Aseptic meningitis and leptomeningeal enhancement associated with anti-MOG antibodies: A review

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.

Meningeal contrast enhancement in multiple sclerosis: Assessment of field strength, acquisition delay, and clinical relevance

BACKGROUND/PURPOSE

Leptomeningeal enhancement (LME) on post-contrast FLAIR is described as a potential biomarker of meningeal inflammation in multiple sclerosis (MS). Here we report an assessment of the impact of MRI field strength and acquisition timing on meningeal contrast enhancement (MCE).

METHODS

This was a cross-sectional, observational study of 95 participants with MS and 17 healthy controls (HC) subjects. Each participant underwent an MRI of the brain on both a 7 Tesla (7T) and 3 Tesla (3T) MRI scanner. 7T protocols included a FLAIR image before, soon after (Gd+ Early 7T FLAIR), and 23 minutes after gadolinium (Gd+ Delayed 7T FLAIR). 3T protocol included FLAIR before and 21 minutes after gadolinium (Gd+ Delayed 3T FLAIR).

RESULTS

LME was seen in 23.3% of participants with MS on Gd+ Delayed 3T FLAIR, 47.4% on Gd+ Early 7T FLAIR (p = 0.002) and 57.9% on Gd+ Delayed 7T FLAIR (p < 0.001 and p = 0.008, respectively). The count and volume of LME, leptomeningeal and paravascular enhancement (LMPE), and paravascular and dural enhancement (PDE) were all highest for Gd+ Delayed 7T FLAIR and lowest for Gd+ Delayed 3T FLAIR. Non-significant trends were seen for higher proportion, counts, and volumes for LME and PDE in MS compared to HCs. The rate of LMPE was different between MS and HCs on Gd+ Delayed 7T FLAIR (98.9% vs 82.4%, p = 0.003). MS participants with LME on Gd+ Delayed 7T FLAIR were older (47.6 (10.6) years) than those without (42.0 (9.7), p = 0.008).

CONCLUSION

7T MRI and a delay after contrast injection increased sensitivity for all forms of MCE. However, the lack of difference between groups for LME and its association with age calls into question its relevance as a biomarker of meningeal inflammation in MS.

Leptomeningeal Enhancement in Pediatric Anti-Myelin Oligodendrocyte Glycoprotein Antibody Disease, Multiple Sclerosis, and Neuromyelitis Optica Spectrum Disorder

BACKGROUND

Anti-myelin oligodendrocyte glycoprotein (MOG) antibody disease (MOGAD) is a type of acquired demyelinating disease that is distinct from multiple sclerosis (MS) and aquaporin-4 antibody neuromyelitis optica spectrum disorder (AQP4-NMOSD). Leptomeningeal enhancement (LME) has been reported in children and adults with MOGAD, and in adults with MS and AQP4-NMOSD, but less is known about LME in pediatric-onset MS (POMS) and pediatric AQP4-NMOSD. Here we compare the rates of LME in children with MOGAD, POMS, and AQP4-NMOSD.

METHODS

A retrospective chart review was performed in patients with MOGAD, POMS, and AQP4-NMOSD who presented to our institution. Clinical characteristics, imaging features, and relapsing data were included. Descriptive statistics were used, including chi-square or Fischer exact test, to compare proportions. The Benjamini-Hochberg procedure was used to correct for multiple comparisons.

RESULTS

A total of 42 children were included: 16 with POMS, six with AQP4-NMOSD, and 20 with MOGAD. Brain LME was only observed in the MOGAD group (six of 20 = 30%) when compared with zero (0%) POMS and AQP4-NMOSD (P = 0.012). Relapsing disease occurred in nine of 20 (45%), but LME did not associate with relapse.

CONCLUSIONS

LME is only observed in pediatric MOGAD and not in POMS or pediatric AQP4-NMOSD. LME did not predict relapses in MOGAD. Further work is needed to determine the clinical significance of LME in pediatric MOGAD.

Meningeal contrast enhancement in multiple sclerosis: assessment of field strength, acquisition delay, and clinical relevance

Background/Purpose

Leptomeningeal enhancement (LME) on post-contrast FLAIR is described as a potential biomarker of meningeal inflammation in multiple sclerosis (MS). Here we report a comprehensive assessment of the impact of MRI field strength and acquisition timing on meningeal contrast enhancement (MCE).

Methods

This was a cross-sectional, observational study of 95 participants with MS and 17 healthy controls (HC) subjects. Each participant underwent an MRI of the brain on both a 7 Tesla (7T) and 3 Tesla (3T) MRI scanner. 7T protocols included a FLAIR image before, soon after (Gd+ Early 7T FLAIR), and 23 minutes after gadolinium (Gd+ Delayed 7T FLAIR). 3T protocol included FLAIR before and 21 minutes after gadolinium (Gd+ Delayed 3T FLAIR).

Results

LME was seen in 23.3% of participants with MS on Gd+ Delayed 3T FLAIR, 47.4% on Gd+ Early 7T FLAIR (p = 0.002) and 57.9% on Gd+ Delayed 7T FLAIR (p < 0.001 and p = 0.008, respectively). The count and volume of LME, leptomeningeal and paravascular enhancement (LMPE), and paravascular and dural enhancement (PDE) were all highest for Gd+ Delayed 7T FLAIR and lowest for Gd+ Delayed 3T FLAIR. Non-significant trends were seen for higher proportion, counts, and volumes for LME and PDE in MS compared to HCs. The rate of LMPE was different between MS and HCs on Gd+ Delayed 7T FLAIR (98.9% vs 82.4%, p = 0.003). MS participants with LME on Gd+ Delayed 7T FLAIR were older (47.6 (10.6) years) than those without (42.0 (9.7), p = 0.008).

Conclusion

7T MRI and a delay after contrast injection increased sensitivity for all forms of MCE. However, the lack of difference between groups for LME and its association with age calls into question its relevance as a biomarker of meningeal inflammation in MS.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

IMPACT

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

Encephalitis is an Important Phenotype of Myelin Oligodendrocyte Glycoprotein Antibody-Associated Diseases: A Single-Center Cohort Study

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is considered a demyelinating disease of the central nervous system, but an increasing number of encephalitis cases associated with MOG antibodies have been reported recently.

METHODS

This was a single-center, retrospective study. All data for pediatric patients with MOGAD diagnosed at Beijing Children's Hospital from January 2017 to January 2022 were collected. Clinical characteristics and outcomes were analyzed, and treatment responses were compared between the rituximab (RTX) and mycophenolate mofetil (MMF) groups.

RESULTS

A total of 190 patients (age range: 5 months to 16 years; median age: 7.2 years; females: 97) were included in this study. The phenotypes of the first attack included acquired demyelinating syndromes (105 [55%]), encephalitis other than acute disseminated encephalomyelitis (82 [43%]), and isolated meningitis (3 [2%]). After a median follow-up of 30.4 months (interquartile range: 14.8-43.7), 64 (34%) patients had relapses. Fifty-one of the 64 (80%) patients who had relapse received maintenance therapy, including MMF (41), RTX (11), maintenance intravenous immunoglobulin (two), and tocilizumab (two). The annualized relapse rates decreased significantly after treatment in both the RTX and MMF cohorts (P < 0.05); however, there were no significant differences between the two groups (P = 0.56). A total of 178 (94%) patients had complete (175 patients) or almost complete (three patients) recovery (modified Rankin scale [mRS] < 2), and 12 had moderate to severe deficits (mRS ≥ 2).

CONCLUSIONS

The spectrum of pediatric MOGAD is broader than previously reported and includes demyelinating syndromes and encephalitis. Encephalitis is an important initial phenotype observed in pediatric patients with MOGAD.

Cerebral enhancement in MOG antibody-associated disease

INTRODUCTION

Limited data exist on brain MRI enhancement in myelin-oligodendrocyte-glycoprotein (MOG) antibody-associated disease (MOGAD) and differences from aquaporin-4-IgG-positive-neuromyelitis-optica-spectrum-disorder (AQP4+NMOSD), and multiple sclerosis (MS).

METHODS

In this retrospective observational study, we identified 122 Mayo Clinic MOGAD patients (1 January 1996-1 July 2020) with cerebral attacks. We explored enhancement patterns using a discovery set (n=41). We assessed enhancement frequency and Expanded Disability Status Scale scores at nadir and follow-up in the remainder (n=81). Two raters assessed T1-weighted-postgadolinium MRIs (1.5T/3T) for enhancement patterns in MOGAD, AQP4+NMOSD (n=14) and MS (n=26). Inter-rater agreement was assessed. Leptomeningeal enhancement clinical correlates were analysed.

RESULTS

Enhancement occurred in 59/81 (73%) MOGAD cerebral attacks but did not influence outcome. Enhancement was often patchy/heterogeneous in MOGAD (33/59 (56%)), AQP4+NMOSD (9/14 (64%); p=0.57) and MS (16/26 (62%); p=0.63). Leptomeningeal enhancement favoured MOGAD (27/59 (46%)) over AQP4+NMOSD (1/14 (7%); p=0.01) and MS (1/26 (4%); p<0.001) with headache, fever and seizures frequent clinical correlates. Ring enhancement favoured MS (8/26 (31%); p=0.006) over MOGAD (4/59 (7%)). Linear ependymal enhancement was unique to AQP4+NMOSD (2/14 (14%)) and persistent enhancement (>3 months) was rare (0%-8%) across all groups. Inter-rater agreement for enhancement patterns was moderate.

CONCLUSIONS

Enhancement is common with MOGAD cerebral attacks and often has a non-specific patchy appearance and rarely persists beyond 3 months. Leptomeningeal enhancement favours MOGAD over AQP4+NMOSD and MS.

Myelin oligodendrocyte glycoprotein antibody-associated disease in a patient with symptoms of aseptic meningitis who achieved spontaneous remission: A case report and review of the literature

BACKGROUND

A few case reports have described patients with myelin oligodendrocyte glycoprotein antibody (MOG-Ab)-associated demyelinating syndrome who presented with symptoms of aseptic meningitis. All such patients required immunotherapy. We report a patient with MOG-Ab-associated disorder (MOGAD) who presented with symptoms of aseptic meningitis and improved without treatment.

CASE

A 13-year-old girl presented with fever, headache, decreased appetite, and neck stiffness. Cerebrospinal fluid (CSF) analysis revealed pleocytosis and magnetic resonance imaging (MRI) showed leptomeningeal enhancement. The patient was diagnosed with aseptic meningitis at admission. However, there were no signs of recovery 4 days after admission (i.e., 8 days after disease onset). Therefore, we performed extensive investigations to identify the cause of the underlying infection and inflammation. On day 14 after admission, the serum MOG-Ab test performed at admission came back positive (1:128) and she was diagnosed with MOGAD. She was discharged on day 18 after admission, because her symptoms, CSF pleocytosis, and MRI findings had improved. About 6 weeks after discharge, MRI revealed hyperintensity without gadolinium enhancement. However, her serum MOG-Ab test was negative. We did follow-ups for 11 months but found no new neurological symptoms.

DISCUSSION AND CONCLUSION

To the best of our knowledge, this is the first ever report of a pediatric patient with MOGAD experiencing spontaneous remission with no demyelinating symptoms during an extended follow-up period.

Neurosarcoidosis: Diagnostic Challenges and Mimics A Review

PURPOSE OF REVIEW

Neurosarcoidosis is a rare manifestation of sarcoidosis that is challenging to diagnose. Biopsy confirmation of granulomas is not sufficient, as other granulomatous diseases can present similarly. This review is intended to guide the clinician in identifying key conditions to exclude prior to concluding a diagnosis of neurosarcoidosis.

RECENT FINDINGS

Although new biomarkers are being studied, there are no reliable tests for neurosarcoidosis. Advances in serum testing and imaging have improved the diagnosis for key mimics of neurosarcoidosis in certain clinical scenarios, but biopsy remains an important method of differentiation. Key mimics of neurosarcoidosis in all cases include infections (tuberculosis, fungal), autoimmune disease (vasculitis, IgG4-related disease), and lymphoma. As neurosarcoidosis can affect any part of the nervous system, patients should have a unique differential diagnosis tailored to their clinical presentation. Although biopsy can assist with excluding mimics, diagnosis is ultimately clinical.

Leptomeningeal enhancement of myelin oligodendrocyte glycoprotein antibody-associated encephalitis: uncovering novel markers on contrast-enhanced fluid-attenuated inversion recovery images

Background

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is a newly defined autoimmune inflammatory demyelinating central nervous system (CNS) disease characterized by antibodies against MOG. Leptomeningeal enhancement (LME) on contrast-enhanced fluid-attenuated inversion recovery (CE-FLAIR) images has been reported in patients with other diseases and interpreted as a biomarker of inflammation. This study retrospectively analyzed the prevalence and distribution of LME on CE-FLAIR images in children with MOG antibody-associated encephalitis (MOG-E). The corresponding magnetic resonance imaging (MRI) features and clinical manifestations are also presented.

Methods

The brain MRI images (native and CE-FLAIR) and clinical manifestations of 78 children with MOG-E between January 2018 and December 2021 were analyzed. Secondary analyses evaluated the relationship between LME, clinical manifestations, and other MRI measures.

Results

Forty-four children were included, and the median age at the first onset was 70.5 months. The prodromal symptoms were fever, headache, emesis, and blurred vision, which could be progressively accompanied by convulsions, decreased level of consciousness, and dyskinesia. MOG-E showed multiple and asymmetric lesions in the brain by MRI, with varying sizes and blurred edges. These lesions were hyperintense on the T2-weighted and FLAIR images and slightly hypointense or hypointense on the T1-weighted images. The most common sites involved were juxtacortical white matter (81.8%) and cortical gray matter (59.1%). Periventricular/juxtaventricular white matter lesions (18.2%) were relatively rare. On CE-FLAIR images, 24 (54.5%) children showed LME located on the cerebral surface. LME was an early feature of MOG-E (P = 0.002), and cases without LME were more likely to involve the brainstem (P = 0.041).

Conclusion

LME on CE-FLAIR images may be a novel early marker among patients with MOG-E. The inclusion of CE-FLAIR images in MRI protocols for children with suspected MOG-E at an early stage may be useful for the diagnosis of this disease.

Clinical and Radiologic Features Among Children With Myelin Oligodendrocyte Glycoprotein Antibody-Associated Myelitis

BACKGROUND

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) often manifests as optic neuritis, transverse myelitis(TM), and acute disseminated encephalomyelitis. Patients with a TM phenotype are at high risk for neurological sequelae, so recognizing the characteristics of MOG-IgG myelitis is essential for early, accurate diagnosis and treatment.

METHODS

This was a single-center retrospective study. Pediatric MOG antibody-associated disease patients who had clinical myelitis were recruited for this study. Data on clinical and radiologic features and outcomes were retrospectively collected.

RESULTS

Thirty-four patients (age range: 6 months to 13 years; median age, 7 years; female, 16) were enrolled in this study. As one patient had two clinical episodes of myelitis, 35 episodes were included. Isolated transverse myelitis was the initial manifestation in 28 (82%) patients. The most frequent clinical features of MOG-IgG myelitis were weakness and neurogenic bladder, and 80% were better than wheelchair-dependent at the nadir. There was a high presentation of weakness (91%), bowel/bladder dysfunction (63%), and sensory dysfunction (46%), and 80% were better than wheelchair-dependent at the nadir. In addition, seven patients (20%) had radicular pain, and six had flaccid areflexia. Magnetic resonance imaging features were often longitudinally extensive (63%) and prominently involved gray matter (H-sign) (63%), accompanied by leptomeningeal enhancement (4/14.29%) and spinal root enhancement (6/14.43%). At the final follow-up (median, 28 months; range, 8-109 months), 10 patients (29%) had developed one or more relapses, spinal cord lesions resolved entirely in 11 of 22 children (50%), and none had appreciable spinal cord atrophy. At the final follow-up, most patients had favorable outcomes, with median (interquartile range) Expanded Disability Status Scale scores of 0 (range, 0-2), four patients (12%) had sphincter dysfunction, and one patient had gait problems.

CONCLUSIONS

Pediatric MOG-IgG myelitis clinically presents with weakness and bowel and bladder dysfunctions. Prominent involvement of the gray matter, leptomeningeal enhancement, and spinal root enhancement are common in pediatric MOG-IgG myelitis.

MOG Antibody-Associated Disease and Thymic Hyperplasia: From the National Multiple Sclerosis Society Case Conference Proceedings

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently described CNS inflammatory disorder that may manifest with optic neuritis, myelitis, seizures, and/or acute disseminated encephalomyelitis. While MOG-specific antibodies in patients with MOGAD are IgG1, a T-cell-dependent antibody isotype, immunologic mechanisms of this disease are not fully understood. Thymic hyperplasia can be associated with certain autoimmune diseases. In this report we describe a case of MOGAD associated with thymic hyperplasia in a young adult.

Anti-MOG Antibody-Associated Unilateral Cortical Encephalitis with Bilateral Meningeal Involvement: A Case Report

A 27-year-old Han Chinese woman presented with fever, headache, lethargy, and difficulty in expression. Magnetic resonance imaging (MRI) detected extensive hyperintensity of the left-sided frontoparietal, temporal, occipital, and insular cortices via fluid-attenuated inversion recovery (FLAIR) imaging. Post-contrast MRI revealed linear enhancement in the frontoparietal, temporal, and occipital sulci bilaterally. The detection of anti-myelin oligodendrocyte glycoprotein (MOG) was positive in the cerebrospinal fluid (CSF) and serum. The patient was diagnosed with anti-MOG antibody-associated unilateral cortical encephalitis with bilateral meningeal involvement. The patient received low doses of intravenous dexamethasone followed by oral prednisone, which was tapered until withdrawal. The treatment significantly improved the patient's symptoms. A one-month follow-up showed that the patient gradually resumed her normal lifestyle. No further relapse was recorded after a one-year follow-up. MRI performed almost a year after the initial symptom onset showed that the FLAIR signal had decreased in the left insular lobe, and the abnormal cortical signal of the FLAIR in the original left frontotemporal occipital lobe had disappeared. Thus, we report a rare case of anti-MOG antibody encephalitis (unilateral cortical encephalitis with bilateral meningeal involvement) in an adult patient. This study provides a reference for the clinical diagnosis and treatment of MOG antibody-associated unilateral cortical encephalitis.

Volumetric brain changes in MOGAD: A cross-sectional and longitudinal comparative analysis

BACKGROUND

Relatively little is known about how global and regional brain volumes changes in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) compare with Multiple Sclerosis (MS), Neuromyelitis optica spectrum disorder (NMOSD), and healthy controls (HC).

OBJECTIVE

To compare global and regional brain volumes in MOGAD, MS, NMOSD, and HC cross-sectionally as well as longitudinally in a subset of patients.

METHODS

We retrospectively reviewed all adult MOGAD and NMOSD patients with brain MRI performed in stable remission and compared them with MS patients and HC. Volumetric parameters were assessed using the FDA-approved icobrain software. adjusted for age and sex.

RESULTS

Twenty-four MOGAD, 47 NMOSD, 40 MS patients, and 37 HC were included in the cross-sectional analyses. Relative to HC, the age-adjusted whole brain (WB) volume was significantly lower in patients with MOGAD (p=0.0002), NMOSD (p=0.042), and MS (p=0.01). Longitudinal analysis of a subset of 8 MOGAD, 22 NMOSD, and 34 MS patients showed a reduction in the WB and cortical gray matter (CGM) volumes over time in all three disease groups, without statistically significant differences between groups. The MOGAD group had a greater loss of thalamic volume compared to MS (p=0.028) and NMOSD (p=0.023) and a greater loss of hippocampal volumes compared to MS (p=0.007).

CONCLUSIONS

Age-adjusted WB volume loss was evident in all neuroinflammatory conditions relative to HC in cross-sectional comparisons. In longitudinal analyses, MOGAD patients had a higher thalamic atrophy rate relative to MS and NMOSD, and a higher hippocampal atrophy rate relative to MS. Larger studies are needed to validate these findings and to investigate their clinical implications.

Meningo-cortical manifestations of myelin oligodendrocyte glycoprotein antibody-associated disease: Review of a novel clinico-radiographic spectrum

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an inflammatory demyelinating disease that is distinct from multiple sclerosis. Initial manifestations of MOGAD that were reported in the literature included optic neuritis, myelitis, brainstem demyelination and encephalitis, with emphasis placed on acute disseminated encephalomyelitis (ADEM) as the primary encephalitic presentation. In 2017, however, Ogawa et al. described four patients with seizures, unilateral cortical hyperintensities on brain magnetic resonance imaging T2-fluid-attenuated inversion recovery sequences, and anti-MOG positivity, indicating a potentially novel form of encephalitis in MOGAD. In 2019, we systematically reviewed the literature to better characterize this unique syndrome, which we referred to as unilateral cortical FLAIR-hyperintense Lesions in Anti-MOG-associated Encephalitis with Seizures (FLAMES). Subsequently, anti-MOG positivity in patients with a variety of cortical and meningeal disease presentations has been reported, indicating a broader spectrum of meningo-cortical manifestations in MOGAD that we review herein.