Interferon regulatory factors 3 and 7 have distinct roles in the pathogenesis of alphavirus encephalomyelitis.

Interferon (IFN) regulatory factors (IRFs) are important determinants of the innate response to infection. We evaluated the role(s) of combined and individual IRF deficiencies in the outcome of infection of C57BL/6 mice with Sindbis virus, an alphavirus that infects neurons and causes encephalomyelitis. The brain and spinal cord levels of Irf7, but not Irf3 mRNAs, were increased after infection. IRF3/5/7-/- and IRF3/7-/- mice died within 3-4 days with uncontrolled virus replication, similar to IFNα receptor-deficient mice, while all wild-type (WT) mice recovered. IRF3-/- and IRF7-/- mice had brain levels of IFNα that were lower, but brain and spinal cord levels of IFNß and IFN-stimulated gene mRNAs that were similar to or higher than WT mice without detectable serum IFN or increases in Ifna or Ifnb mRNAs in the lymph nodes, indicating that the differences in outcome were not due to deficiencies in the central nervous system (CNS) type I IFN response. IRF3-/- mice developed persistent neurological deficits and had more spinal cord inflammation and higher CNS levels of Il1b and Ifnγ mRNAs than WT mice, but all mice survived. IRF7-/- mice died 5-8 days after infection with rapidly progressive paralysis and differed from both WT and IRF3-/- mice in the induction of higher CNS levels of IFNß, tumour necrosis factor (TNF) α and Cxcl13 mRNA, delayed virus clearance and more extensive cell death. Therefore, fatal disease in IRF7-/- mice is likely due to immune-mediated neurotoxicity associated with failure to regulate the production of inflammatory cytokines such as TNFα in the CNS.

MOG antibody-associated encephalomyelitis/encephalitis.

Myelin oligodendrocyte glycoprotein (MOG) antibody disease is a rare autoimmune disorder with antibodies against the MOG predominantly involving the optic nerve and spinal cord leading to vision loss and paralysis. When MOG antibody disease involves the brain, the phenotype is similar to acute disseminated encephalomyelitis (ADEM). In this review, we discuss MOG-positive cases presenting with encephalitis, encephalopathy, or ADEM-like presentation based on recently published series.

Clinical and immunological characteristics of the spectrum of GFAP autoimmunity: a case series of 22 patients.

OBJECTIVE: To report the clinical and immunological characteristics of 22 new patients with glial fibrillar acidic protein (GFAP) autoantibodies. METHODS: From January 2012 to March 2017, we recruited 451 patients with suspected neurological autoimmune disease at the Catholic University of Rome. Patients' serum and cerebrospinal fluid (CSF) samples were tested for neural autoantibodies by immunohistochemistry on mouse and rat brain sections, by cell-based assays (CBA) and immunoblot. GFAP autoantibodies were detected by immunohistochemistry and their specificity confirmed by CBA using cells expressing human GFAPα and GFAPδ proteins, by immunoblot and immunohistochemistry on GFAP-/- mouse brain sections. RESULTS: Serum and/or CSF IgG of 22/451 (5%) patients bound to human GFAP, of which 22/22 bound to GFAPα, 14/22 to both GFAPα and GFAPδ and none to the GFAPδ isoform only. The neurological presentation was: meningoencephalomyelitis or encephalitis in 10, movement disorder (choreoathetosis or myoclonus) in 3, anti-epileptic drugs (AED)-resistant epilepsy in 3, cerebellar ataxia in 3, myelitis in 2, optic neuritis in 1 patient. Coexisting neural autoantibodies were detected in five patients. Six patients had other autoimmune diseases. Tumours were found in 3/22 patients (breast carcinoma, 1; ovarian carcinoma, 1; thymoma, 1). Nineteen patients were treated with immunotherapy and 16 patients (84%) improved. Histopathology analysis of the leptomeningeal biopsy specimen from one patient revealed a mononuclear infiltrate with macrophages and CD8+ T cells. CONCLUSIONS: GFAP autoimmunity is not rare. The clinical spectrum encompasses meningoencephalitis, myelitis, movement disorders, epilepsy and cerebellar ataxia. Coexisting neurological and systemic autoimmunity are relatively common. Immunotherapy is beneficial in most cases.

Children with multiphasic disseminated encephalomyelitis and antibodies to the myelin oligodendrocyte glycoprotein (MOG): Extending the spectrum of MOG antibody positive diseases.

BACKGROUND: Myelin oligodendrocyte glycoprotein (MOG) antibodies have been described in children with acute disseminated encephalomyelitis (ADEM), recurrent optic neuritis, neuromyelitis optica spectrum disorders and more recently in children with multiphasic disseminated encephalomyelitis (MDEM). OBJECTIVE: To delineate the clinical, cerebrospinal fluid (CSF) and radiological features of paediatric MDEM with MOG antibodies. METHODS: Clinical course, serum antibodies, CSF, magnetic resonance imaging (MRI) studies and outcome of paediatric MDEM patients were reviewed. RESULTS: A total of 8 children with two or more episodes of ADEM were identified from a cohort of 295 children with acute demyelinating events. All children had persisting MOG antibodies (median titre: 1:1280). All ADEM episodes included encephalopathy, polyfocal neurological signs and a typical MRI. Apart from ADEM episodes, three children had further clinical attacks without encephalopathy. Median age at initial presentation was 3 years (range: 1-7 years) and median follow-up 4 years (range: 1-8 years). New ADEM episodes were associated with new neurological signs and new MRI lesions. Clinical outcome did range from normal (four of the eight) to mild or moderate impairment (four of the eight). A total of four children received monthly immunoglobulin treatment during the disease course. CONCLUSION: Children with MDEM and persisting MOG antibodies constitute a distinct entity of relapsing demyelinating events and extend the spectrum of MOG antibody-associated diseases.

Glycine receptor antibodies in PERM and related syndromes: characteristics, clinical features and outcomes.

The clinical associations of glycine receptor antibodies have not yet been described fully. We identified prospectively 52 antibody-positive patients and collated their clinical features, investigations and immunotherapy responses. Serum glycine receptor antibody endpoint titres ranged from 1:20 to 1:60 000. In 11 paired samples, serum levels were higher than (n = 10) or equal to (n = 1) cerebrospinal fluid levels; there was intrathecal synthesis of glycine receptor antibodies in each of the six pairs available for detailed study. Four patients also had high glutamic acid decarboxylase antibodies (>1000 U/ml), and one had high voltage-gated potassium channel-complex antibody (2442 pM). Seven patients with very low titres (<1:50) and unknown or alternative diagnoses were excluded from further study. Three of the remaining 45 patients had newly-identified thymomas and one had a lymphoma. Thirty-three patients were classified as progressive encephalomyelitis with rigidity and myoclonus, and two as stiff person syndrome; five had a limbic encephalitis or epileptic encephalopathy, two had brainstem features mainly, two had demyelinating optic neuropathies and one had an unclear diagnosis. Four patients (9%) died during the acute disease, but most showed marked improvement with immunotherapies. At most recent follow-up, (2-7 years, median 3 years, since first antibody detection), the median modified Rankin scale scores (excluding the four deaths) decreased from 5 at maximal severity to 1 (P < 0.0001), but relapses have occurred in five patients and a proportion are on reducing steroids or other maintenance immunotherapies as well as symptomatic treatments. The glycine receptor antibodies activated complement on glycine receptor-transfected human embryonic kidney cells at room temperature, and caused internalization and lysosomal degradation of the glycine receptors at 37°C. Immunoglobulin G antibodies bound to rodent spinal cord and brainstem co-localizing with monoclonal antibodies to glycine receptor-α1. Ten glycine receptor antibody positive samples were also identified in a retrospective cohort of 56 patients with stiff person syndrome and related syndromes. Glycine receptor antibodies are strongly associated with spinal and brainstem disorders, and the majority of patients have progressive encephalomyelitis with rigidity and myoclonus. The antibodies demonstrate in vitro evidence of pathogenicity and the patients respond well to immunotherapies, contrasting with earlier studies of this syndrome, which indicated a poor prognosis. The presence of glycine receptor antibodies should help to identify a disease that responds to immunotherapies, but these treatments may need to be sustained, relapses can occur and maintenance immunosuppression may be required.

Pathogenic T cell responses against aquaporin 4.

Inflammatory lesions in the central nervous system of patients with neuromyelitis optica are characterized by infiltration of T cells and deposition of aquaporin-4-specific antibodies and complement on astrocytes at the glia limitans. Although the contribution of aquaporin-4-specific autoantibodies to the disease process has been recently elucidated, a potential role of aquaporin-4-specific T cells in lesion formation is unresolved. To address this issue, we raised aquaporin-4-specific T cell lines in Lewis rats and characterized their pathogenic potential in the presence and absence of aquaporin-4-specific autoantibodies of neuromyelitis optica patients. We show that aquaporin-4-specific T cells induce brain inflammation with particular targeting of the astrocytic glia limitans and permit the entry of pathogenic anti-aquaporin-4-specific antibodies to induce NMO-like lesions in spinal cord and brain. In addition, transfer of aquaporin-4-specific T cells provoked mild (subclinical) myositis and interstitial nephritis. We further show that the expression of the conformational epitope, recognized by NMO patient-derived aquaporin-4-specific antibodies is induced in kidney cells by the pro-inflammatory cytokine gamma-interferon. Our data provide further support for the view that NMO lesions may be induced by a complex interplay of T cell mediated and humoral immune responses against aquaporin-4.

Autoimmune Glial Fibrillary Acidic Protein Astrocytopathy in Children: A Retrospective Analysis of 35 Cases.

Objective: To analyze the clinical manifestations, imaging, electroencephalography, treatment, and prognosis of 35 cases of autoimmune glial fibrillary acidic protein astrocytopathy (GFAP-A) in children. Methods: Children hospitalized in the Department of Neurology, Hunan Children's Hospital, China, between January 2015 and June 2021, owing to autoimmune diseases of the central nervous system were subjected to a cell-based assay (CBA). The assay identified 40 children positive for GFAP-immunoglobulin (Ig)G antibodies in the serum and/or the cerebrospinal fluid. Based on clinical manifestations and imaging characteristics, five children who were only positive for GFAP-IgG antibodies in serum were excluded, and the remaining 35 children were diagnosed with autoimmune GFAP-A. The clinical data derived from the 35 children were retrospectively analyzed. Results: A total of 35 children, including 23 males and 12 females with a mean age of 6.3 ± 0.6 years, manifested clinical symptoms of fever (62.9%), headache (42.9%), convulsions (42.9%), abnormal mental behavior (51.4%), disorders of consciousness (54.3%), visual disturbance (22.9%), ataxia (11.4%), paralysis (40%), and autonomic dysfunction (25.7%). One child exhibited only the clinical symptom of peripheral facial nerve palsy. Eleven out of 35 children were also positive for other antibodies. In addition to the common overlapping autoimmune syndromes, one case of autoimmune GFAP-A also manifested as Bickerstaff's brainstem encephalitis. Linear periventricular enhancement upon MRI was significantly less frequent in children (8.5%) than in adults. In pediatric patients, MRI contrast enhancement was principally seen in the meninges and brain lobes. Although repeated relapse (17.1%) and sequelae symptoms (20%) occurred in some cases, most children showed a favorable prognosis. Spearman's rank correlation showed that the antibody titer was not significantly associated with the severity of the initial disease conditions. Conclusions: The disease diagnosis in children seropositive for GFAP antibodies only should receive a comprehensive diagnosis based on their clinical symptoms, imaging, electroencephalographic characteristics, and treatment responses. Some patients with relapses should receive repeated gamma globulin and corticosteroid therapy or the addition of immunosuppressants to their therapeutic regimen, and slow-dose tapering of corticosteroids and extended treatment are recommended for patients with overlapping autoimmune syndromes.

Inflammation and central nervous system Lyme disease.

Lyme disease, caused by the bacterium Borrelia burgdorferi, can cause multi-systemic signs and symptoms, including peripheral and central nervous system disease. This review examines the evidence for and mechanisms of inflammation in neurologic Lyme disease, with a specific focus on the central nervous system, drawing upon human studies and controlled research with experimentally infected rhesus monkeys. Directions for future human research are suggested that may help to clarify the role of inflammation as a mediator of the chronic persistent symptoms experienced by some patients despite antibiotic treatment for neurologic Lyme disease.

Vaccination with DNA encoding an immunodominant myelin basic protein peptide targeted to Fc of immunoglobulin G suppresses experimental autoimmune encephalomyelitis.

We explore here if vaccination with DNA encoding an autoantigenic peptide can suppress autoimmune disease. For this purpose we used experimental autoimmune encephalomyelitis (EAE), which is an autoaggressive disease in the central nervous system and an animal model for multiple sclerosis. Lewis rats were vaccinated with DNA encoding an encephalitogenic T cell epitope, guinea pig myelin basic protein peptide 68-85 (MBP68-85), before induction of EAE with MBP68-85 in complete Freund's adjuvant. Compared to vaccination with a control DNA construct, the vaccination suppressed clinical and histopathological signs of EAE, and reduced the interferon gamma production after challenge with MBP68-85. Targeting of the gene product to Fc of IgG was essential for this effect. There were no signs of a Th2 cytokine bias. Our data suggest that DNA vaccines encoding autoantigenic peptides may be useful tools in controlling autoimmune disease.

Upregulation and coexpression of adhesion molecules correlate with relapsing autoimmune demyelination in the central nervous system.

The expression of adhesion molecules on central nervous system (CNS) vessels was examined during chronic relapsing experimental autoimmune encephalomyelitis in the SJL mouse. Two molecules associated with cell adhesion were studied: MECA-325, a murine lymph node high endothelial venule marker; and MALA-2, the murine homologue of intercellular adhesion molecule 1. During initial disease, upregulated coexpression of these two molecules occurred in the CNS. This correlated with inflammatory cell invasion. During remission, expression was downregulated, and each subsequent relapse was accompanied by corresponding upregulation. Thus, up- and downregulation of adhesion molecules in the target organ appeared to form an integral part of the inflammatory process in this autoimmune condition and support a role for receptor-mediated inflammatory cell invasion of relevance to the pathogenesis of multiple sclerosis.

Epidemiology of Viliuisk encephalomyelitis in Eastern Siberia.

BACKGROUND: Viliuisk encephalomyelitis is a disorder that starts, in most cases, as an acute meningoencephalitis. Survivors of the acute phase develop a slowly progressing neurologic syndrome characterized by dementia, dysarthria, and spasticity. An epidemic of this disease has been spreading throughout the Yakut Republic of the Russian Federation. Although clinical, neuropathologic, and epidemiologic data suggest infectious etiology, multiple attempts at pathogen isolation have been unsuccessful. METHODS: Detailed clinical, pathologic, laboratory, and epidemiologic studies have identified 414 patients with definite Viliuisk encephalomyelitis in 15 of 33 administrative regions of the Yakut Republic between 1940 and 1999. All data are documented in a Registry. RESULTS: The average annual Viliuisk encephalomyelitis incidence rate at the height of the epidemic reached 8.8 per 100,000 population and affected predominantly young adults. The initial outbreak occurred in a remote isolated area of the middle reaches of Viliui River; the disease spread to adjacent areas and further in the direction of more densely populated regions. The results suggest that intensified human migration from endemic villages led to the emergence of this disease in new communities. Recent social and demographic changes have presumably contributed to a subsequent decline in disease incidence. CONCLUSIONS: Based on the largest known set of diagnostically verified Viliuisk encephalomyelitis cases, we demonstrate how a previously little-known disease that was endemic in a small indigenous population subsequently reached densely populated areas and produced an epidemic involving hundreds of persons.

Autoimmune glial fibillary acidic protein astrocytopathy associated meningoencephalomyelitis and bilateral sensorineuronal deafness.

Autoimmune encephalitis is an important group of disease that can mimic infectious encephalitis, with one of the most severe forms being meningoencephalomyelitis. One of the recently identified biomarkers, glial fibillary acidic protein (GFAP), targets the cytosolic intermediate filament protein of astrocytes and causes a variety of clinical symptoms. Here, we report an adult Chinese woman presented with acute onset of confusion, CSF lymphocytosis, markedly elevated total protein mimicking tuberculosis meningitis with rapid deterioration resulted in coma and respiratory failure. She was diagnosed with anti-GFAP meningoencephalomyelitis, which later developed tetraplegia, sensorineural hearing loss, brainstem, bulbar and respiratory dysfunction. Intravenous immunoglobulin and methylprednisolone resulted in partial improvement. Further immunotherapy with plasma exchange and rituximab resulted in marked recovery.

Elevated Perceived Exertion in People with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Fibromyalgia: A Meta-analysis.

PURPOSE: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia (FM) are two debilitating illnesses primarily characterized by chronic symptoms of fatigue and musculoskeletal pain, respectively. Some investigators have observed an elevated sense of effort in these patient groups; however, this effect has not been substantiated via quantitative review. As such, we conducted a meta-analysis of RPE responses to aerobic exercise in ME/CFS and FM compared with healthy adults. METHODS: Case-control studies involving adults with ME/CFS or FM that measured RPE and heart rate responses to acute aerobic exercise were included. Data sources included PubMed, Scopus/Embase, CINAHL, CENTRAL, and Google Scholar. Risk of bias was assessed by evaluating each study's description of participant characteristics, matching procedures, and administration of RPE scales. Hedges' d effect sizes for RPE were calculated and aggregated using random-effects models, and potential moderators were explored with meta-regression analysis. RESULTS: Forty-one effects were extracted from 37 studies involving 1016 patients and 686 healthy controls. We observed a large (Hedges' d = 0.85, 95% confidence interval = 0.62-1.08) effect indicating higher RPE in patients than controls. The mean effect size was significantly moderated (P < 0.001, R = 0.38) by whether RPE data were analyzed at a peak or submaximal intensity (b = 0.60, z = 4.6, P < 0.001) and the type of patient group that was studied (b = 0.25, z = 2.08, P = 0.04). CONCLUSIONS: People with ME/CFS and FM perceive aerobic exercise as more effortful than healthy adults, but the exact causes are unclear. The large magnitude of this effect merits further exploration of underlying mechanisms that could provide insight into the pathophysiology of ME/CFS and FM or the broader debate about the nature of central and/or peripheral signals that influence RPE.

Viliuisk encephalomyelitis in Eastern Siberia - analysis of 390 cases.

Viliuisk encephalomyelitis (VE) is a unique disease occurring in the Yakut (Sakha) population of Eastern Siberia. VE is always fatal, with some patients dying during the acute encephalitic phase of illness; those surviving the acute phase develop progressive dementia, rigidity and spastic quadriparesis as part of a more prolonged pan-encephalitic syndrome. The disease is characterized neuropathologically by multiple widespread micronecrotic foci with marked inflammatory reactions and subsequent gliosis throughout the cerebral cortex, basal ganglia, cerebellum and brain stem. The acute febrile onset with cerebrospinal fluid pleocytosis and increased protein and neuropathology showing inflammatory reactions suggest that VE is an infectious disease, but the causative agent has not been identified. Initially detected in a small mixed Yakut-Evenk population of the mid-Viliui region, the disease subsequently spread south to densely populated areas around the capital city of Yakutsk. The occurrence of secondary VE cases in households and the introduction of the disease by migrants into new populations indicate that the disease is horizontally transmitted in a setting of a long intra-household contact. Although there has been a recent decline in the number of cases, increasing travel may result in further spread of this fatal disease to susceptible individuals in other regions of the world.

Evidence of altered cardiac autonomic regulation in myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review and meta-analysis.

BACKGROUND: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex condition with no reliable diagnostic biomarkers. Studies have shown evidence of autonomic dysfunction in patients with ME/CFS, but results have been equivocal. Heart rate (HR) parameters can reflect changes in autonomic function in healthy individuals; however, this has not been thoroughly evaluated in ME/CFS. METHODS: A systematic database search for case-control literature was performed. Meta-analysis was performed to determine differences in HR parameters between ME/CFS patients and controls. RESULTS: Sixty-four articles were included in the systematic review. HR parameters assessed in ME/CFS patients and controls were grouped into ten categories: resting HR (RHR), maximal HR (HRmax), HR during submaximal exercise, HR response to head-up tilt testing (HRtilt), resting HR variability (HRVrest), HR variability during head-up tilt testing (HRVtilt), orthostatic HR response (HROR), HR during mental task(s) (HRmentaltask), daily average HR (HRdailyaverage), and HR recovery (HRR) Meta-analysis revealed RHR (MD ±â€Š95% CI = 4.14 ±â€Š1.38, P < .001), HRtilt (SMD ±â€Š95% CI = 0.92 ±â€Š0.24, P < .001), HROR (0.50 ±â€Š0.27, P < .001), and the ratio of low frequency power to high frequency power of HRVrest (0.39 ±â€Š0.22, P < .001) were higher in ME/CFS patients compared to controls, while HRmax (MD ±â€Š95% CI = -13.81 ±â€Š4.15, P < .001), HR at anaerobic threshold (SMD ±â€Š95% CI = -0.44 ±â€Š0.30, P = 0.005) and the high frequency portion of HRVrest (-0.34 ±â€Š0.22, P = .002) were lower in ME/CFS patients. CONCLUSIONS: The differences in HR parameters identified by the meta-analysis indicate that ME/CFS patients have altered autonomic cardiac regulation when compared to healthy controls. These alterations in HR parameters may be symptomatic of the condition.

Cerebrospinal Fluid Neopterin in Children With Enterovirus-Related Brainstem Encephalitis.

BACKGROUND: Enterovirus-A71 causes outbreaks of brainstem encephalitis, ranging from self-limited disease to acute flaccid paralysis. The aim of this study was to assess the role of cerebrospinal fluid (CSF) neopterin as a biomarker of disease severity in children with enterovirus-related brainstem encephalitis. METHODS: A descriptive, prospective cohort study was conducted from April 2016 to March 2017 in a tertiary hospital. Pediatric patients with a diagnosis of brainstem encephalitis with or without myelitis due to enterovirus infection were enrolled. The final study group comprised a convenience sample including all patients with sufficient CSF volume for neopterin determination. The major variables considered in estimating the severity were the diagnosis of encephalomyelitis, the presence of lesions and extensive lesions on brain and spinal magnetic resonance imaging (MRI), hospital stay length greater than seven days, and sequelae at day 30. RESULTS: Of 60 patients, CSF neopterin could be measured in 36. Median age was 26 months (interquartile range: 19 to 32). Thirty-three were diagnosed with brainstem encephalitis and three with encephalomyelitis. Enterovirus-A71 was the only identified genotype (25 of 25). CSF neopterin levels were elevated (>61 nmol/L) in 33 of 36 (92%), with a median of 347 nmol/L (interquartile range: 204 to 525). CSF neopterin was useful to distinguish patients with lesions on MRI (area under the receiver operating characteristic curve = 0.76; P = 0.02) and extensive lesions (area under the receiver operating characteristic curve = 0.76; P = 0.04). CONCLUSIONS: This study suggests an association between CSF neopterin levels and the presence of inflammatory lesions on MRI.

Acute epileptic seizures in myelin oligodendrocyte glycoprotein encephalomyelitis and neuromyelitis optica spectrum disorder: A comparative cohort study.

BACKGROUND: Little is known about the incidence and characteristics of acute epileptic seizures in myelin oligodendrocyte glycoprotein encephalomyelitis (MOG-EM) and neuromyelitis optica spectrum disorder (NMOSD). In this study, we compared the incidence and characteristics of acute epileptic seizures in MOG-EM and NMOSD patients. METHODS: MOG-EM (n = 61) and NMOSD (n = 565) cases obtained from the MSNMOBase (2011-2018) were retrospectively reviewed. RESULTS: Acute epileptic seizures were observed in 13 (21.3%) patients with MOG-EM and two (0.4%) patients with NMOSD (P < 0.001). In both MOG-EM and NMOSD patients, more than half of seizures were single and of focal onset; slow wave and cortical/subcortical lesions were the most common abnormalities. In MOG-EM patients, no difference was found in the proportion of single seizure with and without anti-epileptic drugs (AEDs; 64.3% vs. 45.5%, P = 0.435). Long-term AED use did not significantly reduce the occurrence of acute epileptic seizures, which was 66.7% before and after treatment. In patients with MOG-EM and NMOSD, mycophenolate mofetil significantly reduced acute epileptic seizure occurrence (P = 0.024). CONCLUSION: Acute epileptic seizures were more common in MOG-EM patients than in NMOSD patients. The long-term use of AEDs might be unnecessary given the use of immunotherapy in cases of MOG-EM.

Long-term outcome in neuroZika: When biological diagnosis matters.

OBJECTIVE: To characterize the full spectrum, relative frequency, and prognosis of the neurologic manifestations in Zika virus (ZIKV) postnatal infection. METHODS: We conducted an observational study in consecutive ZIKV-infected patients presenting with neurologic manifestations during the French West Indies 2016 outbreak. RESULTS: Eighty-seven patients, including 6 children, were enrolled. Ninety-five percent of all cases required hospitalization. Guillain-Barré syndrome was the most frequent manifestation (46.0%) followed by encephalitis or encephalomyelitis (20.7%), isolated single or multiple cranial nerve palsies (9.2%), other peripheral manifestations (6.9%), and stroke (1.1%). Fourteen patients (16.1%), including one child, developed a mixed disorder involving both the central and peripheral nervous system. Mechanical ventilation was required in 21 cases, all of whom had ZIKV RNA in at least one biological fluid. Two adult patients died due to neuroZika. Clinical follow-up (median 14 months; interquartile range, 13-17 months) was available for 76 patients. Residual disability (modified Rankin Scale score ≥2) was identified in 19 (25.0%) patients; in 6 cases (7.9%), disability was severe (modified Rankin Scale score ≥4). Among patients with ZIKV RNA detected in one biological fluid, the risk of residual disability or death was higher (odds ratio 9.19; confidence interval 1.12-75.22; p = 0.039). CONCLUSIONS: NeuroZika spectrum represents a heterogeneous group of clinical neurologic manifestations. During an outbreak, clinicians should consider neuroZika in patients presenting with cranial nerve palsies and a mixed neurologic disorder. Long-term sequelae are frequent in NeuroZika. ZIKV reverse-transcription PCR status at admission can inform prognosis and should therefore be taken into consideration in the management of hospitalized patients.

The distribution of inflammation and virus in human enterovirus 71 encephalomyelitis suggests possible viral spread by neural pathways.

Previous neuropathologic studies of Enterovirus 71 encephalomyelitis have not investigated the anatomic distribution of inflammation and viral localization in the central nervous system (CNS) in detail. We analyzed CNS and non-CNS tissues from 7 autopsy cases from Malaysia and found CNS inflammation patterns to be distinct and stereotyped. Inflammation was most marked in spinal cord gray matter, brainstem, hypothalamus, and subthalamic and dentate nuclei; it was focal in the cerebrum, mainly in the motor cortex, and was rare in dorsal root ganglia. Inflammation was absent in the cerebellar cortex, thalamus, basal ganglia, peripheral nerves, and autonomic ganglia. The parenchymal inflammatory response consisted of perivascular cuffs, variable edema, neuronophagia, and microglial nodules. Inflammatory cells were predominantly CD68-positive macrophage/microglia, but there were a few CD8-positive lymphocytes. There were no viral inclusions; viral antigens and RNA were localized only in the somata and processes of small numbers of neurons and in phagocytic cells. There was no evidence of virus in other CNS cells, peripheral nerves, dorsal root autonomic ganglia, or non-CNS organs. The results indicate that Enterovirus 71 is neuronotropic, and that, although hematogenous spread cannot be excluded, viral spread into the CNS could be via neural pathways, likely the motor but not peripheral sensory or autonomic pathways. Viral spread within the CNS seems to involve motor and possibly other pathways.

Limited remyelination in Theiler's murine encephalomyelitis due to insufficient oligodendroglial differentiation of nerve/glial antigen 2 (NG2)-positive putative oligodendroglial progenitor cells.

AIMS: Limited remyelination is a key feature of demyelinating Theiler's murine encephalomyelitis (TME). It is hypothesized that a dysregulation of differentiation of oligodendroglial progenitor cells (OPCs) represents the main cause of insufficient regeneration in this model of multiple sclerosis. METHODS: TME virus (TMEV)-infected SJL/J mice were evaluated by footprint analysis, light and electron microscopy, immunohistology, confocal immunofluorescence and RT-qPCR at multiple time points ranging from 1 h to 196 days post infection (dpi). RESULTS: Footprint analysis revealed a significantly decreased stride length at 147 and 196 dpi. Demyelination progressively increased from 14 towards 196 dpi. A mild amount of remyelination was detected at 147 and 196 dpi. Early onset axonal injury was detected from 14 dpi on. TMEV RNA was detectable throughout the observation period and markedly increased between 7 and 28 dpi. Intralesional nerve/glial antigen 2 (NG2)-positive OPCs were temporarily increased between 28 and 98 dpi. Similarly, a transient upregulation of NG2 and platelet-derived growth factor alpha-receptor mRNA was noticed. In contrast, intralesional 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase)-positive oligodendrocytes were decreased between 56 and 196 dpi. Although CNPase mRNA remained unchanged, myelin basic protein mRNA and especially its exon 2 containing splice variants were decreased. Glial fibrillary acidic protein (GFAP)-positive astrocytes and GFAP mRNA were increased in the late phase of TME. A mildly increased colocalization of both NG2/CNPase and NG2/GFAP was revealed at 196 dpi. CONCLUSIONS: Summarized, the present results indicated a dysregulation of OPC maturation as the main cause for the delayed and limited remyelination in TME. A shift of OPC differentiation from oligodendroglial towards astrocytic differentiation is postulated.