Possible Toxin-Induced Acute Necrotising Encephalitis (ANE) With Secondary Vasculopathy and Paroxysmal Autonomic Instability With Dystonia (PAID) Syndrome

Acute necrotising encephalitis (ANE) is a rare and life-threatening disorder typically associated with viral pathogens triggering an inflammatory response. It is characterised by rapid neurological deterioration linked to a cytokinetic storm which radiologically manifests with cerebral radiological changes. We present a unique case not previously documented of an immunocompetent 23-year-old male who survived the course of ANE, with widespread involvement of the brain including the deep white matter, cortex, superior frontal gyrus, occipital lobe and cerebellum. His disease course was complicated by a ventilator-associated empyema, paroxysmal autonomic instability with dystonia (PAID) syndrome) and livedo reticularis which cumulatively resulted in a poor neurological outcome.

Good Outcome With Respect to Acute Necrotizing Encephalitis in Children Associated With Post-infectious SARS-CoV-2

This case report demonstrates an excellent outcome in a child with acute necrotizing encephalitis that was likely associated with the post-infectious SARS-CoV-2. The aim of this report is to emphasize that early diagnosis and initiation of immunotherapy treatment may yield good outcome, particularly with the use of tocilizumab and high-dose methylprednisolone. Post immunotherapy, significant neurological improvement was seen through the gradual improvement of Glasgow Coma Scale (GCS) score of 6 to GCS score of 12 within three weeks and subsequently acquired almost full neurological function with minimally dependent activity of daily living (ADL) at eight weeks in the post-treatment follow-up. It is interesting to identify that the possible causative factor could be the natural infection in a vaccinated patient. This was evidenced by the persistently high SARS-CoV-2 immunoglobulin G (IgG)-Spike antibodies titre in a patient vaccinated with two doses of BNT162b2, 11 months before presentation.

Human Herpesvirus-6 Encephalitis Associated With Acute Necrotizing Encephalopathy in an Immunocompetent Child: A Case Report and Literature Review

Human herpesvirus type 6 (HHV-6) is a DNA virus considered a member of the Herpesviridae family. HHV-6 is acquired early in life, when it may cause roseola infantum and nonspecific febrile illnesses which is usually a self-limiting disease before the age of two. Primary HHV-6 encephalitis and acute necrotizing encephalopathy (ANE) are rare diseases to occur in immunocompetent children. We describe an unusual case of HHV-6 encephalitis with mixed features of acute necrotizing encephalopathy and acute disseminated encephalomyelitis and contextualize it with a review of the literature on HHV-6 encephalitis in immunocompetent children. Although the incidence of primary HHV-6 encephalitis is rare in immunocompetent children, HHV-6 encephalitis associated with acute necrotizing encephalopathy is a devastating disease, highly fatal and neurologically damaging disease. Therefore, early testing and diagnosis are crucial as well as effective management of encephalitis with antiviral therapy is highly recommended.

Acute Necrotizing Encephalitis Due to Influenza B in a Child: A Case Report

Acute necrotizing encephalitis (ANE) is a rare and life-threatening form of encephalitis associated with influenza virus and other pathogens. It is characterized by a rapid onset of neurological symptoms and has been linked to a cytokine storm within the brain. We present a unique case of an eight-year-old female with influenza B-associated ANE, involving multiple brain areas including the cerebellum and brainstem and cauda equina involvement. The patient had a rapid neurological deterioration, and MRI findings revealed extensive multifocal areas of abnormal brain parenchyma and inflammation with Guillain-Barre appearance in the cauda equina. To the best of our knowledge, this is the first reported case of ANE with cauda equina involvement leading to neurological deficits. Despite treatment with oseltamivir, steroids, and intravenous immunoglobulins, the patient had poor neurological outcomes, similar to those reported in the literature.

Central neuroinflammation in Covid-19: a systematic review of 182 cases with encephalitis, acute disseminated encephalomyelitis, and necrotizing encephalopathies

Growing evidence demonstrates the association of encephalitis, meningoencephalitis or encephalomyelitis, with SARS-CoV-2 infection. This study aims to determine the profile and possible mechanisms behind CNS inflammatory diseases in the context of Covid-19. We conducted a systematic review of case reports on Covid-19-related encephalitis, meningoencephalitis, acute necrotizing encephalitis, and acute disseminated encephalomyelitis in adults, published before January 2021. A total of 182 cases (encephalitis = 109, meningoencephalitis = 26, acute disseminated encephalomyelitis = 35, acute necrotizing (hemorrhagic) encephalitis = 12) were included. While cerebrospinal fluid (CSF) pleocytosis and increased protein level was present in less than 50%, magnetic resonance imaging (MRI) and electroencephalogram (EEG) were abnormal in 78 and 93.2% of all cases, respectively. Viral particles were detected in cerebrospinal fluid of only 13 patients and autoantibodies were present in seven patients. All patients presented with altered mental status, either in the form of impaired consciousness or psychological/cognitive decline. Seizure, cranial nerve signs, motor, and reflex abnormalities were among associated symptoms. Covid-19-associated encephalitis presents with a distinctive profile requiring thorough diagnosis and thereby a comprehensive knowledge of the disease. The clinical profile of brain inflammation in Covid-19 exhibits majority of abnormal imaging and electroencephalography findings with mild/moderate pleocytosis or proteinorrhachia as prevalent as normal cerebrospinal fluid (CSF). Oligoclonal bands and autoantibody assessments are useful in further evaluating neuro-covid patients, as supported by our pooled evidence. Despite the possibility that direct viral invasion cannot be easily estimated, it is still more likely that immune-mediated or autoimmune reactions play a more important role in SARS-CoV-2 neuroinflammation.

Acute Necrotizing Encephalopathy Associated With SARS-CoV-2 Exposure in a Pediatric Patient

We present the case of a nine-month-old male child with three days of fever, irritability, left focal seizure, and febrile focal status epilepticus. He had no history of previous comorbidities. A lumbar puncture was performed, which showed cerebrospinal fluid (CSF) leukocytosis; protein and glucose were normal, and the polymerase chain reaction (PCR) panel for 14 pathogens in CSF was negative. Immunoglobulin G (IgG) qualitative and quantitative tests were positive for coronavirus disease 2019 (COVID-19) upon arrival. An MRI performed one week after the initial onset showed findings suggestive of acute necrotizing encephalopathy (ANE). The patient required mechanical ventilation. However, his symptoms did not improve and follow-up imaging two weeks later showed progression of the disease with hemorrhagic changes. To our knowledge, this is the first reported case of ANE associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-​2) infection in a pediatric patient.

[Influenza-associated acute necrotizing encephalitis in an adult]

A rare case of acute necrotizing encephalitis associated with influenza virus in an adult man is described. This clinical case is one of the few published cases in the world literature and the only one in the Russian literature.

Acute Necrotizing Encephalitis in Viral Respiratory Tract Infection: An Autopsy Case Report

Acute necrotizing encephalitis (ANE) is a rare complication of viral respiratory tract infections, with specific histological changes. The condition is most commonly described in the pediatric population, however, it can also develop in the elderly, with some genetic factors being described as contributory. Herein, we report the autopsy finding of a patient with a viral respiratory tract infection, complicated with ANE. The patient was a 77-year-old female with multiple comorbidities living in a social home. For the two months prior, she had been hospitalized with cerebral infarction, respiratory tract infection, and exacerbation of chronic cardiac failure and concomitant hypertension and type 2 diabetes. On gross examination, the brain was edematous, with ground-glass opacity meninges a focus of encephalomalacia in the right cerebral hemisphere and multiple petechial hemorrhages. Histology revealed diffuse foci of encephalitis, with large areas of neuronal necrosis (coagulative-like necrosis) around the blood vessels and a sharp border with the surrounding healthy parenchyma - ANE. The patients tested negative for coronavirus disease 2019 (COVID-19).

[Influenza - associated acute necrotizing encephalitis in adults]

The authors describe a rare clinical case of non-fatal acute necrotizing encephalitis associated with influenza virus in an adult man. This clinical case is one of the few cases published in the world literature and the only one in the Russian literature.

Influenza-Associated Acute Necrotizing Encephalopathy in Siblings

Encephalopathy is an important complication associated with influenza, most frequently observed in young children, with a wide range of severity. The most severe category of influenza-associated encephalopathy (IAE) is acute necrotizing encephalopathy (ANE), characterized by high frequency of neurologic sequelae and fatal outcomes. We report two young siblings who developed fever and seizures with altered mental status. Influenza A(H1N1)pdm09 virus infection was identified in upper respiratory tract specimens from both patients, and neuroimaging revealed bilateral inflammatory lesions, consistent with acute necrotizing encephalopathy. Neither child had received influenza vaccination. Both children progressed to critical illness and required invasive mechanical ventilation. In addition to critical care management, both patients received high-dose corticosteroids, mannitol, anticonvulsants, and antiviral treatment of influenza. The older child recovered fully and was discharged 2 weeks after illness onset, but the younger sibling developed severe brainstem edema and cerebellar tonsillar herniation, and died on illness day 11. Both children tested positive for Ran Binding Protein 2 (RANBP2) gene mutations. RANBP2 is a genetic polymorphism associated with recurrent episodes of necrotizing encephalitis with respiratory viral infections. Annual influenza vaccination is especially important for ANE survivors, with or without RANBP2 mutations, their household contacts, and caregivers. During influenza season, close monitoring of any child with a history of neurological complications associated with respiratory illness is indicated, with prompt initiation of antiviral treatment with onset of acute respiratory illness, and influenza testing performed by molecular assay.

Successful Treatment of Influenza-Associated Acute Necrotizing Encephalitis in an Adult Using High-Dose Oseltamivir and Methylprednisolone: Case Report and Literature Review

A case of influenza-associated acute necrotizing encephalitis (ANE) is described in an otherwise healthy adult. The patient was treated successfully with a combination of high-dose methylprednisolone and high-dose oseltamivir. The patient relapsed after discontinuing 150 mg twice daily oseltamivir but quickly improved and eventually recovered after reinitiation of high-dose oseltamivir for an additional 2 weeks. The clinical presentation, pathogenesis, and treatment of influenza-associated ANE is reviewed. The use of high-dose oseltamivir in combination with methylprednisolone may offer additional therapeutic benefit for this rare and poorly understood complication of influenza infection.

Successful Treatment of Influenza-Associated Acute Necrotizing Encephalitis in an Adult Using High-Dose Oseltamivir and Methylprednisolone: Case Report and Literature Review

A case of influenza-associated acute necrotizing encephalitis (ANE) is described in an otherwise healthy adult. The patient was treated successfully with a combination of high-dose methylprednisolone and high-dose oseltamivir. The patient relapsed after discontinuing 150 mg twice daily oseltamivir but quickly improved and eventually recovered after reinitiation of high-dose oseltamivir for an additional 2 weeks. The clinical presentation, pathogenesis, and treatment of influenza-associated ANE is reviewed. The use of high-dose oseltamivir in combination with methylprednisolone may offer additional therapeutic benefit for this rare and poorly understood complication of influenza infection.