Efficacy and safety of intravenous immunoglobulins for the treatment of viral encephalitis: a systematic literature review

Clinical Characteristics and Mechanism Discussion of Peripheral Nerve Injury in 2 Cases of Severe Viral Meningoencephalitis

Purpose

Peripheral neuropathy(PN) secondary to central nervous system(CNS) infections is rare in clinical practice. This study analyze the prognosis, clinical characteristics, and outcomes of patients with PN secondary to CNS infections to aid early diagnosis and improve prognosis.

Methods

Clinical data from two patients admitted to our Neurology Department with PN secondary to severe viral meningoencephalitis were collected, summarized, and analyzed. Using diagnostic tools like body fluid tests, imaging, EEG, and EMG, and based on the criteria of the International Encephalitis Consortium, encephalitis was diagnosed in Case 1 and Case 2. The European Academy of Neurology/Peripheral Nerve Society recommendations were applied to confirm patients' PN diagnosis.

Results

Patient 1 was diagnosed with encephalitis, presenting with elevated serum IL-6 levels, and received IVIG treatment upon admission. One week later, the infection remitted and IL-6 levels decreased. Physical and EMG examinations revealed peripheral nerve demyelination damage. After treatment, the nerve damage improved, and the patient had a good prognosis post-discharge. Upon admission, Patient 2 exhibited viral meningoencephalitis symptoms, with elevated serum IL-8 and normal IL-6 levels; limb muscle strength and tone were normal. Five days later, the infection deteriorated, accompanied by reduced lower limb strength, and elevated IL-6 and IL-8 in serum and CSF, with a striking peak of CSF IL-6. EMG confirmed peripheral nerve demyelination and axonal damage. Following 5-day IVIG treatment, IL-6 and IL-8 levels in serum and CSF declined. Peripheral nerve injury recovery was modest despite treatment, and the patient's prognosis remained moderate.

Conclusion

This study reported two rare cases of PN following CNS infection. Comparative analysis of symptoms, cytokine in body fluids, treatments, disease courses, and prognosis indicates that elevated peripheral and/or central cytokines, particularly IL-6 and IL-8, correlate with the severity and prognosis of this complication. IVIG modulates inflammation, and its administration timing likely determines differential outcomes.

An autochthonous case of severe tick-borne encephalitis virus associated meningoencephalitis in France: Is there a place for polyvalent intravenous immunoglobulins?

Tick-borne encephalitis virus (TBEV) is a common cause of viral encephalitis in parts of Central and Eastern Europe, with a recent resurgence of cases and geographical expansion. Active immunization results in a high rate of seroconversion and is the most effective measure to reduce the incidence of tick-borne encephalitis (TBE). In France, an endemic country, vaccination is recommended only for travelers staying in rural or forested areas in endemic regions. Polyvalent intravenous immunoglobulin (IVIG) is sometimes used as rescue treatment of viral encephalitis. However, few cases of TBEV meningoencephalitis treated with polyvalent IVIG have been described. We report here a case of autochthonous TBEV meningoencephalitis in a French patient with cranial nerve involvement that was treated with IVIG and discuss the possible mechanisms of action.

Late-Onset HSV-2 Encephalitis in a Kidney Transplant Recipient: A Rare Case Report

Infections are an important cause of morbidity and mortality in renal transplant recipients. Among the viral pathogens encountered in this population, herpes simplex virus (HSV), a member of the Alphaherpesvirinae subfamily, has an important place. HSV type 2 infections in this immunosuppressed population are primarily due to viral reactivation. While HSV-2 frequently presents as genital herpes or remains asymptomatic, in rare cases, it can lead to severe neurological manifestations, such as encephalitis, particularly in the early post-transplant period with a reported mortality rate of up to 40%. We present the case of a 49-year-old male who, three years after kidney transplantation, developed acute neurological symptoms, including aphasia and disorientation. Polymerase chain reaction (PCR) analysis of cerebrospinal fluid (CSF) identified HSV-2 as the causative pathogen, enabling a swift and accurate diagnosis. The patient was promptly treated with intravenous acyclovir, adjusted for renal function, resulting in complete neurological recovery and subsequent negative follow-up CSF PCR results. This case emphasizes the vital role of PCR diagnostics as the gold standard for confirming viral encephalitis, particularly in immunosuppressed patients, where atypical presentations can complicate diagnosis. It also highlights the importance of considering HSV-2 encephalitis in the differential diagnosis even beyond the immediate post-transplant period. Early recognition and management, facilitated by the multidisciplinary approach, are critical for improving outcomes in this vulnerable patient population.

Enterovirus and Parechovirus Neurologic Infections in Children: Clinical Presentations and Neuropathogenesis

Enteroviruses (EVs) and parechoviruses (PeVs) are common pathogens of childhood. Enteroviral infections cause a range of clinical syndromes from mild illness to neurologic manifestations of meningitis, encephalitis, and acute flaccid myelitis. Disease manifestations are driven by a combination of viral replication and host immune response. Despite ubiquitousness and clinical importance, there are no approved targeted therapies for these viruses and most are without an available vaccine. Studies of EV neuropathogenesis began with poliovirus and are ongoing for other nonpolio EVs and PeVs. Many unanswered questions remain with regard to cellular tropism, mechanisms of dissemination, receptor usage, immunologic control, and cellular death. This review describes what is known about epidemiology, clinical presentations, and neuropathogenesis of these important pathogens.

Anti-CD20 Therapy in Children With Severe Epstein-Barr Virus-Associated Meningoencephalitis

Epstein-Barr virus meningoencephalitis is a rare central nervous system infection that lacks standardized treatment. Immunocompetent and immunosuppressed individuals with this condition frequently have poor prognostic outcomes, making the need to identify therapeutic interventions high. Here, we report 2 pediatric cases of severe Epstein-Barr virus meningoencephalitis, both unresponsive to immunoglobulin and corticosteroid therapy, who demonstrated rapid clinical recovery following rituximab administration. Prognostic outcomes revealed marked improvements in symptoms, neurologic function, and quality of life. Rituximab may offer therapeutic potential in severe and refractory Epstein-Barr virus meningoencephalitis through the medication's target of Epstein-Barr virus harboring B cells. This report emphasizes the need for timely evaluation and consideration of rituximab therapy in immunocompetent pediatric patients with Epstein-Barr virus meningoencephalitis.

Fatal Fulminant Epstein-Barr Virus (EBV) Encephalitis in Immunocompetent 5.5-Year-Old Girl-A Case Report with the Review of Diagnostic and Management Dilemmas

INTRODUCTION

Epstein-Barr virus (EBV) usually causes mild, self-limiting, or asymptomatic infection in children, typically infectious mononucleosis. The severe course is more common in immunocompromised patients. Neurological complications of primary infection, reactivation of the latent infection, or immune-mediated are well-documented. However, few published cases of fatal EBV encephalitis exist. Case presentation We report a case of a 5.5-year-old immunocompetent girl with fulminant EBV encephalitis fulfilling the criteria for the recently proposed subtype Acute Fulminant Cerebral Edema: (AFCE). The child presented with fever, vomiting, altered mental status, and ataxia. Her initial brain CT (computed tomography) scan was normal. On day 2 she developed refractory status epilepticus requiring intubation, ventilation, and sedation for airway protection and seizure control. Magnetic resonance imaging (MRI) scan showed cytotoxic brain edema. Despite intensive treatment, including acyclovir, ceftriaxone, hyperosmotic therapy (3% NaCl), intravenous immunoglobulins (IVIG), corticosteroids, as well as supportive management, on day 5 she developed signs of impending herniation. Intensification of therapy (hyperventilation, deepening sedation, mannitol) was ineffective, and a CT scan demonstrated generalized brain edema with tonsillar herniation. EBV primary infection was confirmed by serology and qPCR in blood samples and post-mortem brain tissue. An autopsy was consistent with the early phase of viral encephalitis. Conclusions This case confirms that normal or non-specific CT and MRI scans do not exclude encephalitis diagnosis if clinical presentation fulfills the diagnostic criteria. The implementation of prophylactic anticonvulsants could improve outcomes. Intracranial pressure (ICP) monitoring should be considered in AFCE for better ICP management. Decompressive craniectomy might be a life-saving option in refractory cases. An encephalitis management algorithm is proposed.

Autoimmune and infectious encephalitis: development of a discriminative tool for early diagnosis and initiation of therapy

BACKGROUND

Encephalitis originates from diverse autoimmune and infectious etiologies. Diagnostic challenges arise due to the spectrum of presentation and the frequent absence of specific biomarkers. This study aimed to comprehensively characterize and differentiate autoimmune encephalitis (AE) from infectious encephalitis (IE) in adults, and disentangle clinical, paraclinical, and therapeutic differences.

METHODS

A cohort study spanning 10 years was conducted across three Austrian tertiary care hospitals. Inclusion criteria comprised adults with probable or definite encephalitis. Demographics, clinical features, technical findings, treatment modalities, and outcomes were collected from the electronic patient files. A follow-up was performed via telephone interviews and clinical visits.

RESULTS

Of 149 patients, 17% had AE, 73% IE, and 10% encephalitis of unknown etiology. Significant differences between AE and IE included the prevalence of acute symptomatic seizures (AE: 85% vs. IE: 20%, p < 0.001), fever (8% vs. 72%, p < 0.001), headache (15% vs. 61%, p < 0.001), and focal neurological deficits (56% vs. 23%, p = 0.004), respectively. Paraclinical differences comprised lower CSF pleocytosis in AE compared to IE (median 6 cells/µl vs. 125 cells/µl, p < 0.001). Epileptic discharges on EEG and MRI lesions were more prevalent in AE than IE (50% vs. 14%, p < 0.001; 50% vs. 28%, p = 0.037). The modified Rankin Scale scores at discharge and last follow-up (median duration 2304 days, IQR 1433-3274) indicated favorable outcomes in both groups.

CONCLUSION

This comprehensive analysis provides insights into the epidemiology, clinical, paraclinical, and therapeutic aspects and the outcomes of AE and IE in adults. We developed a diagnostic tool that facilitates early differentiation between AE and IE, aiding in timely therapeutic decision-making.

Opsomyoclonus: A rare complication of West Nile virus

ABSTRACT

West Nile virus is a mosquito-borne illness that usually presents as asymptomatic or with a viral syndrome, and normally is treated with supportive care or immunotherapy. However, some patients can develop neurologic symptoms of viral meningoencephalitis. This article describes a patient who developed opsomyoclonus, a rare complication of West Nile virus meningoencephalitis. She was treated with immunotherapy with no resolution of her symptoms. Symptom improvement occurred with subsequent treatment with clonazepam and dexamethasone.

Adjunctive Intravenous Immunoglobulin and Glucocorticoid Therapy in Severe Herpes Simplex Encephalitis with Excellent Outcome Begs for Larger Trials Evaluating Immunomodulatory Therapy

BACKGROUND Despite the preponderance of evidence of immune-driven pathophysiology of disease in herpes simplex virus-1 (HSV-1) encephalitis, current treatment paradigms do not officially recommend adjunctive immunomodulatory therapy in addition to acyclovir. This may in part explain the poor long-term outcomes in patients with severe HSV encephalitis. This report is of a 21-year-old man presenting with a 4-day history of nausea, headache, and fever and a diagnosis of HSV-1 encephalitis. CASE REPORT We describe the case of a young male with clinically and radiographically severe HSV-1 encephalitis diagnosed by PCR of cerebrospinal fluid (CSF), who demonstrated immediate improvement upon treatment with intravenous immunoglobulin (IVIG, 0.5 g/kg daily ×3 days) in addition to acyclovir and dexamethasone therapy. Acyclovir therapy was extended beyond 21 days due to persistently positive HSV-1 CSF PCR. He developed N-methyl-D-aspartate (NMDA) receptor antibodies at 6 weeks, but his long-term outcome far exceeded expectations. While some of his neurological deficits appear to be permanent, he is living a normal life. CONCLUSIONS Overwhelming evidence demonstrates that brain injury due to HSV encephalitis is driven by immune reactions stimulated by HSV rather than HSV itself. Nevertheless, use of immunomodulatory therapy such as glucocorticoids and IVIG are left to the discretion of individual clinicians rather than being recommended in treatment guidelines, which instead recommend acyclovir therapy. The present case highlights the potential role of immunomodulatory therapy with IVIG in HSV encephalitis and the importance of early diagnosis and treatment.

Therapeutic advances in neuroinfectious diseases

There have been several major advances in therapeutic options for the treatment of neurological infections over the past two decades. These advances encompass both the development of new antimicrobial therapies and the repurposing of existing agents for new indications. In addition, advances in our understanding of the host immune response have allowed for the development of new immunomodulatory strategies in the treatment of neurological infections. This review focuses on the key advances in the treatment of neurological infections, including viral, bacterial, fungal, and prion diseases, with a particular focus on immunomodulatory treatment options. This review also highlights the process by which clinicians can request access to therapeutic agents on a compassionate or emergency basis when they may not be commercially available. While many therapeutic advances have been achieved in the past several years, there remains a pressing need for the continued development of additional therapeutic agents in the treatment of neurological infections.

An Adolescent Presenting With Mania and Catatonia Associated With Coronavirus Disease-2019 Encephalitis

There is growing evidence that coronavirus disease-2019 (COVID-19) infection may have various neuropsychiatric manifestations and long-term outcomes. In this article, the authors report a rare case of a 16-year-old male with no previous history of psychiatric illness who presented with an acute manic episode, including laughing for no evident reason, talking to himself, isolation, irritability, sleeplessness, decreased appetite, prolonged staring episodes, having delusions about being harmed or controlled, and aggression. Despite initiating outpatient treatment with a mood stabilizer and antipsychotic for presumed bipolar disorder with psychotic features, his symptoms worsened, and he became catatonic with a decreased level of consciousness, leading to his hospitalization on day 10. Although he had not shown typical evidence of infection with COVID-19 in the days leading up to or during his hospitalization and his initial COVID-19 test was negative, his COVID-19 test was positive on day 14, and his chest X-ray showed infiltrations. His acute manic symptoms and catatonia were identified to be associated with COVID-19 encephalitis after excluding other causes. He responded well to treatment with lorazepam for catatonia and a course of intravenous immunoglobulin, methylprednisolone, and remdesivir for COVID-19 encephalitis. This case demonstrates the workup and treatment of a rare neuropsychiatric manifestation of COVID-19 encephalitis in an adolescent, which started with no past psychiatric history and no typical symptoms of COVID-19 infection.

Intravenous immunoglobulin treatment in childhood encephalitis (IgNiTE): a randomised controlled trial

OBJECTIVE

To investigate whether intravenous immunoglobulin (IVIG) improves neurological outcomes in children with encephalitis when administered early in the illness.

DESIGN

Phase 3b multicentre, double-blind, randomised placebo-controlled trial.

SETTING

Twenty-one hospitals in the UK.

PARTICIPANTS

Children aged 6 months to 16 years with a diagnosis of acute or subacute encephalitis, with a planned sample size of 308.

INTERVENTION

Two doses (1 g/kg/dose) of either IVIG or matching placebo given 24-36 hours apart, in addition to standard treatment.

MAIN OUTCOME MEASURE

The primary outcome was a 'good recovery' at 12 months after randomisation, defined as a score of≤2 on the Paediatric Glasgow Outcome Score Extended.

SECONDARY OUTCOME MEASURES

The secondary outcomes were clinical, neurological, neuroimaging and neuropsychological results, identification of the proportion of children with immune-mediated encephalitis, and IVIG safety data.

RESULTS

18 participants were recruited from 12 hospitals and randomised to receive either IVIG (n=10) or placebo (n=8) between 23 December 2015 and 26 September 2017. The study was terminated early following withdrawal of funding due to slower than anticipated recruitment, and therefore did not reach the predetermined sample size required to achieve the primary study objective; thus, the results are descriptive. At 12 months after randomisation, 9 of the 18 participants (IVIG n=5/10 (50%), placebo n=4/8 (50%)) made a good recovery and 5 participants (IVIG n=3/10 (30%), placebo n=2/8 (25%)) made a poor recovery. Three participants (IVIG n=1/10 (10%), placebo n=2/8 (25%)) had a new diagnosis of epilepsy during the study period. Two participants were found to have specific autoantibodies associated with autoimmune encephalitis. No serious adverse events were reported in participants receiving IVIG.

CONCLUSIONS

The IgNiTE (ImmunoglobuliN in the Treatment of Encephalitis) study findings support existing evidence of poor neurological outcomes in children with encephalitis. However, the study was halted prematurely and was therefore underpowered to evaluate the effect of early IVIG treatment compared with placebo in childhood encephalitis.

TRIAL REGISTRATION NUMBER

Clinical Trials.gov NCT02308982; ICRCTN registry ISRCTN15791925.

Tick-Borne Encephalitis (TBE): From Tick to Pathology

Tick-borne encephalitis (TBE) is a viral arthropod infection, endemic to large parts of Europe and Asia, and is characterised by neurological involvement, which can range from mild to severe, and in 33-60% of cases, it leads to a post-encephalitis syndrome and long-term morbidity. While TBE virus, now identified as Orthoflavivirus encephalitidis, was originally isolated in 1937, the pathogenesis of TBE is not fully appreciated with the mode of transmission (blood, tick, alimentary), viral strain, host immune response, and age, likely helping to shape the disease phenotype that we explore in this review. Importantly, the incidence of TBE is increasing, and due to global warming, its epidemiology is evolving, with new foci of transmission reported across Europe and in the UK. As such, a better understanding of the symptomatology, diagnostics, treatment, and prevention of TBE is required to inform healthcare professionals going forward, which this review addresses in detail. To this end, the need for robust national surveillance data and randomised control trial data regarding the use of various antivirals (e.g., Galidesivir and 7-deaza-2'-CMA), monoclonal antibodies, and glucocorticoids is required to improve the management and outcomes of TBE.

Tick-Borne Encephalitis Virus: A Comprehensive Review of Transmission, Pathogenesis, Epidemiology, Clinical Manifestations, Diagnosis, and Prevention

Tick-borne encephalitis virus (TBEV), a member of the Flaviviridae family, can cause serious infection of the central nervous system in humans, resulting in potential neurological complications and fatal outcomes. TBEV is primarily transmitted to humans through infected tick bites, and the viral agent circulates between ticks and animals, such as deer and small mammals. The occurrence of the infection aligns with the seasonal activity of ticks. As no specific antiviral therapy exists for TBEV infection, treatment approaches primarily focus on symptomatic relief and support. Active immunization is highly effective, especially for individuals in endemic areas. The burden of TBEV infections is increasing, posing a growing health concern. Reported incidence rates rose from 0.4 to 0.9 cases per 100,000 people between 2015 and 2020. The Baltic and Central European countries have the highest incidence, but TBE is endemic across a wide geographic area. Various factors, including social and environmental aspects, improved medical awareness, and advanced diagnostics, have contributed to the observed increase. Diagnosing TBEV infection can be challenging due to the non-specific nature of the initial symptoms and potential co-infections. Accurate diagnosis is crucial for appropriate management, prevention of complications, and effective control measures. In this comprehensive review, we summarize the molecular structure of TBEV, its transmission and circulation in natural environments, the pathogenesis of TBEV infection, the epidemiology and global distribution of the virus, associated risk factors, clinical manifestations, and diagnostic approaches. By improving understanding of these aspects, we aim to enhance knowledge and promote strategies for timely and accurate diagnosis, appropriate management, and the implementation of effective control measures against TBEV infections.

Optimizing Antiviral Dosing for HSV and CMV Treatment in Immunocompromised Patients

Herpes simplex virus (HSV) and cytomegalovirus (CMV) are DNA viruses that are common among humans. Severely immunocompromised patients are at increased risk of developing HSV or CMV disease due to a weakened immune system. Antiviral therapy can be challenging because these drugs have a narrow therapeutic window and show significant pharmacokinetic variability. Above that, immunocompromised patients have various comorbidities like impaired renal function and are exposed to polypharmacy. This scoping review discusses the current pharmacokinetic (PK) and pharmacodynamic (PD) knowledge of antiviral drugs for HSV and CMV treatment in immunocompromised patients. HSV and CMV treatment guidelines are discussed, and multiple treatment interventions are proposed: early detection of drug resistance; optimization of dose to target concentration by therapeutic drug monitoring (TDM) of nucleoside analogs; the introduction of new antiviral drugs; alternation between compounds with different toxicity profiles; and combinations of synergistic antiviral drugs. This research will also serve as guidance for future research, which should focus on prospective evaluation of the benefit of each of these interventions in randomized controlled trials.

Antibody Therapy for COVID-19: Categories, Pros, and Cons

COVID-19 is a life-threatening respiratory disease triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has been considered a pandemic viral infection since December 2019. The investigation of the effective prophylaxis or therapeutic strategies for emergency management of the current condition has become a priority for medical research centers and pharmaceutical companies. This article provides a comprehensive review of antibody therapy and its different categories with their advantages and disadvantages for COVID-19 over the last few years of the current pandemic. Antibodies can be generated by active immunization, including natural infection with a pathogen and vaccination, or by the passive immunization method such as convalescent plasma therapy (CPT) and antibody synthesis in laboratories. Each of these ways has its characteristics. Arming the immune system with antibodies is the main aim of antiviral therapeutic procedures toward SARS-CoV-2. Collecting and discussing various aspects of available data in this field can give researchers a better perspective for the production of antibody-based products or selection of the most appropriate approach of antibody therapies to improve different cases of COVID-19. Moreover, it can help them control similar viral pandemics that may happen in the future appropriately.

Epstein-Barr virus meningoencephalitis in a young immunocompetent child: A case report

Epstein-Barr virus (EBV) usually causes mild, asymptomatic, and self-recovered infections in young children. Yet, neurological involvement of this virus has been reported. EBV meningoencephalitis is relatively rare in immunocompetent children. Herein, we describe a case of 2-year-old previously healthy girl presented with high-grade fever and exudative tonsillitis. Her neurological examination showed alteration of consciousness and neck stiffness. A history of generalized tonic-clonic seizures was noted. A diagnosis of EBV meningoencephalitis was definitely confirmed by a positive result for serum viral capsid antigen IgM, and a detection of EBV DNA in cerebrospinal fluid. Her neuroimaging studies demonstrated evidence of leptomeningeal enhancements along bilateral parietal cortical sulci and around the brainstem with a hypodense lesion in the left parietal area - the typical findings of EBV meningoencephalitis. This patient was treated with intravenous corticosteroid without antiviral agents. Her clinical symptoms gradually improved. She was discharged from the hospital on the 19th day of hospitalization without neurological sequelae. Although EBV is not a primary causative agent of meningoencephalitis in immunocompetent children, it should always be considered regardless of the presence or absence of classical infectious mononucleosis symptoms. Early recognition and properly treatment are important for a good prognosis.

Antiviral treatment with fluoxetine for rituximab-associated chronic echovirus 13 meningoencephalitis and myofasciitis

BACKGROUND & PURPOSE

Enterovirus infections pose a serious threat for patients with humoral deficiencies and may be lethal, while the efficacy of proposed treatment options, such as corticosteroids, intravenous immunoglobulins and fluoxetine remain debated.

METHODS

We investigated viral clearance in a patient with rituximab-induced B-cell depletion and chronic echovirus 13 (E13) meningoencephalitis/myofasciitis in response to intravenous immunoglobulins and fluoxetine using sequential semi-quantitative E13 viral load measurements by real-time reverse transcription polymerase chain reaction. Fluoxetine concentrations in plasma and cerebrospinal fluid were determined by liquid chromatography-mass spectrometry.

RESULTS

Intravenous immunoglobulins appeared ineffective in this case of E13 infection, whereas virus clearance in cerebrospinal fluid was obtained after 167 days of oral fluoxetine. Since treatment with corticosteroids resulted in a flare of symptoms, rechallenge with viral load measurements was not attempted.

CONCLUSION

In this report of a patient with rituximab-associated chronic echovirus 13 meningoencephalitis viral clearance in response to single treatment options is assessed for the first time. Our observations further support the in vivo efficacy of fluoxetine against enteroviral infections. More research is needed to establish its efficacy in different enterovirus strains.

Neurology of Acute Viral Infections

As specialists in acute neurology, neurohospitalists are often called upon to diagnose and manage acute viral infections affecting the nervous system. In this broad review covering the neurology of several acute viral infections, our aim is to provide key diagnostic and therapeutic pearls of practical use to the busy neurohospitalist. We will review acute presentations, diagnosis, and treatment of human herpesviruses, arboviruses, enteroviruses, and some vaccine-preventable viruses. The neurological effects of coronaviruses, including COVID-19, are not covered in this review.

Enteroviral Rhombencephalitis with Abducens Nerve Palsy and Cardio-Pulmonary Failure in a 2-Year-Old Boy

Enterovirus infection is endemic in many areas, especially in Southeast Asia. Enterovirus infection with severe complications (EVSC) is life-threatening, and timely diagnosis and management are crucial for successful management. Here, we report on a 2-year-old boy with hand, foot, and mouth disease. Myoclonic jerks developed and left abducens nerve palsy followed. Brain magnetic resonance imaging (MRI) showed rhombencephalitis. Pulmonary edema and cardiopulmonary failure developed, and intravenous immunoglobulin and extracorporeal membrane oxygenation were administered. He had a tracheostomy with home ventilator use after 64 days of hospitalization. At a 5-year follow-up, his neurodevelopment was normal with complete recovery from the abducens nerve palsy. The progress of EVSC may be rapid and fulminant, and timely diagnosis is critical for patient prognosis and outcomes. The presence of abducens nerve palsy is an indicator of enteroviral rhombencephalitis, and immediate and appropriate management is suggested.

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.