Herpes simplex replication and dissemination is not increased by corticosteroid treatment in a rat model of focal Herpes encephalitis

The immunobiology of herpes simplex virus encephalitis and post-viral autoimmunity

Herpes simplex virus encephalitis (HSE) is the leading cause of non-epidemic encephalitis in the developed world and, despite antiviral therapy, mortality and morbidity is high. The emergence of post-HSE autoimmune encephalitis reveals a new immunological paradigm in autoantibody-mediated disease. A reductionist evaluation of the immunobiological mechanisms in HSE is crucial to dissect the origins of post-viral autoimmunity and supply rational approaches to the selection of immunotherapeutics. Herein, we review the latest evidence behind the phenotypic progression and underlying immunobiology of HSE including the cytokine/chemokine environment, the role of pathogen-recognition receptors, T- and B-cell immunity and relevant inborn errors of immunity. Second, we provide a contemporary review of published patients with post-HSE autoimmune encephalitis from a combined cohort of 110 patients. Third, we integrate novel mechanisms of autoimmunization in deep cervical lymph nodes to explore hypotheses around post-HSE autoimmune encephalitis and challenge these against mechanisms of molecular mimicry and others. Finally, we explore translational concepts where neuroglial surface autoantibodies have been observed with other neuroinfectious diseases and those that generate brain damage including traumatic brain injury, ischaemic stroke and neurodegenerative disease. Overall, the clinical and immunological landscape of HSE is an important and evolving field, from which precision immunotherapeutics could soon emerge.

Steroids for the treatment of viral encephalitis: a systematic literature review and meta-analysis

BACKGROUND

Specific antiviral treatment is only available for a small subset of viral encephalitis (VE). Adjunctive steroids are used, but there is scant evidence evaluating its utility. We present a systematic review and meta-analysis on the outcome of steroid use in VE.

METHODS

We conducted a systematic literature review and reported it according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards. Two observational studies from unpublished or partially published data were added. For the meta-analysis, we employed the metaphor package of the statistical software R-4.3.1.

RESULTS

We screened 378 studies and included 50. 155 patients were added from the Houston and Linz cohorts. Individual data were available for 281 persons, 120 (43%) of whom received steroids. The most common pathogens were herpes simplex virus 1, West Nile virus, and measles. Study designs and patient outcomes were heterogeneous. Only three of the trials report an advantage of steroid therapy. Steroid-induced side effects were scarce. Ten cohorts were included into the meta-analysis. For the pooled data, the null hypothesis could not be rejected (p = 0.245) using a random effects model, i.e., a benefit of steroid treatment on survival in VE could not be shown.

CONCLUSIONS

Steroids as potent anti-inflammatory agents may act through a reduction of secondary inflammation-mediated damage. Our data do not support the use of steroids in VE. However, multiple shortcomings apply. Standardized controlled trials are needed to investigate optimal dosing and timing of steroid administration and to explore potential subgroups that could benefit.

When herpes simplex virus encephalitis meets antiviral innate immunity

Herpes simplex virus (HSV) is the most common pathogen of infectious encephalitis, accounting for nearly half of the confirmed cases of encephalitis. Its clinical symptoms are often atypical. HSV PCR in cerebrospinal fluid is helpful for diagnosis, and the prognosis is usually satisfactory after regular antiviral treatment. Interestingly, some patients with recurrent encephalitis have little antiviral effect. HSV PCR in cerebrospinal fluid is negative, but glucocorticoid has a significant effect after treatment. Specific antibodies, such as the NMDA receptor antibody, the GABA receptor antibody, and even some unknown antibodies, can be isolated from cerebrospinal fluid, proving that the immune system contributes to recurrent encephalitis, but the specific mechanism is still unclear. Based on recent studies, we attempt to summarize the relationship between herpes simplex encephalitis and innate immunity, providing more clues for researchers to explore this field further.

Herpes Simplex Virus Meningoencephalitis Following Pulse-Dose Methylprednisolone: A Case Report and Literature Review

Patient: Male, 76-year-old

Final Diagnosis: Herpes simplex virus type 1 (HSV-1) encephalitis

Symptoms: Encephalopathy

Medication: —

Clinical Procedure: Lumbar puncture

Specialty: Critical Care Medicine

Untreated herpes simplex virus encephalitis without a fatal outcome

Herpes simplex virus encephalitis (HSE) is the most common sporadic fatal encephalitis. Although timely administered acyclovir treatment decreases mortality, neuropsychiatric sequelae is still common among survivors. Magnetic resonance imaging is frequently utilized for the diagnosis of HSE, which typically involves temporal lobe(s) and can be mixed with brain tumors involving the same area. Here, we report a case of HSE, who received acyclovir with a delay of 90 days because of presumptive tumor diagnosis and survived with minimal sequelae.

Cerebrospinal fluid biomarkers of brain injury, inflammation and synaptic autoimmunity predict long-term neurocognitive outcome in herpes simplex encephalitis

OBJECTIVES

The aim was to investigate the correlation between biomarkers of brain injury and long-term neurocognitive outcome, and the interplay with intrathecal inflammation and neuronal autoimmunity, in patients with herpes simplex encephalitis (HSE).

METHODS

A total of 53 adult/adolescent HSE patients were included from a prospective cohort in a randomized placebo-controlled trial investigating the effect of a 3-month follow-up treatment with valaciclovir. Study subjects underwent repeated serum/cerebrospinal fluid (CSF) sampling and brain magnetic resonance imaging in the first 3 months along with cognitive assessment using the Mattis Dementia Rating Scale (MDRS) at 24 months. CSF samples were analysed for biomarkers of brain injury, inflammation and synaptic autoimmunity. The predefined primary analysis was the correlation between peak CSF neurofilament protein (NFL), a biomarker of neuronal damage, and MDRS at 24 months.

RESULTS

Impaired cognitive performance significantly correlated with NFL levels (rho = -0.36, p = 0.020). Development of IgG anti-N-methyl-D-aspartate receptor (NDMAR) antibodies was associated with a broad and prolonged proinflammatory CSF response. In a linear regression model, lower MDRS at 24 months was associated with previous development of IgG anti-N-methyl-D-aspartate receptor (NMDAR) (beta = -0.6249, p = 0.024) and age (z-score beta = -0.2784, p = 0.024), but not CSF NFL, which however significantly correlated with subsequent NMDAR autoimmunization (p = 0.006).

DISCUSSION

Our findings show that NFL levels are predictive of long-term neurocognitive outcome in HSE, and suggest a causative chain of events where brain tissue damage increases the risk of NMDAR autoimmunisation and subsequent prolongation of CSF inflammation. The data provides guidance for a future intervention study of immunosuppressive therapy administered in the recovery phase of HSE.

Post-infectious neurological disorders

A multitude of environmental factors can result in breakdown of immune tolerance in susceptible hosts. Infectious pathogens are among the most important environmental triggers in the pathogenesis of autoimmunity. Certain autoimmune disorders have a strong association with specific infections. Several neurological autoimmune disorders are thought to occur through post-infectious mechanisms. In this review, we discuss the proposed mechanisms underlying pathogen-induced autoimmunity, and highlight the clinical presentation and treatment of several post-infectious autoimmune neurological disorders. We also highlight post-infectious neurological disorders in the setting of recent outbreaks.

Immunomodulatory Strategies in Herpes Simplex Virus Encephalitis

Herpes simplex virus 1 (HSV-1) can be responsible for life-threatening HSV encephalitis (HSE). The mortality rate of patients with HSE who do not receive antiviral treatment is 70%, with most survivors suffering from permanent neurological sequelae. The use of intravenous acyclovir together with improved diagnostic technologies such as PCR and magnetic resonance imaging has resulted in a reduction in the mortality rate to close to 20%. However, 70% of surviving patients still do not recover complete neurological functions. Thus, there is an urgent need to develop more effective treatments for a better clinical outcome. It is well recognized that cerebral damage resulting from HSE is caused by viral replication together with an overzealous inflammatory response. Both of these processes constitute potential targets for the development of innovative therapies against HSE. In this review, we discuss recent progress in therapy that may be used to ameliorate the outcome of patients with HSE, with a particular emphasis on immunomodulatory agents. Ideally, the administration of adjunctive immunomodulatory drugs should be initiated during the rise of the inflammatory response, and its duration should be limited in time to reduce undesired effects. This critical time frame should be optimized by the identification of reliable biomarkers of inflammation.

The German trial on Aciclovir and Corticosteroids in Herpes-simplex-virus-Encephalitis (GACHE): a multicenter, randomized, double-blind, placebo-controlled trial

Introduction

Comprehensive treatment of Herpes-simplex-virus-encephalitis (HSVE) remains a major clinical challenge. The current therapy gold standard is aciclovir, a drug that inhibits viral replication. Despite antiviral treatment, mortality remains around 20% and a majority of survivors suffer from severe disability. Experimental research and recent retrospective clinical observations suggest a favourable therapy response to adjuvant dexamethasone. Currently there is no randomized clinical trial evidence, however, to support the routine use of adjuvant corticosteroid treatment in HSVE.

Methods

The German trial of Aciclovir and Corticosteroids in Herpes-simplex-virus-Encephalitis (GACHE) studied the effect of adjuvant dexamethasone versus placebo on top of standard aciclovir treatment in adult patients aged 18 up to 85 years with proven HSVE in German academic centers of Neurology in a randomized and double blind fashion. The trial was open from November 2007 to December 2012. The initially planned sample size was 372 patients with the option to increase to up to 450 patients after the second interim analysis. The primary endpoint was a binary functional outcome after 6 months assessed using the modified Rankin scale (mRS 0-2 vs. 3-6). Secondary endpoints included mortality after 6 and 12 months, functional outcome after 6 months measured with the Glasgow outcome scale (GOS), functional outcome after 12 months measured with mRS and GOS, quality of life as measured with the EuroQol 5D instrument after 6 and 12 months, neuropsychological testing after 6 months, cranial magnetic resonance imaging findings after 6 months, seizures up to day of discharge or at the latest at day 30, and after 6 and 12 months.

Results

The trial was stopped prematurely for slow recruitment after 41 patients had been randomized, 21 of them treated with dexamethasone and 20 with placebo. No difference was observed in the primary endpoint. In the full analysis set (n = 19 in each group), 12 patients in each treatment arm achieved a mRS of 0-2. Similarly, we did not observe significant differences in the secondary endpoints (GOS, mRS, quality of life, neuropsychological testing).

Conclusion

GACHE being prematurely terminated demonstrated challenges encountered performing randomized, placebo-controlled trials in rare life threatening neurological diseases. Based upon our trial results the use of adjuvant steroids in addition to antiviral treatment remains experimental and is at the decision of the individual treating physician. Unfortunately, the small number of study participants does not allow firm conclusions.

Trial registration

EudraCT-Nr. 2005-003201-81.

Use of Topical Steroids in Conjunctivitis: A Review of the Evidence

PURPOSE

Conjunctivitis, or inflammation of the conjunctiva, is a common condition that can be caused by infectious (eg, bacterial or viral infections) and noninfectious (eg, allergy) etiologies. Treatment involves diagnosis of the underlying cause and use of appropriate therapies. A broad-spectrum therapy that can address multiple etiologies, and also the accompanying inflammation, would be very useful. In this review, we discuss the usefulness of topical ophthalmic corticosteroids and ophthalmic formulations that combine corticosteroids with anti-infectives/antibiotics for treating acute infectious conjunctivitis.

METHODS

A review of the published literature and relevant treatment guidelines.

RESULTS

Topical corticosteroids are useful in treating ocular inflammation, but most treatment guidelines recommend steroid use generally in severe cases of conjunctivitis. This is partly due to risks associated with steroid use. These risks include potential for prolonging adenoviral infections and potentiating/worsening herpes simplex virus infections, increased intraocular pressure, glaucoma, and cataracts. Most of these perceived risks are not, however, supported by high-quality clinical data. They are also associated with long-term steroid uses that are dissimilar to applications for infectious conjunctivitis. Clinical data show that ophthalmic formulations that combine corticosteroids with broad-spectrum anti-infectives could be effective and well tolerated when used for short-term treatment (≤2 weeks).

CONCLUSIONS

Corticosteroids, in combination with anti-infectives, could be a promising treatment option for acute conjunctivitis subject to development of further evidence on their effectiveness and safety in conjunctivitis treatment.

Multimodal management of severe herpes simplex virus encephalitis: A case report and literature review

BACKGROUND

Herpes simplex encephalitis (HSE) is the most frequent sporadic encephalitis in the world. In severe cases of HSE, the pathology usually progresses with an increase in intracranial pressure secondary to cerebral edema and/or hemorrhagic necrosis. Currently no high-power studies exist regarding the management of severe HSE and most of the papers reported in the literature are case reports. Decompressive craniectomy, effective in some cases of pharmaco-resistant intracranial hypertension (ICH) resulting from other causes, may be suggested in severe HSE, with several good results reported in the literature.

CASE DESCRIPTION

The case of a 26-year-old man with severe HSE and a subsequent ICH is reported. In dealing with an ICH rebellious to conservative treatment, it was decided to perform a right decompressive hemicraniectomy, associated with a right temporal polectomy. The postoperative evolution was satisfactory, with normal neuropsychological tests and a Glasgow Outcome Scale of 1.

CONCLUSION

Although herpes simplex encephalitis is sometimes devastatingly complicated by intracranial hypertension, its management lacks consensus and reliable data in the literature remains scarce. Surgical as well as conservative treatment, used together in a multimodal approach, may hold the key to a greater control of intracranial pressure, thus resulting in a better outcome. In this multimodal management, the window of opportunity where surgery may be considered is small, and must be discussed further and more precisely in future articles.

Brain microvascular endothelial-astrocyte cell responses following Japanese encephalitis virus infection in an in vitro human blood-brain barrier model

Japanese encephalitis virus (JEV) remains a leading cause of encephalitis, globally, which continues to grow in importance despite the availability of vaccines. Viral entry into the brain can occur via the blood-brain barrier (BBB), and inflammation at the BBB is a common final pathway in many brain infections. However, the role of the BBB during JEV infection and the contribution of the endothelial and astrocytic cell inflammation in facilitating virus entry into the brain are incompletely understood. We established a BBB model using human brain endothelial cells (HBECs) and human astrocytes. HBECs are polarised, and therefore the model was inoculated by JEV from the apical side to simulate the in vivo situation. The effects of JEV on the BBB permeability and release of inflammatory mediators from both apical and basolateral sides, representing the blood and the brain side respectively were investigated. JEV infected HBECs with limited active virus production, before crossing the BBB and infecting astrocytes. Control of JEV production by HBECs was associated with a significant increase in permeability, and with elevation of many host mediators, including cytokines, chemokines, cellular adhesion molecules, and matrix metalloproteases. When compared to the controls, significantly higher amounts of mediators were released from the apical side as opposed to the basolateral side. The increased release of mediators over time also correlated with increased BBB permeability. Treatment with dexamethasone led to a significant reduction in the release of interleukin 6 (IL6), C-C motif chemokine ligand 5 (CCL5) and C-X-C motif chemokine ligand 10 (CXCL10) from the apical side with a reduction in BBB disruption and no change in JEV production. The results are consistent with the hypothesis that JEV infection of the BBB triggers the production of a range of host mediators from both endothelial cells and astrocytes, which control JEV production but disrupt BBB integrity thus allowing virus entry into the brain. Dexamethasone treatment controlled the host response and limited BBB disruption in the model without increasing JEV production, supporting a re-investigation of its use therapeutically.

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Japanese encephalitis virus (JEV) infects human brain endothelial cells (HBECs).

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This triggers the production of a range of host mediators from both HBECs and astrocytes.

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JEV infection adversely affects blood-brain barrier (BBB) integrity.

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Dexamethasone treatment following JEV infection reduces the inflammation.

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Dexamethasone restores BBB integrity without increasing the levels of JEV particles.

Acute encephalitis - diagnosis and management

Encephalitis, inflammation of the brain, is most commonly caused by a viral infection (especially herpes simplex virus [HSV] type 1 in the UK) although autoimmune causes, such as N-methyl D-aspartate receptor (NMDAR) antibody encephalitis, are increasingly recognised. Most patients present with a change in consciousness level and may have fever, seizures, movement disorder or focal neurological deficits. Diagnosis hinges crucially on lumbar puncture and cerebrospinal fluid (CSF) examination, but imaging and electroencephalography (EEG) may also be helpful. Treatment of HSV encephalitis with aciclovir dramatically improves outcome, but the optimal management of autoimmune encephalitis is still uncertain. Many patients with encephalitis are left with residual physical or neuropsychological deficits which require long-term multidisciplinary management. Here we review assessment of patients with suspected encephalitis, general aspects of management and areas of ongoing research.

Intravenous immunoglobulin for the treatment of childhood encephalitis

BACKGROUND

Encephalitis is a syndrome of neurological dysfunction due to inflammation of the brain parenchyma, caused by an infection or an exaggerated host immune response, or both. Attenuation of brain inflammation through modulation of the immune response could improve patient outcomes. Biological agents such as immunoglobulin that have both anti-inflammatory and immunomodulatory properties may therefore be useful as adjunctive therapies for people with encephalitis.

OBJECTIVES

To assess the efficacy and safety of intravenous immunoglobulin (IVIG) as add-on treatment for children with encephalitis.

SEARCH METHODS

The Cochrane Multiple Sclerosis and Rare Diseases of the CNS group's Information Specialist searched the following databases up to 30 September 2016: CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov, and the WHO ICTRP Search Portal. In addition, two review authors searched Science Citation Index Expanded (SCI-EXPANDED) & Conference Proceedings Citation Index - Science (CPCI-S) (Web of Science Core Collection, Thomson Reuters) (1945 to January 2016), Global Health Library (Virtual Health Library), and Database of Abstracts of Reviews of Effects (DARE).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing IVIG in addition to standard care versus standard care alone or placebo.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected articles for inclusion, extracted relevant data, and assessed quality of trials. We resolved disagreements by discussion among the review authors. Where possible, we contacted authors of included studies for additional information. We presented results as risk ratios (RR) or mean differences (MD) with 95% confidence intervals (CI).

MAIN RESULTS

The search identified three RCTs with 138 participants. All three trials included only children with viral encephalitis, one of these included only children with Japanese encephalitis, a specific form of viral encephalitis. Only the trial of Japanese encephalitis (22 children) contributed to the primary outcome of this review and follow-up in that study was for three to six months after hospital discharge. There was no follow-up of participants in the other two studies. We identified one ongoing trial.For the primary outcomes, the results showed no significant difference between IVIG and placebo when used in the treatment of children with Japanese encephalitis: significant disability (RR 0.75, 95% CI 0.22 to 2.60; P = 0.65) and serious adverse events (RR 1.00, 95% CI 0.07 to 14.05; P = 1.00).For the secondary outcomes, the study of Japanese encephalitis showed no significant difference between IVIG and placebo when assessing significant disability at hospital discharge (RR 1.00, 95% CI 0.60 to 1.67). There was no significant difference (P = 0.53) in Glasgow Coma Score at discharge between IVIG (median score 14; range 3 to 15) and placebo (median 14 score; range 7 to 15) in the Japanese encephalitis study. The median length of hospital stay in the Japanese encephalitis study was similar for IVIG-treated (median 13 days; range 9 to 21) and placebo-treated (median 12 days; range 6 to 18) children (P = 0.59).Pooled analysis of the results of the other two studies resulted in a significantly lower mean length of hospital stay (MD -4.54 days, 95% CI -7.47 to -1.61; P = 0.002), time to resolution of fever (MD -0.97 days, 95% CI -1.25 to -0.69; P < 0.00001), time to stop spasms (MD -1.49 days, 95% CI -1.97 to -1.01; P < 0.00001), time to regain consciousness (MD -1.10 days, 95% CI -1.48 to -0.72; P < 0.00001), and time to resolution of neuropathic symptoms (MD -3.20 days, 95% CI -3.34 to -3.06; P < 0.00001) in favour of IVIG when compared with standard care.None of the included studies reported other outcomes of interest in this review including need for invasive ventilation, duration of invasive ventilation, cognitive impairment, poor adaptive functioning, quality of life, number of seizures, and new diagnosis of epilepsy.The quality of evidence was very low for all outcomes of this review.

AUTHORS' CONCLUSIONS

The findings suggest a clinical benefit of adjunctive IVIG treatment for children with viral encephalitis for some clinical measures (i.e. mean length of hospital stay, time (days) to stop spasms, time to regain consciousness, and time to resolution of neuropathic symptoms and fever. For children with Japanese encephalitis, IVIG had a similar effect to placebo when assessing significant disability and serious adverse events.Despite these findings, the risk of bias in the included studies and quality of the evidence make it impossible to reach any firm conclusions on the efficacy and safety of IVIG as add-on treatment for children with encephalitis. Furthermore, the included studies involved only children with viral encephalitis, therefore findings of this review cannot be generalised to all forms of encephalitis. Future well-designed RCTs are needed to assess the efficacy and safety of IVIG in the management of children with all forms of encephalitis. There is a need for internationally agreed core outcome measures for clinical trials in childhood encephalitis.

Herpes simplex virus-induced anti-N-methyl-d-aspartate receptor encephalitis: a systematic literature review with analysis of 43 cases

AIM

To conduct a systematic literature review on patients with biphasic disease with herpes simplex virus (HSV) encephalitis followed by anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis.

METHOD

We conducted a case report and systematic literature review (up to 10 December 2016), focused on differences between herpes simplex encephalitis (HSE) and anti-NMDAR encephalitis phases, age-related characteristics of HSV-induced anti-NMDAR encephalitis, and therapy. For statistical analyses, McNemar's test, Fisher's test, and Wilcoxon rank sum test were used (two-tailed significance level set at 5%).

RESULTS

Forty-three patients with biphasic disease were identified (31 children). Latency between HSE and anti-NMDAR encephalitis was significantly shorter in children than adults (median 24 vs 40.5d; p=0.006). Compared with HSE, anti-NMDAR encephalitis was characterized by significantly higher frequency of movement disorder (2.5% vs 75% respectively; p<0.001), and significantly lower rate of seizures (70% vs 30% respectively; p=0.001). Compared with adults, during anti-NMDAR encephalitis children had significantly more movement disorders (86.7% children vs 40% adults; p=0.006), fewer psychiatric symptoms (41.9% children vs 90.0% adults; p=0.025), and a slightly higher median modified Rankin Scale score (5 in children vs 4 in adults; p=0.015). During anti-NMDAR encephalitis, 84.6 per cent of patients received aciclovir (for ≤7d in 22.7%; long-term antivirals in 18.0% only), and 92.7 per cent immune therapy, but none had recurrence of HSE clinically or using cerebrospinal fluid HSV polymerase chain reaction (median follow-up 7mo).

INTERPRETATION

Our review suggests that movement disorder may help differentiate clinically an episode of HSV-induced anti-NMDAR encephalitis from HSE relapse. Compared with adults, children have shorter latency between HSE and anti-NMDAR encephalitis and, during anti-NMDAR encephalitis, more movement disorder, fewer psychiatric symptoms, and slightly more severe disease. According to our results, immune therapy given for HSV-induced anti-NMDAR encephalitis does not predispose patients to HSE recurrence.

Herpes Simplex Encephalitis: an Update

PURPOSE OF REVIEW

The goal of this review is to provide an update on current thinking regarding herpes simplex encephalitis (HSE), emphasizing new information about pathogenesis, diagnosis, and immune responses. Specific questions to be addressed are the following: (1) Is there a genetic predisposition to HSE? (2) What clinical approaches have the greatest impact on improving the long-term outcomes in patients with HSE? And (3) are there immune-mediated mechanisms that may account for relapsing HSE?

RECENT FINDINGS

Toll-like receptor 3 (TLR 3) plays an important role in innate immune responses, including generation of interferons. Multiple single-gene errors in TLR 3 interferon pathways have recently been described in children that result in increased susceptibility to HSE. Conversely, studies in both animal models and humans indicate that both cytolytic viral replication and immune-mediated responses (including cytotoxic T lymphocytes and immune mechanisms mediated by TLR 2) contribute to the pathology of HSV, suggesting possible new therapeutic approaches. In terms of treatment, data clearly indicate that a longer duration between onset of symptoms and initiation of effective antiviral therapy correlates directly with less favorable clinical outcome. Recurrent or relapsing HSE may occasionally occur, but recent observations indicate that many instances of "relapsing HSE", especially in children, are more often anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis triggered by the antecedent HSV infection. Innate immune responses are critical for defense against HSV; genetic defects in this system may predispose patients to HSE. During acute HSE, exuberant immune responses may contribute to the CNS pathology, suggesting that selective immunosuppressive therapy, coupled with potent antiviral drugs, may eventually play a role in the therapeutic management of HSV. While overall clinical outcomes of HSE remain suboptimal, the initiation of high-dose acyclovir therapy as early as possible in the course of the illness provides the best chance for a patient to survive with minimal neurologic damage. Distinguishing relapsing HSE from autoimmune anti-NMDAR antibody encephalitis is critically important because therapeutic approaches will be very different.

N-methyl-d-aspartate receptor autoimmunity affects cognitive performance in herpes simplex encephalitis

OBJECTIVES

To investigate the prevalence and temporal development of N-methyl-d-aspartate receptor (NMDAR) autoantibodies in relation to neurocognitive performance in patients with herpes simplex encephalitis (HSE).

METHODS

This prospective observational study enrolled a total of 49 HSE patients within a randomized controlled trial of valacyclovir. Cerebrospinal fluid and serum samples were drawn in the initial stage of disease, after 2 to 3 weeks and after 3 months. Anti-NMDAR IgG was detected with HEK293 cells transfected with plasmids encoding the NMDA NR1 type glutamate receptor. A batch of neurocognitive tests, including the Mattis Dementia Rating Scale (MDRS), Glasgow Coma Scale (GCS), Reaction Level Scale (RLS85), Mini-Mental State Examination (MMSE) and National Institutes of Health (NIH) stroke scale, was performed during 24 months' follow-up.

RESULTS

Anti-NMDAR IgG was detected in 12 of 49 participants. None were antibody positive in the initial stage of disease. In ten of 12 positive cases, specific antibodies were detectable only after 3 months. Notably, the development of NMDAR autoantibodies was associated with significantly impaired recovery of neurocognitive performance. After 24 months' follow-up, the median increase in MDRS total score was 1.5 vs. 10 points in antibody-positive and -negative participants (p=0.018).

CONCLUSIONS

Anti-NMDAR autoimmunity is a common complication to HSE that develops within 3 months after onset of disease. The association to impaired neurocognitive recovery could have therapeutical implications, as central nervous system autoimmunity is potentially responsive to immunotherapy.

Clinical outcomes in children with herpes simplex encephalitis receiving steroid therapy

BACKGROUND

Herpes simplex virus encephalitis (HSE) is a significant cause of morbidity and mortality. Neurologic sequelae are common even after early initiation of acyclovir treatment. The host immune response during HSE can also lead to brain damage. There are an increasing number of reports favoring steroid use in HSE.

OBJECTIVES

We aimed to compare the prognosis of children with HSE with and without steroid therapy.

STUDY DESIGN

We retrospectively screened our hospital archive from 2009 to 2014 for patients diagnosed with HSE with a positive result for herpes simplex virus polymerase chain reaction in cerebrospinal fluid. Patients ≥1 month and ≤18 years at diagnosis were included in the study. Clinical outcomes in terms of cognitive function, motor function, electroencephalographic findings, seizure frequency, and radiologic findings were compared in patients who received adjuvant steroid therapy with those who did not.

RESULTS

Six patients (1 boy, 5 girls; aged 4 months to 10 years) were included. Overall symptom duration before hospital admission was ≤5days. Patients received acyclovir treatment for 21-28days. Three received steroid therapy early during the disease and three patients did not. No adverse effects related to steroids were observed. Follow-up duration was 6 months to 5 years. All patients had radiologic sequelae of encephalitis. Cognition, motor function, and seizure control were better in patients who received steroid therapy.

CONCLUSIONS

Adjuvant steroid therapy seems to be effective in decreasing morbidity in children with HSE but the radiologic sequelae were the same in both groups.

Herpes Simplex Encephalitis: Lack of Clinical Benefit of Long-term Valacyclovir Therapy

BACKGROUND

Despite the proven efficacy of acyclovir (ACV) therapy, herpes simplex encephalitis (HSE) continues to cause substantial morbidity and mortality. Among patients with HSE treated with ACV, the mortality rate is approximately 14%-19%. Among survivors, 45%-60% have neuropsychological sequelae at 1 year. Thus, improving therapeutic approaches to HSE remains a high priority.

METHODS

Following completion of a standard course of intravenous ACV, 87 adult patients with HSE (confirmed by positive polymerase chain reaction [PCR] for herpes simplex virus DNA in cerebrospinal fluid) were randomized to receive either valacyclovir (VACV) 2 g thrice daily (n = 40) or placebo tablets (n = 47) for 90 days (12 tablets of study medication daily). The primary endpoint was survival with no or mild neuropsychological impairment at 12 months, as measured by the Mattis Dementia Rating Scale (MDRS). Logistic regression was utilized to assess factors related to the primary endpoint.

RESULTS

The demographic characteristics of the 2 randomization groups were statistically similar with no significant differences in age, sex, or race. At 12 months, there was no significant difference in the MDRS scoring for VACV-treated vs placebo recipients, with 85.7% and 90.2%, respectively, of patients demonstrating no or mild neuropsychological impairment (P = .72). No significant study-related adverse events were encountered in either treatment group.

CONCLUSIONS

Following standard treatment with intravenous ACV for PCR-confirmed HSE, an additional 3-month course of oral VACV therapy did not provide added benefit as measured by neuropsychological testing 12 months later in a population of relatively high-functioning survivors.

CLINICAL TRIALS REGISTRATION

NCT00031486.

Relationship of herpes simplex encephalitis and transcranial direct current stimulation--a case report

We report a rare case of relapsing herpes simplex encephalitis in a-37-year-old patient which was previously confirmed by positive polymerase chain reaction, herpes simplex virus (HSV) type1 IgG antibodies in cerebrospinal fluid and characterized on MRI. During the first admission, he was treated with continuous acyclovir treatment for one month with clinical improvement except for residual aphasia, for which he received a course of outpatient transcranial direct current stimulation (tDCS). A constant current of 1.2 mA was applied for 20 min twice daily. After the 4th day the patient was found to be irritable and uncooperative by staff and family members. A subsequent MRI showed significant deterioration of the lesion on comparison to the first MRI which led to discontinuation of tDCS.The relatively rapid exacerbation of HSV in only a few days is unusual. Our aim is to discuss if tDCS is related to HSV relapse and in doing so highlight possible mechanisms.

Update on herpes virus infections of the nervous system

Herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2) are human neurotropic viruses that establish latent infection in dorsal root ganglia (DRG) for the entire life of the host. From the DRG they can reactivate to cause human morbidity and mortality. Although they vary, in part, in the clinical disorders they cause, and in their molecular structure, they share several features that govern the biology of their infection of the human nervous system. HSV-1 is the causative agent of encephalitis, corneal blindness, and several peripheral nervous system disorders; HSV-2 is responsible for meningoencephalitis in neonates and meningitis in adults. The biology of their ability to establish latency, maintain it for the entire life of the host, reactivate, and cause primary and recurrent disease is being studied in animal models and in humans. This review covers recent advances in understanding the biology and pathogenesis of HSV-related disease.

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.

Are steroids a beneficial adjunctive therapy in the immunosuppressed patient with herpes simplex virus encephalitis?

Few reports describe the reactivation of latent herpes simplex virus causing encephalitis (HSVE) in patients undergoing brain radiation therapy and a concomitant steroid regimen. The role for steroid use in the treatment of patients with HSVE has not been fully elucidated. We report the case of a female patient immunosuppressed by steroids and brain radiation who developed HSVE and responded to acyclovir and dexamethasone.

The case for immunomodulatory approaches in treating HSV encephalitis

HSV encephalitis (HSE) is the most prevalent sporadic viral encephalitis. Although safe and effective antiviral therapies and greatly improved noninvasive diagnostic procedures have significantly improved outcomes, mortality (~20%) and debilitating neurological sequelae in survivors remain unacceptably high. An encouraging new development is that the focus is now shifting away from the virus exclusively, to include consideration of the host immune response to infection in the pathology underlying development of HSE. In this article, the authors discuss results from recent studies in experimental mouse models, as well as clinical reports that demonstrate a role for exaggerated host inflammatory responses in the brain in the development of HSE that is motivating researchers and clinicians to consider new therapeutic approaches for treating HSE. The authors also discuss results from a few studies that have shown that immunomodulatory drugs can be highly protective against HSE, which supports a role for deleterious host inflammatory responses in HSE. The impressive outcomes of some immunomodulatory approaches in mouse models of HSE emphasize the urgent need for clinical trials to rigorously evaluate combination antiviral and immunomodulatory therapy in comparison with standard antiviral therapy for treatment of HSE, and support for such an initiative is gaining momentum.

Glucocorticoid treatment of MCMV infected newborn mice attenuates CNS inflammation and limits deficits in cerebellar development

Infection of the developing fetus with human cytomegalovirus (HCMV) is a major cause of central nervous system disease in infants and children; however, mechanism(s) of disease associated with this intrauterine infection remain poorly understood. Utilizing a mouse model of HCMV infection of the developing CNS, we have shown that peripheral inoculation of newborn mice with murine CMV (MCMV) results in CNS infection and developmental abnormalities that recapitulate key features of the human infection. In this model, animals exhibit decreased granule neuron precursor cell (GNPC) proliferation and altered morphogenesis of the cerebellar cortex. Deficits in cerebellar cortical development are symmetric and global even though infection of the CNS results in a non-necrotizing encephalitis characterized by widely scattered foci of virus-infected cells with mononuclear cell infiltrates. These findings suggested that inflammation induced by MCMV infection could underlie deficits in CNS development. We investigated the contribution of host inflammatory responses to abnormal cerebellar development by modulating inflammatory responses in infected mice with glucocorticoids. Treatment of infected animals with glucocorticoids decreased activation of CNS mononuclear cells and expression of inflammatory cytokines (TNF-α, IFN-β and IFNγ) in the CNS while minimally impacting CNS virus replication. Glucocorticoid treatment also limited morphogenic abnormalities and normalized the expression of developmentally regulated genes within the cerebellum. Importantly, GNPC proliferation deficits were normalized in MCMV infected mice following glucocorticoid treatment. Our findings argue that host inflammatory responses to MCMV infection contribute to deficits in CNS development in MCMV infected mice and suggest that similar mechanisms of disease could be responsible for the abnormal CNS development in human infants infected in-utero with HCMV.

Neurocritical care of patients with central nervous system infections

Bacterial meningitis and viral encephalitis are life-threatening infections with high mortality rates. Patients who survive these infections often remain permanently disabled. Potential neurologic complications requiring careful attention include impaired consciousness, elevated intracranial pressure (ICP), hydrocephalus, stroke, and seizures. Systemic complications are also common and are frequently the immediate cause of death. The importance of emergent administration of appropriate antimicrobial therapy cannot be overstated, but critical care of these patients should focus not only on treatment of the underlying infection and its immediate complications but also on minimizing secondary brain injury. Given the increasing complexity of the diagnostic and therapeutic modalities available to manage central nervous system (CNS) infections, the involvement of neurocritical care units and neurointensivists may be particularly helpful in improving outcomes. It is our opinion that ICP measurement should be strongly considered in selected patients with CNS infections, particularly those who are comatose. Treatments for intracranial hypertension, specifically in the setting of CNS infection, are described in this paper. For bacterial meningitis, intravenous dexamethasone should be administered, beginning concomitantly with the initial dose of antibiotics, at least until Streptococcus pneumoniae can be excluded as a pathogen. Clinicians should maintain a high index of suspicion for nonconvulsive seizures. Deterioration in neurologic status should also prompt early use of CT or magnetic resonance angiography and venography to exclude cerebrovascular complications.

Poor neurological sequelae of herpes simplex virus encephalitis in an infant despite adequate antiviral and adjunct corticosteroid therapy

A 2-month-old infant presented to our emergency department with fever, altered consciousness, and focal seizures of acute onset. He had vesicular skin lesions over the right preauricular region. CT brain showed a large hypodense lesion involving the left temporo-parietal region, left basal ganglia and left thalamus. MRI brain revealed bilateral multifocal corticomedullary lesions suggestive of encephalitis. CSF-PCR was positive for herpes simplex virus (HSV) type I. He was treated with standard dose intravenous acyclovir for 15 days along with a trial of pulse methylprednisolone, but was readmitted within a week with features of an early relapse. The infant survived but developed significant neurological sequelae. Although treatment of HSV is available, the neurological outcome is guarded even with adequate antiviral therapy. Adjunct corticosteroid therapy did not appear to attenuate the neurological sequelae.

Neurocritical care of patients with central nervous system infections

Bacterial meningitis and viral encephalitis are life-threatening infections with high mortality rates. Patients who survive these infections often remain permanently disabled. Potential neurologic complications requiring careful attention include impaired consciousness, elevated intracranial pressure, hydrocephalus, stroke, and seizures. Systemic complications are also common and are frequently the immediate cause of death. Critical care of these patients should focus not only on treatment of the underlying infection and its immediate complications but also on minimizing secondary brain injury. Given the increasing complexity of the diagnostic and therapeutic modalities available in managing central nervous system infections, the involvement of neurocritical care units and neurointensivists may be particularly helpful in improving outcomes.

Nodavirus encephalopathy in turbot (Scophthalmus maximus): inflammation, nitric oxide production and effect of anti-inflammatory compounds

Nodaviruses are the etiological agents of one of the most serious viral diseases affecting marine fish aquaculture. Nodavirus infection produces an abnormal swimming behaviour and causes encephalopathy and retinopathy associated to important mortalities. The expression of TNF-alpha, IRF-1 and Mx was increased in turbot after nodavirus infection. A significant increase in the production of nitrogen radicals was also observed in experimentally infected turbot. Several anti-inflammatory compounds (the antioxidant N-acetylcysteine, cortisone, dexamethasone, prednisolone and aminoguanidine) were assayed to determine the role of inflammation on nodavirus infection. Cortisone and aminoguanidine were able to accelerate the mortality onset associated to nodavirus infection, modulating the gene expression of TNF-alpha and, in addition, modifying the arrival time of nodavirus to the brain. These results suggest the importance of early inflammatory processes to overcome the infection.

Protocol for German trial of Acyclovir and corticosteroids in Herpes-simplex-virus-encephalitis (GACHE): a multicenter, multinational, randomized, double-blind, placebo-controlled German, Austrian and Dutch trial [ISRCTN45122933]

BACKGROUND

The treatment of Herpes-simplex-virus-encephalitis (HSVE) remains a major unsolved problem in Neurology. Current gold standard for therapy is acyclovir, a drug that inhibits viral replication. Despite antiviral treatment, mortality remains up to 15%, less than 20% of patients are able to go back to work, and the majority of patients suffer from severe disability. This is a discouraging, unsatisfactory situation for treating physicians, the disabled patients and their families, and constitutes an enormous burden to the public health services. The information obtained from experimental animal research and from recent retrospective clinical observations, indicates that a substantial benefit in outcome can be expected in patients with HSVE who are treated with adjuvant dexamethasone. But currently there is no available evidence to support the routine use of adjuvant corticosteroid treatment in HSVE. A randomized multicenter trial is the only useful instrument to address this question.

DESIGN

GACHE is a multicenter, randomized, double-blind, placebo-controlled, parallel group clinical trial of treatment with acyclovir and adjuvant dexamethasone, as compared with acyclovir and placebo in adults with HSVE. The statistical design will be that of a 3-stage-group sequential trial with potential sample size adaptation in the last stage.

CONCLUSION

372 patients with proven HSVE (positive HSV-DNA-PCR), aged 18 up to 85 years; with focal neurological signs no longer than 5 days prior to admission, and who give informed consent will be recruited from Departments of Neurology of academic medical centers in Germany, Austria and The Netherlands. Sample size will potentially be extended after the second interim analysis up to a maximum of 450 patients.

TRIAL REGISTRATION

Current Controlled TrialsISRCTN45122933.

The immune response to herpes simplex virus type 1 infection in susceptible mice is a major cause of central nervous system pathology resulting in fatal encephalitis

This study was undertaken to investigate possible immune mechanisms in fatal herpes simplex virus type 1 (HSV-1) encephalitis (HSE) after HSV-1 corneal inoculation. Susceptible 129S6 (129) but not resistant C57BL/6 (B6) mice developed intense focal inflammatory brain stem lesions of primarily F4/80(+) macrophages and Gr-1(+) neutrophils detectable by magnetic resonance imaging as early as day 6 postinfection (p.i.). Depletion of macrophages and neutrophils significantly enhanced the survival of infected 129 mice. Immunodeficient B6 (IL-7R(-/-) Kit(w41/w41)) mice lacking adaptive cells (B6-E mice) and transplanted with 129 bone marrow showed significantly accelerated fatal HSE compared to B6-E mice transplanted with B6 marrow or control nontransplanted B6-E mice. In contrast, there was no difference in ocular viral shedding in B6-E mice transplanted with 129 or B6 bone marrow. Acyclovir treatment of 129 mice beginning on day 4 p.i. (24 h after HSV-1 first reaches the brain stem) reduced nervous system viral titers to undetectable levels but did not alter brain stem inflammation or mortality. We conclude that fatal HSE in 129 mice results from widespread damage in the brain stem caused by destructive inflammatory responses initiated early in infection by massive infiltration of innate cells.

Emergency department management of meningitis and encephalitis

Bacterial meningitis and viral encephalitis are infectious disease emergencies that can cause significant patient morbidity and mortality. Clinicians use epidemiologic, historical, and physical examination findings to identify patients at risk for these infections, and central nervous system (CNS) imaging and lumbar puncture (LP) may be needed to further evaluate for these diagnoses. The diagnosis of bacterial meningitis can be challenging, as patients often lack some of the characteristic findings of this disease with presentations that overlap with more common disorders seen in the emergency department. This article addresses considerations in clinical evaluation, need for CNS imaging before LP, interpretation of cerebrospinal fluid results, standards for and effects of timely antibiotic administration, and recommendations for specific antimicrobial therapy and corticosteroids.

Drug Insight: steroids in CNS infectious diseases--new indications for an old therapy

Infectious diseases of the CNS lead to overwhelming inflammatory processes within the brain and spinal cord that contribute substantially to patient morbidity and mortality. Pharmacological strategies to modulate inflammation have been investigated, although the resulting guidelines have sometimes been contradictory. Steroids have been proposed as adjunctive treatments for bacterial meningitis, tuberculous meningitis and herpes simplex virus encephalitis. Well-designed randomized controlled trials have established dexamethasone as an adjunctive therapy for adult patients receiving antibiotics for bacterial meningitis, and physicians prescribing the initial antibiotics need to be aware of current guidelines. Morbidity and mortality in patients with tuberculous meningitis exceeds 50%. Steroid treatments reduce mortality through an as yet unknown mechanism, although their effects on morbidity are less clear. Herpes simplex virus encephalitis is also associated with considerable morbidity and mortality. Despite a lack of randomized trials, there is some evidence that steroids used alongside antiviral therapy might be beneficial in this condition. As we discuss in this Review, systemic steroid treatment is an important aspect of treatment regimens for CNS infectious diseases, and the recent literature provides guidelines for the use of steroids in combination with appropriate antimicrobial therapy.

Occult herpes simplex virus colonization of bullous dermatitides

BACKGROUND

Acantholytic disorders, including pemphigus vulgaris, chronic benign familial pemphigus (Hailey-Hailey disease, superficial pemphigus), Darier disease, and Grover transient acantholytic dermatosis, as well as other vesiculo-bullous disorders, including bullous pemphigoid, epidermolysis bullosa, and atopic dermatitis, are prone to florid infections by herpes simplex virus (HSV)-I and -II, and, more rarely, by varicella-zoster virus (VZV). As these infections are difficult to recognize clinically and histologically, their frequency remains unknown. A possible occult viral colonization has never been documented in these disorders. The manner in which the primary bullous disorders are contaminated by herpesviridae remains unclear.

OBJECTIVE

To retrospectively assess the possible presence of HSV and VZV in a series of biopsies of acantholytic disorders and bullous pemphigoid.

METHOD

The typical alpha-herpesviridae-related cytopathic signs were searched for by conventional microscopy in skin biopsies of patients with bullous pemphigoid (n = 20), pemphigus vulgaris (n = 19), Darier disease (n = 18), chronic benign familial pemphigus (n = 3), and Grover transient acantholytic dermatosis (n = 3). Immunohistochemistry (IHC) targeted specific HSV-I, HSV-II, and VZV antigens. Polymerase chain reaction (PCR) was used for detecting HSV- and VZV-specific DNA sequences.

RESULTS

No cytopathic signs suggestive of HSV or VZV infection were detected. However, IHC revealed HSV antigens in Darier disease (1/18, HSV-I), Grover transient acantholytic dermatosis (1/3, HSV-I), pemphigus vulgaris (1/19, HSV-I), and bullous pemphigoid (2/20, HSV-I and HSV-II). In these IHC-positive cases, PCR amplified specific HSV primers in Darier disease (1/18), pemphigus vulgaris (1/19), and bullous pemphigoid (1/20). VZV antigens and nucleic acids were never identified. The HSV antigens were nearly always restricted to the upper part of the granular layer and thus differed from the usual HSV distribution during cutaneous infection. Negative and positive controls yielded consistently positive and negative results, respectively.

CONCLUSION

This report shows for the first time that clinically and histologically occult HSV colonization may occur in Darier disease, Grover transient acantholytic disease, pemphigus vulgaris, and bullous pemphigoid. Given the frequent use of immunosuppressive treatments for primary bullous disorders, greater awareness of HSV colonization and infection is recommended in these patients.

Steroids for deteriorating herpes simplex virus encephalitis

A 16-month-old girl presented with herpes simplex virus type 1 encephalitis with involvement of bilateral parietofrontal lobes, left thalamus and cerebellum. She was treated with intravenous acyclovir. As her condition deteriorated, high-dose methylprednisolone was administered, resulting in remarkable improvement. This case suggests considering a short course of high-dose steroid therapy in severe herpes simplex encephalitis when there is clinical and radiologic deterioration in spite of appropriate antiviral therapy and decreasing viral load in the cerebrospinal fluid.

Herpes simplex virus central nervous system relapse during treatment of infantile spasms with corticotropin

Here we report an infant who had herpes simplex virus (HSV) encephalitis and sustained severe bilateral damage to the posterior frontal lobes, postcentral gyri, and the thalami despite intravenous acyclovir treatment. At 7 months of age, the patient developed infantile spasms and was treated with corticotropin injections. After 10 days of corticotropin treatment, she developed lethargy, fever, and opisthotonic posturing. Her cerebrospinal fluid again was positive for HSV DNA, indicating recurrent HSV encephalitis, and repeat MRI revealed new lesions of the right frontal, parietal, temporal, and occipital lobes. Immunosuppression by corticotropin may have led to the reactivation of the HSV encephalitis. Corticotropin should be relatively contraindicated for use when a patient has a history of HSV infection, or intravenous acyclovir should be administered concurrently.

Modulation of sFas indicates apoptosis in human herpes simplex encephalitis

Herpes simplex encephalitis (HSE) is the most common cause of non-epidemic, acute and fatal viral encephalitis. A pronounced mortality and morbidity remains in HSE despite antiviral treatment. There is evidence of a vigorous intrathecal immune activity in acute phases of HSE and of persistently increased activity at follow-ups after years. The role of apoptosis of neuronal cells in HSE patients as a mechanism of damage has been brought up lately. We hypothesize that the severity and the progression of the cerebral injury resulting from HSE can be evaluated by quantitative measurement of a compartment of immune activation molecules i.e. soluble Fas (sFas) involved in apoptosis through the Fas/Fas Ligand pathway. Consecutive cerebrospinal fluid (CSF) samples from a prospectively followed cohort, included in an antiviral treatment trial in HSE, were enrolled for quantitative measurement of sFas using commercial capture ELISA. In total, CSF samples from 49 patients with HSE, 63 patients with non-HSE encephalitis and 18 healthy individuals were studied. High levels of sFas were expressed in CSF samples collected between days 0-45 after neurological onset in 41/49 (84%) HSE patients, whereas only 21/63 (33%) of non-HSE patients and none of 18 healthy controls demonstrated measurable levels of sFas. Following the consecutive CSF sFas levels over the time and considering the clinical state of patients at admission, their neurological or lethal outcome at 12 months, and antiviral treatment, we observed that HSE patients with severe neurological sequels revealed an increase in changes of CSF sFas as compared to patients with mild or moderate neurological outcome (57.6+/-55.6 pg/ml, n=10 versus 26.3+/-97.5 pg/ml, n=14; P=0.008). Also HSE patients undergoing vidarabine treatment expressed significantly higher levels of changes of CSF sFas when compared to acyclovir-treated patients (63.7+/-52.8 pg/ml, n=9 versus 26.1+/-98.4 pg/ml, n=14; P=0.003). Interestingly, regardless of the clinical state at admission, and subsequent disease progression of the HSE patients, we could not observe any significant differences in the CSF sFas levels during the first 7 days of neurological symptoms. These observations underline the role of immunological response throughout the course of HSV infection in the brain and the role of the Fas/FasL pathway in particular in disease progression of HSE. The findings further enforce the need of expanding the knowledge of the pathogenesis of HSE to direct to more effective, in particular not only antiviral but also anti-apoptotic or anti-inflammatory treatment.

Evaluation of combination therapy using aciclovir and corticosteroid in adult patients with herpes simplex virus encephalitis

OBJECTIVE

Herpes simplex virus encephalitis (HSVE) is associated with significant morbidity and mortality, even with appropriate antiviral therapy. In the present investigation, the first to assess efficacy of corticosteroid treatment with aciclovir therapy in HSVE, multiple logistic regression analysis was performed of predictors of outcome in adult patients with HSVE.

METHODS

A non-randomised retrospective study of 45 patients with HSVE treated with aciclovir was conducted. The patients were divided into poor and good groups based on outcome at three months after completion of aciclovir treatment. The variables evaluated were: clinical variables (sex, age, days after onset at initiation of aciclovir, Glasgow Coma Scale (GCS) at initiation of aciclovir, initial and maximum values for the cell numbers and protein concentration in the cerebrospinal fluid, and corticosteroid administration); neuroradiological variables (detection of lesions by initial cranial computed tomography and by initial magnetic resonance imaging); and one neurophysiological variable (detection of periodic lateralised epileptiform discharges on the initial electroencephalogram). Single variable logistic regression analysis was performed followed by multiple logistic regression analysis. The best set of predictors for the outcome of HSVE was estimated by stepwise logistic regression analysis.

RESULTS

A poor outcome was evident with older age, lower GCS score at initiation of aciclovir, and no administration of corticosteroid. Patient age, GCS at initiation of aciclovir, and corticosteroid administration were found to be significant independent predictors of outcome on multiple logistic regression analysis, and these three variables also formed the best set of predictors (R(2) = 0.594, p<0.0001).

CONCLUSION

Combination therapy using both aciclovir and corticosteroid represents one of the predictors of outcome in HSVE.

Uncommon complication of herpes simplex encephalitis

A 9-year-old-girl who had herpes simplex encephalitis developed impending uncal herniation requiring surgical decompression. This case highlights the development of an uncommon complication despite the early initiation of treatment with acyclovir.

Experimental herpes simplex virus encephalitis: a combination therapy of acyclovir and glucocorticoids reduces long-term magnetic resonance imaging abnormalities

Despite early antiviral treatment, herpes simples virus encephalitis (HSVE) still remains a life-threatening sporadic disease with high mortality and morbidity. In patients and in experimental disease, chronic progressive magnetic resonance imaging (MRI) abnormalities have been found even after antiviral therapy. Secondary autoimmune-mediated and not directly virus-mediated mechanisms might play a key role for the outcome of disease. This study aimed to evaluate a possible beneficial effect of a therapy of acyclovir and corticosteroids versus acyclovir only. In a mouse model of HSVE (intranasal inoculation with 10(5) pfu [plaque-forming units] of HSV-1 strain F), a long-term MRI study was realized. Cranial MRI was performed serially at days 2, 7, 14, 21, 60, and 180 in different therapy groups: 1, saline; 2, acyclovir; 3, acyclovir, subsequently methylprednisolone; 4, sham-infected with saline. Brain viral load peaked at day 7 to decline thereafter to a low baseline value. Viral load in group 1 was significantly higher than in animals with antiviral therapy. In group 4, no viral DNA was detectable. Viral load did not differ significantly between acyclovir and acyclovir/corticosteroid-treated groups, suggesting that the use of corticosteroids in addition to acyclovir does not increase viral burden. MRI findings in untreated and acyclovir-treated animals revealed chronic progressive changes. In contrast, there was a significant reduction of the severity of long-term MRI abnormalities in acyclovir/corticosteroid-treated animals. With respect to abnormal MRI findings, this study demonstrates a clear beneficial effect of an acyclovir and corticosteroid therapy without influencing brain viral load.

Anterior insular cortex: linking intestinal pathology and brain function in autism-spectrum subgroups

Autism includes deficits in communications skills and is associated with intestinal pathology. Numerous parents and some physicians report that an autistic child's attention and language improve in response to treatments which eliminate certain dietary antigens and/or which improve intestinal health. For at least some autism-spectrum children, the link between intestinal pathology, attention, and language may derive from shared neuroanatomic pathways within the anterior insular cortex (aIC); from a neurotrophic virus such as herpes simplex (HSV) migrating within afferents to the insular cortex; and/or from synaptic exhaustion in the aIC as induced by chronically inappropriate neuronal activity in the enteric nervous system and/or its vagal efferents.