Acute necrotising encephalopathy of childhood: a new syndrome presenting with multifocal, symmetric brain lesions

Acute necrotizing encephalopathy in adult patients with influenza: a case report and review of the literature

The neurological complications of influenza affect mainly the pediatric Asian population. In the category of influenza-associated encephalopathy, acute necrotizing encephalopathy (ANE) is a rapidly progressive and fulminant brain disorder associated with significant neurological sequelae and mortality. To date, only a few adult cases of influenza-associated ANE have been reported. We describe a 44-year-old woman who presented with rapid progression of consciousness impairment and recurrent generalized convulsions. Influenza was diagnosed three days prior to presentation, and infection with influenza A (H3N2) pdm09 was subsequently confirmed. A diagnosis of ANE was made based on the presence of characteristic brain MRI findings, the exclusion of central nervous system infection, and an elevated serum interleukin-6 level. Pulse steroid therapy followed by tocilizumab was initiated, which led to clinical stabilization and improvement. Genetic testing revealed that the patient carried heterozygous human leukocyte antigen DQB1 03:03 and DRB1 09:01 genotypes. An analysis of the adult cases of influenza-associated ANE in the literature and the present case revealed a wide range of ages (22-71 years), a short interval (median 3 days) between the clinical onset of influenza and ANE, and a high overall mortality rate (32%). The thalamus was the most frequent (91%) location of the lesions. Our report highlights the importance of identifying this devastating but treatable neurological complication of influenza in adults, especially those of Asian descent. As a cytokine storm is the most accepted pathogenic mechanism for ANE, cytokine-directed therapies may be promising treatments for which further investigation is warranted.

International consensus definitions for infection-triggered encephalopathy syndromes

AIM

To develop standardized diagnostic criteria for 'infection-triggered encephalopathy syndrome (ITES)' and five specific clinical syndromes of ITES.

METHOD

The draft definitions were based on existing criteria, standardized, and discussed by a panel of international experts using nominal group technique over 18 months to achieve consensus. All criteria use the same format: (1) presence of infection/fever; (2) clinical features including encephalopathy; (3) neuroradiological features on magnetic resonance imaging; (4) exclusion of other causes.

RESULTS

We first highlighted differences between ITES and infectious and autoimmune encephalitis, which is the most important differential diagnosis. Consensus was achieved to define five specific ITESs: acute encephalopathy with biphasic seizures and late reduced diffusion; acute necrotizing encephalopathy; mild encephalopathy with a reversible splenial lesion; acute fulminant cerebral oedema; and acute shock with encephalopathy and multiorgan failure. Two further conditions that are currently classified as epilepsy syndromes but have similar features to ITES, namely febrile infection-related epilepsy syndrome and hemiconvulsion-hemiplegia-epilepsy syndrome, are also discussed.

INTERPRETATION

The consensus definition is expected to improve awareness of this disease concept, provide diagnostic framework, and facilitate future international research and clinical trials.

Acute necrotizing encephalopathy infected with the SARS-CoV-2 in children: Case series and literature review of clinical outcomes with the use of Tocilizumab

BACKGROUND AND OBJECTIVE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes acute necrotizing encephalopathy (ANE), which has a high mortality rate and severe sequelae. This study aimed to identify ANE early and evaluate the usefulness of tocilizumab in ANE treatment.

METHODS

We retrospectively included eight paeefediatric ANE cases infected with SARS-CoV-2 at Xi'an Children's Hospital, China, from December 1, 2022 to May 1, 2023. A literature search was performed using the PUBMED, SPRING, SCOPUS, and EMBASE databases. This study included eleven patients. Clinical characteristics, laboratory test results, imaging features, and treatment options were analysed.

RESULTS

Eight of the 19 cases (42 %) died, one (5 %) recovered, and nine (47 %) improved with residual neurological dysfunction. Eighteen patients presented with fever, with 56 % having ≥40 °C. Twelve patients (63 %) presented with dysfunction consciousness. Eight (42 %) patients experienced frequent convulsions. All eight patients in our hospital had elevated procalcitonin levels (mean: 21.32 ng/mL, range: 0.10-89.40 ng/mL). Alanine aminotransferase levels were elevated (mean: 632.81 U/L, range: 13.00-2251.00 U/L) in six patients. Seven patients showed elevated uric acid levels(mean: 396.50 μmol/L, range: 157.00-660.00 μmol/L). Brain imaging indicated that all the patients had symmetrical injuries to the bilateral thalami, accompanied by symmetrical injuries in the cerebrum, cerebellum, basal ganglia, and brain stem. Compared with the classical treatment (n = 9), the combination with tocilizumab (n = 6) showed a statistically difference in mortality (p = 0.028 < 0.05).

CONCLUSION

The typical clinical manifestations of ANE in children with SARS-CoV-2 infection are acute onset with high fever, frequent convulsions and rapidly worsening disturbance of consciousness. Tocilizumab treatment could reduces mortality in ANE.

Severe Neurological Manifestation Associated With Coronavirus Disease 2019 in Children During the Omicron Variant-Predominant Period

BACKGROUND

The Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to be more infectious and less severe than the other variants. Despite the increasing number of symptomatic patients, severe neurological complications in children with the Omicron variant have been reported rarely, unlike with wild-type or Delta variants. This study aimed to investigate severe neurological complications in children with Omicron variant infection.

METHODS

We conducted a retrospective study of 17 pediatric patients with severe neurological manifestations associated with coronavirus disease 2019 in Korea during the Omicron variant prevalence, from January 1 to April 30, 2022.

RESULTS

Among the 17 patients, 11 had pre-existing neurological disabilities and nine met the criteria for multisystem inflammatory syndrome in children (MIS-C). Four of the five vaccine-eligible patients (12 years and older) were unvaccinated. Severe neurological manifestations included acute necrotizing encephalopathy, acute fulminant cerebral edema, acute disseminated encephalomyelitis, basal ganglia encephalitis, unclassified severe encephalopathy/encephalitis, and refractory status dystonicus. Patients with MIS-C and underlying neurological disabilities had longer median hospital and intensive care unit stays compared with those without these conditions. Five patients survived with new neurological deficits at the one-year follow-up, and three died, all of whom had underlying neurological disabilities.

CONCLUSIONS

This study shows that severe neurological complications in pediatric patients with the Omicron variant of SARS-CoV-2 occur infrequently but may lead to significant morbidity and mortality, especially among those with pre-existing neurological disabilities and unvaccinated individuals. Continued efforts are necessary to prevent and manage such complications in these vulnerable populations.

Two siblings with acute necrotizing encephalopathy associated with variants of LARS1

Acute necrotizing encephalopathy (ANE) is a rapidly progressive encephalopathy of unknown etiology. The underlying mechanisms are highly heterogeneous, often including genetic backgrounds. Variants of LARS1, encoding the leucyl-tRNA synthetase 1, are responsible for infantile liver failure syndrome 1. We describe two siblings with ANE caused by compound heterozygous variants of LARS1. Patient 1 was a 17-month-old girl. She presented with generalized seizure and liver dysfunction due to influenza type A infection. Brain magnetic resonance imaging on day 4 of onset showed diffuse high-intensity signals consistent with ANE. She died on day 10. Patient 2, a younger male sibling of patient 1, had mild to moderate developmental delay and growth failure at the age of 18 months. He showed a markedly elevated level of transaminases triggered by infection with human herpesvirus 6. On day 4 of onset, he had generalized seizures. Brain computed tomography showed a diffuse symmetrical hypodensity consistent with ANE. He died on day 7. Whole exome sequencing identified the compound heterozygous variants in LARS1 (NM_020117.11) as c.83_88delinsAATGGGATA, p.(Arg28_Phe30delinsLysTryAspIle) and c.1283C>T, p.(Pro428Leu) in both siblings. The severe neurologic phenotype, found in our patients, reflects the complicated pathogenesis of LARS1-related disorder.

Clinical characteristics and genetic analysis of children with Omicron BF.7.14 type novel coronavirus-related acute necrotizing encephalopathy

Background

To explore the clinical characteristics, etiological factors, and clinical-related genetic variant of children with acute necrotizing encephalopathy (ANE) related to the Omicron BF.7.14 novel coronavirus.

Methods

Genomic variations were detected through whole exome sequencing. Additionally, we summarized the clinical data to explore the inheritance patterns associated with novel coronavirus-related ANE.

Results

This study included four patients (2 males and 2 females) with an average age of 2.78 ± 1.93 years. All the patients had prodromal symptoms of Omicron BF.7.14 virus infection, and exhibited symptoms such as altered consciousness, seizures and cognitive/language disturbances. Cranial MRI scans revealed damage to the thalamus, basal ganglia and brainstem. The cerebrospinal fluid (CSF) cell counts were nearly normal, but protein level in CSF increased significantly. Genetic analysis revealed a novel truncated variant of CRMP2 gene in one patient who suffered more severe coma score and prognosis and dead in the later stages. All children exhibited a decrease in the absolute count of T lymphocytes, helper T cells, suppressor T cells, and NK cells to varying degrees. Furthermore, levels of cytokines, including IL-1 β, IL-5, IL-6 and IL-8 were significantly elevated in the CSF, especially in patient with truncated variant of CRMP2 gene.

Conclusion

The Omicron BF.7.14 type novel coronavirus can lead to ANE, characterized by T cell immunosuppression and a significant increase in cytokine levels in the CSF. The truncated variation of CRMP2 gene may affect the prognosis of ANE by affecting the migration of cerebral T cells.

Identification of neurological complications in childhood influenza: a random forest model

BACKGROUND

Among the neurological complications of influenza in children, the most severe is acute necrotizing encephalopathy (ANE), with a high mortality rate and neurological sequelae. ANE is characterized by rapid progression to death within 1-2 days from onset. However, the knowledge about the early diagnosis of ANE is limited, which is often misdiagnosed as simple seizures/convulsions or mild acute influenza-associated encephalopathy (IAE).

OBJECTIVE

To develop and validate an early prediction model to discriminate the ANE from two common neurological complications, seizures/convulsions and mild IAE in children with influenza.

METHODS

This retrospective case-control study included patients with ANE (median age 3.8 (2.3,5.4) years), seizures/convulsions alone (median age 2.6 (1.7,4.3) years), or mild IAE (median age 2.8 (1.5,6.1) years) at a tertiary pediatric medical center in China between November 2012 to January 2020. The random forest algorithm was used to screen the characteristics and construct a prediction model.

RESULTS

Of the 433 patients, 278 (64.2%) had seizures/convulsions alone, 106 (24.5%) had mild IAE, and 49 (11.3%) had ANE. The discrimination performance of the model was satisfactory, with an accuracy above 0.80 from both model development (84.2%) and internal validation (88.2%). Seizures/convulsions were less likely to be wrongly classified (3.7%, 2/54), but mild IAE (22.7%, 5/22) was prone to be misdiagnosed as seizures/convulsions, and a small proportion (4.5%, 1/22) of them was prone to be misdiagnosed as ANE. Of the children with ANE, 22.2% (2/9) were misdiagnosed as mild IAE, and none were misdiagnosed as seizures/convulsions.

CONCLUSION

This model can distinguish the ANE from seizures/convulsions with high accuracy and from mild IAE close to 80% accuracy, providing valuable information for the early management of children with influenza.

Viral entry and translation in brain endothelia provoke influenza-associated encephalopathy

Influenza-associated encephalopathy (IAE) is extremely acute in onset, with high lethality and morbidity within a few days, while the direct pathogenesis by influenza virus in this acute phase in the brain is largely unknown. Here we show that influenza virus enters into the cerebral endothelium and thereby induces IAE. Three-weeks-old young mice were inoculated with influenza A virus (IAV). Physical and neurological scores were recorded and temporal-spatial analyses of histopathology and viral studies were performed up to 72 h post inoculation. Histopathological examinations were also performed using IAE human autopsy brains. Viral infection, proliferation and pathogenesis were analyzed in cell lines of endothelium and astrocyte. The effects of anti-influenza viral drugs were tested in the cell lines and animal models. Upon intravenous inoculation of IAV in mice, the mice developed encephalopathy with brain edema and pathological lesions represented by micro bleeding and injured astrocytic process (clasmatodendrosis) within 72 h. Histologically, massive deposits of viral nucleoprotein were observed as early as 24 h post infection in the brain endothelial cells of mouse models and the IAE patients. IAV inoculated endothelial cell lines showed deposition of viral proteins and provoked cell death, while IAV scarcely amplified. Inhibition of viral transcription and translation suppressed the endothelial cell death and the lethality of mouse models. These data suggest that the onset of encephalopathy should be induced by cerebral endothelial infection with IAV. Thus, IAV entry into the endothelium, and transcription and/or translation of viral RNA, but not viral proliferation, should be the key pathogenesis of IAE.

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.

Cytokine Storm Related to CD4+ T Cells in Influenza Virus-Associated Acute Necrotizing Encephalopathy

Acute necrotizing encephalopathy (ANE) is a rare but deadly complication with an unclear pathogenesis. We aimed to elucidate the immune characteristics of H1N1 influenza virus-associated ANE (IANE) and provide a potential therapeutic approach for IANE. Seven pediatric cases from a concentrated outbreak of H1N1 influenza were included in this study. The patients' CD4+ T cells from peripheral blood decreased sharply in number but highly expressed Eomesodermin (Eomes), CD69 and PD-1, companied with extremely high levels of IL-6, IL-8 in the cerebrospinal fluid and plasma. Patient 2, who showed high fever and seizures and was admitted to the hospital very early in the disease course, received intravenous tocilizumab and subsequently showed a reduction in temperature and a stable conscious state 24 h later. In conclusion, a proinflammatory cytokine storm associated with activated CD4+ T cells may cause severe brain pathology in IANE. Tocilizumab may be helpful in treating IANE.

A Young Girl with Acute Encephalopathy Who Presented with Status Epilepticus Following a Flu-Like Illness

BACKGROUND Acute necrotizing encephalopathy of childhood (ANEC) is a rare form of acute encephalopathy in children that is characterized by rapid and progressive deterioration in the patient's clinical condition. Our aim in reporting the case is to highlight the importance of early diagnoses and aggressive early management of ANEC to achieve a better outcome. We report the case of a 5-year-old girl who presented with acute progressive encephalopathy with bilateral symmetrical thalamic involvement and brainstem lesion proceeded by a flu-like illness. CASE REPORT We report a 5-year-old girl who was previously healthy. She presented with rapid progressive encephalopathy and status epilepticus following a flu-like illness. Her magnetic resonance imaging (MRI) showed significance symmetrical bilateral thalamic enhancement with brainstem lesions, which is consistent with the diagnosis of ANEC of childhood, and her initial electroencephalogram (EEG) showed severe encephalopathy. Despite extensive management of ANEC, the patient showed a poor prognosis. CONCLUSIONS ANEC is a rare, specific, devastating condition in the pediatric population. Early diagnosis and aggressive management should be initiated immediately to avoid the high mortality associated with the condition. Furthermore, to highlight the importance of the clear history of the patient who presented with rapid and progressive deterioration in the level of consciousness and status epilepticus proceeded by viral illness, a rapid neuroradiological images such as brain MRI should be obtained to confirm the diagnosis of this rare condition. We also seek to increase awareness of this disorder among healthcare workers and general practitioners.

Children with severe neurological symptoms associated with SARS-CoV-2 infection during Omicron pandemic in China

BACKGROUND

To analyze the clinical characteristics and outcomes of children with severe neurological symptoms associated with the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection during the Omicron pandemic in China.

METHODS

This study used a questionnaire to obtain data from pediatric intensive care unit (PICU) centers in seven tertiary hospitals in Northeast China from December 1, 2022, to January 31, 2023.

RESULTS

A total of 255 patients were confirmed to have SARS-CoV-2 infection, and 45 patients (17.65 %) were included in this study. Of these, seven (15.6%) patients died, and the median time from admission to death was 35 h (IQR, 14-120 h). Twenty (52.6%) survivors experienced neurological sequelae. Patients with platelet counts lower than 100 × 109/L had a higher incidence of complications such as multiple organ dysfunction, mechanical ventilation rate, and mortality. Cranial magnetic resonance imaging (MRI) always reveals cerebral tissue edema, with some severe lesions forming a softening site.

CONCLUSION

Children infected with SARS-CoV-2 often exhibit severe neurological symptoms, and in some cases, they may rapidly develop malignant cerebral edema or herniation, leading to a fatal outcome. An early decrease in platelet count may associated with an unfavorable prognosis.

IMPACT

Since early December 2022, China has gradually adjusted its prevention and control policy of SARS-CoV-2; Omicron outbreaks have occurred in some areas for a relatively short period. Due to the differences in ethnicity, endemic strains and vaccination status, there was a little difference from what has been reported about children with SARS-CoV-2 infection with severe neurological symptoms in abroad. This is the first multicenter clinical study in children with nervous system involvement after acute SARS-CoV-2 infection in China, and helpful for pediatricians to have a more comprehensive understanding of the clinical symptoms and prognosis of such disease.

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.

A Rare Case of COVID-19 Related Acute Necrotizing Encephalopathy With the RANBP2 Mutation in a Pediatric Patient

Acute necrotizing encephalopathy (ANE) is a rare childhood neurological disorder. The familiar type of ANE (ANE1) is associated with a mutation in the RANBP2 gene. Both SARS-CoV-2 and RANBP2 mutations are responsible for the manifestation of a hyper-inflammatory response that invades the central nervous system and plays a key role in the rapid progression of encephalopathy.

Ferritin as an Effective Predictor of Neurological Outcomes in Children With Acute Necrotizing Encephalopathy

BACKGROUND

Acute necrotizing encephalopathy (ANE) is a fulminant disease with poor prognosis. Cytokine storm is the important phenomenon of ANE that affects the brain and multiple organs. The study aimed to identify whether hyperferritinemia was associated with poor prognosis in patients with ANE.

METHODS

All patients with ANE had multiple symmetric lesions located in the bilateral thalami and other regions such as brainstem tegmentum, cerebral white matter, and cerebellum. Neurological outcome at discharge was evaluated by pediatric neurologists using the Pediatric Cerebral Performance Category Scale. All risk factors associated with poor prognosis were further analyzed using receiver operating characteristic curve analysis.

RESULTS

Twenty-nine patients with ANE were enrolled in the current study. Nine (31%) patients achieved a favorable neurological outcome, and 20 (69%) patients had poor neurological outcomes. results The group of poor neurological outcome had significantly higher proportion of shock on admission and brainstem involvement. Based on multivariate logistic regression analysis, ferritin, aspartate aminotransferase (AST), and ANE severity score (ANE-SS) were the predictors associated with outcomes. The appropriate cutoff value for predicting neurological outcomes in patients with ANE was 1823 ng/mL for ferritin, 78 U/L for AST, and 4.5 for ANE-SS. Besides, comparison analyses showed that higher level of ferritin and ANE-SS were significantly correlated with brainstem involvement (P < 0.05).

CONCLUSIONS

Ferritin may potentially be a prognostic factor in patients with ANE. Hyperferritinemia is associated with poor neurological outcomes in patients with ANE and ferritin levels more than 1823 ng/mL have about eightfold increased risk of poor neurological outcome.

Defining the Clinicoradiologic Syndrome of SARS-CoV-2 Acute Necrotizing Encephalopathy: A Systematic Review and 3 New Pediatric Cases

BACKGROUND AND OBJECTIVES

We characterize clinical and neuroimaging features of SARS-CoV-2-related acute necrotizing encephalopathy (ANE).

METHODS

Systematic review of English language publications in PubMed and reference lists between January 1, 2020, and June 30, 2023, in accordance with PRISMA guidelines. Patients with SARS-CoV-2 infection who fulfilled diagnostic criteria for sporadic and genetic ANE were included.

RESULTS

From 899 articles, 20 cases (17 single case reports and 3 additional cases) were curated for review (50% female; 8 were children). Associated COVID-19 illnesses were febrile upper respiratory tract infections in children while adults had pneumonia (45.6%) and myocarditis (8.2%). Children had early neurologic deterioration (median day 2 in children vs day 4 in adults), seizures (5 (62.5%) children vs 3 of 9 (33.3%) adults), and motor abnormalities (6 of 7 (85.7%) children vs 3 of 7 (42.9%) adults). Eight of 12 (66.7%) adults and 4 (50.0%) children had high-risk ANE scores. Five (62.5%) children and 12 (66.7%) adults had brain lesions bilaterally and symmetrically in the putamina, external capsules, insula cortex, or medial temporal lobes, in addition to typical thalamic lesions of ANE. Hypotension was only seen in adults (30%). Hematologic derangements were common: lymphopenia (66.7%), coagulopathy (60.0%), or elevated D-dimers (100%), C-reactive protein (91.7%), and ferritin (62.5%). A pathogenic heterozygous c/.1754 C>T variant in RANBP2 was present in 2 children: one known to have this before SARS-CoV-2 infection, and a patient tested because the SARS-CoV-2 infection was the second encephalopathic illness. Three other children with no prior encephalopathy or family history of encephalopathy were negative for this variant. Fifteen (75%) received immunotherapy (with IV methylprednisolone, immunoglobulins, tocilizumab, or plasma exchange): 6 (40.0%) with monotherapy and 9 (60.0%) had combination therapy. Deaths were in 8 of 17 with data (47.1%): a 2-month-old male infant and 7 adults (87.5%) of median age 56 years (33-70 years), 4 of whom did not receive immunotherapy.

DISCUSSION

Children and adults with SARS-CoV-2 ANE have similar clinical features and neuroimaging characteristics. Mortality is high, predominantly in patients not receiving immunotherapy and at the extremes of age.

A nationwide survey of adenovirus-associated encephalitis/encephalopathy in Japan

BACKGROUND

Adenovirus is a major pathogen causing febrile illness among children. It may also cause acute encephalitis/encephalopathy. This study aimed to elucidate the clinical features of adenovirus-associated encephalitis/encephalopathy (AdVE) among children in Japan.

METHODS

A nationwide survey of children with AdVE was conducted. An initial survey was distributed among pediatricians to obtain information about children with AdVE treated between January 2014 and March 2019. A second survey was used to obtain the clinical information of children with AdVE from hospitals that responded to the initial survey and those identified from a literature search of the reported cases. We collected demographic data and information about symptoms of infection, neurological symptoms, laboratory parameters, treatment, and outcomes. Outcomes were determined using the Pediatric Cerebral Performance Category Score.

RESULTS

Clinical information was available for 23 children with a median age of 39 months. Two had preexisting neurological disorders and six had a history of febrile seizures. The outcome was good in 15 patients and poor in eight patients. Serum lactate dehydrogenase, glucose, and ammonia levels were higher among children with a poor outcome compared to those with a good outcome. Clinically mild encephalitis/encephalopathy with a reversible splenial lesion was the most common type (n = 8), followed by acute encephalopathy with biphasic seizures and late reduced diffusion (n = 7).

CONCLUSION

A prior history of febrile seizures was frequent in children with AdVE. Several different subtypes of acute encephalopathy were seen in children with AdVE, and the outcome was poor in those with acute encephalopathy with biphasic seizures and late reduced diffusion and hemorrhagic shock and encephalopathy syndrome. Elevated lactate dehydrogenase, glucose, and ammonia levels on admission were found to correlate with a poor outcome.

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.

Clinical characteristics and prognostic analysis of acute necrotizing encephalopathy of childhood: a retrospective study at a single center in China over 3 years

Objective

Acute Necrotizing Encephalopathy of Childhood (ANEC) is a rare, fulminant neurological disease in children with unknown mechanisms and etiology. This study summarized the clinical characteristics, treatment, and prognosis of ANEC through a retrospective analysis, providing insights into the ANEC early diagnosis and prognosis assessment.

Methods

Clinical data of children diagnosed with ANEC at the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University from July 1, 2020, to June 30, 2023, were retrospectively analyzed.

Results

There were 25 cases, 14 males and 11 females, with a median age of 3 years. Hospital admissions were mainly in the winter (14/25, 56%) and spring (9/25, 36%). All patients presented with varying degrees of fever and altered consciousness, with 92% (23/25) experiencing high body temperatures (>39.1°C) and 88% (22/25) having a Glasgow coma scale (GCS) score of ≤8. Seizures were observed in 88% (22/25) of patients. Laboratory findings indicated 100% B lymphocyte activation (14/14), and 78% (14/18) of patients showed cytokine storm (interleukin (IL)-6, IL-8, IL-10, interferon (IFN)-α). Neuroimaging showed symmetrical thalamus involvement, commonly involving basal ganglia and brainstem regions. Viral infection (23/24, 96%) was the predominant etiological finding, with 42% (10/24) of cases due to SARS-CoV-2 infection and 42% (10/24) to influenza A virus infection. Multi-organ dysfunction occurred in 68% (17/25) of patients, and 52% (13/25) died. Correlation analysis revealed the death group exhibited higher proportion of male, lower GCS scores, higher IL-6 level and a greater likelihood of associated brainstem impairment (p < 0.05).

Conclusion

ANEC is more prevalent in the winter and spring, and its etiology may be associated with B lymphocyte activation and cytokine storm following viral infections. Clinical manifestations lack specific features, with fever, consciousness disturbances, and seizures being the main presentations, particularly in cases of high fever and hyperpyrexia. ANEC progresses rapidly and has a high mortality rate. The child's gender, GCS score, IL-6 levels, and the presence of brainstem involvement can serve as important risk factors for assessing the risk of mortality.

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.

RANBP2 evolution and human disease

Ran-binding protein 2 (RANBP2)/Nup358 is a nucleoporin and a key component of the nuclear pore complex. Through its multiple functions (e.g., SUMOylation, regulation of nucleocytoplasmic transport) and subcellular localizations (e.g., at the nuclear envelope, kinetochores, annulate lamellae), it is involved in many cellular processes. RANBP2 dysregulation or mutation leads to the development of human pathologies, such as acute necrotizing encephalopathy 1, cancer, neurodegenerative diseases, and it is also involved in viral infections. The chromosomal region containing the RANBP2 gene is highly dynamic, with high structural variation and recombination events that led to the appearance of a gene family called RANBP2 and GCC2 Protein Domains (RGPD), with multiple gene loss/duplication events during ape evolution. Although RGPD homoplasy and maintenance during evolution suggest they might confer an advantage to their hosts, their functions are still unknown and understudied. In this review, we discuss the appearance and importance of RANBP2 in metazoans and its function-related pathologies, caused by an alteration of its expression levels (through promotor activity, post-transcriptional, or post-translational modifications), its localization, or genetic mutations.

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.

Biallelic variants in ribonuclease inhibitor (RNH1), an inflammasome modulator, are associated with a distinctive subtype of acute, necrotizing encephalopathy

PURPOSE

Mendelian etiologies for acute encephalopathies in previously healthy children are poorly understood, with the exception of RAN binding protein 2 (RANBP2)-associated acute necrotizing encephalopathy subtype 1 (ANE1). We provide clinical, genetic, and neuroradiological evidence that biallelic variants in ribonuclease inhibitor (RNH1) confer susceptibility to a distinctive ANE subtype.

METHODS

This study aimed to evaluate clinical data, neuroradiological studies, genomic sequencing, and protein immunoblotting results in 8 children from 4 families who experienced acute febrile encephalopathy.

RESULTS

All 8 healthy children became acutely encephalopathic during a viral/febrile illness and received a variety of immune modulation treatments. Long-term outcomes varied from death to severe neurologic deficits to normal outcomes. The neuroradiological findings overlapped with ANE but had distinguishing features. All affected children had biallelic predicted damaging variants in RNH1: a subset that was studied had undetectable RNH1 protein. Incomplete penetrance of the RNH1 variants was evident in 1 family.

CONCLUSION

Biallelic variants in RNH1 confer susceptibility to a subtype of ANE (ANE2) in previously healthy children. Intensive immunological treatments may alter outcomes. Genomic sequencing in children with unexplained acute febrile encephalopathy can detect underlying genetic etiologies, such as RNH1, and improve outcomes in the probands and at-risk siblings.

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.

Treatment of severe acute necrotizing encephalopathy of childhood with interleukin-6 receptor blockade in the first 24 h as add-on immunotherapy shows favorable long-term outcome at 2 years

BACKGROUND

Acute necrotizing encephalopathy (ANE) of childhood is a rare and devastating infection-associated acute encephalopathy. While there are no consensus treatments for ANE, recent case reports suggest a beneficial role for the use of tocilizumab, a recombinant humanized monoclonal antibody against the interleukin-6 (IL-6) receptor. The correlation of the timing of add-on tocilizumab in relation to long-term outcome has not been reported.

METHODS

We report on the timing of administration of tocilizumab in two patients classified as high-risk using the ANE severity score (ANE-SS) with respect to the long-term outcome at 2 years.

RESULTS

Case 1 was a 19-month-old previously well boy who presented to a tertiary children's hospital with seizures, evolving status dystonicus and shock. Case 2 was a three-year-old boy who presented to a peripheral hospital with fever, sepsis and encephalopathy. The patients were transferred to the tertiary intensive care unit and MRI confirmed ANE with extensive brainstem involvement. Case 1 received intravenous immunoglobulin (IVIg), methylprednisolone and tocilizumab at 21, 39 and 53 h respectively. His modified Rankin scale (mRS) at discharge and two years was unchanged at 5. The functional independence measure - for children (WeeFIM) at two years was very low (19/126). Case 2 received dexamethasone at 1 h, methylprednisolone at 21 h and IVIg and tocilizumab at 22 h. The mRS at discharge and two years was 4 and 3 respectively. The WeeFIM score at two years showed substantial improvement (96/126).

CONCLUSION

The very early use of interleukin-6 blockade as 'add-on' immunotherapy in the first 24 h demonstrates potential for improving the long-term outcome in patients classified as high-risk using the ANE-SS.

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.

Acute necrotizing encephalopathy of childhood from Eastern Africa

Key Clinical Message

Acute necrotizing encephalopathy leads to devastating neurological sequelae and even death. Clinician should try not to miss this diagnosis especially in the pediatrics whenever there are neurological symptoms due to viral infection.

Abstract

Acute necrotizing encephalopathy (ANE) is a rare disease affecting the central nervous system. It leads to devastating neurological sequelae with a mortality rate of approximately 30%. Clinicians should have high suspicion whenever there is neurologic deficit and history of viral infections especially involving upper respiratory tract in the pediatric age group.

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.

A nationwide survey of human metapneumovirus-associated encephalitis/encephalopathy in Japan

BACKGROUND

As there have been no comprehensive reports of human metapneumovirus-associated encephalopathy (hMPVE), this study examined the clinical features of hMPVE in children in Japan.

METHOD

A nationwide survey of children with hMPVE was conducted using a structured research form. An initial survey asked pediatricians about children with hMPVE treated between 2014 and 2018. A second survey obtained patient information from hospitals that responded to the initial survey and those identified as having treated cases from a literature search. We collected demographic data, symptoms of hMPV infection, neurological symptoms, laboratory data, treatment, and outcomes. Outcomes were determined using the Pediatric Cerebral Performance Category Score.

RESULT

Clinical information was available for 16 children. Their median age was 37 months. Six had preexisting neurological disorders. The interval between the onsets of infection and hMPVE was 4 days. Outcomes were good in 11 patients and poor in 5. There were no significant differences in demographic data, neurological symptoms, or laboratory data between the patients with good and poor outcomes. The encephalopathy subtypes were acute encephalopathy with biphasic seizures and late reduced diffusion in 3, clinically mild encephalitis/encephalopathy with a reversible splenial lesion in 3, hemorrhagic shock and encephalopathy syndrome in 2, and others in 8.

CONCLUSION

The outcomes of children with hMPVE were not very different from those of acute encephalopathy due to other viruses. We found no factors associated with poor outcomes.

Risk factors for mortality in fulminant acute necrotizing encephalopathy following influenza A in an adolescent boy

Acknowledging the risk factors of mortality and morbidity of each disease is effective for its final outcome. Recognizing these cases can have the value of preventing the occurrence of unfortunate events, such as not recommending the use diclofenac in an influenza epidemic.

Neurological features related to influenza virus in the pediatric population: a 3-year monocentric retrospective study

Influenza virus is generally characterized by fever, myalgia, and respiratory symptoms. Neurological entities have already been described, such as acute necrotizing encephalitis (ANE). We aimed to highlight the non-exceptional nature and explore the clinical spectrum and evolution of neurological features related to influenza virus in children. This monocentric observational study included patients under 18 years old, positive for influenza virus, between January 2017 and April 2019 in a pediatric university hospital. Patients were classified into two groups: those with or without a previous significant neurological or metabolic disorder. Two hundred eighty-nine children were identified with influenza infection. Thirty seven had a neurological manifestation: 14 patients who had previous significant neurological or metabolic disorder and 23 patients with no medical history. We identified several clinical patterns: 22 patients had seizures, 7 behavior disorders, 5 disturbances of consciousness, and 3 motor deficits. Four were diagnosed with a known influenza-associated neurological syndrome: 1 ANE, 1 cytotoxic lesion of the corpus callosum, 1 hemiconvulsion-hemiplegia-epilepsia syndrome, and 1 recurrent encephalitis in the context of a RANBP2 mutation. The neurological outcome was favorable in most cases. None of the patients with previous significant disorder retained sequalae or had a recurrence. Two patients had a fatal outcome, and both had a predisposing disorder.

CONCLUSION

Various neurological manifestations can be associated with influenza virus. Certain entities led to a poor prognosis, but in most cases, symptoms improved within a few days. The severity of the neurological manifestations correlated with previous neurological or metabolic disorders.

WHAT IS KNOWN

• Influenza viruses are well known pathogens with a seasonal epidemic evolution, particularly affecting children. These viruses cause acute fever with respiratory symptoms, associated with myalgia and headaches. Neurological presentation in influenza-virus infection is a well-established possibility as influenza virus is considered to be responsible for 27 to 36% of childhood encephalitis. Some specific and severe entity as acute necrotizing encephalitis, cytotoxic lesion of the corpus callosum, or Hemiconvulsion-hemiplegia-epilepsy syndrome are well described.

WHAT IS NEW

• In a French monocentric cohort of 37 children with influenza-related neurologic manifestations, the majority of these manifestations, including seizure, drowsiness, motor deficiency, hallucination… are self limiting and do not lead to after-effects. In rare cases (4/37), they may reveal severe encephalitis requiring rapid and appropriate treatment. Otherwise, comparison of a group of 14 children with underlying neurological or metabolic disorder with a group of 23 children free of any significant disorder show that the severity of the neurological manifestations was largely related to previous neurological or metabolic disorders highlighting the importance of vaccination in this population.

Factors associated with outcomes of severe acute necrotizing encephalopathy: A multicentre experience in Malaysia

This case series compared clinical variables and various combinations of immunotherapy received with outcomes of patients with severe acute necrotizing encephalopathy (ANE). We performed a retrospective review of clinical variables, immunotherapy received, and outcomes (based on the modified Rankin Scale) in Malaysia between February 2019 and January 2020. Twenty-seven children (12 male), aged 7 months to 14 years (mean 4 years) at diagnosis were included. Of these, 23 had an ANE severity score of 5 to 9 out of 9 (high risk). Eleven patients received tocilizumab (four in combination with methylprednisolone [MTP], seven with MTP + intravenous immunoglobulin [IVIG]) and 16 did not (two received MTP alone, 14 received MTP + IVIG). Nine died. Among the survivors, six had good outcomes (modified Rankin Score 0-2) at 6 months follow-up. All patients who received tocilizumab in combination with MTP + IVIG survived. Twenty children received first immunotherapy within 48 hours of admission. No significant association was found between the timing of first immunotherapy with outcomes. Those with brainstem dysfunction (p = 0.016) were observed to have poorer outcomes. This study showed a trend towards better survival when those with severe ANE were treated with tocilizumab in combination with MTP + IVIG. However, larger studies will be needed to determine the effect of this regime on the long-term outcomes.

Severe pediatric acute encephalopathy syndromes related to SARS-CoV-2

Background and objectives

To clarify whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection cause acute encephalopathy in children and which are the most common syndromes that cause them and what are the outcomes.

Methods

A nationwide web-based survey among all members of the Japanese Society of Child Neurology to identify pediatric patients aged < 18 years who developed acute encephalopathy in Japan between 1 January 2020 and 31 May 2022 associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection confirmed by polymerase chain reaction or antigen tests using pharyngeal swabs. Acute encephalopathy was defined as acute onset of impaired consciousness lasting > 24 h or an altered mental state; neurological symptoms arising within 2 weeks of onset of COVID-19 or multisystem inflammatory syndrome in children (MIS-C)/pediatric inflammatory multisystem syndrome (PIMS); evidence of SARS-CoV-2 infection; and reasonable exclusion of other diseases. Patients were divided into the known clinico-radiological acute encephalopathy syndrome group and unexplained or unclassifiable acute encephalopathy group. Outcomes were assessed by pediatric cerebral performance category (PCPC) score at hospital discharge.

Results

Of the 3,802 society members, 217 representing institutions responded, and 39 patients with suspected acute encephalopathy were reported, of which 31 met inclusion criteria. Of these patients, 14 were diagnosed with known clinico-radiological acute encephalopathy syndromes, with acute encephalopathy with biphasic seizures and late reduced diffusion (five patients) being the most common. Five developed acute encephalopathy associated with MIS-C/PIMS. Among 31 patients, 9 (29.0%) had severe sequelae or died (PCPC ≥ 4). Two of three patients with encephalopathy with acute fulminant cerebral edema and two with hemorrhagic shock and encephalopathy syndrome died. The PCPC scores were higher in the known clinico-radiological acute encephalopathy syndrome group than in the unexplained or unclassifiable acute encephalopathy group (P < 0.01).

Discussion

Acute encephalopathy related to SARS-CoV-2 infection was demonstrated to be more severe than that caused by other viruses in Japan. Acute encephalopathy syndromes characterized by specific neuroradiological findings was associated with poor clinical outcomes.

Pediatric recurrent acute necrotizing encephalomyelitis, RANBP2 genotype and Sars-CoV-2 infection: Diagnosis, pathogenesis and targeted treatments from a case study

Acute necrotizing encephalopathy (ANE) is a rare disease not yet described in children with Covid-19. RANBP2 gene variations are implicated in recurrences in the genetic form of ANE, the so called ANE1. We report the first case of pediatric ANE1 following Sars-CoV-2 infection. She had a first episode at 2 years of age following influenza type A with full recovery, many other respiratory and non-respiratory febrile viral infections without recurrences and a severe recurrence following Sars-CoV-2 infection, suggesting a potentiation effect on cytokine cascade. Her MRI showed the typical pattern of injury resembling that of mitochondrial disorders, and supported the role of RANBP2 in mitochondrial homeostasis. This case rises attention on diagnostic challenges and offers several interesting tips for discussion about new perspectives in pathogenesis and targeted treatments.

COVID-19 related acute necrotizing encephalopathy with extremely high interleukin-6 and RANBP2 mutation in a patient with recently immunized inactivated virus vaccine and no pulmonary involvement

Background

We report the first case of COVID-19 associated acute necrotizing encephalopathy (ANE) without pulmonary disease in a patient with an extremely high interleukin-6 (IL-6) level and Ran Binding Protein 2 (RANBP2) mutation.

Case presentation

A 29-year-old woman recently immunized with inactivated viral vaccine—BBIBP32-CorV (Sinopharm) presented with alteration of consciousness. Her body temperature was 37° Celsius, blood pressure 42/31 mmHg, heart rate 130 bpm, respiratory rate 20 per minute, and oxygen saturation 98%. Respiratory examination was unremarkable. Neurological examination revealed stupor but preserved brainstem reflexes. Non-contrast computerized tomography of the brain showed symmetrical hypodense lesions involving bilateral thalami and cerebellar hemispheres characteristic of ANE. No pulmonary infiltration was found on chest radiograph. SARS-CoV-2 was detected by PCR; whole genome sequencing later confirmed the Delta variant. RANBP2 gene analysis revealed heterozygous Thr585Met mutation. Serum IL-6 was 7390 pg/mL. Urine examination showed pyelonephritis. Her clinical course was complicated by seizure, septic shock, acute kidney injury, and acute hepatic failure. She later developed coma and passed away in 6 days.

Conclusions

ANE is caused by cytokine storm leading to necrosis and hemorrhage of the brain. IL-6 was deemed as a prognostic factor and a potential treatment target of ANE in previous studies. RANBP2 missense mutation strongly predisposes this condition by affecting mitochondrial function, viral entry, cytokine signaling, immune response, and blood–brain barrier maintenance. Also, inactivated vaccine has been reported to precipitate massive production of cytokines by antibody dependent enhancement (ADE). The true incidence of COVID-19 associated ANE is not known as were the predictors of its development. We proposed these potential two factors (RANBP2 mutation and ADE) that could participate in the pathogenesis of ANE in COVID-19 apart from SARS-CoV2 infection by itself. Further study is needed to confirm this hypothesis, specifically in the post-vaccination period. Role of RANBP2 mutation and its application in COVID-19 and ANE should be further elaborated.

Pathogenesis and Preventive Tactics of Immune-Mediated Non-Pulmonary COVID-19 in Children and Beyond

The COVID-19 pandemic has evolved to immune escape and threatened small children and the elderly with a higher severity and fatality of non-pulmonary diseases. These life-threatening non-pulmonary COVID-19 diseases such as acute necrotizing encephalopathies (ANE) and multisystem inflammatory syndrome in children (MIS-C) are more prevalent in children. However, the mortality of multisystem inflammatory syndrome in adults (MIS-A) is much higher than that of MIS-C although the incidence of MIS-A is lower. Clarification of immunopathogenesis and genetic susceptibility of inflammatory non-pulmonary COVID-19 diseases would provide an appropriate guide for the crisis management and prevention of morbidity and fatality in the ongoing pandemic. This review article described three inflammatory non-pulmonary COVID-19 diseases including (1) meningoencephalitis (ME), (2) acute necrotizing encephalopathies (ANE), and (3) post-infectious multisystem inflammatory syndrome in children (MIS-C) and in adults (MIS-A). To prevent these life-threatening non-pulmonary COVID-19 diseases, hosts carrying susceptible genetic variants should receive prophylactic vaccines, avoid febrile respiratory tract infection, and institute immunomodulators and mitochondrial cocktails as early as possible.

Acute necrotizing encephalopathy associated with lymphoma-associated hemophagocytic lymphohistiocytosis: A case report and literature review

Damage associated with lymphoma-associated hemophagocytic lymphohistiocytosis (LA-HLH) to the central nervous system (CNS) is not uncommon. However, the combination with brain damage resembling acute necrotizing encephalopathy (ANE) is rarely reported. Herein, we introduce the diagnosis and treatment of a case of ANE associated with LA-HLH in our hospital and review the relevant literature. After treatment, the child was discharged with only dysarthria and decreased sucking ability. The child is now discharged from the hospital for 6 months with regular follow-up. There were no disease recurrence signs. LA-HLH and ANE were related to cytokine storm. Therefore, early steroid application is essential for treating these diseases.

Adult-onset Still's disease with concurrent acute necrotizing encephalopathy: a case report

Background

Acute necrotizing encephalopathy (ANE) is a rare encephalopathy characterized by multiple symmetrical brain lesions, mainly involving thalami. Adult-onset Still’s disease (AOSD) is a rare systemic inflammatory condition of unknown cause characterized by fever, sore throat, rash and joint pain. Both entities are considered to be triggered by infections and associated with hypercytokinemia.

Case presentation

A 46-year-old male was diagnosed with AOSD at local hospital because of 3-week-long high fever, sore throat, arthralgia, transient skin rash, lymphadenopathy, leukocytosis, hyperferritinemia, and absence of antinuclear antibodies (ANA) and rheumatoid factor (RF). Corticosteroids were not used because of delayed diagnosis. Three weeks after the onset, the patient suddenly fell unconscious and was transferred to our hospital. Brain CT and MRI revealed symmetrical lesions involving thalami, striatum and brain stem, consistent with ANE. One day after admission, his condition aggravated and brain CT revealed hemorrhage in the lesions. He died 3 days after admission.

Conclusion

We report a rare case of ANE preceded by AOSD. The underlying mechanism is still unclear. Early recognizing of the two conditions is difficult but prognostically important.

Outcomes in influenza and RANBP2 mutation-associated acute necrotizing encephalopathy of childhood

AIM

To evaluate clinical and imaging features in patients with acute necrotizing encephalopathy of childhood (ANEC) to identify predictors of RANBP2 mutations, influenza association, and long-term outcomes.

METHOD

A retrospective chart review in patients with ANEC (2012-2020) seen at a tertiary pediatric center was performed. Children were included if they had acute inflammatory lesions in the basal ganglia and pons. Variables included presenting features, imaging characteristics, RANBP2 gene testing, nasopharyngeal swab findings, therapies, and long-term outcomes.

RESULTS

Twenty patients were included (average age at presentation 3y 6mo, interquartile range  3y 7mo, SD  2y 8mo; 14 females, six males). Three of the 20 experienced recurrences; one of the 20 died. Ten patients were influenza positive. Seven patients were RANBP2 mutation positive. A higher likelihood of hemorrhage was observed in patients who were influenza positive compared to influenza negative (p=0.048). Patients with influenza had a higher degree of thalamic hemorrhage (2, p=0.035) and greater extent of diffusion restriction (3, p=0.035) in semiquantitive analysis.

INTERPRETATION

Children with ANEC who are positive for influenza are more likely to have hemorrhage and greater thalamic swelling. RANBP2 status was predictive of relapse but not predictive of overall outcome.