Radiological differentiation of optic neuritis with myelin oligodendrocyte glycoprotein antibodies, aquaporin-4 antibodies, and multiple sclerosis

Brain and Spine Magnetic Resonance Imaging (MRI) Characteristics of a Pediatric Cohort With MOGAD

BACKGROUND AND OBJECTIVES

Myelin-oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently defined demyelinating disorder with an age-related phenotypic spectrum. At disease onset, there is considerable clinical overlap between MOGAD and other demyelinating conditions, and it remains difficult to identify MOGAD radiographically. This study aims to further describe neuroimaging findings in the brain and the spine at presentation and throughout relapses in children with MOGAD.

METHODS

We present a retrospective cohort study including all children presenting to a single center between 2010 and 2020 with acute demyelination who were positive for serum MOG-IgG antibodies and negative for serum aquaporin-4 antibodies. For each patient, magnetic resonance imaging (MRI) scans of the brain and spine at presentation and on each relapse were reviewed and categorized in a blinded fashion by 2 pediatric neuroradiologists.

RESULTS

Sixteen patients met the inclusion criteria. Four had diffuse and bilateral fluid-attenuated inversion recovery signal in the white matter, but only on initial presentation. The area postrema was never affected. All 5 patients with optic neuritis had pre-chiasmatic (but not chiasmatic) involvement on presentation. The brachium pontis was involved in 3 patients on initial presentation, and in 8 patients at any time. Eleven patients demonstrated spinal cord involvement, and the cervical, thoracic, and lumbar regions were involved at similar frequencies.

DISCUSSION

The radiographic features of MOGAD in children appear to reflect their presenting demyelinating syndromes. However, certain features, such as diffuse fluid-attenuated inversion recovery hyperintensities and expansile fluid-attenuated inversion recovery signal in the brachium pontis, may be more frequent in MOGAD compared with other demyelinating disorders.

Barriers in Healthcare to the Use of Optical Coherence Tomography Angiography in Multiple Sclerosis

Optical coherence tomography angiography (OCT-A) is a state-of-the-art imaging technique for the retinal vasculature to accurately segment the capillary network and assign it to retinal layers. OCT-A is a promising technique to better understand neurological diseases with visual system manifestations, such as multiple sclerosis (MS), and to identify and characterize vascular biomarkers. Initial studies suggested vascular changes in MS and its differential diagnoses such as myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and neuromyelitis optica spectrum disorder (NMOSD). Here we review clinical and technical aspects of OCT-A imaging and discuss the potential for the MS field as well as barriers that need to be overcome before OCT-A can be established in clinical application.

Typical and Emerging Diagnostic MRI Features in Multiple Sclerosis

Magnetic resonance imaging (MRI) stands as the most sensitive paraclinical technique for detecting the demyelinating lesions characteristic of multiple sclerosis (MS). Consequently, MRI plays a pivotal role in establishing an accurate and timely diagnosis of the disease, ultimately based on the application of the McDonald criteria. Early diagnosis is particularly important as it facilitates the prompt initiation of disease-modifying treatments, deemed most effective during the initial phases of MS. This review article examines the recommended standardized MRI protocol, as well as the classic imaging features of MS in the brain, optic nerve, and spinal cord, capable of discriminating, in most cases, MS from other disorders that can mimic this disease. Additionally, novel MR imaging findings, such as the central vein sign and paramagnetic rim lesion, which have been proposed as new imaging biomarkers to enhance diagnostic specificity for MS, are also discussed. These emerging features are likely to be incorporated in the future iterations of the McDonald criteria, and therefore, radiologists should be familiar with their appearance and with the optimal MRI protocols required for their detection.

Pain and Headache in Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease

PURPOSE OF REVIEW

The purpose of this review is to evaluate the current knowledge and recent findings on different pain and headache presentations associated with Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD) disease.

RECENT FINDINGS

MOGAD is an inflammatory autoimmune disease affecting mostly the central nervous system, presenting with optic neuritis, transverse myelitis and other forms of inflammatory demyelination. Pain and headache in MOGAD have been recognized more recently and acute and chronic forms of pain can occur in both the adult and pediatric population. An important recent observation is that MOGAD can affect the peripheral nervous system, which can contribute to pain symptoms. Acute and chronic forms of pain have been described in MOGAD, including ocular pain, different types of headaches and neuropathies, involving the central and peripheral nervous system. Awareness of these types of pain in both the pediatric and adult population is crucial, to ensure timely diagnosis and treatment.

Case report: Overlapping syndrome of MOG-IgG associated optic neuritis and autoimmune encephalitis with co-existence of anti-NMDAR and anti-GABABR antibodies

We report a case of optic neuritis (ON) secondary to autoimmune encephalitis (AE) in a patient with concomitant antibodies to N-methyl-D-aspartate receptor (NMDAR), gamma-aminobutyric acid-B receptor (GABABR), and myelin oligodendrocyte glycoprotein (MOG). The patient exhibited a constellation of symptoms, including vision loss, seizures, mental and behavioral disorders, cognitive impairment, and speech abnormalities. At the two-year follow-up, the patient's symptoms had abated entirely. Overlap syndrome of triple autoimmune antibodies is rare and the coexistence of antibodies to NMDAR, GABABR and MOG has not been reported till now. This case report provides novel experience of diagnosis and treatment in autoimmune overlap syndromes.

MOGAD: A comprehensive review of clinicoradiological features, therapy and outcomes in 4699 patients globally

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is one of the most common antibody-mediated CNS disorders. Optimal diagnostic and prognostic biomarkers remain unclear. Our aim was to clarify these biomarkers and therapeutic outcomes internationally. We reviewed articles from 2007 to 2022 and identified 194 unique cohorts encompassing 4699 paediatric and adult patients from 31 countries. Where phenotypes were specified, the most common initial presentation overall was optic neuritis (ON; paediatric 34 %; adults 60 %), during which 71 % had papilloedema on fundoscopy. The most common phenotype at latest follow-up was relapsing ON (20 %). Only 47 % of patients with 6-24 months of follow-up exhibited a relapsing course, while this proportion was much higher (72 %) when follow-up was extended beyond 5 years. Despite a similar relapse rate, the time to first relapse was much shorter in paediatric than adult patients (6 vs 17 months). Adult MRI-Brain scans performed at onset were more frequently normal than in paediatric patients (50 % vs 27 %). Abnormal MRI scans showing involvement of deep grey matter, cortico-subcortical, periventricular lesions, leptomeningeal enhancement, H-shaped spinal cord lesions, and bilateral optic nerve abnormalities were more common in paediatric patients compared to adults. Conversely, adults demonstrated higher frequencies of eccentric spinal cord lesions and intraorbital involvement. CSF analysis demonstrated intrathecally restricted oligoclonal bands in 12 %, elevated protein in 35 %, and pleocytosis in 54 %. Peripapillary retinal nerve fibre layer (pRNFL) thickness, measured acutely, frequently demonstrated swelling (weighted-median 145 μm; normal 85-110). Most cohorts demonstrated notable pRNFL atrophy at latest follow-up (weighted-median 67 μm). pRNFL thickness was significantly lower when measured at or after six months following ON onset, compared to measurements taken within the first six months following ON onset (p < 0.001). Therapeutic and outcome data was available for 3031 patients with a weighted-median disease duration of 32 months. Acute immunotherapy was initiated in 97 %, and maintenance immunotherapy in 64 %, with considerable regional variation. Expanded Disability Status Scale (EDSS) scores and visual acuities improved from nadir to latest follow-up in most patients. A negative correlation was noted between follow-up pRNFL thickness and latest follow-up visual acuity (r = -0.56). Based on this unprecedented global aggregation of MOGAD patients, we reveal a higher proportion of relapsing patients than previously recognised. While commonly used measures like EDSS show significant recovery, they underestimate visual disability following optic neuritis, the most frequent clinical presentation. Our findings suggest that RNFL thickness, especially when measured at least 6 months post-ON, may serve as a more sensitive biomarker for long-term visual impairment.

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.

MOG-IgG is rare in AQP4-IgG seronegative NMO phenotype in Brazil

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disease most frequently characterized by a neuromyelitis optica (NMO) phenotype, comprising both simultaneous or sequential optic neuritis (ON) and longitudinally extensive transverse myelitis (LETM). Symptoms of brainstem, diencephalic and cerebral involvement may also occur. While most NMOSD patients test positive for serum aquaporin-4 (AQP4) antibodies, some seronegative patients test positive for oligodendrocyte glycoprotein-IgG (MOG-IgG). Early identification of seropositive MOG-IgG seropositive patients among those with AQP4-IgG seronegative NMO phenotype may impact disease treatment and outcome.

OBJECTIVE

To determine the frequency of MOG-IgG in patients with AQP4-IgG seronegative NMO phenotype at a single reference center in Brazil and to analyze factors influencing their identification.

METHODS

A retrospective review of medical records of patients who presented with NMO phenotype and met the 2015 IPND criteria for NMOSD without AQP4 antibodies was conducted in a single center in Brazil. Patients were tested for serum AQP4 antibodies and retrospectively for MOG-IgG using cell-based assays. In addition to demographic, clinical, and imaging data, information on time intervals between disease onset and MOG-IgG testing, as well as the most recent relapse to MOG-IgG testing, was collected.

RESULTS

Out of 118 patients tested for MOG-IgG, 28 (23.7 %) presented with NMO phenotype and met the 2015 IPND criteria for NMOSD without AQP4-IgG. Three (10.7 %) of them tested positive for MOG-IgG serostatus. All were females and had a median age of 26 (11-34) years at disease presentation. The median disease duration was 11.2 yrs. Two patients had a relapsing course. Optic neuritis, myelitis, and brainstem syndrome were the most common presenting symptoms. The median annualized relapse rate was 0.25, and the median EDSS score at the most recent visit was 2.0 (1.5-5.0). There were 25 double seronegative patients, 21 (84 %) of whom were female and non-Caucasian; the median age at disease onset was 30 years (2-60), and the median EDSS at most recent visit was 4.0 (0 - 8.0).

DISCUSSION

The study identified MOG-IgG antibodies in 10.7 % of a cohort with AQP4-IgG seronegative NMO phenotype. Immunosuppressive treatment and long intervals between disease attacks and antibody testing may have impacted the frequency of MOG-IgG seropositivity. As MOG-IgG testing is crucial for diagnosing MOGAD in AQP4-IgG seronegative NMO phenotype, we highlight the need for broader and timely testing to improve diagnostic accuracy in resource-limited settings.

Magnetic resonance imaging-based biomarkers of multiple sclerosis and neuromyelitis optica spectrum disorder: a systematic review and meta-analysis

BACKGROUND/OBJECTIVE

Multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) are neuroinflammatory conditions with overlapping clinical and imaging features. Distinguishing between these diseases is crucial for appropriate diagnosis and management. Magnetic resonance imaging (MRI) may have the potential to differentiate these disorders. Nonetheless, studies exhibit inconsistencies regarding which MRI measurements most effectively distinguish between these disorders. Hence, this review aimed to evaluate the differences in MRI volumetry between people with MS (PwMS) and people with NMOSD (PwNMOSD).

METHODS

A systematic search was conducted across PubMed/MEDLINE, Embase, Scopus, and Web of Science up to May 12, 2024, to identify studies assessing conventional and volumetric MRI in PwMS and PwNMOSD. The standard mean difference (SMD) of MRI measurements and its 95% confidence interval (CI) were estimated using R version 4.4.0 with a random-effects model.

RESULTS

Forty-eight original studies that assessed conventional MRI measurements in 2592 PwMS and 1979 PwNMOSD were included. The meta-analysis revealed that PwMS had significantly higher T2 lesion volume (SMD = 1.51, 95% CI: 0.53 to 2.48, p = 0.002) and T1 lesion count (SMD = 1.08, 95% CI: 0.56 to 1.6, p < 0.001) than PwNMOSD. PwMS also exhibited significantly reduced thalamic volume (SMD = -1.26, 95% CI: -1.8 to -0.73, p < 0.001) and grey matter volume (GMV) (SMD = -0.65, 95% CI: -0.92 to -0.37, p < 0.001). Other MRI volumetry, such as the brain and putamen volumes, showed more pronounced atrophy in PwMS.

CONCLUSION

Significant differences in MRI volumetry between MS and NMOSD highlight the potential of MRI as a critical diagnostic tool. These findings emphasize the need for standardized MRI protocols and advanced imaging techniques to enhance diagnostic accuracy and clinical management of these conditions.

A role for vessel-associated extracellular matrix proteins in multiple sclerosis pathology

Multiple sclerosis (MS) is unsurpassed for its clinical and pathological hetherogeneity, but the biological determinants of this variability are unknown. HLA-DRB1*15, the main genetic risk factor for MS, influences the severity and distribution of MS pathology. This study set out to unravel the molecular determinants of the heterogeneity of MS pathology in relation to HLA-DRB1*15 status. Shotgun proteomics from a discovery cohort of MS spinal cord samples segregated by HLA-DRB*15 status revealed overexpression of the extracellular matrix (ECM) proteins, biglycan, decorin, and prolargin in HLA-DRB*15-positive cases, adding to established literature on a role of ECM proteins in MS pathology that has heretofore lacked systematic pathological validation. These findings informed a neuropathological characterisation of these proteins in a large autopsy cohort of 41 MS cases (18 HLA-DRB1*15-positive and 23 HLA-DRB1*15-negative), and seven non-neurological controls on motor cortical, cervical and lumbar spinal cord tissue. Biglycan and decorin demonstrate a striking perivascular expression pattern in controls that is reduced in MS (-36.5%, p = 0.036 and - 24.7%, p = 0.039; respectively) in lesional and non-lesional areas. A concomitant increase in diffuse parenchymal accumulation of biglycan and decorin is seen in MS (p = 0.015 and p = 0.001, respectively), particularly in HLA-DRB1*15-positive cases (p = 0.007 and p = 0.046, respectively). Prolargin shows a faint parenchymal pattern in controls that is markedly increased in MS cases where a perivascular deposition pattern is observed (motor cortex +97.5%, p = 0.001; cervical cord +49.1%, p = 0.016). Our findings point to ECM proteins and the vascular interface playing a central role in MS pathology within and outside the plaque area. As ECM proteins are known potent pro-inflammatory molecules, their parenchymal accumulation may contribute to disease severity. This study brings to light novel factors that may contribute to the heterogeneity of the topographical variation of MS pathology.

NMOSD and MOGAD: an evolving disease spectrum

Neuromyelitis optica (NMO) spectrum disorder (NMOSD) is a relapsing inflammatory disease of the CNS, characterized by the presence of serum aquaporin 4 (AQP4) autoantibodies (AQP4-IgGs) and core clinical manifestations such as optic neuritis, myelitis, and brain or brainstem syndromes. Some people exhibit clinical characteristics of NMOSD but test negative for AQP4-IgG, and a subset of these individuals are now recognized to have serum autoantibodies against myelin oligodendrocyte glycoprotein (MOG) - a condition termed MOG antibody-associated disease (MOGAD). Therefore, the concept of NMOSD is changing, with a disease spectrum emerging that includes AQP4-IgG-seropositive NMOSD, MOGAD and double-seronegative NMOSD. MOGAD shares features with NMOSD, including optic neuritis and myelitis, but has distinct pathophysiology, clinical profiles, neuroimaging findings (including acute disseminated encephalomyelitis and/or cortical encephalitis) and biomarkers. AQP4-IgG-seronegative NMOSD seems to be a heterogeneous condition and requires further study. MOGAD can manifest as either a monophasic or a relapsing disease, whereas NMOSD is usually relapsing. This Review summarizes the history and current concepts of NMOSD and MOGAD, comparing epidemiology, clinical features, neuroimaging, pathology and immunology. In addition, we discuss new monoclonal antibody therapies for AQP4-IgG-seropositive NMOSD that target complement, B cells or IL-6 receptors, which might be applied to MOGAD in the near future.

The influence of MOGAD on diagnosis of multiple sclerosis using MRI

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is an immune-mediated demyelinating disease that is challenging to differentiate from multiple sclerosis (MS), as the clinical phenotypes overlap, and people with MOGAD can fulfil the current MRI-based diagnostic criteria for MS. In addition, the MOG antibody assays that are an essential component of MOGAD diagnosis are not standardized. Accurate diagnosis of MOGAD is crucial because the treatments and long-term prognosis differ from those for MS. This Expert Recommendation summarizes the outcomes from a Magnetic Resonance Imaging in MS workshop held in Oxford, UK in May 2022, in which MS and MOGAD experts reflected on the pathology and clinical features of these disorders, the contributions of MRI to their diagnosis and the clinical use of the MOG antibody assay. We also critically reviewed the literature to assess the validity of distinctive imaging features in the current MS and MOGAD criteria. We conclude that dedicated orbital and spinal cord imaging (with axial slices) can inform MOGAD diagnosis and also illuminate differential diagnoses. We provide practical guidance to neurologists and neuroradiologists on how to navigate the current MOGAD and MS criteria. We suggest a strategy that includes useful imaging discriminators on standard clinical MRI and discuss imaging features detected by non-conventional MRI sequences that demonstrate promise in differentiating these two disorders.

Relapse-Independent disease activity in neuromyelitis optica spectrum disorder: A systematic review

INTRODUCTION

Neuromyelitis Optica Spectrum Disorders (NMOSD) is a neuroinflammatory condition characterized by optic neuritis and transverse myelitis. While the current approach to NMOSD focuses on relapse-associated worsening (RAW), recent evidence indicates Relapse-Independent Disease Activity (RIDA) in patients.

METHOD

Databases including Embase, PubMed, Scopus, and Web of Sciences were systematically searched up to December 2023. No restrictions were applied. Inclusion criteria focused on studies reporting evidence of RIDA in NMOSD patients. Data extraction involved details such as study title, author, participant characteristics, treatment, evaluation methods, positive findings according to RIDA, and prevalence of findings in NMOSD patients. This study is conducted following the PRISMA guidelines with a registered protocol on PROSPERO (ID = CRD42023492352).

RESULT

Of 802 studies, 38 were included in the systematic review, covering 1881 NMOSD patients. AQP4-IGg status was positive in 90.6 % of the patients. Ocular findings indicative of RIDA were reported in 23 studies, including thinning of GCIPL, RNFL, GCC, and GCL layers, foveal and macular shape and volume abnormalities, vessel loss, and visual evoked potentials (VEPs) abnormalities. MRI findings supporting the RIDA were reported in 13 studies, including new lesion incidence and brain and spinal cord atrophy. Serum and CSF RIDA-supporting findings were reported in five studies, including elevation in sGFAP and sNFL. Biopsies and autopsies suggested inflammatory processes in relapse-free patients in 2 studies. The predominant manifestation of RIDA in NMOSD was identified in the visual system, suggesting the impaired retinal glial cells like Müller cells during the relapse-free period in NMOSD.

INTERPRETATION

Our systematic review provides valuable insights into RIDA in NMOSD. Establishing guidelines for the diagnosis and treatment of RIDA is crucial. Further studies are needed to provide robust evidence on RIDA in NMOSD patients.

Nontraumatic Pediatric Head and Neck Emergencies: Resource for On-Call Radiologists

The vast array of acute nontraumatic diseases encountered in the head and neck of pediatric patients can be intimidating for radiologists in training in a fast-paced emergency setting. Although there is some overlap of pediatric and adult diseases, congenital lesions and developmental variants are much more common in the pediatric population. Furthermore, the relative incidences of numerous infections and neoplasms differ between pediatric and adult populations. Young patients and/or those with developmental delays may have clinical histories that are difficult to elicit or nonspecific presentations, underscoring the importance of imaging in facilitating accurate and timely diagnoses. It is essential that radiologists caring for children be well versed in pediatric nontraumatic head and neck emergency imaging. The authors provide an on-call resource for radiology trainees, organized by anatomic location and highlighting key points, pearls, pitfalls, and mimics of many acute nontraumatic diseases in the pediatric head and neck. ©RSNA, 2024 Supplemental material is available for this article.

Investigating the 2023 MOGAD Criteria in Children and Adults With MOG-Antibody Positivity Within and Outside Attacks

BACKGROUND AND OBJECTIVES

The 2023 criteria for myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) perform well in adults but have not been assessed in children.

METHODS

This prospective observational nationwide study includes children and adults with demyelinating syndromes or encephalitis, whose serum or CSF was found MOG-immunoglobulin G (IgG) positive at Institut d'Investigacions Biomèdiques August Pi i Sunyer-Hospital Clínic of Barcelona (Spain). Exclusion criteria were lack of clinical information and follow-up <1 year, and serum unavailable for antibody testing. The primary outcome was to assess the accuracy of the 2023 MOGAD criteria, using as gold standard the most plausible diagnosis after a follow-up >1 year. MOGAD criteria were retrospectively applied assessing core syndromes, supportive clinical-radiological features, and MOG-IgG titers. Patients tested ≤3 months of a disease attack (acute phase) or afterward (remission) were considered separately. The positive predictive value (PPV) of the criteria (true-positive [patients classified as MOGAD and MOGAD diagnosis last follow-up] divided by total positive [all patients classified as MOGAD]), and its 95% CI, was calculated with the Wilson procedure.

RESULTS

A total of 257 patients (133 children) were included in the study (median age 15 years [interquartile range 6-38], 54% female). Among 202 patients assessed during a disease attack, 158 (78%) had high MOG-IgG serum titers, 36 (18%) low titers, and 8 (4%) antibodies only in CSF. No differences were identified between patients with high and low titers, but those with low titers were more likely to have an alternative diagnosis at last follow-up (2/36 [6%] vs 0/158, p = 0.012). Supportive features were present in 230 of 257 (89%) patients, regardless of age, MOG-IgG titers, and core syndromes except for optic neuritis in adults whose assessment with orbital MRI was not systematic. Overall, 240 of 257 (94%) patients were well classified by the MOGAD criteria (e.g., 236 eventually having MOGAD and 4 alternative diagnoses), and 17 were wrongly classified (e.g., 11 eventually having MOGAD and 6 alternative diagnoses). Although the criteria classified better during disease attacks than during remissions (187 [96%] vs 49 [89%] serum MOG-IgG-positive patients were well-classified, p = 0.038), the PPV was high in both settings (99% [95% CI 97-100] vs 98% [95% CI 89-100]).

DISCUSSION

The 2023 MOGAD criteria correctly identified most children and adults with MOGAD. The highest accuracy occurred when they were applied during disease attacks.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that the 2023 MOGAD criteria accurately identify adults and children with MOGAD.

Radiological features in pediatric myelin oligodendrocyte glycoprotein antibody-associated disease-diagnostic criteria and lesion dynamics

The spectrum of acquired pediatric demyelinating syndromes has been expanding over the past few years, to include myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), as a distinct neuroimmune entity, in addition to pediatric-onset multiple sclerosis (POMS) and aquaporin 4-IgG-seropositive neuromyelitis optica spectrum disorder (AQP4+NMOSD). The 2023 MOGAD diagnostic criteria require supporting clinical or magnetic resonance imaging (MRI) features in patients with low positive myelin oligodendrocyte glycoprotein IgG titers or when the titers are not available, highlighting the diagnostic role of imaging in MOGAD. In this review, we summarize the key diagnostic features in MOGAD, in comparison to POMS and AQP4+NMOSD. We describe the lesion dynamics both during attack and over time. Finally, we propose a guideline on timing of imaging in clinical practice.

A Case of Myelin Oligodendrocyte Glycoprotein Antibody Disease in a Pediatric Patient: Clinical Presentation, Treatment Response, and Follow-Up Considerations

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is a rare autoimmune demyelinating disorder that targets the central nervous system and is characterized by antibodies that act against myelin oligodendrocyte glycoprotein (MOG). This disorder typically manifests with symptoms such as optic neuritis, transverse myelitis, or encephalitis, leading to symptoms such as vision loss, muscle weakness, sensory disturbances, and cognitive impairment. We present the case of a 10-year-old male who was eventually diagnosed with MOGAD after consideration of several other neurological and musculoskeletal disorders, who was admitted to the hospital due to an initial presentation of urinary retention and pelvic pain. The patient's clinical course included an MRI scan showing extensive demyelinating lesions in the spinal cord, along with positive MOG antibody serology. Management involved a multidisciplinary approach, including consultations from neurology, physical therapy, and the general pediatrics team, as well as administration of high-dose corticosteroids. This case underscores the importance of early recognition and aggressive treatment of MOGAD, a disorder that can present similarly to other demyelinating diseases such as multiple sclerosis and neuromyelitis optica spectrum disorder, with the distinguishing feature of MOGAD being the presence of antibodies against MOG.

Retinal Changes in Double-Antibody Seronegative Neuromyelitis Optica Spectrum Disorders

BACKGROUND AND OBJECTIVES

To systematically describe the clinical picture of double-antibody seronegative neuromyelitis optica spectrum disorders (DN-NMOSD) with specific emphasis on retinal involvement.

METHODS

Cross-sectional data of 25 people with DN-NMOSD (48 eyes) with and without a history of optic neuritis (ON) were included in this study along with data from 25 people with aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorder (AQP4-NMOSD, 46 eyes) and from 25 healthy controls (HCs, 49 eyes) for comparison. All groups were matched for age and sex and included from the collaborative retrospective study of retinal optical coherence tomography (OCT) in neuromyelitis optica (CROCTINO). Participants underwent OCT with central postprocessing and local neurologic examination and antibody testing. Retinal neurodegeneration was quantified as peripapillary retinal nerve fiber layer thickness (pRNFL) and combined ganglion cell and inner plexiform layer thickness (GCIPL).

RESULTS

This DN-NMOSD cohort had a history of [median (inter-quartile range)] 6 (5; 9) attacks within their 5 ± 4 years since onset. Myelitis and ON were the most common attack types. In DN-NMOSD eyes after ON, pRNFL (p < 0.001) and GCIPL (p = 0.023) were thinner compared with eyes of HCs. Even after only one ON episode, DN-NMOSD eyes already had considerable neuroaxonal loss compared with HCs. In DN-NMOSD eyes without a history of ON, pRNFL (p = 0.027) and GCIPL (p = 0.022) were also reduced compared with eyes of HCs. However, there was no difference in pRNFL and GCIPL between DN-NMOSD and AQP4-NMOSD for the whole group and for subsets with a history of ON and without a history of ON-as well as between variances of retinal layer thicknesses.

DISCUSSION

DN-NMOSD is characterized by severe retinal damage after ON and attack-independent retinal neurodegeneration. Most of the damage occurs during the first ON episode, which highlights the need for better diagnostic markers in DN-NMOSD to facilitate an earlier diagnosis as well as for effective and early treatments. In this study, people with DN-NMOSD presented with homogeneous clinical and imaging findings potentially suggesting a common retinal pathology in these patients.

Classification of optic neuritis in neuromyelitis optica spectrum disorders (NMOSD) on MRI using CNN with transfer learning and manipulation of pre-processing on augmentation

Neuromyelitis optica spectrum disorder (NMOSD), also known as Devic disease, is an autoimmune central nervous system disorder in humans that commonly causes inflammatory demyelination in the optic nerves and spinal cord. Inflammation in the optic nerves is termed optic neuritis (ON). ON is a common clinical presentation; however, it is not necessarily present in all NMOSD patients. ON in NMOSD can be relapsing and result in severe vision loss. To the best of our knowledge, no study utilises deep learning to classify ON changes on MRI among patients with NMOSD. Therefore, this study aims to deploy eight state-of-the-art CNN models (Inception-v3, Inception-ResNet-v2, ResNet-101, Xception, ShuffleNet, DenseNet-201, MobileNet-v2, and EfficientNet-B0) with transfer learning to classify NMOSD patients with and without chronic ON using optic nerve magnetic resonance imaging. This study also investigated the effects of data augmentation before and after dataset splitting on cropped and whole images. Both quantitative and qualitative assessments (with Grad-Cam) were used to evaluate the performances of the CNN models. The Inception-v3 was identified as the best CNN model for classifying ON among NMOSD patients, with accuracy of 99.5%, sensitivity of 98.9%, specificity of 93.0%, precision of 100%, NPV of 99.0%, and F1-score of 99.4%. This study also demonstrated that the application of augmentation after dataset splitting could avoid information leaking into the testing datasets, hence producing more realistic and reliable results.

MOG Antibody Disease: Nuances in Presentation, Diagnosis, and Management

PURPOSE OF REVIEW

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is a distinct neuroinflammatory condition characterized by attacks of optic neuritis, transverse myelitis, and other demyelinating events. Though it can mimic multiple sclerosis and neuromyelitis optica spectrum disorder, distinct clinical and radiologic features which can discriminate these conditions are now recognized. This review highlights recent advances in our understanding of clinical manifestations, diagnosis, and treatment of MOGAD.

RECENT FINDINGS

Studies have identified subtleties of common clinical attacks and identified more rare phenotypes, including cerebral cortical encephalitis, which have broadened our understanding of the clinicoradiologic spectrum of MOGAD and culminated in the recent publication of proposed diagnostic criteria with a familiar construction to those diagnosing other neuroinflammatory conditions. These criteria, in combination with advances in antibody testing, should simultaneously lead to wider recognition and reduced incidence of misdiagnosis. In addition, recent observational studies have raised new questions about when to treat MOGAD chronically, and with which agent. MOGAD pathophysiology informs some of the relatively unique clinical and radiologic features which have come to define this condition, and similarly has implications for diagnosis and management. Further prospective studies and the first clinical trials of therapeutic options will answer several remaining questions about the peculiarities of this condition.

MOG antibody-associated optic neuritis

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is a demyelinating disorder, distinct from multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). MOGAD most frequently presents with optic neuritis (MOG-ON), often with characteristic clinical and radiological features. Bilateral involvement, disc swelling clinically and radiologically, and longitudinally extensive optic nerve hyperintensity with associated optic perineuritis on MRI are key characteristics that can help distinguish MOG-ON from optic neuritis due to other aetiologies. The detection of serum MOG immunoglobulin G utilising a live cell-based assay in a patient with a compatible clinical phenotype is highly specific for the diagnosis of MOGAD. This review will highlight the key clinical and radiological features which expedite diagnosis, as well as ancillary investigations such as visual fields, visual evoked potentials and cerebrospinal fluid analysis, which may be less discriminatory. Optical coherence tomography can identify optic nerve swelling acutely, and atrophy chronically, and may transpire to have utility as a diagnostic and prognostic biomarker. MOG-ON appears to be largely responsive to corticosteroids, which are often the mainstay of acute management. However, relapses are common in patients in whom follow-up is prolonged, often in the context of early or rapid corticosteroid tapering. Establishing optimal acute therapy, the role of maintenance steroid-sparing immunotherapy for long-term relapse prevention, and identifying predictors of relapsing disease remain key research priorities in MOG-ON.

NMOSD and MOGAD

OBJECTIVE

This article reviews the clinical features, MRI characteristics, diagnosis, and treatment of aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). The main differences between these disorders and multiple sclerosis (MS), the most common demyelinating disease of the central nervous system (CNS), are also highlighted.

LATEST DEVELOPMENTS

The past 20 years have seen important advances in understanding rare demyelinating CNS disorders associated with AQP4 IgG and myelin oligodendrocyte glycoprotein (MOG) IgG. The rapidly expanding repertoire of immunosuppressive agents approved for the treatment of AQP4-NMOSD and emerging as potentially beneficial in MOGAD mandates prompt recognition of these diseases. Most of the recent literature has focused on the identification of clinical and MRI features that help distinguish these diseases from each other and MS, simultaneously highlighting major diagnostic pitfalls that may lead to misdiagnosis. An awareness of the limitations of currently available assays for AQP4 IgG and MOG IgG detection is fundamental for identifying rare false antibody positivity and avoiding inappropriate treatments. For this purpose, diagnostic criteria have been created to help the clinician interpret antibody testing results and recognize the clinical and MRI phenotypes associated with AQP4-NMOSD and MOGAD.

ESSENTIAL POINTS

An awareness of the specific clinical and MRI features associated with AQP4-NMOSD and MOGAD and the limitations of currently available antibody testing assays is crucial for a correct diagnosis and differentiation from MS. The growing availability of effective treatment options will lead to personalized therapies and improved outcomes.

Imaging the brain: diagnosis aided by structural features on neuroimaging studies

The use of neuroimaging allows the ophthalmologist to identify structural lesions in the orbit or along the neuroaxis that allow for more accurate diagnosis and treatment of patients with neuro-ophthalmic diseases. The primary imaging tools include computed tomography (CT) and magnetic resonance imaging (MRI), both of which can be used to evaluate the brain, spinal cord and canal, and orbits. Neurovascular structures, both arterial and venous, also can be imaged in high resolution with modern CT and MR angiography and CT and MR venography. In many cases, invasive procedures such as catheter angiography can be avoided with these studies, and angiography is often reserved for confirmation of vascular lesions combined with endovascular treatment. In this article, we illustrate how the evaluation of patients presenting with neuro-ophthalmic diseases involving the afferent and efferent visual pathways can be optimized with the use of appropriate diagnostic imaging studies. The complementary value of ophthalmic imaging is also demonstrated, and the advantages and disadvantages of both CT and MRI as well as their use in longitudinal patient follow up is demonstrated.

Diagnostic Criteria for Multiple Sclerosis, Neuromyelitis Optica Spectrum Disorders, and Myelin Oligodendrocyte Glycoprotein-immunoglobulin G-associated Disease

The diagnostic workup of multiple sclerosis (MS) has evolved considerably. The 2017 revision of the McDonald criteria shows high sensitivity and accuracy in predicting clinically definite MS in patients with a typical clinically isolated syndrome and allows an earlier MS diagnosis. Neuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein-immunoglobulin G-associated disease (MOGAD) are recognized as separate conditions from MS, with specific diagnostic criteria. New MR imaging markers may improve diagnostic specificity for these conditions, thus reducing the risk of misdiagnosis. This study summarizes the most recent updates regarding the application of MR imaging for the diagnosis of MS, NMOSD, and MOGAD.

Assessing the applicability of the 2023 international MOGAD panel criteria in real-world clinical settings

INTRODUCTION

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently identified demyelinating disorder with a diverse clinical spectrum. Diagnosing MOGAD traditionally relies on clinical judgment, highlighting the necessity for precise diagnostic criteria. Banwell et al. proposed criteria, aiming to refine the diagnostic spectrum. This study evaluates these criteria in a real-life cohort, comparing their performance with clinical judgment and describe the cohort of MOGAD patients.

METHODS

This retrospective study, conducted at Hadassah Medical Center, included 88 patients with MOG-IgG antibodies. Patients with a positive or borderline MOG-IgG antibodies by cell-based assay were included. Demographics, clinical and MRI data were recorded. Cases were divided into definite MOGAD and Non-MOGAD groups as determined by the treating physician. We assessed the sensitivity and specificity of the new criteria in comparison to treating physicians' evaluations. Additionally, we examined clinical differences between the MOGAD and Non-MOGAD groups.

RESULTS

We observed a strong concordance (98%) between the new MOGAD criteria and treating physicians' diagnoses. Clinical disparities between MOGAD and Non-MOGAD groups included lower EDSS scores, normal MRI scans, preserved brain volume, negative OCB results, and distinct relapse patterns. Also, compared to relapsing patients, monophasic MOGAD patients have greater brain volume and a lower age at onset.

CONCLUSION

The study demonstrates robust accuracy of new MOGAD criteria, emphasizing their potential to enhance diagnostic precision. Treatment response integration into the MOGAD diagnosis is crucial, as it could aid in distinguishing MOGAD from other demyelinating disorders. Distinct clinical profiles highlight the importance of informed decisions in managing MOGAD and similar disorders.

Optic Nerve Imaging in Multiple Sclerosis and Related Disorders

Optic neuritis is a common feature in multiple sclerosis and in 2 other autoimmune demyelinating disorders such as aquaporin-4 IgG antibody-associated neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease. Although serologic testing is critical for differentiating these different autoimmune-mediated disorders, MR imaging, which is the preferred imaging modality for assessing the optic nerve, can provide valuable information, suggesting a specific diagnosis and guiding the appropriate serologic testing.

Moving towards a new era for the treatment of neuromyelitis optica spectrum disorders

Neuromyelitis optica spectrum disorders (NMOSD) include a rare group of autoimmune conditions that primarily affect the central nervous system. They are characterized by inflammation and damage to the optic nerves, brain and spinal cord, leading to severe vision impairment, locomotor disability and sphynteric disturbances. In the majority of cases, NMOSD arises due to specific serum immunoglobulin G (IgG) autoantibodies targeting aquaporin 4 (AQP4-IgG), which is the most prevalent water-channel protein of the central nervous system. Early diagnosis and treatment are crucial to manage symptoms and prevent long-term disability in NMOSD patients. NMOSD were previously associated with a poor prognosis. However, recently, a number of randomized controlled trials have demonstrated that biological therapies acting on key elements of NMOSD pathogenesis, such as B cells, interleukin-6 (IL-6) pathway, and complement, have impressive efficacy in preventing the occurrence of clinical relapses. The approval of the initial drugs marks a revolutionary advancement in the treatment of NMOSD patients, significantly transforming therapeutic options and positively impacting their prognosis. In this review, we will provide an updated overview of the key immunopathological, clinical, laboratory, and neuroimaging aspects of NMOSD. Additionally, we will critically examine the latest advancements in NMOSD treatment approaches. Lastly, we will discuss key aspects regarding optimization of treatment strategies and their monitoring.

A burning encephalitis: Fluid-attenuated inversion recovery-hyperintense lesions in Anti-myelin oligodendrocyte glycoprotein-associated encephalitis with seizures in anti-myelin oligodendrocyte glycoprotein-associated encephalitis with seizures-A case report and review of the literature

FLAMES, or fluid-attenuated inversion recovery-hyperintense lesions in anti-myelin oligodendrocyte glycoprotein (anti-myelin oligodendrocyte glycoprotein)-associated encephalitis with seizures, represents a rarely documented syndrome characterized by ambiguous features. Positioned within the spectrum of inflammatory demyelinating diseases of the central nervous system, it is regarded as a distinct subset of myelin oligodendrocyte glycoprotein antibody-associated disease, the latest classification in this domain. Myelin oligodendrocyte glycoprotein antibody-associated disease exhibits a diverse clinical spectrum, spanning from solitary optic neuritis or myelitis to multifocal central nervous system demyelination, manifesting as acute disseminated encephalomyelitis, or cortical encephalitis accompanied by seizures, delineating the fluid-attenuated inversion recovery-hyperintense lesions in anti-myelin oligodendrocyte glycoprotein-associated encephalitis with seizures syndrome. We present a compelling case study of a 30-year-old individual with a history of recurrent seizures initially diagnosed with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes. However, the disease's progression more closely resembled self-resolving cerebral cortical encephalitis linked with myelin oligodendrocyte glycoprotein antibodies. In addition, we undertake a systematic review of literature cases to explore the diagnostic significance of magnetic resonance angiography, fluid-attenuated inversion recovery, and specialized markers such as diffusion-weighted imaging and perfusion in discerning fluid-attenuated inversion recovery-hyperintense lesions in anti-myelin oligodendrocyte glycoprotein-associated encephalitis with seizures syndrome and elucidating its distinctive characteristics.

Uncovering the Diagnostic Challenge of Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease: A Case Study of Acute Bilateral Vision Loss

We discuss a perplexing case of a 51-year-old female with a history of asthma and morbid obesity, presenting with acute bilateral vision loss of unknown etiology. The patient's clinical course was marked by a constellation of symptoms, including blurry vision, eyeball pain, photophobia, headache, nausea, and dizziness, prompting a multidisciplinary approach for diagnostic evaluation. Despite a comprehensive workup and a temporal artery biopsy ruling out large vessel arteritis, the etiology of vision loss remained elusive until myelin oligodendrocyte glycoprotein (MOG) antibody testing returned positive, implicating myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). High-dose corticosteroid therapy was initiated. However, the patient had worsening visual symptoms and was started on plasmapheresis and subsequent administration of Rituximab to prevent relapses, along with a long-term steroid taper regimen. This case underscores the diagnostic challenge of optic neuritis, particularly in MOGAD. It emphasizes the importance of a thorough evaluation and multidisciplinary collaboration.

Trans-Synaptic Degeneration in the Visual Pathway in Patients With Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease

BACKGROUND AND OBJECTIVES

We aimed to assess the presence of retinal neurodegeneration independent of optic neuritis (ON) in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and to investigate the development of trans-synaptic anterograde degeneration in these patients after ON.

METHODS

Cross-sectional, retrospective study of 34 adult patients with MOGAD and 23 healthy controls (HC). Clinical, optical coherence tomography (OCT), and MRI data were collected. Peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell inner plexiform layer (GCIPL) were obtained using Heidelberg Spectralis. FreeSurfer7 was used to obtain the lateral geniculate nucleus (LGN), occipital volume fractions (to total estimated intracranial volume), and occipital cortical thickness. For the anterior visual pathway, the analysis was conducted using eyes, classified based on the history of ON (Eye-ON and Eye-NON) and compared with Eye-HC. The analysis of OCT and brain volumetric measures was conducted comparing MOGAD-ON, MOGAD-NON, and HC groups. The analysis of covariance with a Bonferroni-adjusted post hoc test was used to test differences between groups and linear regression analysis to evaluate OCT/MRI associations; age and sex were considered as covariates.

RESULTS

24 (70.5%) patients had a prior ON. Median pRNFL and GCIPL thickness (um) was significantly reduced in Eye-ON vs EyeNON and HC (pRNFL: 69.4 (17.3), 89.6 (13.7), 98.2 (11.7), p < 0.001; GCIPL: 55.8 (8.7), 67.39 (8.7), 72.6 (4.5), p < 0.001). pRNFL and GCIPL thickness had a negative correlation with the number of ON episodes (p = 0.025 and p = 0.031, respectively). LGN volume fraction was significantly lower in patients with MOGAD-ON than in HC (0.33 (0.05) vs 0.39 (0.04), p = 0.002). The occipital cortical thickness was lower in MOGAD-ON compared with MOGAD-NON and HC (p = 0.010). In patients with MOGAD-ON, pRNFL correlated with LGN volume (p = 0.006), occipital thickness (p = 0.002), and the medial occipital cortex (p = 0.002), but not the lateral occipital lobe.

DISCUSSION

Compared with HC, MOGAD-ON exhibits reduced retinal thickness, primarily influenced by the presence and the number of prior ON episodes. Moreover, MOGAD-ON demonstrates significant atrophy in the retinal, subcortical, and cortical regions of the visual pathway, distinguishing them from MOGAD-NON and HC. These findings suggest that in patients with MOGAD neurodegeneration is tightly correlated with damage to the involved pathway.

Risk of central nervous system demyelinating attack or optic neuritis recurrence after pediatric optic neuritis in Korea

PURPOSE

To investigate the rate of development of symptomatic central nervous system (CNS) demyelinating attacks or recurrent optic neuritis (ON) after the first episode of ON and its risk factors for Korean pediatric patients.

METHODS

This multicenter retrospective cohort study included the patients under 18 years of age (n=132) diagnosed with ON without previous or simultaneous CNS demyelinating diseases. We obtained the clinical data including the results of neuro-ophthalmological examinations, magnetic resonance images (MRIs), antibody assays, and laboratory tests. We investigated the chronological course of demyelinating disease with respect to the occurrence of neurological symptoms and/or signs, and calculated the 5-year cumulative probability of CNS demyelinating disease or ON recurrence.  RESULTS: During the follow-up period (63.1±46.7 months), 18 patients had experienced other CNS demyelinating attacks, and the 5-year cumulative probability was 14.0±3.6%. Involvement of the extraorbital optic nerve or optic chiasm and asymptomatic lesions on the brain or spinal MRI at initial presentation were significant predictors for CNS demyelinating attack after the first ON. The 5-year cumulative probability of CNS demyelinating attack was 44.4 ± 24.8% in the AQP4-IgG group, 26.2±11.4% in the MOG-IgG group, and 8.7±5.9% in the double-negative group (P=0.416). Thirty-two patients had experienced a recurrence of ON, and the 5-year cumulative probability was 24.6±4.0%. In the AQP4-IgG group, the 5-year cumulative probability was 83.3±15.2%, which was significantly higher than in the other groups (P<0.001).

CONCLUSIONS

A careful and multidisciplinary approach including brain/spinal imaging and antibody assay can help predict further demyelinating attacks in pediatric ON patients.

High diagnostic accuracy of T2FLAIR at 3 T in the detection of optic nerve head edema in acute optic neuritis

OBJECTIVES

Optic nerve head edema (ONHE) detected by fundoscopy is observed in one-third of patients presenting optic neuritis (ON). While ONHE is an important semiological feature, the correlation between ONHE and optic nerve head MRI abnormalities (ONHMA), sometimes called "optic nerve head swelling," remains unknown. Our study aimed to assess the diagnostic accuracy of T2 fluid-attenuated inversion recovery (FLAIR) MRI sequence in detecting ONHE in patients with acute ON.

METHODS

In the present single-center study, data were extracted from two prospective cohort studies that consecutively included adults with a first episode of acute ON treated between 2015 and 2020. Two experienced readers blinded to study data independently analyzed imaging. A senior neuroradiologist resolved any discrepancies. The primary judgment criterion of ONHMA was assessed as optic nerve head high signal intensity on gadolinium-enhanced T2FLAIR MRI sequence. Its diagnostic accuracy was evaluated with both the gold standard of ONHE on fundus photography (FP) and peripapillary retinal nerve fiber layer thickening on optic coherence tomography (OCT).

RESULTS

A total of 102 patients were included, providing 110 affected and 94 unaffected optic nerves. Agreement was high between the different modalities: 92% between MRI and FP (k = 0.77, 95% CI: 0.67-0.88) and 93% between MRI and OCT (k = 0.77, 95% CI: 0.67-0.87). MRI sensitivity was 0.84 (95% CI: 0.70-0.93) and specificity was 0.94 (95% CI: 0.89-0.97) when compared with the FP.

CONCLUSION

Optic nerve head high T2FLAIR signal intensity corresponds indeed to the optic nerve head edema diagnosed by the ophthalmologists. MRI is a sensitive tool for detecting ONHE in patients presenting acute ON.

CLINICAL RELEVANCE STATEMENT

In patients with optic neuritis the high T2FLAIR (fluid-attenuated inversion recovery) signal intensity of the optic nerve head corresponds indeed to optic nerve head edema, which is a useful feature in optic neuritis etiological evaluation and treatment.

KEY POINTS

Optic nerve head edema is a prominent clinical feature of acute optic neuritis and is usually diagnosed during dilated or non-dilated eye fundus examination. Agreement was high between magnetic resonance imaging, fundus photography, and optical coherence tomography. Optic nerve head high T2 fluid attenuation inversion recovery signal intensity is a promising detection tool for optic nerve head edema in patients presenting acute optic neuritis.

Updates in NMOSD and MOGAD Diagnosis and Treatment: A Tale of Two Central Nervous System Autoimmune Inflammatory Disorders

Aquaporin-4-IgG positive neuromyelitis optica spectrum disorder (AQP4+NMOSD) and myelin-oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are antibody-associated diseases targeting astrocytes and oligodendrocytes, respectively. Their recognition as distinct entities has led to each having its own diagnostic criteria that require a combination of clinical, serologic, and MRI features. The therapeutic approach to acute attacks in AQP4+NMOSD and MOGAD is similar. There is now class 1 evidence to support attack-prevention medications for AQP4+NMOSD. MOGAD lacks proven treatments although clinical trials are now underway. In this review, we will outline similarities and differences between AQP4+NMOSD and MOGAD in terms of diagnosis and treatment.

Pediatric inflammatory leukoencephalopathies

Acquired demyelinating syndromes (ADS) represent acute neurologic illnesses characterized by deficits persisting for at least 24hours and involving the optic nerve, brain, or spinal cord, associated with regional areas of increased signal on T2-weighted images. In children, ADS may occur as a monophasic illness or as a relapsing condition, such as multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). Almost all young people with MS have a relapsing-remitting course with clinical relapses. Important strides have been made in delineating MS from other ADS subtypes. Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and aquaporin 4-antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) were once considered variants of MS; however, studies in the last decade have established that these are in fact distinct entities. Although there are clinical phenotypic overlaps between MOGAD, AQP4-NMOSD, and MS, cumulative biologic, clinical, and pathologic evidence allows discrimination between these conditions. There has been a rapid increase in the number of available disease-modifying therapies for MS and novel treatment strategies are starting to appear for both MOGAD and AQP4-NMOSD. Importantly, there are a number of both inflammatory and noninflammatory mimics of ADS in children with implications of management for these patients in terms of treatment.

Delimiting MOGAD as a disease entity using translational imaging

The first formal consensus diagnostic criteria for myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) were recently proposed. Yet, the distinction of MOGAD-defining characteristics from characteristics of its important differential diagnoses such as multiple sclerosis (MS) and aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorder (NMOSD) is still obstructed. In preclinical research, MOG antibody-based animal models were used for decades to derive knowledge about MS. In clinical research, people with MOGAD have been combined into cohorts with other diagnoses. Thus, it remains unclear to which extent the generated knowledge is specifically applicable to MOGAD. Translational research can contribute to identifying MOGAD characteristic features by establishing imaging methods and outcome parameters on proven pathophysiological grounds. This article reviews suitable animal models for translational MOGAD research and the current state and prospect of translational imaging in MOGAD.

MRI Signal Intensity Varies Along the Course of the Normal Optic Nerve

BACKGROUND

MRI can help distinguish various causes of optic neuropathy including optic neuritis. Importantly, neuromyelitis optica spectrum disorder (NMOSD) has a propensity to cause enhancement of the prechiasmatic optic nerves. To determine whether the prechiasmatic optic nerve (PC-ON) demonstrates a different intensity from the midorbital optic nerve (MO-ON) on MRI among patients without optic neuropathy.

METHODS

Data were retrospectively obtained from 75 patients who underwent brain MRI for an ocular motor nerve palsy between January 2005 and April 2021. Inclusion criteria were patients aged 18 years or older with visual acuities of at least 20/25 and no evidence of optic neuropathy on neuro-ophthalmic examination. A total of 67 right eyes and 68 left eyes were assessed. A neuroradiologist performed quantitative intensity measurements of the MO-ON and PC-ON on precontrast and postcontrast T1 axial images. Normal-appearing temporalis muscle intensity was also measured and used as a reference to calculate an intensity ratio to calibrate across images.

RESULTS

The mean PC-ON intensity ratio was significantly higher than the MO-ON intensity ratio on both precontrast (19.6%, P < 0.01) and postcontrast images (14.2%, P < 0.01). Age, gender, and laterality did not independently affect measurements.

CONCLUSIONS

The prechiasmatic optic nerve shows brighter intensity ratios on both precontrast and postcontrast T1 images than the midorbital optic nerve among normal optic nerves. Clinicians should recognize this subtle signal discrepancy when assessing patients with presumed optic neuropathy.

Subclinical damage to the contralateral eye in unilateral optic neuritis: A longitudinal study

BACKGROUND

Early detection of subclinical injuries can lead to a correct diagnosis and help control the advancement of the condition. This study aims to investigate the presence of subclinical damage and silent progression to the contralateral eye's visual function and structure in patients experiencing their first episode of unilateral optic neuritis (ON).

METHODS

Fifty patients with first-onset unilateral ON were enrolled in this study. Based on etiology, they were classified as having neuromyelitis optica spectrum disorder-related ON (NMOSD-ON), myelin oligodendrocyte glycoprotein antibody-associated ON (MOG-ON), idiopathic ON (IDON), or multiple sclerosis-related ON (MS-ON). These cases were followed up for one year to determine whether there was any silent progression of visual function and structure in the contralateral non-ON (NON) eye. A gender- and age-matched healthy control (HC) group was included to compare the differences in visual function and structure between the patients with NON eyes and the HC group.

RESULTS

Within two weeks of onset, best-corrected visual acuity (BCVA; P = 0.008), mean deviation (MD) of the visual field (VF) (P = 0.001), and peripapillary retinal nerve fiber layer (pRNFL; P = 0.019) thickness were significantly worse in the NMOSD-NON patients than those in the HC group, while there were no differences in the pRNFL and the ganglion cell-inner plexiform layer (GCIPL) thicknesses and quadrant thicknesses (P > 0.05) of the groups. IDON-NON only showed subclinical damage in VF (P = 0.001) and temporal pRNFL (P = 0.042), while the BCVA, VF, and optic nerve structure (pRNFL, GCIPL) of the MOG-NON patients showed no subclinical damage (P > 0.05). In addition, the one-year follow-up of each NON eye type showed that there was no silent progression in NMOSD-NON, MOG-NON, or IDON-NON. A pairwise comparison of the different types of NON eyes revealed no statistical differences (P > 0.05).

CONCLUSION

Among the patients with unilateral ON, NMOSD-NON and IDON-NON resulted in subclinical damage to the visual function and structure of the contralateral eye within two weeks of onset, whereas MOG-NON did not show any subclinical damage to visual function or structure. Furthermore, these subclinical damages did not show any silent progression during the one-year follow-up period.

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.

MRI to differentiate multiple sclerosis, neuromyelitis optica, and myelin oligodendrocyte glycoprotein antibody disease

Differentiating multiple sclerosis (MS) from other relapsing inflammatory autoimmune diseases of the central nervous system such as neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is crucial in clinical practice. The differential diagnosis may be challenging but making the correct ultimate diagnosis is critical, since prognosis and treatments differ, and inappropriate therapy may promote disability. In the last two decades, significant advances have been made in MS, NMOSD, and MOGAD including new diagnostic criteria with better characterization of typical clinical symptoms and suggestive imaging (magnetic resonance imaging [MRI]) lesions. MRI is invaluable in making the ultimate diagnosis. An increasing amount of new evidence with respect to the specificity of observed lesions as well as the associated dynamic changes in the acute and follow-up phase in each condition has been reported in distinct studies recently published. Additionally, differences in brain (including the optic nerve) and spinal cord lesion patterns between MS, aquaporin4-antibody-positive NMOSD, and MOGAD have been described. We therefore present a narrative review on the most relevant findings in brain, spinal cord, and optic nerve lesions on conventional MRI for distinguishing adult patients with MS from NMOSD and MOGAD in clinical practice. In this context, cortical and central vein sign lesions, brain and spinal cord lesions characteristic of MS, NMOSD, and MOGAD, optic nerve involvement, role of MRI at follow-up, and new proposed diagnostic criteria to differentiate MS from NMOSD and MOGAD were discussed.

Frequency of new asymptomatic MRI lesions during attacks and follow-up of patients with NMOSD in a real-world setting

BACKGROUND

We aimed to assess the frequency of new asymptomatic lesions on brain and spinal imaging (magnetic resonance imaging (MRI)) and their association with subsequent relapses in a large cohort of neuromyelitis optica spectrum disorder (NMOSD) patients in Argentina.

METHODS

We retrospectively reviewed 675 MRI (225 performed during an attack and 450 during the relapse-free period (performed at least 3 months from the last attack)) of NMOSD patients who had at least 2 years of clinical and MRI follow-up since disease onset. Kaplan-Meier (KM) curves were used for depicting time from remission MRI to subsequent relapse.

RESULTS

We included 135 NMOSD patients (64.4% were aquaporin-4-immunoglobulin G (AQP4-IgG)-positive). We found that 26 (19.26%) and 66 (48.88%) of patients experienced at least one new asymptomatic MRI lesion during both the relapse-free period and attacks, respectively. The most frequent asymptomatic MRI lesions were optic nerves followed by short-segment myelitis during the relapse-free period and attacks. KM curves did not show differences in the time taken to develop a new relapse.

CONCLUSION

Our findings showed that new asymptomatic lesions are relatively frequent. However, the presence of new asymptomatic MRI lesions during the relapse-free period and at relapses was not associated with a shorter time to developing subsequent relapses.

Modeling MOG Antibody-Associated Disorder and Neuromyelitis Optica Spectrum Disorder in Animal Models: Visual System Manifestations

BACKGROUND AND OBJECTIVES

Mechanisms of visual impairment in aquaporin 4 antibody (AQP4-IgG) seropositive neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody (MOG-IgG)-associated disorder (MOGAD) are incompletely understood. The respective impact of optic nerve demyelination and primary and secondary retinal neurodegeneration are yet to be investigated in animal models.

METHODS

Active MOG35-55 experimental autoimmune encephalomyelitis (EAE) was induced in C57BL/6Jrj mice, and monoclonal MOG-IgG (8-18C5, murine), recombinant AQP4-IgG (rAb-53, human), or isotype-matched control IgG (Iso-IgG, human) was administered 10 days postimmunization. Mobility impairment was scored daily. Visual acuity by optomotor reflex and ganglion cell complex thickness (GCC, 3 innermost retinal layers) by optical coherence tomography (OCT) were longitudinally assessed. Histopathology of optic nerve and retina was investigated during presymptomatic, acute, and chronic disease phases for immune cells, demyelination, complement deposition, natural killer (NK) cell, AQP4, and astrocyte involvement, retinal ganglion cells (RGCs), and Müller cell activation. Groups were compared by nonparametric tests with a p value <0.05 indicating statistical significance.

RESULTS

Visual acuity decreased from baseline to chronic phase in MOG-IgG (mean ± standard error of the mean: 0.54 ± 0.01 to 0.46 ± 0.02 cycles/degree, p < 0.05) and AQP4-IgG EAE (0.54 ± 0.01 to 0.43 ± 0.02, cycles/degree, p < 0.05). Immune cell infiltration of optic nerves started in presymptomatic AQP4-IgG, but not in MOG-IgG EAE (5.85 ± 2.26 vs 0.13 ± 0.10 macrophages/region of interest [ROI] and 1.88 ± 0.63 vs 0.15 ± 0.06 T cells/ROI, both p < 0.05). Few NK cells, no complement deposition, and stable glial fibrillary acid protein and AQP4 fluorescence intensity characterized all EAE optic nerves. Lower GCC thickness (Spearman correlation coefficient r = -0.44, p < 0.05) and RGC counts (r = -0.47, p < 0.05) correlated with higher mobility impairment. RGCs decreased from presymptomatic to chronic disease phase in MOG-IgG (1,705 ± 51 vs 1,412 ± 45, p < 0.05) and AQP4-IgG EAE (1,758 ± 14 vs 1,526 ± 48, p < 0.01). Müller cell activation was not observed in either model.

DISCUSSION

In a multimodal longitudinal characterization of visual outcome in animal models of MOGAD and NMOSD, differential retinal injury and optic nerve involvement were not conclusively clarified. Yet optic nerve inflammation was earlier in AQP4-IgG-associated pathophysiology. Retinal atrophy determined by GCC thickness (OCT) and RGC counts correlating with mobility impairment in the chronic phase of MOG-IgG and AQP4-IgG EAE may serve as a generalizable marker of neurodegeneration.

Glial autoantibody prevalence in Chinese optic neuritis with onset after age 45: clinical factors for diagnosis

Purpose

As glial autoantibody testing is not yet available in some areas of the world, an alternative approach is to use clinical indicators to predict which subtypes of middle-aged and elderly-onset optic neuritis (ON) have manifested.

Method

This study was a single-center hospital-based retrospective cohort study. Middle-aged and elderly-onset ON patients (age > 45 years) who had experienced the first episode of ON were included in this cohort. Single- and multi-parametric diagnostic factors for middle-aged and elderly-onset myelin oligodendrocyte glycoprotein immunoglobulin-associated ON (MOG-ON) and aquaporin-4 immunoglobulin-related ON (AQP4-ON) were calculated.

Results

From January 2016 to January 2020, there were 81 patients with middle-aged and elderly-onset ON, including 32 (39.5%) AQP4-ON cases, 19 (23.5%) MOG-ON cases, and 30 (37.0%) Seronegative-ON cases. Bilateral involvement (47.4%, P = 0.025) was most common in the MOG-ON group. The presence of other concomitant autoimmune antibodies (65.6%, P = 0.014) and prior neurological history (37.5%, P = 0.001) were more common in the AQP4-ON group. The MOG-ON group had the best follow-up best-corrected visual acuity (BCVA) (89.5% ≤ 1.0 LogMAR, P = 0.001). The most sensitive diagnostic factors for middle-aged and elderly-onset MOG-ON were 'follow-up VA ≤ 0.1 logMAR' (sensitivity 0.89), 'bilateral involvement or follow-up VA ≤ 0.1 logMAR' (sensitivity 0.95), 'bilateral involvement or without neurological history' (sensitivity 1.00), and 'follow-up VA ≤ 0.1 logMAR or without neurological history' (sensitivity 1.00), and the most specific factor was 'bilateral involvement' (specificity 0.81). The most sensitive diagnostic factors for middle-aged and elderly-onset AQP4-ON were 'unilateral involvement' (sensitivity 0.88), 'unilateral involvement or neurological history' (sensitivity 0.91), and 'unilateral involvement or other autoimmune antibodies' (sensitivity 1.00), and the most specific factor was neurological history (specificity 0.98).

Conclusion

Based on our cohort study of middle-aged and elderly-onset ON, MOG-ON is less prevalent than AQP4-ON and Seronegative-ON. Using multiple combined parameters improves the sensitivity and negative predictive value for diagnosing middle-aged and elderly-onset MOG-ON and AQP4-ON. These combined parameters can help physicians identify and treat middle-aged and elderly-onset ON early when glial autoantibody status is not available.

Myelin oligodendrocyte glycoprotein antibody-associated disease as a novel presentation of central nervous system autoimmunity in a pediatric patient with Wiskott-Aldrich syndrome

BACKGROUND

Wiskott-Aldrich syndrome (WAS) is an X-linked primary immunodeficiency caused by mutations in the WAS gene that leads to increased susceptibility to infections, thrombocytopenia, eczema, malignancies, and autoimmunity. Central nervous system (CNS) autoimmune manifestations are uncommon.

CASE PRESENTATION

We describe the case of a five-year-old boy with refractory thrombocytopenia and iron deficiency anemia who developed relapsing bilateral optic neuritis. Myelin oligodendrocyte glycoprotein antibody (MOG-IgG) via serum fluorescence-activated cell sorting assay was positive (titer 1:100), confirming a diagnosis of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). At age six, molecular panel testing for genes associated with primary immunodeficiency identified a missense WAS gene variant. He was subsequently found to have decreased WAS protein expression, consistent with a diagnosis of WAS.

CONCLUSIONS

This case expands the reported spectrum of CNS autoimmunity associated with WAS and may help to inform long-term therapeutic options.

The neuro-ophthalmological manifestations of NMOSD and MOGAD-a comprehensive review

Optic neuritis (ON) is one of the most frequently seen neuro-ophthalmic causes of vision loss worldwide. Typical ON is often idiopathic or seen in patients with multiple sclerosis, which is well described in the landmark clinical trial, the Optic Neuritis Treatment Trial (ONTT). However, since the completion of the ONTT, there has been the discovery of aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) antibodies, which are biomarkers for neuromyelitis optica spectrum disorder (NMOSD) and MOG antibody-associated disease (MOGAD), respectively. These disorders are associated with atypical ON that was not well characterised in the ONTT. The severity, rate of recurrence and overall outcome differs in these two entities requiring prompt and accurate diagnosis and management. This review will summarise the characteristic neuro-ophthalmological signs in NMOSD and MOGAD, serological markers and radiographic findings, as well as acute and long-term therapies used for these disorders.

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

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

Pediatric myelin oligodendrocyte glycoprotein antibody-associated disease in southern China: analysis of 93 cases

Objective

To study the clinical features of children diagnosed with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) in southern China.

Methods

Clinical data of children diagnosed with MOGAD from April 2014 to September 2021 were analyzed.

Results

A total of 93 children (M/F=45/48; median onset age=6.0 y) with MOGAD were involved. Seizures or limb paralysis was the most common onset or course symptom, respectively. The most common lesion locations in brain MRI, orbital MRI, and spinal cord MRI were basal ganglia and subcortical white matter, the orbital segment of the optic nerve, and the cervical segment, respectively. ADEM (58.10%) was the most common clinical phenotype. The relapse rate was 24.7%. Compared with the patients without relapse, relapsed patients had a longer interval from onset to diagnosis (median: 19 days VS 20 days) and higher MOG antibody titer at onset (median: 1:32 VS 1:100) with longer positively persistent (median: 3 months VS 24 months). All patients received IVMP plus IVIG at the acute phase, and 96.8% of patients achieved remission after one to three courses of treatment. MMF, monthly IVIG, and maintaining a low dose of oral prednisone were used alone or in combination as maintenance immunotherapy for relapsed patients and effectively reduced relapse. It transpired 41.9% of patients had neurological sequelae, with movement disorder being the most common. Compared with patients without sequelae, patients with sequelae had higher MOG antibody titer at onset (median: 1:32 VS 1:100) with longer persistence (median: 3 months VS 6 months) and higher disease relapse rate (14.8% VS 38.5%).

Conclusions

Results showed the following about pediatric MOGAD in southern China: the median onset age was 6.0 years, with no obvious sex distribution difference; seizure or limb paralysis, respectively, are the most common onset or course symptom; the lesions of basal ganglia, subcortical white matter, the orbital segment of the optic nerve, and cervical segment were commonly involved in the CNS MRI; ADEM was the most common clinical phenotype; most had a good response to immunotherapy; although the relapse rate was relatively high, MMF, monthly IVIG and a low dose of oral prednisone might effectively reduce relapse; neurological sequelae were common, and possibly associated with MOG antibody status and disease relapse.

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.

Clinical spectrum and prognosis of pathologically confirmed atypical tumefactive demyelinating lesions

To describe the clinical spectrum and prognosis of atypical tumefactive demyelinating lesions (TDLs), which were confirmed by pathology. A total of 11 patients were diagnosed with atypical TDLs confirmed by brain biopsy and surgery between January 2006 and December 2017. The clinical spectrum and prognosis in these patients were analyzed. The patients' ages ranged from 29 to 62 years, with a mean age of 48.9 years; 72.7% were males. The Expanded Disability Status Scale (EDSS) of the patients with first onset was 2.36. Most of the patients started with limb numbness and weakness (45.5%) or alalia (27.2%). The mean time from symptom onset to biopsy or surgery was 12.9 days (3-30 days). Most of the patients had solitary lesions (72.7%), supratentorial lesions (90.9%, particularly predominant in the frontal, temporal, and parietal lobes), moderate edema (63.6%), mild mass effect (54.5%), and patchy lesions (54.5%). Among them, three patients were positive for myelin basic protein (MBP) and one patient was positive for myelin oligodendrocyte glycoprotein (MOG). The patients were followed up for an average of 6.9 years (2-14 years), and recurrent TDLs were observed in 2 patients. Except for the 2 patients who relapsed, only 1 of the 9 patients died; the other 8 patients improved or maintained the status quo (the EDSS scores were lower or unchanged). The patients did not have any serious nervous system injury at onset, and the main presentation included extremity weakness, headache or dizziness, and alalia. The most common form was patchy on MRI enhancement. Cerebrospinal fluid and demyelination test can be an indicator of TDLs, and seizures may be a poor prognostic indicator. Most atypical TDLs have monophasic courses and good outcomes. The effect of neurosurgery alone was good in our group, and the effect of surgery on atypical TDLs can be further studied.

Clinical characteristics and prognosis of optic neuritis in Taiwan - a hospital-based cohort study

BACKGROUND

Optic neuritis (ON) is an inflammatory disease of optic nerve. The distinct etiologies of ON significantly influence its clinical manifestation, neuroimaging findings, and visual outcomes. However, the clinical characteristics might be influenced by the racial differences. The purpose of this study is to investigate the clinical characteristics of various types of ON at a Taiwanese tertiary center.

METHODS

This cohort study analyzed 163 patients who received treatment and continued following-up for ON between 2015 and 2022. We selected patients who had been tested for anti-aquaporin-4 antibody (AQP4-Ab) and anti-myelin oligodendrocyte glycoprotein antibody (MOG-Ab). The participants were classified into four groups on the basis of their etiologies, specifically (1) multiple sclerosis (MS)-related, (2) AQP4-Ab-positive, (3) MOG-Ab-positive, or (4) idiopathic ON. The researchers recorded the patients' clinical characteristics, treatment course, magnetic resonance imaging and optical coherence tomography (OCT) findings, and visual outcomes.

RESULTS

MOG-Ab-positive group had higher percentages of disk swelling and pain with eye movement. Long optic nerve and perineural enhancement are the hallmarks of MOG-Ab-related ON. The ON relapse rate was higher in AQP4-Ab-positive group. Although members of AQP4-Ab-positive group received immediate steroid pulse therapy, these patients experienced the worst visual outcomes. Moreover, a thinner retinal nerve fiber layer (RNFL) was noted in AQP4-Ab-positive group. MS group had a higher incidence of extra-optic nerve lesions. Multivariate regression identified pretreatment visual acuity and RNFL thickness as the important factors affecting visual outcomes.

CONCLUSIONS

This cohort study identified the clinical features of different types of ON. Patients with AQP4-Ab-positive ON had poorer visual outcomes, which may be attributed to multiple relapses and profound nerve damage, as revealed by OCT findings. Patients with MOG-Ab-positive ON displayed long optic nerve enhancement but had more favorable prognoses. Thus, antibody-based classification facilitates treatment and prognosis in ON.