A systematic review on the role of adjunctive corticosteroids in herpes simplex virus encephalitis: is timing critical for safety and efficacy?

Insights into adjunctive corticosteroid therapy in fulminant herpes simplex virus encephalitis: case analysis with contrasting outcomes

Herpes simplex virus (HSV) encephalitis, predominantly caused by HSV-1, presents with significant morbidity and mortality challenges. This research investigates the particular role of adjunctive corticosteroid therapy in fulminant HSV encephalitis through in-depth analyses of two contrasting cases. Corticosteroids show potential benefits to improve an exaggerated immune response and limit viral dissemination within the brain. Daily assessments and frequent neuroimaging, particularly using magnetic resonance imaging, aid in the management of fulminant cases. Although existing evidence relies on limited case series and retrospective comparisons, the results of the present study emphasize the necessity for large-scale controlled trials to establish definitive guidelines. The discretion of the treating neurologist governs the decision to implement corticosteroids, emphasizing the imperative need for continued research and evidence-based strategies for this challenging neurological condition.

Early-onset herpes simplex encephalitis type 1 triggered by COVID-19 disease: A case report

Coronavirus disease 2019 (COVID-19) causes a systemic inflammatory response and a temporary immunosuppression of hosts. Several reports have showed that reactivation of herpes simplex virus type 1 (HSV-1) is strongly associated with COVID-19. We present a case of a 66-year-old female, who developed HSV-1 encephalitis, showing impaired consciousness and typical MRI findings such as hyperintense lesions in the temporal lobe, insular cortices, bilateral medial frontal lobe on diffusion-weighted imaging, 7 days after the onset of COVID-19 symptoms. The number of cases of encephalitis in patients with COVID-19 is increasing. However, there has been limited reports of HSV-1 encephalitis following COVID-19, especially for cases with an interval of 7 days or less from the onset of COVID-19 symptoms to the onset of HSV-1 encephalitis. Our case highlights the importance of considering HSV-1 encephalitis in the differential when managing a patient with COVID-19-associated neurologic complications, even if it is in the early stages of COVID-19.

Characteristics of neonatal herpes simplex central nervous system disease in Australia (1997-2020)

BACKGROUND

Neonatal herpes simplex virus (HSV) central nervous system (CNS) disease can occur in isolation or as part of disseminated infection. We sought to describe neonatal HSV CNS disease in Australia over 24 years.

METHODS

Neonates (≤28 days) with confirmed HSV infection, reported prospectively to the Australian Paediatric Surveillance Unit (1997-2020), were evaluated for HSV CNS disease (laboratory confirmation with clinical evidence of encephalitis, e.g., lethargy, seizures, focal signs; and/or abnormalities on neuroimaging or electroencephalogram), and compared with neonates without CNS disease. CNS-restricted disease was compared with CNS-disseminated disease.

FINDINGS

Of 195 neonates with HSV disease; 87 (45%) had CNS disease (1.29 cases/100,000 live births per year, 95% CI: 1·04-1·59). Neonates with CNS disease were significantly more likely to be male than neonates without CNS disease (60% versus 39%, OR=2·32, 95% CI 1·29-4·18). Of the neonates with CNS disease, those with CNS-restricted disease (52/87, 60%) presented later than neonates with CNS-disseminated disease (35/87, 40%), (mean 12 versus 6 days). Twenty (23%) neonates with CNS disease died, the majority with CNS-disseminated disease (n = 19). Most neonates received aciclovir therapy (94·3%), however five neonates with unrecognised CNS disseminated disease (diagnosed at autopsy) had not been treated. Survivors of CNS disease were significantly more likely to have adverse neurological sequelae, compared with those without CNS disease (30% versus 4%, OR: 9·60, 95% CI: 2·6-35·0).

INTERPRETATION

Male neonates have a higher burden of HSV CNS disease. Despite the use of antiviral agents, morbidity following neonatal HSV CNS disease remains high. Evaluation of adjunctive therapies to improve outcomes is needed.

Diagnosing viral encephalitis and emerging concepts

PURPOSE OF REVIEW

This review offers a contemporary clinical approach to the diagnosis of viral encephalitis and discusses recent advances in the field. The neurologic effects of coronaviruses, including COVID-19, as well as management of encephalitis are not covered in this review.

RECENT FINDINGS

The diagnostic tools for evaluating patients with viral encephalitis are evolving quickly. Multiplex PCR panels are now in widespread use and allow for rapid pathogen detection and potentially reduce empiric antimicrobial exposure in certain patients, while metagenomic next-generation sequencing holds great promise in diagnosing challenging and rarer causes of viral encephalitis. We also review topical and emerging infections pertinent to neuroinfectious disease practice, including emerging arboviruses, monkeypox virus (mpox), and measles.

SUMMARY

Although etiological diagnosis remains challenging in viral encephalitis, recent advances may soon provide the clinician with additional tools. Environmental changes, host factors (such as ubiquitous use of immunosuppression), and societal trends (re-emergence of vaccine preventable diseases) are likely to change the landscape of neurologic infections that are considered and treated in clinical practice.

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.

Neurologic outcome of VZV encephalitis one year after ICU admission: a multicenter cohort study

BACKGROUND

Varicella-zoster virus (VZV) is one of the main viruses responsible of acute encephalitis. However, data on the prognosis and neurologic outcome of critically ill patients with VZV encephalitis are limited. We aimed to describe the clinical features of VZV encephalitis in the ICU and to identify factors associated with a favorable neurologic outcome. We performed a multicenter cohort study of patients with VZV encephalitis admitted in 18 ICUs in France between 2000 and 2017. Factors associated with a favorable neurologic outcome, defined by a modified Rankin Score (mRS) of 0-2 1 year after ICU admission, were identified by multivariable regression analysis.

RESULTS

Fifty-five patients (29 (53%) men, median age 53 (interquartile range 36-66)) were included, of whom 43 (78%) were immunocompromised. ICU admission occurred 1 (0-3) day after the onset of neurological symptoms. Median Glasgow Coma Score at ICU admission was 12 (7-14). Cerebrospinal fluid examination displayed a median leukocyte count of 68 (13-129)/mm³, and a median protein level of 1.37 (0.77-3.67) g/L. CT scan and MRI revealed brain lesions in 30% and 66% of the cases, respectively. Invasive mechanical ventilation was implemented in 46 (84%) patients for a median duration of 13 (3-30) days. Fourteen (25%) patients died in the ICU. One year after ICU admission, 20 (36%) patients had a favorable neurologic outcome (mRS 0-2), 12 (22%) had significant disability (mRS 3-5), and 18 (33%) were deceased (lost to follow-up n = 5, 9%). On multivariable analysis, age (OR 0.92 per year, (0.88-0.97), p = 0.01), and invasive mechanical ventilation (OR 0.09 CI 95% (0.01-0.84), p = 0.03) reduced the likelihood of favorable neurologic outcome.

CONCLUSION

One in every three critically ill patients with VZV encephalitis had a favorable neurologic outcome 1 year after ICU admission. Older age and invasive mechanical ventilation were associated with a higher risk of disability and death.

Diagnostic approach and treatment regimens in adult patients suffering from antibody-mediated or paraneoplastic encephalitis

Identification of patients with antibody-mediated encephalitis poses a diagnostic challenge and any delay in that respect will increase the interval until initiation of immunotherapy and may negatively affect the patient´s clinical outcome. Within this review we focus on therapeutic strategies in antibody-mediated encephalitis and propose how to proceed with patients, who are suspected to have encephalitis of unknown origin. We further briefly outline differences in treatment of paraneoplastic and antibody-mediated encephalitis according to its pathomechanisms.

Intensive care management of patients with viral encephalitis

Viral encephalitis is a severe syndrome that can lead to encephalopathy, seizures, focal deficits, and neurological sequelae and death. It is mainly caused by neurotropic herpes viruses (i.e., HSV and VZV), although other pathogens may be observed in specific geographic regions or conditions. Recent advances in neuroimaging and molecular biology (PCR, metagenomics) allow for faster and more accurate etiological diagnoses, although their benefits need to be confirmed to provide guidelines for their use and interpretation. Despite intravenous acyclovir therapy and supportive care, outcomes remain poor in about two-thirds of herpes encephalitis patients requiring ICU admission. Randomized clinical trials focusing on symptomatic measures (i.e. early ICU admission, fever control, and treatment of seizures/status epilepticus) or adjunctive immunomodulatory therapies (i.e. steroids, intravenous immunoglobulins) to improve neurologic outcomes have not been conducted in the ICU setting. Large prospective multicenter studies combining clinical, electrophysiological, and neuroimaging data are needed to improve current knowledge on care pathways, long-term outcomes, and prognostication.

Non-traumatic pediatric intracranial hypertension: key points for different etiologies, diagnosis, and treatment

Intracranial hypertension can be an acute life-threatening event or slowly deteriorating condition, leading to a gradual loss of neurological function. The diagnosis should be taken in a timely fashioned process, which mandates expedite measures to save brain function and sometimes life. An optimal management strategy is selected according to the causative etiology with a core treatment paradigm that can be utilized in various etiologies. Distinct etiologies are intracranial bleeds caused by traumatic brain injury, spontaneous intracranial hemorrhage (e.g., neonatal intraventricular hemorrhage), or the rare pediatric hemorrhagic stroke. The other primary pediatric etiologies for elevated intracranial pressure are intracranial mass (e.g., brain tumor) and hydrocephalus related. Other unique etiologies in the pediatric population are related to congenital diseases, infectious diseases, metabolic or endocrine crisis, and idiopathic intracranial pressure. One of the main goals of treatment is to alleviate the growing pressure and prevent the secondary injury to brain parenchyma due to inadequate blood perfusion and eventually inadequate parenchymal oxygenation and metabolic state. Previous literature discussed essential characteristics of the treatment paradigm derived mainly from pediatric brain traumatic injuries' treatment methodology. Yet, many of these etiologies are not related to trauma; thus, the general treatment methodology must be tailored carefully for each patient. This review focuses on the different possible non-traumatic etiologies that can lead to intracranial hypertension with the relevant modification of each etiology's treatment paradigm based on the current literature.

Strategies for the diagnosis and management of meningitis in HIV-infected adults in resource limited settings

INTRODUCTION

The incidence of human immunodeficiency virus-1 (HIV-1) associated meningitis has been declining in the post-combination antiretroviral treatment (ART) era, although survival rates remain low for the common causes like tuberculosis and cryptococcal disease. Diagnosis and treatment of meningitis in HIV-1 is complicated by atypical clinical presentations, limited accuracy of diagnostic tests, access to diagnostic tests, and therapeutic agents in low- and middle-income countries (LMIC) and immune reconstitution inflammatory syndrome (IRIS).

AREAS COVERED

We provide an overview of the common etiologies of meningitis in HIV-1-infected adults, suggest a diagnostic approach based on readily available tests, and review specific chemotherapeutic agents, host-directed therapies, supportive care, timing of ART initiation, and considerations in the management of IRIS with a focus on resource-limited settings. They identify key knowledge gaps and suggest areas for future research.

EXPERT OPINION

Evidence-based management of HIV-1-associated meningitis is sparse for common etiologies. More readily available and sensitive diagnostic tests as well as standardized investigation strategies are required in LMIC. There is a lack of availability of recommended drugs in areas of high HIV-1 prevalence and a limited pipeline of novel chemotherapeutic agents. Host-directed therapies have been inadequately studied.

Varicella Zoster Virus Encephalitis in Denmark From 2015 to 2019-A Nationwide Prospective Cohort Study

BACKGROUND

Knowledge of the epidemiology and clinical characteristics of varicella zoster virus (VZV) encephalitis remains limited.

METHODS

Nationwide prospective cohort study of adults treated for microbiologically confirmed VZV encephalitis at Danish departments of infectious diseases from 2015 to 2019. Modified Poisson regression analysis was used to compute adjusted relative risks (RRs) of unfavorable outcome.

RESULTS

We identified 92 adults (49% female) with VZV encephalitis, yielding an incidence of 5.3/1 000 000 per year (95% CI, 4.2-6.6). Median age was 75 years (IQR, 67-83) and immunocompromising conditions were frequent (39%). Predominant symptoms were confusion (76%), headache (56%), nausea (45%), gait disturbance (42%), and personality changes (41%). Cranial imaging showed cerebral vasculitis (including infarction and hemorrhage) in 14 (16%) patients and encephalitic abnormalities in 11 (13%) with predilection for the brainstem and deep brain structures. Intravenous acyclovir treatment was initiated a median (IQR) of 13.4 hours (5.2-46.3) since admission, while cranial imaging and lumbar puncture were performed after 6.3 hours (2.5-31.0) and 18.5 hours (4.9-42.0). In-hospital, 1-month, and 3-month mortalities were 4%, 9%, and 11%, respectively. Unfavorable outcome (Glasgow Outcome Score of 1-4) was found in 69% at discharge, with age (adjusted RR [aRR], 1.02; 95% CI, 1.01-1.03), vasculitis (aRR, 1.38; 95% CI, 1.02-1.86), and Glasgow Coma Scale (GCS) <15 (aRR, 1.32; 95% CI, 1.01-1.73) identified as independent risk factors.

CONCLUSIONS

VZV encephalitis occurs primarily in elderly or immunocompromised patients with a higher incidence than previously estimated. The diagnosis is often delayed; risk factors for unfavorable outcome are age, cerebral vasculitis, and GCS <15.

Update in Viral Infections in the Intensive Care Unit

The advent of highly sensitive molecular diagnostic techniques has improved our ability to detect viral pathogens leading to severe and often fatal infections that require admission to the Intensive Care Unit (ICU). Viral infections in the ICU have pleomorphic clinical presentations including pneumonia, acute respiratory distress syndrome, respiratory failure, central or peripheral nervous system manifestations, and viral-induced shock. Besides de novo infections, certain viruses fall into latency and can be reactivated in both immunosuppressed and immunocompetent critically ill patients. Depending on the viral strain, transmission occurs either directly through contact with infectious materials and large droplets, or indirectly through suspended air particles (airborne transmission of droplet nuclei). Many viruses can efficiently spread within hospital environment leading to in-hospital outbreaks, sometimes with high rates of mortality and morbidity, thus infection control measures are of paramount importance. Despite the advances in detecting viral pathogens, limited progress has been made in antiviral treatments, contributing to unexpectedly high rates of unfavorable outcomes. Herein, we review the most updated data on epidemiology, common clinical features, diagnosis, pathogenesis, treatment and prevention of severe community- and hospital-acquired viral infections in the ICU settings.

ASC-dependent inflammasomes contribute to immunopathology and mortality in herpes simplex encephalitis

Herpes simplex virus encephalitis (HSE) is the most common cause of sporadic viral encephalitis, and despite targeted antiviral therapy, outcomes remain poor. Although the innate immune system is critical for restricting herpes simplex virus type I (HSV-1) in the brain, there is evidence that prolonged neuroinflammation contributes to HSE pathogenesis. In this study, we investigated the contribution of inflammasomes to disease pathogenesis in a murine model of HSE. Inflammasomes are signaling platforms that activate the pro-inflammatory cytokines interleukin-1β (IL-1β) and IL-18. We found that mice deficient in the inflammasome adaptor protein, apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), had significantly improved survival and lower levels of IL-1β and IL-18 in the brain. Importantly, this difference in survival was independent of viral replication in the central nervous system (CNS). We found that microglia, the resident macrophages of the CNS, are the primary mediators of the ASC-dependent inflammasome response during infection. Using in vitro glial infections and a murine HSE model, we demonstrate that inflammasome activation contributes to the expression of chemokine (C-C motif) ligand 6 (CCL6), a leukocyte chemoattractant. The lower concentration of CCL6 in the brains of ASC-/- mice correlated with lower numbers of infiltrating macrophages during infection. Together, these data suggest that inflammasomes contribute to pathogenic inflammation in HSE and provide a mechanistic link between glial inflammasome activation and leukocyte infiltration. The contribution of inflammasomes to survival was independent of viral replication in our study, suggesting a promising new target in combating harmful inflammation in HSE.

Reactivation of cyprinid herpesvirus 2 (CyHV-2) in asymptomatic surviving goldfish Carassius auratus (L.) under immunosuppression

Cyprinid herpesvirus 2 (CyHV-2) is a highly contagious pathogen of goldfish (Carassius auratus) and Prussian carp (Carassius auratus gibelio) causing herpesviral hematopoietic necrosis. Our previous study revealed that CyHV-2 can persistently infect the kidney and spleen of goldfish that recovered from a primary infection. In this study, we tried to identify the cells persistently infected with the virus in surviving fish and investigated virus reactivation in the survivors injected with immunosuppressants, namely dexamethasone (Dex) and cyclosporine A (CsA). Virus DNA was detected from the monocytes that were isolated from the trunk kidney of the asymptomatic survivors, suggesting that monocytes/macrophages are major cells that may be persistently infected with CyHV-2. A significant increase of virus DNA levels was detected in the group injected with Dex at 10 and 21 days post-injection (dpi). In the fish group injected with CsA, the virus DNA level was the same as that in the control group at 10 dpi but increased in some organs at 21 dpi. Compared with Dex-injected fish at 10 dpi, the group injected with both Dex and CsA showed a greater increase in virus DNA levels. The gene expression of phagocytosis-associated genes, major histocompatibility complex (MHC) class II and p47^phox, and anti-virus antibody levels increased in the CsA group due to virus reactivation in the infected cells but not in the Dex and Dex & CsA groups, indicating that Dex effectively suppressed monocyte/macrophage function and antibody production. In addition, recombinant interferon γ (IFNγ) supplementation in the kidney leukocyte culture that was isolated from survivors showed a reduction of virus DNA. CsA may inhibit T-helper 1 (Th1) cells and consequently IFNγ production, causing a synergetic effect with Dex on virus reactivation. The results suggest that the activity of monocytes/macrophages stimulated by IFNγ can relate to virus latency and reactivation in asymptomatic virus carriers.

Predictors of Outcome in Clinically Diagnosed Viral Encephalitis Patients: A 5-Year Prospective Study

Background

Viral encephalitis is the most common infectious disease of the central nervous system and is associated with high morbidity, mortality, and disability. The objective of this study was to analyze the clinical characteristics, auxiliary examinations, therapeutic management, and outcomes of patients clinically diagnosed with viral encephalitis and identify the outcome predictors.

Methods

We conducted a prospective observational study by collecting information from patients clinically diagnosed with viral encephalitis at the First Affiliated Hospital of Chongqing Medical University and Yongchuan Hospital of Chongqing Medical University from January 2013 to December 2018. Univariate and multivariate analyses were performed to identify factors that influenced good patient outcomes (mRS < 3) and poor patient outcomes (mRS ≥ 3) at discharge.

Results

In total, 216 patients were enrolled in the study. The multivariate analysis suggested that the following factors were associated with a poor outcome: Glasgow Coma Scale (GCS) score (OR 0.154, 95% CI (0.078-0.302), and P < 0.001), focal neurological deficits (OR 9.403, 95% CI (1.581-55.928), and P = 0.014), and total length of hospital stay (OR 1.119, 95% CI (1.002-1.250), and P = 0.045). However, neurological intensive care unit (NICU) treatment, status epilepticus, and abnormal electroencephalogram (EEG) findings did not influence the prognosis of patients.

Conclusion

Our study suggests that low GCS scores at admission, focal neurological deficits at admission, and a prolonged total hospital stay are predictors of a poor outcome at discharge in clinically diagnosed viral encephalitis patients. Whether early and effective neurological rehabilitation can improve the prognosis of viral encephalitis patients with focal neurological deficits remains to be confirmed in further studies.

Anti-NMDAR Encephalitis Following Herpes Simplex Virus Encephalitis: 2 Cases From Portugal

Herpes simplex virus encephalitis (HSVE) usually presents as a monophasic disease. Symptomatic HSVE relapsing with seizures, encephalopathy, or involuntary movements associated with anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis have been recently reported. We report 2 cases of adult post-HSVE anti-NMDAR encephalitis from Portugal. Two female patients aged 50 years and 30 years were diagnosed with herpes simplex virus type 2 and type 1 encephalitis, respectively. After the initial improvement with specific treatment and despite virologic negativization, both patients suffered clinical, electroencephalographic, and imaging deterioration. The autoimmune encephalitis hypothesis was confirmed with the demonstration of anti-NMDAR antibodies in both cerebrospinal fluid and serum. Both responded to human immunoglobulin and methylprednisolone, with progressive gain of autonomy along the follow-up period. Thymectomy for thymic hyperplasia diagnosed during follow-up was performed in 1 patient. Although being rare, post-HSVE anti-NMDAR encephalitis should be considered in all cases of symptomatic recrudescence after HSVE, since adequate immune-modulating treatment improves the outcome. The role of thyme hyperplasia in autoimmune encephalitis pathogenesis needs better understanding.

Relapse of herpes simplex encephalitis in a patient with metastatic small cell lung cancer following scalp sparing whole brain radiotherapy

Herpes simplex virus is the most common cause of severe and potentially fatal sporadic encephalitis worldwide. Recurrence of neurologic symptoms after resolution of the initial episode of HSV encephalitis and despite adequate treatment with intravenous acyclovir is well recognized albeit rare. Most of these recurrences had no evidence of replicating virus and are immune in nature with only a minority of these recurrences representing true virologic relapses. Immunocompromised patients are predominantly at greater risk for virologic relapse of HSV encephalitis with potentially severe and at times fatal consequences. We describe a patient with small cell lung cancer and brain metastasis who underwent chemotherapy, treatment with dexamethasone and whole brain radiotherapy who subsequently suffered two episodes of HSV encephalitis three months and seven months after completion of radiotherapy and while on dexamethasone treatment.

Roles of HSV-1 infection-induced microglial immune responses in CNS diseases: friends or foes?

Microglia, as brain-resident macrophages, are the first line of defense against brain invading pathogens. Further, their dysfunction has been recognized to be closely associated with mounting CNS diseases. Of note, chronic HSV-1 infection leads to the persistent activation of microglia, which elicit a comprehensive response by generating certain factors with neurotoxic and neuroprotective effects. CNS infection with HSV-1 results in herpes simplex encephalitis and herpes simplex keratitis. Microglial immune response plays a crucial role in the development of these diseases. Moreover, HSV-1 infection is strongly associated with several CNS diseases, especially Alzheimer's disease and schizophrenia. These CNS diseases can be effectively ameliorated by eliciting an appropriate immune response, such as inhibition of microglial proliferation and activation. Therefore, it is crucial to reassess the positive and negative roles of microglia in HSV-1 CNS infection for a more comprehensive and detailed understanding of the relationship between microglia and CNS diseases. Hence, the present review focuses on the dual roles of microglia in mediating HSV-1 CNS infection, as well as on the strategy of targeting microglia to ameliorate CNS diseases. Further research in this field can help comprehensively elucidate the dual role of the microglial immune response in HSV-1 CNS infection, providing a theoretical basis for identifying therapeutic targets against overactive microglia in CNS diseases and HSV-1 infection.

Herpes simplex virus encephalitis in a patient receiving ustekinumab associated with extensive cerebral oedema and brainshift successfully treated by immunosuppression with dexamethasone

Herpes simplex virus (HSV) encephalitis affects 2-4 people per million/year. Immunocompomised patients can have atypical presentations of HSV encephalitis, including a lack of cerebrospinal fluid (CSF) pleocytosis. We present the case of a patient who was receiving ustekinumab therapy for psoriasis which inhibits interleukin (IL)-12 and IL-23 signalling pathways. The initial presentation was suggestive of encephalitis, but he was discharged prior to the reporting of HSV positivity due to the lack of CSF pleocytosis. On representation, he had worsening symptoms and imaging showed midline shift, indicating cerebral oedema despite the immunosupressant effects of ustekinumab. He required intensive care unit support and treatment with high dose aciclovir and dexamethasone; after a month of treatment he made a good recovery. This case is the first to report a link between ustekinumab and HSV encephalitis, and also emphasises that imunocompromised patients can lack CSF pleocytosis and develop significant cerebral oedema which responds to immune suppression.

Severe presentation of antibody-negative, postinfectious steroid-responsive encephalitis and atonic bladder after herpes simplex encephalitis

A 75-year-old woman presented with new onset of confusion, intense episodic dizziness and formed visual hallucinations. Herpes simplex encephalitis and non-convulsive temporal lobe seizures were confirmed with cerebrospinal fluid (CSF) and electroencephalography testing. In addition, her hospital course was complicated by syndrome of inappropriate antidiuretic hormone secretion and atonic bladder contributing to an episode of urinary tract infection. After completing 3 weeks of acyclovir treatment, the patient became obtunded with right arm choreiform movements and persistent inflammatory CSF findings not attributable to persistent herpes simplex virus infection or other confounding factors. The patient responded to steroid treatment. Repeated autoimmune and paraneoplastic evaluations were negative. Both clinical (cognitive testing and atonic bladder) and CSF inflammatory finding improved in the follow-up period.

Management of antibody-mediated autoimmune encephalitis in adults and children: literature review and consensus-based practical recommendations

Autoimmune encephalitis associated with antibodies against neuronal surface targets (NSAE) are rare but still underrecognized conditions that affect adult and pediatric patients. Clinical guidelines have recently been published with the aim of providing diagnostic clues regardless of antibody status. These syndromes are potentially treatable but the choice of treatment and its timing, as well as differential diagnoses, long-term management, and clinical and paraclinical follow-up, remain major challenges. In the absence of evidence-based guidelines, management of these conditions is commonly based on single-center expertise.Taking into account different published expert recommendations in addition to the multicenter experience of the Italian Working Group on Autoimmune Encephalitis, both widely accepted and critical aspects of diagnosis, management and particularly of immunotherapy for NSAE have been reviewed and are discussed.Finally, we provide consensus-based practical advice for managing hospitalization and follow-up of patients with NSAE.

Managing Meningoencephalitis in Indian ICU

How to cite this article: Sapra H, Singhal V. Managing Meningo-encephalitis in Indian ICU. Indian J Crit Care Med 2019;23(Suppl 2):S124-S128.

Positive Effect of Steroids in Posterior Reversible Encephalopathy Syndrome

We present a case of posterior reversible encephalopathy syndrome with severe clinical manifestation. Apart from initial aphasia, hemiparesis, and a generalized seizure, the patient had a prolonged loss of consciousness. Although blood pressure was normalized, the clinical status deteriorated continuously. After adding steroids to the therapy, the patient recovered rapidly, suggesting that this could have been a useful therapeutic approach. Even the vasogenic edema in the cerebral magnetic resonance imaging disappeared shortly within 6 days.

Corilagin Interferes With Toll-Like Receptor 3-Mediated Immune Response in Herpes Simplex Encephalitis

Herpes simplex encephalitis (HSE) is the most common infectious disease of the central nervous system worldwide. However, the pathogenesis of HSE is not clear. Research has shown that the immune response mediated by the toll-like receptor 3 (TLR3) signaling pathway is essential to protect the central nervous system against herpes simplex virus (HSV) infection. However, an excessive immune response may cause tissue damage accompanied by pathological changes. The aim of this study was to explore the molecular mechanism via which corilagin controls HSE through the TLR3 signaling pathway in vitro and in vivo. Cells and mice were pre-treated with polyriboinosinic polyribocytidylic acid [poly(I:C)] or HSV type 1, and then treated with corilagin. After treatment, the mRNA and protein levels of TLR3, TLR-like receptor-associated interferon factor (TRIF), tumor necrosis factor (TNF) receptor type 1-associated DEATH domain protein (TRADD), TNF receptor-associated factor (TRAF) 3 and 6, nuclear factor-kappa-B (NF-κB) essential modulator (NEMO), P38, and interferon regulatory factor 3 (IRF3) were decreased. Interleukin-6 (IL-6), TNF-α, and type 1 interferon-β were also decreased. When TLR3 expression was silenced or increased, corilagin still inhibited the expression of TLR3 and its downstream mediators. Hematoxylin-eosin (HE) staining and immunohistochemical examinations of mouse brain tissues revealed that corilagin lessened the degree of brain inflammation. Altogether, these results suggest that corilagin may regulate the immune response in HSE and relieve inflammatory injury by interfering with the TLR3 signaling pathway.

Treatment Approaches for MOG-Ab-Associated Demyelination in Children

Purpose of review

The purpose of this review is to summarize current understanding regarding the treatment of myelin oligodendrocyte glycoprotein antibody (MOG-Ab)-associated demyelination in children. Emphasis is placed on the unique obstacles we face when predicting the risk of relapse and the important implications of such challenges when planning treatment protocols.

Recent findings

MOG-Abs are consistently identified in a range of acquired demyelinating syndromes (ADS) in adults and children with a clinical phenotype distinct of MS and AQP4-Ab neuromyelitis optica spectrum disorder. Although initially thought to be associated with a benign disease, recent reports of children who are treatment-resistant and developed progressive disability over time raise important questions about how children with relapsing MOG-Ab disease should be managed.

Summary

MOG-Abs are common in children with ADS with both monophasic and relapsing disease courses. Treatment of patients with MOG-Ab-associated demyelination includes management of acute relapses and chronic immunotherapy for those with relapsing disease. Emerging consensus supports distinction of treatment strategies from those typically used for relapsing remitting MS, and several groups debate whether to follow treatment protocols akin to those for AQP4-Ab NMOSD. A key challenge remains predicting the severity of the disease at onset. Collaborative international consensus to derive shared clinical evaluative platforms standardized biological and neuroimaging protocols which can be used clinically, and partnered research programs are required to advance personalized treatment for children with MOG-Ab-associated demyelination.

Decompressive craniectomy for herpes simplex encephalitis complicated by frank intracerebral hemorrhage: a case report and review of the literature

Background

Herpes simplex encephalitis is the most common type of sporadic encephalitis worldwide. Frank intracerebral hemorrhage complicating the disease course in herpes simplex encephalitis patients is rare, especially cases where surgical decompression is necessary. Here, we report a previously healthy female with herpes simplex encephalitis who underwent surgical decompression due to temporal lobe hemorrhage.

Case presentation

A previously healthy 34-year-old Korean female presented with fever, myalgia and severe headache. Brain MRI showed a high T2 signal intensity change and diffuse swelling of the right temporal lobe. Polymerase chain reaction testing of the cerebrospinal fluid confirmed the presence of herpes simplex virus 1. The patient was admitted for close observation and intravenous acyclovir. On hospital day 3, she had a sudden onset of vomiting and severe headache. Brain CT showed frank temporal lobe hemorrhage. Despite aggressive medical treatment, she became increasingly drowsy. Ultimately, she underwent emergency right decompressive craniectomy, expansile duraplasty and intracranial pressure monitor insertion. The patient recovered fully without any neurological deficits or neuropsychological problems. She was discharged after completion of 2 weeks of acyclovir and returned 2 months later for cranioplasty.

Conclusions

Patients with severe herpes simplex encephalitis complicated by intracerebral hemorrhage or malignant cerebral edema should undergo aggressive medical treatment. Surgical decompression should also be actively considered in these severe cases to prevent further neurological deterioration.

Epidemiology and Immune Pathogenesis of Viral Sepsis

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Sepsis can be caused by a broad range of pathogens; however, bacterial infections represent the majority of sepsis cases. Up to 42% of sepsis presentations are culture negative, suggesting a non-bacterial cause. Despite this, diagnosis of viral sepsis remains very rare. Almost any virus can cause sepsis in vulnerable patients (e.g., neonates, infants, and other immunosuppressed groups). The prevalence of viral sepsis is not known, nor is there enough information to make an accurate estimate. The initial standard of care for all cases of sepsis, even those that are subsequently proven to be culture negative, is the immediate use of broad-spectrum antibiotics. In the absence of definite diagnostic criteria for viral sepsis, or at least to exclude bacterial sepsis, this inevitably leads to unnecessary antimicrobial use, with associated consequences for antimicrobial resistance, effects on the host microbiome and excess healthcare costs. It is important to understand non-bacterial causes of sepsis so that inappropriate treatment can be minimised, and appropriate treatments can be developed to improve outcomes. In this review, we summarise what is known about viral sepsis, its most common causes, and how the immune responses to severe viral infections can contribute to sepsis. We also discuss strategies to improve our understanding of viral sepsis, and ways we can integrate this new information into effective 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.

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.

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.

Management of adult infectious encephalitis in metropolitan France

Infectious encephalitis is a severe disease leading to a high mortality and morbidity. The most frequent causes include Herpes simplex virus, Varicella Zoster virus, Listeria monocytogenes, and Mycobacterium tuberculosis. Urgent treatment is required (anti-infective therapy and nonspecific supportive care). The aim of this study was to define treatment strategy, empirical and after microbiological documentation at 48hours, through a systematic literature review.

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.

Diagnosis and management of acute encephalitis

Encephalitis is typically viral (approximately half of diagnosed cases) or autoimmune (about a quarter) with the remainder remaining undiagnosable at this time. All require general supportive care but only a minority requires intensive care admission - in these intubation, to protect the airway or to treat status epilepticus with anesthetic drugs, may be needed. In some dysautonomia with wide blood pressure fluctuations is the principal concern. Remarkably, in addition to supportive care, specific treatment options are available for the majority - immune-modulating therapy for those with autoimmune disorders, antiviral therapy for herpes simplex 1 and 2, and varicella-zoster encephalitis. Flavivirus infections (West Nile, Japanese encephalitis, tick-borne encephalitis) remain the most common other identified cause of encephalitis but no specific intervention is available. Overall long-term outcomes are favorable in the majority of patients with encephalitis, a proportion that hopefully will improve with further advances in diagnostic technology and therapeutic interventions.

The Clinical Approach to Encephalitis

Encephalitis has various etiologies, but viral infections and autoimmune disorders are the most commonly identified. Clinical signs, geographical clues, and diagnostic testing-including cerebrospinal fluid abnormalities and magnetic resonance imaging abnormalities-can be helpful in identifying the cause. Certain forms of encephalitis have specific treatments; hence, establishing a diagnosis rapidly and accurately is crucial. Here, we describe the clinical approach to diagnosing several common etiologies of encephalitis as well as treatment strategies.

Valacyclovir combined with artesunate or rapamycin improves the outcome of herpes simplex virus encephalitis in mice compared to antiviral therapy alone

Despite antiviral therapy, the mortality rate of herpes simplex virus encephalitis (HSE) remains high and many surviving patients harbor neurological sequelae. Although viral replication is responsible for substantial neurological damages, an exaggerated inflammatory response could also contribute to this process. Artesunate (ART) and rapamycin (RAPA) have shown some benefits in the treatment of herpes simplex virus infections. Herein, we evaluated the benefit of combining ART or RAPA with valacyclovir (VACV) in a murine model of HSE. Infected mice were treated with VACV (1mg/mL in drinking water) from day 3 post-infection (p.i.) combined or not with daily intraperitoneal administration of ART (30mg/kg) or RAPA (20mg/kg) from days 4 to 13 p.i. Viral load, infectious titers, cytokine and chemokine levels were measured in brain homogenates on days 5, 7 and 9. The survival rates of mice treated with VACV and ART or RAPA were higher than with VACV alone (71.9% versus 43.2% for ART and 66.7% versus 43.2% for RAPA; both P⩽0.05) but no significant difference was seen in the brain viral loads. Levels of IL-1β, IL-2 (both P⩽0.05), IL-6, IFN-γ (both P⩽0.01), CCL2 (P⩽0.01), CCL3 and CCL4 (both P⩽0.05) were reduced in mice treated with VACV combined with ART versus VACV alone. Levels of IL-6, IL-1β and IFN-γ slightly increased on day 7 in mice treated with VACV combined with RAPA compared to VACV alone and then decreased on day 9. Our results suggest that immunomodulatory compounds such as ART or RAPA could benefit antiviral therapy in HSE.

Innate immune response during herpes simplex virus encephalitis and development of immunomodulatory strategies

Herpes simplex viruses are large double-stranded DNA viruses. These viruses have the ability to establish a lifelong latency in sensory ganglia and to invade and replicate in the CNS. Apart from relatively benign mucosal infections, HSV is responsible for severe illnesses including HSV encephalitis (HSE). HSE is the most common cause of sporadic, potentially fatal viral encephalitis in Western countries. If left untreated, the mortality rate associated with HSE is approximately 70%. Despite antiviral therapy, the mortality is still higher than 30%, and almost 60% of surviving individuals develop neurological sequelae. It is suggested that direct virus-related and indirect immune-mediated mechanisms contribute to the damages occurring in the CNS during HSE. In this manuscript, we describe the innate immune response to HSV, the development of HSE in mice knock-out for proteins of the innate immune system as well as inherited deficiencies in key components of the signaling pathways involved in the production of type I interferon that could predispose individuals to develop HSE. Finally, we review several immunomodulatory strategies aimed at modulating the innate immune response at a critical time after infection that were evaluated in mouse models and could be combined with antiviral therapy to improve the prognosis of HSE. In conclusion, the cerebral innate immune response that develops during HSE is a "double-edged sword" as it is critical to control viral replication in the brain early after infection, but, if left uncontrolled, may also result in an exaggerated inflammatory response that could be detrimental to the host.

Recurrence of herpes simplex encephalitis associated with temozolomide chemoradiation for malignant glioma: a case report and review of the literature

Although herpes simplex encephalitis is not classically considered an opportunistic infection, reactivation of herpes simplex is being seen increasingly in patients with cancer or immunosuppression. The authors present a patient with malignant glioma and HSV-1 encephalitis whose PCR-proven encephalitis recurred after temozolomide (TMZ) chemoradiation despite acyclovir therapy, and summarize details of four other cases of HSV-1 encephalitis associated with TMZ. The similarity among these cases raises the likely need for longer treatment courses and/or oral suppressive therapy in patients at risk for herpes simplex infections who are receiving TMZ.