Optic neuritis in the era of biomarkers

Single-electrode electrochemiluminescence immunosensor for multiplex detection of Aquaporin-4 antibody using metal-organic gels as coreactant

Reliable detection of Aquaporin-4 (AQP4) antibodies is crucial for diagnosing Neuromyelitis Optica spectrum disorder (NMOSD). However, cell-based assays, the most reliable approach, are limited by inadequate instruments. This study reports the use of silver metal-organic gels (Ag-MOGs) as coreactants in a single-electrode electrochemical system (SEES)-based electrochemiluminescence (ECL) immunosensor for multiplex detection of AQP4 antibodies. The immunosensor was constructed by modifying the carbon nanotube single-electrode with Ag-MOGs, incubating it with AQP4 peptides, and ultimately enabling the immobilization of AQP4 antibodies. Voltage-induced potential gradients at the electrode triggered the Ru(bpy)32+ ECL reaction, and reduced emissions caused by AQP4 antibodies were recorded using a smartphone. Under optimal conditions, the immunosensor exhibited a strong linearity (10-1000 ng/mL) with a detection limit of 2.8 ng/mL. Validation of its accuracy, precision, dilutability, and selectivity confirmed robust performance across the diverse parameters. Furthermore, it successfully detected AQP4 antibodies in serum samples from seropositive NMOSD patients. The platform's single electrode design and multiplex capability make it simple, fast and cost-effective. Enhanced accessibility and user-friendliness could position this system as a transformative tool for improving disease diagnosis and treatment, particularly in resource-limited regions.

The atypical faces of optic neuritis: neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease

PURPOSE OF REVIEW

The purpose of this article is to provide a review of neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), with a focus on what renders optic neuritis "atypical" in these two conditions. Clinical features, diagnostic criteria, and epidemiology are outlined. Acute treatments for optic neuritis, as well as immunotherapy for NMOSD and MOGAD are discussed.

RECENT FINDINGS

Updates in NMOSD and MOGAD are highlighted, with an emphasis on novel work including the new 2023 MOGAD diagnostic criteria, our evolving understanding on the epidemiology of these conditions, and recently FDA-approved NMOSD treatments. Pipeline therapies are also discussed.

SUMMARY

A thorough history and examination, supported by ancillary testing, continues to be the mainstay of optic neuritis diagnosis. Stratifying typical versus atypical optic neuritis is paramount. Within the atypical category, NMOSD and MOGAD are important considerations. Clues can point towards these diagnoses and guide steps for treatment, which is increasingly becoming targeted to individual diseases, as the pathophysiology is different for these disorders.

Biomarkers in patients with autoimmune optic neuritis not associated with multiple sclerosis: Demographic, clinical and prognostic features

BACKGROUND

The new optic neuritis (ON) classification leads to a change in how ON patients are grouped. Our aim is to appraise the clinical features and prognoses of patients with autoimmune ON not associated with MS.

METHODS

Patients referred to our neuro-ophthalmology laboratory were enrolled to this retrospective study. Patients with ON associated with MS were excluded. The remaining patients were divided into three groups: aqauaporin-4 (AQP4) antibody ON group, myelin oligodendrocyte glycoprotein (MOG) antibody ON group, and seronegative ON group. The patients were examined on admission, one month after acute treatment, and at the third-year follow-up. We compared demographic, clinical, radiologic, laboratory data, and treatment responses among these three groups.

RESULTS

The study included 92 patients. The older age of onset, bilateral simultaneous involvement of the optic nerves, severe vision loss at onset, and need for aggressive treatment were more common in the AQP-ON and the MOG-ON groups than the seronegative ON group (P = 0.01, P = 0.003, P = 0.011, P = 0.007, P < 0.001, P < 0.001, respectively). The presence of optic disc edema was a significant feature of MOG-ON as well as long-length contrast enhancement on MRI (P = 0.003, P = 0.002). Additional autoimmune antibodies and CNS lesions outside the optic nerve were the features of AQP4-ON patients (P < 0.001, P = 0.015). Generalized estimating equations analysis revealed that the presence of AQP4 antibody, increased age and recurrence were associated with visual acuity over time (P = 0.014, P = 0.002, P = 0.016, respectively).

CONCLUSION

The association of serum biomarker status with demographic, clinical features, and visual outcomes indicate the importance of biomarker detection in these patients.

Analysis of the initial orbital MRI in aquaporin-4 antibody-positive optic neuritis (AQP4-ON): lesion location and lesion length can be predictive of visual prognosis

PURPOSE

Despite mounting evidence indicating that aquaporin-4 antibody-positive optic neuritis (AQP4-ON) presents a less favorable prognosis than other types of optic neuritis, there exists substantial heterogeneity in the prognostic outcomes within the AQP4-ON cohort. Considering the persistent debate over the role of MRI in assessing the prognosis of optic neuritis, we aim to investigate the correlation between the MRI appearance and long-term visual prognosis in AQP4-ON patients.

METHODS

We retrospectively reviewed the ophthalmological and imaging data of AQP4-ON patients admitted to our Neuro-ophthalmology Department from January 2015 to March 2018, with consecutive follow-up visits for a minimum of 3 years.

RESULTS

A total of 51 AQP4-ON patients (59 eyes) meeting the criteria were enrolled in this research. After assessing the initial orbital MR images of each patient at the first onset, we observed the involvement of the canalicular segment (p < 0.001), intracranial segment (p = 0.004), optic chiasm (p = 0.009), and the presence of LEON (p = 0.002) were significantly different between recovery group and impairment group. For quantitative measurement, the length of the lesions is significantly higher in the impairment group (20.1 ± 9.3 mm) than in the recovery group (12.5 ± 5.3 mm) (p = 0.001).

CONCLUSION

AQP4-ON patients with involvement of canalicular, intracranial segment and optic chiasm of the optic nerve, and the longer range of lesions threaten worse vision prognoses. Timely MR examination during the initial acute phase can not only exclude the intracranial or orbital mass lesions but also indicate visual prognosis in the long term.

A Comparative Review of Typical and Atypical Optic Neuritis: Advancements in Treatments, Diagnostics, and Prognosis

Optic neuritis (ON) is a debilitating condition that through various mechanisms, including inflammation or demyelination of the optic nerve, can result in partial or total permanent vision loss if left untreated. Accurate diagnosis and promptly initiated treatment are imperative related to the potential of permanent loss of vision if left untreated, which can lead to a significant reduction in the quality of life in affected patients. ON is subtyped as "typical" or "atypical" based on underlying causative etiology. The etiology of ON can be differentiated when appropriate diagnostic testing is performed. Using history taking, neuroimaging, and visual testing to localize the underlying pathology of ON in a time-sensitive manner is critical in mitigating these unsatisfactory outcomes. Herein, we examine the differences in presentation, pathophysiology, and treatments of typical ON causes, like multiple sclerosis (MS), and atypical causes such as neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein (MOG)-immunoglobulin G (IgG) ON. The present investigation places focus on both neuroimaging and visual imaging in the differentiation of ON. Additionally, this review presents physicians with a better understanding of different presentations, treatments, and prognoses of ON.

An update on optic neuritis

Optic neuritis (ON) is the most common cause of subacute optic neuropathy in young adults. Although most cases of optic neuritis (ON) are classified as typical, meaning idiopathic or associated with multiple sclerosis, there is a growing understanding of atypical forms of optic neuritis such as antibody mediated aquaporin-4 (AQP4)-IgG neuromyelitis optica spectrum disorder (NMOSD) and the recently described entity, myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD). Differentiating typical ON from atypical ON is important because they have different prognoses and treatments. Findings of atypical ON, including severe vision loss with poor recovery with steroids or steroid dependence, prominent optic disc edema, bilateral vision loss, and childhood or late adult onset, should prompt serologic testing for AQP4-IgG and MOG-IgG. Although the traditional division of typical and atypical ON can be helpful, it should be noted that there can be severe presentations of otherwise typical ON and mild presentations of atypical ON that blur these traditional lines. Rare causes of autoimmune optic neuropathies, such as glial fibrillary acidic protein (GFAP) and collapsin response-mediator protein 5 (CRMP5) autoimmunity also should be considered in patients with bilateral painless optic neuropathy associated with optic disc edema, especially if there are other accompanying suggestive neurologic symptoms/signs. Typical ON usually recovers well without treatment, though recovery may be expedited by steroids. Atypical ON is usually treated with intravenous steroids, and some forms, such as NMOSD, often require plasma exchange for acute attacks and long-term immunosuppressive therapy to prevent relapses. Since treatment is tailored to the cause of the ON, elucidating the etiology of the ON is of the utmost importance.

MOG-IgG positive optic neuritis after SARS-CoV-2 infection

BACKGROUND

Many neurologic complications have been described after severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) including atypical cases of optic neuritis (ON), positive to myelin oligodendrocyte glycoprotein (MOG) IgG.

OBJECTIVE

To report a case of MOG-IgG-associated ON and discuss why SARS-CoV-2 infection could be a potential trigger.

METHODS

Retrospective single case report.

RESULTS

We report a case of ON with positive MOG-IgG developed 15 days after presentation of SARS-CoV-2 infection.

CONCLUSION

This report suggests that SARS-CoV-2 infection may have triggered autoantibodies production against MOG leading to ON.

Genome-Wide Expression Profile in People with Optic Neuritis Associated with Multiple Sclerosis

The aim of this study was to perform a genome-wide expression analysis of whole-blood samples from people with optic neuritis (ON) and to determine differentially expressed mRNAs compared to healthy control subjects. The study included eight people with acute ON and six healthy control subjects. Gene expression was analyzed using DNA microarrays for whole-human-genome analysis, which contain 54,675 25-base pairs. The additional biostatistical analysis included gene ontology analysis and gene set enrichment analysis (GSEA). Quantitative RT-PCR (qPCR) was used to confirm selected differentially expressed genes. In total, 722 differently expressed genes were identified, with 377 exhibiting increased, and 345 decreased, expression. Gene ontology analysis and GSEA revealed that protein phosphorylation and intracellular compartment, apoptosis inhibition, pathways involved in cell cycles, T and B cell functions, and anti-inflammatory central nervous system (CNS) pathways are implicated in ON pathology. qPCR confirmed the differential expression of eight selected genes, with SLPI, CR3, and ITGA4 exhibiting statistically significant results. In conclusion, whole-blood gene expression analysis showed significant differences in the expression profiles of people with ON compared to healthy control subjects. Additionally, pathways involved in T cell regulation and anti-inflammatory pathways within CNS were identified as important in the early phases of MS.

Visual Outcomes Following Plasma Exchange for Optic Neuritis: An International Multicenter Retrospective Analysis of 395 Optic Neuritis Attacks

PURPOSE

To evaluate the effectiveness of plasma exchange (PLEX) for optic neuritis (ON).

METHODS

We conducted an international multicenter retrospective study evaluating the outcomes of ON following PLEX. Outcomes were compared to raw data from the Optic Neuritis Treatment Trial (ONTT) using a matched subset.

RESULTS

A total of 395 ON attack treated with PLEX from 317 patients were evaluated. The median age was 37 years (range 9-75), and 71% were female. Causes of ON included multiple sclerosis (108), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) (92), aquaporin-4-IgG-positive neuromyelitis optica spectrum disorder (AQP4+NMOSD) (75), seronegative-NMOSD (34), idiopathic (83), and other (3). Median time from onset of vision loss to PLEX was 2.6 weeks (interquartile range [IQR], 1.4-4.0). Median visual acuity (VA) at the time of PLEX was count fingers (IQR, 20/200-hand motion), and median final VA was 20/25 (IQR, 20/20-20/60) with no differences among etiologies except MOGAD-ON, which had better outcomes. In 81 (20.5%) ON attacks, the final VA was 20/200 or worse. Patients with poor outcomes were older (P = .002), had worse VA at the time of PLEX (P < .001), and longer delay to PLEX (P < .001). In comparison with the ONTT subset with severe corticosteroid-unresponsive ON, a final VA of worse than 20/40 occurred in 6 of 50 (12%) PLEX-treated ON vs 7 of 19 (37%) from the ONTT treated with intravenous methylprednisolone without PLEX (P = .04).

CONCLUSION

Most ON attacks improved with PLEX, and outcomes were better than attacks with similar severity in the ONTT. The presence of severe vision loss at nadir, older age, and longer delay to PLEX predicted a worse outcome whereas MOGAD-ON had a more favorable prognosis. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Collapsin response mediator protein 5-associated optic neuropathy: clinical characteristics, radiologic clues, and outcomes

OBJECTIVE

Collapsin response mediator protein 5-associated optic neuropathy (CRMP5-ON) is a rare entity of autoimmune optic neuropathy. This study aimed to review the neuro-ophthalmic findings and outcomes in a series of patients with CRMP5-ON to further characterize its clinical phenotype, radiologic clues, and outcomes.

METHODS

This was a retrospective case series and a single-center medical chart review of all patients with CRPM5-seropositive ON at the Department of Neurology, Beijing Tongren Hospital, from December 1, 2020, to March 31, 2023. The main outcome measures were neuro-ophthalmic manifestations, radiologic characteristics, and clinical outcomes of CRMP5-ON; coexisting neural autoantibody, paraneoplastic associations, and the impact of immunosuppressant therapy.

RESULTS

Five patients were identified. Four (80%) were female, and the average age at onset was 59.4 years (range 53-69 years), with an average follow-up of 15.3 months (range 1.4-28.7 months). The average best-corrected visual acuity (BCVA) at nadir was 20/120 (range 20/20 to count fingers). Seven of ten affected eyes (70%) showed diffuse defects of the central field. Painless bilateral involvement and optic disk edema occurred in 100% of patients, combined with vitritis, uveitis, or retinitis in four (80%). Four patients (80%) had MRI abnormalities along the optic nerve (one patient with optic nerve enhancement and three patients had optic nerve sheath enhancement or peribulbar fat enhancement). Three patients (60%) had optic neuropathy with other neurologic symptoms. Four patients (80%) had confirmed cancer (two were small-cell lung carcinoma, one was papillary thyroid carcinoma and another was thymoma and invasive pulmonary adenocarcinoma). All cancers were identified after the presentation of the optic neuropathy. The intervention included IVIG, IVMP, surgery and chemotherapy. The average BCVA at the last follow-up was 20/50 (range 20/20 to count fingers). Three patients had surgery during the initial hospitalization, and were stable during the follow-up. Among two patients who received IVMP, both had improvement after treatment, although one patient had worsening non-ocular neurologic symptoms during the steroid taper.

CONCLUSION

CRMP5-ON presented with optic disc edema, often bilateral involved and combined with vitreitis, retinitis, or uveitis. CRMP5-ON can present with MRI optic nerve or perineural optic nerve enhancement, especially in the optic nerve sheath. CRMP5-ON is closely related to paraneoplastic neurologic syndrome. Cancer screening and intervention are crucial to prognosis.

MRI pattern in acute optic neuritis: Comparing multiple sclerosis, NMO and MOGAD

BACKGROUND

Several MRI findings of optic neuritis (ON) have been described and correlated with specific underlying etiologies. Specifically, optic nerve enhancement is considered an accurate biomarker of acute ON.

OBJECTIVE

To identify differences in MRI patterns of optic nerve enhancement in certain demyelinating etiologies presenting with acute ON.

METHODS

Retrospective analysis of enhancement patterns on fat-suppressed T1-weighted images from patients presenting clinical and radiological acute ON, treated at our institution between January 2014 and June 2022. Location and extension of enhancing optic nerve segments, as well as presence of perineural enhancement were evaluated in three predetermined demyelinating conditions. Fisher's exact test and chi2 were calculated.

RESULTS

Fifty-six subjects met eligibility criteria. Mean age was 31 years (range 6-79) and 70% were females. Thirty-four (61%) patients were diagnosed with multiple sclerosis (MS), 8 (14%) with neuromyelitis optica (NMO), and 14 (25%) with anti-myelin oligodendrocyte glycoprotein disease (MOGAD). Bilateral involvement was more frequent in MOGAD, compared to MS and NMO (43 vs 3% and 12.5% respectively, p = 0.002). MS patients showed shorter optic nerve involvement, whereas MOGAD showed more extensive lesions (p = 0.006). Site of involvement was intraorbital in 63% MS, 89% NMO, 90% MOGAD (p = 0.051) and canalicular in 43% MS, 33% NMO and 75% MOGAD (p = 0.039). Intracranial or chiasmatic involvement and presence of perineural enhancement were not statistically different between entities.

CONCLUSION

In the setting of acute ON, patients presenting MOGAD were more likely to show bilateral, longitudinally extended and anterior (intraorbital and canalicular) optic nerve involvement compared to patients with MS or NMO.

The case report of AQP4 and MOG IgG double positive NMOSD treated with subcutaneous Ofatumumab

Neuromyelitis optica spectrum disorders (NMOSD) is an autoimmune demyelinating disease with IgG against aquaporin 4 (AQP4) in more than two thirds of patients. Anti-myelin-oligodendrocyte glycoprotein (MOG) antibody is found in some AQP4-negative NMOSD patients and MOG antibody-associated disease (MOGAD) is thought to be distinct from NMOSD. Due to the high disabling nature of NMOSD, treatment strategy on first attack is crucial for good prognosis. Rituximab (RTX), an anti-CD20 monoclonal antibody (mAb), is the first-line treatment for NMOSD. However, RTX can be limited by the relatively high rate of systemic allergic reaction. Herein, we reported a rare case of AQP4 and MOG-IgG double positive NMOSD patient effectively and safely treated with ofatumumab (OFA), a novel fully humanized anti-CD20 mAb.

[Neurological involvement of sarcoidosis: current diagnostic and therapeutic strategies]

Neurosarcoidosis (NS) is a rare but severe form of sarcoidosis. NS is associated with significant morbidity and mortality. Mortality is about 10% at 10 years with more than 30% of patients who have a significant disability. The most frequent features are cranial neuropathy (the facial and optic nerve most commonly affected), cranial parenchymal lesions, meningitis, spinal corn abnormalities (20-30%) and more rarely peripheral neuropathy (approximately 10-15%). The challenge of diagnosis is to eliminate other diagnoses. Atypical presentations should make to discuss the need for cerebral biopsy in order to highlight the presence of granulomatous lesions while eliminating alternative diagnosis. Therapeutic management is based on corticosteroid therapy and immunomodulators. There are no comparative prospective study to allow us to define the first-line immunosuppressive treatment and the therapeutic strategy in refractory patients. Conventional immunosuppressants such as methotrexate, mycophenolate mofetil and cyclophosphamide are commonly used. Data on the efficacy of anti-TNFα (including infliximab) in refractory and/or severe forms are increasing during the last ten years. Additional data is necessary to assess their interest in first line in patients with severe involvement and a significant risk of relapse.

The Importance of Optical Coherence Tomography in the Diagnosis of Atypical or Subclinical Optic Neuritis: A Case Series Study

Background: Optic neuritis (ON) is an inflammatory condition of the optic nerve. ON is associated with development of demyelinating diseases of the central nervous system (CNS). CNS lesions visualized by magnetic resonance imaging (MRI) and the finding of oligoclonal IgG bands (OB) in the cerebrospinal fluid (CSF) are used to stratify the risk of MS after a "first" episode of ON. However, the diagnosis of ON in absence of typical clinical manifestations can be challenging. Methods and Materials: Here we present three cases with changes in the optic nerve and ganglion cell layer in the retina over the disease course. (1) A 34-year-old female with a history of migraine and hypertension had suspect amaurosis fugax (transient vision loss) in the right eye. This patient developed MS four years later. Optical coherence tomography (OCT) showed dynamic changes of the thickness of peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GCIPL) over time. (2) A 29-year-old male with spastic hemiparesis and lesions in the spinal cord and brainstem. Six years later he showed bilateral subclinical ON identified using OCT, visual evoked potentials (VEP) and MRI. The patient fulfilled diagnosis criteria of seronegative neuromyelitis optica (NMO). (3) A 23-year-old female with overweight and headache had bilateral optic disc swelling. With OCT and lumbar puncture, idiopathic intracranial hypertension (IIH) was excluded. Further investigation showed positive antibody for myelin oligodendrocyte glycoprotein (MOG). Conclusions: These three cases illustrate the importance of using OCT to facilitate quick, objective and accurate diagnosis of atypical or subclinical ON, and thus proper therapy.

[Clinical phenotypes of optic nerve damage in patients with neuromyelitis optica spectrum disorder]

Neuromyelitis optica spectrum disorders (NMOSD) comprise a group of autoimmune inflammatory demyelinating diseases of the central nervous system that manifest as optic neuritis and transverse myelitis. Its manifestation in the form of optic neuritis makes early diagnosis difficult because neuroimaging of the spinal cord is not a part of the routine examination algorithm for such patients. This article presents the results of a comprehensive ophthalmological examination of 4 patients (8 eyes) diagnosed with NMSOD. Optic neuritis was the disease debut in 3 patients and had 1-2 relapses, in all cases partial optic atrophy with moderate to severe loss of visual function occurred. The clinical picture was characterized by a pronounced heterogeneity in terms of both ophthalmological symptoms, and accession of neurological disorders. Treatment of NMOSD requires differential diagnosis with multiple sclerosis, which depends on the awareness of specialists and the inclusion of antibody titers to aquaporin-4 and myelin oligodendrocyte glycoprotein into the examination algorithm of patients with optical neuritis.

Identification of double-stranded DNA in the cerebrospinal fluid of patients with acute neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease of the central nervous system (CNS) characterized by severe myelitis and optic neuritis. Double-stranded DNA (dsDNA) is involved in the pathogenesis of various autoimmune diseases, such as systemic lupus erythematosus. However, its role in NMOSD remains unclear. In this study, the concentration of dsDNA in the cerebrospinal fluid (CSF) was quantified in 23 patients with NMOSD and 16 patients with other neurological diseases (ONDs). CSF dsDNA levels in patients with NMOSD (median: 0.03 ng/µL) were significantly higher than those in patients with ONDs (median: 0.01 ng/μl). CSF dsDNA levels showed no significant difference before and after treatment. Elevation of CSF dsDNA levels may suggest its essential role in the augmentation of CNS inflammation in patients with NMOSD.

Details and outcomes of a large cohort of MOG-IgG associated optic neuritis

BACKGROUND

The goal of this study was to examine the temporal relationship of eye pain to visual loss and investigate whether timing of steroid treatment affects the rate and extent of visual recovery in optic neuritis (ON) from MOG-IgG associated disease (MOGAD) in a large cohort of MOGAD patients with ON.

METHODS

This is a multicenter, retrospective cohort study of consecutive MOGAD patients with ON attacks seen from 2017 to 2021 fulfilling the following criteria: (1) clinical history of ON; (2) MOG-IgG seropositivity. ON attacks were evaluated for presence/duration of eye pain, nadir of vision loss, time to intravenous methylprednisolone (IVMP) treatment, time to recovery, and final visual outcomes.

RESULTS

There were 107 patients with 140 attacks treated with IVMP and details on timing of treatment and outcomes. Eye pain was present in 125/140 (89%) attacks with pain onset a median of 3 days (range, 0 to 20) prior to vision loss. Among 46 ON attacks treated with IVMP within 2 days of onset of vision loss, median time to recovery was 4 days (range, 0 to 103) compared to 15 days (range, 0 to 365) in 94 ON attacks treated after 2 days (p = 0.004). Those treated within 2 days had less severe VA loss at time of treatment (median LogMAR VA 0.48, range, 0.1 to 3) compared to those treated after 2 days (median LogMAR VA 1.7, range, 0 to 3; p < 0.001), and were more likely to have a VA outcome of 20/40 or better (98% vs 83%, p = 0.01). After adjustment for the initial VA at time of treatment, the differences in final VA were no longer significantly different (p = 0.14). In addition, some patients were documented to recover without steroid treatment.

CONCLUSION

This study suggests that pain precedes vision loss in the majority of ON attacks and early steroids may lead to better outcomes in MOG-IgG ON, but some patients can recover without steroid treatment. Prospective randomized clinical trials are required to confirm these findings.

Should Aquaporin-4 Antibody Test Be Performed in all Patients With Isolated Optic Neuritis?

BACKGROUND

Optic neuritis (ON) may be the initial manifestation of neuromyelitis optica spectrum disorder (NMOSD). Aquaporin-4 antibody (AQP4 Ab) is used to diagnose NMOSD. This has implications on prognosis and is important for optimal management. We aim to evaluate if clinical features can distinguish AQP4 Ab seropositive and seronegative ON patients.

METHODS

We reviewed patients with first episode of isolated ON from Tan Tock Seng Hospital and Singapore National Eye Centre who tested for AQP4 Ab from 2008 to 2017. Demographic and clinical data were compared between seropositive and seronegative patients.

RESULTS

Among 106 patients (120 eyes) with first episode of isolated ON, 23 (26 eyes; 22%) were AQP4 Ab positive and 83 (94 eyes; 78%) were AQP4 Ab negative. At presentation, AQP4 Ab positive patients had older mean onset age (47.9 ± 13.6 vs 36.8 ± 12.6 years, P < 0.001), worse nadir VA (OR 1.714; 95% CI, 1.36 to 2.16; P < 0.001), less optic disc swelling (OR 5.04; 95% CI, 1.682 to 15.073; p = 0.004), and higher proportions of concomitant anti-Ro antibody (17% vs 4%, p = 0.038) and anti-La antibody (17% vs 1%, p = 0.008). More AQP4 Ab positive patients received steroid-sparing immunosuppressants (74% vs 19%, p < 0.001) and plasma exchange (13% vs 0%, p = 0.009). AQP4 Ab positive patients had worse mean logMAR VA (visual acuity) at 12 months (0.70 ± 0.3 vs 0.29 ± 0.5, p = 0.051) and 36 months (0.37±0.4 vs 0.14 ± 0.2, p = 0.048) follow-up.

CONCLUSION

Other than older onset age and retrobulbar optic neuritis, clinical features are non-discriminatory for NMOSD. We propose a low threshold for AQP4 Ab serology testing in inflammatory ON patients, particularly in high NMOSD prevalence populations, to minimize diagnostic and treatment delays.

Bilateral Optic Neuritis after COVID-19 Vaccination: A Case Report

BACKGROUND

Neuro-ophthalmic manifestations after vaccines are rare, with optic neuritis (ON) being the most common presentation. Patients with vaccine-related ON are similar to those with idiopathic ON. The temporal relationship between vaccination against and the occurrence of ON is vital. Here, we report a case of bilateral ON after the administration of the ChAdOx1-S nCoV-19 SARS-CoV-2 vaccine.

CASE

A 49-year-old healthy Asian female presented with sudden onset of bilateral blurred vision within 2 days. She complained of photophobia and extraocular pain upon movement over 3 days. Upon examination, her best corrected visual acuity (BCVA) was 20/30 in the right eye and 20/200 in the left eye. Anterior segment findings were unremarkable, with normal intraocular pressure. Fundoscopic examination revealed bilateral disc edema with vessel engorgement. Visual field examination revealed profound visual field defect in both eyes. She denied any trauma, use of new medication or medical history. She had received the ChAdOx1 nCoV-19 SARS-CoV-2 vaccine 14 days prior. Under suspicion of vaccine-related optic neuritis, she was given intravenous methylprednisolone 1 gm/day for 3 days, shifting to oral prednisolone under gradual tapering for 2 weeks.

CONCLUSIONS

Typically presenting with sudden-onset visual decline and extraocular pain during movement, acute ON is generally idiopathic. Bilateral ON is rare, but quick identification is important because it can potentially lead to permanent loss of vision if left untreated. Vaccination-induced ON is even rarer but not difficult to treat. However, such patients require further evaluation and long-term follow-up because they may be prone to other neurological disorders in the future.

Shot in the Dark

A 43-year-old woman presented with decreased vision in the right eye associated with painful eye movements 10 days after receiving her first dose of Pfizer-BioNTech coronavirus disease 2019 (COVID-19) vaccine (Pfizer Inc, New York, NY). Two days later she developed painful loss of vision in the left eye. Clinical presentation and magnetic resonance imaging findings were consistent with bilateral optic perineuritis transitioning to optic neuritis. Extensive evaluation including aquaporin-4 immunoglobin G (IgG), myelin oligodendrocyte glycoprotein IgG, and lumbar puncture was unrevealing. Visual acuity at nadir was counting fingers in both eyes, but after receiving intravenous steroids and plasma exchange vision eventually improved to 20/20 in each eye, although she was left with inferior visual field defects and bilateral optic disc pallor. This case highlights the diagnostic challenge in the evaluation of atypical optic neuritis with a review of post-COVID-19 vaccination-associated optic neuritis.

Application of the International Interocular Difference Thresholds into Practice: Localising the Patient Experience

Demyelinating diseases of the central nervous system (CNS) often have neuro-ophthalmological manifestations, and retinal examination can be helpful in making the diagnosis. The latest iteration of optical coherence tomography (OCT)-based criteria for optic neuritis in multiple sclerosis has been developed in the research realm, but its application to clinical practice, and to the more uncommon demyelinating diseases requires further study. The ability to use OCT data to distinguish between various CNS demyelinating disorders could provide additional paraclinical tools to accurately diagnose patients. Furthermore, neuro-ophthalmological testing can define the extent of inflammatory damage in the CNS, independent of patient-reported history. New referrals for OCT at a tertiary multiple sclerosis and neuro-immunology referral centre (n = 167) were analysed retrospectively for the self-reporting of optic neuritis, serological test results, and diagnosis. Only approximately 30% of patients with a clinical history of unilateral optic neuritis solely had a unilateral optic neuropathy, nearly 40% of those subjects actually having evidence of bilateral optic neuropathies. Roughly 30% of patients reporting a history of bilateral optic neuritis did not have any evidence of structural disease, with 20% of these patients having a separate, intervenable diagnosis noted on macular scans. OCT is a useful adjunct diagnostic tool in the evaluation of demyelinating disease and has the ability to aid in a more accurate diagnosis for patients. Application of the international interocular difference thresholds to a clinical patient population generally reproduces the original results, emphasising their appropriateness. The analysis distinguishing the demyelinating diseases needs to be replicated in a blinded, multi-centre setting.

Update on glial antibody-mediated optic neuritis

Optic neuritis (ON) refers to inflammatory demyelinating lesions of the optic nerve, which can cause acute or subacute vision loss and is a major cause of vision loss in young adults. Much of our understanding of typical ON is from the Optic Neuritis Treatment Trial. Glial autoantibodies to aquaporin-4 immunoglobulin (AQP4-IgG) and myelin oligodendrocyte glycoprotein immunoglobulin (MOG-IgG) are recently established biomarkers of ON that have revolutionized our understanding of atypical ON. The detection of glial antibodies is helpful in the diagnosis, treatment, and follow-up of patients with different types of ON. AQP4-IgG and MOG-IgG screening is strongly recommended for patients with atypical ON. Research on the pathogenesis of NMOSD and MOGAD will promote the development and marketing of targeted immunotherapies. The application of new and efficient drugs, such as the selective complement C5 inhibitor, IL-6 receptor inhibitor, B cell-depleting agents, and drugs against other monoclonal antibodies, provides additional medical evidence. This review provides information on the diagnosis and management of glial antibody-mediated ON.

Neuritis óptica pediátrica: un desafio diagnóstico

Introducción: la neuritis óptica requiere un diagnóstico y manejo desafiante, se puede presentar de forma aislada o asociada con trastornos inflamatorios, siendo hasta 25% de la clínica de los síndromes desmielinizantes agudos pediátricos. La incidencia anual estimada de neuritis óptica pediátrica es 0.2 por 100.000 niños, con una preponderancia femenina y una edad media de presentación de 9 a 11 años. Presentación del caso: paciente de 12 años con cuadro agudo de diplopía, dolor ocular izquierdo sin antecedentes relevantes, en quien se encontró parálisis del VI par izquierdo y resonancia magnética cerebral (RMc) con realce en nervio óptico, iniciándose tratamiento con corticoterapia endovenosa, previo descarte de patologías infecciosas, con evolución satisfactoria. Conclusiones: en el espectro de la neuritis óptica es importante el conocimiento de sus diferentes etiologías, debido a que el tratamiento y pronóstico dependen de la causa.

Anti-aquaporin-4 immunoglobulin G colorimetric detection by silver nanoparticles

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory and autoimmune disease whose biomarker is the anti-AQP4-IgG autoantibody that binds to aquaporin-4 (AQP4) protein. We introduced a nanosensor with a sensitivity of 84.6%, higher than the CBA's 76.5%. Using silver nanoparticles (AgNPs), we detected not only seropositive but also some false-negative patients previously classified with CBA. It consisted of AgNPs coated with one of a panel of 5 AQP4 epitopes. The ability in detecting the anti-AQP4-IgG in NMOSD patients depended on the epitope and synergy could be obtained by combining different epitopes. We demonstrated that NMOSD patients could easily be distinguished from healthy subjects and patients with multiple sclerosis. Using the most sensitive AQP4_61-70 peptide, we established a calibration curve to estimate the concentration of anti-AQP4-IgG in seropositive NMOSD patients. The ability to enhance the accuracy of the diagnosis may improve the prognosis of 10-27% of anti-AQP4-IgG seronegative patients worldwide.

Long-Term Visual Prognosis in Patients With Aquaporin-4-Immunoglobulin G-Positive Neuromyelitis Optica Spectrum Disorder

BACKGROUND

To identify the factors associated with visual prognosis for functional and structural outcomes of optic neuritis (ON) in patients with aquaporin-4-immunoglobulin (AQP4-IgG)-positive neuromyelitis optica spectrum disorder (NMOSD).

METHODS

We included the eyes that experienced at least 1 episode of ON and were followed for at least 2 years after the first attack of ON in patients with AQP4-IgG-positive NMOSD. We performed a retrospective review of clinical data, including ophthalmological examination and orbital MRI, of 34 eyes of 22 patients. Functional outcomes were measured as final visual acuity, visual field index, and mean deviation and structural outcomes as final retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) thickness.

RESULTS

The mean age at onset of the first ON was 42.7 ± 13.7, and all patients were female. The poor visual acuity was significantly associated with the worse final visual acuity and thinner RNFL and GCIPL. Older age also showed a negative correlation with RNFL thickness. The number of attacks was not statistically significant for functional and structural outcomes. The lesion involving the intracanalicular optic nerve to the chiasm on orbital MRI showed worse visual acuity and a thinner GCIPL. Rapid high-dose intravenous methylprednisolone pulse therapy within 3 days was statistically significant, with better visual acuity and more preserved GCIPL thickness.

CONCLUSIONS

Our results indicate that the severity of ON rather than the number of recurrences might be critical for the visual prognosis of patients with AQP4-IgG-positive NMOSD. Rapid treatment within 3 days may improve visual outcomes, and a younger age at onset may have better visual outcomes.

Comparison of 1.5 Tesla and 3.0 Tesla Magnetic Resonance Imaging in the Evaluation of Acute Demyelinating Optic Neuritis

BACKGROUND

Optic neuritis (ON) is the most common optic neuropathy in young adults. MRI is reported to have a high sensitivity for ON. Higher signal strengths of MRI may enhance resolution and lead to better detection of ON. We sought to compare the sensitivity of 3.0 Tesla (T) MRI to that of 1.5 T MRI in detecting acute demyelinating ON.

METHODS

A retrospective chart review was performed on patients with a clinical diagnosis of optic neuritis at Mayo Clinic Health System from January 2010 to April 2020. Among 1,850 patients identified, 126 patients met the eligibility criteria. Exclusion criteria comprised questionable or alternative diagnosis, diagnosis of ON before the study period, eye examinations performed elsewhere, or absence of fat-saturated head and orbits MRIs performed locally within 30 days of symptom onset. Gadolinium contrast enhancement, T2 hyperintensity, and the radiologic diagnosis of ON were recorded by a neuro-radiologist who was masked to the clinical history and the magnet strength of the MRI.

RESULTS

Fifty-three patients (42.1%) had 3.0 T MRI, and 73 patients (57.9%) had 1.5 T MRI. Overall, 88.9% (112/126) of patients were determined to have a positive MRI for ON. The radiographic sensitivity for ON was higher in the 3.0 T group compared with the 1.5 T group (98.1% vs 82.2%, respectively [P = 0.004]). The frequency of gadolinium enhancement was found to be greater in the 3 T group compared with the 1.5 T group (98.1% vs 76.7%, respectively [P < 0.001]). T2 hyperintensity was also more often seen in the 3.0 T group compared with the 1.5 T group (88.7% vs 68.5%, respectively [P = 0.01]).

CONCLUSIONS

3.0 T MRI is more sensitive than 1.5 T MRI in detecting ON. This finding suggests that 3.0 T MRI is a preferred imaging modality for the confirmation of ON.

Development of a Prognostic Model for Predicting Multiple Sclerosis After Optic Neuritis: A Secondary Analysis of Data From the Optic Neuritis Treatment Trial

BACKGROUND

Optic neuritis can be the initial manifestation of multiple sclerosis (MS). The purpose of this study was to develop a prognostic model for predicting the risk of MS development among patients with optic neuritis.

METHODS

The data from 388 patients with optic neuritis were retrieved from the Optic Neuritis Treatment Trial (ONTT). Cox proportional hazards regression analysis was used to develop a prognostic model. The performance of the model was assessed by using Harrell's C-index and calibration curves. The rates of MS development were estimated using the Kaplan-Meier method.

RESULTS

Among the enrolled subjects, a total of 154 (39.7%) patients developed clinically definite MS during a median follow-up period of 15.8 years (interquartile range, 7.2-16.9 years). The factors associated with the development of MS were the presence of brain lesions as on baseline MRI, previous nonspecific neurologic symptoms, commencing low-dose corticosteroids treatment, ocular pain, and absence of optic disc/peripapillary hemorrhage. After incorporating these 5 factors into the prognostic model, a C-index of 0.72 (95% confidence interval [CI], 0.69-0.76) and good calibration curves were obtained. The C-index of the model was significantly higher than the C-indexes of any single factor (P < 0.001 in all cases). The model was able to stratify the ONTT patient cohort into 3 risk groups with significantly different intergroup rates of developing MS (rates for developing MS within a 15-year period: high-risk group, 75.7% [95% CI, 65.6%-82.9%], intermediate-risk group, 44.7% [95% CI, 31.4%-55.4%]; and low-risk group, 20.8% [95% CI, 14.2%-26.8%]; log-rank P < 0.001).

CONCLUSIONS

This prognostic model had a better prediction ability when compared with the standard practice that relies solely on using brain lesions on MRI. It can, therefore, help guide decision-making to initiate earlier disease-modifying therapy for patients with optic neuritis at risk of developing MS.

Optomyelitis associated with the presence of antibodies to myelin oligodendrocyte glycoprotein. Case report

Antibodies to myelin-oligodendrocyte glycoprotein (anti-MOG-IgG) is a specific biomarker that has been detected in peripheral blood from children with acute multiple encephalomyelitis (ADEM) as well as in adults with aquaporin-4 (AQP4), associated with seronegative opticoneuromyelitis spectrum disease (NMOSD), brainstem encephalitis, longitudinally disseminated transverse myelitis, and optic neuritis. Most experts now consider MOG-IgG-associated disorder (MOG-AD) an independent disease immunopathogenetically distinct from classical multiple sclerosis (MS) and aquaporin-4 (AQP4)-IgG-positive optomyelitis. Isolated, bilateral, and less frequently unilateral OH, with simultaneous or sequential involvement of the eyes, is the most frequent clinical manifestation of MOG-AD. Because of the significant overlap in the clinical and radiological picture, MOG-AD is often misdiagnosed as MS. Timely diagnosis is critical to ensure appropriate treatment. This article describes a clinical case of anti-MOG-IgG encephalomyelitis with late-onset ON initially diagnosed as MS.

OCT retinal nerve fiber layer thickness differentiates acute optic neuritis from MOG antibody-associated disease and Multiple Sclerosis: RNFL thickening in acute optic neuritis from MOGAD vs MS

BACKGROUND

Optic neuritis (ON) is the most common manifestation of myelin oligodendrocyte glycoprotein antibody associated disorder (MOGAD) and multiple sclerosis (MS). Acute ON in MOGAD is thought to be associated with more severe optic disk edema than in other demyelinating diseases, but this has not been quantitatively confirmed. The goal of this study was to determine whether optical coherence tomography (OCT) can distinguish acute ON in MOGAD from MS, and establish the sensitivity of OCT as a confirmatory biomarker of ON in these entities.

METHODS

This was a multicenter cross-sectional study of MOGAD and MS patients with peripapillary retinal nerve fiber layer (pRNFL) thickness measured with OCT within two weeks of acute ON symptom. Cirrus HD-OCT (Carl Zeiss Meditec, Inc. Dublin, CA, USA) was used to measure the pRNFL during acute ON. Eyes with prior ON or disk pallor were excluded. A receiver operating characteristic (ROC) curve analysis was performed to assess the ability of pRNFL thickness to distinguish MOGAD from MS.

RESULTS

Sixty-four MOGAD and 50 MS patients met study inclusion criteria. Median age was 46.5 years (interquartile range [IQR]: 34.3-57.0) for the MOGAD group and 30.4 years (IQR: 25.7-38.4) for the MS group (p<0.001). Thirty-nine (61%) of MOGAD patients were female compared to 42 (84%) for MS (p = 0.007). The median pRNFL thickness was 164 µm (IQR: 116-212) in 96 acute MOGAD ON eyes compared to 103 µm (IQR: 93-113) in 51 acute MS ON eyes (p<0.001). The ROC area under the curve for pRNFL thickness was 0.81 (95% confidence interval 0.74-0.88) to discriminate MOGAD from MS. The pRNFL cutoff that maximized Youden's index was 118 µm, which provided a sensitivity of 74% and specificity of 82% for MOGAD. Among 31 MOGAD and 48 MS eyes with an unaffected contralateral eye or a prior baseline, the symptomatic eye had a median estimated pRNFL thickening of 45 µm (IQR: 17-105) and 7.5 µm (IQR: 1-18), respectively (p<0.001). All MOGAD affected eyes had a ≥ 5 µm pRNFL thickening, whereas 26 (54%) MS affected eyes had a ≥ 5 µm thickening.

CONCLUSION

OCT-derived pRNFL thickness in acute ON can help differentiate MOGAD from MS. This can aid with early diagnosis and guide disease-specific therapy in the acute setting before antibody testing returns, and help differentiate borderline cases. In addition, pRNFL thickening is a sensitive biomarker for confirming acute ON in MOGAD, which is clinically helpful and could be used for adjudication of attacks in future MOGAD clinical trials.

Clinical profile, imaging features and short term visual outcomes of Indian optic neuritis patients with and without seromarkers for myelin oligodendrocyte glycoprotein and neuromyelitis optica

Purpose:

To analyze clinical profile, imaging features, and short-term visual outcomes of optic neuritis patients in Indian population with and without seromarkers for myelin oligodendrocyte glycoprotein (MOG)/neuromyelitis optica (NMO).

Methods:

Electronic medical records of 203 optic neuritis patients who presented between June 2018 and December 2019 to the Neuro-ophthalmology services of a tertiary care center in India were retrospectively analyzed.

Results:

Of 203 patients, 57 patients (28.08%) were positive for MOG-antibody and 20 patients (9.85%) were positive for NMO antibody. 114 patients (56.16%) were double-negative (negative for both antibodies) and 12 patients (5.91%) were diagnosed as multiple sclerosis (MS). None of the patients had both antibodies. Mean age of presentation was 31.29 ± 1.035 years. There was female preponderance in NMO-optic neuritis (NMO-ON) and MS-optic neuritis (MS-ON) groups (1:5). Mean vision on presentation was worse (logMAR 1.570 ± 0.863) in NMO-ON group. The mean visual acuity showed statistically significant recovery (logMAR 0.338 ± 0.639) in the final follow-up in MOG-optic neuritis (MOG-ON) group. Multivariate logistic regression analysis revealed poor visual outcome in patients presenting with retrobulbar neuritis, optic disc pallor, bilateral sequential optic nerve involvement, and with positive NMO antibody. Optic neuritis patients presenting with disc edema associated with pain and positive for MOG antibody were found to have a better visual outcome.

Conclusion:

In this Indian optic neuritis cohort, the prevalence of MOG-ON was higher than NMO-ON. MOG-ON had a better visual outcome than NMO-ON. The incidence of MS-ON was less compared to the western literature. A significant number of patients (114 patients, 56.16%) were double negative for both seromarkers and yet had presented with optic neuritis with no clinical or imaging features suggestive of MS/MOG associated disease (MOG AD)/NMO spectrum disorder (NMO SD).

Myelin Oligodendrocyte Glycoprotein Antibody-Associated Optic Neuritis-A Review

ABSTRACT

Our understanding of demyelinating optic neuritis has substantially evolved over the past 2 decades. With advancements in serological testing, antibodies against myelin oligodendrocyte glycoprotein (MOG) have been recently discovered in a distinct subset of demyelinating neuroinflammatory disease. Although MOG-immunoglobulin G (IgG)-associated disorder (MOGAD) has previously been seen as a component of neuromyelitis optica spectrum disorder (NMOSD), evidence increasingly suggests that it should be distinguished as a separate condition. The distinction of MOGAD from aquaporin-4 IgG NMOSD is imperative as treatment plans need to be tailored to its unique disease course and prognosis. The purpose of this review is to explore the nature and outcomes of MOGAD optic neuritis to help guide acute and long-term immunosuppressive treatment decisions.

Optic neuritis in Asian type opticospinal multiple sclerosis (OSMS-ON) in a non-Asian population: A functional-structural paradox

BACKGROUND

Biomarkers have improved the classification of autoimmune inflammatory disorders, including optic neuritis (ON) as a frequent presentation of multiple sclerosis, neuromyelitis spectrum disorders, MOG antibody-related disease (MOGAD), and opticospinal multiple sclerosis (OSMS). The phenotype of OSMS in non-Asian populations is less well known.

OBJECTIVE

We investigated the clinical features and prognosis of OSMS-ON in a Brazilian cohort.

METHODS

This was a single-center cohort study of patients from Rio de Janeiro (Brazil) with OSMS. All individuals were MOG- and AQP4-seronegative, clinically diagnosed with ON, and had magnetic resonance imaging-confirmed transverse myelitis (TM). Subjects and healthy controls (HCs) were assessed for visual acuity (logMAR VA), automated perimetry mean deviation (MD), intraocular pressure, and spectral-domain optical coherence tomography (OCT), followed by automated retinal layer segmentation of the peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell and inner plexiform layer (mGCIPL). Receiver operator characteristic curves were plotted and the area under the curve (AUC) was calculated for group comparisons of retinal asymmetry of the pRNFL and mGCIPL.

RESULTS

The 30 patients with OSMS were predominantly female and white. The mean age was 48 years (range 20-70 years). Unilateral ON was the index event in 83.3% of patients. Over the average 18-year follow-up period, there were 89 relapses of ON. In individuals with OSMS, the average VA was 0.07±0.14 in the right eye (RE) and 0.13±0.30 in the left eye (LE). The MD was -5.37±5.88 dB and -5.23±3.34 dB for the RE and LE, respectively. There was a significant cumulative loss of VA (p = 0.0003) and MD (p = 0.0001) with a higher number of recurrent episodes. Atrophy of the pRNFL thickness was significant in OSMS (RE, 78.62 ± 16.01 µm; LE, 79.86 ± 13.79 µm) relative to the HC group (RE, 98.87 ± 10.68 µm; LE, 97.87 ± 10.85 µm, p = 0.0001). Likewise, there was significant mGCIPL atrophy in patients with OSMS (RE, 74.96 ± 14.46 µm; LE, 73.88 ± 13.79 µm) relative to the HC group (RE, 90.50 ± 6.74 µm; LE, 90.41± 6.89 µm; p = 0.0001). Retinal asymmetry, inter-eye percentage, and absolute differences accurately separated patients with unilateral ON from HCs (AUC=0.89 and AUC=0.85, respectively).

CONCLUSION

A structural-functional paradox was found in OSMS with a high diagnostic value for a novel metric based on retinal asymmetry. The functional visual outcome are excellent despite significant structural damage to the inner retinal layers in patients with a high ON relapse rate and long-term bilateral sequential involvement.

Update on Optic Neuritis: An International View

Previously, optic neuritis was thought to be typical, i.e. idiopathic or multiple sclerosis (MS) related, associated with a good visual prognosis, or atypical, i.e. not associated with MS and requiring corticosteroids or plasma exchange for vision to recover. More recently, the importance of optic neuritis in neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein (MOG) antibody disease has become more appreciated. The results of the Optic Neuritis Treatment Trial (ONTT) has influenced how optic neuritis is treated around the world. For this review we surveyed the international literature on optic neuritis in adults. Our aims were first to find the reported incidence of optic neuritis in different countries and to ascertain what percentage of cases were seropositive for anti-aquaporin 4 and anti-MOG antibodies, and second, to document the presenting features, treatment, and outcomes from a first episode of the different types of optic neuritis from these countries, and to compare the results with the outcomes of the ONTT cohort. From these data we have sought to highlight where ambiguities currently lie in how to manage optic neuritis and have made recommendations as to how future treatment trials in optic neuritis should be carried out in the current antibody testing era.

At this Junction…

An 81-year-old woman developed painful vision loss to hand motions in the right eye over a several-day period. Dilated fundus examination revealed no acute pathology, but automated perimetry showed a superotemporal visual field defect in the asymptomatic left eye, suggestive of a junctional scotoma. Magnetic resonance imaging demonstrated enhancement of the right optic nerve extending to its junction with the optic chiasm. The patient's vision failed to improve with intravenous corticosteroids, but demonstrated significant improvement with therapeutic plasma exchange. She was subsequently found to be seropositive for aquaporin-4 autoantibodies, confirming the diagnosis of neuromyelitis optic spectrum disorder.

Optic neuritis classification in 2021

Optic neuritis (ON) can be associated with inflammatory disease of the central nervous system or can be isolated, with or without relapse. It can also be associated with infectious or systemic disease. These multiple associations based on a variety of clinical, radiological, and biological criteria that have changed over time have led to overlapping phenotypes: a single ON case can be classified in several ways simultaneously or over time. As early, intensive treatment is often required, its diagnosis should be rapid and precise. In this review, we present the current state of knowledge about diagnostic criteria for ON aetiologies in adults and children, we discuss overlapping phenotypes, and we propose a homogeneous classification scheme. Even if distinctions between typical and atypical ON are relevant, their phenotypes are largely overlapping, and clinical criteria are neither sensitive enough, nor specific enough, to assure a diagnosis. For initial cases of ON, clinicians should perform contrast enhanced MRI of the brain and orbits, cerebral spinal fluid analysis, and biological analyses to exclude secondary infectious or inflammatory ON. Systematic screening for MOG-IgG and AQP4-IgG IgG is recommended in children but is still a matter of debate in adults. Early recognition of neuromyelitis optica spectrum disorder, MOG-IgG-associated disorder, and chronic relapsing idiopathic optic neuritis is required, as these diagnoses require therapies for relapse prevention that are different from those used to treat multiple sclerosis.

Autoimmune Disorders of the Nervous System: Pathophysiology, Clinical Features, and Therapy

Remarkable discoveries over the last two decades have elucidated the autoimmune basis of several, previously poorly understood, neurological disorders. Autoimmune disorders of the nervous system may affect any part of the nervous system, including the brain and spinal cord (central nervous system, CNS) and also the peripheral nerves, neuromuscular junction and skeletal muscle (peripheral nervous system, PNS). This comprehensive overview of this rapidly evolving field presents the factors which may trigger breakdown of self-tolerance and development of autoimmune disease in some individuals. Then the pathophysiological basis and clinical features of autoimmune diseases of the nervous system are outlined, with an emphasis on the features which are important to recognize for accurate clinical diagnosis. Finally the latest therapies for autoimmune CNS and PNS disorders and their mechanisms of action and the most promising research avenues for targeted immunotherapy are discussed.

Recent advances on optic nerve magnetic resonance imaging and post-processing

The optic nerve is known to be one of the largest nerve bundles in the human central nervous system. There have been many studies of optic nerve imaging and post-processing that have provided insights into pathophysiology of optic neuritis related to multiple sclerosis and neuromyelitis optica spectrum disorder, glaucoma, and Leber's hereditary optic neuropathy. There are many challenges in optic nerve imaging, due to the morphology of the nerve through its course to the optic chiasm, its mobility due to eye movements and the high signal from cerebrospinal fluid and orbital fat surrounding the optic nerve. Recently, many advanced and fast imaging sequences have been used with post-processing techniques in attempts to produce higher resolution images of the optic nerve for evaluating various diseases. Magnetic resonance imaging (MRI) is one of the most common imaging methodologies for the optic nerve. This review paper will focus on recent MRI advances in optic nerve imaging and explain several post-processing techniques being used for analysis of optic nerve images. Finally, some challenges and potential for future optic nerve studies will be discussed.

Neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein associated disorder-optic neuritis: a comprehensive review of diagnosis and treatment

Optic neuritis (ON) is the most common cause of acute optic neuropathy in patients younger than 50 years of age and is most frequently idiopathic or associated with multiple sclerosis. However, the discovery of aquaporin-4 immunoglobulin G (IgG) and myelin oligodendrocyte glycoprotein (MOG)-IgG as biomarkers for two separate central nervous system inflammatory demyelinating diseases has revealed that neuromyelitis optica spectrum disorder (NMSOD) and MOG-IgG-associated disease (MOGAD) are responsible for clinically distinct subsets of ON. NMOSD-ON and MOGAD-ON both demonstrate tendencies for bilateral optic nerve involvement and often exhibit a relapsing course with the potential for devastating long-term visual outcomes. Early and accurate diagnosis is therefore essential. This review will summarize the current understanding of the clinical spectra of NMOSD and MOGAD, the radiographic and serological findings which support their diagnoses, and the current evidence behind various acute and long-term therapeutic strategies for ON related to these conditions. A particular emphasis is placed on a number of recent multi-centre randomized placebo-controlled trials, which provide the first level I evidence for long-term treatment of NMOSD.

Neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein IgG associated disorder: A comprehensive neuro-ophthalmic review

Neuromyelitis optica spectrum disorder (NMOSD) is an antibody-mediated inflammatory disease of the central nervous system that involves the optic nerves, spinal cord, and often other specific brain regions such as area postrema of the medulla. NMOSD was formerly classified as a variant of multiple sclerosis (MS), given the similar symptomatology and relapsing course but is now considered to have distinct clinical, paraclinical, immunological and prognostic features. The discovery of aquaporin 4 (AQP4) immunoglobulin G (IgG) has improved the ability to diagnose NMOSD. AQP4-IgG targets the astrocytic AQP4 water channel leading to complement activation and increased blood-brain barrier permeability. Accurate and early diagnosis is crucial as timely treatment may result in mitigation of long-term disability. Myelin oligodendrocyte glycoprotein (MOG)-IgG associated disorder (MOGAD) is a distinct nosologic entity, which has been more recently described. Its clinical spectrum partly overlaps that of seronegative NMOSD and MS. Although it is considered to have fewer relapses and better prognosis than NMOSD, the clinical course and outcome of MOGAD has not been fully characterized.

Atypical optic neuritis: An overview

Optic neuritis (ON) refers to conditions that involve inflammation of the optic nerve. Various autoantibodies have been found, which are associated with central nervous system inflammatory disorders and have provided much information about the immune targets and mechanisms that impact the prognosis, treatment, and recurrence of atypical ON. Therefore, neurologists and ophthalmologists together should work to find out clinical, laboratory, and imaging findings that may provide important clues to the etiology of atypical ON and its management. Various biomarkers have been identified to confirm and distinguish atypical optic neuritis from others. The purpose of this review is to present the current scenario of atypical ON and its clinical management.

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.

[Aquaporin-4 and Myelin Oligodendrocyte Glycoprotein Antibody-Associated Optic Neuritis: Diagnosis and Treatment]

Optic neuritis (ON) is a frequent manifestation of aquaporin-4 (AQP4) antibody-mediated neuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated encephalomyelitis (MOG-EM; also termed MOG antibody-associated disorders, MOGAD). The past few years have seen major advances in the diagnosis and treatment of these two relatively new entities: international diagnostic criteria for NMOSD and MOG-EM have been proposed, improved antibody assays developed, and consensus recommendations on the indications and methodology of serological testing published. Very recently, the results of four phase III trials assessing new treatment options for NMOSD have been presented. With eculizumab, a monoclonal antibody inhibiting complement factor C5, for the first time a relapse-preventing long-term treatment for NMOSD - which has so far mostly been treated off-label with rituximab, azathioprine, and other immunosuppressants - has been approved. Data from recent retrospective studies evaluating treatment responses in MOG-ON suggest that rituximab and other immunosuppressants are effective also in this entity. By contrast, many drugs approved for the treatment of multiple sclerosis (MS) have been found to be either ineffective or to cause disease exacerbation (e.g., interferon-β). Recent studies have shown that not only NMOSD-ON but also MOG-ON usually follows a relapsing course. If left untreated, both disorders can result in severe visual deficiency or blindness, though MOG-ON seems to have a better prognosis overall. Acute attacks are treated with high-dose intravenous methylprednisolone and, in many cases, plasma exchange (PEX) or immunoadsorption (IA). Early use of PEX/IA may prevent persisting visual loss and improve the long-term outcome. Especially MOG-ON has been found to be frequently associated with flare-ups, if steroids are not tapered, and to underlie many cases of "chronic relapsing inflammatory optic neuropathy" (CRION). Both NMOSD-ON and MOG-ON are often associated with simultaneous or consecutive attacks of myelitis and brainstem encephalitis; in contrast to earlier assumptions, supratentorial MRI brain lesions are a common finding and do not preclude the diagnosis. In this article, we review the current knowledge on the clinical presentation, epidemiology, diagnosis, and treatment of these two rare yet important differential diagnoses of both MS-associated ON und idiopathic autoimmune ON.

Beyond Giant Cell Arteritis and Takayasu's Arteritis: Secondary Large Vessel Vasculitis and Vasculitis Mimickers

PURPOSE OF REVIEW

To provide an overview of mimickers of large vessel vasculitis (LVV), by the main presenting manifestation, i.e., systemic, vascular, and cranial manifestations.

RECENT FINDINGS

The main differential diagnoses in patients with giant cell arteritis (GCA) and Takayasu arteritis (TAK) presenting with systemic manifestations (i.e., fever, anorexia, weight loss, night sweats, arthralgia/myalgia, and/or increased inflammatory indexes) are neoplastic, infectious, or other inflammatory conditions. In patients with vascular manifestations (such as peripheral ischemia, vascular stenoses, or aneurysms), atherosclerosis and non-inflammatory vascular diseases should be excluded. In those presenting with predominant cranial symptoms (i.e., temporal headache, jaw claudication, scalp tenderness, transient or permanent vision loss), other causes of headache, cerebrovascular accidents, optic neuropathy, and neuromuscular syndromes need to be considered. The diagnosis of LVV maybe challenging, especially when patients present with atypical or incomplete clinical forms. In these cases, a multidisciplinary approach is strongly recommended.

Etiologies of Acute Optic Neuritis in Thailand: An Observational Study of 171 Patients

Purpose

To analyze the demographic patterns, clinical characteristics and etiologies of acute optic neuritis (ON).

Methods

This retrospective observational study included patients with acute ON who presented to a university hospital in Bangkok, Thailand, between January 2010 and March 2020. The demographic details, clinical characteristics and etiologies of acute ON were evaluated.

Results

A total of 171 patients were included in the study (78.4% [n=134] female; mean age 45 years [standard deviation 15.4 years]; 32.2% [n=55] bilateral involvement). The most common type of acute ON was idiopathic (51.5%), followed by neuromyelitis optica spectrum disorder (NMOSD, 30.9%), other autoimmune disorders (9.9%), myelin oligodendrocyte glycoprotein antibody-associated disorder (MOGAD, 5.3%), multiple sclerosis (MS, 1.8%), and postinfection (0.6%). In the other autoimmune disorders group, 2 patients developed systemic lupus erythematosus (1.2%), 2 Sjogren’s syndrome (1.2%), 1 RA (0.6%), 1 anti-NMDAR (0.6%), 3 anti-Jo1 (1.8%), 2 c-ANCA (1.2%), 1 anti-centromere (0.6%), and 5 nonspecific autoimmune disorders (2.9%). In the idiopathic group, 38.6% developed single isolated ON, 1.8% relapsing isolated ON and 11.1% chronic relapsing inflammatory optic neuropathy.

Conclusion

The most common form of acute ON in this study, similar to other Asian countries, was idiopathic. Idiopathic-ON shared some phenotypes with NMOSD and MOGAD. We also reported patients with anti-NMDAR, anti-Jo1, c-ANCA and anti-centromere disorders. Improvements in antibody detection have widened the range of possible etiologies of acute ON. The study highlighted the important role of antibodies in creating effective treatments in the future.

Rapid Administration of High-Dose Intravenous Methylprednisolone Improves Visual Outcomes After Optic Neuritis in Patients With AQP4-IgG-Positive NMOSD

Objective: The purpose of this study was to elucidate the rapid impact of high-dose intravenous methylprednisolone pulse therapy (1,000 mg/day for 3 days) on the eventual visual prognosis in patients with serum anti-aquaporin-4 immunoglobulin G (AQP4-IgG)–positive neuromyelitis optica spectrum disorders (NMOSDs) who had an attack of optic neuritis (ON).

Methods: Data from 32 consecutive NMOSD patients (1 male and 31 female) with at least one ON attack, involving a total of 36 ON-involved eyes, were evaluated. The following variables at ON onset were evaluated: sex, age at the first ON episode, visual acuity at nadir, visual acuity after 1 year, duration from ON onset to treatment for an acute ON attack, cycles of high-dose intravenous methylprednisolone pulse therapy for the ON attack, and cycles of plasmapheresis for the ON attack. Among the 36 ON-involved eyes, 27 eyes were studied using orbital MRI with a short-T1 inversion recovery sequence and gadolinium-enhanced fat-suppressed T1 imaging before starting treatment in the acute phase.

Results: In univariate analyses, a shorter duration from ON onset to the initiation of high-dose intravenous methylprednisolone pulse therapy favorably affected the eventual visual prognosis 1 year later (Spearman's rho = 0.50, p = 0.0018). The lesion length on orbital MRI was also correlated with the eventual visual prognosis (rho = 0.68, p < 0.0001). Meanwhile, the days to steroid pulse therapy and lesion length on orbital MRI did not show a significant correlation. These findings suggest that the rapidness of steroid pulse therapy administration affects the eventual visual prognosis independent of the severity of ON. In multivariate analysis, a shorter time from ON onset to the start of acute treatment (p = 0.0004) and a younger age at onset (p = 0.0071) were significantly associated with better visual outcomes.

Conclusions: Rapid initiation of high-dose intravenous methylprednisolone pulse therapy is essential to preserve the eventual visual acuity in patients with serum AQP4-IgG-positive NMOSD. Once clinicians suspect acute ON with serum AQP4-IgG, swift administration of steroid pulse therapy before confirming the positivity of serum AQP4-IgG would be beneficial for preserving visual function.

Understanding Pediatric Neuroimmune Disorder Conflicts: A Neuroradiologic Approach in the Molecular Era

Neuroimmune disorders in children are a complex group of inflammatory conditions of the central nervous system with diverse pathophysiologic mechanisms and clinical manifestations. Improvements in antibody analysis, genetics, neuroradiology, and different clinical phenotyping have expanded knowledge of the different neuroimmune disorders. The authors focus on pediatric-onset myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease, which is a new entity in the spectrum of inflammatory demyelinating diseases, distinct from both multiple sclerosis (MS) and anti-aquaporin-4 (AQP4) antibody neuromyelitis optica spectrum disorders (NMOSDs). The authors review the importance of an optimized antibody-detection assay, the frequency of MOG antibodies in children with acquired demyelinating syndrome (ADS), the disease course, the clinical spectrum, proposed diagnostic criteria, and neuroimaging of MOG antibody-associated disease. Also, they outline differential diagnosis from other neuroimmune disorders in children according to the putative primary immune mechanism. Finally, they recommend a diagnostic algorithm for the first manifestation of ADS or relapsing ADS that leads to four demyelinating syndromes: MOG antibody-associated disease, AQP4 antibody NMOSDs, MS, and seronegative relapsing ADS. This diagnostic approach provides a framework for the strategic role of neuroradiology in diagnosis of ADS and decision making, to optimize patient care and treatment outcome in concert with clinicians. Online supplemental material is available for this article. ^©RSNA, 2020.

Molecular Biomarkers in Multiple Sclerosis and Its Related Disorders: A Critical Review

Multiple sclerosis (MS) is a chronic autoimmune disease affecting the central nervous system (CNS) which can lead to severe disability. Several diseases can mimic the clinical manifestations of MS. This can often lead to a prolonged period that involves numerous tests and investigations before a definitive diagnosis is reached. As well as the possibility of misdiagnosis. Molecular biomarkers can play a unique role in this regard. Molecular biomarkers offer a unique view into the CNS disorders. They help us understand the pathophysiology of disease as well as guiding our diagnostic, therapeutic, and prognostic approaches in CNS disorders. This review highlights the most prominent molecular biomarkers found in the literature with respect to MS and its related disorders. Based on numerous recent clinical and experimental studies, we demonstrate that several molecular biomarkers could very well aid us in differentiating MS from its related disorders. The implications of this work will hopefully serve clinicians and researchers alike, who regularly deal with MS and its related disorders.

Autoimmune and demyelinating optic neuritis

The knowledge on demyelinating and autoimmune optic neuropathies has experienced a revolution the last decade since the discovery of anti-aquaporin 4 antibody. Improvements in diagnostic techniques, and the finding of new targets, along with advances in neuro-immunology have led to the detection of antibodies related to demyelinating diseases. A review is presented on the classical and new concepts in optic neuritis. The debate on the classification of demyelinating and autoimmune optic neuritis is presented. Furthermore, the updated diagnostic criteria in multiple sclerosis and neuro-myelitis optics are described. Finally, the latest insights into Myelin Oligodendrocyte Glycoprotein (MOG) disorders and chronic-recurring optic neuropathies (CRION) are highlited.

A tearfully painful darkness

A 70-year-old woman presented with new onset of left eye and facial pain. Ophthalmic and neurological examinations, magnetic resonance imaging brain, erythrocyte sedimentation rate, and C-reactive protein were unrevealing. A few days later, she developed vision loss in her left eye. Examination revealed decreased visual acuity with a relative afferent pupillary defect in the left eye and a diffuse mild swelling of the left optic nerve head. Repeat magnetic resonance imaging showed T2 hyperintensity and enhancement of the intraorbital optic nerve and surrounding tissues with no other intracranial abnormalities. Serum studies showed elevated myelin oligodendrocyte glycoprotein IgG titer. She was treated with IV methylprednisolone 1000 mg daily for 3 days and was discharged on prolonged prednisone taper with return of vision to baseline.