Acute necrotizing encephalopathy secondary to diphtheria, tetanus toxoid and whole-cell pertussis vaccination: diffusion-weighted imaging and proton MR spectroscopy findings

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.

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.

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.

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.

Influenza-Associated Encephalopathy and Acute Necrotizing Encephalopathy in Children: A Retrospective Single-Center Study

Background

Although influenza primarily affects the respiratory system, it can cause severe neurological complications, especially in younger children, but knowledge about the early indicators of acute necrotizing encephalopathy (ANE) is limited. The main purpose of this article is to summarize the clinical characteristics, diagnosis, and treatment of neurological complications of influenza in children, and to identify factors associated with ANE.

Material/Methods

This was a retrospective study of children with confirmed influenza with neurological complications treated between 01/2014 and 12/2019 at Guangzhou Women and Children’s Medical Center. A receiver operating characteristics curve analysis was performed to determine the prognostic value of selected variables.

Results

Sixty-three children with IAE (n=33) and ANE (n=30) were included. Compared with the IAE group, the ANE group showed higher proportions of fever and acute disturbance of consciousness, higher alanine aminotransferase, higher aspartate aminotransferase, higher creatinine kinase, higher procalcitonin, higher cerebrospinal fluid (CSF) protein, and lower CSF white blood cells (all P<0.05). The areas under the curve (AUCs) for procalcitonin and CSF proteins, used to differentiate IAE and ANE, were 0.790 and 0.736, respectively. The sensitivity and specificity of PCT >4.25 ng/ml to predict ANE were 73.3% and 100.0%, respectively. The sensitivity and specificity of CSF protein >0.48 g/L to predict ANE were 76.7% and 69.7%, respectively. Thirteen (43.3%) children with ANE and none with IAE died (P<0.0001).

Conclusions

High levels of CSF protein and serum procalcitonin might be used as early indicators for ANE. All children admitted with neurological findings, especially during the influenza season, should be evaluated for influenza-related neurological complications.

Brain MR Spectroscopic Findings in 3 Consecutive Patients with COVID-19: Preliminary Observations

Brain multivoxel MR spectroscopic imaging was performed in 3 consecutive patients with coronavirus disease 2019 (COVID-19). These included 1 patient with COVID-19-associated necrotizing leukoencephalopathy, another patient who had a recent pulseless electrical activity cardiac arrest with subtle white matter changes, and a patient without frank encephalopathy or a recent severe hypoxic episode. The MR spectroscopic imaging findings were compared with those of 2 patients with white matter pathology not related to Severe Acute Respiratory Syndrome coronavirus 2 infection and a healthy control subject. The NAA reduction, choline elevation, and glutamate/glutamine elevation found in the patient with COVID-19-associated necrotizing leukoencephalopathy and, to a lesser degree, the patient with COVID-19 postcardiac arrest, follow a similar pattern as seen with the patient with delayed posthypoxic leukoencephalopathy. Lactate elevation was most pronounced in the patient with COVID-19 necrotizing leukoencephalopathy.

Multi-parametric magnetic resonance imaging in acute necrotizing encephalopathy of children: validity and prognostic value

Background

Acute necrotizing encephalopathy of children (ANEC) is a rare fulminant type of acute encephalopathy that mainly occurs in children with a characteristic clinico-radiological pattern. It is commonly preceded by viral infections. The condition carries a poor prognosis with high morbidity and mortality rates. We highlight the relationship between diagnostic multi-parametric magnetic resonance imaging (MRI) findings and correlate them with the clinical outcome of children with ANEC by enrollment of MRI scoring.

Results

The thalami were involved in all 30 patients, brain stem in 80%, basal ganglia (13.3%), cerebral white matter (WM) in 73%, and cerebellar WM in 33%. Hemorrhage was present in 86.7% patients, edema 80%, and necrosis in 13.3%. We found that the patients having the highest MRI scores were in the poor outcome category; whereas the patients with lower MR score (1 or 2) had better outcomes. Statistically positive correlation (r= 0.1198) was found between the multi-parametric MR score and the outcome category.

Conclusion

An extended multi-parametric MRI should be performed in ANEC, allowing early detection and scoring of the disease for better prognosis. There is a positive correlation between the clinical outcome and the MR scoring.

Genetic Acute Necrotizing Encephalopathy Associated with RANBP2: Clinical and Therapeutic Implications in Pediatrics

Genetic (also known as familial) acute necrotizing encephalopathy (ANE1) is a rare disease presenting with encephalopathy often following preceding viral febrile illness in patients with a genetic predisposition resulting from a missense mutation in the gene encoding RAN Binding Protein 2 (RANBP2). The acute episode is characterized by deterioration in consciousness, often with focal neurologic deficits and seizures. Additionally, symmetric multifocal brain lesions are seen in the bilateral thalami as well as other characteristic regions, involving both gray and white matter. Prognosis is variable, with a high mortality rate and most surviving patients having persistent neurologic deficits. Early treatment with high dose steroids is associated with a more favorable outcome, however the diagnosis is often overlooked resulting in delayed treatment. The RANBP2 mutation associated with ANE1 causes an incompletely penetrant predisposition to encephalopathy in the setting of febrile illness through a mechanism that remains elusive. There are several non-mutually exclusive hypotheses suggesting possible etiologies for this phenotype based on the many functions of RANBP2 within the cell. These include dysfunctions in nucleocytoplasmic trafficking and intracellular metabolic regulation, as well as cytokine storm, and abnormal distribution of mitochondria. This narrative review explores these key concepts of the RANBP2 mutation and its clinical and therapeutic implications in pediatric populations.

Acute Necrotizing Encephalopathy in Children: a Long Way to Go

BACKGROUND

Acute necrotizing encephalopathy (ANE) is a rare, but potentially life threatening neurological condition in children. This study aimed to investigate its clinical spectrum, diagnostic and therapeutic dilemma, and prognosis.

METHODS

Twelve children with ANE were included in the study. The diagnosis was made by clinical and radiological characteristics from January 1999 to December 2017 and their clinical data were retrospectively analyzed.

RESULTS

A total of 12 children aged 6 to 93 months at onset (5 male: 7 female) were evaluated. The etiology was found in 4 of them (influenza A, H1N1; coxsackie A 16; herpes simplex virus; and RANBP2 gene/mycoplasma). The most common initial presentations were seizures (67%) and altered mental status (58%). The majority of the subjects showed elevation of aspartate aminotransferase/alanine aminotransferase with normal ammonia and increased cerebrospinal fluid protein without pleocytosis. Magnetic resonance imaging revealed increased T2 signal density in bilateral thalami in all patients, but the majority of the subjects (67%) also had lesions in other areas including tegmentum and white matter. Despite the aggressive immunomodulatory treatments, the long-term outcome was variable. One child and two sisters with genetic predisposition passed away.

CONCLUSION

ANE is a distinctive type of acute encephalopathy with diverse clinical spectrum. Even though the diagnostic criteria are available, they might not be watertight. In addition, treatment options are still limited. Further studies for better outcome are needed.

Optic neuritis following diphtheria, tetanus, pertussis, and inactivated poliovirus combined vaccination: a case report

Background

Diphtheria, tetanus, pertussis, and inactivated poliovirus combined vaccine is widely used in young children as part of a series of immunizations before they start attending school. Case studies of demyelinating conditions following administration of diphtheria, tetanus, pertussis, and polio vaccine have been reported, but none so far resulting in optic neuritis. This report further contributes to the database of central nervous system demyelinating conditions affiliated with receipt of vaccines.

Case presentation

A previously healthy 27-year-old Hispanic man presented to an emergency department with headache, periorbital pressure, pain with ocular movements, and intermittent blurred vision that developed 1 day after administration of the diphtheria, tetanus, pertussis, and inactivated poliovirus combined vaccine. A diagnosis of optic neuritis was made via ophthalmic examination with fundus photography and automated Humphrey visual field analysis. His vision recovered following treatment with high-dose intravenously administered methylprednisolone followed by a tapered dose of orally administered prednisolone.

Conclusions

Although the association between immunizations and the onset of central nervous system demyelinating conditions is well documented, this report, to the best of our knowledge, is the first case of optic neuritis following diphtheria, tetanus, pertussis, and inactivated poliovirus combined vaccination. Inclusion of this case report in the medical community will allow for broader understanding of possible conditions that may present shortly after receipt of vaccination.

Vaccine-associated inflammatory diseases of the central nervous system: from signals to causation

PURPOSE OF REVIEW

As the most cost-effective intervention in preventive medicine and as a crucial element of any public health program, vaccination is used extensively with over 90% coverage in many countries. As approximately 5-8% of the population in developed countries suffer from an autoimmune disorder, people with an autoimmune disease are most likely to be exposed to some vaccines before or after the disease onset. In fact, a number of inflammatory disorders of the central nervous system have been associated with the administration of various vaccines. These adverse events, be they spurious associations or genuine reactions to the vaccine, may lead to difficulties in obtaining public trust in mass vaccination programs. There is, thus, an urgent need to understand whether vaccination triggers or enhances autoimmune responses.

RECENT FINDINGS

By reviewing vaccine-associated inflammatory diseases of the central nervous system, this study describes the current knowledge on whether the safety signal was coincidental, as in the case of multiple sclerosis with several vaccines, or truly reflected a causal link, as in narcolepsy with cataplexy following pandemic H1N1 influenza virus vaccination.

SUMMARY

The lessons learnt emphasize a central role of thorough, ideally prospective, epidemiological studies followed, if the signal is deemed plausible or real, by immunological investigations.

Acute necrotising encephalopathy in a child with H1N1 influenza infection: a clinicoradiological diagnosis and follow-up

Acute necrotising encephalopathy of childhood (ANEC) is a fulminant disorder with rapid progressive encephalopathy, seizures and poor outcome. It has been reported in association with various viral infections. We describe the clinicoradiological findings and short-term follow-up in a child with H1N1 influenza-associated ANEC. Laminar, target or tricolour pattern of involvement of the thalami was seen on apparent diffusion coefficient images. Our patient had significant morbidity at discharge despite early diagnosis and management with oseltamivir and immunoglobulin. Repeat imaging after 3 months had shown significant resolution of thalamic swelling, but there was persistence of cytotoxic oedema involving bilateral thalami. She was pulsed with intravenous steroids and maintained on a tapering schedule of oral steroids. This report emphasises the need for a high index of suspicion to establish early diagnosis, promotion of widespread immunisation strategies to prevent influenza outbreak, and more research to establish standard treatment protocols for this under-recognised entity.

Acute necrotizing encephalopathy: an underrecognized clinicoradiologic disorder

Acute necrotizing encephalopathy (ANE) is a rare but distinctive type of acute encephalopathy with global distribution. Occurrence of ANE is usually preceded by a virus-associated febrile illness and ensued by rapid deterioration. However, the causal relationship between viral infections and ANE and the exact pathogenesis of ANE remain unclear; both environmental and host factors might be involved. Most cases of ANE are sporadic and nonrecurrent, namely, isolated or sporadic ANE; however, few cases are recurrent and with familial episodes. The recurrent and familial forms of ANE were found to be incompletely autosomal-dominant. Further the missense mutations in the gene encoding the nuclear pore protein Ran Binding Protein 2 (RANBP2) were identified. Although the clinical course and the prognosis of ANE are diverse, the hallmark of neuroradiologic manifestation of ANE is multifocal symmetric brain lesions which are demonstrated by computed tomography (CT) or magnetic resonance imaging (MRI). The treatment of ANE is still under investigation. We summarize the up-to-date knowledge on ANE, with emphasis on prompt diagnosis and better treatment of this rare but fatal disease.

Aluminum in the central nervous system (CNS): toxicity in humans and animals, vaccine adjuvants, and autoimmunity

We have examined the neurotoxicity of aluminum in humans and animals under various conditions, following different routes of administration, and provide an overview of the various associated disease states. The literature demonstrates clearly negative impacts of aluminum on the nervous system across the age span. In adults, aluminum exposure can lead to apparently age-related neurological deficits resembling Alzheimer's and has been linked to this disease and to the Guamanian variant, ALS-PDC. Similar outcomes have been found in animal models. In addition, injection of aluminum adjuvants in an attempt to model Gulf War syndrome and associated neurological deficits leads to an ALS phenotype in young male mice. In young children, a highly significant correlation exists between the number of pediatric aluminum-adjuvanted vaccines administered and the rate of autism spectrum disorders. Many of the features of aluminum-induced neurotoxicity may arise, in part, from autoimmune reactions, as part of the ASIA syndrome.

Nuclear magnetic resonance spectroscopy is highly sensitive for lipid-soluble metabolites

Although the water-soluble metabolite profile of human mesenchymal stem cells is known, the lipid profile still needs further investigation. In this study, methanol-chloroform was used to extract pid-soluble metabolites and perchloric acid was used to extract water-soluble metabolites. Furthermore, a dual phase extraction method using methanol-chloroform and water was used to obtain both water and lipid fractions simultaneously. All metabolite extractions were analyzed on a 9.4T high-resolution nuclear magnetic resonance spectrometer. Metabolite resonance peaks were assigned in the acquired spectra according to the chemical shift, and the extraction efficiency of ferent methods was compared. Results showed that in the spectra of water-soluble extracts, major metabolites comprised low molecular weight metabolites, including lactate, acetic acid, fatty acids, threonine, glutamic acid, creatine, choline and its derivatives, while in the spectra of lipid-soluble extracts, most metabolites were assigned to fatty acids. Among the different extraction procedures, perchloric acid was more efficient in extracting water-soluble metabolites and methanol-chloroform was efficient in extracting organic components compared with the dual phase extraction method. Nuclear magnetic resonance spectroscopy showed that as low as 0.7 mg organic yield was enough to obtain clear resonance peaks, while about 6.0 mg water-soluble yield was needed to obtain relatively favorable spectral lines. These results show that the efficiency of extracting water and lipid fractions is higher using perchloric acid and methanol-chloroform compared with dual phase extraction and that nuclear magnetic resonance spectroscopy is highly sensitive for analyzing lipid-soluble extracts.

The interplay of infection and genetics in acute necrotizing encephalopathy

PURPOSE OF REVIEW

Acute necrotizing encephalopathy (ANE) presents with fulminant encephalopathy and characteristic brain lesions following viral infection. The rarity and unpredictability of the disorder have significantly impaired its study. Growing recognition of ANE and the discovery of causative missense mutations in the nuclear pore gene RANBP2 give promising steps toward unraveling this disease. This review summarizes recent advances of clinical and scientific understanding of ANE.

RECENT FINDINGS

Inflammatory factors participate in the pathogenesis of ANE, but the lack of difference between influenza and noninfluenza ANE focuses attention on the abnormal host response as causative. Early treatment with steroids provides the best outcome for patients who do not have brainstem lesions. Missense mutations in RANBP2 cause the majority of familial and recurrent ANE cases, but other single-gene causes of ANE are possible for familial, recurrent, and sporadic cases.

SUMMARY

Early recognition and systematic evaluation of ANE are necessary. Modeling ANE as a genetic disorder may provide the most immediate gains in the understanding and treatment of ANE and related disorders.