A nation-wide survey of Japanese pediatric MOG antibody-associated diseases.

OBJECTIVE: To elucidate the clinical characteristics of Japanese pediatric patients with acquired demyelinating diseases (ADS), positive for myelin oligodendrocyte glycoprotein antibody (MOG-IgG), we conducted a nation-wide survey. METHODS: Information about pediatric patients under 18 years old with ADS was solicited with surveys sent to 323 facilities. In an initial survey, we asked whether the center had any patients with ADS, and the MOG-IgG serostatus of the patients. In a follow-up survey, we requested more precise information on patients with ADS. RESULTS: Initial survey: 263 replies providing information on 175 patients were received. MOG-IgG were examined in 78 patients and 54 of those (69%) were positive for MOG-IgG. Follow-up survey: The characteristic involvement was optic neuritis, with visual disturbance and optic pain as characteristic symptoms. The relapse rate was 44% in patients positive for MOG-IgG, which was higher than that in seronegative patients (38%). For acute phase treatments, corticosteroid (CS), plasma exchange, and intravenous immunoglobulin (IVIG) were useful. To prevent relapse, CS, intermittent IVIG, immunosuppressants, and monoclonal antibodies were useful, but the efficacies of disease modifying drugs were uncertain. Sequelae such as visual disturbance, cognitive impairment, motor dysfunction, and epilepsy were observed in 11% of patients with MOG-IgG. CONCLUSIONS: MOG antibody-associated diseases were found to be common among pediatric ADS patients. Since a variety of sequelae were observed in these patients, it is important to identify the appropriate treatment to ensure the best outcome. The presence of the MOG autoantibody should be taken into consideration as part of the diagnostic criteria for pediatric ADS.

Spectrum of anti-myelin oligodendrocyte glycoprotein antibody (MOG-Ab)-associated diseases: an Indian perspective.

Myelin oligodendrocyte glycoprotein antibody (MOG-Ab) is involved in the pathogenesis of central nervous system (CNS) demyelination disorders. We aimed to explore the spectrum of MOG-Ab-associated diseases in eastern India. A single-center, prospective observational study was done over a period of 2 years in a tertiary care hospital of eastern India. Patients with CNS demyelination disorders who tested positive for MOG-Ab using live cell-based assay were included in the study; while, those with age less than 1 year, documented preexisting CNS structural lesions, developmental delays or diagnosed multiple sclerosis were excluded. Demographic profile, clinical spectrum, disease course, radiological features as well as response to treatment were analyzed among included patients. Twenty MOG-Ab-positive patients were included (M:F 1:1.85). The median age of symptom onset was 10.5 years. The median follow-up of patients was 13 months. Acute disseminated encephalomyelitis (ADEM) was the commonest presentation at first attack (55%), followed by optic neuritis (ON) (45%). Patients with ADEM had a significantly lower age at first attack (p = 0.025). Monophasic and relapsing disease courses were seen in 45% and 55% patients, respectively. While all patients with only ADEM had a monophasic course, 77.8% with ON had a relapsing course. Among patients who presented with isolated transverse myelitis, 75% had a monophasic course and all had disease confined to the spinal cord. Good response to corticosteroids was seen in majority of participants. Second-line drugs were needed in 55% patients, rituximab being the commonest second-line agent used. 35% patients had significant disability (EDSS > 4) at last follow-up. MOG-Ab-associated diseases have diverse clinical phenotypes characterized by age-dependent pattern-specific courses.

COVID-19-Induced Acute Bilateral Optic Neuritis.

A 44-year-old male patient with no past medical history presented 2 weeks after seropositive coronavirus disease 2019 (COVID-19) infection with vision problems suggestive of optic neuritis. Radiological testing showed findings suspicious for acute bilateral optic neuritis. The patient had also anti-MOG antibodies. Whether this was an optic neuritis due to COVID-19, MOG antibody disease, or an activation of MOG antibody disease by COVID-19 is discussed in this case.

'Twenty syndrome' in neuromyelitis optica spectrum disorder.

A 30-year-old woman presented with recurrent hiccups, vomiting and painful diminution of vision and gait instability for 1 day. She had one-and-a-half syndrome, bilateral seventh cranial nerve paresis with bilateral symptomatic optic neuritis and left-sided ataxic haemiparesis. We described her disorder as the 'twenty syndrome' (11/2+7+7+2+2+½=20). MRI of her brain revealed demyelination predominantly in right posterolateral aspect of pons, medulla and bilateral optic nerves. Serum antiaquaporin-4 antibody came out positive. Thus, she was diagnosed as neuromyelitis optica spectrum disorder (NMOSD). She responded brilliantly to immunosuppressive therapy. This is the first ever reported case of the 'twenty syndrome' secondary to cerebral NMOSD.

Population-Based Incidence of Optic Neuritis in the Era of Aquaporin-4 and Myelin Oligodendrocyte Glycoprotein Antibodies.

PURPOSE: To re-evaluate the population-based incidence of optic neuritis in the era of aquaporin-4-immunoglobulin G (AQP4-IgG) and myelin oligodendrocyte glycoprotein (MOG)-IgG, which are biomarkers of optic neuritis that is distinct from multiple sclerosis (MS). Over the past 15 years, 2 new biomarkers have been discovered that allow for further characterization of the cause of atypical optic neuritis: AQP4-IgG and MOG-IgG. DESIGN: Retrospective, population-based cohort. SETTING: population-based. PARTICIPANTS: all residents of Olmsted County, Minnesota, with optic neuritis diagnosed between January 1, 2000, and December 31, 2018. METHODS: The Rochester Epidemiology Project database was used to identify patients. Sera were tested for AQP4-IgG and MOG-IgG by using a live-cell-based flow cytometry assay. Main outcome measurements were the incidence and cause of optic neuritis. RESULTS: Optic neuritis was diagnosed in 110 patients, providing an annual incidence of 3.9 per 100,000. The final diagnosis was MS in 57%, idiopathic in 29%, MOG-IgG-associated disorder in 5%, AQP4-IgG-seropositive neuromyelitis optic spectrum disorder (NMOSD) in 3%, infectious type in 2%, sarcoidosis in 2%, seronegative NMOSD in 1%, and medication-related in 1%. All 3 patients positive for AQP4-IgG had more than 1 optic neuritis attack, 2 with residual no light perception vision in at least 1 eye. Among MOG-IgG-positive patients, 4 of 6 patients had recurrent optic neuritis, and all 6 had a final visual acuity of 20/30 or better. CONCLUSIONS: At a population level, AQP4-IgG and MOG-IgG account for 9% of optic neuritis and are associated with recurrent attacks, but MOG-IgG optic neuritis has a better visual outcome than AQP4-IgG optic neuritis.

Serum neurofilament light chain and optical coherence tomography measures in MS: A longitudinal study.

OBJECTIVE: To study the association between serum neurofilament light chain (sNfL) and multiple optical coherence tomography (OCT) measures in patients with MS and healthy controls (HCs). METHODS: In this prospective study, 110 patients with MS were recruited, together with 52 age- and sex-matched HCs. Clinical evaluation and spectral domain OCT and sNfL were obtained at baseline and after 5.5 years of follow-up. Nested linear mixed models were used to assess differences between MS vs HC and associations between sNfL and OCT measures. Partial correlation coefficients are reported, and p values were adjusted for the false discovery rate. RESULTS: At baseline, peripapillary retinal nerve fiber layer thickness (pRNFLT) and macular ganglion cell and inner plexiform layer thickness (mGCIP) were significantly lower in MS than HC both in MS-associated optic neuritis (MSON) (p = 0.007, p = 0.001) and nonaffected MSON (n-MSON) eyes (p = 0.003, p = 0.018), along with total macular volume (TMV) in n-MSON eyes (p = 0.011). At follow-up, MS showed significantly lower pRNFLT, mGCIP, and TMV both in MSON and n-MSON eyes (p < 0.001) compared with HC. In MS n-MSON eyes, sNfL was significantly associated with baseline pRNFLT and mGCIP (q = 0.019). No significant associations were found in MSON eyes. CONCLUSIONS: This study confirms the ability of sNfL to detect neurodegeneration in MS and advocates for the inclusion of sNfL and OCT measures in clinical trials. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that sNfL levels were associated with MS neurodegeneration measured by OCT.

High association of MOG-IgG antibodies in children with bilateral optic neuritis.

BACKGROUND: Bilateral optic neuritis (bilON) is a rare clinical presentation often thought to be associated with relapsing disorders such as neuromyelitis optica spectrum disorders (NMOSD) or multiple sclerosis (MS). OBJECTIVE: To characterize the clinical, radiological phenotype and antibody status of children presenting with bilON. MATERIAL AND METHODS: Retrospective multicenter study on children with bilON age <18 years with a first episode aquired demyelinating syndrome (ADS), cMRI, AQP4- and serum MOG-antibody status and follow-up data were collected. RESULTS: 30 patients (f:m = 15:15, median age 8.0y) with bilON met the inclusion criteria. 22/30 (73%) were MOG-positive (median: 1:1280, range: 1:160-1:1520). No patient showed AQP4-abs. 4/30 patients (13%), all with high MOG-abs titers, had recurrent episodes. No patient developed MS. Improvement after IVMP was observed in most patients (26/30; 87%). Outcome was favorable with no sequelae in 22/30 patients. Serial MOG-abs titers tested in 15/22 patients decreased to a median of 1:160 (range: 0-1:640) over a period of 31 months (range: 2-141 months) in 14/15 (93%) patients. MR imaging showed a predominantly anterior affection of the visual system in seropositive patients with bilateral intraorbital lesions in 68% (15/22), compared to 25% in MOG-negative patients (2/8). CONCLUSION: Pediatric bilON is associated with high MOG-abs titers in combination with anterior involvement of the visual system. Despite severe loss of vision, the majority of patients shows distinct recovery after IVMP.

Clinical and immunological differences between MOG associated disease and anti AQP4 antibody-positive neuromyelitis optica spectrum disorders: Blood-brain barrier breakdown and peripheral plasmablasts.

BACKGROUND: Patients with anti-aquaporin-4 (AQP4) water channel antibody-positive neuromyelitis optica spectrum disorders (AQP4-NMOSD) and myelin oligodendrocyte glycoprotein (MOG) associated disease (MOGAD) often present with similar clinical symptoms, and some cases are hard to differentiate at the time of onset. In this study, we compared the clinical characteristics, cerebrospinal fluid (CSF) analysis parameters, and peripheral T/B lymphocyte subsets during the active and chronic phases in AQP4-NMOSD and MOGAD. METHODS: A total of 17 MOGAD cases and 24 AQP4-NMOSD cases were studied. The clinical characteristics in both groups were summarized, including disease duration, total number of attacks, lesions, prevention of relapse during remission, and CSF analysis results during the active phase. T/B lymphocyte subsets were further investigated in the active and chronic phases. RESULTS: In the comparative study on clinical symptoms, a large proportion of optic neuritis was unilateral in MOGAD. In the comparative study on CSF analysis, protein level was significantly lower in MOGAD compared with AQP4-NMOSD (p = 0.006); myelin basic protein was significantly lower in MOGAD compared with AQP4-NMOSD (p = 0.04); albumin quotient was significantly lower in MOGAD compared with AQP4-NMOSD (p = 0.02); and IgG Quotient was significantly lower in MOGAD compared with AQP4-NMOSD (p = 0.05). In the analysis of T/B lymphocyte subsets, plasmablasts of the B cell subset in the active phase were significantly lower in MOGAD (2.1 ± 2.4) compared to AQP4-NMOSD (7.8 ± 7.2) (p < 0.05). In the chronic phase, transitional B cells were significantly higher in MOGAD (2.1 ± 1.8) compared to AQP4-NMOSD (0.6 ± 0.4) (p < 0.01). CONCLUSION: Clinical characteristics of MOGAD were similar to those of AQP4-NMOSD, but increased blood brain barrier permeability was suggested to be less severe in MOGAD compared to AQP4-NMOSD from CSF analysis. Furthermore, the pathogenesis of the two diseases was clearly distinct as plasmablasts in the active phase were not elevated in MOGAD, but were increased in AQP4-NMOSD.

The clinical spectrum and incidence of anti-MOG-associated acquired demyelinating syndromes in children and adults.

OBJECTIVES: The aim of this study was to assess the Dutch nationwide incidence of myelin oligodendrocyte glycoprotein (MOG)-IgG-associated acquired demyelinating syndromes (ADS) and to describe the clinical and serological characteristics of these patients. METHODS: All serum samples for routine diagnostics from February 2014 to December 2017 were sent to the single central reference laboratory for the full-length MOG-IgG cell-based assay (CBA) in the Netherlands. Clinical data from patients known in our National ADS centre were available. RESULTS: A total of 1414 samples of 1277 patients were received; of these, 92 patients (7%) were MOG-IgG-seropositive. The mean incidence was 0.16/100,000 people, with higher seropositivity in children (0.31/100,000) than in adults (0.13/100,000). In MOG-IgG-positive patients at the National ADS centre (61/92, 66%), the most common presenting phenotype is acute disseminated encephalomyelitis (ADEM, 56%) in children and optic neuritis (ON, 44%) in adults. Relapsing disease occurred in 9/34 (26%) children and 11/27 (41%) adults during median follow-up of 27.5 months. Patients were tested MOG-IgG-positive >200 months after the initial attack, suggesting an extended time to first relapse (TTFR). Longitudinal analysis of MOG-IgG (25/61, 41%) showed that 67% of the monophasic patients remain seropositive and 60% in relapsing patients. Majority of seronegative patients had no relapses (89%). CONCLUSION: This nationwide study shows that the overall incidence of MOG-IgG-seropositive disorders is 0.16 per 100,000 people. The distribution over the clinical phenotypes differs between adults and children. Seropositivity can be maintained over years even without clinical activity, while seronegative patients generally had no relapses.

Clinical Characteristics and Treatment of MOG-IgG-Associated Optic Neuritis.

PURPOSE OF REVIEW: Antibodies against myelin oligodendrocyte glycoprotein (MOG) are associated with a unique acquired central nervous system demyelinating disease-termed MOG-IgG-associated disorder (MOGAD)-which has a variety of clinical manifestations, including optic neuritis, transverse myelitis, acute disseminating encephalomyelitis, and brainstem encephalitis. In this review, we summarize the current knowledge of the clinical characteristics, neuroimaging, treatments, and outcomes of MOGAD, with a focus on optic neuritis. RECENT FINDINGS: The recent development of a reproducible, live cell-based assay for MOG-IgG, has improved our ability to identify and study this disease. Based on contemporary studies, it has become increasingly evident that MOGAD is distinct from multiple sclerosis and aquaporin-4-positive neuromyelitis optica spectrum disorder with different clinical features and treatment outcomes. There is now sufficient evidence to separate MOGAD from other inflammatory central nervous system demyelinating disorders, which will allow focused research on understanding the pathophysiology of the disease. Prospective treatment trials are needed to determine the best course of treatment, and until then, treatment plans must be individualized to the clinical manifestations and severity of disease.

The clinical presentation and treatment of MOG antibody disease at a single academic center: A case series.

OBJECTIVES: To describe the clinical presentation of MOG antibody disease (MOG-AD) in a series of patients at a single academic center. METHODS: We performed a retrospective review of patients with MOG antibodies. RESULTS: We review the clinical presentation of 11 patients with MOG antibodies. In patients seen at Duke University Health System with MOG antibodies, the most common presentation was optic neuritis. Rituximab was the most used treatment for long-term management. CONCLUSIONS: Our case series highlights the common presentation of MOG antibody disease (MOG-AD) at a single academic medical center.

GRP 78 antibodies are associated with clinical phenotype in neuromyelitis optica.

BACKGROUND: We previously reported the association between blood-brain barrier (BBB) dysfunction and glucose-regulated protein 78 (GRP 78) autoantibodies in neuromyelitis optica (NMO). OBJECTIVE: We clarify whether the BBB-endothelial cell activation induced by immunoglobulin G (IgG) is associated with the clinical phenotype, disease activity, and markers of BBB disruption. METHODS: We purified serum IgG from 24 serum samples from patients with NMO spectrum disorder (NMOSD), who were positive for anti-AQP4 antibodies (longitudinally extensive transverse myelitis [LETM], n = 14; optic neuritis [ON], n = 6; other phenotype, n = 4) and nine healthy controls. IgG was exposed to human brain microvascular endothelial cells (TY10) and the number of nuclear NF-κB p65-positive cells, as a marker of endothelial cell activation, was analyzed using a high-content imaging system. Change in BBB permeability was also measured. The presence of GRP78 autoantibodies was detected by Western blotting. RESULTS: In the LETM group, IgG significantly induced the nuclear translocation of NF-κB p65 in comparison to the ON and healthy control groups. A significant correlation was observed between the number of NF-κB nuclear-positive cells and clinical markers of BBB disruption, including Gd enhancement in spinal MRI and the cerebrospinal fluid/serum albumin ratio. This effect was significantly reduced at the remission phase in the individual NMOSD patients. Furthermore, GRP78 antibody positivity was associated with the LETM phenotype and disease severity in NMOSD patients. CONCLUSION: Endothelial cell activation was associated with the LETM phenotype, clinical markers of BBB disruption and disease activity. These observations may explain the phenotypic differences between the NMOSD subtypes, LETM, and isolated ON.

Increased Levels of Endothelin-1 in Cerebrospinal Fluid Are a Marker of Poor Visual Recovery after Optic Neuritis in Multiple Sclerosis Patients.

BACKGROUND: Multiple sclerosis (MS), a chronic inflammatory and degenerative disease of the central nervous system, typically features immune-mediated focal demyelination and secondary axonal degeneration. Cerebral hypoperfusion of the normal-appearing white matter (NAWM) has been reported in MS patients and may be mediated by elevated levels of endothelin-1 (ET-1), a most potent vasoconstrictive peptide released from reactive astrocytes in MS focal lesions. Optic neuritis (ON) is one of the most frequent manifestations of MS and also shows peripapillary vascular hypoperfusion in combination with disc swelling. AIMS: We aimed to compare serum and cerebrospinal fluid (CSF) levels of ET-1 as a potential prognostic marker of MS-ON in two groups of patients differing for severity of MS-ON clinical presentation. MATERIALS AND METHODS: A cross-sectional study to compare serum and CSF levels of ET-1 between patients with clinically aggressive MS-ON (A-MS-ON) and nonaggressive MS-ON (NA-MS-ON) according to conventional ophthalmological criteria, including optical coherence tomography. CSF and serum concentrations of ET-1 were measured using a commercially available ELISA method. RESULTS: Sixteen patients consecutively referred to the Units of Neurology for visual disturbances attributable to MS were recruited, 11 (69%) patients with A-MS-ON and 5 (31%) with NA-MS-ON. Median CSF ET-1 levels and CSF/serum ET-1 quotient were significantly higher in patients with A-MS-ON (0.30 vs. 0.56 ng/ml) as compared to NA-MS-ON (0.16 vs. 0.16). CONCLUSIONS: Severity and failure in the recovery from ON in MS patients may depend from vascular hypoperfusion of the optic nerve induced by high intrathecally produced ET-1, a potential prognostic marker of ON recovery in MS. The detection of CSF ET-1 levels may allow identifying groups of ON patients potentially benefitting from treatment with ET-1 antagonists (e.g., bosentan).

Optical coherence tomography in myelin-oligodendrocyte-glycoprotein antibody-seropositive patients: a longitudinal study.

BACKGROUND: Serum antibodies against myelin-oligodendrocyte-glycoprotein (MOG-IgG) are detectable in a proportion of patients with acute or relapsing neuroinflammation. It is unclear, if neuro-axonal damage occurs only in an attack-dependent manner or also progressively. Therefore, this study aimed to investigate longitudinally intra-retinal layer changes in eyes without new optic neuritis (ON) in MOG-IgG-seropositive patients. METHODS: We included 38 eyes of 24 patients without ON during follow-up (F/U) [median years (IQR)] 1.9 (1.0-2.2) and 56 eyes of 28 age- and sex-matched healthy controls (HC). The patient group's eyes included 18 eyes without (EyeON-) and 20 eyes with history of ON (EyeON+). Using spectral domain optical coherence tomography (OCT), we acquired peripapillary retinal nerve fiber layer thickness (pRNFL) and volumes of combined ganglion cell and inner plexiform layer (GCIP), inner nuclear layer (INL), and macular volume (MV). High-contrast visual acuity (VA) was assessed at baseline. RESULTS: At baseline in EyeON-, pRNFL (94.3 ± 15.9 µm, p = 0.36), INL (0.26 ± 0.03 mm3, p = 0.11), and MV (2.34 ± 0.11 mm3, p = 0.29) were not reduced compared to HC; GCIP showed thinning (0.57 ± 0.07 mm3; p = 0.008), and VA was reduced (logMAR 0.05 ± 0.15 vs. - 0.09 ± 0.14, p = 0.008) in comparison to HC. Longitudinally, we observed pRNFL thinning in models including all patient eyes (annual reduction - 2.20 ± 4.29 µm vs. - 0.35 ± 1.17 µm, p = 0.009) in comparison to HC. Twelve EyeON- with other than ipsilateral ON attacks ≤ 6 months before baseline showed thicker pRNFL at baseline and more severe pRNFL thinning in comparison to 6 EyeON- without other clinical relapses. CONCLUSIONS: We observed pRNFL thinning in patients with MOG-IgG during F/U, which was not accompanied by progressive GCIP reduction. This effect could be caused by a small number of EyeON- with other than ipsilateral ON attacks within 6 months before baseline. One possible interpretation could be a reduction of the swelling, which could mean that MOG-IgG patients show immune-related swelling in the CNS also outside of an attack's target area.

Epidemiologic and Clinical Characteristics of Optic Neuritis in Japan.

PURPOSE: To elucidate the clinical and epidemiologic characteristics of optic neuritis in Japan. DESIGN: Multicenter cross-sectional, observational cohort study. PARTICIPANTS: A total of 531 cases of unilateral or bilateral noninfectious optic neuritis identified in 33 institutions nationwide in Japan. METHODS: Serum samples from patients with optic neuritis were tested for anti-aquaporin-4 antibodies (AQP4-Abs) and anti-myelin oligodendrocyte glycoprotein antibodies (MOG-Abs) using a cell-based assay and were correlated with the clinical findings. MAIN OUTCOME MEASURES: Antibody positivity, clinical and radiologic characteristics, and visual outcome. RESULTS: Among 531 cases of optic neuritis, 12% were AQP4-Ab positive, 10% were MOG-Ab positive, 77% were negative for both antibodies (double-negative), and 1 case was positive for both antibodies. Pretreatment visual acuity (VA) worsened to more than a median 1.0 logarithm of the minimum angle of resolution (logMAR) in all groups. After steroid pulse therapy (combined with plasmapheresis in 32% of patients in AQP4-Ab-positive group), median VA improved to 0.4 logMAR in the AQP4-Ab-positive group, 0 logMAR in the MOG-Ab-positive group, and 0.1 logMAR in the double-negative group. The AQP4-Ab-positive group showed a high proportion of females, exhibited diverse visual field abnormalities, and demonstrated concurrent spinal cord lesions on magnetic resonance imaging (MRI) in 22% of the patients. In the MOG-Ab-positive group, although posttreatment visual outcome was good, the rates of optic disc swelling and pain with eye movement were significantly higher than those in the AQP4-Ab-positive and double-negative groups. However, most cases showed isolated optic neuritis lesions on MRI. In the double-negative group, 4% of the patients had multiple sclerosis. Multivariate logistic regression analysis of all participants identified age and presence of antibodies (MOG-Ab and AQP4-Ab) as significant factors affecting visual outcome. CONCLUSIONS: The present large-scale cohort study revealed the clinicoepidemiologic features of noninfectious optic neuritis in Japan. Anti-aquaporin-4 antibody-positive optic neuritis has poor visual outcome. In contrast, MOG-Ab positive cases manifested severe clinical findings of optic neuritis before treatment, but few showed concurrent lesions in sites other than the optic nerve and generally showed good treatment response with favorable visual outcome. These findings indicate that autoantibody measurement is useful for prompt diagnosis and proper management of optic neuritis that tends to become refractory.

Anti-CNTN1 IgG3 induces acute conduction block and motor deficits in a passive transfer rat model.

BACKGROUND: Autoantibodies against the paranodal protein contactin-1 have recently been described in patients with severe acute-onset autoimmune neuropathies and mainly belong to the IgG4 subclass that does not activate complement. IgG3 anti-contactin-1 autoantibodies are rare, but have been detected during the acute onset of disease in some cases. There is evidence that anti-contactin-1 prevents adhesive interaction, and chronic exposure to anti-contactin-1 IgG4 leads to structural changes at the nodes accompanied by neuropathic symptoms. However, the pathomechanism of acute onset of disease and the pathogenic role of IgG3 anti-contactin-1 is largely unknown. METHODS: In the present study, we aimed to model acute autoantibody exposure by intraneural injection of IgG of patients with anti-contacin-1 autoantibodies to Lewis rats. Patient IgG obtained during acute onset of disease (IgG3 predominant) and IgG from the chronic phase of disease (IgG4 predominant) were studied in comparison. RESULTS: Conduction blocks were measured in rats injected with the "acute" IgG more often than after injection of "chronic" IgG (83.3% versus 35%) and proved to be reversible within a week after injection. Impaired nerve conduction was accompanied by motor deficits in rats after injection of the "acute" IgG but only minor structural changes of the nodes. Paranodal complement deposition was detected after injection of the "acute IgG". We did not detect any inflammatory infiltrates, arguing against an inflammatory cascade as cause of damage to the nerve. We also did not observe dispersion of paranodal proteins or sodium channels to the juxtaparanodes as seen in patients after chronic exposure to anti-contactin-1. CONCLUSIONS: Our data suggest that anti-contactin-1 IgG3 induces an acute conduction block that is most probably mediated by autoantibody binding and subsequent complement deposition and may account for acute onset of disease in these patients. This supports the notion of anti-contactin-1-associated neuropathy as a paranodopathy with the nodes of Ranvier as the site of pathogenesis.

Sequential Optic Neuritis: A Neuromyelitis Optica Spectrum Disorder.

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune relapsing demyelinating disorder which often leads to severe disability typically targeting spinal cord, optic nerves, and brainstem. Around 75% of NMOSD patients have serum immunoglobulin-G (IgG) autoantibodies to the aquaporin-4 channel (AQP4-IgG). AQP4-IgG antibodies have a central role in new diagnostic criteria of NMOSD. These antibodies have a critical role in long-term management after the first attack. The prevalence of this disorder is lower than multiple sclerosis in European countries. However, NMO makes a substantial proportion of the demyelinating diseases of the central nervous system in countries like Pakistan, where it can be mistaken for multiple sclerosis. Accurate diagnosis is essential as some of the drugs for multiple sclerosis can potentially worsen NMOSD. We present a case of sequential optic neuritis with positive aquaporin 4 antibodies. We have discussed the history, examination findings, diagnostic workups, and treatment of the patient.

Clinical characteristics and outcomes of myelin oligodendrocyte glycoprotein antibody-seropositive optic neuritis in varying age groups: A cohort study in China.

PURPOSE: To investigate the clinical characteristics and outcomes of myelin oligodendrocyte glycoprotein antibody-seropositive optic neuritis (MOG-ON) in patients with varying ages of onset in China. METHODS: Patients displaying symptoms of MOG-ON were recruited from the Neuro-ophthalmology Department in the Chinese People's Liberation Army General Hospital from January 2016 to May 2018. They were assigned to one of three subgroups based on age of onset: pediatric (<18 years), young (18-46 years), and middle-aged (>46 years) MOG-ON. RESULTS: 110 patients (188 eyes) were assessed, including 58 pediatric (52.7%), 34 young (30.9%), and 18 middle-aged (16.4%) patients. Of the pediatric patients, 93.9% had good recovery of visual acuity (≥0.5) compared with 79.7% of young patients and 66.7% of middle-aged patients (p < .001). The annual relapse rate was lower in the pediatric group than young and middle-aged groups (0.32 ±â€¯0.50 vs 0.73 ±â€¯0.87 vs 0.49 ±â€¯1.08, p = .036). Six children (10.3%) were diagnosed with acute disseminated encephalomyelitis, while seven young patients (20.6%) were diagnosed with aquaporin-4 antibody seronegative neuromyelitis optica spectrum disorder upon follow-up. The average peripapillary RNFL and macular GCIPL thicknesses were not statistically different between subgroups (p = .996, p = .608). Overall, MRIs of the optic nerve showed perineural enhancement in 52.0% of patients and longitudinal extensive involvement in 87.7%. MRIs also revealed a greater proportion of pediatric patients with intracranial optic nerve involvement than in the other two subgroups (45.4% vs. 21.2% vs. 36.7%, p = .014). CONCLUSION: Pediatric ON was the most common MOG-ON subgroup. Pediatric patients had different clinical features, including better recovery of visual acuity, lower annual relapse rate, and more intracranial optic nerve involvement than young and middle-aged patients. Additionally, age of onset may be a potential predictor for determining visual prognosis with MOG-ON.