanese woman who had fever and headache for five days presented with disorganised speech, unusual behavior and delusional thinking. Real-time polymerase chain reaction amplification of herpes simplex virus type 1 in cerebrospinal fluid was positive (38,000 copies/mL) and antivirus treatment was started. During the course of her illness, the level of her consciousness decreased in association with desaturation and tachycardia. Thrombosis of the right pulmonary artery trunk with pulmonary embolism was evident on enhanced chest computed tomography. In addition, cranial computed tomography revealed subarachnoid and intraventricular bleeding. Intravenous heparin (12,000 U/day) was started and the dose was adjusted according to the activated partial thromboplastin time for about a month (maximum dose of heparin, 20,400 U/day). After the treatments, her Glasgow coma score increased and the thrombosis of the pulmonary artery trunk had disappeared.

Conclusions

The present case raises the question of whether anticoagulant treatment is safe in patients with herpes simplex virus encephalitis complicated by subarachnoid bleeding.

Viral triggers of multiple sclerosis

Genetic and environmental factors jointly determine the susceptibility to develop Multiple Sclerosis (MS). Collaborative efforts during the past years achieved substantial progress in defining the genetic architecture, underlying susceptibility to MS. Similar to other autoimmune diseases, HLA-DR and HLA-DQ alleles within the HLA class II region on chromosome 6p21 are the highest-risk-conferring genes. Less-robust susceptibility effects have been identified for MHC class I alleles and for non-MHC regions. The role of environmental risk factors and their interaction with genetic susceptibility alleles are much less well defined, despite the fact that infections have long been associated with MS development. Current data suggest that infectious triggers are most likely ubiquitous, i.e., highly prevalent in the general population, and that they require a permissive genetic trait which predisposes for MS development. In this review article, we illustrate mechanisms of infection-induced immunopathologies in experimental animal models of autoimmune CNS inflammation, discuss challenges for the translation of these experimental data into human immunology research, and provide future perspectives on how novel model systems could be utilized to better define the role of viral pathogens in MS.

Isolated cerebellar ataxia: an early neurological complication of enteric fever

Enteric fever is associated with a variety of clinical presentations and complications. Although central nervous system involvement is not uncommon in enteric fever, acute cerebellar ataxia as a presenting feature is rare. A 7-year-old boy with enteric fever who presented with acute cerebellar ataxia is reported.

Central nervous system infections of herpesvirus family

Herpesviruses are one of the most common groups of pathogens causing central nervous system infections in humans. They mostly cause encephalitis, meningitis, or myelitis in immunocompetent and immunocompromised patients. Children, adults, and the elderly can all be affected. Although contrast-enhanced CT is more widely used for diagnosis, contrast-enhanced MR imaging combined with diffusion-weighted imaging is superior to CT in the detection of early changes and the real extent of the disease, and in assessing prognosis and monitoring response to antiviral treatment. More sophisticated techniques, such as MR spectroscopy and perfusion imaging, can aid in the differential diagnosis of herpesvirus infections from other tumoral, demyelinating, and ischemic processes.

Neuroimaging of herpesvirus infections in children

Six members of the herpesvirus family cause well-described neurologic disease in children: herpes simplex virus-1 (HSV-1), herpes simplex virus-2 (HSV-2), varicella-zoster (VZV), Epstein-Barr (EBV), cytomegalovirus (CMV), and human herpes virus-6 (HHV-6). When herpesviruses infect the central nervous system (CNS), the clinical presentation is non-specific and often confounding. The clinical urgency is often underscored by progressive neurologic deficits, seizures, or even death, and prompt diagnosis and treatment rely heavily on neuroimaging. This review focuses on the spectrum of cerebral manifestations caused by these viruses, particularly on non-congenital presentations. Recent advances in our understanding of these viruses are discussed, including new polymerase chain reaction techniques that allow parallel detection, which has improved our recognition that the herpesviruses are neurotropic and involve the CNS more often than previously thought. Evolving knowledge has also better elucidated viral neuropathology, particularly the role of VZV vasculitis in the brain, HHV-6 in febrile seizures, and herpesvirus reactivation in immunosuppressed patients. The virology, clinical course, and CNS manifestations of each virus are reviewed, followed by descriptions of neuroimaging findings when these agents infect the brain. Characteristic but often subtle imaging findings are discussed, as well as technical pearls covering appropriate use of MRI and MRI adjuncts to help differentiate viral infection from mimics.

Acute childhood hemiplegia associated with chickenpox and elevated anticardiolipin antibody

Chickenpox is a common infection of childhood. Central nervous system complications, such as cerebellar ataxia and meningoencephalitis, are estimated to occur in less than 1% of cases of chickenpox. Although transverse myelitis and hemiplegia have also, although rarely, been reported, hemiplegia associated with chickenpox and elevated anticardiolipin antibody has not been reported in the literature. We report the case of a 2.5-year-old boy who developed a right hemiplegia 3 weeks after the onset of a primary varicella infection. The serum level of anticardiolipin antibody IgG was markedly elevated. Brain magnetic resonance imaging (MRI) revealed an infarction involving the left globus pallidus, caudate nucleus, and posterior leg of the internal capsule. Laboratory studies ruled out all known causes of stroke. Neurologic signs and symptoms slowly improved with supportive treatment. Varicella infection should be considered one of the possible causes of acute ischemic strokes in children. Usually, two or more risk factors are detected in children with ischemic strokes, and we suggest that all possible causes of strokes be investigated in children with ischemic strokes.

Herpes simplex encephalitis: adolescents and adults

Herpes simplex encephalitis (HSE) remains one of the most devastating infections of the central nervous system despite available antiviral therapy. Children and adolescents account for approximately one third of all cases of HSE. Clinical diagnosis is suggested in the encephalopathic, febrile patient with focal neurologic signs. However, these clinical findings are not pathognomonic because numerous other diseases in the central nervous system can mimic HSE. Neurodiagnostic evaluation can provide support for the diagnosis by the demonstration of temporal lobe edema/hemorrhage by magnetic resonance image scan and spike and slow-wave activity on electroencephalogram. In the current era, the diagnostic gold standard is the detection of herpes simplex virus (HSV) DNA in the cerebrospinal fluid by polymerase chain reaction (PCR). Although PCR is an excellent test and preferable to brain biopsy, false negatives can occur early after disease onset. Acyclovir is the treatment of choice and is administered at 10 mg/kg every 8 h for 21 days. Even with early administration of therapy after the disease onset, nearly two thirds of survivors have significant residual neurologic deficits. Current investigative efforts are assessing the prognostic value of quantitative PCR detection of viral DNA at the onset of therapy as well as at the completion of therapy and the contribution of prolonged antiviral therapy to improved neurologic 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.

Post-varicella intracranial haemorrhage in a child

We report a case of a 7-month-old male with primary intracranial haemorrhage 2 months after infection with varicella zoster virus (VZV). His initial clinical course was complicated by seizures and right hemiparesis; when last seen at 22 months the only positive finding was of left hand preference. Although the literature has recently established the association of arterial ischaemic stroke and VZV infection, primary intracranial haemorrhage has been reported only in one case. The child reported here had anterior interhemispheric haemorrhage due to a focal arteritis of the left anterior cerebral artery. The vascular abnormality was transient and had radiological features compatible with either a focal arteritis or vasospasm as a direct result of blood surrounding the vessels. We postulate that direct invasion of VZV caused extensive inflammation of the vessel wall and aggressive tissue penetration resulting in necrotizing angiitis and intracranial haemorrhage. We suggest that VZV infection should be considered a potential risk factor for intracranial haemorrhage in children.

Herpes simplex encephalitis. Is anticoagulation safe?

BACKGROUND

Herpes simplex encephalitis (HSE) still carries a high morbidity and mortality.

REVIEW SUMMARY

The authors report a 27-year-old patient who presented with an HSE manifested by a high temperature, seizures, and headaches. His hospitalization course was complicated by a pulmonary embolism. After anticoagulation was started, the patient developed a right temporal hematoma at the same region of the abnormal signal on magnetic resonance imaging. The patient underwent a craniotomy and evacuation of the hematoma with an uneventful postoperative outcome.

CONCLUSION

The safety of anticoagulation in HSE has not been raised in the literature previously, and it needs further study.

Herpes simplex: Encephalitis children and adolescents

Herpes simplex encephalitis (HSE) remains one of the most devastating infections of the central nervous system despite available antiviral therapy. Children and adolescents account for approximately one third of all cases of HSE. Clinical diagnosis is suggested in the encephalopathic, febrile patient with focal neurologic signs. However, these clinical findings are not pathognomonic because numerous other infections in the central nervous system can mimic HSE. Support for the diagnosis from a neurodiagnostic perspective is aided by the demonstration of disease of the temporal lobe by magnetic resonance image scan and spike and slow-wave activity on electroencephalogram. In the current era, the gold standard for establishing diagnosis is the detection of herpes simplex virus DNA in the cerebrospinal fluid by polymerase chain reaction (PCR). Although PCR is an excellent test and far more desirable than brain biopsy, false negatives can occur early after disease onset. Current therapeutic management calls for the administration of acyclovir at 10 mg/kg every 8 hours for 21 days. Even with early administration of therapy after the onset of disease, nearly two thirds of survivors will have significant residual neurologic deficits. Recent investigative efforts are assessing the value of PCR detection of viral DNA at the completion of therapy and the value of prolonged antiviral therapy.

Quantitative real time PCR detection of Varicella-zoster virus DNA in cerebrospinal fluid in patients with neurological disease

Varicella-zoster virus (VZV) reactivation can lead to the development of neurological disease. Diagnosis has been based on the detection of VZV DNA in cerebrospinal fluid (CSF) by PCR-based methods. The aim of this study was to determine whether the VZV DNA copy number in the CSF correlates with the course of the disease and to determine its prognostic relevance. VZV DNA was quantified in CSF samples obtained from 30 patients with neurological disease due to VZV reactivation using real time PCR, and the VZV DNA copy number was correlated to the clinical and laboratory findings for each case. Viral loads ranged from 50 copies/ml to 2.6 x 10(8) copies/ml. Significantly higher viral loads [geometric mean (GM): 7.2 x 10(4) copies/ml] were found in patients with encephalitis compared to patients with meningitis (GM: 4.1 x 10(3) copies/ml) (P=0.01, Mann-Whitney U test). In eight patients without zoster dermal lesions no significant difference in viral load (GM: 4.6 x 10(3)) was detected compared to patients exhibiting dermal lesions (GM: 2.2 x 10(4)) (P=0.14). High copy numbers of VZV DNA in CSF were clearly associated with the severity of neurological disease and none of the patients with a VZV viral load below 10(4) copies had a disease course which required intensive care.

Intracranial hemorrhage in herpes simplex encephalitis: an unusual presentation

We describe a 14-month-old patient with atypical presentation of herpes simplex encephalitis. She initially presented with fever, lethargy, seizures, and large hemorrhages in the right parietal lobe, and clinical findings suggestive of a hypercoagulable state. The etiology of coagulation abnormality was not identified, although it was suggested as a possible causative factor in severe bleeding along with acute neuronal lysis as a result of infection. Although large intracerebral hemorrhages are occasionally described with systemic herpes infection, this presentation is unusual beyond the infant period.

Clinical manifestations of varicella-zoster virus infection

Infections by VZV, the virus that causes chickenpox and herpes zoster, usually are diagnosed by the classic clinical presentations. In immunocompromised patients, however, the atypical presentation can make the diagnosis more challenging. Although varicella typically follows an uncomplicated course in children, adults and immunocompromised patients can develop complications involving several organs; some complications may be fatal. Prevention of disease with the vaccine is ideal. When varicella or zoster infection does occur, proper treatment should be initiated, depending on the age and immune status of the patient.

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.

Viral infections after renal transplantation

Viral infections are a leading cause of posttransplantation morbidity and mortality. A number of recent developments have altered our understanding and management of these disorders. The pathogenetic roles of several viruses, including human herpesviruses 6 and 8, have been newly established. Molecular-based diagnostic tests now make more rapid diagnosis possible. The licensing of new potent antiviral agents offers a wider choice of drugs for viral prophylaxis and treatment. The use of more potent immunosuppressive agents is responsible in part for the increasing incidence of some viral infections, but this varies among drugs, and individual viruses differ in their sensitivity to immunosuppressive agents. This review summarizes the natural history, diagnosis, prevention, and treatment of many common viral infections after renal transplantation.

The Immunization Monitoring Program Active (IMPACT) prospective five year study of Canadian children hospitalized for chickenpox or an associated complication

BACKGROUND

Varicella vaccine was approved for use in Canada in 1998. A major goal of universal varicella vaccine programs is to reduce severe infection and associated complications. Baseline data are essential against which to judge the effectiveness of routine childhood immunization.

OBJECTIVE

To describe morbidity and mortality among children hospitalized for chickenpox. Methods. From January 1, 1991, to March 31, 1996, chickenpox admissions to 11 pediatric referral centers were actively identified. Patient and illness characteristics were compared for 3 subgroups defined by prior health: healthy; unhealthy but immunocompetent; immunocompromised.

RESULTS

Of 861 cases 488 (56.7%) were healthy, 75(8.7%) were unhealthy and 298 (34.6%) were immunocompromised. The immunocompromised children differed from healthy/unhealthy cases in mean age (6.4 vs. 4.0/4.6 years, respectively, P < 0.0001); median interval from rash onset to admission (2 vs. 5/5 days, P < 0.0001); complication rate (20% vs. 90%/79%; P = 0.001); and rate of acyclovir therapy (98% vs. 24%/39%; P = 0.001). Unhealthy vs. healthy cases had a higher frequency (P < 0.01) of intensive care (13.3% vs. 4.7%), ventilation (9.3% vs. 2.0%) and death (4% vs. 0.2%).

CONCLUSION

These data provide a baseline for morbidity/mortality resulting from chickenpox before varicella vaccine use in Canada.

Varicella vaccine

Varicella vaccine is safe, effective, and cost-effective in healthy children, adolescents, and adults. Breakthrough cases of MVLS are significantly milder than wild-type varicella infection. No severe adverse events have been reported following vaccination, and the incidence of herpes zoster is less in vaccinees than in individuals who have had natural varicella infections. To date, there is no evidence waning immunity following vaccination. "New and improved" varicella vaccines that may be more effective than the current vaccine and can be stored at refrigerator temperatures may soon become available in the United States.

Neuroimaging of postnatal pediatric central nervous system infections

Pediatric neuroimaging plays an important role in the timely diagnosis of postnatal central nervous system (CNS) infections, and in some patients the imaging findings are sufficiently specific to suggest a cause. The sequela of CNS infection, including hydrocephalus, subdural collections, ischemia/infarction, cerebral abscess, demyelination, and vascular thrombosis, can be accurately depicted and serially followed with current imaging techniques. The purpose of this review is to describe the spectrum of pediatric postnatal CNS infections, emphasizing key pathological and neuroimaging features, and to outline the strengths, weaknesses, and applications of current neuroimaging technology. The prenatal and perinatal infections falling under the designation of TORCH (toxoplasmosis, other [e.g., syphilis, HIV], rubella, cytomegalovirus, and herpes simplex II) are not covered.

Magnetic resonance angiography of primary varicella vasculitis: report of two cases

Two patients with onset of hemiparesis 3 weeks following primary varicella infection demonstrated contralateral temporal lobe and basal ganglia infarctions on magnetic resonance imaging. In both cases, magnetic resonance angiography (MRA) was performed and demonstrated flow abnormalities ipsilateral to the infarcts. Digital subtraction angiography was performed in one case; however, the findings were significantly less conspicuous than those of the MRA. MRA proved to be sensitive to the diagnosis of varicella-induced vasculitis in two consecutive cases and provided a noninvasive means of following the progression of the disease process in response to therapy.

Acute disseminated encephalomyelitis exacerbated by varicella

The actual incidence of central nervous system complications with varicella ranges from 0.1 to 0.7% in several series and the time interval between the rash and the type of neurological manifestation varies widely. Cerebellar ataxia and hypotonia are the most common neurological abnormalities associated with varicella. We present a report on a 6-year-old girl with an unusual course of disease finally presenting a probable diagnosis of acute disseminated encephalitis.

Disseminated cutaneous zoster and aseptic meningitis in a previously healthy patient

A previously healthy, 37-year-old immunocompetent man presented with disseminated cutaneous zoster and aseptic meningitis. Varicella zoster virus DNA was recovered from the cerebrospinal fluid (CSF) by the polymerase chain reaction. Cytological evaluation of the CSF revealed 'reactive, highly atypical lymphocytosis'. The patient fully recovered after treatment with aciclovir.

Luminometric microplate hybridization for detection of varicella-zoster virus PCR product from cerebrospinal fluid

We modified and optimized a new microplate hybridization assay to detect the varciella-zoster virus (VZV) PCR product, and studied cerebrospinal fluid (CSF) samples of 287 patients with meningitis, encephalitis or other neurological diseases or symptoms. Specific antibodies to VZV and reference antigens were determined by enzyme immunoassay from serum and CSF, they were then compared with clinical findings and with the results obtained by VZV-PCR using different detection methods for VZV-specific amplified DNA. VZV DNA was found in the CSF of 25 patients using the microplate hybridization assay and chemiluminescence detection for amplified DNA. All 25 CSF samples were also positive in Southern blotting. Among the patients, 10 had chickenpox, 4 had shingles, and 11 had no rash at all. The detection rate of VZV-specific DNA by microplate hybridization was 30% higher than that obtained by conventional agarose gel electrophoresis. In most patients the diagnosis was confirmed by demonstrating specific intrathecal antibody production to VZV but not to other viruses. These results indicate the presence of VZV in the central nervous system (CNS) in many patients with chickenpox or shingles, and even in patients without a rash. The microplate hybridization assay based on chemiluminescence detection improves considerably the detection rate of the VZV-PCR product compared to agarose gel electrophoresis and will add to the list of recognized VZV infections in the CNS. It is especially useful in cases where there is no cutaneous manifestation.

Varicella-zoster virus

Varicella-zoster virus (VZV) is a ubiquitous human alphaherpesvirus that causes varicella (chicken pox) and herpes zoster (shingles). Varicella is a common childhood illness, characterized by fever, viremia, and scattered vesicular lesions of the skin. As is characteristic of the alphaherpesviruses, VZV establishes latency in cells of the dorsal root ganglia. Herpes zoster, caused by VZV reactivation, is a localized, painful, vesicular rash involving one or adjacent dermatomes. The incidence of herpes zoster increases with age or immunosuppression. The VZV virion consists of a nucleocapsid surrounding a core that contains the linear, double-stranded DNA genome; a protein tegument separates the capsid from the lipid envelope, which incorporates the major viral glycoproteins. VZV is found in a worldwide geographic distribution but is more prevalent in temperate climates. Primary VZV infection elicits immunoglobulin G (IgG), IgM, and IgA antibodies, which bind to many classes of viral proteins. Virus-specific cellular immunity is critical for controlling viral replication in healthy and immunocompromised patients with primary or recurrent VZV infections. Rapid laboratory confirmation of the diagnosis of varicella or herpes zoster, which can be accomplished by detecting viral proteins or DNA, is important to determine the need for antiviral therapy. Acyclovir is licensed for treatment of varicella and herpes zoster, and acyclovir, valacyclovir, and famciclovir are approved for herpes zoster. Passive antibody prophylaxis with varicella-zoster immune globulin is indicated for susceptible high-risk patients exposed to varicella. A live attenuated varicella vaccine (Oka/Merck strain) is now recommended for routine childhood immunization.

MR and CT imaging patterns in post-varicella encephalitis

The aim of the investigation was to determine the patterns of cerebral involvement on computed tomography (CT) and magnetic resonance (MR) imaging in post-varicella encephalitis. Four children between the ages of 2 and 11 years presented over a 5-year period with a diagnosis of post-varicella encephalitis. Their imaging studies and clinical data were reviewed retrospectively. The medical histories of all four children were noncontributory except for recent bouts of chickenpox 1 week to 3 months prior to hospitalization. Three children presented with parkinsonian manifestations. Bilateral, symmetric hypodense, nonenhancing basal ganglia lesions were found on CT. These areas showed nonenhancing low signal intensity on T1-weighted images and high signal intensity on T2-weighted images on MR. One child presented with diffuse, multiple gray and white matter lesions of similar imaging characteristics; some lesions, however, did enhance. This child had no gait disturbances. Post-varicella encephalitis can produce two patterns of dramatic CT and MR findings. With an appropriate history and clinical findings, varicella as a cause of bilateral basal ganglia or diffuse cerebral lesions can be differentiated from other possible etiologies which include trauma, anoxia, metabolic disorders and demyelinating diseases.

Disseminated multifocal herpes zoster leukoencephalitis and subcortical hemorrhage in an immunosuppressed child

We describe a rare case of multifocal varicella-zoster leukoencephalitis in an immunosuppressed adolescent boy who developed a herpetiform rash on his groin and subsequently presented with a subacute encephalopathy, aphasia, and hemiparesis. Magnetic resonance imaging scan of the brain revealed multifocal bi-hemispheric target-like lesions predominantly in the white matter. A magnetic resonance imaging scan 2 weeks later showed a subcortical hemorrhage in the left insular region. He received long-term high-dose intravenous acyclovir and had significant improvement in his neurologic status.

Pre-eruptive varicella cerebellitis confirmed by PCR

The diagnosis of pre-eruptive varicella cerebellitis is usually based on a history of exposure and thus depends on a subjective clinical assessment. The confirmation of the diagnosis has traditionally depended on the development of skin manifestations of varicella and on varicella-zoster antibody seroconversion. Confirming the diagnosis of pre-eruptive cerebellar ataxia or encephalitis early in the course of a viral infection may save the patient unnecessary tests, procedures, or attempts at therapeutic intervention. A patient is reported in whom, after clinically suspecting a diagnosis of pre-eruptive varicella cerebellitis, the diagnosis was confirmed by performing polymerase chain reaction analysis of varicella-zoster virus DNA in peripheral blood leukocytes and cerebrospinal fluid. The patient developed skin manifestations of varicella 5 days after the onset of neurologic symptoms and 15 days after known exposure. In some patients with preeruptive varicella cerebellitis, polymerase chain reaction may be extremely useful for rapid confirmation of the diagnosis.

Encephalitis associated with herpes zoster: a case report and review

This paper describes the case of a patient with a history of affective disorder who developed encephalitis associated with herpes zoster which presented as a delirium with prominent manic symptoms. Published reports of encephalitis following herpes zoster infections are reviewed. The diagnosis of herpes zoster-associated encephalitis should be suspected in individuals with changes in his or her mental state, an abnormal electroencephalogram and an abnormal cerebrospinal fluid examination which closely follow a cutaneous herpes zoster lesion.

Pre-eruptive varicella encephalitis and cerebellar ataxia

Varicella-related neurologic symptoms usually appear during or following the exanthem. Pre-eruptive neurologic manifestations are extremely rare. We report a 6-year-old boy who developed encephalitis, characterized by drowsiness and left-sided hyperactive deep tendon reflexes and cerebellar ataxia, both of which antedated the exanthem by 16 days. The diagnostic and public health implications are discussed.

Intrathecal humoral immune reaction in zoster infections

Intrathecal humoral immune reaction in 26 patients with a reactivation of varicella-zoster virus was analyzed. 11 suffered from ganglionitis, in 7 cases an additional affection of the lower motor neuron was demonstrable. In 8 patients, meningitis, myelitis or cerebral infarctions by zoster angiitis were diagnosed. Intrathecal immune reaction in ganglionitis was weak whereas an intense IgG synthesis became demonstrable in all meningomyelitis/cerebral infarction cases. As demonstrated by immunoblotting, in early stages of the disease immune reaction in serum and cerebrospinal fluid differed only quantitatively. In the further course, most intrathecally synthesized antibodies were directed against low molecular antigens whereas serum pattern did not change. In some patients, additional antibodies not detectable in serum were demonstrable. Though intensity markedly differed, no qualitative differences between the immune response in ganglionitis and more widespread zoster infections of the CNS were detectable.

Herpes simplex virus type I infection of the CNS induces major histocompatibility complex antigen expression on rat microglia

Rats were infected with herpes simplex virus type I (HSV-1) by corneal scarification. The spread of virus in the brain, the infiltration of leucocytes into infected areas, and the expression of major histocompatibility complex (MHC) glycoproteins by brain cells were assessed as a function of time by immunohistochemistry. Virus moved along neuronal pathways, achieving widespread distribution in the brain by days 8-10 when the illness appeared most severe. Granulocytes, T-lymphocytes, and monocytes infiltrated the tissue matrix at sites of infection. Microglial cells were induced to express MHC class I and class II glycoproteins. Reactive microglia near the sites of infection most vigorously expressed such glycoproteins. At the peak of the infection they were detectable on microglia throughout the brain, including areas apparently separated from active infection. Evidence of viral antigens, as well as microglial MHC expression, had largely disappeared by day 30. Neurons, astrocytes, and oligodendroglial cells failed to express MHC antigens.

Varicella with delayed contralateral hemiparesis detected by MRI

We report a 3 1/2-year-old boy who developed a hemiparesis 4 weeks after the onset of a varicella infection. In previously described cases of varicella with delayed contralateral hemiparesis, computed tomography typically revealed infarcts in the basal ganglia and internal capsule. To our knowledge, our patient is the first studied by magnetic resonance imaging. The pathogenesis of this syndrome may be a varicella zoster virus-related vasculopathy similar to that observed in herpes zoster ophthalmicus with delayed contralateral hemiparesis.

Herpes zoster myelitis occurring during treatment for systemic lupus erythematosus

A 15-year-old girl with systemic lupus erythematosus suddenly developed fever, meningismus, and herpes zoster. Within 48 hours, transverse myelitis developed at the level of the nerve root involvement of the herpes zoster. Since both systemic lupus erythematosus and varicella-zoster have been reported to cause myelitis, therapy was initiated for both. The rapid and simultaneous resolution of both the herpes zoster and the neurologic deficits strongly supports the causal association of both with varicella-zoster. This is the second reported case of herpes zoster-associated transverse myelitis in a patient with systemic lupus erythematosus.