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

Neurological involvement related to the influenza virus in children: A 5-year single-centre retrospective study

INTRODUCTION

Inflammation related to influenza virus infection can lead to multiple neurological presentations. Encephalitis is one of them, mostly accompanied by seizures, with different profiles depending on the epidemics and previous medical conditions.

MATERIALS AND METHODS

All children presenting neurological symptoms and positive for influenza virus RNA detection in a respiratory sample between November 2018 and April 2023, hospitalized in the Department of Paediatric Neurology of Toulouse Children's Hospital, were retrospectively analysed.

RESULTS

Among the 1,277 children diagnosed with influenza in our centre, 131 (10.3 %) were hospitalized for neurological features. The year 2020-2021 was marked by zero incidence of positive influenza tests, associated with the COVID-19 pandemic. Among the 131 patients included, 71.6 % were under 5 years old. Most of them (80.9 %) were infected by influenza A virus. The first neurological symptoms were mainly seizures in 73.3 % of patients. Possible or confirmed encephalitis was observed in 29 % of cases, including one acute necrotizing encephalopathy. Few children (6.1 %) presented with acute myositis. Twenty-seven patients (20.6 %) had a personal history of significant previous neurological disorders. Most patients (88.5 %) displayed a rapid favourable outcome, marked by the disappearance of their neurological symptoms within the first 2 days. Anti-epileptic drugs were introduced in 1.5 % of cases, and adapted in 16.8 %, mainly in patients with febrile status epilepticus and an abnormal EEG.

CONCLUSION

Neurological features were frequently associated with influenza infection in children; most were transient. Effects on long-term neurodevelopmental outcomes need to be clarified as our follow-up was limited, especially in children with pre-existing neurological conditions.

Immune-mediated encephalitis

A neurological deterioration in a child presents a significant worry to the family and often a diagnostic challenge to the clinician. A dysregulated immune response is implicated in a wide and growing spectrum of neurological conditions. In this review we consider the current paradigms in which immune-mediated encephalopathies are considered; the development of paediatric specific diagnostic criteria that facilitate early consideration and treatment of immune-mediated conditions and the limitations and potential developments in diagnostic testing. We consider the expanding phenotype of myelin oligodendrocyte glycoprotein antibody, the spectrum of virus-associated encephalopathy syndromes, and the strategies that have been employed to build an evidence base for the management of these rare conditions. Looking forward we explore the potential for advanced molecular investigations to improve our understanding of immune-mediated encephalitides and guide future treatment strategies. Recently characterized immune-mediated central nervous system disorders include new antibodies causing previously recognized phenotypes. Aggregation of conditions with similar clinical triggers, and characterization of unique imaging features in virus-associated encephalopathy syndromes. Immune treatment iscurrently guided by meta-analysis of individualized patient data and/or multi-national consensus.

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.

Acute necrotizing encephalopathy associated with COVID-19: case series and systematic review

Acute necrotizing encephalopathy (ANE) is a rare neurological complication related to COVID-19. Here we present a case series of six Chinese cases with ANE associated with COVID-19 and review all reported cases in the literature. A total of six cases with ANE related to COVID-19 were enrolled in this study. Clinical manifestations, neuroimaging data, treatment and outcomes of these patients were analyzed. A literature review was performed in Pubmed and Embase and 25 cases with clinical and neuroimaging data were collected and analyzed. Among our six cases, the age of onset ranged from 15 to 56 years, with a male-to-female ratio of nearly 1:1. All patients presented with reduced consciousness. Elevated interleukin 6 in serum and/or cerebrospinal fluid (CSF) was detected in four patients. Two patients improved clinically after intravenous methylprednisolone and intravenous immunoglobulin (IVIG). Based on the literature review, the majority of cases were from Europe and the United States (60%). Two age peaks at 10-20 years (20%) and 50-60 years (28%) were observed. Two cases were found with a heterozygous Thr585Met mutation. The mortality of ANE caused by COVID-19 was 42%. The use of IVIG in combination with other immunotherapies was related to better outcome (P = 0.041) and both two patients who received Tocilizumab survived. This is the first Chinese case series about ANE associated with COVID-19. Elevated serum and CSF interlukin-6 were found in certain cases. The mortality and morbidity rates remained high although prompt immunotherapy could improve the outcomes.

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.

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

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