Clinical characteristics of Epstein-Barr virus infection in the pediatric nervous system.

BACKGROUND: To investigate the clinical characteristics of Epstein-Barr virus (EBV) infection in the pediatric nervous system (NS). METHODS: We retrospectively analyzed the clinical data and follow-up results of 89 children with neurological damage caused by EBV who were hospitalized in the children's hospital of Chongqing Medical University from January 2008 to April 2019. RESULTS: EBV infection of the NS can occur at any time of the year. The highest incidence was seen in the age group of 0-4 years. Fever is the main clinical feature (74/89, 83.1%). The main clinical types were encephalitis/meningoencephalitis (64/89, 71.9%), acute myelitis (2/89, 2.2%), acute disseminated encephalomyelitis (ADEM) (3/89, 3.4%), Guillain-Barré Syndrome (GBS) (15/89, 16.9%), neurological damage caused by EBV-hemophagocytic lymphohistiocytosis (EBV-HLH) (4/89, 4.5%), and NS-post-transplant lymphoproliferative disorder (NS-PTLD) (1/89, 1.1%). Anti-N-methyl-D-aspartate receptor encephalitis was found during the convalescence of EBV encephalitis. EBV encephalitis/meningitis showed no symptoms of tonsillitis, lymph node enlargement, skin rash, hepatosplenomegaly. Acute motor axonal neuropathy is the chief complication in GBS caused by EBV. CONCLUSION: There were significant differences in neurological complications caused by EBV. The prognosis of EBV infection in the NS is generally good. These illnesses are often self-limiting. A few cases may show residual sequelae.

Potential role of dengue virus, chikungunya virus and Zika virus in neurological diseases.

This study showed that laboratory markers of recent infection by dengue, Zika or chikungunya arboviruses were detected in the biological samples of approximately one-third of patients with encephalitis, myelitis, encephalomyelitis or Guillain-Barré syndrome, in a surveillance programme in Piauí state, Brazil, between 2015-2016. Fever and myalgia had been associated with these cases. Since in non-tropical countries most infections or parainfectious diseases associated with the nervous system are attributed to herpesviruses, enteroviruses, and Campylobacter jejuni, the present findings indicate that in tropical countries, arboviruses may now play a more important role and reinforce the need for their surveillance and systematic investigation in the tropics.

Viral mouse models of multiple sclerosis and epilepsy: Marked differences in neuropathogenesis following infection with two naturally occurring variants of Theiler's virus BeAn strain.

Following intracerebral inoculation, the BeAn 8386 strain of Theiler's virus causes persistent infection and inflammatory demyelinating encephalomyelitis in the spinal cord of T-cell defective SJL/J mice, which is widely used as a model of multiple sclerosis. In contrast, C57BL/6 (B6) mice clear the virus and develop inflammation and lesions in the hippocampus, associated with acute and chronic seizures, representing a novel model of viral encephalitis-induced epilepsy. Here we characterize the geno- and phenotype of two naturally occurring variants of BeAn (BeAn-1 and BeAn-2) that can be used to further understand the viral and host factors involved in the neuropathogenesis in B6 and SJL/J mice. Next generation sequencing disclosed 15 single nucleotide differences between BeAn-1 and BeAn-2, of which 4 are coding changes and 3 are in the 5'-UTR (5'-untranslated region). The relatively minor variations in the nucleotide sequence of the two BeAn substrains led to marked differences in neurovirulence. In SJL/J mice, inflammatory demyelination in the spinal cord and its clinical consequences were significantly more marked following infection with BeAn-1 than with BeAn-2. Both BeAn substrains caused lymphocyte infiltration and increase of MAC3-positive cells in the hippocampus, but hippocampal damage and seizures were only observed in B6 mice. Seizures occurred in one third of BeAn-2 infected B6 mice, but not in BeAn-1 infected B6 mice. By comparing individual mice by receiver operating characteristic (ROC) curve analysis, the severity of hippocampal neurodegeneration and amount of MAC3-positive microglia/macrophages discriminated seizing from non-seizing B6 mice, whereas T-lymphocyte brain infiltration was not found to be a crucial factor. These data add novel evidence to the view that differential outcome of infection may be not invariably linked to a distinct viral burden but to a finely tuned balance between antiviral immune responses that although essential for host resistance can also contribute to immunopathology.

Simultaneous presentation of acute disseminated encephalomyelitis (ADEM) and systemic lupus erythematosus (SLE) after enteroviral infection: can ADEM present as the first manifestation of SLE?

Central Nervous System (CNS) involvement of Systemic Lupus Erythematosus (SLE) includes a broad range of neuropsychiatric syndromes. Acute Disseminated Encephalomyelitis (ADEM) is a demyelinating CNS disorder characterized by encephalopathy and multifocal lesions predominantly involving the white matter on brain magnetic resonance imaging. ADEM associated with SLE has been only rarely reported. We report an unusual case of a 17-year-old girl who developed ADEM after enteroviral infection as the first manifestation of SLE. The authors emphasize that the patient's illness was preceded by enteroviral infection and that ADEM occurred before any other symptoms of SLE, which makes this case unique.

[Severe acute disseminated encephalomyelitis associated with parainfluenza 3 infection: Case report]. / Encefalomielitis aguda diseminada grave: Comunicación de un caso asociado a infección por virus parainfluenza 3.

Disseminated encephalomyelitis (ADEM) is an infrequent condition with considerable morbidity and mortality in adult patients. It requires a high level of suspicion and diagnosis emerges by gathering clinical information, laboratory exams and images studies. ADEM is related to an immunological phenomena occurring after a bacterial/viral infection or recent vaccination. Glucocorticoids are the first line treatment, reserving immunoglobulins and plasmapheresis to refractory cases. We report a male patient aged 25, with ADEM associated to parainfluenza 3 virus respiratory infection that required mechanical ventilation and that had a complete recovery only after plasmapheresis.

Acute disseminated encephalomyelitis in two renal transplant patients: is there a role for Epstein-Barr virus reactivation?

Acute disseminated encephalomyelitis (ADEM) is a rare inflammatory demyelinating disease of the central nervous system, usually occurring after a vaccination or infectious disease. It has been exceptionally described in transplanted patients. The pathophysiology remains incompletely understood. We report the clinical, biological and magnetic resonance imaging (MRI) presentation and evolution of two kidney-transplanted patients with ADEM associated with local Epstein-Barr virus (EBV) reactivation. ADEM may occur in transplanted patients with favorable evolution. Its pathophysiology is uncertain, and the implication of EBV is discussed.

Acute disseminated encephalomyelitis following 2009 H1N1 influenza vaccine.

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated inflammatory disorder of the central nervous system. We describe a previously healthy 2-year-old boy with ADEM, who exhibited high fever, lethargy, and recurrent seizures at 25 days after H1N1 influenza vaccination. To our knowledge, there has been only one report of ADEM following the 2009 H1N1 influenza vaccine, although such vaccination is accompanied with optic neuritis apart from this case. Thus, this is the first case of ADEM without optic neuritis, following the 2009 H1N1 influenza vaccination. Although vaccine-associated ADEM remains rare, the increasing number of influenza vaccinations might increase the incidence of ADEM. We still need to pay attention to the occurrence of ADEM and treat patients with steroid therapy.

[Morphological changes of brain choroid plexuses and ventricle induced by enterovirus infections in monkeys].

The morphological study of monkeys' brains, infected by the Bulgaria strain of enterovirus-71 (EV71), revealed specific for truncus cerebral encephalomyelitis, reactive and destructive changes in different areas of the brainstem and the spinal cord. For the first time viral cytopathology and destruction of choroid plexuses as an important secretory organ of the central nervous system, and ventricle of the brain infected by enterovirus have been studied. The specificity of this infection and the participation of neuroepithelium in reproduction of EV71 have been confirmed by identification of EV71 antigen in the choroid plexuses. According to our data the choroid plexuses take important part in the pathogenesis of EV71 encephalomyelitis. Pathologic changes have been found out in the barriers of CNS. The morphological changes in the brain of monkeys and cotton rats were similar; therefore the last one could be a useful model for different investigations.

Acute disseminated encephalomyelitis associated with Influenza A H1N1 infection.

Previous studies had not suggested acute disseminated encephalomyelitis (ADEM) during Influenza A H1N1 infection. We report the case of patient who had predominant neurological complication following Influenza A H1N1 infection. The patient, who showed clinical and MRI evidence of ADEM, had significant recovery, which in part, may be related to early treatment. The patient demonstrated that the prognosis of Influenza A H1N1-associated ADEM may not be poor.

Post-COVID-19 Acute Disseminated Encephalomyelitis in a 17-Month-Old.

Neurologic manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in pediatric patients have been reported in the acute and postinfectious stages of coronavirus disease 2019. Acute disseminated encephalomyelitis (ADEM) typically presents in children after a viral illness at a mean age of 3 to 7 years. A total of 60% to 90% of literature-reported pediatric patients with ADEM have minimal to no neurologic deficits at long-term follow-up. We present a 17-month-old developmentally typical girl with parental complaints of irritability, upper extremity weakness, and gait disturbance. She presented to the hospital afebrile and irritable with right-sided nasolabial fold flattening, neck stiffness, left upper extremity rigidity, right upper extremity paresis, bilateral lower extremity hyperreflexia, and truncal ataxia. During her hospital course, she became somnolent with autonomic instability and was transferred to intensive care. Contrasted brain MRI revealed diffuse patchy T2 hyperintensities without contrast enhancement. Nasopharyngeal SARS-CoV-2 polymerase chain reaction and serum antibody testing results were positive. Cerebral spinal fluid analysis was unremarkable. Respiratory viral panel and autoimmune encephalitis and demyelinating disorders panel results were negative. She was started on high-dose methylprednisolone and intravenous immunoglobulin, with improvement in mental status, focal deficits, and ambulation. After hospital discharge, she received inpatient rehabilitation for 2 weeks and at 2 month follow-up had a full neurologic recovery. We report the youngest case of postinfectious ADEM due to SARS-CoV-2 in a toddler. Early recognition of autoimmune and inflammatory complications of SARS-CoV-2 is vital for early aggressive immunomodulatory treatment and, consequently, improved morbidity in these patients.

Gist of Zika Virus pathogenesis.

Zika virus (ZIKV) is a mosquito-borne neurotropic flavivirus. ZIKV infection may lead to microcephaly in developing fetus and Guillain-Barré Syndrome (GBS) like symptoms in adults. ZIKV was first reported in humans in 1952 from Uganda and the United Republic of Tanzania. Later, ZIKV outbreak was reported in 2007 from the Yap Island. ZIKV re-emerged as major outbreak in the year 2013 from French Polynesia followed by second outbreak in the year 2015 from Brazil. ZIKV crosses the blood-tissue barriers to enter immune-privileged organs. Clinical manifestations in ZIKV disease includes rash, fever, conjunctivitis, muscle and joint pain, headache, transverse myelitis, meningoencephalitis, Acute Disseminated Encephalomyelitis (ADEM). The understanding of the molecular mechanism of ZIKV pathogenesis is very important to develop potential diagnostic and therapeutic interventions for ZIKV infected patients.

Acute encephalopathy and encephalitis caused by influenza virus infection.

PURPOSE OF REVIEW: Influenza-associated acute encephalopathy/encephalitis (IAE) is an uncommon but serious complication with high mortality and neurological sequelae. This review discusses recent progress in IAE research for a better understanding of the disease features, populations, outcomes, diagnosis, and pathogenesis. RECENT FINDINGS: In recent years, many IAE cases were reported from many countries, including Japan, Canada, Australia, Austria, The Netherlands, United States, Sweden, and other countries and regions. During the novel influenza A/H1N1 pandemic, many IAE cases with A/H1N1 infection in children were reported, particularly in those hospitalized with influenza infection. Pathogenesis of IAE is not fully understood but may involve viral invasion of the CNS, proinflammatory cytokines, metabolic disorders, or genetic susceptibility. An autosomal dominant viral acute necrotizing encephalopathy (ANE) was recently found to have missense mutations in the gene Ran-binding 2 (RANBP2). Another recurrent ANE case following influenza A infection was also reported in a genetically predisposed family with an RANBP2 mutation. SUMMARY: Although IAE is uncommon, compared with the high incidence of influenza infection, it is severe. However, this complication is not duly recognized by health practitioners. Recent advances highlight the threat of this complication, which will help us to have a better understanding of IAE.

Covid-19 systemic infection exacerbates pre-existing acute disseminated encephalomyelitis (ADEM).

Acute disseminated encephalomyelitis (ADEM) is an uncommon diagnosis in adults. It is known to be due to an abnormal immune response to a systemic infection rather than direct viral invasion to the central nervous system. There have been few reports of ADEM diagnosed in the setting of COVID-19 systemic infection. However, we report a case of Coxsackie induced ADEM that remitted but got exacerbated by COVID-19 infection. The patient contracted the COVID-19 infection shortly after being discharged to a rehabilitation facility. Direct COVID-19 neuroinvasion was ruled out via CSF PCR testing for the virus. The patient responded well to pulse steroid therapy and plasmapheresis in both occasions. We hypothesize that COVID-19 infection can flare-up a recently remitted ADEM via altering the immune responses. It is known now that COVID-19 infection can produce cytokine storming. Cytokine pathway activation is known to be involved in the pathology of ADEM. Caution regarding discharging immune suppressed patient to the inpatient rehabilitation facility should be made in the era of COVID-19 pandemic.

COVID-19-associated acute disseminated encephalomyelitis (ADEM).

A 51-year-old woman with COVID-19 infection developed coma and an impaired oculocephalic response to one side. MRI of the brain demonstrated acute multifocal demyelinating lesions, and CSF testing did not identify a direct cerebral infection. High-dose steroids followed by a course of IVIG was administered, and the patient regained consciousness over the course of several weeks. As more patients reach the weeks after initial infection with COVID-19, acute disseminated encephalomyelitis should be considered a potentially treatable cause of profound encephalopathy or multifocal neurological deficits.

Acute disseminated encephalomyelitis (ADEM) associated with COVID-19.

A 53-year-old man admitted to the critical care secondary to respiratory failure due to COVID-19 developed agitation and global hypotonia. Brain MRI revealed bilateral hyperintense lesions throughout the brain and cerebrospinal fluid identified oligoclonal bands. Intravenous high-dose glucocorticoids were administered followed by an oral tapering dose and the patient clinically improved. Acute disseminated encephalomyelitis should be considered in patients with COVID-19 who present with altered mentation and polyfocal neurological deficits.

Acute disseminated encephalomyelitis (ADEM) associated with mosquito-borne diseases: Chikungunya virus X yellow fever immunization.

Acute disseminated encephalomyelitis (ADEM) is a demyelinating autoimmune neuropathic condition characterized by extensive bilateral and confluent lesions in the cerebral white matter and cerebellum. The basal ganglia and gray matter may also be involved. In most cases, the symptoms are preceded by viral infection or vaccination. In this report, we present a case of ADEM associated with optic neuritis presenting alongside two potential triggering factors: chikungunya virus infection and yellow fever immunization.

[Acute disseminated encephalomyelitis in childhood]. / Akut disszeminált encephalomyelitis gyermekkorban.

BACKGROUND AND PURPOSE: Acute disseminated encephalomyelitis is a rare inflammatory demyelinating disorder often preceded by infection or vaccination. The purpose of the study was the systematic analysis of clinical, radiological and microbiological profiles of children treated at Szent László Hospital, and the comparison of findings with literature data. METHODS: Demographic, infectological, clinical, radiological, laboratory and virological data of patients treated and followed-up between 1-Jan-1998 and 30-June-2008 were reviewed and analysed. RESULTS: 19 children met diagnostic criteria. Their mean age was 6.8 years. A prodromal illness--mostly febrile viral infection, upper respiratory infection or chickenpox--preceded neurological symptoms in 17 patients. All had polysymptomatic encephalopathy, 2 children had spinal symptoms. The cerebrospinal fluid was abnormal in all but one. A viral etiology was definite in 7 and probable in 8 cases. MRI disclosed white matter changes in 18, cortical and deep gray matter in 16, cerebellar in 6, brain stem in 14 and spinal cord changes in 2 cases. Repeat MRI performed mean 4 months later showed complete resolution in 6 and partial resolution in 11 patients. 13 patients received high-dose methylprednisolone, 2 of whom were also treated with plasma exchange and 1 with immunoglobulin. 9 children required mechanical ventilation. 2 patients died, 10 recovered without and 7 with sequelae. 2 patients developed further demyelinating events: multiple sclerosis and multiphasic disseminated encephalomyelitis, respectively. CONCLUSION: Clinical, radiological and follow-up results were similar to those published in literature however, triggering viruses were identified in a larger proportion of cases.

Neurotoxic potential of reactive astrocytes in canine distemper demyelinating leukoencephalitis.

Canine distemper virus (CDV) causes a fatal demyelinating leukoencephalitis in young dogs resembling human multiple sclerosis. Astrocytes are the main cellular target of CDV and undergo reactive changes already in pre-demyelinating brain lesions. Based on their broad range of beneficial and detrimental effects in the injured brain reactive astrogliosis is in need of intensive investigation. The aim of the study was to characterize astrocyte plasticity during the course of CDV-induced demyelinating leukoencephalitis by the aid of immunohistochemistry, immunofluorescence and gene expression analysis. Immunohistochemistry revealed the presence of reactive glial fibrillary acidic protein (GFAP)+ astrocytes with increased survivin and reduced aquaporin 4, and glutamine synthetase protein levels, indicating disturbed blood brain barrier function, glutamate homeostasis and astrocyte maladaptation, respectively. Gene expression analysis revealed 81 differentially expressed astrocyte-related genes with a dominance of genes associated with neurotoxic A1-polarized astrocytes. Accordingly, acyl-coA synthetase long-chain family member 5+/GFAP+, and serglycin+/GFAP+ cells, characteristic of A1-astrocytes, were found in demyelinating lesions by immunofluorescence. In addition, gene expression revealed a dysregulation of astrocytic function including disturbed glutamate homeostasis and altered immune function. Observed findings indicate an astrocyte polarization towards a neurotoxic phenotype likely contributing to lesion initiation and progression in canine distemper leukoencephalitis.

Acute disseminated encephalomyelitis: clinical and pathogenesis features.

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated disorder of the central nervous system (CNS). Disease typically starts with an abrupt onset of neurologic symptoms and signs within days to weeks after a viral infection or immunization. Neuropathological examination of the CNS in ADEM reveals involvement of white matter, with infiltration of monocytoid cells and perivenous demyelination.