Comparison of myelin oligodendrocyte glycoprotein (MOG)-antibody disease and AQP4-IgG-positive neuromyelitis optica spectrum disorder (NMOSD) when they co-exist with anti-NMDA (N-methyl-D-aspartate) receptor encephalitis

Clinical and imaging features and treatment response of anti-NMDAR encephalitis combined with MOGAD

BACKGROUND

To investigate the clinical, imaging features, immunotherapy of anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) combined with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).

METHODS

A total of 124 patients with NMDARE and 86 patients with MOGAD were screened from an ongoing prospective cohort study (Clinical and Imaging Patterns of Neuroinflammation Diseases in China, CLUE). Ten NMDARE combined with MOGAD patients, were finally enrolled in this study. Clinical and imaging data and follow-up results characteristics were collected and analyzed.

RESULTS

In these 10 patients with NMDARE combined with MOGAD, 7 patients (70 %) showed recurrent courses. In all 26 episodes, 14 episodes (53.8 %) showed encephalitis-related symptoms, 6 episodes (23.1 %) showed demyelination-related symptoms, 6 episodes (23.1 %) showed both. The median CSF leukocytes were 13/μL (range 1-413) and the median protein was 0.43 g/L (range 0.22-0.70). MRI lesions were found involving the optic nerve (2/10), spinal cord (3/10), deep gray matter (3/10), cortex (6/10), subcortex (7/10), brainstem (5/10) and cerebellum (4/10). Leptomeningeal enhancement was found in 3 patients. All patients received high-dose intravenous methylprednisolone and immunoglobulin therapy during attacks. Seven patients received rituximab (RTX). The median annualized recurrence rate (ARR) reduced significantly following RTX treatments (z = -2.201, p = 0.028), and achieved good outcomes at the last follow-up visit (modified Rankin scale score ≤ 2).

CONCLUSION

NMDARE combined with MOGAD represents a unique characteristic of autoantibody-mediated encephalitis. Coexistence of NMDAR and MOG antibody may indicate high recurrence risk. RTX may be a relatively efficient therapeutic option.

A complex and severe encephalitis associated with four co-existing neuronal cell-surface autoantibodies

Many forms of autoimmune encephalitis are mediated by neuronal cell-surface directed autoantibodies. The co-occurrence of four neuronal cell-surface antibodies in a single patient is exceptionally rare. We report a patient who had a severe encephalitis associated with antibodies to NMDA, Glycine, GABAA and GABAB receptors. Case: A 28-year-old man on tacrolimus presented with a first seizure. Thereafter, he developed confusion, cerebellar signs, opsoclonus, neuromyotonia and medication-refractory seizures. CSF sampling revealed 826 white cells and NMDA, glycine and GABAB receptor antibodies: all were also detected in serum along with additional GABAA receptor antibodies. Neural antibodies were detected using fixed (NMDA, GABAA, GABAB receptor) or live (glycine receptor) cell-based assays at Oxford Neuroimmunology Laboratory, Oxford, UK. MRI brain demonstrated cerebellar leptomeningeal enhancement and a hyperintense lesion in the cerebellar vermis. EEG revealed extreme delta brush and needle EMG confirmed neuromyotonia. No underlying malignancy was detected. Methylprednisolone, IVIG, Rituximab, therapeutic plasma exchange, cyclophosphamide and bortezomib were administered sequentially, with minimal clinical improvement. Death secondary to respiratory sepsis occurred on the 714th hospital day. Postmortem revealed pan-cerebellar atrophy with Purkinje cell loss; dentate nucleus ganglionopathy, and thoracolumbar cord myelopathy. In summary, the detection of multiple neuronal cell-surface antibodies in autoimmune encephalitis is unusual and may result in a complex overlap syndrome with a poor response to immunotherapy.

Concurrent myasthenia gravis and neuromyelitis optica spectrum disorder: a rare intersection of autoimmune pathologies

This case report describes a woman in her 50s with a rare coexistence of neuromyelitis optica spectrum disorder (NMOSD) and myasthenia gravis (MG), highlighting the diagnostic challenges and therapeutic considerations. Initially diagnosed with acetylcholine receptor antibody-positive MG, she later developed progressive visual impairment, leading to a diagnosis of NMOSD. Rituximab treatment was effective in managing both conditions, demonstrating the benefits of targeted therapies in reducing complications related to polypharmacy. This case underscores the importance of clinical vigilance and a multidisciplinary approach in managing overlapping autoimmune disorders, offering insights into their inter-relationships and therapeutic strategies.

Clinical Analysis of MOG Antibody-Associated Disease Overlapped With Anti-NMDA Receptor Encephalitis: A Long-Term Retrospective Study

To summarise the clinical characteristics, radiological features, treatments and prognosis of patients with myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) overlapped with NMDA receptor (NMDAR) encephalitis. We retrospectively analysed patients who exhibited dual positivity for MOG antibodies and NMDAR antibodies in serum/CSF from Jan 2018 to Jun 2023. Ten patients with MOGAD and NMDAR encephalitis were enrolled. The median age of initial attacks was 23 (range: 10-43) years old. Common symptoms were cortical encephalopathies (8/10), focal neurological deficits (4/10), as well as other presentations including headache, fever, optic neuritis and transverse myelitis. CSF pleocytosis was general (9/10, median 63.9 cells/μl). Lesions on brain MRI included brainstem (37.5%), cerebral cortex (33.3%), basal ganglia (25.0%) and hippocampus (20.8%). The average follow-up duration was 25.4 months. 10/10 patients developed more than one relapse attacks, with MOG positivity before (10%), simultaneous (40%) or after anti-NMDAR encephalitis (50%). Most patients (7/10) had good response to first-line therapy but experienced next relapse with an average interval of 6.7 (range: 2-14) months. We conducted initial analysis of lymphocyte subsets in these patients, which revealed that CD3+ and CD4 + T cells increased after immunosuppressants medication (p < 0.01 and p < 0.05, respectively). We concluded that MOGAD overlapping with NMDAR encephalitis presents a distinct clinical phenotype which differs from either MOGAD or NMDAR encephalitis. Brainstem in combination with cortical lesions might be warning signs for this overlapping syndrome. Due to the high recurrent rates, we recommend early diagnosis and timely treatment with efficient immunosuppressants at onset.

Clinical features of adult patients with positive NMDAR-IgG coexisting with MOG-IgG

INTRODUCTION

This study was designed to analyze clinical and radiographic features of adult patients coexisting with NMDAR-IgG and MOG-IgG.

METHODS

Eleven adult patients coexisting with NMDAR-IgG and MOG-IgG were collected from Xiangya Hospital, Central South University, between June 2017 and December 2021. Fifty-five patients with anti-NMDAR encephalitis and 49 with MOG-AD were served as controls.

RESULTS

Onset age was 27 (IQR 20-34) years old. Seizures and psychotic symptoms were prominent symptoms. Ten of eleven patients presented abnormal T2/FLAIR hyperintensity, mainly involving the cortex, brainstem, and optic nerve. Compared with the NMDAR IgG ( +)/MOG IgG ( -) group, the NMDAR IgG ( +)/MOG IgG ( +) group showed more ataxia symptoms (27.3% vs. 3.6%, P = 0.037), while more T2/FLAIR hyperintensity lesions were found in the brainstem (54.5% vs. 7.3%, P < 0.001) and optic nerve (27.3% vs. 1.8%, P = 0.011) with more abnormal MRI patterns (90.9% vs. 41.8%, P = 0.003). In comparison with the NMDAR IgG ( -)/MOG IgG ( +) group, the NMDAR IgG ( +)/MOG IgG ( +) group had more seizures (72.7% vs. 24.5%, P = 0.007) and mental symptoms (45.5% vs. 0, P < 0.001). The NMDAR IgG ( +)/MOG IgG ( +) group tended to be treated with corticosteroids alone (63.6% vs. 20.0%, P = 0.009), more prone to recur (36.5% vs. 7.3%, P = 0.028) and lower mRS score (P = 0.036) at the last follow-up than pure anti-NMDAR encephalitis.

CONCLUSION

The symptoms of the NMDAR IgG ( +)/MOG IgG ( +) group were more similar to anti-NMDAR encephalitis, while MRI patterns overlapped more with MOG-AD. Detecting both NMDAR-IgG and MOG-IgG maybe warranted in patients with atypical encephalitis symptoms and demyelinating lesions in infratentorial regions.

Less common phenotypes of myelin oligodendrocyte glycoprotein antibody-related diseases in children deserve more attention

BACKGROUND

To facilitate the identification of less common clinical phenotypes of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) in children.

METHODS

We retrospectively reviewed medical records of 236 patients with MOGAD. The following phenotypes were considered to be typical for MOGAD: ADEM, ON, TM, and NMOSD. Less common onset clinical phenotypes were screened out; their clinical and magnetic resonance imaging (MRI), diagnosis, treatment, and prognosis were summarized and analyzed.

RESULTS

16 cases (6.8%) presented as cortical encephalitis, with convulsions, headache, and fever as the main symptoms. 15 cases were misdiagnosed in the early period. 13 cases (5.5%) showed the overlapping syndrome of MOGAD and anti-N-methyl-D aspartate receptor encephalitis (MNOS), with seizures (92.3%) being the most common clinical symptom. 11 cases (84.6%) showed relapses. The cerebral leukodystrophy-like phenotype was present in seven cases (3.0%), with a recurrence rate of 50%. Isolated seizures without any findings on MRI phenotype was present in three cases (1.3%), with the only clinical symptom being seizures of focal origin. Three cases (1.3%) of aseptic meningitis phenotype presented with prolonged fever.

CONCLUSION

40/236 (16.9%) of children with MOGAD had less common phenotypes. Less common clinical phenotypes of pediatric MOGAD are susceptible to misdiagnosis and deserve more attention.

IMPACT

This is the first comprehensive analysis and summary of all less commonl clinical phenotypes of MOGAD in children, while previous studies have only focused on a specific phenotype or case reports. We analyzed the characteristics of MOGAD in children and further revealed the reasons why these less common clinical phenotypes are prone to misdiagnosis and deserve more attention. Our research on treatment has shown that early detection of MOG antibodies and early treatment are of great significance for improving the prognosis of these patients.

Efficacy of steroid therapy in the acute stage of anti-NMDAR and anti-MOG antibody overlapping encephalitis: a case report and literature review

Background

Recently, cases of overlapping encephalitis caused by anti-N-methyl-D-aspartate receptor (anti-NMDAR) and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies have been reported, and their clinical characteristics are gradually becoming clear. Acute-phase treatment typically involves the use of steroids, and although some studies have suggested that steroids can be effective, the extent of their efficacy has not yet been fully explored.

Case presentation

We present the case of a 25-year-old man with anti-NMDAR and anti-MOG antibody overlapping encephalitis who showed considerable improvement after steroid treatment. To gain a deeper understanding of the efficacy of steroids in managing this condition, we conducted a literature review of cases of anti-NMDAR and anti-MOG antibody double-positive encephalitis that were treated with steroids during the acute phase. Thirteen cases were analyzed, including a new case diagnosed at our hospital. All patients showed improvement after receiving steroid treatment in the acute phase. Ten patients did not have any sequelae, and nine of them showed a rapid or major response during the acute phase. In contrast, three patients experienced sequelae (mild cognitive decline, visual impairment, and memory impairment, respectively), with their response to steroids in the acute phase being slow or limited. Relapses occurred in five patients, in one patient during steroid tapering, and in another two patients after cessation of steroids.

Conclusion

Steroid therapy can be effective in the acute stage of anti-NMDAR and anti-MOG antibody overlapping encephalitis. A positive prognosis may be expected in patients who experience substantial improvement with steroid therapy during the acute phase.

FLAMES overlaying anti-N-methyl-D-aspartate receptor encephalitis: a case report and literature review

BACKGROUND

In recent years, simultaneous or sequential occurrence of MOG antibody disease and anti-NMDAR encephalitis in the same patient has been reported with increasing frequency. Scholars refer to the overlapping occurrence of these two disorders as MOG antibody disease and anti-NMDAR encephalitis overlap syndrome (MNOS). Cortical T2-weighted fluid-attenuated inversion recovery (FLAIR) -hyperintense lesions in anti-MOG-associated encephalitis with seizures (FLAMES) is a rare clinical phenotype of MOGAD in which cortical FLAIR high-signal lesions are unilateral, with little spread to the cortex and meninges bilaterally. Although cases of FLAMES have been consistently reported. However, to our knowledge, such cases of FLAMES combined with NMDARE are rare.

CASE PRESENTATION

Here, we describe a case of FLAMES combined with anti-NMDARE. The patient was a young male, 29 years old, admitted to our hospital with isolated seizures, whose MRI showed unilateral thalamic and bilateral frontal and parietal leptomeningeal involvement. Since we were unaware of the possibility of bilateral meningo-cortical MOGAD manifestations, the case was initially diagnosed as viral encephalitis and was given antiviral therapy. The diagnosis was not clarified until anti-NMDAR-IgG and MOG-IgG positivity was detected in the cerebrospinal fluid and serum. The patient was then treated with high-dose corticosteroids and his symptoms responded well to the steroids. Therefore, this case expands the clinical spectrum of MNOS overlap syndrome. In addition, we describe the clinical features of MNOS by summarizing the existing literature and exploring the possible mechanisms of its immune response.

CONCLUSIONS

Our case serves as a reminder to clinicians that when patients present with atypical clinical manifestations such as seizures, consideration should be given to MNOS and conduct testing for various relevant autoantibodies (including MOG abs) and viruses in both serum and cerebrospinal fluid, as it is easy to misdiagnose the disease as other CNS diseases, such as viral meningoencephalitis. This syndrome exhibits a high responsiveness to steroids, highlighting the critical importance of recognizing the clinical and neuroimaging features of this overlap syndrome for prompt diagnosis and treatment. Furthermore, it enriches the disease spectrum of MNOS.

Immune-Mediated Myelopathies

OBJECTIVE

Immune-mediated myelopathies are conditions in which the immune system attacks the spinal cord. This article describes the distinguishing characteristics of immune-mediated myelopathies and treatment strategies for patients affected by these disorders.

LATEST DEVELOPMENTS

New biomarkers, such as aquaporin 4 and myelin oligodendrocyte glycoprotein antibodies, in the blood and spinal fluid have led to the identification of antigen-specific immune-mediated myelopathies and approved therapies to prevent disease progression.

ESSENTIAL POINTS

The first step in the diagnosis of an immune-mediated myelopathy is confirming that the immune system is the cause of the attack by excluding non-immune-mediated causes. The second step is to narrow the differential diagnosis based on objective biomarkers such as serology and MRI patterns. The third step is to treat the specific immune-mediated myelopathy by using evidence-based medicine.

Myelin oligodendrocyte glycoprotein antibody and N-methyl-d-aspartate receptor antibody overlapping syndrome: insights from the recent case reports

The overlapping of two or more types of neural autoantibodies in one patient has increasingly been documented in recent years. The coexistence of myelin oligodendrocyte glycoprotein (MOG) and N-methyl-d-aspartate receptor (NMDAR) antibodies is most common, which leads to a unique condition known as the MOG antibody and NMDAR antibody overlapping syndrome (MNOS). Here, we have reviewed the pathogenesis, clinical manifestations, paraclinical features, and treatment of MNOS. Forty-nine patients with MNOS were included in this study. They were young males with a median onset age of 23 years. No tumors were observed in the patients, and 24 of them reported prodromal symptoms. The most common clinical presentations were psychiatric symptoms (35/49) and seizures (25/49). Abnormalities on magnetic resonance imaging involved the brainstem (11/49), cerebellum (9/49), and parietal lobe (9/49). Most patients mostly responded to immunotherapy and had a good long-term prognosis. However, the overall recurrence rate of MNOS was higher than that of mono antibody-positive diseases. The existence of concurrent NMDAR antibodies should be suspected in patients with MOG antibody-associated disease having psychiatric symptoms, seizures, movement disorders, or autonomic dysfunction. Similarly, serum MOG antibody testing should be performed when patients with anti-NMDAR encephalitis present with atypical clinical manifestations, such as visual impairment and limb weakness, and neuroradiological findings, such as optic nerve, spinal cord, or infratentorial involvement or meningeal enhancement. Early detection of the syndrome and prompt treatment can be beneficial for these patients, and maintenance immunosuppressive therapy is recommended due to the high overall recurrence rate of the syndrome.

Clinical characteristics of Chinese pediatric patients positive for anti-NMDAR and MOG antibodies: a case series

Introduction

The cases of MOG-AD (MOG antibody-associated disorder) and anti-NMDAR encephalitis overlapping syndrome (MNOS) are rare, especially among pediatric patients, and their clinical understanding is limited. This study aimed to investigate the clinical manifestations, imaging findings, treatments, and prognosis of Chinese pediatric patients who tested positive for anti-NMDAR and MOG antibodies.

Methods

This retrospective study enrolled 10 MNOS pediatric patients, 50 MOG-AD (anti-NMDAR antibody-negative), and 81 anti-NMDAR encephalitis (MOG antibody-negative) pediatric patients who were admitted from July 2016 to June 2022 and used their clinical data for comparison.

Results

The MNOS patients had a significantly lower incidence of psycho-behavioral abnormalities and involuntary movements than anti-NMDAR antibody (+)/MOG antibody (-) patients and had a significantly higher incidence of sleep disorders, seizures, and psycho-behavioral abnormalities than MOG antibody (+)/anti-NMDAR antibody (-) patients. The MNOS patients had a significantly higher incidence of MRI abnormalities than the anti-NMDAR antibody (+)/MOG antibody (-) patients, while there was no significant difference in the incidence between the MNOS patients and the MOG antibody (+)/anti-NMDAR antibody (-) patients. No significant difference was seen in the initial mRS score between the three groups of patients. The anti-NMDAR antibody (+)/MOG antibody (-) patients had a higher rate of admission to the ICU, a longer length of in-hospital stay, and a higher rate of introduction to second-line treatment than the other two groups of patients. No significant difference was seen in the mRS score at the last follow-up and in the disease recurrence rate between the three groups. All these patients respond well to immunosuppressive therapy.

Discussion

In the presence of psycho-behavioral abnormalities, sleep disorders, and frequent seizures in MOG-AD patients or demyelinating symptoms of the central nervous system or demyelinating lesions on head MRI in anti-NMDAR encephalitis patients, the coexistence of MOG and anti-NMDAR antibodies should be considered and would suggest a diagnosis of MNOS for these patients. Immunotherapy is effective among these patients and should be given possibly earlier.

Clinical and radiological features, treatment responses and prognosis in pediatric patients with co-existing anti-N-methyl-D-aspartate receptor and myelin oligodendrocyte glycoprotein antibody-associated encephalitis: A single center study

OBJECTIVES

To characterize the clinical and radiological features, treatment responses and outcomes of children with co-existing anti-N-methyl-D-aspartate receptor(NMDAR) and myelin oligodendrocyte glycoprotein(MOG) antibody-associated encephalitis.

METHODS

Clinical manifestations, imaging features, effectiveness of treatment and outcomes of patients who were cerebral spinal fluid(CSF)-positive for NMDAR-antibody(NMDAR-ab) and seropositive for MOG-antibody(MOG-ab) were analyzed.

RESULTS

Twelve patients including 8 females and 4 males were enrolled. The median onset age was 9 years, ranging from 2.2 to 12.8 years. Behavioral changes and/or psychiatric symptoms (n = 8/12), seizures (n = 8/12), encephalopathy (n = 7/12) were 3 of the most common symptoms. Brain magnetic resonance imaging(MRI) of all the patients showed T2/fluid attenuation inversion recovery(FLAIR) abnormal signal in the cerebral white matter at least once in the courses of disease, 2 of whom developed new brain lesions which were asymptomatic. All of the patients had supratentorial lesions. Spinal cord MRI was performed in 7 patients. Only 1 patient showed related abnormalities with increased T2 signal in the spinal cord C1-5. Nine patients underwent optic nerve MRI; 5 patients demonstrated abnormal results, among whom 4 exhibited T2 abnormal signal (2 were symptom-free) and 1 showed a little effusion in bilateral optic nerve sheats. Intravenous immunoglobulin (IVIG) and intravenous methylprednisolone (IVMP) were the most common used therapies in those patients. Nine patients were treated with second-line therapy to prevent relapses. For total 29 clinical attacks, the median modified Rankin Scale (mRS) before treatment and after therapy of acute stage was 1 and 0, respectively. Seven of 12 patients(58.3 %) experienced clinical relapses. In terms of outcome, all of the patients' mRS of last follow-up (≥6 months) was ≤2.

CONCLUSIONS

Behavioral changes and/or psychiatric symptoms, seizures and encephalopathy were common in children with co-existing anti-NMDAR and MOG antibody-associated encephalitis. A minority of subjects may develop asymptomatic lesions on brain and optic nerve MRI. The relapse rate of this disease is relatively high. The majority of patients responded well to the immunotherapies and had a good outcome(mRS of last follow-up≤2).

Pediatric anti-NMDAR encephalitis with demyelination on brain MRI: A single center study

OBJECTIVE

To explore the clinical characteristics, immunotherapy response, and prognosis of pediatric anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis associated with demyelination on brain magnetic resonance (MRI).

METHODS

We retrospectively reviewed the medical records of children diagnosed with anti-NMDAR encephalitis in our hospital between January 2016 and December 2021. All children with evidence of demyelination on brain MRI were included.

RESULTS

A total of 183 anti-NMDAR encephalitis children were included; 8.7 % (16/183) of them had demyelination on brain MRI. Nine were positive for myelin oligodendrocyte glycoprotein (MOG)-IgG, while two were positive for both MOG-IgG and glial fibrillary acidic protein (GFAP)-IgG. Four patients had a history of acquired demyelinating syndromes and encephalitis, respectively, while nine (56.3 %) had atypical symptoms of anti-NMDAR encephalitis. All children had supratentorial demyelination on brain MRI; four of them had additional infratentorial lesions. All children received first-line immunotherapy; four were administered repeated first-line immunotherapy and/or rituximab because of poor initial response. During the follow-up, 37.5 % (6/16) of the children relapsed, but all responded well to immunotherapy. There were no significant differences in mRS score before immunotherapy, response to first-line immunotherapy, and long-term prognosis between anti-NMDAR encephalitis children with and without demyelination. However, patients with demyelination were more likely to have a history of acquired demyelinating syndromes or unexplained cortical encephalitis and to relapse.

CONCLUSION

Pediatric anti-NMDAR encephalitis can co-occur with demyelination and has a high rate of MOG-IgG positivity. A history of acquired demyelinating syndromes or unexplained cortical encephalitis and atypical symptoms may indicate demyelination in children with anti-NMDAR encephalitis. Pediatric anti-NMDAR encephalitis with demyelination is more likely to relapse and needs a closer follow-up. However, it remains unknown whether more intensive immunotherapy is required in these patients.

Clinical risk factors for recurrence of myelin oligodendrocyte glycoprotein antibody-associated disease

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a CNS demyelinating disease that targets myelin oligodendrocyte glycoprotein and recurs in approximately 50% of patients after the initial episode. Multiple relapses may have adverse consequences, but the factors influencing relapse are unclear. This study analyzed the clinical risk factors for relapse in patients with MOGAD.

METHODS

Twenty-four MOGAD patients diagnosed at the Department of Neurology, First Hospital of Shanxi Medical University from March 2018 to November 2020 were retrospectively analyzed in this study. The patients were divided into a monophasic course and a relapsing course according to their disease process. The patients' epidemiological characteristics, clinical symptoms, laboratory tests, imaging features, and regression were summarized. Comparisons were made between the monophasic and relapsing course to identify the possible factors associated with the clinical features and recurrence.

RESULTS

At a mean follow-up of 15 months (range: 8 to 24 months), seventeen of the 24 patients (70.8%) had monophasic disease, and 7 (29.2%) had relapsing disease. Among the 24 patients, 17 patients (70.9%) had low Myelin oligodendrocyte glycoprotein antibody (MOG-IgG) serum titers (<1:100), and 7 patients (29.1%) had high MOG-IgG serum titers (≥1:100). Compared to the monophasic course group, patients in the relapsing course group had higher serum antibody titers (71.4% vs. 11.7%, P = 0.035). Onset phenotypes included encephalitis (50%), myelitis (45.8%), and optic neuritis (45.8%), with 66.7% of patients starting with a single phenotype and 33.3% starting with two or more phenotypes. Optic neuritis was more common in the relapsing course group (85.7%) than the monophasic course group (29.4%) (P = 0.023). There was no significant difference between the two groups in the proportion of myelitis and encephalitis. A previous history or background of immunological disease was present in 33.3% of patients, with a significantly higher proportion in the relapsing course group than in the monophasic course group (71.4% vs. 17.6%, P = 0.021). Regarding ancillary examinations, the relapsing course group was more likely to have CSF leukocytes higher than 50/mm3 than the monophasic course group (60% vs. 0, P = 0.045), while there was no difference in the number and site distribution of the lesions on MRI.

CONCLUSIONS

Our study suggests that the most common clinical manifestations of MOGAD are diminished visual acuity, limb/facial numbness, and ocular/orbital pain. The onset phenotype consisting of optic neuritis, a history of immune disease, high antibody titers (≥1:100), and high cerebrospinal fluid leukocytes (above 50/mm3) suggests a high likelihood of MOGAD recurrence.

Clinical features of MOGAD with brainstem involvement in the initial attack versus NMOSD and MS

OBJECTIVE

To assess the characteristics of Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disorder (MOGAD) with brainstem involvement in the first event (BSIFE) and make comparisons with aquaporin-4-IgG seropositive neuromyelitis optica spectrum disorder (AQP4-IgG-NMOSD) and multiple sclerosis (MS).

METHODS

From 2017 to 2022, this study identified MOG-IgG-positive patients with brainstem or both brainstem and cerebellum lesions in the first episode. As a comparison group, AQP4-IgG-NMOSD (n = 30) and MS (n = 30) patients with BSIFE were enroled.

RESULTS

Thirty-five patients (35/146, 24.0%) were the BSIFE of MOGAD. Isolated brainstem episodes occurred in 9 of the 35 (25.7%) MOGAD patients, which was similar to MS (7/30, 23.3%) but was lower than AQP4-IgG-NMOSD (17/30, 56.7%, P = 0.011). Pons (21/35, 60.0%), medulla oblongata (20/35, 57.1%) and middle cerebellar peduncle (MCP, 19/35, 54.3%) were the most frequently affected areas. Intractable nausea (n = 7), vomiting (n = 8) and hiccups (n = 2) happened in MOGAD patients, but EDSS of MOGAD was lower than AQP4-IgG-NMOSD (P = 0.001) at the last follow-up. MOGAD patients with or without BSIFE did not significantly differ in terms of the ARR (P = 0.102), mRS (P = 0.823), or EDSS (P = 0.598) at the most recent follow-up. Specific oligoclonal bands appeared in MOGAD (13/33, 39.4%) and AQP4-IgG-NMOSD (7/24, 29.2%) in addition to MS (20/30, 66.7%). Fourteen MOGAD patients (40.0%) experienced relapse in this study. When the brainstem was involved in the first attack, there was an increased likelihood of a second attack occurring at the same location (OR=12.22, 95%CI 2.79 to 53.59, P = 0.001). If the first and second events were both in the brainstem, the third event was likely to occur at the same location (OR=66.00, 95%CI 3.47 to 1254.57, P = 0.005). Four patients experienced relapses after the MOG-IgG turned negative.

CONCLUSION

BSIFE occurred in 24.0% of MOGAD. Pons, medulla oblongata and MCP were the most frequently involved regions. Intractable nausea, vomiting and hiccups occurred in MOGAD and AQP4-IgG-NMOSD, but not MS. The prognosis of MOGAD was better than AQP4-IgG-NMOSD. In contrast to MS, BSIFE may not indicate a worse prognosis for MOGAD. When patients with BSIFE, MOGAD tent to reoccur in the brainstem. Four of the 14 recurring MOGAD patients relapsed after the MOG-IgG test turned negative.

The case report of MOG and NMDAR IgG double positive encephalitis treated with subcutaneous ofatumumab

The phenotypic spectrum of myelin oligodendrocyte glycoprotein (MOG)- IgG-associated disorders (MOGAD) has broadened in the past few years, and atypical phenotypes are increasingly recognized. Isolated seizures and MRI-negative brainstem and cerebellar symptoms or encephalitis have rarely been reported as a feature of MOGAD and represent a diagnostic challenge. Meanwhile, the coexistence of MOG IgG and other CNS autoimmune antibodies is infrequent. We report a patient presented with isolated epileptic onset, relapsed with MRI-negative brainstem symptoms and MRI-negative encephalitis. He was positive for MOG IgG throughout the disease course while concomitant NMDAR IgG was not detected positive until second relapse. He showed decreasing response to conventional first-line therapy. The last relapse was during a COVID-19 epidemic with limited inpatient resources. Fortunately, he was ultimately controlled on subcutaneous ofatumumab, a novel fully humanized anti-CD20 mAb. This is the first report about subcutaneous ofatumumab treatment in MOG and NMDAR IgG double positive encephalitis with 12-month follow-up, depicting its potential as a therapeutic option.

Long-term efficacy and safety of different corticosteroid courses plus mycophenolate mofetil for autoimmune encephalitis with neuronal surface antibodies without tumor

Objective

To compare the efficacy and safety of different-course corticosteroids plus mycophenolate mofetil (MMF) as maintenance therapy in autoimmune encephalitis (AE) with neuronal surface antibodies (NSAbs) without tumor and explore the optimal course of corticosteroids.

Methods

Fifty-five patients with definite AE without tumor were enrolled consecutively between June 2015 and November 2020 and retrospectively divided three groups according to the course of treatment with corticosteroid, i.e., a group of patients with a course of 3-6 months (Group 3-6mo), 6-12 months (Group 6-12mo), and >12 months (Group >12mo). Demographic data, clinical manifestation and ancillary tests results were recorded. The dosage and courses of corticosteroid treatment, the recovery of neurological function, the occurrence of adverse effects, and relapses were followed up.

Results

A total of 55 patients were included in the final analysis. The numbers of patients in Group 3-6 mo, Group 6-12 mo, and Group >12 mo was 14, 17, and 24, respectively. A significantly higher proportion of patients in Group >12 mo showed a decreased level of consciousness at the onset (12, 50%) than in Group 3-6 mo and Group 6-12 mo (2,14.3%; 3, 17.6%) (p = 0.033). The incidence of MRI abnormalities was significantly higher in Group 6-12 mo and Group >12 mo (10, 58.8%; 16, 66.7%) than in Group 3-6 mo (3, 21.4%) (P=0.023). Ordinal regression analysis indicated that decreased level of consciousness was associated with the course of corticosteroid (OR=3.838, 95% CI: 1.103-13.323, P=0.035). No significant difference was observed between the three groups regarding the cumulative dose of corticosteroids administered during the first three months of long-term treatment (P>0.05). Additionally, no significant difference in the cumulative dosage of corticosteroids was found between patients in Group 6-12 months and Group >12 months during the first 6 months after beginning long-term treatment. The mRS scores of the three groups were not statistically significant before and after first-line treatment or at the last follow-up. Bonferroni multiple comparison test indicated that the mRS scores of patients in Group 6-12 months and Group >12 months were not statistically significant at 3 months and 12 months after the start of long-term treatment. During the follow-up, 50 (90.9%) patients achieved satisfactory neurological function (mRS score ≤2). Five patients (9.1%) experienced a first relapse and 2 of them were overlapped with both anti-NMDA receptor and glial antibodies. The incidence of adverse effects was significantly higher in Group >12 mo (17, 70.8%) than in Group 3-6 mo (3, 21.4%) and Group 6-12 mo (5, 29.4%) (P=0.003).

Conclusions

The beneficial effects of oral corticosteroid treatment may do not persist beyond 12 months and may even contribute to an increased incidence of adverse effects. In order to optimize the effectiveness and safety of treatment, we recommend a corticosteroid course of 3-12 months. Patients with reduced levels of consciousness may be more inclined to choose longer courses of corticosteroids for long-term treatment. Patients with an "overlapping syndrome" may require more intense immunotherapy to prevent relapse.

Myelin Oligodendrocyte Glycoprotein (MOG) Associated Diseases: Updates in Pediatric Practice

Myelin oligodendrocyte glycoprotein (MOG) is a membrane bound protein found on the surface of oligodendrocyte cells and the outermost surface of myelin sheaths. MOG is posited to play a role as a cell surface receptor or cell adhesion molecule, though there is no definitive answer to its exact function at this time. In the last few decades, there has been a recognition of anti-MOG-antibodies (MOG-Abs) in association with a variety of neurologic conditions, though primarily demyelinating and white matter disorders. In addition, MOG associated disease (MOGAD) appears to have a predilection for pediatric populations and in some patients may have a relapsing course. There has been considerable debate as to whether MOG-Abs are truly directly pathogenic or a disease biomarker associated with neuorinflammatory disease. In this manuscript we will review the current literature surrounding MOGAD, review new clinical phenotypes, discuss treatment and prognosis, and provide insight into potential future directions that studies may focus on.

Diagnosis of myelin oligodendrocyte glycoprotein antibody-associated disease: International MOGAD Panel proposed criteria

Serum antibodies directed against myelin oligodendrocyte glycoprotein (MOG) are found in patients with acquired CNS demyelinating syndromes that are distinct from multiple sclerosis and aquaporin-4-seropositive neuromyelitis optica spectrum disorder. Based on an extensive literature review and a structured consensus process, we propose diagnostic criteria for MOG antibody-associated disease (MOGAD) in which the presence of MOG-IgG is a core criterion. According to our proposed criteria, MOGAD is typically associated with acute disseminated encephalomyelitis, optic neuritis, or transverse myelitis, and is less commonly associated with cerebral cortical encephalitis, brainstem presentations, or cerebellar presentations. MOGAD can present as either a monophasic or relapsing disease course, and MOG-IgG cell-based assays are important for diagnostic accuracy. Diagnoses such as multiple sclerosis need to be excluded, but not all patients with multiple sclerosis should undergo screening for MOG-IgG. These proposed diagnostic criteria require validation but have the potential to improve identification of individuals with MOGAD, which is essential to define long-term clinical outcomes, refine inclusion criteria for clinical trials, and identify predictors of a relapsing versus a monophasic disease course.

Aquaporin-4 Antibody Dynamics and Relapse Risk in Seropositive Neuromyelitis Optica Spectrum Disorder Treated with Immunosuppressants

OBJECTIVE

To investigate aquaporin-4 antibody (AQP4-IgG) dynamics and relapse risk in patients with seropositive neuromyelitis optica spectrum disorder treated with immunosuppressants.

METHODS

This observational cohort study with prospectively collected data included 400 neuromyelitis optica spectrum disorder patients seropositive for AQP4-IgG and treated with immunosuppressants. Serum AQP4-IgG was detected by fixed cell-based assay every 6 months.

RESULTS

After treatment with immunosuppressants, 128 patients became AQP4-IgG seronegative. The median time to become seronegative for 400 patients was 76.4 months (61.4 months, NA). Among those patients with negative change of AQP4-IgG, the mean annualized relapse rate significantly decreased after patients became seronegative (0.20 vs 0.77, p < 0.001), and a positive correlation was observed between time to become seronegative and relapse (OR 1.018, 95% CI 1.001-1.035, p < 0.05). Independent risk factors for AQP4-IgG becoming seronegative were older age at onset, initiation of immunosuppressants at onset, and shorter disease duration before maintenance therapy. Independent risk factors for relapse included younger age (≤46.4 years) at onset, poly-system involvement in the first attack, and unchanged or increased AQP4-IgG titer. The relapse risk was not associated with sex, combination with connective tissue disease, seropositivity for systemic autoimmune antibodies, or incomplete recovery from the first attack.

INTERPRETATION

Patients with younger age at onset, poly-system involvement in the first attack, and unchanged or increased titer of AQP4-IgG are most likely to experience relapse under treatment with immunosuppressants. Time to AQP4-IgG becoming seronegative and change of AQP4-IgG titer may become the surrogate efficacy biomarkers in clinical trials. ANN NEUROL 2023.

FLAIR-hyperintense lesions in anti-MOG-associated encephalitis with seizures overlaying anti-N-methyl-D-aspartate receptor encephalitis: a case report and literature review

Background

FLAIR-hyperintense lesions in anti-MOG-associated encephalitis with seizures (FLAMES) has been identified increasingly frequently in recent years. However, this rare MOG antibody disease may coexist with anti-N-methyl-D-aspartate receptor encephalitis (anti-NMDARe), in an overlap syndrome with unknown clinical features and prognosis.

Methods

We report a new case of this overlap syndrome and present a systematic review of similar cases in the literature to provide information on the clinical presentation, MRI features, EGG abnormalities, treatment, and prognosis of patients with this rare syndrome.

Results

A total of 12 patients were analyzed in the study. The most common clinical manifestations of FLAMES overlaid with anti-NMDARe were epilepsy (12/12), headache (11/12), and fever (10/12). Increases in intracranial pressure (median: 262.5 mmH₂O, range: 150-380 mmH₂O), cerebrospinal fluid (CSF) leukocyte count (median: 128×10⁶/L, range: 1-610×10⁶/L), and protein level (median: 0.48 g/L) were also observed. The median CSF anti-NMDAR antibody titer was 1:10 (1:1-1:32), while the median serum MOG antibody titer was 1:32 (1:10-1:1024). Seven cases exhibited unilateral cortical FLAIR hyperintensity, and five cases (42%) had bilateral cortical FLAIR hyperintensity, including four cases involving the bilateral medial frontal lobes. Of the 12 patients, five showed lesions at other sites (e.g., the brainstem, corpus callosum, or frontal orbital gyrus) before or after the development of cortical encephalitis. EEG showed slow waves in four cases, spike-slow waves in two cases, an epileptiform pattern in one case, and normal waves in two cases. The median number of relapses was two. Over a mean follow-up period of 18.5 months, only one patient experienced residual visual impairment, while the remaining 11 patients had good prognoses.

Conclusion

FLAMES alone is difficult to distinguish from overlap syndrome based on clinical features. However, FLAMES with bilateral medial frontal lobe involvement suggests the presence of the overlap syndrome.

Efficacy and safety of rituximab in myelin oligodendrocyte glycoprotein antibody-associated disorders compared with neuromyelitis optica spectrum disorder: a systematic review and meta-analysis

BACKGROUND

Rituximab (RTX) efficacy in patients with myelin oligodendrocyte glycoprotein (MOG) antibody-associated disorders (MOGADs) is still poorly understood, though it appears to be lower than in aquaporin-4-IgG-positive neuromyelitis optica spectrum disorders (AQP4-IgG+NMOSDs). The aim of this systematic review and meta-analysis is to assess the efficacy and safety profile of RTX in patients with MOGAD and to compare RTX efficacy between MOGAD and AQP4-IgG+NMOSD.

METHODS

We searched original English-language articles published between 2012 and 2021 in MEDLINE, Cochrane, Central Register of Controlled Trials and clinicaltrials.gov, reporting data on RTX efficacy in patients with MOGAD. The main outcome measures were annualised relapse rate (ARR) and Expanded Disability Status Scale (EDSS) score mean differences (MDs) after RTX. The meta-analysis was performed with a random effects model. Covariates associated with the outcome measures were analysed with a linear meta-regression.

RESULTS

The systematic review included 315 patients (138 women, mean onset age 26.8 years) from 32 studies. Nineteen studies (282 patients) were included in the meta-analysis. After RTX, a significant decrease of ARR was found (MD: -0.92, 95% CI -1.24 to -0.60, p<0.001), markedly different from the AQP4-IgG+NMOSD (MD: -1.73 vs MOGAD -0.92, subgroup difference testing: Q=9.09, p=0.002). However, when controlling for the mean ARR pre-RTX, this difference was not significant. After RTX, the EDSS score decreased significantly (MD: -0.84, 95% CI -1.41 to -0.26, p=0.004). The frequency of RTX-related adverse events was 18.8% (36/192) and overall RTX-related mortality 0.5% (1/192).

CONCLUSIONS

RTX showed effective in MOGAD, although to a lesser extent than in AQP4-IgG+NMOSD, while the safety profile warrants some caution in its prescription. Randomised-controlled trials are needed to confirm these findings and provide robust evidence to improve treatment strategies in patients with MOGAD.

PROSPERO REGISTRATION NUMBER

CRD42020175439.

[Clinical characteristics and short-term outcomes of autoimmune encephalitis in adults]

OBJECTIVE

To characterize clinical, paraclinical features and short-term outcomes in different types of autoimmune encephalitis (AE) in a one-center cohort of Russian patients, as well as to evaluate the frequency and significance of the joint expression of antineuronal and anti-glial antibodies (Abs) in AE.

MATERIAL AND METHODS

Forty-one patients were diagnosed with AE at the Research Center of Neurology from November 2020 to December 2022. Demographic, clinical characteristics, results of laboratory tests, MRI of brain, treatment and outcomes of disease were analyzed. The analysis of Abs to glial antigens (myelin-oligodendrocyte glycoprotein - MOG, glial fibrillar acidic protein - GFAP, aquaporin 4 - AQP-4) was performed by indirect immunofluorescence assay (Euroimmun, Germany).

RESULTS

In 24 (58.5%) patients was established definite AE, confirmed by specific Abs detection; in 2 (4.9%) - definite limbic encephalitis, in 15 (36.6%) - seronegative probable AE (including 3 cases of Hashimoto's encephalitis). GFAP-Abs in cerebrospinal fluid (CSF) were detected only in two patients - with clinical and MRI-picture of autoimmune GFAP-astrocytopathy (A-GFAP-A). GFAP- and MOG-Abs in the blood were detected in 25.7% and 6%, respectively, AQP-4-Abs were not detected. There were no correlations between co-expression with glial Abs and clinical characteristics. Systemic and antithyroid Abs were present in 15% and 31%, respectively. Paraneoplastic AE accounted for 22%. For the first time in the Russian population, 2 cases of A-GFAP-A, 6 cases of AE associated with COVID-19 were described. The most common first syndrome were epileptic seizure (34%), psychiatric (29%) and cognitive (14%) disorders. Relapses of AE was observed in 22%. Inflammatory changes in CSF were detected in 41%, focal changes on MRI in 68%. First-line immune therapy was performed in all patients, 85% of cases received pulse therapy with methylprednisolone. Second-line immune therapy (rituximab or cyclophosphamide intravenously) was performed in 19.5%, 78% of patients achieved significant improvement during treatment (scores ≤2 on the modified Rankin scale).

CONCLUSIONS

The results allow us to consider COVID-19 as a trigger of AE. The absence of detection of GFAP-Abs in CSF in patients with other types of AE contributes to the confirmation of the specificity of GFAP-seropositivity of CSF for the diagnosis of A-GFAP-A. The expression of GFAP- and MOG-Abs in AE can serve as confirmation of the immuno-mediated etiology of the disease, which is especially important for the AE diagnosis in the absence of antineuronal Abs.

Clinical characteristics and prognosis of pediatric myelin oligodendrocyte glycoprotein antibody-associated diseases in China

BACKGROUND

Research on myelin oligodendrocyte glycoprotein antibody (MOG-Ab)-associated disease (MOGAD) among Chinese children is relatively rare. Therefore, this study aimed to explore and analyze the clinical characteristics and prognoses of Chinese children with acquired demyelinating syndromes (ADSs) who tested positive or negative for MOG-Ab.

METHODS

The clinical data of children with MOGAD who were treated in the Department of Neurology at Shanghai Children's Hospital from January 2017 to October 2021 were retrospectively collected.

RESULTS

Among 90 children with ADSs, 30 were MOG-Ab-positive, and 60 were MOG-Ab-negative. MOG-Ab-positive children experienced more prodromal infections than did MOG-Ab-negative children (P < 0.05). Acute disseminated encephalomyelitis was the most common ADSs in both groups. There were ten cases of a rebound increase in MOG-Ab titers. There were significant differences in the MOG titer-related prognosis and disease time course between the disease relapse group and the non-relapse group (P < 0.01). Among the MOG-Ab-positive patients, the most affected brain areas detected via magnetic resonance imaging (MRI) were the temporal lobe, cerebellar hemispheres, brainstem, and periventricular lesions. The most common shapes of the lesions were commas, triangles, or patches. The average improvement time based on brain MRI was much longer in MOG-Ab-positive than in MOG-Ab-negative children (P < 0.05). The initial treatment time correlated with the disease time course, and the prognosis may be affected by the disease time course and serum MOG-Ab titer (P < 0.05).

CONCLUSION

The clinical characteristics and imaging features of ADSs differed between MOG-Ab-positive and MOG-Ab-negative children. In addition to existing treatment plans, additional diagnoses and treatment plans should be developed to reduce recurrence and improve the prognoses of children with MOGAD.

Anti-NMDA receptor encephalitis and MOG-associated demyelination - a case report with long-term follow-up and a systematic review

BACKGROUND

Overlap syndromes of anti-NMDA receptor encephalitis and MOG-mediated demyelination have been reported. In this case we provide a long-term longitudinal follow-up of clinical and imaging characteristics as well as of antibody dynamics.

CASE PRESENTATION

We report a 32-year-old male patient who presented with psychosis, decreased consciousness and movement disorders and was tested positive for anti-NMDA receptor antibodies. Forty-four months after symptom onset and diagnosis of autoimmune encephalitis, he suffered from relapse. At this time, the patient developed anti-MOG and anti-Caspr2 antibodies. Treatment with plasmapheresis, steroids and rituximab eventually led to substantial clinical and radiological improvement. Anti-Caspr2 antibodies persisted, anti-NMDA receptor antibodies decreased, while anti-MOG antibodies turned negative again.

CONCLUSION

We provide long-term longitudinal follow-up of a patient with anti-NMDA receptor encephalitis who developed triple antibody positivity at the time of relapse. Antibody dynamics were associated with clinical disease course.

Autoimmune diseases and cancers overlapping with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD): A systematic review

Background

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) has various similarities with AQP4-IgG-seropositive Neuromyelitis Optica Spectrum Disorder (AQP4-IgG + NMOSD) in terms of clinical presentations, magnetic resonance imaging (MRI) findings, and response to treatment. But unlike AQP4-IgG + NMOSD, which is known to coexist with various autoimmune diseases and cancers, an association of MOGAD with these conditions is less clear.

Methods

We conducted a systematic search in PubMed, Scopus, Web of Science, and Embase based on the preferred reporting items for systematic reviews and meta-analysis (PRISMA). Duplicates were removed using Mendeley 1.19.8 (USA production) and the citations were uploaded into Covidence systematic review platform for screening.

Results

The most common autoimmune disease overlapping with MOGAD was anti-N-Methyl-D-Aspartate receptor encephalitis (anti-NMDAR-EN), followed by autoimmune thyroid disorders, and the most common autoantibody was antinuclear antibody (ANA), followed by AQP4-IgG (double-positive MOG-IgG and AQP4-IgG). A few sporadic cases of cancers and MOG-IgG-associated paraneoplastic encephalomyelitis were found.

Conclusion

Unlike AQP4-IgG + NMOSD, MOGAD lacks clustering of autoimmune diseases and autoantibodies associated with systemic and organ-specific autoimmunity. Other than anti-NMDAR-EN and perhaps AQP4-IgG + NMOSD, the evidence thus far does not support the need for routine screening of overlapping autoimmunity and neoplasms in patients with MOGAD.

Coexistence of multiple anti-neuronal antibodies in autoimmune encephalitis in China: A multi-center study

Background

Given that the combination of multiple antibodies in autoimmune encephalitis (AE) is rare and its clinical significance is unclear, this study aimed to investigate the clinical characteristics and significance of overlapping multiple anti-neuronal antibodies in patients with AE.

Methods

We conducted a retrospective analysis of the clinical characteristics, treatment, and prognostic details of 22 patients with multiple coexisting antibodies from multiple clinical centers in China.

Results

Among the 276 patients who were AE antibody-positive, 22 (7.97%) had two or more antibodies. Among the 22 patients with coexisting AE-related antibodies, 14 patients (63.63%) were combined of cell surface and intracellular antibody, and the remaining 8 patients (36.36%) were detected to be cell surface antibody positive only. The main symptoms of the 22 patients in this cohort included fever, seizures, memory impairment, cognitive decline, and sleep disorders. Five (22.73%) patients had tumors, among whom four had small-cell lung cancers, and one had mediastinal tumors. A total of 20 patients were treated with steroids and intravenous immunoglobulin, and 18 showed varying degrees of symptomatic improvement after first-line immunotherapy. Three patients died of tumor progression or chemotherapy complications.

Conclusion

The coexistence of multiple anti-neuronal antibodies in patients with AE may cause a superimposition and diversification of clinical manifestations. Combined paraneoplastic antibody positivity may be suggestive of an underlying malignancy.

Overlapping Autoimmune Neurological Syndrome: A Case Report of Triple-Positive Antibody

The presentation of several autoimmune neurological disorders in a single patient is rare and often debilitating. However, early diagnosis and efficacious treatment can lead to a significant recovery. Here, we present an interesting case of a triple antibody-positive autoimmune neurological syndrome patient who manifested the clinical features of neuromyelitis optica (NMO) spectrum disorder (NMOSD), N-methyl-D-aspartate (NMDA) receptor (NMDAR) encephalitis, and myasthenia gravis (MG). Hence, the patient manifested both central and peripheral nervous system immune-mediated neurological syndromes. A middle-aged female with a history of seropositive aquaporin-4 (AQP4) NMOSD on mycophenolate 1 g twice daily presented with severe fatigue and right eye ptosis (three months since NMOSD diagnosis) and tested positive for acetylcholine receptor (AchR) binding antibody, consistent with MG. Six months after the patient’s NMOSD diagnosis, she began to experience subacute progressive cognitive decline, behavioral changes, imbalance, anxiety/panic attacks, and paranoid delusions. NMDAR encephalitis was suspected, and she tested positive for cerebrospinal fluid NMDAR antibodies. After treatment with steroids failed, she was given two doses of rituximab 1 g, two weeks apart, and reported improvement in her symptoms shortly after the second dose.

Coexistence of Myelin Oligodendrocyte Glycoprotein Immunoglobulin G and Neuronal or Glial Antibodies in the Central Nervous System: A Systematic Review

Background: Myelin oligodendrocyte glycoprotein immunoglobulin G (MOG-IgG) has been considered a diagnostic marker for patients with demyelinating disease, termed “MOG-IgG associated disorder” (MOGAD). Recently, the coexistence of MOG-IgG and other neuronal or glial antibodies has attracted extensive attention from clinicians. In this article, we systematically review the characteristics of MOG-IgG-related antibody coexistence syndrome. Methods: Two authors independently searched PubMed for relevant studies published before October 2021. We also manually searched the references of each related article. The appropriateness of the included studies was assessed by reading the titles, abstracts, and full texts if necessary. Results: Thirty-five relevant publications that met our inclusion criteria were finally included, of which fourteen were retrospective studies and twenty-one were case reports. A total of 113 patients were reported to show the coexistence of MOG-IgG and neuronal or glial antibodies. Additionally, 68.14% of patients were double positive for MOG-IgG and N-Methyl-D-Aspartate Receptor-IgG (NMDAR-IgG), followed by 23.01% of patients who were double positive for MOG-IgG and aquaporin4-IgG (AQP4-IgG). Encephalitis was the predominant phenotype when MOG-IgG coexisted with NMDAR-IgG, probably accompanied by imaging features of demyelination. Patients with dual positivity for MOG-IgG and AQP4-IgG experienced more severe disease and more frequent relapses. The coexistence of MOG-IgG and antibodies other than NMDAR-IgG and AQP4-IgG was extremely rare, and the clinical presentations were diverse and atypical. Except for patients who were double positive for MOG-IgG and AQP4-IgG, most patients with multiple antibodies had a good prognosis. Conclusions: MOG-IgG may coexist with neuronal or glial antibodies. Expanded screening for neuronal or glial antibodies should be performed in patients with atypical clinical and radiological features.

Clinical Characteristics of Anti-N-Methyl-d-Aspartate Receptor Encephalitis Overlapping with Demyelinating Diseases: A Review

Anti-N-methyl-d-aspartate receptor encephalitis (NMDARe), a common autoimmune encephalitis, can be accompanied by demyelinating disorders, including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). To compare the clinical characteristics of patients with different overlapping syndromes, we searched the PubMed database and performed a systematic review. Of the 79 patients with overlapping syndromes, 15 had MS, 18 had aquaporin-4-antibody-positive NMOSD (AQP4-Ab-positive NMOSD), and 46 had MOGAD. Compared with classical NMDARe, overlapping syndromes showed atypical symptoms, such as limb weakness, sensory disturbance, and visual impairments in addition to the main symptoms of NMDARe and a lower ratio of ovarian teratoma. Patients with MOGAD overlap were the youngest, while patients with MS and AQP4-Ab-positive NMOSD overlap tended to be older than patients with classical NMDARe. A majority of patients with NMDARe who overlapped with MS or AQP4-Ab-positive NMOSD were female, but this was not the case for patients overlapped with MOGAD. When NMDARe and demyelinating diseases occurred sequentially, the interval was the longest in patients with NMDARe overlapped with MS. A favorable outcome was observed in patients overlapping with MOGAD, but no robust comparison can be drawn with the patients overlapping with AQP4-Ab-positive NMOSD and MS regarding the small number of available data. The long-term prognosis of overlapping syndromes needs further investigation.

Overlapping syndrome of recurrent anti-N-methyl-D-aspartate receptor encephalitis and anti-myelin oligodendrocyte glycoprotein demyelinating diseases: A case report

BACKGROUND

Anti-N-methyl-D-aspartate receptor encephalitis (NMDARe) is capable of presenting a relapsing course and coexisting with myelin oligodendrocyte glycoprotein antibody disease, whereas it has been relatively rare. We describe a man with no history of tumor who successively developed anti-NMDARe and anti-myelin oligodendrocyte glycoprotein antibody disease.

CASE SUMMARY

A 29-year-old man was initially admitted with headache, fever, intermittent abnormal behavior, decreased intelligence, limb twitching and loss of consciousness on July 16, 2018. On admission, examination reported no abnormality. During his presentation, he experienced aggravated symptoms, and the re-examination of cranial magnetic resonance imaging (MRI) indicated punctate abnormal signals in the left parietal lobe. External examination of cerebrospinal fluid and serum results revealed serum NMDAR antibody (Ab) (-), cerebrospinal fluid NMDAR-Ab (+) 1:10 and Epstein-Barr virus capsid antigen antibody IgG (+). Due to the imaging findings, anti-NMDARe was our primary consideration. The patient was treated with methylprednisolone and gamma globulin pulse therapy, mannitol injection dehydration to reduce intracranial pressure, sodium valproate sustained-release tablets for anti-epilepsy and olanzapine and risperidone to mitigate psychiatric symptoms. The patient was admitted to the hospital for the second time for “abnormal mental behavior and increased limb movements” on December 14, 2018. Re-examination of electroencephalography and cranial MRI showed no abnormality. The results of autoimmune encephalitis antibody revealed that serum NMDAR-Ab was weakly positive and cerebrospinal fluid NMDAR-Ab was positive. Considering comprehensive recurrent anti-NMDARe, the patient was treated with propylene-hormone pulse combined with immunosuppressive agents (mycophenolate mofetil), and the symptoms were relieved. The patient was admitted for “hoarseness and double vision” for the third time on August 23, 2019. Re-examination of cranial MRI showed abnormal signals in the medulla oblongata and right frontal lobe, and synoptophore examination indicated concomitant esotropia. The patient’s visual acuity further decreased, and the re-examination of cranial MRI + enhancement reported multiple scattered speckled and patchy abnormal signals in the medulla oblongata, left pons arm, left cerebellum and right midbrain, thalamus. The patient was diagnosed with an accompanying demyelinating disease. Serum anti-myelin oligodendrocyte glycoprotein 1:10 and NMDAR antibody 1:10 were both positive. The patient was diagnosed with myelin oligodendrocyte glycoprotein antibody-related inflammatory demyelinating disease of the central nervous system complicated with anti-NMDARe overlap syndrome. The patient was successfully treated with methylprednisolone, gamma globulin pulse therapy and rituximab treatment. The patient remained asymptomatic and follow-up MRI scan 6 mo later showed complete removal of the lesion.

CONCLUSION

We emphasize the rarity of this antibody combination and suggest that these patients may require longer follow-up due to the risk of recurrence of two autoimmune disorders.

Overlapping anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis with neuromyelitis optica spectrum disorders: a case report

Background

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis can coexist with neuromyelitis optica spectrum disorder (NMOSD). Patients with overlapping anti-NMDAR encephalitis with positive NMDAR antibodies and aquaporin 4 immunoglobulin G (AQP4-IgG)-seropositive NMOSD are rare but should not be ignored.

Case presentation

This report describes a unique case of anti-NMDAR encephalitis coexisting with NMOSD. A 27-year-old male presented with blurred vision, cognitive impairment, psychosis, dysphagia, gait instability and urinary incontinence. Brain magnetic resonance imaging (MRI) showed abnormal signals in the right cerebellar hemisphere, temporal lobe, and corpus callosum. NMDAR antibodies were positive in the CSF. AQP4-IgG antibodies were positive in the serum. The patient's condition was stable following intravenous gamma globulin, corticosteroids, immunosuppressants and symptomatic treatments.

Conclusions

This case provides further evidence for the occurrence of anti-NMDAR encephalitis overlapping NMOSD with AQP4-IgG-seropositive in a Chinese patient. However, the mechanisms underlying the occurrence of double-positive antibodies remain elusive.

Case Report: Overlapping Syndrome of Anti-NMDAR Encephalitis and MOG Inflammatory Demyelinating Disease in a Patient With Human Herpesviruses 7 Infection

Objectives

This study reported a case of overlapping anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis and myelin oligodendrocyte glycoprotein (MOG) inflammatory demyelinating disease with human herpesviruses 7 (HHV-7) infection.

Methods

The detailed clinical characteristics, neuroimaging features, and outcomes of the patient were collected. Polymerase chain reaction (PCR), cell-based assay (CBA) and the tissue-based indirect immunofluorescence assay (TBA) were used for diagnosis.

Results

The clinical manifestations included headache, dizziness, fever, optic neuritis, and epileptic-seizures. Brain magnetic resonance imaging (MRI) showed hyperintensities involving the left frontal, orbital gyrus and bilateral optic nerve with substantial contrast enhancement. Moreover, test for HHV-7 DNA by using the next generation sequencing metagenomics and polymerase chain reaction showed positive result in CSF but not in the serum samples. Anti-HHV-7 IgM and IgG antibodies were detected in both the serum and cerebrospinal fluid. NMDAR antibodies (1:10) were found positive in the patient’s CSF by a cell-based assay, and MOG antibodies were positive in the serum (1:10) and CSF (1:32). The patient appeared to respond well to immune therapy and it was found that the clinical symptoms including epileptic-seizure as well as headache were relieved and cerebral lesions almost disappeared after the treatment. However, his vision was not completely restored even at the 8-month follow-up, especially the vision in his right eye which was more seriously damaged.

Discussion

We report a rare case of MOG antibodies and anti-NMDAR encephalitis overlapping syndrome (MNOS) with HHV-7 infection for the first time. The possibility of MNOS needs be considered when optic neuritis occurs in the patients diagnosed with anti-NMDAR encephalitis. Besides, immunotherapy should be initiated as early as possible to improve the treatment outcomes and facilitate complete cure.

Clinical Profile and Treatment Outcome in MOGAD: A Single-Center Case-Series Study in Guiyang, China

Background

The clinical spectrum of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is expanding over time. However, the long-term management and prognosis of this disorder are still controversial. Therefore, this study aimed to report the clinical profiles and treatment outcomes of MOGAD in our center.

Methods

This was a single-center case-series study. Clinical and para-clinical data, along with treatment outcomes of patients with MOGAD were analyzed.

Results

A total of 27 patients were identified, of which 19 (70%) patients were women, and the median age at disease onset was 40 years (range 20–67). A total of 47 episodes were observed, with optic neuritis (53%) being the most frequent presentation and 60% of them were unilateral. Other presentations included rhombencephalitis (RE) (17%), limbic encephalitis (9%), simultaneous optic neuritis and myelitis (9%), acute disseminated encephalomyelitis (ADEM)-like presentation (6%), myelitis (4%), and ADEM (2%). One patient presenting with RE also met the diagnostic criteria of area postrema syndrome (APS). Another patient with RE presented with imaging characteristics of chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS). A total of 29 lumbar punctures were recorded, among which an elevated protein level was found in 34% of the samples, pleocytosis was found in 14% of the samples, and positive intrathecal oligoclonal bands were found in 19% of the patients. One patient was found to have anti-N-methyl-D-aspartate receptor antibodies both in his serum and cerebrospinal fluid. Intravenous methylprednisolone (IVMP) was administrated for 85% of the attacks while both IVMP and intravenous immunoglobulin were for 6% of the attacks. Moreover, nine patients received maintenance therapy. Among them, six patients were treated with mycophenolate mofetil, three patients were treated with prednisone, rituximab, and teriflunomide, respectively. The median follow-up period was 20 months (range 6–127). At follow-up, twelve (44%) patients experienced a relapsing course, and the median time to the first relapse was 9.5 months (range 2–120). The median Expanded Disability Status Scale score at nadir was 3.5 (range 2–8) and was 0 (range 0–3) at the last follow-up.

Conclusion

The clinical spectrum of MOGAD is heterogenous, wherein APS and CLIPPERS-form can occur. The long-term outcome of MOGAD seems benign. Further studies are warranted to determine the risk factors of relapse and identify the optimal steroid-sparing agents.

Recurrent Optic Neuritis in Paediatric Anti-N-Methyl-D-Aspartate Receptor (Anti-NMDAR) Encephalitis: Case Report and Literature Review

Optic neuritis associated with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis poses a novel challenge and is recognised as being part of overlapping antibody-associated demyelinating syndromes. We report a case of a 10-year-old girl who first presented with anti-NMDAR encephalitis and later developed four episodes of left optic neuritis. Blurring of vision, pain on eye movement, and headache were the striking features in all episodes of optic neuritis. For each recurrent episode of optic neuritis she was treated with intravenous methylprednisolone, following which visual acuity, colour vision, and visual field improved to normal. Neuroimaging was unremarkable. Myelin oligodendrocyte glycoprotein and aquaporin-4 antibody tests were negative. She developed a relapse of anti-NMDAR encephalitis after recurrent episodes of optic neuritis despite being on azathioprine. Intravenous immunoglobulin and cycles of cyclophosphamide were started, and she has been free from optic neuritis and encephalitis for more than one year since. Optic neuritis and anti-NMDAR encephalitis are reversible with intensive immunotherapy. Early and accurate diagnosis can lead to better management of this condition.

Clinical and Radiological Characteristics of Children and Adults With First-Attack Myelin Oligodendrocyte Glycoprotein Antibody Disease and Analysis of Risk Factors for Predicting the Severity at Disease Onset in Central China

Objective

To analyze and compare different clinical, laboratory, and magnetic resonance imaging characteristics between pediatric and adult patients with first-attack myelin oligodendrocyte glycoprotein antibody disease (MOGAD) and to explore predictive factors for severity at disease onset.

Methods

Patients diagnosed with MOGAD at the First Affiliated Hospital of Zhengzhou University from January 2013 to August 2021 were enrolled in this retrospective study. Age at disease onset, sex, comorbidities, laboratory tests, magnetic resonance imaging (MRI) characteristics, and Expanded Disability Status Scale (EDSS) scores were collected and analyzed. The association between risk factors and initial EDSS scores at disease onset was analyzed using logistic regression models and Spearman correlation analyses. A receiver-operating characteristic (ROC) curve analysis was used to evaluate the predictive ability of the uric acid and homocysteine (Hcy) levels for the severity of neurological dysfunction at the onset of MOGAD.

Results

Sixty-seven patients (female, n=34; male, n=33) with first-attack MOGAD were included in this study. The mean age at onset was 26.43 ± 18.22 years (range: 3–79 years). Among patients &lt;18 years of age, the most common presenting symptoms were loss of vision (36.0%), and nausea and vomiting (24.0%), and the most common disease spectrum was acute disseminated encephalomyelitis (ADEM) (40.0%). Among patients aged ≥18 years, the most common presenting symptoms were loss of vision (35.7%), paresthesia (33.3%), and paralysis (26.2%), and the most common disease spectrum was optic neuritis (35.7%). The most common lesions were cortical gray matter/paracortical white matter lesions in both pediatric and adult patients. Uric acid [odds ratio (OR)=1.014; 95% confidence interval (CI)=1.006–1.022; P=0.000] and serum Hcy (OR=1.125; 95% CI=1.017–1.246; P=0.023) levels were significantly associated with the severity of neurological dysfunction at disease onset. Uric acid levels (r=0.2583; P=0.035) and Hcy levels (r=0.3971; P=0.0009) were positively correlated with initial EDSS scores. The areas under the ROC curve were 0.7775 (95% CI= 0.6617‒0.8933; P&lt;0.001) and 0.6767 (95% CI=0.5433‒0.8102, P=0.014) for uric acid and Hcy levels, respectively.

Conclusion

The clinical phenotype of MOGAD varies in patients of different ages. The most common disease spectrum was ADEM in patients aged&lt;18 years, while optic neuritis was commonly found in patients aged ≥18 years. The uric acid and Hcy levels are risk factors for the severity of neurological dysfunction at disease onset in patients with first-attack MOGAD.

Comparative study of AQP4 antibody-related diseases and MOG antibody-related diseases among the population in Hunan, China

To compare the clinical, imaging, and prognostic characteristics of AQP4 antibody-related diseases and MOG antibody-related diseases. The clinical data of 56 AQP4 antibody-positive patients and 14 MOG antibody-positive patients in the Second Xiangya Hospital of Central South University from June 2016 to June 2019 were collected. 92.9% of the patients with positive AQP4 antibody were females and 64.3% of patients with positive MOG antibody were females (P = 0.004). Patients with positive AQP4 antibody were more likely to have limb movement (P < 0.001) or limb sensory dysfunction (P < 0.001), and were more likely to have limb twitching (P = 0.036). In addition, AQP4 antibody-positive patients were more likely to have positive ANA (P = 0.013) and SSA antibody (P = 0.029), Ro-52 antibody (P = 0.047), immunoglobulin (P = 0.007), thyroid antibody (P = 0.007), abnormal C3 (P = 0.011), abnormal C4 (P = 0.014) than MOG antibody-positive patients. The involvement rate of head in MOG antibody-positive patients was higher than AQP4 antibody-positive patients (P = 0.029). The severity of clinical symptoms in AQP4-positive patients was usually more serious than that in MOG-positive patients (P < 0.001). The residual neurological deficit after treatment in AQP4-positive group was usually more serious than that in MOG-positive group (P < 0.001). AQP4 antibody-positive patients had a higher prevalence in women than MOG antibody-positive patients, and AQP4 antibody-positive patients were more likely to have spinal cord involvement symptoms and connective tissue antibody abnormalities. The EDSS score of them were higher than that of MOG antibody-positive patients after treatment, and the prognosis was worse.

Brainstem syndrome at onset is related to an early MS diagnosis in Peru: A national referral center cohort

Background

MS is unpredictable regarding clinical symptoms; however, certain symptoms represent the preferred localization of white matter lesions such as brainstem, spinal cord; or optic nerve.

Objectives

To investigate the epidemiological, clinical, and imaging characteristics of MS patients in a national referral center in Peru, and to evaluate whether the type of symptom at onset relates with the time to making an MS diagnosis.

Methods

Retrospective study of MS patients at the Instituto Nacional de Ciencias Neurológicas between January 2010 and December 2018. Four different syndromes were selected for analysis as symptom onset (optic neuritis, brainstem syndrome, myelitis, and others).

Results

we identified 268 patients for whom a diagnosis of MS had been given; after excluding misdiagnosed patients (33 Neuromyelitis optica), lost or incomplete records, 121 patients were included. The majority of patients (46.6%) were born in Lima. Female to male ratio was 1.37 to 1, mean age at diagnosis was 31 years. At onset, myelitis was present in 35% of RRMS patients, followed by brainstem syndrome (25%) and optic neuritis (18%). Brainstem syndrome was statistically significant predictor for earlier diagnosis (adjusted HR: 2.09; p = 0.015).

Conclusion

Brainstem syndrome as an initial presentation of MS in Peru is related to an earlier diagnosis.

∙

In Peru, the epidemiology of MS is still a major neglected topic.

∙

Brainstem syndrome as an initial presentation of MS in Peru is related to an early diagnosis.

∙

Our population represents different regions of our country.

∙

Similar clinical, epidemiological and imaging characteristic to other Latin American countries were found.

∙

We found a misdiagnosis rate of 36.2%, which remains a contemporary problem in MS diagnosis.

Clinical and Imaging Features of Patients With Encephalitic Symptoms and Myelin Oligodendrocyte Glycoprotein Antibodies

Background

Myelin oligodendrocyte glycoprotein-antibody (MOG-ab)-associated disease (MOGAD) has highly heterogenous clinical and imaging presentations, in which encephalitis is an important phenotype. In recent years, some atypical presentations in MOG-ab-associated encephalitis (MOG-E) have been increasingly reported but have not yet been described well. The aim of the study was to describe the clinical and imaging features of patients with MOG-E in our center. Atypical phenotypes would be reported, which is expected to expand the spectrum of MOGAD.

Methods

We reviewed medical records of 59 patients with MOGAD diagnosed in our center and identified cases who had ever experienced encephalitic symptoms. Three hundred ten patients with autoimmune encephalitis (AE) were also reviewed, and cases with positive MOG-ab were identified. Besides, patients with chronically progressive encephalitis were identified from 13 MOG-E and 310 AE patients. We collected demographic, clinical, laboratory, radiological, and outcome data to explore clinical and imaging characteristics in MOG-E, especially in the atypical phenotype of chronically progressive encephalitis.

Results

We identified 13 patients (7 males, 6 females) with MOG-E. The median age at onset was 33 years (range 13~62 years). Most (9/13, 69.2%) of patients showed acute or subacute onset of encephalitic symptoms. Brain MRI abnormalities were observed in all patients. The most common lesion locations on MRI were cortical/subcortical (11/13, 84.6%), deep/periventricular white matter (10/13, 76.9%) and corpus callosum (4/13, 30.8%). Brain MRI patterns were categorized into four phenotypes. The most common pattern was cortical encephalitis with leptomeningeal enhancement/brain atrophy (10/13, 76.9%). Eight (8/13, 61.5%) patients had a good response to immunotherapy. Four (4/13, 30.8%) patients with chronically progressive course were identified from MOG-E cohort. They showed leukodystrophy-like pattern, multifocal hazy lesions, or cortical encephalitis on MRI. With immunotherapy, they only showed mild or no improvement. We also identified four (4/310, 1.3%) patients with chronically progressive course from AE cohort. They had better outcomes than counterparts in MOG-E.

Conclusions

This study demonstrates that encephalitic presentations in MOGAD had complex clinical patterns. Chronically progressive encephalitis may be a new phenotype of MOGAD. We recommend to test MOG-ab in subacute and chronic progressive dementia with leukodystrophy-like MRI lesions.

Psychiatric symptoms as initial manifestation in neuromyelitis optica spectrum disorder without cortical lesions: A report of two cases

Diagnosing neuromyelitis optica spectrum disorder (NMOSD) remains a challenge, especially in patients with atypical presentations. Here, we describe two NMOSD patients who initially presented psychiatric symptoms without cortical lesions. This report expands our understanding of the possible presentations of NMOSD. Knowledge of rare initial symptoms may allow timely diagnosis and early therapeutic intervention, preventing more severe attacks affecting the spinal cord or eyes.

Clinical Features of Coexisting Anti-NMDAR and MOG Antibody-Associated Encephalitis: A Systematic Review and Meta-Analysis

Coexisting anti-NMDAR and MOG antibody (anti-NMDAR-IgG⁺/MOG-IgG⁺)-associated encephalitis have garnered great attention. This study aimed to perform a secondary analysis to determine the clinical features of this disease. We searched several databases for related publications published prior to April 2021. A pooled analysis was conducted with the fixed-effects model using the Mante-Haenszel method (I ² ≤ 50%), or the random-effects model computed by the DerSimonian-Laird method (I ² > 50%). Stata software (version 15.0 SE) was used for the analyses. Nine observational studies and 16 case reports (58 cases with anti-NMDAR-IgG⁺/MOG-IgG⁺, 21.0 [8.5, 29.0] years, male 58.6%) were included. The incidences (95%CI) of anti-NMDAR-IgG⁺/MOG-IgG⁺ in the patients with serum MOG-IgG⁺ and CSF anti-NMDAR-IgG⁺ were 0.09 (0.02-0.19) and 0.07 (0.01-0.19), respectively. The median [IQR] of CSF anti-NMDAR antibody titer was 32 [10, 100], and the serum anti-MOG antibody titer was 100 [32, 320]. The prominent clinical symptoms were encephalitic manifestations, including seizures (56.9%) and abnormal behavior (51.7%), rather than demyelinating manifestations, such as speech disorder (34.5%) and optic neuritis (27.6%). Relapse occurred in 63.4% of anti-NMDAR-IgG⁺/MOG-IgG⁺ patients, in whom 50.0% of cases relapsed with encephalitic manifestations, and 53.8% relapsed with demyelinating manifestations. The common MRI changes were in the cortex or subcortex (70.7%) and brainstem (31.0%). 31.3% of patients presented with unilateral cerebral cortical encephalitis with epilepsy and 12.5% displayed bilateral frontal cerebral cortex encephalitis. Anti-NMDAR-IgG⁺/MOG-IgG⁺ patients showed more frequent mental behavior (OR, 95%CI, 68.38, 1.36-3,434.37), involuntary movement (57.86, 2.53-1,325.11), sleep disorders (195.00, 7.07-5,380.15), and leptomeninge lesions (7.32, 1.81-29.58), and less frequent optic neuritis (0.27, 0.09-0.83) compared to anti-NMDAR-IgG^-/MOG-IgG⁺ patients and presented more common relapse (5.63, 1.75-18.09), preceding infection (2.69, 1.03-7.02), subcortical lesions (116.60, 4.89-2,782.09), basal ganglia lesions (68.14, 2.99-1,554.27), brainstem lesions (24.09, 1.01-574.81), and spinal cord lesions (24.09, 1.01-574.81) compared to anti-NMDAR-IgG⁺/MOG-IgG^-. In conclusion, anti-NMDAR-IgG⁺/MOG-IgG⁺ was rarely observed, but the incidence rate of relapse was very high. The overall symptoms seemed to be similar to those of NMDAR encephalitis.

Autoimmune neurology: Co-occurrence of anti-NMDAR encephalitis and anti-MOG associated disease, report of a case

We report the case of a patient with symptoms of anti-NMDAR encephalitis and anti-MOG associated disease simultaneously, in whom the identification of antibodies guided to a more aggressive treatment strategy, resulting in a good clinical outcome. MRI is an important tool to diagnose this kind of patients. The co-occurrence of both diseases in infrequent, but atypical symptoms should increase our awareness of the possibility of an overlap syndrome.

The occurrence of myelin oligodendrocyte glycoprotein antibodies in aquaporin-4-antibody seronegative Neuromyelitis Optica Spectrum Disorder: A systematic review and meta-analysis

BACKGROUND

Despite inclusion in neuromyelitis optica spectrum disorders (NMOSD), myelin oligodendrocyte glycoprotein antibody (MOG-Ab)-associated diseases are increasingly recognized as an independent disease entity. In this study, we conducted a systematic review and meta-analysis to comprehensively update the rate of occurrence of MOG-Ab in Aquaporin4 (AQP4)-antibody seronegative NMOSD.

METHODS

We searched PubMed, EMBASE, and Cochrane databases for studies reporting the rates of patients with MOG-Ab in NMOSD. Fixed or random-effects models were used to pool results across studies.

RESULTS

Fourteen studies met the inclusion criteria. Overall, MOG-Abs positive patients comprised 9.3% of all NMO/NMOSD (95% confidence interval [CI] 7.9%-10.8%, I² = 13.1%), 32.5% of all AQP4-Ab seronegative NMO/NMOSD (95% CI 25.7%-39.3%, I² = 45.8%), and 41.6% of AQP4-Ab seronegative NMOSD cases diagnosed by IPND 2015 criteria (95% CI 35.1%-48.2%, I² = 0.0%). The pooled prevalence of MOG-Ab was 31.0% among Asian AQP4-Ab seronegative NMO/NMOSD patients (95% CI 22.1%-39.9% I²=54.1%) and 34.3% in European seronegative NMO/NMOSD (95% CI 21.9%-46.7%, I² = 51.9%).

CONCLUSIONS

This study shows that MOG-Abs represent a substantial proportion of AQP4-Ab seronegative NMOSD patients despite different underlying mechanisms, clinical manifestations, and treatment response, suggesting MOG-Ab screening in AQP4-Ab seronegative NMOSD patients can facilitate accurate diagnoses and treatments.

Overlapping syndrome of anti-N-methyl-D-aspartate receptor encephalitis and anti-myelin oligodendrocyte glycoprotein inflammatory demyelinating diseases: A distinct clinical entity?

BACKGROUND

The co-existence of anti-N-methyl-D-aspartate receptor encephalitis (NMDARe) and anti-myelin oligodendrocyte glycoprotein (MOG) antibody disease has sparsely been reported, which needs to be investigated.

METHOD

Among the patients with NMDARe in Xuanwu Hospital, MOG antibody disease and NMDARe overlapping syndrome (MNOS) were retrospectively identified. We combined our data with those from previously reported cases to characterize this new entity.

RESULT

There were 45 patients with MNOS with a median onset age of 20. A total of 97.8% of the patients had symptoms of encephalitis; 68.9% of the patients had symptoms of demyelination, including optic neuritis (ON) (37.9%), longitudinally extensive transverse myelitis (LETM) (31.0%) and acute disseminated encephalomyelitis (ADEM) (27.6%). Abnormal signals on magnetic resonance imaging (MRI) usually involved cortical (46.7%), subcortical (31.1%) and basal ganglia (26.7%) lesions, as well as infratentorial (48.9%) and spinal cord (28.9%) lesions. No tumours were found. A total of 62.2% of the patients relapsed, with recurrence rates of 66.7% and 50.0% for those treated with first-line therapy alone and in combination with second-line immunotherapy, respectively. The pathological changes from the biopsy indicated immune-mediated inflammatory demyelination. Although some patients may have residual deficits, 93.3% of the patients became functionally independent.

CONCLUSION

The possibility of MNOS should be considered when patients diagnosed with anti-NMDARe simultaneously or sequentially develop ON, LETM or ADEM. MNOS occurred without tumour association, and inflammatory demyelination may be the pathological change. Steroids combined with second-line immunotherapy can help to reduce high recurrence rates, and most patients will have substantial recovery.

The Emerging Role of Microglia in Neuromyelitis Optica

Neuromyelitis optica (NMO) is an autoantibody-triggered neuro-inflammatory disease which preferentially attacks the spinal cord and optic nerve. Its defining autoantibody is specific for the water channel protein, aquaporin-4 (AQP4), which primarily is localized at the end-feet of astrocytes. Histopathology studies of early NMO lesions demonstrated prominent activation of microglia, the resident immune sentinels of the central nervous system (CNS). Significant microglial reactivity is also observed in NMO animal models induced by introducing AQP4-IgG into the CNS. Here we review the potential roles for microglial activation in human NMO patients as well as different animal models of NMO. We will focus primarily on the molecular mechanisms underlying microglial function and microglia-astrocyte interaction in NMO pathogenesis. Understanding the role of microglia in NMO pathology may yield novel therapeutic approaches for this disease.

Long-term Functional Outcomes and Relapse of Anti-NMDA Receptor Encephalitis: A Cohort Study in Western China

Objective

To study the factors associated with relapse and functional outcomes in patients with anti-NMDA receptor encephalitis in Western China.

Methods

The Outcome of the anti-NMDA receptor Encephalitis Study in Western China was initiated in October 2011 to collect prospective observational data from consecutively enrolled patients with anti-NMDA receptor encephalitis.

Results

We consecutively enrolled 244 patients (median age: 26 years, range: 9–78 years; females: 128 [52.45%]) between October 2011 and September 2019. Fatality occurred in 17 (6.96%) patients, and tumors were found in 38 (15.57%) patients. The median follow-up duration was 40 (6–96) months. Of these patients, 84.8% showed clinical improvements within 4 weeks after immunotherapy, with a median modified Rankin Scale of 2 (interquartile range [IQR]: 2–3), and 80.7% (median: 1, IQR: 0–2) and 85.7% (median: 0, IQR: 0–1) had substantial recovery (i.e., mild or no residual symptoms) at 12 and 24 months, respectively. The overall prognosis was still improving at 42 months after onset. Disturbance of consciousness during the first month was the only independent predictor (OR: 2.91, 95% CI: 1.27–6.65; p = 0.01) of a poor functional neurologic outcome. Overall, 15.9% of the patients had one or multiple relapses, with 82.0% experiencing the first relapse within 24 months and 76.9% experiencing relapses that were less severe than the initial episodes. Relapse-related risk factors included the female sex and delayed treatment (p < 0.05).

Conclusions

Most patients achieved favorable long-term functional outcomes. Some patients experienced one or multiple relapses, especially female patients. Timely immunotherapy at onset may reduce the risk of relapse.

Novel insights into pathophysiology and therapeutic possibilities reveal further differences between AQP4-IgG- and MOG-IgG-associated diseases

PURPOSE OF REVIEW

This review summarizes recent insights into the pathogenesis and therapeutic options for patients with MOG- or AQP4-antibodies.

RECENT FINDINGS

Although AQP4-IgG are linked to NMOSD, MOG-IgG-associated diseases (MOGAD) include a broader clinical spectrum of autoimmune diseases of the central nervous system (CNS). Details of membrane assembly of AQP4-IgG required for complement activation have been uncovered. Affinity-purified MOG-IgG from patients were shown to be pathogenic by induction of demyelination when the blood--brain barrier (BBB) was breached and by enhancement of activation of cognate T cells. A high-affinity AQP4-IgG, given peripherally, could induce NMOSD-like lesions in rats in the absence of BBB breach. Circulating AQP4-specific and MOG-specific B cells were identified and suggest differences in origin of MOG-antibodies or AQP4-antibodies. Patients with MOG-IgG show a dichotomy concerning circulating MOG-specific B cells; whether this is related to differences in clinical response of anti-CD20 therapy remains to be analyzed. Clinical trials of AQP4-IgG-positive NMOSD patients showed success with eculizumab (preventing cleavage of complement factor C5, thereby blocking formation of chemotactic C5a and membrane attack complex C9neo), inebilizumab (depleting CD19 + B cells), and satralizumab (anti-IL-6R blocking IL-6 actions).

SUMMARY

New insights into pathological mechanisms and therapeutic responses argue to consider NMOSD with AQP4-IgG and MOGAD as separate disease entities.

Myelin Oligodendrocyte Glycoprotein (MOG) Antibody Positive Patients in a Multi-Ethnic Canadian Cohort

Introduction: Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease is a recently described central nervous system (CNS) inflammatory disorder with phenotypic overlap with Neuromyelitis Optica Spectrum Disorder (NMOSD). NMOSD seronegative patients, and those with limited forms of the disorder, become suspects for MOG antibody-associated disease. We describe a multi-ethnic population with MOG antibody seropositivity from the University of British Columbia MS/NMO clinic. Methods: AQP4-antibody seronegative patients presenting 2005-2016 with CNS inflammatory disease suspicious for NMOSD, as well as 20 MS controls, were retrospectively tested for MOG-IgG1 antibodies by live cell-based assay at Oxford Autoimmune Neurology Diagnostic Laboratory (UK) and by a commercial fixed cell-based assay at MitogenDx (Calgary, Canada). Additional MOG seropositive cases were identified through routine clinical interaction (2016-2018) using one of these laboratories. Clinical data was reviewed retrospectively. Results: Retrospective testing identified 21 MOG seropositives (14 by live assay only, 3 by fixed assay only and 4 by both) representing 14% of the "NMOSD suspects" cohort. One multiple sclerosis (MS) control serum was MOG seropositive. Twenty additional MOG positive cases were identified prospectively. Of 42 patients (27 female), median disease onset age was 29 years (range 3-62; 9 pediatric cases), 20 (47%) were non-Caucasian, and 3 (7%) had comorbid autoimmune disease. Most common onset phenotypes were optic neuritis (23, 55%; 8 bilateral) and myelitis (9, 21%; 6 longitudinally extensive) Three of the patients in our cohort experienced cortical encephalitis; two presented with seizures. Onset was moderate-severe in 64%, but 74% had good response to initial steroid therapy. Cumulative relapse probability for the MOG positive group at 1 year was 0.428 and at 4 years was 0.628. Most had abnormal brain imaging, including cortical encephalitis and poorly demarcated subcortical and infratentorial lesions. Few "classic MS" lesions were seen. Optic nerve lesions (frequently bilateral) were long and predominantly anterior, but 5 extended to the chiasm. Spinal cord lesions were long and short, with involvement of multiple spinal regions simultaneously, including the conus medullaris. Conclusions: Our MOG seropositive patients display phenotypes similar to previous descriptions, including cortical lesions with seizures and conus medullaris involvement. Many patients relapsed, predominantly in a different CNS location from onset. Serologic data from two different cell-based antibody assays highlight the discrepancies between live and fixed testing for MOG antibodies.