Pre-eruptive varicella cerebellitis confirmed by PCR

Subclinical immune reactions to viral infections may correlate with child and adolescent diagnosis of attention-deficit/hyperactivity disorder: a preliminary study from Turkey

BACKGROUND

Attention-Deficit/Hyperactivity Disorder (ADHD) is one of the most common neuro-developmental disorders of childhood and adolescence. Studies focusing on the relationship of infectious agents and ADHD are scarce. It is also known that cerebellar injury may lead to hyperactive behavior. This study aimed to evaluate the relationship between viral agents of cerebellitis and the diagnosis of ADHD.

METHODS

The study group was formed of 60 consecutive ADHD patients and 30 healthy children. IgG levels for VZV; HSV-1, CMV, Measles, Mumps, Rubella and EBV were evaluated.

RESULTS

Males were significantly higher among patients with ADHD (65% vs. 40%, p=0.025). Patients with ADHD displayed significantly higher positivity for measles IgG (80% vs. 60%, p=0.044). When patients with ADHD were classified according to their pubertal status, adolescents with ADHD displayed higher positivity for mumps (100% vs. 74.4%, p=0.043). Most of the patients were diagnosed with ADHD-Combined or Hyperactive/Impulsive Subtypes (56.6%) while 43.3% were diagnosed with ADHD-predominantly inattentive type. When patients with subtypes of ADHD were compared in terms of seropositivity, it was found that patients with ADHD-Combined/ Hyperactive-Impulsive subtypes had significantly elevated reactions for Rubella (100% vs. 88.5%, p=0.044).

CONCLUSION

Although limited to a single center and may be prone to sampling biases, our results may support the notion that immune reactions may be related with ADHD among children and adolescents. Further, prospective studies from multiple centers are needed to support our findings and establish causality.

Varicella encephalitis and pneumonia in a patient with end stage renal failure

We describe a patient with end stage renal failure (ESRF) on hemodialysis who was admitted to our department for primary varicella infection complicated by varicella pneumonia and encephalitis. Varicella infections results in serious morbidity and mortality in ESRF dialysis and transplant patients. Evidence published thus far suggests that live attenuated varicella vaccines are effective and safe in ESRF and renal transplant patients. Worldwide a few countries have instituted guidelines for the varicella immunisation in ESRF patients. However, in the Asia Pacific Region, it has not been widely given due to the lack of national consensus guidelines. Our case depicts that primary varicella infection can occur at any time in immunosupressed patients and thus suffer serious consequences from it. With increasing burden of chronic kidney disease, Renal Physicians and Family Physicians in the Asia Pacific Region should meet and study the epidemiological data in each individual country and decide on the consensus guidelines on how the varicella vaccination can be targeted for those at risk.

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.

Neurological disease produced by varicella zoster virus reactivation without rash

Reactivation of varicella zoster virus (VZV) from latently infected human ganglia usually produces herpes zoster (shingles), characterized by dermatomal distribution pain and rash. Zoster is often followed by chronic pain (postherpetic neuralgia or PHN) as well as meningitis or meningoencephalitis, cerebellitis, isolated cranial nerve palsies that produce ophthalmoplegia or the Ramsay Hunt syndrome, multiple cranial nerve palsies (polyneuritis cranialis), vasculopathy, myelopathy, and various inflammatory disorders of the eye. Importantly, VZV reactivation can produce chronic radicular pain without rash (zoster sine herpete), as well as all the neurological disorders listed above without rash. The protean neurological and ocular disorders produced by VZV in the absence of rash are a challenge to the practicing clinician. The presentation of these conditions varies from acute to subacute to chronic. Virological confirmation requires the demonstration of amplifiable VZV DNA in cerebrospinal fluid (CSF) or in blood mononuclear cells, or the presence of anti-VZV IgG antibody in CSF or of anti-VZV IgM antibody in CSF or serum.

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 infection: clinical features, molecular pathogenesis of disease, and latency

Varicella zoster virus (VZV) is an exclusively human neurotropic alphaherpesvirus. Primary infection causes varicella (chickenpox), after which virus becomes 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 elderly and immunocompromised individuals, VZV reactivates and causes a wide range of neurologic disease. This article discusses the clinical manifestations, treatment, and prevention of VZV infection and reactivation; pathogenesis of VZV infection; and current research focusing on VZV latency, reactivation, and animal models.

[Postvaricella cerebellar ataxia in children in Costa Rica]

INTRODUCTION

Postvaricella cerebellar ataxia (PVCA) and meningoencephalitis are the most common acute neurological complications of chickenpox. The objective of this study was to describe the clinical presentation, management, and outcome of children hospitalized with PVCA in the only pediatric hospital of this developing country, where routine varicella immunization is not yet available.

METHODS

We performed a retrospective chart review of children aged 1-12 years old admitted to the National Children's Hospital of Costa Rica from January 1997 to June 2004 with a diagnosis of PVCA.

RESULTS

Among the 441 immunocompetent patients admitted for varicella zoster virus-associated complications during this period, 37 (8.4%) had PVCA. Twenty-four of the 37 (64.9%) patients were boys. The mean (range) age was 5 (1-10) years. The median (range) interval from rash onset to admission was 2 (1-3) days. Cerebrospinal fluid analysis was available in 22 (59.5%) patients and was normal in all. Head computed tomography showed cerebral edema in six out of 18 patients (33.3%). Intravenous acyclovir was administered to 23 patients but no significant differences in clinical manifestations or outcomes were observed in treated versus untreated patients. The mean (range) length of ataxia was 4 (1-10) days, and seven (19%) patients were still ataxic on discharge. The mean (range) length of hospital stay was 4.4 (2-11) days. Minor sequelae were documented in 13 out of 24 (54.2%) patients during follow-up visits and telephone contacts.

CONCLUSIONS

PVCA is usually associated with a favorable prognosis; however, neurological sequelae can occur. The real utility of acyclovir treatment and brain imaging studies in these children remains controversial.

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.

Ataxias

Gait disorders in elderly individuals are a major cause of falls and their attendant morbidities. Ataxia is one of the neurologic components of fall risk, as are inattention or confusion, visual impairment, vestibular impairment, subcortical white matter disease, parkinsonism, weakness, sensory loss, orthostasis or arrhythmia with alterations in blood pressure, pain, medication use, and environmental hazards. Ataxia in the geriatric population has many causes. Correctly identifying them can improve clinicians' ability to offer treatment and management strategies to patients and their families. The goals should be safe mobility and preserved activities of daily living.

Polymerase chain reaction analysis and oligoclonal antibody in the cerebrospinal fluid from 34 patients with varicella-zoster virus infection of the nervous system

OBJECTIVE

To study cerebrospinal fluid (CSF) and serum samples from 34 consecutive patients suspected of having varicella-zoster virus (VZV) infection of the central nervous system (CNS).

POPULATION AND METHODS

The patients were divided into three groups. The first group consisted of 27 patients with a rash in one to three dermatomes and clinical suspicion of meningitis and radiculitis; among them, three subgroups were distinguished according to the affected dermatome: ophthalmicus (n = 9), oticus (n = 11) and cervico-thoraco-lumbar zoster (n = 7). Four cases of zoster sine herpete (ZSH) were included in the second group: these patients presented with either radiculitis (n = 2) or meningoencephalitis (n = 2), without cutaneous eruption. The third group consisted of three patients with a generalised rash and encephalitis. A polymerase chain reaction (PCR) for VZV DNA and antigen-driven immunoblots for oligoclonal anti-VZV antibodies were carried out on all CSF samples.

RESULTS

PCR of the CSF was positive in 44% of the patients from the first group, mainly within the first 7 days after eruption. In addition, intrathecal synthesis of anti-VZV antibodies was detected in 37% of patients, always after an interval of 7 days (p<0.0001). Among the four patients with ZSH, a positive VZV PCR was detected in three patients and CSF-specific oligoclonal anti-VZV antibodies in two. PCR was also positive in the CSF of two of the three patients with generalised rash and encephalitis; local production of anti-VZV antibodies was seen in a second CSF sample in one patient, and was also present in the third patient.

CONCLUSION

Amplification of VZV DNA by PCR in the CSF and antigen-driven immunoblots have important diagnostic value in suspected VZV infection, although their presence depends on the timing of the CSF sampling. VZV is thought to be a causative agent in unexplained cases of meningitis associated with radiculitis or focal CNS symptoms, even in the absence of skin manifestations. In such patients, rapid diagnosis by this combined approach permits early antiviral treatment.

Clinical relevance of polymerase chain reaction (PCR) assays and antigen-driven immunoblots for the diagnosis of neurological infectious diseases

Polymerase chain reaction assays are a powerful tool for detecting the presence of infectious genomes in the cerebrospinal fluid. Positive results always mean a current or pending infection of the central nervous system. Subacute (>7 days) or chronic infections induce an intrathecal humoral immune response and the appearance of oligoclonal IgG antibodies directed against the causal infectious agent. This local synthesis may be observed even in cases of severe systemic immunodeficiency. The use of polymerase chain reactions in combination with the detection of a specific intrathecal immune response should represent the most reliable strategy for the diagnosis of viral and chronic infections of the central nervous system. The authors describe their experience, using this approach, in herpetic encephalitis, acute and recurrent herpetic meningitis, varicella zoster-induced neurological diseases, cytomegalovirus encephalitis, progressive multifocal leukoencephalitis and tuberculous meningitis.

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.

Molecular Techniques in the Diagnosis of Central Nervous System Infections

Development of polymerase chain reaction (PCR)-based molecular techniques has initiated a revolution in the field of diagnostic microbiology. These techniques have not only provided rapid, noninvasive detection of microorganisms that cause central nervous system (CNS) infections, but have also demonstrated that several neurologic disorders are linked to infectious agents. While PCR-based techniques are predicted to be widely used in diagnosing and monitoring CNS infections, the limitations, as well as strengths, of these techniques must be clearly understood by both clinicians and laboratory personnel to ensure proper utilization.

Acute cerebellitis

Many recent reports of acute cerebellitis with a critical or potentially critical course have changed the conception of the disease from an acute cerebellar ataxia with a benign course to a notable disease entity with a heterogeneous pathogenesis. The most characteristic finding by magnetic resonance imaging is diffuse cortical swelling of the cerebellum, often complicated by hydrocephalus or tonsillar herniation. A timely assessment and appropriate choice of treatment, including surgical intervention when indicated, are key to improving the outcome of affected patients.

Sudden death from fulminant acute cerebellitis

Acute cerebellitis is postulated to result from viral and/or autoimmune etiologies. This disease has been reported to have a variable course. We report a case of sudden death from acute fulminant cerebellitis in a 13-year-old ballet dancer. Serial CT and MRI demonstrated rapid progression of the disease. Histopathologic correlation is provided. The etiologies, clinical course, therapeutic interventions and postmortem evaluation of this potentially life-threatening condition are briefly reviewed.

Acute childhood hemiplegia associated with chickenpox

Although primary varicella-associated central nervous system complications and herpes zoster ophthalmicus with delayed hemiplegia are well known, and chickenpox is a common infection, cerebral vasculopathy associated with chickenpox has only been described recently. We report the case of an 18-month-old girl who developed a right hemiplegia 10 days after the onset of a primary varicella infection. She has the shortest latent interval in the literature. Cranial computed tomography and magnetic resonance imaging suggest an infarction involving the left putamen and internal capsule. Magnetic resonance angiography is normal. Possible causes of acute infantile hemiplegia are excluded. Neurologic signs gradually improve without any specific treatment. A review of the literature is also presented.

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.

Pre-eruptive neurologic manifestations associated with multiple cerebral infarcts in varicella

A boy, 4 years, 9 months of age, presented with acute hemiplegia, lethargy, ataxia, and dysarthria 24 hours prior to the eruption of typical varicella exanthem. Magnetic resonance imaging findings were typical of multiple cerebral ischemic infarcts. It is suggested that during the period of secondary viremia varicella zoster virus invaded the cerebral blood vessels causing vasculopathy and cerebrovascular infarcts.