A case report and literature review on tocilizumab-cured acute necrotizing encephalopathy caused by influenza A virus

Introduction

Acute Necrotizing Encephalopathy (ANE), is a kind of severe Central Nervous System Disease. The commonest pathogen is the influenza virus. The pathogenesis of ANE is bound up to genetic susceptibility and cytokine storm. Interleukin-6 (IL-6) is deemed as the core function in cytokine storm of ANE and that plays a significant role in evaluating the severity of Influenza-Related ANE. Tocilizumab, an IL-6 antagonist, is known to be safe and effective in the treatment of ANE when used early and has an essential role in improving prognosis and preventing disability.

Case report

This case reports a 2 year 10 month old boy who developed ANE after being infected with influenza A virus (H1N1-2019). After treatment with Tocilizumab, the child's consciousness was clear, no convulsions occurred, the movement of limbs was improved, and the lesions of encephalopathy were significantly reduced.

Conclusion

The early use of Tocilizumab is safe and effective for the treatment of ANE caused by influenza virus.

A Rare Case of Acute Necrotizing Encephalopathy of Childhood: A Case Report

Acute necrotizing encephalopathy of childhood (ANEC) is a severe neurological disorder characterized by rapid-onset encephalopathy, often associated with viral infections. Acute necrotizing encephalopathy of childhood is associated with a very high mortality rate, and survivors may face long-term neurological sequelae. Acute necrotizing encephalopathy of childhood needs to be differentiated from its closest differential diagnosis, acute disseminated encephalomyelitis (ADEM). Most of the patients with ADEM recover, with a few of them having residual neurological deficits. We present a case of an eight-year-old boy with an acute history of fever, febrile seizures, and drowsiness. Magnetic resonance imaging revealed a symmetric tricolor appearance of bilateral thalamic lesions, characteristic of ANEC.

Clinical characteristics of 4,520 paediatric patients infected with the SARS-CoV-2 omicron variant, in Xi'an, China

Background and objective

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has broad tissue tropism and high transmission, which are likely to perpetuate the pandemic. The study aim to analyze the clinicopathogenic characteristics in paediatric patients.

Methods

In this single-centre study, we retrospectively included all confirmed cases infected by SARS-CoV-2 infection at Xi'an Children's Hospital, China, from 1 December to 31 December 2022. The demographic, clinical, laboratory, and radiological features of the patients were analysed.

Results

A total of 4,520 paediatric patients with SARS-CoV-2 omicron variant infections were included. Of these, 3,861 (85.36%) were outpatients, 659 (14.64%) were hospitalised patients, and nine patients (0.20%) died. Of the nine patients who died, five were diagnosed with acute necrotising encephalopathy (ANE). The most common symptoms were fever in 4,275 (94.59%) patients, cough in 1,320 (29.20%) patients, convulsions in 610 (13.50%) patients, vomiting in 410 (9.07%) patients, runny nose/coryza in 277 (6.13%) patients, hoarseness of voice in 273 (6.04%) patients. A blood cell analysis showed a slight elevation of monocytes (mean: 11.14 ± 0.07%). The main diagnoses for both outpatients and inpatients were respiratory infection with multisystem manifestations.

Conclusions

A high incidence of convulsions is a typical characteristic of children infected with SARS-CoV-2. Five of the nine COVID-19 fatalities were associated with ANE. This indicates that nervous system damage in children with SARS-CoV-2 infection is more significant.

A Case of Acute Necrotizing Encephalopathy With Multiple Organ Failure Following COVID-19

Neurological complications are frequent non-respiratory complications associated with coronavirus disease 2019 (COVID-19), and acute encephalopathy (AE) has been reported to occur in 2.2% of patients. Among many phenotypes of AEs, acute necrotizing encephalopathy (ANE) is associated with multiple organ failure (MOF), leading to severe neurological morbidity and mortality. A previously healthy seven-year-old girl presented with a one-day history of fever followed by 12 hours of vomiting and altered consciousness. On arrival, the patient was in shock. Blood tests revealed severe acute liver failure and kidney injury, accompanied by coagulopathy. The serum interleukin-6 levels were also elevated. PCR testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was positive. A head CT scan showed heterogeneous low-density areas in the bilateral thalamus, without brainstem involvement. She was diagnosed as ANE complicated with MOF (ANE severity score = 6). Intravenous methylprednisolone and therapeutic plasma exchange (TPE) were initiated with neurocritical care. After the introduction of TPE, hemodynamics improved rapidly, followed by gradual improvement in neurological manifestations. Upon follow-up after two months, no neurological or systemic sequelae were noted. Although further studies are needed, our case suggests that early immunomodulatory therapy and TPE may have contributed to the improvement in ANE and MOF associated with COVID-19.

The youngest infant with COVID-19-associated necrotizing encephalitis in Asia: A case report

Acute necrotic encephalopathy in children is a very rare complication of severe acute respiratory syndrome coronavirus 2 infection and has rarely been reported worldwide. A 45-day-old girl was admitted to our hospital with fever and listlessness. A nose swab tested positive for the novel coronavirus nucleic acid, and her cerebrospinal fluid was positive for severe acute respiratory syndrome coronavirus 2. An early head magnetic resonance imaging scan indicated multiple abnormal signals in her bilateral cerebral hemispheres, and encephalitis was diagnosed. Twenty-three days after hospitalization, bilateral cerebral atrophy-like changes were observed on magnetic resonance imaging, with multiple softening lesions in the bilateral cerebral hemispheres, accompanied by convulsions. She was admitted to the hospital for mechanically assisted ventilation, and her condition improved after treatment of her symptoms with antiepileptic medication, anti-infection drugs, glucocorticoids, and immunoglobulins. Acute necrotic encephalopathy associated with severe acute respiratory syndrome coronavirus 2 infection in children should be detected and treated as early as possible. Satisfactory short-term efficacy can be obtained, but long-term neurological sequelae often linger.

Rapid and inexpensive bedside diagnosis of RAN binding protein 2-associated acute necrotizing encephalopathy

Acute necrotizing encephalopathy 1 (ANE1) is a very rare disorder associated with a dominant heterozygous mutation in the RANBP2 (RAN binding protein 2) gene. ANE1 is frequently triggered by a febrile infection and characterized by serious and irreversible neurological damage. Although only a few hundred cases have been reported, mutations in RANBP2 are only partially penetrant and can occur de novo, suggesting that their frequency may be higher in some populations. Genetic diagnosis is a lengthy process, potentially delaying definitive diagnosis. We therefore developed a rapid bedside qPCR-based tool for early diagnosis and screening of ANE1 mutations. Primers were designed to specifically assess RANBP2 and not RGPD (RANBP2 and GCC2 protein domains) and discriminate between wild-type or mutant RANBP2. Nasal epithelial cells were obtained from two individuals with known RANBP2 mutations and two healthy control individuals. RANBP2-specific reverse transcription followed by allele-specific primer qPCR amplification confirmed the specific detection of heterozygously expressed mutant RANBP2 in the ANE1 samples. This study demonstrates that allele-specific qPCR can be used as a rapid and inexpensive diagnostic tool for ANE1 using preexisting equipment at local hospitals. It can also be used to screen non-hospitalized family members and at risk-population to better establish the frequency of non-ANE-associated RANBP2 mutations, as well as possible tissue-dependent expression patterns.

Systematic review registration

The protocol was registered in the international prospective register of systematic reviews (PROSPERO- CRD42023443257).

Acute Necrotizing Encephalopathy in Adult Patients With COVID-19: A Systematic Review of Case Reports and Case Series

BACKGROUND AND PURPOSE

Acute necrotizing encephalopathy (ANE) is a rare neurological disorder that is often associated with viral infections. Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a few COVID-19-associated ANE cases have been reported. Since very little is known about ANE, the present study aimed to determine the clinical, biochemical, and radiological characteristics of affected patients.

METHODS

A search was conducted on PubMed, Scopus, Embase, and Web of Science databases for articles published up to August 30, 2022 using relevant keywords. Case reports and series in the English language that reported ANE in adult patients with COVID-19 confirmed by reverse transcription polymerase chain reaction were included in this study. Data on the demographic, clinical, laboratory, and radiological characteristics of patients were extracted and analyzed using the SPSS software (version 26).

RESULTS

The study included 30 patients (18 males) with COVID-19 and ANE who were aged 49.87±18.68 years (mean±standard deviation). Fever was the most-prevalent symptom at presentation (66.7%). Elevated C-reactive protein was observed in the laboratory assessments of 13 patients. Computed tomography and magnetic resonance imaging were the most-common radiological modalities used for brain assessments. The most commonly prescribed medications were methylprednisolone (30%) and remdesivir (26.7%). Sixteen patients died prior to discharge.

CONCLUSIONS

The diagnosis of COVID-19-associated ANE requires a thorough knowledge of the disease. Since the clinical presentations of ANE are neither sensitive nor specific, further laboratory and brain radiological evaluations will be needed to confirm the diagnosis. The suspicion of ANE should be raised among patients with COVID-19 who present with progressive neurological symptoms.

Case report: Presentations and cytokine profiles of inflammatory non-pulmonary COVID-19 and related diseases in children

The coronavirus disease 2019 (COVID-19) pandemic has evolved to dynamic waves of different SARS-CoV-2 variants. Initially, children diagnosed with COVID-19 presented pulmonary involvement characterized by mild diseases. In the later waves of the COVID-19 pandemic, life-threatening non-pulmonary inflammatory diseases such as (1) aseptic meningoencephalitis (ME), (2) acute necrotizing encephalopathies (ANE), and (3) multisystem inflammatory syndrome in children (MIS-C) have been reported, affecting the pediatric population. To alert timely identification and prevention of the life-threatening non-pulmonary COVID-19, we present the cases of ME, ANE, and MIS-C in terms of clinical manifestation, cytokine profile, and follow-up consequences. Based on the immunopathogenesis and risk factors associated with non-pulmonary COVID-19, we delineate strategies for an early diagnosis and treatment to reduce morbidity and mortality in children.

Case report: Acute necrotizing encephalopathy: a report of a favorable outcome and systematic meta-analysis of outcomes with different immunosuppressive therapies

Acute Necrotizing Encephalopathy (ANE) is a condition characterized by symmetric, bilateral lesions affecting the thalamus and potentially other areas of the brain following an acute febrile illness. It manifests clinically as abrupt development of encephalopathy, or alteration in mental status that often includes development of seizures and progression to coma. Treatment strategies combine immunosuppressive therapies and supportive care with varying levels of recovery, however there are no universally accepted, data-driven, treatment algorithms for ANE. We first report a case of a previously healthy 10-year-old female with acute onset diplopia, visual hallucinations, lethargy, and seizures in the setting of subacute non-specific viral symptoms and found to have bilateral thalamic and brainstem lesions on MRI consistent with ANE. She was treated with a combination of immunomodulatory therapies and ultimately had a good outcome. Next, we present a meta-analysis of 10 articles with a total of 158 patients meeting clinical and radiographic criteria for ANE. Each article reported immunosuppressive treatments received, and associated morbidity or mortality outcome for each individual patient. Through our analysis, we confirm the effectiveness of high-dose, intravenous, methylprednisolone (HD-IV-MP) therapy implemented early in the disease course (initiation within 24 h of neurologic symptom onset). There was no significant difference between patients treated with and without intravenous immunoglobulin (IVIG). There was no benefit of combining IVIG with early HD-IV-MP. There is weak evidence suggesting a benefit of IL-6 inhibitor tocilizumab, especially when used in combination with early HD-IV-MP, though this analysis was limited by sample size. Finally, plasma exchange (PLEX) improved survival. We hope this meta-analysis will be useful for clinicians making treatment decisions for patients with this potentially devastating condition.

Neuroimaging in acute infection-triggered encephalopathy syndromes

Acute encephalopathy associated with infectious diseases occurs frequently in Japanese children (400-700 children/year) and is the most common in infants aged 0-3 years. Acute encephalopathy is classified into several clinicoradiological syndromes; acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is the most common subtype, followed by clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) and acute necrotizing encephalopathy (ANE). Neuroimaging, especially magnetic resonance imaging (MRI), is useful for the diagnosis, assessment of treatment efficacy, and evaluation of the pathophysiology of encephalopathy syndromes. MRI findings essential for diagnosis include delayed subcortical reduced diffusion (bright tree appearance) for AESD, reversible splenial lesions with homogeneously reduced diffusion for MERS, and symmetric hemorrhagic thalamic lesions for ANE. We reviewed several MRI techniques that have been applied in recent years, including diffusion-weighted imaging for the characterization of cerebral edema, arterial spin labeling for evaluating cerebral perfusion, and magnetic resonance spectroscopy for evaluating metabolic abnormality.

Association of IL6 and IL10 gene promotor polymorphisms with susceptibility to acute necrotizing encephalopathy

Objective

Acute necrotizing encephalopathy (ANE) is a severe complication of infectious diseases affecting the brain and systemic organs. The main pathogenesis is cytokine storm, in which interleukin-6 (IL-6) and interleukin-10 (IL-10) are candidates for key cytokines. To further elucidate their roles in the etiology and pathogenesis of ANE, we studied polymorphisms in the promotor regions of the IL6 and IL10 genes by genetic and functional analyses.

Methods

We first conducted a case-control association study of four IL6 and three IL10 polymorphisms. We genotyped 31 Japanese ANE cases and compared the results with those of approximately 200 Japanese controls. For the two polymorphisms showing a possible association, we next studied whether the polymorphisms alter the production of IL-6 or IL-10 by lymphoblasts upon phorbol 12-myristate 13-acetate (PMA) stimulation.

Results

The frequencies of IL6 rs1800796G allele and IL10 rs1800871/rs1800872 CC/CC diplotype were significantly higher in ANE cases than in controls. The IL10 CC/CC diplotype was associated with low IL-10 production, whereas the IL6 GG genotype was not associated with IL-6 production.

Conclusion

IL10 rs1800871/rs1800872 CC/CC diplotype may predispose Japanese children to ANE by altering IL-10 production in the early phase of infection. Etio-pathogenetic significance of IL6 rs1800796G remains to be elucidated.

Acute necrotizing encephalopathy in children with COVID-19: a retrospective study of 12 cases

Background

Acute necrotizing encephalopathy (ANE) is a devastating neurologic condition that can arise following a variety of systemic infections, including influenza and SARS-Cov-2. The clinical features of COVID-19-associated ANE in pediatric patients based on multi-case data have not yet been described and remain obscure. We reviewed 12 pediatric patients to better describe the clinical features of ANE with COVID-19.

Methods

We retrospectively collected and summarized the clinical features of ANE in children with COVID-19. Clinical data were collected from 12 children, including their general status, clinical symptoms, laboratory tests, and neuroimaging features.

Results

Among the subjects, 10 were over 5 years old and they accounted for 83.33%. A large percentage of those affected (66.67%) were females. The major manifestations included fever (100%), impaired consciousness (100%), and convulsions (75%). We determined that increased interleukin (IL)-6 and IL-10, and tumor necrosis factor-α and interferon gamma were not predictive of severe ANE and mortality in children with COVID-19 in this study. All children presented with abnormal neuroimaging with multiple and symmetrically distributed lesions, involving the thalamus, basal ganglia, cerebellum, and brain hemispheres. Eight of the 12 children died, resulting in a mortality rate of 66.67%, and 75% of these children were females. Importantly, we found the timely administration of mannitol after an acute onset of convulsions or disturbance of consciousness may be decreased the high mortality induced by ANE children with COVID-19.

Conclusion

COVID-19 associated with ANE in children is characterized by sudden symptom onset, rapid disease progression, and high mortality.

Coronavirus or Cholangitis? An Acute Necrotizing Encephalopathy Caused by COVID-19

A 63-year-old Japanese woman presented to the emergency room with a fever and altered mental status. She was diagnosed as acute cholangitis and coronavirus disease 2019 (COVID-19). On the second day, her consciousness level deteriorated. The patient was finally diagnosed with acute necrotizing encephalopathy (ANE). This case illustrated ANE caused by COVID-19 that co-occurred with acute cholangitis. ANE is a subtype of acute encephalitis/encephalopathy, sometimes related to COVID-19. ANE shares some clinical features with acute cholangitis. COVID-19 and bacterial infections may coexist, thus complicating an accurate diagnosis. Physicians should avoid overlooking life-threatening febrile conditions even if the diagnosis of COVID-19 is confirmed.

Pathogenesis and Management of Acute Necrotizing Encephalopathy

INTRODUCTION

During the COVID-19 pandemic, many cases of acute necrotizing encephalopathy (ANE) secondary to COVID-19 have been reported. ANE is characterized by a rapid onset, a fulminant course, and low morbidity and fatality rates. Therefore, clinicians need to be vigilant for such disorders, especially during the influenza virus and COVID-19 epidemics.

AREAS COVERED

The authors summarize the most recent studies on the clinical spectrum and treatment essentials of ANE to provide references for prompt diagnosis and improved treatment of this rare but fatal disease.

EXPERT OPINION

ANE is a type of necrotizing lesion of the brain parenchyma. There are two major types of reported cases. One is isolated and sporadic ANE, which is primarily caused by viral infections, particularly influenza and HHV-6 virus. The other type is familial recurrent ANE, which is caused by RANBP2 gene mutations. ANE patients have rapid progression and a very poor prognosis, with acute brain dysfunction occurring within days of viral infection and requiring admission to the intensive care unit. Clinicians still need to investigate and find solutions for the problems of early detection and treatment of ANE.

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.

De novo RANBP2 variant in a fetal demise case with cerebral intraparenchymal hemorrhage

Fetal intracranial hemorrhage (ICH) may result from a wide array of causes, either associated with maternal or fetal risk factors. In the last decade, monogenic causes of susceptibility to fetal ICH have been described, in particular in association with COL4A1 and COL4A2 genes. A peculiar form of ICH is acute necrotizing encephalitis (ANE), which is characterized by a rapid-onset severe encephalopathy following an abnormal inflammatory response to an otherwise banal infection. It usually affects healthy children and it is thought to be multifactorial, with a genetic predisposition. RANBP2 gene has been extensively associated with ANE susceptibility. We hereby present a unique case of a 42-year-old secundigravida with intrauterine fetal demise at 35 weeks of gestation. Trio-based whole-exome sequencing performed on both parents and fetal DNA showed a de novo likely pathogenic variant in the RANBP2 gene on 2q13. At the fetal autopsy, subtentorial hematoma and cerebral intraparenchymal hemorrhage were present. We speculate that this might be a new phenotypic presentation of RANBP2-associated disease. However, more similar fetal cases need to be reported in order to reinforce this hypothesis.

Clinical features and imaging manifestations of acute necrotizing encephalopathy in children

PURPOSE

We summarized the clinical features of acute necrotizing encephalopathy (ANE) in children.

METHODS

Clinical data of 14 children with ANE at one center from January 2017 to January 2020 were retrospectively analyzed. ANE severity score (ANE-ss) was used to assess ANE severity, and the Glasgow Outcome Scale-Extended was used to assess functional outcomes.

RESULTS

Peak incidence was between 1 and 3 years of age (71%), and a large percentage of males were affected (79%). The main manifestations included fever (100%), seizure (86%), and impaired consciousness (100%). Seven patients (58%) developed status epilepticus. The etiology was identified in 10 patients (71%) and mainly included H1N1 (36%) and Epstein-Barr virus (29%).Complications included multiple organ failure (MOF), predominantly liver (36%), heart (21%) and kidney (7%) failure, gastrointestinal hemorrhage (21%), hypernatremia (7%), hematuria (7%), disseminated intravascular coagulation (7%), and shock (7%). Pleocytosis was observed in two patients, and increased cerebrospinal fluid protein was found in 11 patients. A missense mutation in RANBP2 (c.1754C>T: p.Thr585Met) was observed in one patient. Magnetic resonance imaging revealed increased T2 and T1 signal density in multifocal and symmetric brain lesions (bilateral thalami, 100%) in all patients during the acute phase. There were no deaths. Nine children retained neurological sequelae affecting movement, cognition, speech, vision, and/or seizure. Four children recovered almost completely. There was a significant correlation between risk classification and outcome by ANE-ss.

CONCLUSION

ANE is a group of clinical and imaging syndromes. Most patients have severe neurological sequelae, and ANE may have lower mortality. And ANE-ss can assess prognosis.

Case Report: Acute Necrotizing Encephalopathy Following COVID-19 Vaccine

Objectives

Acute necrotizing encephalopathy (ANE) is a rare neurological disorder arising from a para- or post-infectious "cytokine storm. "It has recently been reported in association with coronavirus disease 2019 (COVID-19) infection.

Methods

A 56-year-old male with a diagnosis of ANE 48 h following the first dose of ChAdOx1 nCoV-19 vaccination was investigated. Cytokine analyses on serum and cerebrospinal fluid (CSF) were performed. The patient was treated with high-dose corticosteroids and followed clinically and radiologically.

Results

Favorable clinical and radiological outcomes were noted. There was an upregulation in serum levels of CXCL5, CXCL1, Il-8, IL-15, CCL2, TGF-B, and EGF, and up-regulation in CSF levels of CXCL5, IL-2, IL-3, and IL-8.

Discussion

As COVID-19 infection has been previously reported as a possible rare cause of ANE, we speculate on an aberrant immune response mechanism that was brought about by the vaccine. To increase our understanding of the pathogenesis of ANE in the context of COVID-19 vaccination and to better define its clinical features and outcomes, clinicians and scientists should continue reporting convincing cases of such entities.

Early High-Dose Methylprednisolone Therapy Is Associated with Better Outcomes in Children with Acute Necrotizing Encephalopathy

BACKGROUND

The neurologic outcomes of acute necrotizing encephalopathy (ANE) are very poor, with a mortality rate of up to 40% and fewer than 10% of patients surviving without neurologic deficits. Steroid and immunoglobulin treatments have been the most commonly used options for ANE, but their therapeutic efficacy is still controversial.

METHOD

We retrospectively reviewed the medical records of 26 children diagnosed with ANE. We also divided these patients into two groups: 21 patients with brainstem involvement and 8 patients without brainstem involvement. Pulse steroid therapy (methylprednisolone at 30 mg/kg/day for 3 days) and intravenous immunoglobulin (2 g/kg for 2-5 days) were administered to treat ANE.

RESULTS

The overall mortality rate was 42.3%, and patients who did not survive had significantly higher initial lactate and serum ferritin levels, as well as higher rates of inotropic agent use with brainstem involvement. There were no significant differences in the outcomes of pulse steroid therapy or pulse steroid plus immunoglobulin between survivors and non-survivors. When analyzing the time between symptom onset and usage of pulse steroid therapy, pulse steroid therapy used within 24 h after the onset of ANE resulted in significantly better outcomes (p = 0.039). In patients with brainstem involvement, the outcome was not correlated with pulse steroid therapy, early pulse steroid therapy, or pulse steroid therapy combined with immunoglobulin. All patients without brainstem involvement received "early pulse methylprednisolone" therapy, and 87.5% (7/8) of these patients had a good neurologic outcome.

CONCLUSION

Pulse steroid therapy (methylprednisolone at 30 mg/kg/day for 3 days) administered within 24 h after the onset of ANE may be correlated with a good prognosis. Further studies are needed to establish a consensus guideline for this fulminant disease.

Clinical evaluation of acute necrotizing encephalopathy in children

OBJECTIVE

Acute necrotizing encephalopathy (ANE) is a rare but severe encephalopathy and is associated with a high morbidity and mortality. We aimed to analyze and compare the clinical features and predictive indicators of pediatric ANE.

MATERIALS AND METHODS

This retrospective study included children with ANE diagnosed at Guangzhou Women and Children's Medical Center between November 2018 and January 2020. Pediatric patients' information, including clinical characteristics, laboratory tests, neuroelectrophysiology and brain magnetic resonance imaging (MRI) findings, MRI score, brainstem auditory evoked potential (BAEP) grades, ANE severity scores (ANE-SS), and modified Rankin scale (mRS), were collected.

RESULTS

Twelve ANE patients were included. Among them, one patient (8.3%) died from brainstem dysfunction, one (8.3%) recovered and 10 (83.3%) experienced neurological sequelae. All patients had an initial viral infection and neurological symptoms such as acute disturbance of consciousness (ADOC) or seizure, and the interval from onset of the disease to neurological manifestations was 3 (1.25-3) days. MRI score-I ranged from 1 to 3 (1.8 ± 0.7), MRI score-II ranged from 1 to 4 (2.5 ± 1.1). ANE-SS varied from 1 to 6 (3.9 ± 1.3). The scores of mRS were from 0 to 6 (2.9 ± 1.7). Higher MRI score were associated with worse outcomes, while the BAEP grade and ANE-SS score were not significantly associated with mRS.

CONCLUSION

ANE is a severe encephalopathy syndrome with rapid progression, resulting in serious neurological sequelae. Compared with BAEP grade and ANE-SS, brain MRI shows more comprehensive advantages in predicting the prognosis of ANE patients. More in-depth research and better indicators are still needed to support the evaluation and treatment of ANE.

[A clinical study of influenza A virus infection with neurological symptoms in children]

OBJECTIVE

To study the clinical features of children with influenza A virus infection and neurological symptoms.

METHODS

A retrospective analysis was performed for the clinical data of children with laboratory-confirmed influenza A and neurological symptoms who were treated in Xi'an Children's Hospital Affiliated to Xi'an Jiaotong University from January to December, 2019.

RESULTS

A total of 895 children were diagnosed with influenza A, among whom 291 had neurological symptoms. Boys had a significantly higher incidence rate of influenza A than girls (P < 0.05), and the children aged 1-3 years had a significantly higher incidence rate than the other age groups (P < 0.05). Common neurological symptoms included seizures (97.3%), vomiting (24.1%), and headache (7.2%). Febrile seizures were the most common type of seizures, accounting for 88%. There was no significant difference in the time from disease onset to seizures and frequency seizures between the children with a history of febrile seizures and those without such history (P > 0.05). Of all the children, 3 were diagnosed with acute necrotizing encephalopathy (ANE), all of whom were girls and suffered seizures; the time from the first seizures to the occurrence of disturbance of consciousness was 0-7 hours, and 2 girls died within 2 days after disease onset. All children, except 2 who died of ANE and 1 with neurological sequelae, were cured.

CONCLUSIONS

There is a high incidence rate of neurological symptoms in children with influenza A, and seizures are the most common symptom. Most of the patients with neurological symptoms tend to have a good prognosis, but those with ANE may have a poor prognosis.

Acute Necrotizing Encephalopathy in a Four-Year-Old Boy

Acute necrotizing encephalopathy is a devastating clinico-radiological syndrome characterized by fulminant neurological deterioration after an antecedent febrile illness, as well as the imaging hallmark of bilateral thalamic involvement. Herein, we describe a 4-year-old boy with typical clinical and neuroimaging features of acute necrotizing encephalopathy. The bithalamic swelling led to a block of cerebrospinal fluid circulation at the foramen of Monro, thereby causing the mild dilatation of lateral ventricles. The periventricular areas could, therefore, have been potentially affected by the acute necrotizing encephalopathy per se and/or transependymal edema secondary to obstructive hydrocephalus. The information from diffusion imaging allows for differentiation between these two pathophysiological processes.

The Novel Coronavirus Infection (COVID-19) and Nervous System Involvement: Mechanisms of Neurological Disorders, Clinical Manifestations, and the Organization of Neurological Care

The new coronavirus SARS-CoV-2 and the disease it causes COVID-19 involves not only respiratory system damage, but can also lead to disorders of the central and peripheral nervous system, as well as the muscular system. This article presents published data and our own observations on the course of neurological disorders in COVID-19 patients. There is a relationship between the severity of COVID-19 and the severity and frequency of neurological manifestations. Severe neurological disorders are mostly seen in severe cases of COVID-19 and include acute cerebrovascular accidents (aCVA), acute necrotizing encephalopathy, and Guillain–Barré syndrome. Factors potentially complicating the course of COVID-19 and increasing the development of neurological complications include arterial hypertension, diabetes mellitus, and chronic cardiac and respiratory system diseases. Questions of the possible effects of human coronaviruses on the course of chronic progressive neurological diseases are addressed using multiple sclerosis (MS) as an example. We discuss the management of patients with aCVA and MS depending on the risk of developing coronavirus infection.

Extensive cerebellar involvement and cognitive impairment in COVID-19-associated acute necrotizing encephalopathy

Neurological complications of the newly appeared severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are increasingly recognized. Here, we report a case of a young male presenting with a clinical and neuroimaging scenario of an acute necrotizing encephalopathy related to the coronavirus disease 2019 (COVID-19). This case is notable by its distinct pattern of magnetic resonance imaging findings of an extensive involvement of the cerebellum, and emergence of cognitive and behavioral impairment.

The Clinical and Imaging Characteristics Associated With Neurological Sequelae of Pediatric Patients With Acute Necrotizing Encephalopathy

Background: Acute necrotizing encephalopathy of childhood (ANE) is a rare but rapidly progressing encephalopathy. Importantly, the exact pathogenesis and evidence-based treatment is scarce. Thus, we aimed to identify the clinical, imaging, and therapeutic characteristics that associated with prognosis of pediatric ANE patients. Methods: A retrospective study was conducted on pediatric patients with ANE who were admitted to Wuhan Children's Hospital between January 2014 and September 2019. All cases met the diagnostic criteria for ANE proposed by Mizuguchi in 1997. The clinical information and follow-up data were collected. The prognostic factors were analyzed by trend chi-square test and Goodman-Kruskal gamma test. Results: A total of 41 ANE patients ranging in age from 8.9 to 142 months were included in this study. Seven cases (17%) died, and the other 34 survivors had different degrees of neurological sequelae. Factors tested to be significantly correlated with the severity of neurological sequelae were the intervals from prodromal infection to acute encephalopathy (G = -0.553), conscious disturbance (r = 0.58), endotracheal intubation (r = 0.423), elevation of alanine aminotransferase (r = 0.345), aspartate aminotransferase (r = 0.393), and cerebrospinal fluid protein (r = 0.490). In addition, dynamic magnetic resonance imaging (MRI) evaluation on follow-up revealed that the total numbers of brain lesion location (χ² = 6.29, P < 0.05), hemorrhage (r = 0.580), cavitation (r = 0.410), and atrophy (r = 0.602) status were significantly correlated with the severity of neurological sequelae, while early steroid therapy (r = -0.127 and 0.212, respectively) and intravenous immunoglobulin (IVIG) (r = 0.111 and -0.023, respectively) within 24 h or within 72 h after onset showed no association. Conclusions: Intervals from prodromal infection to acute encephalopathy (≤1 day), total numbers of brain lesion location (≥3), the recovery duration of hemorrhage and atrophy (>3 months), and the presence of cavitation predict severe neurological sequelae in pediatric patients with ANE. Early treatments, including steroid therapy and IVIG, had no correlation with better outcomes. Further studies are needed to establish a consensus guideline for the management of ANE.

Presentation and Outcome of Acute Necrotizing Encephalopathy of Childhood: A 10-Year Single-Center Retrospective Study From Hong Kong

Acute necrotizing encephalopathy (ANE) is a rare disease in childhood. We reviewed the 10-year data from a local pediatric department, reported the clinical characteristics, laboratory tests, neuroimaging findings, and outcome of the acute necrotizing encephalopathy cases and identified the potential factors affecting the outcome. Eight episodes of acute necrotizing encephalopathy among 7 patients were recorded, in which all of them had an initial presentation of fever and seizure. We identified that acute necrotizing encephalopathy patients with a severe score of Glasgow Coma Scale (GCS) on presentation, brainstem involvement in magnetic resonance imaging (MRI) of the brain, and higher MR imaging scores were associated with worse outcome. Association of outcome with acute necrotizing encephalopathy severity score, platelet count, and serum alanine aminotransferase level did not reach a statistically significant level. These results highlight the importance of combined clinical, laboratory, and neuroimaging findings in determining the prognostic outcome of acute necrotizing encephalopathy patients.

[Two adult patients with acute necrotizing encephalopathy following influenza virus infection]

Influenza encephalopathy is characterized by high fever, disturbance of consciousness following influenza virus infection. We encountered 2 adult patients with influenza-associated acute necrotizing encephalopathy (Case 1, a 70-year-old woman with diabetes; Case 2, a 49-year-old woman with multiple myeloma), showing hemorrhagic lesions in the bilateral thalamus. Case 1 presented with fever and disturbance of consciousness followed by status epilepticus, and Case 2 developed fever and drowsiness as initial manifestation. Influenza type A was positive in Case 1 and influenza type B was positive in Case 2. In the acute phase, 2 patients required respiratory ventilation and were treated with anti-influenza drug, steroid and immunoglobulin. Cognitive impairment remained in the both patients in the chronic phase. When acute necrotizing encephalopathy is suspected, intensive treatment should be started as early as possible to improve clinical outcome of patients.

Use of MRI in the diagnosis and prognosis of acute necrotizing encephalopathy in a Chinese teenager: A case report

RATIONALE

Acute necrotizing encephalopathy (ANE) is a rapidly progressing disease associated with frequent neurologic sequelae and has poor prognosis. Currently, the diagnosis and treatment of ANE rely on neuroradiologic findings and offering supportive care. Here, we report the successful treatment of a teenager diagnosed with ANE using combination of high-dose methylprednisolone and oseltamivir.

PATIENT CONCERNS

The patient, a 15-year-old female, presented with impaired consciousness and seizures secondary to acute upper respiratory tract infection. A series of brain magnetic resonance images (MRIs) were obtained toward establishing a possible diagnosis.

DIAGNOSIS

Based on the history of presenting illness and subsequent brain MRI scans, the patient was diagnosed to be suffering from ANE.

INTERVENTIONS

Following the diagnosis, the patient was placed on therapy comprising of high-dose methylprednisolone and oseltamivir.

OUTCOMES

After treatment with methylprednisolone and oseltamivir for 15 days, the patient recovered nearly completely from ANE as confirmed by subsequent brain MRI scans. No complications or other emerging clinical symptoms were noted for the duration of follow-up that lasted 6 months.

LESSONS

Contrary to common reports, ANE can occur beyond pediatric populations and its treatment should not be restricted to supportive care. Our case suggests that the use of high-dose corticosteroids and oseltamivir leads to promising prognosis.

Acute necrotizing encephalopathy in an adult with influenza A infection

Acute necrotizing encephalopathy following influenza infection is a rapidly progressing disease with high morbidity. Although the neurological disorder is sometimes reported in children, it is very rare in adults. We herein describe an adult with acute necrotizing encephalopathy captured on a series of brain magnetic resonance images. A 55-year-old man had fever and impaired consciousness. He was diagnosed with influenza A (H1N1). Brain magnetic resonance imaging revealed symmetrical lesions in the cerebellum and basal nucleus, showing typical acute necrotizing encephalopathy. Physicians should know that influenza-associated acute necrotizing encephalopathy can occur even in middle-aged adults.

Influenza Virus-Associated Fatal Acute Necrotizing Encephalopathy: Role of Nonpermissive Viral Infection?

In 2014, two unusual peaks of H1N1 influenza outbreak occurred in Nakhon Ratchasima Province, in Thailand. Among 2,406 cases, one of the 22 deaths in the province included a 6-year-old boy, who initially presented with acute necrotizing encephalopathy. On the other hand, his sibling was mildly affected by the same influenza virus strain, confirmed by whole-genome sequencing, with one silent mutation. Absence of acute necrotizing encephalopathy and other neurological illnesses in the family and the whole province, with near identical whole viral genomic sequences from the two siblings, and an absence of concomitant severe lung infection (cytokine storm) at onset suggest nonpermissive infection as an alternative pathogenetic mechanism of influenza virus.

Familial acute necrotizing encephalopathy without RANBP2 mutation: Poor outcome

Most childhood cases of acute necrotizing encephalopathy (ANE) involve neither family history nor recurrence. ANE occasionally occurs, however, as a familial disorder or recurs in Caucasian patients. A mutation of RAN-binding protein 2 (RANBP2) has been discovered in more than one half of familial or recurrent ANE patients. In contrast, there has been no report of this mutation in East Asia. Here, we report the first sibling cases of typical ANE in Japan, with poor outcome. DNA analysis of genes associated with ANE or other encephalopathies, including RANBP2 and carnitine palmitoyl transferase II (CPT2), indicated neither mutations nor disease-related polymorphisms. On literature review, recurrent or familial ANE without the RANBP2 mutation has a more severe outcome and greater predilection for male sex than that with the RANBP2 mutation. This suggests that there are unknown gene mutations linked to ANE.

Acute Postviral Encephalopathy: Pathologic and Radiologic Correlation in an Atypical Case

The authors report a case of fatal acute encephalopathy following influenza infection, with slightly atypical pathological and imaging findings. A healthy 8-year-old boy with probable recent influenza A/B infection admitted for refractory seizures was placed on phenobarbital coma and later developed hemodynamic instability. Magnetic resonance imaging revealed bilateral cerebral and cerebellar white matter lesions and microhemorrhages. Following his demise, the autopsy revealed a large area of necrosis in the right centrum semiovale with similar lesions in the temporal and cerebellar regions. Microscopically, there was extensive coagulative necrosis, compatible with necrotizing white matter encephalopathy, and neuronal loss suggesting superimposed hypoxic–ischemia. The acute progressive neurologic deterioration was partly reminiscent on acute necrotizing encephalopathy, a condition recently associated with influenza A. In acute necrotizing encephalopathy, typical brain findings are characterized by bilateral thalamic necrosis/petechiae with variable white matter edema. The somewhat atypical findings in our case can relate to superadded cardiovascular collapse and hypoxic–ischemic effects.

Hypoxic-ischemic encephalopathy mimicking acute necrotizing encephalopathy

BACKGROUND

Acute necrotizing encephalopathy is a rare childhood syndrome associated with distinct and unifying neuroimaging features that are often used for the diagnosis of this entity.

PATIENT

We describe a previously healthy 9-month-old girl who presented with upper respiratory symptoms, suspected seizures, and positive nasopharyngeal rapid antigen test for influenza A virus. Magnetic resonance imaging revealed signal abnormality in both thalami, bilateral caudate nuclei, brainstem tegmentum, subcortical white matter, and cerebellar hemispheres, suggestive of acute necrotizing encephalopathy. She subsequently had a cardiac arrest, was placed on extracorporeal membrane oxygenation, and treated with methylprednisone, intravenous immunoglobulin, and plasmapheresis without apparent clinical response. On autopsy, neuropathology showed evidence of hypoxic-ischemic injury but lacked evidence of hemorrhagic necrosis, which is typically associated with acute necrotizing encephalopathy.

CONCLUSION

Combined clinical and neuroimaging features may be suggestive but not sufficient for the diagnosis of acute necrotizing encephalopathy.

Neurologic aspects of influenza viruses

Although influenza A and B viruses are primarily known as respiratory viruses and mainly infected only the upper respiratory tract in humans, patients with influenza often develop signs and symptoms that are not due to the respiratory system. Frequently individuals with influenza develop headaches, meningismus, and even seizures in addition to their typical respiratory symptoms. In the past decades, influenza viruses have also been associated with serious non-respiratory signs. The famous 1918 strain of influenza was associated with von Economo's encephalitis lethargica and postencephalitic parkinsonism. In the 1960s influenza virus infections in children were associated with Reye's syndrome characterized often by fatty non-inflammatory hepatic disease and an encephalopathy with marked non-inflammatory cerebral edema. Intermittently children with influenza develop focal myalgia and myositis. Guillain–Barré syndrome was epidemiologically associated with the 1978 killed influenza vaccine but not subsequent vaccines. Although occasional children with influenza have developed encephalopathy, from 2000 through 2004 there was an increase in the number of serious cases of acute necrotizing encephalopathy accompanying infection with the influenza A 2009 strain. The current H5N1 strain of bird influenza occasionally infects humans with a high mortality rate and some appear to have central nervous signs. This chapter explores what is known about these influenza neurologic associations.