Tumefactive Demyelination in MOG Ab-Associated Disease, Multiple Sclerosis, and AQP-4-IgG-Positive Neuromyelitis Optica Spectrum Disorder

Paraneoplastic Tumefactive Demyelination With Underlying Anaplastic Thyroid Cancer: A Case Report and Review of the Literature

We present a case of paraneoplastic tumefactive demyelination in a 55-year-old female with an underlying anaplastic thyroid carcinoma (ATC), alongside a review of the literature on all cases of tumefactive demyelination associated with non-CNS neoplasia. In the presented case the patient developed a right-sided subacute sensorimotor hemiparesis. The initial cerebral MRI revealed a bilateral frontoparietal tumefactive mass lesion with marked gadolinium uptake and mass effect. Cerebrospinal fluid revealed CSF-specific oligoclonal bands type III, with negative cell count, protein and pathogen testing. Brain biopsy indicated demyelination and T-cell infiltrates and foamy macrophages. A body CT revealed an anaplastic thyroid carcinoma. Despite steroids, plasma exchange, rituximab, and cancer treatment, the patient died due to clinical fluctuation and cancer progression. In addition to our case 9 cases of tumefactive demyelinating have been reported in patients with newly diagnosed extracranial neoplasia, most commonly seminoma germ cell tumour (7/10). 8/10 (80%) of patients were male, with mean age at diagnosis was 52.9 years 95% C.I. [43.8, 62.0]. 5/10 patients presented with sensorimotor hemiparesis and/or confusion/neurocognitive deficits. 4/10 with visual deficits and 2/10 with aphasia. In all cases neoplasia was diagnosed simultaneously or after neurological manifestations. All cases presented initially as solitary lesions. A malignancy specific-treatment as well as steroid treatment in different regiments were applied. In addition in 2/10 plasmapheresis was implemented and 1/10 patients received intravenous immunoglobulins. In the majority of cases including the presented case partial neurological improvement was documented whereas malignancy usually progressed. To our knowledge, this is the first report of paraneoplastic tumefactive demyelination associated with an ATC highlighting the importance of a thorough workup in these patients. This is the first reported case of paraneoplastic tumefactive demyelination associated with ATC, underscoring the necessity of a comprehensive diagnostic approach in similar patients.

Predicting intrathecal immunoglobulin synthesis in the ICU: a comparative study of IgG-based indexes

BACKGROUND

Central nervous system autoimmune diseases (CNS-AD) such as autoimmune encephalitis and myelitis are severe conditions, often requiring ICU admission. Early diagnosis is crucial but difficult, as initial steps facing sub-acute neurological disorders try to exclude non-immune causes such as stroke or infections through MRI and multiplex PCR assays. Current acute-phase autoimmune identifiers are lacking, with definitive diagnosis hinging on delayed tests like antibody detection or intrathecal immunoglobulin synthesis (ISI) identification via iso-electric focalization (IEF). This study evaluates surrogate markers, such as the IgG quotient (QIgG), IgG index, and Reiber's formula, which are rapidly obtainable, to quickly predict ISI in the ICU setting, aiming to expedite treatment initiation.

METHODS

We screened all neuro-ICU admissions from 2008 to 2022 in our center, including patients who underwent a lumbar puncture (LP) and were tested for ISI via IEF. We excluded those lacking concomitant CSF/serum albumin and IgG data. Patients were categorized by final diagnosis as "CNS-AD" or "other", and whether ISI was present. We calculated QIgG, IgG index, and Reiber's formula, comparing their performance to IEF for sensitivity (Se) and specificity (Sp).

RESULTS

ISI was detected in 35% of patients (93/266). In the "CNS-AD" group, 54% were ISI-positive, while 21% of patients in the "Other" group also showed ISI. Among the three indexes, only the IgG index showed strong specificity (95%) but moderate sensitivity (56%). QIgG and Reiber's formula had similar sensitivity (67% and 66%) but lower specificity (41% for both). Multivariable analysis identified age < 50 years (OR 2.5 [95% CI 1.3-4.7]) and an IgG index > 0.7 (OR 14.2 [95% CI 6.6-32.0]) as factors independently associated with ISI positivity. Using the Youden index and likelihood ratio, we recalibrated thresholds to improve performance. A "grey zone" was defined for the IgG index (0.67-0.80), below which ISI was unlikely and above which it was considered probable.

CONCLUSION

While the IgG index's low sensitivity limits its standalone diagnostic use, its high specificity makes this index a good one when positive, to weigh in the decision-making process to treat or not a patient with suspected CNS-AD, while awaiting IEF results, which can take days or even weeks in some centers.

Anti-neutrophil cytoplasmic antibody-associated central nervous system vasculitis mimicking brain tumor: A case report

Here, we report a case of antineutrophil cytoplasmic antibody (ANCA)-associated central nervous system (CNS) vasculitis that mimicked a brain tumor. The patient presented with progressive right upper arm weakness. Brain magnetic resonance imaging (MRI) revealed large tumor-like lesions in the left frontal and parietal lobes, with patchy and irregular enhancement with gadolinium and edema. Based on the clinical course and radiological findings, a brain tumor was suspected, and stereotactic brain biopsy was performed. Brain histopathology revealed necrotic tissue and lymphocyte infiltration around small vessels and blood vessel walls. Although the patient's clinical course and pathological findings suggested primary angiitis of CNS (PACNS), double staining for myeloperoxidase (MPO) and CD31 (a neutrophil marker) revealed infiltration of MPO-positive neutrophils in the blood vessel walls. Therefore, we diagnosed the patient with ANCA-associated CNS vasculitis. Because CNS vasculitis, including PACNS, presents nonspecific clinical findings and can depict brain tumor-like MRI findings, CNS vasculitis should be carefully differentiated from brain tumors. Additionally, double staining for MPO and CD31 might be useful for evaluating the pathogenesis of CNS vasculitis.

Quantitative proteomics analysis of cerebrospinal fluid reveals putative protein biomarkers for canine non-infectious meningoencephalomyelitis

Accurate ante-mortem diagnosis of non-infectious meningoencephalomyelitis (NIME) in dogs is challenging due to the similarity of clinical presentations, imaging findings, and cerebrospinal fluid (CSF) analysis results with other diseases. This study aimed to apply state-of-the-art quantitative proteomic technology to identify novel biomarkers for NIME. Serum and CSF samples from 11 dogs were included, with the control group consisting of patients presenting with intervertebral disc disease (IVDD, n = 6) and the study group consisting of dogs suffering from NIME (n = 5). Mass spectrometry-based quantitative proteomics revealed a set of 36 proteins with significant differential abundance in CSF samples. Up-regulated proteins in NIME CSF included immunoglobulins, inter-alpha-trypsin inhibitor heavy chain 2, acid sphingomyelinase-like phosphodiesterase, and chitinase 3-like protein 1, all associated with immune response and inflammation. Conversely, significantly down-regulated proteins included neural cell adhesion molecule, contactin-1, and procollagen C-endopeptidase enhancer, which are involved in neurodevelopment and synaptic plasticity. No differences in serum profiles were observed among the groups. This study identified a panel of CSF protein biomarker candidates for NIME and provided new insights into the pathogenesis of the disease, suggesting that neuronal dysfunction and immune dysregulation may be involved.

MRI management of NMOSD and MOGAD: Proposals from the French Expert Group NOMADMUS

BACKGROUND

Currently, there are no available recommendations or guidelines on how to perform MRI monitoring in the management of neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). The issue is to determine a valuable MRI monitoring protocol to be applied in the management of NMOSD and MOGAD, as previously proposed for the monitoring of multiple sclerosis.

OBJECTIVES

The objectives of this work are to establish proposals for a standardized and feasible MRI acquisition protocol, and to propose control time points for systematic MRI monitoring in the management of NMOSD and MOGAD.

METHODS

A steering committee composed of 7 neurologists and 5 neuroradiologists, experts in NMOSD and MOGAD from the French group NOMADMUS, defined 8 proposals based on their expertise and a review from the literature. These proposals were then submitted to a Rating Group composed of French NMOSD / MOGAD experts.

RESULTS

In the management of NMOSD and MOGAD, a consensus has been reached to perform systematic MRI of the brain, optic nerve and spinal cord, including cauda equina nerve roots, at the time of diagnosis, both without and after gadolinium administration. Moreover, it has been agreed to perform a systematic MRI scan 6 months after diagnosis, focusing on the area of interest, both without and after gadolinium administration. For long-term follow-up of NMOSD and MOGAD, and in the absence of clinical activity, it has been agreed to perform gadolinium-free MRI of the brain (+/- optic nerves) and spinal cord, every 36 months. Ideally, these MRI scans should be performed on the same MRI system, preferably a 3T MRI system for brain and optic nerve MRI, and at least a 1.5T MRI system for spinal cord MRI.

CONCLUSIONS

This expert consensus approach provides physicians with proposals for the MRI management of NMOSD and MOGAD.

The magnetic resonance imaging (MRI) features of intracranial lesions in myelin oligodendrocyte glycoprotein-immunoglobulin G-associated disease (MOGAD)

AIM

This study aimed to summarise and analyse the magnetic resonance imaging (MRI) characteristics of patients with myelin oligodendrocyte glycoprotein-immunoglobulin G-associated disease (MOGAD), and to enhance the accuracy of disease diagnosis and advance scientific research.

MATERIALS AND METHODS

A retrospective collection of clinical data from 103 patients with MOGAD was conducted. The distribution and signal characteristics of intracranial lesions on MRI were analysed. Further subgroup statistical analysis based on age was performed to explore differences in lesion locations among different subgroups. Statistical comparisons were made using the χ2 test or Fisher's exact test, with a significance level of P < 0.05 considered statistically significant.

RESULTS

MRI revealed variable lesion morphologies in patients with MOGAD. Lesions were predominantly located in the cerebral deep white matter (47.6%), subcortical white matter (38.8%), and cortex (38.8%) of the supratentorial region, as well as in the brainstem (35.9%) of the infratentorial region. Notably, there was a significantly higher proportion of juvenile patients with thalamic involvement than adult patients (P = 0.013). Juvenile patients were more likely to have lesions involving both the thalamus and cerebral cortex (P = 0.040), thalamus and deep white matter (P = 0.026), or thalamus and brainstem (P = 0.014). Conversely, lesions involving both the corpus callosum and subcortical white matter were more frequently observed in adult patients, with statistically significant differences (P = 0.046). Contrast-enhanced MRI showed mild enhancement in some lesions, with a half of cases exhibiting leptomeningeal enhancement. One rare case presented extensive thickening and enhancement of the falx cerebri.

CONCLUSION

The distribution of intracranial lesions on MRI exhibits distinct characteristics. The differences in the spatial distribution of intracranial lesions between juvenile and adult patients suggest that MOGAD may represent a heterogeneous disease spectrum that varies with age.

Precision neurology

Over the past several decades, high-resolution brain imaging, blood and cerebrospinal fluid analyses, and other advanced technologies have changed diagnosis from an exercise depending primarily on the history and physical examination to a computer- and online resource-aided process that relies on larger and larger quantities of data. In addition, randomized controlled trials (RCT) at a population level have led to many new drugs and devices to treat neurological disease, including disease-modifying therapies. We are now at a crossroads. Combinatorially profound increases in data about individuals has led to an alternative to population-based RCTs. Genotyping and comprehensive "deep" phenotyping can sort individuals into smaller groups, enabling precise medical decisions at a personal level. In neurology, precision medicine that includes prediction, prevention and personalization requires that genomic and phenomic information further incorporate imaging and behavioral data. In this article, we review the genomic, phenomic, and computational aspects of precision medicine for neurology. After defining biological markers, we discuss some applications of these "-omic" and neuroimaging measures, and then outline the role of computation and ultimately brain simulation. We conclude the article with a discussion of the relation between precision medicine and value-based care.

Relapsing tumefactive demyelination lesions: A unique, distinct inflammatory brain pathology

We report the case of a patient suffering from biopsy-proven relapsing tumefactive demyelinating lesions (TDLs) of the central nervous system who had five relapses in 16 years. No signs/symptoms suggestive of alternative pathologies emerged during the follow-up. A limited benefit was observed with intravenous (IV) high-dose steroids, while both plasma exchange and IV immunoglobulin G (IgG) administration were ineffective. A long-lasting (9 years) but transient clinical stabilization was obtained with cyclophosphamide. Our case supports the view that recurrent TDL is a relapsing brain inflammation not belonging to multiple sclerosis (MS) or myelin oligodendrocyte glycoprotein (MOG)-/AQP4-associated disorders. TDL concept and clinical features should be revised.

Pediatric acquired demyelinating syndromes: updates in diagnosis, testing, and management

PURPOSE OF REVIEW

To highlight the clinical presentation, diagnostic approach, and management of acquired inflammatory demyelinating syndromes in children.

RECENT FINDINGS

The identification of myelin oligodendrocyte glycoprotein antibody-associated disease in 2017 and evolving evidence regarding best practices for management has had a significant impact on pediatric neuroimmunology, as has the shift in treatment of pediatric-onset multiple sclerosis, with the use of high-efficacy disease-modifying therapies early in the disease course.

SUMMARY

With expanding awareness and growing interest in pediatric onset neuroinflammatory conditions, the number of children diagnosed with acquired demyelinating syndromes is rising. It is critical to refine our understanding of the underlying pathophysiological mechanisms in these disorders to provide the most effective care. Much of our practice continues to be modeled on adult care, and further large-scale pediatric studies are necessary to explore the natural history and assess the safety and efficacy of immunotherapies in childhood-onset demyelinating diseases.

Cognitive Impairment, Associated Clinical Factors, and MR Volumetric Measures in Myelin Oligodendrocyte Glycoprotein-IgG-Associated Disease

BACKGROUND AND OBJECTIVES

Cognitive impairment is a common and challenging symptom in multiple sclerosis and neuromyelitis optica spectrum disease; however, data in myelin oligodendrocyte glycoprotein-IgG-associated disease (MOGAD) remain scarce. In this cross-sectional study, we investigated the frequency of cognitive impairment, associated clinical factors, and MRI volumetric measures in MOGAD.

METHODS

Participants were investigated in a single center by certified psychologists and underwent a standardized 3-T-MRI protocol. MRI data were processed with FreeSurfer for gray and white matter volume estimation, presented as a fraction of total intracranial volume. Sera screening for antineural antibodies has been conducted using cell-based assays. The following clinical factors were included in the multivariate logistic regression analysis: sex, age, overall number of previous relapses, and specifically the history of acute disseminated encephalomyelitis (ADEM)/ADEM-like episodes and other brain relapses.

RESULTS

Thirty-two patients with MOGAD (19 female, median age 29.4 years) after a median of 2 relapses with a median EDSS of 1.0 were recruited. Seven patients (21.9%) demonstrated cognitive impairment with the most prevalent deficits in mental flexibility (16.7%), attention (11.1%-14.8%), and verbal working memory (10.3%). 72.4% suffered from fatigue and 42.9% from signs of depression, moderate to severe in 28.6%. The overall number of previous relapses (odds ratio [OR] 1.789, 95% CI 1.041-3.074) and specifically ADEM/ADEM-like episodes (OR 16.929, 95% CI 1.228-233.427) were the only clinical factors associated with cognitive impairment in a multivariate logistic regression model. Screening for antineuronal antibodies remained negative. Cerebral white matter (WM) (0.300 vs 0.317, p = 0.003) and deep gray matter (DGM) (0.036 vs 0.038, p = 0.002) volumes were reduced in patients with MOGAD compared with healthy controls (n = 32). Both cognitive impairment (0.031 vs 0.036, p = 0.003) and history of ADEM/ADEM-like episodes (0.032 vs 0.036, p = 0.006) were associated with reduced DGM volume compared with unaffected patients with MOGAD.

DISCUSSION

Despite a low overall disability, every 5th patient with MOGAD experiences cognitive impairment. Cognitive impairment is associated with a higher number of relapses and particularly ADEM/ADEM-like attacks. Although both WM and DGM atrophies are apparent in MOGAD, the latter only seems to have an association with cognitive impairment.

Myelin oligodendrocyte glycoprotein antibody-associated disease with histopathologic features of primary CNS angiitis without demyelination: Case report and literature review

Primary angiitis of the central nervous system (PACNS) is a rare inflammatory disease that affects both small- and medium-sized vessels of the CNS, while myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is a novel antibody-mediated inflammatory demyelinating disorder that causes damage to the myelin in CNS. We report a case diagnosed as MOGAD due to a history of recurrent myelitis, brain lesions, and positive anti-MOG, but the brain biopsy showed vasculitis without demyelination.

CNS B cell infiltration in tumefactive anti-myelin oligodendrocyte glycoprotein antibody-associated disease

Background

Few studies have examined B cells among patients with anti-myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD), including brain pathology.

Objective

To describe cases of tumefactive MOGAD with B-cell dominant central nervous system (CNS) infiltration.

Methods

In this study, we reviewed three cases with clinical and brain histopathological features with tumefactive MOGAD.

Results

Forty-nine cases of tumefactive brain lesions (TBL) between January 2003 and December 2023 were included; of these, seven had MOGAD. Three underwent a brain biopsy. B-cell dominant CNS infiltration was observed in two cases. In two cases with B-cell dominant CNS infiltration, symptoms included fever, headache, nausea, somnolence, and focal neurological deficits. Cerebrospinal fluid examination revealed both mild pleocytosis and negative oligoclonal IgG bands. Magnetic resonance imaging of the brain revealed large abnormal lesions extending from the basal ganglia to the parietotemporal lobe in both cases. These cases showed a good response to steroids; however, one case relapsed. Brain pathology showed demyelination and perivascular lymphocytic infiltration. One showed small vessel vasculitis. Deposition of the activated complement component was absent or rarely observed. Loss of MOG was observed in two cases.

Conclusion

MOGAD could exhibit B-cell dominant CNS infiltration and small vessel vasculitis. MOGAD should be considered in differential diagnosis of TBL.

Atypical Demyelinating Disorders: MR Imaging Features, Atypical Triggers, and Etiopathogenesis

Atypical demyelinating lesions (ADLs) can be idiopathic, occurring as isolated and self-limited events, or can appear in different stages of relapsing demyelinating diseases. Not infrequently, ADLs occur in inflammatory syndromes associated with exogenous or endogenous toxic factors, metabolic imbalance, or infectious agents. It is important to recognize imaging patterns that indicate an inflammatory/demyelinating substrate in central nervous system lesions and to investigate potential triggers or complicating factors that might be associated. The prognostic and treatment strategies of ADLs are influenced by the underlying etiopathogenesis.

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.

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.

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.

Clinical characteristics of patients with myelin oligodendrocyte glycoprotein antibodies

PURPOSE OF REVIEW

The clinical landscape associated to myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) has undergone a remarkable transformation over the past two decades, primarily driven by advancements in antibody detection techniques that have enhanced both the specificity and sensitivity of assays, enabling the identification of novel clinical phenotypes.

RECENT FINDINGS

Recent pivotal research publications, comprehensive reviews from established research groups, and most notably the first proposed international criteria for MOG-Ab associated disease (MOGAD) have substantially enriched our understanding of the clinical features associated with MOG-Ab. This review presents a comprehensive overview of the clinical characteristics of patients with MOG-Ab, systematically examining each core clinical syndrome defined by the proposed international MOGAD criteria. We incorporated recent insights and discussed potential challenges in applying these criteria across diverse clinical scenarios.

SUMMARY

The proposed international MOGAD criteria provide a comprehensive, homogeneous, and specific framework for characterizing the clinical features of patients with MOG-Ab, encompassing both paediatric and adult populations. In the future, the widespread adoption of specific and reliable assays for MOG-Ab detection, complemented by the development of surrogate fluid and imaging markers, holds promise for better characterizing atypical presentations, only-cerebrospinal fluid positivity and the MOGAD "seronegative" situations.

Radiologic Lag and Brain MRI Lesion Dynamics During Attacks in MOG Antibody-Associated Disease

BACKGROUND AND OBJECTIVES

Knowledge of the evolution of CNS demyelinating lesions within attacks could assist diagnosis. We evaluated intra-attack lesion dynamics in patients with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) vs multiple sclerosis (MS) and aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorder (AQP4+NMOSD).

METHODS

This retrospective observational multicenter study included consecutive patients from Mayo Clinic (USA) and Great Ormond Street Hospital for Children (UK). Inclusion criteria were as follows: (1) MOGAD, MS, or AQP4+NMOSD diagnosis; (2) availability of ≥2 brain MRIs (within 30 days of attack onset); and (3) brain involvement (i.e., ≥1 T2 lesion) on ≥1 brain MRI. The initial and subsequent brain MRIs within a single attack were evaluated for the following: new T2 lesions(s); resolved T2 lesion(s); both; or no change. This was compared between MOGAD, MS, and AQP4+NMOSD attacks. We used the Mann-Whitney U test and χ2/Fisher exact test for statistical analysis.

RESULTS

Our cohort included 55 patients with MOGAD (median age, 14 years; interquartile range [IQR] 5-34; female sex, 29 [53%]) for a total of 58 attacks. The comparison groups included 38 patients with MS, and 19 with AQP4+NMOSD. In MOGAD, the initial brain MRI (median of 5 days from onset [IQR 3-9]) was normal in 6/58 (10%) attacks despite cerebral symptoms (i.e., radiologic lag). The commonest reason for repeat MRI was clinical worsening or no improvement (33/56 [59%] attacks with details available). When compared with the first MRI, the second intra-attack MRI (median of 8 days from initial scan [IQR 5-13]) showed the following: new T2 lesion(s) 27/58 (47%); stability 24/58 (41%); resolution of T2 lesion(s) 4/58 (7%); or both new and resolved T2 lesions 3/58 (5%). Findings were similar between children and adults. Steroid treatment was associated with resolution of ≥1 T2 lesion (6/28 [21%] vs 1/30 [3%], p = 0.048) and reduced the likelihood of new T2 lesions (9/28 vs 18/30, p = 0.03). Intra-attack MRI changes favored MOGAD (34/58 [59%]) over MS (10/38 [26%], p = 0.002) and AQP4+NMOSD (4/19 [21%], p = 0.007). Resolution of ≥1 T2 lesions was exclusive to MOGAD (7/58 [12%]).

DISCUSSION

Radiologic lag is common within MOGAD attacks. Dynamic imaging with frequent appearance and occasional disappearance of lesions within a single attack suggest MOGAD diagnosis over MS and AQP4+NMOSD. These findings have implications for clinical practice, clinical trial attack adjudication, and understanding of MOGAD pathogenesis.

Tumefactive Demyelinating Lesions: An Illustrative Pediatric Case With an Atypical Presentation and Literature Review

Tumefactive demyelinating lesions remain a rare entity and a source of diagnostic difficulty. Here, we report the case of a teenage girl who presented with a one-month history of progressive quadriparesis and symptoms of intracranial hypertension. Brain MRI showed multiple large subcortical white matter lesions with both open- and closed-rim enhancement on gadolinium injection. The patient subsequently underwent a brain biopsy which showed an inflammatory infiltrate and no signs of malignancy. She was treated with pulse intravenous methylprednisolone at a dose of 500mg per day for five days and had rapid improvement. Her symptoms fully resolved after three months. This case highlights the need for better recognition and diagnosis of tumefactive demyelination, potentially avoiding unnecessary invasive diagnostic procedures such as brain biopsies.

Catastrophic tumefactive acute disseminated encephalomyelitis in patient with dengue virus: a case report

Tumefactive demyelinating lesions (TDL) are a rare occurrence among inflammatory demyelinating diseases of the central nervous system, distinguished by tumor-like lesions exceeding 2 cm in diameter. While various etiologies have been associated with TDL, only a limited number of case reports document the coexistence of acute disseminated encephalomyelitis (ADEM) and TDL. Here, we present the case of a female diagnosed with dengue fever two weeks prior, who subsequently developed left hemiparesis and encephalopathy. Both her brain magnetic resonance imaging (MRI) and clinical course align with the characteristics of tumefactive ADEM.

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.

Clinical and radiological characteristics and outcomes of patients with recurrent or relapsing tumefactive demyelination

BACKGROUND

Relapsing or recurrent tumefactive demyelination is rare and has not been studied beyond individual case reports.

OBJECTIVE

We examined the clinical course, neuroimaging, cerebrospinal fluid (CSF), treatment and outcomes of patients with recurrent tumefactive demyelinating lesions (TDLs).

METHODS

We used PubMed to identify reports of recurrent TDLs and included the details of an additional, unpublished patient.

RESULTS

We identified 18 cases (11F, 7 M). The median age at onset of the index TDL was 37 years (range 12-72) and most were solitary lesions 72 % (13/18). CSF-restricted oligoclonal bands (OCBs) were detected in 25 % (4/16). Only one of those tested (n = 13) was positive for AQP4-IgG. A moderate-to-marked treatment response (high dose corticosteroid with or without additional plasmapheresis, IVIg or disease modifying therapies) was evident in 89 % of treated patients. Median EDSS at the median follow-up of 36 months (range 6-144) was 2 (range 1-10). Most remained ambulatory (EDSS < 4 in 13/18), but 1 patient died.

CONCLUSION

The median age of patients with relapsing TDLs is similar to that of typical MS, but differences include a lower female:male sex ratio, larger lesions, and a comparative lack of CSF-restricted OCBs. Outcomes vary among this group of patients ranging from minimal disability through to death.

The landscape of PBMCs in AQP4-IgG seropositive NMOSD and MOGAD, assessed by high dimensional mass cytometry

OBJECTIVES

Data on peripheral blood mononuclear cells (PBMCs) characteristics of aquaporin-4 (AQP4)-IgG seropositive neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are lacking. In this study, we describe the whole PBMCs landscape of the above diseases using cytometry by time-of-flight mass spectrometry (CyTOF).

METHODS

The immune cell populations were phenotyped and clustered using CyTOF isolated from 27 AQP4-IgG seropositive NMOSD, 11 MOGAD patients, and 15 healthy individuals. RNA sequencing was employed to identify critical genes. Fluorescence cytometry and qPCR analysis were applied to further validate the algorithm-based results that were obtained.

RESULTS

We identified an increased population of CD11b+ mononuclear phagocytes (MNPs) in patients with high expression of CCR2, whose abundance may correlate with brain inflammatory infiltration. Using fluorescence cytometry, we confirmed the CCR2+ monocyte subsets in a second cohort of patients. Moreover, there was a wavering of B, CD4+ T, and NKT cells between AQP4-IgG seropositive NMOSD and MOGAD.

CONCLUSIONS

Our findings describe the whole landscape of PBMCs in two similar demyelinated diseases and suggest that, besides MNPs, T, NK and B, cells were all involved in the pathogenesis. The identified cell population may be used as a predictor for monitoring disease development or treatment responses.

Tumefactive demyelinating lesions: a retrospective cohort study in Thailand

Tumefactive demyelinating lesions (TDL), characterized by large (≥ 2 cm) demyelinating lesions mimicking tumors, are a rare manifestation of the central nervous system inflammatory demyelinating diseases (CNS-IDD). Distinguishing TDL from other brain lesions can be challenging, often necessitating biopsy or advanced diagnostics. The natural history of TDL varies among races. This study aimed to assess demographics, clinical and radiological features, laboratory findings, management, and outcomes of Thai patients with TDL. We retrospectively reviewed records of twenty-six patients with TDL from the Multiple Sclerosis and Related Disorders registry from two tertiary medical centers. Among 1102 CNS-IDD patients, 26 (2.4%) had TDL. The median age at TDLs onset was 34.5 years (range 17-75); 69.2% were female. Over 70% manifested TDL as their initial CNS-IDD presentation. Common presenting symptoms included motor deficits, sensory disturbances, and cognitive problems. About two-fifths exhibited multiple lesions, most frequently in the frontoparietal region (46.2%). Half of the patients showed an incomplete ring on post-contrast T1-weighted imaging, with peripheral diffusion-weighted imaging restriction in twenty-one patients. T2-hypointense rims were present in thirteen (56.5%) patients. Brain biopsy was performed in 12 cases (46.1%). Serum aquaporin-4 immunoglobulin was positive in 16.7% of tested (4/24) cases. Serum myelin oligodendrocyte glycoprotein immunoglobulin was negative in all thirteen patients tested. Twenty patients (76.9%) received intravenous corticosteroids for TDL attacks. After the median follow-up period of 48 months (range 6-300), 23.1% experienced CNS-IDD relapses. Median Expanded Disability Status Scale at TDL diagnosis was 4.3 (range 0.0-9.5), and improved to 3.0 (range 0.0-10.0) at the last follow-up. This study suggested that TDL were rare among Thai CNS-IDD patients, frequently presenting as a monophasic condition with a favorable outcome.

Understanding the Pathophysiology and Magnetic Resonance Imaging of Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorders

Magnetic resonance imaging (MRI) has been extensively applied in the study of multiple sclerosis (MS), substantially contributing to diagnosis, differential diagnosis, and disease monitoring. MRI studies have significantly contributed to the understanding of MS through the characterization of typical radiological features and their clinical or prognostic implications using conventional MRI pulse sequences and further with the application of advanced imaging techniques sensitive to microstructural damage. Interpretation of results has often been validated by MRI-pathology studies. However, the application of MRI techniques in the study of neuromyelitis optica spectrum disorders (NMOSD) remains an emerging field, and MRI studies have focused on radiological correlates of NMOSD and its pathophysiology to aid in diagnosis, improve monitoring, and identify relevant prognostic factors. In this review, we discuss the main contributions of MRI to the understanding of MS and NMOSD, focusing on the most novel discoveries to clarify differences in the pathophysiology of focal inflammation initiation and perpetuation, involvement of normal-appearing tissue, potential entry routes of pathogenic elements into the CNS, and existence of primary or secondary mechanisms of neurodegeneration.

Differential Diagnosis of Tumor-like Brain Lesions

Purpose of Review

Tumor-like brain lesions are rare and commonly suggest a neoplastic etiology. Failure to rapidly identify non-neoplastic causes can lead to increased morbidity and mortality. In this review, we describe 10 patients who presented with atypical, non-neoplastic tumor-like brain lesions in which brain biopsy was essential for a correct diagnosis and treatment.

Recent Findings

There has been increasing recognition of autoimmune conditions affecting the nervous system, and many of those diseases can cause tumor-like brain lesions. Currently available reports of non-neoplastic tumor-like brain lesions are scarce. Most case series focus on tumefactive demyelinating lesions, and a comprehensive review including other neuroimmunological conditions such as CNS vasculitis, neurosarcoidosis, histiocytic and infectious etiologies is lacking.

Summary

We review the literature on tumor-like brain lesions intending to increase the awareness and differential diagnosis of non-neoplastic brain tumor mimics. We advocate for earlier brain biopsies, which, in our case series, significantly changed diagnosis, management, and outcomes.

Non-demyelinating disorders mimicking and misdiagnosed as NMOSD: a literature review

BACKGROUND

Differentiating neuromyelitis optica spectrum disorder (NMOSD) from its mimics is crucial to avoid misdiagnosis, especially in the absence of aquaporin-4-IgG. While multiple sclerosis (MS) and myelin oligodendrocyte glycoprotein-IgG associated disease (MOGAD) represent major and well-defined differential diagnoses, non-demyelinating NMOSD mimics remain poorly characterized.

METHODS

We conducted a systematic review on PubMed/MEDLINE to identify reports of patients with non-demyelinating disorders that mimicked or were misdiagnosed as NMOSD. Three novel cases seen at the authors' institutions were also included. The characteristics of NMOSD mimics were analyzed and red flags associated with misdiagnosis identified.

RESULTS

A total of 68 patients were included; 35 (52%) were female. Median age at symptoms onset was 44 (range, 1-78) years. Fifty-six (82%) patients did not fulfil the 2015 NMOSD diagnostic criteria. The clinical syndromes misinterpreted for NMOSD were myelopathy (41%), myelopathy + optic neuropathy (41%), optic neuropathy (6%), or other (12%). Alternative etiologies included genetic/metabolic disorders, neoplasms, infections, vascular disorders, spondylosis, and other immune-mediated disorders. Common red flags associated with misdiagnosis were lack of cerebrospinal fluid (CSF) pleocytosis (57%), lack of response to immunotherapy (55%), progressive disease course (54%), and lack of magnetic resonance imaging gadolinium enhancement (31%). Aquaporin-4-IgG positivity was detected in five patients by enzyme-linked immunosorbent assay (n = 2), cell-based assay (n = 2: serum, 1; CSF, 1), and non-specified assay (n = 1).

CONCLUSIONS

The spectrum of NMOSD mimics is broad. Misdiagnosis frequently results from incorrect application of diagnostic criteria, in patients with multiple identifiable red flags. False aquaporin-4-IgG positivity, generally from nonspecific testing assays, may rarely contribute to misdiagnosis.

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.

Tumefactive brain parenchymal neurosarcoidosis

BACKGROUND

Enhancing brain parenchymal disease, and especially tumefactive lesions, are an uncommon manifestation of neurosarcoidosis. Little is known about the clinical features of tumefactive lesions and their impact on management and outcomes, which this study aims to characterize.

METHODS

Patients with pathologically-confirmed sarcoidosis were retrospectively reviewed and included if brain lesions were: (1) intraparenchymal, (2) larger than 1 cm in diameter, and (3) associated with edema and/or mass effect.

RESULTS

Nine patients (9/214, 4.2%) were included. Median onset age was 37 years. Diagnosis was confirmed by brain parenchymal biopsies in 5 (55.6%). Median modified Rankin scale (mRS) score was 2 (range 1-4) at initial presentation. Common manifestations included headache (77.8%), cognitive dysfunction (66.7%), and seizures (44.4%). Sixteen lesions were present in 9 patients. The frontal lobe (31.3%) was most affected, followed by the subinsular region (12.5%), basal ganglia (12.5%%), cerebellum (12.5%), and pons (12.5%). MRI characteristics of the dominant lesions included spherical morphology (77.8%), perilesional edema (100.0%), mass effect (55.6%), well-demarcated borders (66.7%), and contrast enhancement (100.0%; 55.6% heterogeneous). Leptomeningitis was frequently present (77.8%). All required corticosteroid-sparing treatments, and most (55.6%) needed at least a third line of treatment (infliximab used in 44.4%). All patients relapsed (median 3 relapses, range 1-9). Median last mRS was 1.0 after median follow-up of 86 months, with significant residual deficits in 55.6%.

CONCLUSION

Tumefactive brain parenchymal lesions are uncommon, usually affect the supratentorial brain along with leptomeningitis, and are refractory to initial treatments with a high risk of relapse. Significant sequelae were encountered despite a favorable median last mRS.

Differential diagnosis of suspected multiple sclerosis: an updated consensus approach

Accurate diagnosis of multiple sclerosis requires careful attention to its differential diagnosis-many disorders can mimic the clinical manifestations and paraclinical findings of this disease. A collaborative effort, organised by The International Advisory Committee on Clinical Trials in Multiple Sclerosis in 2008, provided diagnostic approaches to multiple sclerosis and identified clinical and paraclinical findings (so-called red flags) suggestive of alternative diagnoses. Since then, knowledge of disorders in the differential diagnosis of multiple sclerosis has expanded substantially. For example, CNS inflammatory disorders that present with syndromes overlapping with multiple sclerosis can increasingly be distinguished from multiple sclerosis with the aid of specific clinical, MRI, and laboratory findings; studies of people misdiagnosed with multiple sclerosis have also provided insights into clinical presentations for which extra caution is warranted. Considering these data, an update to the recommended diagnostic approaches to common clinical presentations and key clinical and paraclinical red flags is warranted to inform the contemporary clinical evaluation of patients with suspected multiple sclerosis.