Anti-myelin oligodendrocyte glycoprotein antibodies: Magnetic resonance imaging findings in a case series and a literature review

Acute Hemorrhagic Encephalomyelitis in the Context of MOG Antibody-Associated Disease. Comment on Chen et al. Rapid Progressive Fatal Acute Hemorrhagic Encephalomyelitis. Diagnostics 2023, 13, 2481

The study by Chen et al. of a 56-year-old man diagnosed with acute hemorrhagic encephalomyelitis (AHEM) had a significant impact on us. The authors provided a comprehensive account of their diagnostic journey and emphasized the need to differentiate myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) from AHEM. However, recent research suggests that AHEM may not be an isolated entity, but rather a phenotype within MOGAD. The patient's clinical presentation included MRI brain lesions characteristic of MOGAD in addition to hemorrhagic abnormalities. These findings raise the possibility that AHEM in this case represents a MOGAD phenotype. In conclusion, it is important to recognize the potential association between AHEM and MOGAD, especially when distinct MOGAD brain MRI patterns are present, as in this case.

Nontraumatic orbital emergencies: a pictorial essay - CT and MRI features for an imaging findings-based approach

Orbital imaging plays a pivotal role in each hospital with an Ophthalmological Emergency Department. Unenhanced orbital computed tomography (CT) usually represents the first-line tool for the assessment of nontraumatic orbital emergencies, thanks to its quick execution, wide availability, high resolution, and availability of multiplanar reformats/reconstructions. Magnetic resonance imaging (MRI) is an essential tool that allows characterization and a better understanding of the anatomical involvement of different disorders due to its excellent contrast resolution and ability to study the visual pathways, even if, unfortunately, it is not always available in the emergency setting. It represents the first imaging choice in pediatric patients, due to the absence of ionizing radiation. When available, CT and MRI are often used together to diagnose, assess the extent, and provide treatment plans for various orbital nontraumatic emergencies, including infective, inflammatory, vascular, and neoplastic diseases. Familiarity with the imaging appearances of these disorders helps the radiologists to establish the correct diagnosis in the emergency setting, which contributes to timely clinical management. This pictorial essay provides a description of the clinical presentation and imaging findings of nontraumatic orbital emergencies.

Clinical characteristics of optic neuritis phenotypes in a 3-year follow-up Chinese cohort

To evaluate the clinical characteristics of optic neuritis (ON) with different phenotypes. This prospective study recruited patients with new-onset ON between January 2015 and March 2017 who were followed-up for 3 years. They were divided into the myelin oligodendrocyte glycoprotein-seropositive (MOG-ON), aquaporin-4-seropositive (AQP4-ON), and double-seronegative (seronegative-ON) groups, and their clinical characteristics and imaging findings were evaluated and compared. Two-hundred-eighty patients (405 eyes) were included (MOG-ON: n = 57, 20.4%; AQP4-ON: n = 98, 35.0%; seronegative-ON: n = 125, 44.6%). The proportion of eyes with best-corrected visual acuity > 20/25 at the 3-year follow-up was similar between the MOG-ON and seronegative-ON groups; the proportion in both groups was higher than that in the AQP4-ON group (p < 0.001). Relapse rates were higher in the MOG-ON and AQP4-ON groups than in the seronegative-ON group (p < 0.001). Average retinal nerve fiber layer (RNFL) thickness at 3 years was similar between the MOG-ON and AQP4-ON groups (63.41 ± 13.39 and 59.40 ± 11.46 μm, p = 0.476) but both were thinner than the seronegative-ON group (74.06 ± 11.14 μm, p < 0.001). Macular ganglion cell-inner plexiform layer (GCIPL) revealed the same pattern. Despite RNFL and GCIPL thinning, the MOG-ON group’s outcome was as favorable as that of the seronegative-ON group, whereas the AQP4-ON group showed unsatisfactory results.

Radiomic analysis of the optic nerve at the first episode of acute optic neuritis: an indicator of optic nerve pathology and a predictor of visual recovery?

OBJECTIVE

Retinal nerve fiber layer thickness (RNFL) is a biomarker of neuroaxonal loss and index of visual function in multiple sclerosis (MS). We aimed to assess the correlation between radiomic features and RNFL, visual acuity (VA) at patients' presentation, visual outcome (VO), and clinical diagnosis.

METHODS

We reviewed imaging and clinical data of 25 patients with a first episode of optic neuritis (ON) (14 females, 11 males; 5 bilateral ON; 7 left ON; 13 right ON). All patients underwent a complete ophthalmological assessment, including visual acuity and RNFL, neurological evaluation, orbits MRI. Segmentation of the optic nerves was performed through 3D slicer open software to get radiomics analysis. All patients underwent a complete neuro-ophthalmological follow-up at 6 months to assess the VO, classified as: complete recovery, partial recovery, deficit persistence/relapse, or visual worsening and were diagnosed as MS or clinically isolated syndrome.

RESULTS

We observed significant correlations between radiomic features and RNFL and between radiomic features and VA. Regression model analysis identified 1 radiomic feature with significant association with VO (Gray Level non-uniformity Normalized, p = 0.004) and 6 radiomic features with significant correlation with diagnosis (High Gray Level Zone Emphasis, p < 0.001; Entropy, p < 0.001, for T1 segmentation; Mean Absolute Deviation, p < 0.001; Coarseness < 0.001; Small Area Low Gray Level Emphasis, p < 0.001; Contrast, p = 0.008, for STIR segmentation).

CONCLUSION

Orbits MRI analysis at the first episode of ON has the potential to assess the visual function and VO in ON patients, and predict MS development.

Cognitive impairment in NMOSD-More questions than answers

INTRODUCTION

Neuromyelitis optica spectrum disorder (NMOSD) is a type of central nervous system antibody-mediated disease which affects mainly optic nerves and spinal cord, but may also present with acute brainstem syndrome, acute diencephalic syndrome, and cerebral syndrome with typical brain lesions. One of the most disabling symptoms, diagnosed in 29%-67% of cases, is cognitive dysfunction, with such processes as memory, processing speed, executive function, attention, and verbal fluency being predominantly affected. However, description of cognition in NMOSD patients is still a relatively new area of research.

METHODS

A systematic MEDLINE search was performed to retrieve all studies that investigated cognitive impairment and its clinical correlates in patients with NMOSD.

RESULTS

We summarize the current knowledge on cognitive impairment profile, neuropsychological tests used to examine NMOSD patients, clinical and demographical variables affecting cognition, and magnetic resonance imaging correlates. We provide a comparison of cognitive profile of patients with multiple sclerosis and NMOSD.

CONCLUSION

Patients with NMOSD are at significant risk of cognitive deficits. However, the knowledge of cognitive symptoms in NMOSD and potential modifying interventions is still scarce. Further accumulation of clinical data may facilitate effective therapeutic interventions.

Anti-myelin oligodendrocyte glycoprotein antibody-positive coursing with optic neuritis: Imaging and clinical implications

A 9-year-old boy was admitted to our institution with acute onset of bilateral blurry vision. Physical examination revealed bilateral papilledema. Cerebrospinal fluid analysis and comprehensive metabolic panel were normal. Magnetic resonance imaging (MRI) of the brain showed extensive bilateral optic nerve inflammation with post-contrast gadolinium enhancement on T1-weighted sequence. The involvement was limited to the anterior segments of the optic nerves sparing chiasma and optic tracts. Anti-aquaporin-4 antibody (AQP4) was negative while anti-myelin oligodendrocyte glycoprotein antibody (MOG) was positive. After intravenous methylprednisolone, his vision dramatically improved. The patient was discharged with only mildly impaired visual acuity, 2 weeks after admission. Follow-up brain MRI and MOG assay after 3 months were within normal limits.

Myelin Oligodendrocyte Glycoprotein (MOG)-IgG Associated Demyelinating Disease: Our Experience with this Distinct Syndrome

Background

Discovery of serum myelin oligodendrocyte glycoprotein (MOG) antibody testing in demyelination segregated MOG-IgG disease from AQ-4-IgG positive NMOSD.

Aims

To study clinico-radiological manifestations, pattern of laboratory and electrophysiological investigations and response to treatment through follow up in MOG-IgG positive patients.

Method

Retrospective data of MOG-IgG positive patients was collected. Demographics, clinical manifestations at onset and at follow up and relapses, anti AQ-4-IgG status, imaging and all investigations were performed, treatment of relapses and further immunomodulatory therapy were captured.

Results

In our 30 patients, F: M ratio was 2.75:1 and adult: child ratio 4:1. Relapses at presentation were optic neuritis {ON}(60%), longitudinally extensive transverse myelitis {LETM}(20%), acute disseminated encephalomyelitis {ADEM}(13.4%), simultaneous ON with myelitis (3.3%) and diencephalic Syndrome (3.3%). Salient MRI features were ADEM-like lesions, middle cerebellar peduncle fluffy infiltrates, thalamic and pontine lesions and longitudinally extensive ON {LEON} as well as non-LEON. Totally, 50% patients had a relapsing course. Plasma exchange and intravenous immunoglobulin worked in patients who showed a poor response to intravenous methylprednisolone. Prednisolone, Azathioprine, Mycophenolate and Rituximab were effective attack preventing agents.

Conclusions

MOG-IgG related manifestations in our cohort were monophasic/recurrent/simultaneous ON, myelitis, recurrent ADEM, brainstem encephalitis and diencephalic Syndrome. MRI features suggestive of MOG-IgG disease were confluent ADEM-like lesions, middle cerebellar peduncle fluffy lesions, LETM, LEON and non-LEON. Where indicated, patients need to go on immunomodulation as it has a relapsing course and can accumulate significant disability. Because of its unique manifestations, it needs to be considered as a distinct entity. To the best of our knowledge, this is the largest series of MOG-IgG disease reported from India.

Quantitative brain lesion distribution may distinguish MOG-ab and AQP4-ab neuromyelitis optica spectrum disorders

OBJECTIVES

Antibodies to myelin oligodendrocyte glycoprotein (MOG-ab) and antibodies to aquaporin-4 (AQP4-ab) have been suggested to play roles in commonly separated subsets of patients with neuromyelitis optica spectrum disorder (NMOSD) phenotypes. The aim of this study is to quantitatively delineate and compare the brain lesion distributions of AQP4-ab-positive and MOG-ab-positive patients.

METHODS

Fifty-seven and twenty-eight clinical MRI scans were collected from fifty-two AQP4-ab-positive and twenty-four MOG-ab-positive patients, respectively. T2 lesions were segmented manually on each axial FLAIR image. Probabilistic lesion distribution maps were created for each group after spatial normalization. Lobe-wise and voxel-wise quantitative comparisons of the two distributions were performed. A classification model based on the lesion distribution features was constructed to differentiate the two patient groups.

RESULTS

Infratentorial and supratentorial brain lesions were found in both AQP4-ab-positive and MOG-ab-positive patients, with large inter-group overlap mainly in deep white matter (WM). In comparison with those in the AQP4 group, the brain lesions of the MOG-ab-positive patients had a larger size, dispersed distribution, and higher probabilities in the cerebellum, pons, midbrain, and GM and juxtacortical WM in temporal, sublobar, frontal, and parietal lobes. The area under the receiver operating characteristic curve of the lesion-distribution-based classification model was 0.951.

CONCLUSIONS

MOG-ab-positive and AQP4-ab-positive groups showed similar but quantitatively different brain lesion distributions. These results may help clinicians in considering MOG versus AQP4 in initial diagnosis, and add rationale for sending corresponding serologic testing.

KEY POINTS

• Brain lesion distributions of AQP-ab-positive and MOG-ab-positive NMOSD patients • Larger size, dispersed distribution, higher lesion probabilities in the cerebellum, pons, midbrain, and GM and juxtacortical WM in the MOG group • The lesion-distribution-based classification model differentiates the two groups with AUC = 0.951.

Clinical characteristics of myelin oligodendrocyte glycoprotein seropositive optic neuritis: a cohort study in Shanghai, China

Qualitative and quantitative visual outcomes of Asian optic neuritis (ON) patients with seropositive myelin oligodendrocyte glycoprotein (MOG) antibodies remain unknown. We retrospectively evaluated a cohort of new-onset ON patients in Shanghai, China between January 2015 and December 2016. Serum MOG and aquaporin-4 (AQP4) antibodies were detected using cell-based assays, and patients were followed-up for at least 6 months. The clinical characteristics and optical coherence tomography (OCT) results were evaluated in the MOG-seropositive optic neuritis (MOG-ON), AQP4-seropositive (AQP4-ON), and double seronegative (Seronegative-ON) patients. Best-corrected visual acuity (BCVA) and peripapillary retinal nerve fiber layer (RNFL) thickness after 6 months of follow-up were compared. Among MOG-ON (n = 49, 64 eyes), AQP4-ON (n = 76, 102 eyes), and Seronegative-ON patients (n = 100, 116 eyes), the percentages of BCVAs better than 0.8 (20/25) at the 6-month visit were 67.19, 19.60, and 72.41%, respectively, which showed no statistical difference between MOG-ON and Seronegative-ON patients (p = 0.198), but were better than the AQP4-ON patients (P = 0.001). The average peripapillary RNFLs measured 6 months after the attack were 58.03 ± 8.73, 64.34 ± 12.88, and 78.12 ± 13.34 μm for the MOG-ON, AQP4-ON, and Seronegative-ON patients, respectively. There was no statistical difference between MOG-ON and AQP4-ON patients (P = 0.089), but both were thinner than Seronegative-ON patients (P = 0.001). The visual acuity in MOG-ON patients was as good as Seronegative-ON patients, whereas the RNFL of the optic nerve head showed a significant thinning as in the AQP4-ON patients.