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.

Rate of Leptomeningeal Enhancement in Pediatric Myelin Oligodendrocyte Glycoprotein Antibody-Associated Encephalomyelitis.

INTRODUCTION: Myelin oligodendrocyte glycoprotein antibodies (MOG-abs) are associated with demyelinating diseases. Leptomeningeal enhancement occurs in 6% of adult MOG-abs patients but rates in pediatric MOG-abs patients are unknown. METHODS: Retrospective review of pediatric MOG-abs patients was performed. RESULTS: Twenty-one patients (7 boys, 14 girls) were included with an average age of 8.6 years (range 2-15 years). Seven of 21 (33%) pediatric MOG-abs patients had leptomeningeal enhancement. Two patients' relapses were manifested by leptomeningeal enhancement alone and another patient presented with seizures, encephalopathy, and aseptic meningitis without demyelinating lesions. Cerebrospinal fluid pleocytosis was seen in both leptomeningeal (4/7 patients) and nonleptomeningeal enhancement (10/14 patients). Interestingly, 3 patients with leptomeningeal enhancement had normal cerebrospinal fluid white blood cell count. Cortical edema was more likely in patients with leptomeningeal enhancement (P = .0263). CONCLUSION: We expand the clinical spectrum of anti-MOG antibody-associated disorder. Patients with recurrent leptomeningeal enhancement without demyelinating lesions should be tested for MOG antibodies.

Evaluation of diagnostic criteria and red flags of myelin oligodendrocyte glycoprotein encephalomyelitis in a clinical routine cohort.

AIMS: Myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) have been proposed to define "MOG encephalomyelitis" (MOG-EM), with published diagnostic and "red flag" criteria. We aimed to evaluate these criteria in a routine clinical setting. METHODS: We retrospectively analyzed patients with borderline/positive MOG-IgG and applied the diagnostic and red flag criteria to determine likelihood of MOG-EM diagnosis. Para-/clinical parameters were described and analyzed with chi-square test. RESULTS: In total, 37 patients fulfilled MOG-EM diagnostic criteria (female-to-male ratio: 1.6:1, median onset age: 28.0 years [IQR 18.5-40.5], n = 8 with pediatric onset). In 24/37, red flags were present, predominantly MOG-IgG at assay cutoff and/or MRI lesions suggestive of multiple sclerosis (MS). As proposed in the consensus criteria, these patients should rather be described as "possible" MOG-EM. Of these, we classified 13 patients as "unlikely" MOG-EM in the presence of the red flag "borderline MOG-IgG" with negative MOG-IgG retest or coincidence of ≥1 additional red flag. This group mainly consisted of patients diagnosed with MS (n = 11). Frequency of cerebrospinal fluid (CSF-)-specific oligoclonal bands (OCB) is significantly lower in definite vs possible and unlikely MOG-EM (P = .0005). CONCLUSION: Evaluation of diagnostic and red flag criteria, MOG-IgG retesting (incl. change of assay), and CSF-specific OCB are relevant in clinical routine cohorts to differentiate MOG-EM from MS.

Cerebrospinal fluid findings in patients with myelin oligodendrocyte glycoprotein (MOG) antibodies. Part 1: Results from 163 lumbar punctures in 100 adult patients.

BACKGROUND: New-generation cell-based assays have demonstrated a robust association of serum autoantibodies to full-length human myelin oligodendrocyte glycoprotein (MOG-IgG) with (mostly recurrent) optic neuritis, myelitis, and brainstem encephalitis, as well as with neuromyelitis optica (NMO)-like or acute-disseminated encephalomyelitis (ADEM)-like presentations. However, only limited data are yet available on cerebrospinal fluid (CSF) findings in MOG-IgG-associated encephalomyelitis (MOG-EM; also termed MOG antibody-associated disease, MOGAD). OBJECTIVE: To describe systematically the CSF profile in MOG-EM. MATERIAL AND METHODS: Cytological and biochemical findings (including white cell counts and differentiation; frequency and patterns of oligoclonal bands; IgG/IgM/IgA and albumin concentrations and CSF/serum ratios; intrathecal IgG/IgA/IgM fractions; locally produced IgG/IgM/IgA concentrations; immunoglobulin class patterns; IgG/IgA/IgM reibergrams; Link index; measles/rubella/zoster (MRZ) reaction; other anti-viral and anti-bacterial antibody indices; CSF total protein; CSF L-lactate) from 163 lumbar punctures in 100 adult patients of mainly Caucasian descent with MOG-EM were analyzed retrospectively. RESULTS: Most strikingly, CSF-restricted oligoclonal IgG bands, a hallmark of multiple sclerosis (MS), were absent in almost 90% of samples (N = 151), and the MRZ reaction, the most specific laboratory marker of MS known so far, in 100% (N = 62). If present, intrathecal IgG (and, more rarely, IgM) synthesis was low, often transient and mostly restricted to acute attacks. CSF WCC was elevated in > 50% of samples (median 31 cells/µl; mostly lymphocytes and monocytes; > 100/µl in 12%). Neutrophils were present in > 40% of samples; activated lymphocytes were found less frequently and eosinophils and/or plasma cells only very rarely (< 4%). Blood-CSF barrier dysfunction (as indicated by an elevated albumin CSF/serum ratio) was present in 48% of all samples and at least once in 55% of all patients (N = 88) tested. The frequency and degree of CSF alterations were significantly higher in patients with acute myelitis than in patients with acute ON and varied strongly depending on attack severity. CSF L-lactate levels correlated significantly with the spinal cord lesion load in patients with acute myelitis (p < 0.0001). Like pleocytosis, blood-CSF barrier dysfunction was present also during remission in a substantial number of patients. CONCLUSION: MOG-IgG-positive EM is characterized by CSF features that are distinct from those in MS. Our findings are important for the differential diagnosis of MS and MOG-EM and add to the understanding of the immunopathogenesis of this newly described autoimmune disease.

Cerebrospinal fluid findings in patients with myelin oligodendrocyte glycoprotein (MOG) antibodies. Part 2: Results from 108 lumbar punctures in 80 pediatric patients.

BACKGROUND: New-generation, cell-based assays have demonstrated a robust association of serum autoantibodies to full-length human myelin oligodendrocyte glycoprotein (MOG-IgG) with (mostly recurrent) optic neuritis, myelitis, and brainstem encephalitis, as well as with neuromyelitis optica (NMO)-like or acute-disseminated encephalomyelitis (ADEM)-like presentations. However, only limited data are yet available on cerebrospinal fluid (CSF) findings in MOG-IgG-associated encephalomyelitis (MOG-EM; also termed MOG antibody-associated disease, MOGAD). OBJECTIVE: To describe systematically the CSF profile in children with MOG-EM. MATERIAL AND METHODS: Cytological and biochemical findings (including white cell counts [WCC] and differentiation; frequency and patterns of oligoclonal bands; IgG/IgM/IgA and albumin concentrations and CSF/serum ratios; intrathecal IgG/IgM/IgA fractions; locally produced IgG/IgM/IgA concentrations; immunoglobulin class patterns; IgG/IgA/IgM reibergrams; Link index; measles/rubella/zoster [MRZ] reaction; other anti-viral and anti-bacterial antibody indices; CSF total protein; CSF L-lactate) from 108 lumbar punctures in 80 pediatric patients of mainly Caucasian descent with MOG-EM were analyzed retrospectively. RESULTS: Most strikingly, CSF-restricted oligoclonal IgG bands, a hallmark of multiple sclerosis (MS), were absent in 89% of samples (N = 96), and the MRZ reaction, the most specific laboratory marker of MS known so far, in 100% (N = 29). If present at all, intrathecal IgG synthesis was low, often transient and mostly restricted to acute attacks. Intrathecal IgM synthesis was present in 21% and exclusively detectable during acute attacks. CSF WCC were elevated in 54% of samples (median 40 cells/µl; range 6-256; mostly lymphocytes and monocytes; > 100/µl in 11%). Neutrophils were present in 71% of samples; eosinophils, activated lymphocytes, and plasma cells were seen only rarely (all < 7%). Blood-CSF barrier dysfunction (as indicated by an elevated albumin CSF/serum ratio) was present in 46% of all samples (N = 79) and at least once in 48% of all patients (N = 67) tested. CSF alterations were significantly more frequent and/or more pronounced in patients with acute spinal cord or brain disease than in patients with acute ON and varied strongly depending on attack severity. CSF L-lactate levels correlated significantly with the spinal cord lesions load (measured in vertebral segments) in patients with acute myelitis (p = 0.0099). An analysis of pooled data from the pediatric and the adult cohort showed a significant relationship of QAlb (p < 0.0005), CST TP (p < 0.0001), and CSF L-lactate (p < 0.0003) during acute attacks with age. CONCLUSION: MOG-IgG-associated EM in children is characterized by CSF features that are distinct from those in MS. With regard to most parameters, no marked differences between the pediatric cohort and the adult cohort analyzed in Part 1 were noted. Our findings are important for the differential diagnosis of pediatric MS and MOG-EM and add to the understanding of the immunopathogenesis of this newly described autoimmune disease.

MOG encephalomyelitis: distinct clinical, MRI and CSF features in patients with longitudinal extensive transverse myelitis as first clinical presentation.

BACKGROUND: Based on clinical, immunological and histopathological evidence, MOG-IgG-associated encephalomyelitis (MOG-EM) has emerged as a distinct disease entity different from multiple sclerosis (MS) and aquaporin-4-antibody-positive neuromyelitis optica spectrum disorder (NMOSD). MOG-EM is associated with a broader clinical phenotype including optic neuritis, myelitis, brainstem lesions and acute disseminated encephalomyelitis with a substantial clinical and radiological overlap to other demyelinating CNS disorders. OBJECTIVE: To evaluate common clinical, MRI and CSF findings, as well as therapy responses in patients with longitudinal extensive transverse myelitis (LETM) as initial clinical presentation of MOG-EM. METHODS: After excluding patients with a known diagnosis of MS, we identified 153 patients with myelitis of which 7 fulfilled the inclusion criteria and were investigated for MRI, CSF and clinical parameters. RESULTS: Patients with LETM as first clinical presentation of MOG-EM display similar characteristics, namely a lack of gadolinium-enhancement in spinal cord MRI, marked pleocytosis, negative oligoclonal bands, a previous history of infections/vaccinations and response to antibody-depleting treatments for acute attacks and long-term treatment. CONCLUSIONS: We identify common pathological findings in patients with LETM as first clinical presentation of MOG-EM which distinguishes it from other forms of LETM and should lead to testing for MOG-IgG in these cases.

Analysis of neurofilament concentration in healthy adult horses and utility in the diagnosis of equine protozoal myeloencephalitis and equine motor neuron disease.

Neurofilaments (NFs) are structural proteins of neurons that are released in significant quantities in the cerebrospinal fluid and blood as a result of neuronal degeneration or axonal damage. Therefore, NFs have potential as biomarkers for neurologic disorders. Neural degeneration increases with age and has the potential to confound the utility of NFs as biomarkers in the diagnosis of neurologic disorders. We investigated this relationship in horses with and without neurological diagnosis. While controlling for horse type (draft, pleasure, and racing), we evaluated the relationship between serum heavy-chain phosphorylated neurofilaments (pNF-H) and age, sex, and serum vitamin E concentrations. Serum pNF-H concentrations increased by 0.002 ng/ml for each year increase in age. There were significant differences in the serum pNF-H concentration among the type of activity performed by the horse. The highest serum pNF-H concentration was found in horses performing heavy work activity (racehorse) and with lower serum pNF-H concentration found among light (pleasure riding) and moderate (draft) activity. There was no significant association between the pNF-H concentration and sex or vitamin E concentration. Serum pNF-H concentration was elevated among horses afflicted with EMND and EPM when compared with control horses without evidence of neurologic disorders. Accordingly, serum pNF-H concentration can serve as a useful biomarker to complement the existing diagnostic work-up of horses suspected of having EPM or EMND.

[MOG encephalomyelitis: international recommendations on diagnosis and antibody testing]. / MOG-Enzephalomyelitis: Internationale Empfehlungen zu Diagnose und Antikörpertestung.

Over the past few years, new-generation cell-based assays have demonstrated a robust association of autoantibodies to full-length human myelin oligodendrocyte glycoprotein (MOG-IgG) with (mostly recurrent) optic neuritis, myelitis and brainstem encephalitis, as well as with acute disseminated encephalomyelitis (ADEM)-like presentations. Most experts now consider MOG-IgG-associated encephalomyelitis (MOG-EM) a disease entity in its own right, immunopathogenetically distinct from both classic multiple sclerosis (MS) and aquaporin-4 (AQP4)-IgG-positive neuromyelitis optica spectrum disorders (NMOSD). Owing to a substantial overlap in clinicoradiological presentation, MOG-EM was often unwittingly misdiagnosed as MS in the past. Accordingly, increasing numbers of patients with suspected or established MS are currently being tested for MOG-IgG. However, screening of large unselected cohorts for rare biomarkers can significantly reduce the positive predictive value of a test. To lessen the hazard of overdiagnosing MOG-EM, which may lead to inappropriate treatment, more selective criteria for MOG-IgG testing are urgently needed. In this paper, we propose indications for MOG-IgG testing based on expert consensus. In addition, we give a list of conditions atypical for MOG-EM ("red flags") that should prompt physicians to challenge a positive MOG-IgG test result. Finally, we provide recommendations regarding assay methodology, specimen sampling and data interpretation, and propose for the first time diagnostic criteria for MOG-EM.

Autoimmune GFAP astrocytopathy: Prospective evaluation of 90 patients in 1 year.

In this prospective evaluation of serum and CSF samples, all but two CSF GFAPα-IgG positive patients had autoimmune meningoencephalomyelitis while serum GFAPα-IgG positivity alone was less specific. Phenotypes were diverse among patients that were serum positive only. Adult and pediatric clinical presentations were similar. Most patients were immunotherapy responsive. Co-existing NMDA-R-IgG and cancer were associated with lack of response to first-line immunotherapy. Among patients with follow-up information, 18% had relapses. This study demonstrates CSF GFAPα-IgG is a specific autoimmune meningoencephalomyelitis biomarker, with favorable corticosteroid response. Lack of response should prompt evaluation for co-existing NMDA-R-IgG or malignancy.

MOG encephalomyelitis: international recommendations on diagnosis and antibody testing.

Over the past few years, new-generation cell-based assays have demonstrated a robust association of autoantibodies to full-length human myelin oligodendrocyte glycoprotein (MOG-IgG) with (mostly recurrent) optic neuritis, myelitis and brainstem encephalitis, as well as with acute disseminated encephalomyelitis (ADEM)-like presentations. Most experts now consider MOG-IgG-associated encephalomyelitis (MOG-EM) a disease entity in its own right, immunopathogenetically distinct from both classic multiple sclerosis (MS) and aquaporin-4 (AQP4)-IgG-positive neuromyelitis optica spectrum disorders (NMOSD). Owing to a substantial overlap in clinicoradiological presentation, MOG-EM was often unwittingly misdiagnosed as MS in the past. Accordingly, increasing numbers of patients with suspected or established MS are currently being tested for MOG-IgG. However, screening of large unselected cohorts for rare biomarkers can significantly reduce the positive predictive value of a test. To lessen the hazard of overdiagnosing MOG-EM, which may lead to inappropriate treatment, more selective criteria for MOG-IgG testing are urgently needed. In this paper, we propose indications for MOG-IgG testing based on expert consensus. In addition, we give a list of conditions atypical for MOG-EM ("red flags") that should prompt physicians to challenge a positive MOG-IgG test result. Finally, we provide recommendations regarding assay methodology, specimen sampling and data interpretation.

MOG antibody-related disorders: common features and uncommon presentations.

Myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) have been reported in acute demyelinating encephalomyelitis (ADEM), optic neuritis (ON), and neuromyelitis optica spectrum disorders (NMOSD) in adults and pediatrics. We aimed to delineate the common features of MOG-Ab-related disorders in children and adults, and report uncommon presentations. Twenty-seven consecutive pediatric and adult patients testing positive for MOG-Ab, with a minimum follow-up of 6 months, were included. Comprehensive epidemiological, clinical, radiological, and laboratory data were retrospectively analyzed. Additionally, we compared radiological features between ADEM MOG-Ab-positive patients, and a group of ADEM MOG-Ab-negative ones, recruited during the same period. Among the whole cohort, 13 (48.1%) were pediatric, and 14 (51.9%) were female. MOG-Ab-related disorders comprised eight ADEM, eight ON, five isolated myelitis, four with NMOSD and two patients with multiple sclerosis, at last follow-up. After a median follow-up of 17.8 months, 11 (40.7%) patients presented a relapse. The most frequent clinical phenotype at onset was encephalopathy in pediatrics (53.9%) and myelitis in adults (50%) (p = 0.013). There were no other differences between both groups. When comparing ADEM MOG-Ab positive and negative patients, bilateral thalamic lesions were more often found in the positive group (p = 0.010). Unusual presentations were identified in three patients: patchy spinal cord gadolinium-enhancing lesions, an associated teratoma, and one presented with status epilepticus. MOG-Ab-related disorders shared common clinical and prognostic features, but encompass a spectrum wider than recently reported.

Phosphorylated neurofilament H (pNF-H) as a potential diagnostic marker for neurological disorders in horses.

The current study aimed at the investigating the potential use of phosphorylated neurofilament H (pNF-H) as a diagnostic biomarker for neurologic disorders in the horse. Paired serum and cerebrospinal fluid (CSF) samples (n=88) and serum only (n=30) were obtained from horses diagnosed with neurologic disorders and clinically healthy horses as control. The neurologic horses consisted of equine protozoal myeloencephalitis (EPM) (38 cases) and cervical vertebral malformation (CVM) (23 cases). Levels of pNF-H were determined using an ELISA. The correlation between CSF and serum concentrations of pNF-H was evaluated using Spearman's Rank test and the significance of the difference among the groups was assessed using a nonparametric test. Horses had higher pNF-H levels in the CSF than serum. Horses afflicted with EPM had significantly higher serum pNF-H levels in comparison to controls or CVM cases. The correlation between CSF and serum pNF-H levels was poor in both the whole study population and among subgroups of horses included in the study. There was significant association between the likelihood of EPM and the concentrations of pNF-H in either the serum or CSF. These data suggest that pNF-H could be detected in serum and CSF samples from neurologic and control horses. This study demonstrated that pNF-H levels in serum and CSF have the potential to provide objective information to help in the early diagnosis of horses afflicted with neurologic disorders.

Diagnostic algorithm for relapsing acquired demyelinating syndromes in children.

OBJECTIVE: To establish whether children with relapsing acquired demyelinating syndromes (RDS) and myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) show distinctive clinical and radiologic features and to generate a diagnostic algorithm for the main RDS for clinical use. METHODS: A panel reviewed the clinical characteristics, MOG-Ab and aquaporin-4 (AQP4) Ab, intrathecal oligoclonal bands, and Epstein-Barr virus serology results of 110 children with RDS. A neuroradiologist blinded to the diagnosis scored the MRI scans. Clinical, radiologic, and serologic tests results were compared. RESULTS: The findings showed that 56.4% of children were diagnosed with multiple sclerosis (MS), 25.4% with neuromyelitis optica spectrum disorder (NMOSD), 12.7% with multiphasic disseminated encephalomyelitis (MDEM), and 5.5% with relapsing optic neuritis (RON). Blinded analysis defined baseline MRI as typical of MS in 93.5% of children with MS. Acute disseminated encephalomyelitis presentation was seen only in the non-MS group. Of NMOSD cases, 30.7% were AQP4-Ab positive. MOG-Ab were found in 83.3% of AQP4-Ab-negative NMOSD, 100% of MDEM, and 33.3% of RON. Children with MOG-Ab were younger, were less likely to present with area postrema syndrome, and had lower disability, longer time to relapse, and more cerebellar peduncle lesions than children with AQP4-Ab NMOSD. A diagnostic algorithm applicable to any episode of CNS demyelination leads to 4 main phenotypes: MS, AQP4-Ab NMOSD, MOG-Ab-associated disease, and antibody-negative RDS. CONCLUSIONS: Children with MS and AQP4-Ab NMOSD showed features typical of adult cases. Because MOG-Ab-positive children showed notable and distinctive clinical and MRI features, they were grouped into a unified phenotype (MOG-Ab-associated disease), included in a new diagnostic algorithm.

Plasma and serum concentrations of cytarabine administered via continuous intravenous infusion to dogs with meningoencephalomyelitis of unknown etiology.

The objective of this study was to evaluate the plasma and serum concentrations of cytarabine (CA) administered via constant rate infusion (CRI) in dogs with meningoencephalomyelitis of unknown etiology (MUE). Nineteen client-owned dogs received a CRI of CA at a dose of 25 mg/m2 /h for 8 h as treatment for MUE. Dogs were divided into four groups, those receiving CA alone and those receiving CA in conjunction with other drugs. Blood samples were collected at 0, 1, 8, and 12 h after initiating the CRI. Plasma (n = 13) and serum (n = 11) cytarabine concentrations were measured by high-pressure liquid chromatography. The mean peak concentration (CMAX ) and area under the curve (AUC) after CRI administration were 1.70 ± 0.66 µg/mL and 11.39 ± 3.37 h·µg/mL, respectively, for dogs receiving cytarabine alone, 2.36 ± 0.35 µg/mL and 16.91 + 3.60 h·µg/mL for dogs administered cytarabine and concurrently on other drugs. Mean concentrations for all dogs were above 1.0 µg/mL at both the 1- and 8-h time points. The steady-state achieved with cytarabine CRI produces a consistent and prolonged exposure in plasma and serum, which is likely to produce equilibrium between blood and the central nervous system in dogs with a clinical diagnosis of MUE. Other medications commonly used to treat MUE do not appear to alter CA concentrations in serum and plasma.

Expression of microRNAs miR-21 and miR-181c in cerebrospinal fluid and serum in canine meningoencephalomyelitis of unknown origin.

The potential of microRNAs (miRNAs) as biomarkers for canine meningoencephalomyelitis of unknown origin (MUO) was investigated by using quantitative real-time (qRT)-PCR to determine the expression of microRNA-21 (miR-21) and microRNA-181c (miR-181c) in the cerebrospinal fluid (CSF) of dogs. Dogs with MUO (n = 10) had higher levels of expression of miR-21 and miR-181c in the CSF than dogs with non-inflammatory neurological diseases (n = 8). There was a positive correlation between CSF cellularity and expression of miRNAs in the CSF, particularly for miR-21 in the MUO group.

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.