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.

Acute necrotizing encephalopathy caused by bacterial infection.

PURPOSE: Acute necrotizing encephalopathy (ANE), a rare and severe brain disorder, is typically linked to prior infections. ANE predominantly affects children, with most reported cases attributed to viral infections. However, instances of bacterial-induced ANE are infrequent. Here, we present a case of adult-onset ANE associated with bacterial infection. CASE DESCRIPTIONS: The patient exhibited a hyperinflammatory state following a urinary tract bacterial infection, with neurological function rapidly declining into a coma as the illness progressed. Gram culture of blood suggested Escherichia coli infection. A magnetic resonance imaging (MRI) scan of the brain showed symmetrical hyperintense lesions involving bilateral thalami and pons in T2-weighted and fluid-attenuated inversion recovery images. These lesions also presented with diffuse cerebral edema and diffusion restriction and subacute hemorrhage. Based on clinical symptoms and typical brain MRI, ANE was diagnosed, and the patient underwent immunotherapy. CONCLUSIONS: This case underscores the occurrence of ANE triggered by bacterial infection, expanding our understanding of the pathogens associated with this condition. It suggests that ANE may be an immune-mediated disorder rather than solely an infectious disease.

Roles of Nucleoporin RanBP2/Nup358 in Acute Necrotizing Encephalopathy Type 1 (ANE1) and Viral Infection.

Ran Binding Protein 2 (RanBP2 or Nucleoporin358) is one of the main components of the cytoplasmic filaments of the nuclear pore complex. Mutations in the RANBP2 gene are associated with acute necrotizing encephalopathy type 1 (ANE1), a rare condition where patients experience a sharp rise in cytokine production in response to viral infection and undergo hyperinflammation, seizures, coma, and a high rate of mortality. Despite this, it remains unclear howRanBP2 and its ANE1-associated mutations contribute to pathology. Mounting evidence has shown that RanBP2 interacts with distinct viruses to regulate viral infection. In addition, RanBP2 may regulate innate immune response pathways. This review summarizes recent advances in our understanding of how mutations in RANBP2 contribute to ANE1 and discusses how RanBP2 interacts with distinct viruses and affects viral infection. Recent findings indicate that RanBP2 might be an important therapeutic target, not only in the suppression of ANE1-driven cytokine storms, but also to combat hyperinflammation in response to viral infections.

Acute hemorrhagic leukoencephalomyelitis in a man with viral myocarditis.

We report a case of acute hemorrhagic leukoencephalomyelitis in a man with viral myocarditis. A 48-year-old previously healthy male was found dead in his locked apartment. At autopsy he was found to be malnourished, and his lungs showed gross evidence of bilateral pneumonia with abscess formation and bullous emphysema. Multiple petechial hemorrhages were observed in the brain and mainly involved white matter in the cerebral hemispheres including the corpus callosum and internal capsule, as well as the cerebellum, brainstem, and spinal cord. Microscopy of the brain and spinal cord revealed perivenular hemorrhages, central microthrombi in venules with fibrin exudation into the subcortical white matter, and early perivenular demyelination associated with scanty mixed cellular infiltrates. Other microscopic features included widespread diffuse viral myocarditis, extensive suppurative bronchopneumonia, and chronic bronchitis. This case illustrates the death of a man with a rare fatal disease associated with two other potentially lethal diseases. The case also illustrates the importance of a holistic approach when determining the cause of death, especially when there are competing causes of death.

Mutations of complement factor I and potential mechanisms of neuroinflammation in acute hemorrhagic leukoencephalitis.

PURPOSE: Acute Hemorrhagic Leukoencephalitis (AHLE) is a rare demyelinating disorder of acute onset, rapid deterioration and significant morbidity and mortality. Most often described as a post-infectious complication of an upper respiratory illness, its precise pathophysiology remains unclear. We describe two pediatric patients with AHLE with partial complement factor I (FI) deficiency whose successful treatment included the interleukin-1 (IL-1) receptor antagonist, anakinra, implicating a role for FI and IL-1 in this disorder. METHODS: Extensive clinical workup of two patients presenting with AHLE revealed complement abnormalities, specifically related to the alternative pathway and its regulator, FI. Aggressive management with steroids, immunoglobulin, and anakinra ultimately led to improvement of clinical status and near return to neurologic baseline in both patients. Genetic sequencing of the FI coding regions of the patients and their families was performed. In vitro protein expression studies and immunohistochemistry of fixed brain tissue was used to investigate pathogenic mechanisms. RESULTS: Two novel mutations in FI were identified in our patients, which result in failure to secrete FI. Immunohistochemical evaluation of brain tissue demonstrated positive staining for C3, membrane attack complex (MAC) and IL-1. CONCLUSIONS: We propose AHLE is an unreported, rare phenotype for partial FI deficiency. The upregulation of C3, MAC and IL-1 with subsequent demyelination support a pathologic role for complement activation in AHLE, and suggest anakinra as an important adjunctive therapy in this disease.

[Acute hemorrhagic leukoencephalitis with a subacute onset]. / Ostryi gemorragicheskii leikoentsefalit Khersta, variant podostrogo techeniya.

Acute hemorrhagic leukoencephalitis (AHLE), also called Hurst's encephalitis, is a rare demyelinating disease of the central nervous system characterized by rapid progression and acute inflammation of the white matter of the brain and spinal cord. AHLE is currently considered as a rare, most severe variant of acute disseminated encephalomyelitis. Clinically AHLE is characterized by a fulminant course with a rapid development of encephalopathy and multifocal neurological symptoms. AHLE is associated with high mortality rate that requires immediate and aggressive treatment initiation. This article describes a case of AHLE with an atypical course, a subacute form, which is extremely rarely described in the literature, with the progressive symptoms' development over several months. Due to delayed treatment initiation, unfortunately, a fatal outcome has been observed. Subsequent histological examination of the autopsy material confirmed the presence of a subacute form of AHLE in the patient.

[Weston-Hurst syndrome. A case report and literature review]. / Síndrome de Weston Hurst. Reporte de un caso y revisión de la literatura.

Background: Acute disseminated encephalomyelitis is an autoimmune and demyelinating disease. It is rare in adults. It has 3 main variants. One of them is Weston-Hurst syndrome, also called acute hemorrhagic leukoencephalitis. The objective was to share the experience in the diagnostic and therapeutic approach of this rare disease, as well as make a review of the current bibliography, in order to collaborate in the knowledge of this disease. Clinical case: 27-year-old woman, with a viral respiratory infection 2 weeks prior to the development of a neurological syndrome characterized by paresthesia, motor deficit, status epilepticus and acute encephalopathy, progressing rapidly to coma, with evidence in MRI of diffuse hemorrhagic lesions in cerebral white matter with demyelination and peripheral edema. It was administered steroid treatment for 5 days, with improvement of symptoms, but with motor and sensory deficits persisting. Conclusion: Acute disseminated encephalomyelitis and its variants are rare entities, with an important range of differential diagnosis, which must be identified and quickly treated to avoid their lethal or disabling outcome.

Introducción: la encefalomielitis aguda diseminada es una enfermedad autoinmune y desmielinizante. Es rara en el adulto. Cuenta con tres variantes principales. Una de ellas es el síndrome de Weston Hurst, también conocido como leucoencefalitis hemorrágica aguda. El objetivo fue compartir la experiencia en el abordaje diagnóstico y terapéutico de esta rara enfermedad, así como hacer una revisión de la bibliografía actual, a fin de colaborar con el conocimiento de esta. Caso clínico: mujer de 27 años con cuadro de infección respiratoria viral 2 semanas previas al desarrollo de síndrome neurológico caracterizado por parestesias, déficit motor, estatus epiléptico y encefalopatía aguda, el cual progresó a estado de coma y evidenció en resonancia magnética lesiones difusas hemorrágicas en sustancia blanca cerebral con desmielinización y edema periférico. Se inició tratamiento con esteroides por 5 días con mejora de síntomas, aunque persistió el déficit motor y sensitivo. Conclusión: la encefalomielitis aguda diseminada y la variante hemorrágica de esta son entidades raras, con una importante gama de diagnóstico diferencial, que deben ser identificadas y tratadas de forma rápida para evitar su letal o incapacitante desenlace.

Acute hemorrhagic leukoencephalitis with severe brainstem and spinal cord involvement: MRI features with neuropathological confirmation.

Acute hemorrhagic leukoencephalitis (AHLE) is a rare and fulminant demyelinating disease considered to be the most severe form of acute disseminated encephalomyelitis (ADEM). A 70-year-old man was admitted to our emergency department (ED) after 1 week of unspecific abdominal symptoms and moderate fever in the first 3 days. Within the ED he developed a rapid onset coma and flaccid tetraparesis. Cerebrospinal fluid (CSF) analysis showed mild polymorphonuclear pleocytosis and magnetic resonance imaging (MRI) revealed supratentorial focal white matter lesions and diffuse involvement of the medulla and spinal cord. A presumptive diagnosis of ADEM was made and the patient was treated with corticosteroids followed by intravenous immunoglobulin. His neurological state did not improve and the MRI on day 8 after admission showed an increased number of lesions, mainly in the brainstem, with hemorrhagic foci. The patient died the following day and pathological features confirmed the diagnosis of AHLE. This is a unique presentation of a rare disease with detailed MRI characteristics and pathological confirmation. Although this condition is usually fatal, early recognition and aggressive therapeutic management can facilitate survival.

Recurrent acute necrotizing encephalopathy in a boy with RANBP2 mutation and thermolabile CPT2 variant: The first case of ANE1 in Japan.

BACKGROUND: Acute necrotizing encephalopathy (ANE) is a severe encephalopathy associated with acute viral infection. While most ANE cases are sporadic, pathogenic variants in the gene RAN binding protein 2 (RANBP2) have been identified as a major cause of familial or recurrent ANE (ANE1). Although sporadic ANE predominantly affects Asian children, ANE1 is very rare in east Asia. CASE REPORT: A 1-year-7-month-old boy, born to unrelated Japanese parents, presented with a seizure and impaired consciousness after 3 days of fever. Brain magnetic resonance imaging (MRI) showed a characteristic involvement of the bilateral thalami, external capsules, insular cortices, and brainstem, suggesting ANE. He received intravenous steroids. Two months later, he had another episode of acute encephalopathy during respiratory syncytial virus infection, from which he recovered relatively well. The recurrent encephalopathic episodes and the characteristic MRI suggested ANE1. Genetic analyses revealed two variants: a rare heterozygous missense variant of RANBP2 [c.1754C>T; p.Thr585Met], and a thermolabile polymorphism in carnitine palmitoyltransferase 2 (CPT2) [c. 1055T>G; p.Phe352Cys]. CONCLUSION: This is the first case of recurrent ANE with an RANBP2 mutation in Japan. The patient also harbored a CPT2 polymorphism that is linked to acute encephalopathy in Japanese patients. Thus, he had a genetic background with two susceptibility variants for acute encephalopathy, RANBP2 (frequent in the Caucasians), and CPT2 (frequent in the Japanese). Further studies are needed to fully discover the genetic predisposition to familial or recurrent ANE in the Asian population.

Acute Disseminated Encephalomyelitis (ADEM): A Demyelinating Disease with Specific Morphological Features.

Acute disseminated encephalomyelitis (ADEM) is a rare immune-mediated inflammatory and demyelinating disorder of the central nervous system. Its characteristic perivenular demyelination and inflammation aid in the differential diagnosis with other inflammatory demyelinating diseases. Here, we present a clinical case of ADEM, summarize its histological hallmarks, and discuss pitfalls concerning the most important neuropathological differential diagnoses.

RANBP2 mutation causing autosomal dominant acute necrotizing encephalopathy attenuates its interaction with COX11.

PURPOSE: Autosomal dominant acute necrotizing encephalopathy (ADANE) is caused by missense mutations in the gene encoding Ran-binding protein 2 (RANBP2), a nuclear pore protein regulating mitochondrial localization and function. Previous studies have found that RANBP2 binds to COX11 and suppresses its inhibitory activity over hexokinase1. To further elucidate mitochondrial dysfunction in ADANE, we analyzed the interaction between mutated RANBP2 and COX11. METHODS: We extracted cDNA from a patient and constructed pGEX wild-type or mutant-type vectors including RANBP2 c.1754C>T, the commonest variant in ADANE. We transformed E. coli competent cells with the vectors and had them express GST-RANBP2 recombinant protein, and conducted a pull-down assay of RANBP2 and COX11. RESULTS: The amount of COX11 bound to mutated RANBP2 was significantly smaller than that bound to the wild-type RANBP2. CONCLUSION: Mutated RANBP2 had an attenuated binding ability to COX11. Whether this change indeed decreases ATP production remains to be further explored.

Atypical acute hemorrhagic leukoencephalitis (Hurst's disease) presenting with focal hemorrhagic brainstem lesion.

BACKGROUND: Acute hemorrhagic leukoencephalitis (AHL; Hurst's disease) is a rare, severe, inflammatory CNS disease that is typically diffuse, multifocal and associated with petechial hemorrhage. The objective of this study is to report the clinical, radiologic, and pathologic findings in a fatal AHL case with focal brainstem involvement and gross hemorrhage. METHODS: Patient evaluation in a tertiary neurointensive care unit with serial brain magnetic resonance imaging (MRI) and neuropathological examination on autopsy were performed. RESULTS: The patient presented with mild, then rapidly worsening, brainstem impairment to a locked-in syndrome. Brain MRI demonstrated an isolated gadolinium enhancing brainstem lesion that enlarged dramatically over weeks and was associated with gross hemorrhage and necrosis. The patient died despite aggressive treatment with intravenous corticosteroids and plasma exchange. Autopsy demonstrated the isolated severe necrotic lesion consistent with AHL. CONCLUSIONS: AHL may present as a solitary brainstem lesion with gross hemorrhage and should be considered in patients with isolated enhancing brainstem lesions. AHL may be fatal even despite early, aggressive immunomodulatory therapy.

Clinical spectrum and prognostic factors of acute necrotizing encephalopathy in children.

This study was conducted to investigate the etiology, the clinical characteristics and prognosis of acute necrotizing encephalopathy (ANE) in Korean children. Six children (1 yr to 7 yr) patients with ANE were enrolled. They were diagnosed by clinical and radiological characteristics and their clinical data were retrospectively analyzed. In a search of clinically plausible causes, brain MRI in all patients, mitochondrial DNA studies for mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes (MELAS) and myoclonus epilepsy and ragged red fibers (MERRF) in four patients, and genomic typing on HLA DRB/HLA DQB genes in three patients were performed. All had precedent illnesses and the main initial symptoms included mental change (83%), seizures (50%), and focal deficits (50%). MRI revealed increased T2 signal density in the bilateral thalami and/or the brainstem in all patients. Mitochodrial DNA studies for MELAS and MERRF were negative in those children and HLA-DRB1*1401, HLA-DRB3*0202, and HLA-DQB1*0502 seemed to be significant. A high dose steroid was given to all patients, which seemed to be partly effective except for 2 patients. In conclusion, ANE is relatively rare, but can result in serious neurological complication in children. Early detection and appropriate treatment may lead to a better neurological outcome.

Acute hemorrhagic leukoencephalitis: a critical entity for forensic pathologists to recognize.

Acute hemorrhagic leukoencephalopathy (AHLE) is a rare, acute disorder characterized by perivenular demyelination and diffuse hemorrhagic necrosis of the central nervous system. AHLE is thought to represent a hyperacute form of acute disseminated encephalomyelitis. AHLE is associated with a greater morbidity and mortality and, fortunately, is much less common than acute disseminated encephalomyelitis. Since most cases of AHLE result in patient demise, forensic pathologists should be cognizant of this entity and consider it in their differential diagnosis.Here we describe an interesting case of a previously healthy 11-year-old boy who initially complained of vague gastroenteritis-like symptoms while visiting a mountain lake. The boy's symptoms evolved to include severe headache and dizziness, necessitating a visit to a rural emergency department. He presented with focal neurologic findings, and head computed tomography (CT) scan confirmed thalamic edema. Cerebrospinal fluid analysis was suggestive of infectious etiology, and multiple empiric therapies were initiated. He was transferred to our institution, and his clinical status continued to worsen. Given the poor prognosis, the family requested withdrawal of supportive care. On day 14 of symptoms the boy succumbed to his illness. An autopsy was requested to further characterize the proximate cause of death.AHLE often presents with abrupt onset of fever, neck stiffness, seizure, and/or focal neurologic signs several days following a viral illness or vaccination. Thus, AHLE can clinically mimic a direct central nervous system infection or a toxic ingestion. AHLE has a very poor prognosis, with rapid deterioration and death usually occurring within days to one week after onset of symptoms. The cause for AHLE is unclear. An autoimmune pathophysiology is likely, with immune cross-reactivity between myelin basic protein moieties and various infectious agent antigens. Treatment for AHLE is not well-established; some authors describe in recent literature that a combination of immunosuppressant medications and/or therapeutic plasma exchange may be of benefit in treating AHLE.

Clinical and Radiologic Findings of Acute Necrotizing Encephalopathy in Young Adults.

Acute necrotizing encephalopathy after an acute febrile illness, although initially described exclusively in the pediatric age group, has been recently shown to have an adult onset as well. In this study, we describe 10 patients (16 years of age or older) with acute necrotizing encephalopathy. In our study, bilateral thalamic involvement with the trilaminar pattern of diffusion restriction on MR imaging was the predominant finding seen in all of the patients reviewed. Ancillary findings of cerebral white matter, brain stem, and cerebellum involvement with sparing of the basal ganglia were also noted. A poorer outcome was observed in patients with a higher degree of thalamic involvement. The cause of an underlying infection was identified in 4 patients (dengue in 3 and influenza in 1). Overall, a sizeable portion of young adults with acute necrotizing encephalopathy have shown a poorer outcome, with dengue being an important underlying trigger in an endemic region.

Quadrigeminal arachnoid cysts in a kitten and a dog.

Two quadrigeminal arachnoid cysts with different pathogenesis are described in 2 different species. A 10-week-old male Persian kitten with a progressively decreasing level of consciousness died spontaneously. At necropsy, mild internal hydrocephalus, caudal cerebellar coning, and cerebellar herniation through the foramen magnum were associated with a congenital quadrigeminal arachnoid cyst compressing the rostral cerebellum and shifting the entire cerebellum caudally. In contrast, a possibly acquired quadrigeminal cyst was observed in a 2-year-old male neutered Yorkshire Terrier in association with necrotizing encephalitis. Quadrigeminal arachnoid cysts have been rarely reported in dogs and humans.

Fulminant acute disseminated encephalomyelitis in children.

Acute disseminated encephalomyelitis (ADEM) is a typically monophasic inflammatory demyelinating disease of the central nervous system with a favorable outcome. However, 2% of ADEM involves acute hemorrhagic leukoencephalitis (AHLE), which is a fulminant and hyperacute variant of ADEM with a poor outcome and high mortality. There are limited case reports of fulminant ADEM including AHLE in children. Herein, we report two pediatric cases of fulminant ADEM. Both cases had a rapid deterioration of consciousness, repetitive seizures, and brain edema on neuroimaging, in addition to atypical neuroradiological findings on magnetic resonance imaging (MRI), a reversible splenial lesion in case 1, and bilateral frontal and occipital cortical lesions in case 2. Both cases were treated with early high-dose methyl-prednisolone and immunoglobulin, while therapeutic hypothermia was also initiated in case 2 after the patient exhibited a decerebrate posture and irregular breathing pattern. Both cases had a favorable outcome. Further case reports on pediatric fulminant ADEM are required to clarify the various clinical types, and to examine the efficacy of various treatment modalities for fulminant ADEM and AHLE in children.

Acute Hemorrhagic Leukoencephalopathy: Pathological Features and Cerebrospinal Fluid Cytokine Profiles.

BACKGROUND: Acute hemorrhagic leukoencephalopathy is a rare encephalopathy of unknown etiology, causing fulminant, hemorrhagic central nervous system demyelination with high mortality. It is unclear whether acute hemorrhagic leukoencephalopathy is an entirely distinct entity from acute disseminated encephalomyelitis. PATIENTS AND METHODS: We report two patients with rapidly progressive neurological illness resulting in raised intracranial pressure and coma, with biopsy-proven acute hemorrhagic leukoencephalopathy (perivascular hemorrhages and demyelination, predominantly neutrophil infiltrates). RESULTS: Acute cerebrospinal fluid showed pronounced T cell-associated cytokine elevation (interleukins 6, 8, and 17A) and CCL2 or CCL3, higher than in patients with acute disseminated encephalomyelitis, but no B cell-associated cytokine elevation. CONCLUSION: Improved understanding of the immune process may provide rationale for use of anticytokine biologic agents.

Acute hemorrhagic demyelination in a murine model of multiple sclerosis.

Acute hemorrhagic leukoencephalomyelitis (AHLE) is a rare neurological condition characterized by the development of acute hemorrhagic demyelination and high mortality. The pathomechanism of AHLE, as well as potential therapeutic approaches, have remained elusive due to the lack of suitable animal models. We report the first murine model of AHLE using a variation of the Theiler's Murine Encephalitis Virus (TMEV) MS model. During acute TMEV infection, C57BL/6 mice do not normally undergo demyelination. However, when 7 day TMEV infected C57BL/6 mice are intravenously administered the immunodominant CD8 T cell peptide, VP2121-130, animals develop characteristics of human AHLE based on pathologic, MRI and clinical features including microhemorrhages, increased blood-brain barrier permeability, and demyelination. The animals also develop severe disability as assessed using the rotarod assay. This study demonstrates the development of hemorrhagic demyelination in TMEV infected C57BL/6 mice within 24 hours of inducing this condition through intravenous administration of CD8 T cell restricted peptide. This study is also the first demonstration of rapid demyelination in a TMEV resistant non-demyelinating strain without transgenic alterations or pharmacologically induced immunosuppression.