Diagnosis of neuromyelitis optica (NMO) spectrum disorders: is MRI obsolete?

Differentiation between multiple sclerosis and neuromyelitis optic spectrum disorders with multilevel fMRI features: A machine learning analysis

The conventional statistical approach for analyzing resting state functional MRI (rs-fMRI) data struggles to accurately distinguish between patients with multiple sclerosis (MS) and those with neuromyelitis optic spectrum disorders (NMOSD), highlighting the need for improved diagnostic efficacy. In this study, multilevel functional metrics including resting state functional connectivity, amplitude of low frequency fluctuation (ALFF), and regional homogeneity (ReHo) were calculated and extracted from 116 regions of interest in the anatomical automatic labeling atlas. Subsequently, classifiers were developed using different combinations of these selected features to distinguish between MS and NMOSD. Compared to models based on individual MRI features, support vector machine (SVM) and logistic regression (LR) models that integrated multilevel functional features such as RSFC, ALFF, and ReHo demonstrated the highest levels of performance on the testing cohorts (SVM, AUC = 0.857; LR, AUC = 0.929). Adding structural features of gray matter volume (GMV) data did not notably improve the classification performance of the machine learning models using multilevel rs-fMRI features. Notably, similar trends were observed across different brain templates, with models based on RSFC, ALFF, and ReHo yielding optimal performance. These findings suggest that utilizing multilevel fMRI features can effectively differentiate between MS and NMOSD patients.

MRI Patterns Distinguish AQP4 Antibody Positive Neuromyelitis Optica Spectrum Disorder From Multiple Sclerosis

Neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) are inflammatory diseases of the CNS. Overlap in the clinical and MRI features of NMOSD and MS means that distinguishing these conditions can be difficult. With the aim of evaluating the diagnostic utility of MRI features in distinguishing NMOSD from MS, we have conducted a cross-sectional analysis of imaging data and developed predictive models to distinguish the two conditions. NMOSD and MS MRI lesions were identified and defined through a literature search. Aquaporin-4 (AQP4) antibody positive NMOSD cases and age- and sex-matched MS cases were collected. MRI of orbits, brain and spine were reported by at least two blinded reviewers. MRI brain or spine was available for 166/168 (99%) of cases. Longitudinally extensive (OR = 203), "bright spotty" (OR = 93.8), whole (axial; OR = 57.8) or gadolinium (Gd) enhancing (OR = 28.6) spinal cord lesions, bilateral (OR = 31.3) or Gd-enhancing (OR = 15.4) optic nerve lesions, and nucleus tractus solitarius (OR = 19.2), periaqueductal (OR = 16.8) or hypothalamic (OR = 7.2) brain lesions were associated with NMOSD. Ovoid (OR = 0.029), Dawson's fingers (OR = 0.031), pyramidal corpus callosum (OR = 0.058), periventricular (OR = 0.136), temporal lobe (OR = 0.137) and T1 black holes (OR = 0.154) brain lesions were associated with MS. A score-based algorithm and a decision tree determined by machine learning accurately predicted more than 85% of both diagnoses using first available imaging alone. We have confirmed NMOSD and MS specific MRI features and combined these in predictive models that can accurately identify more than 85% of cases as either AQP4 seropositive NMOSD or MS.

Magnetic resonance imaging in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease of the central nervous system (CNS) associated with antibodies to aquaporin-4 (AQP4), which has distinct clinical, radiological and pathological features, but also has some overlap with multiple sclerosis and myelin oligodendrocyte glycoprotein (MOG) antibody associated disease. Early recognition of NMOSD is important because of differing responses to both acute and preventive therapy. Magnetic resonance (MR) imaging has proved essential in this process. Key MR imaging clues to the diagnosis of NMOSD are longitudinally extensive lesions of the optic nerve (more than half the length) and spinal cord (three or more vertebral segments), bilateral optic nerve lesions and lesions of the optic chiasm, area postrema, floor of the IV ventricle, periaqueductal grey matter, hypothalamus and walls of the III ventricle. Other NMOSD-specific lesions are denoted by their unique morphology: heterogeneous lesions of the corpus callosum, 'cloud-like' gadolinium (Gd)-enhancing white matter lesions and 'bright spotty' lesions of the spinal cord. Other lesions described in NMOSD, including linear periventricular peri-ependymal lesions and patch subcortical white matter lesions, may be less specific. The use of advanced MR imaging techniques is yielding further useful information regarding focal degeneration of the thalamus and optic radiation in NMOSD and suggests that paramagnetic rim patterns and changes in normal appearing white matter are specific to MS. MR imaging is crucial in the early recognition of NMOSD and in directing testing for AQP4 antibodies and guiding immediate acute treatment decisions. Increasingly, MR imaging is playing a role in diagnosing seronegative cases of NMOSD.

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.

The latest diagnostic criteria and treatment options for neuromyelitis optica

Neuromyelitis optica, also known as Devic disease, is an autoimmune disorder that affects the spinal cord and optic nerve. This atypical demyelinating syndrome can be difficult to diagnose and responds poorly to treatments that are used for multiple sclerosis, a similar demyelinating disease. This article discusses the epidemiology, pathophysiology, clinical presentation, latest diagnostic criteria, and treatment options for neuromyelitis optica and neuromyelitis spectrum disorders.

Tumefactive Demyelination Associated with Bilateral Optic Neuritis in Neuromyelitis Optica Spectrum Disorders

Tumefactive demyelination is an uncommon neurological disorder mimicking tumors. It is one of the rare varieties of demyelinating disorders, often causing diagnostic dilemma among neuroscientists. The literature tells us about approaching these patients added by peculiar neuroimaging findings. Neuromyelitis optica is an immune mediated inflammatory clinical disorder, typically involving optic nerves bilaterally and longitudinally extensive transverse myelitis. With the revelation of aquaporin four channels, its distribution in the brain and related antibody, the concept of neuromyelitis optica spectra disorders has been evolved. In this case report, our intention is to present a young female who presented with bilateral vision loss with tumor-like mass lesion in cerebral cortex. Such an association of bilateral optic neuropathy involving chiasmatic region, suggestive of neuromyelitis optica spectrum disorder (NMOSD) with tumefactive demyelination is rarely reported in the literature.

Neuromyelitis optica spectrum disorders in Arabian Gulf (NMOAG); establishment and initial characterization of a patient registry

OBJECTIVE

To describe the clinical and radiological characteristics of neuromyelitis optica spectrum disorders (NMOSD) patients from the Arabian Gulf relative to anti-aquaporin 4 antibody serostatus.

METHODS

Retrospective multicentre study of hospital records of patients diagnosed with NMOSD based on 2015 International Panel on NMOSD Diagnosis (IPND) consensus criteria.

RESULTS

One hundred forty four patients were evaluated, 64.3% were anti-AQP4 antibody positive. Mean age at onset and disease duration were 31±12 and 7 ± 6 years respectively. Patients were predominantly female (4.7:1). Overall; relapsing course (80%) was more common than monophasic (20%). Optic neuritis was the most frequent presentation (48.6%), regardless of serostatus. The proportion of patients (54.3%) with visual acuity of ≤ 0.1 was higher in the seropositive group (p = 0.018). Primary presenting symptoms of transverse myelitis (TM) were observed in 29% of patients, and were the most significant correlate of hospitalization (p<0.001). Relative to anti-APQ4 serostatus, there were no significant differences in terms of age of onset, course, relapse rates or efficacy outcomes except for oligoclonal bands (OCB), which were more often present in seronegative patients (40% vs.22.5%; p = 0.054). Irrespective of serostatus, several disease modifying therapies were instituted including steroids or immunosuppressives, mostly, rituximab and azathioprine in the cohort irrespective of serostatus. The use of rituximab resulted in reduction in disease activity.

CONCLUSION

This is the first descriptive NMOSD cohort in the Arabian Gulf region. Seropositive patients were more prevalent with female predominance. Relapsing course was more common than monophasic. However, anti-AQP4 serostatus did not impact disease duration, relapse rate or therapeutic effectiveness. These findings offer new insights into natural history of NMOSD in patients of the Arabian Gulf and allow comparison with patient populations in different World regions.

Aquaporin 4 distribution in the brain and its relevance for the radiological appearance of neuromyelitis optica spectrum disease

BACKGROUND AND PURPOSE

To determine the precise incidence of lesions at sites of high Aquaporin-4 expression (hAQP4) and their possible association with known neuromyelitis optica spectrum disease (NMOSD) lesions patterns.

MATERIALS AND METHODS

A retrospective analysis of brain and, when available, spinal cord MRI scans of 54 NMOSD patients recruited among the French NMOSD cohort was performed. Brain lesions were annotated as MS-like, non-specific, or evocative of NMOSD. The topography of hAQP4 was reassessed by human brain atlas. The incidence of lesions in hAQP4 and their association with lesions evocative of NMOSD was estimated.

RESULTS

Among those included (41/54 female, mean age: 45 years) 47/54 (87%) presented brain lesions. Twenty-six/47 (55%) had lesions in hAQP4. Thirty-two/54 patients (60%) had lesions considered evocative of NMOSD. The majority of them also presented lesions in hAQP4 (65%, 21/32). Patients with lesions in hAQP4 and lesions evocative of NMOSD demonstrated more extensive myelitis compared to the other patients (7 [6-10] versus 4 [3-5] vertebral segments, P=0.009).

CONCLUSION

The coexistence of lesions evocative of NMOSD and in hAQP4 is associated with significantly more extensive myelitis, and might have pathophysiological and clinical significance.

Predictive value of conventional MRI parameters in first spinal attacks of neuromyelitis optica spectrum disorder

Background:

While spinal cord (SC) attacks of neuromyelitis optica spectrum disorder (NMOSD) are often devastating, signs predictive of their poor clinical outcome have been elusive until now, except for the delay in initiating plasma exchange (PE).

Objective:

We studied the correlation between conventional non-standardized magnetic resonance imaging (MRI) parameters, PE treatment, and clinical data obtained at nadir and recovery.

Methods:

Retrospective study of first SC attacks of NMOSD.

Results:

Sixty-nine Afro-Caribbean NMOSD patients were included (aquaporin-4 (AQP4) antibodies positive in 65%). Median nadir and residual expanded disability status score (EDSS) were, respectively, 7.5 and 4.0. In bivariate analysis, all conventional MRI parameters were correlated with nadir and residual EDSS. In multivariate analysis, nadir EDSS correlated with lesion length ( p = 0.022) and edema ( p = 0.019), whereas residual EDSS correlated with T1w (T1-weighted) hypointense signal ( p = 0.003). Gadolinium enhancement was not associated with outcome.

Conclusion:

A specific pattern of lesions in conventional MRI data is differentially associated with nadir and residual EDSS. Lesions associated with poor prognosis should prompt highly efficient treatment.

Comprehensive review of neuromyelitis optica and clinical characteristics of neuromyelitis optica patients in Puerto Rico

Neuromyelitis optica (NMO) is an immune-mediated inflammatory disorder of the central nervous system. It is characterized by concurrent inflammation and demyelination of the optic nerve (optic neuritis [ON]) and the spinal cord (myelitis). Multiple studies show variations in prevalence, clinical, and demographic features of NMO among different populations. In addition, ethnicity and race are known as important factors on disease phenotype and clinical outcomes. There are little data on information about NMO patients in underserved groups, including Puerto Rico (PR). In this research, we will provide a comprehensive overview of all aspects of NMO, including epidemiology, environmental risk factors, genetic factors, molecular mechanism, symptoms, comorbidities and clinical differentiation, diagnosis, treatment, its management, and prognosis. We will also evaluate the demographic features and clinical phenotype of NMO patients in PR. This will provide a better understanding of NMO and establish a basis of knowledge that can be used to improve care. Furthermore, this type of population-based study can distinguish the clinical features variation among NMO patients and will provide insight into the potential mechanisms that cause these variations.

Clinical and radiological characteristics of neuromyelitis optica spectrum disorder in the North Egyptian Nile Delta

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune demyelinating disorder of the central nervous system that was previously thought to be a subtype of multiple sclerosis (MS). Epidemiology studies of NMOSD are rare in both Middle East and North African countries. To our knowledge, there are no such studies in Egypt. Herein, we describe a case series of NMOSD patients from North Egyptian Nile Delta region and compare them to NMOSD in other parts in the Middle East and the world.

METHODS

This is a case series study of NMOSD patients who were seen at the neuroimmunology clinic, Elhadara Hospital, University of Alexandria, Egypt, from January 2017 to January 2018. We describe their clinical, serological and radiological features.

RESULTS

Our study identified twenty Egyptian patients, all of who fulfilled the 2015 international NMOSD diagnostic criteria. Ten tested positive for AQP4 antibodies in the serum while the other ten were seronegative. The mean age at onset was 27.8 years with an average disease duration of 6.8 years. There was a strong female predominance with a ratio of 5.6:1. We identified clinical features of the cohort that differ from those reported in other worldwide studies.

INTERPRETATION

This is the first NMOSD case series in Egypt. Despite some limitation in testing and access to care, there are features of our NMOSD cases that appear to be different from other worldwide cohorts reported in the literature.

Neuromyelitis optica spectrum disorders with and without connective tissue disorders

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) often coexist with connective tissue disorders (CTD). The aim of this study was to investigate and compare the features of NMOSD with and without CTD.

METHODS

NMOSD patients with (n = 18) and without CTD (n = 39) were enrolled, and the clinical, laboratory, and magnetic resonance imaging (MRI) features of the two groups were assessed.

RESULTS

Most of the demographic and clinical features examined were similar between NMOSD patients with and without CTD. Serum immunoglobulin G (IgG), percentage of γ-globulin and seropositivity for several other autoantibodies were significantly elevated in NMOSD patients with CTD (P < 0.05). NMOSD with CTD was marked by longer spinal cord lesions and a lower frequency of short transverse myelitis (TM) than NMOSD without CTD (P < 0.05). NMOSD with CTD also featured more T1 hypointensity and T2 bright spotty lesions (BSLs) on MRI than NMOSD without CTD (P = 0.001 and 0.011, respectively). There were no other differences in laboratory, MRI and clinical characteristics between different NMOSD subtypes.

CONCLUSIONS

A few characteristics differed between NMOSD with and without CTD. NMOSD patients with CTD had higher serum IgG, longer spinal cord lesions, a lower frequency of short TM and more T1 hypointensity and T2 BSLs on spinal MRI than NMOSD patients without CTD.

Neuromyelitis Optica Spectrum Disorders: Spectrum of MR Imaging Findings and Their Differential Diagnosis

Neuromyelitis optica (NMO) is an autoimmune demyelinating disorder for which the aquaporin-4 (AQP4) water channels are the major target antigens. Advances in the understanding of NMO have clarified several points of its pathogenesis, clinical manifestations, and imaging patterns. A major advance was the discovery of the AQP4 antibody, which is highly specific for this disorder. Descriptions of new clinical and radiologic features in seropositive patients have expanded the spectrum of NMO, and the term NMO spectrum disorder (NMOSD) has been adopted. NMOSD is now included in a widening list of differential diagnoses. Acknowledgment of NMOSD imaging patterns and their mimicry of disorders has been crucial in supporting early NMOSD diagnosis, especially for unusual clinical manifestations of this demyelinating disease. This pictorial review summarizes the wide imaging spectrum of NMOSD and its differential diagnosis, as well as its historical evolution, pathophysiology, and clinical manifestations. ^©RSNA, 2018.

Incidence of neuromyelitis optica spectrum disorder in the Central Denmark Region

OBJECTIVES

Neuromyelitis optica (NMO)/NMO spectrum disorder (NMOSD) may be misdiagnosed as multiple sclerosis. The aim of this study was to (i) to measure AQP4-IgG in patients who fulfilled the clinical and radiological criteria of NMOSD in the Central Denmark Region and (ii) to estimate the incidence of NMOSD in the region, according to both the 2006 Wingerchuk criteria and the 2015 International Panel for NMO Diagnosis criteria.

MATERIALS AND METHODS

Medical records of all patients diagnosed with a demyelinating disorder in the region from 1 January 2012 to 31 December 2013 were reviewed. Patients were classified as having (i) "NMO" if the 2006 criteria were met, (ii) "NMOSD with AQP4-IgG" or (iii) "NMOSD without/unknown AQP-IgG" if the new 2015 NMOSD criteria were met. Patients with core symptoms were invited to provide a blood sample for AQP4-IgG analysis with an enzyme-linked immunosorbent assay and a cell-based indirect immunofluorescence assay.

RESULTS

In 191 patients with core symptoms, one met the 2015 NMOSD with AQP4-IgG criteria. Two patients met the 2006 NMO and 2015 NMOSD without/unknown AQP4-IgG criteria. Among 108 patients providing a blood sample, all were seronegative. The estimated incidence of NMO (2006 criteria) and NMOSD (2015 criteria) was 0.08 and 0.12 per 100 000 person-years, respectively.

CONCLUSION

NMO/NMOSD is a rare disease in the Central Denmark Region, with a considerably lower incidence rate than previously estimated in a neighbouring region.

Frequency of brain MRI abnormalities in neuromyelitis optica spectrum disorder at presentation: A cohort of Latin American patients

BACKGROUND

Brain magnetic resonance imaging (BMRI) lesions were classically not reported in neuromyelitis optica (NMO). However, BMRI lesions are not uncommon in NMO spectrum disorder (NMOSD) patients.

OBJECTIVE

To report BMRI characteristic abnormalities (location and configuration) in NMOSD patients at presentation.

METHODS

Medical records and BMRI characteristics of 79 patients with NMOSD (during the first documented attack) in Argentina, Brazil and Venezuela were reviewed retrospectively.

RESULTS

BMRI abnormalities were observed in 81.02% of NMOSD patients at presentation. Forty-two patients (53.1%) showed typical-NMOSD abnormalities. We found BMRI abnormalities at presentation in the brainstem/cerebellum (n = 26; 32.9%), optic chiasm (n = 16; 20.2%), area postrema (n = 13; 16.4%), thalamus/hypothalamus (n = 11; 13.9%), corpus callosum (n = 11; 13.9%), periependymal-third ventricle (n = 9; 11.3%), corticospinal tract (n = 7; 8.8%), hemispheric white matter (n = 1; 1.2%) and nonspecific areas (n = 49; 62.03%). Asymptomatic BMRI lesions were more common. The frequency of brain MRI abnormalities did not differ between patients who were positive and negative for aquaporin 4 antibodies at presentation.

CONCLUSION

Typical brain MRI abnormalities are frequent in NMOSD at disease onset.

Ring-enhancing spinal cord lesions in neuromyelitis optica spectrum disorders

OBJECTIVE

We assessed the frequency and characteristics of ring-enhancing spinal cord lesions in neuromyelitis optica spectrum disorder (NMOSD) myelitis and myelitis of other cause.

METHODS

We reviewed spinal cord MRIs for ring-enhancing lesions from 284 aquaporin-4 (AQP4)-IgG seropositive patients at Mayo Clinic from 1996 to 2014. Inclusion criteria were as follows: (1) AQP4-IgG seropositivity, (2) myelitis attack and (3) MRI spinal cord demonstrating ring-enhancement. We identified two groups of control patients with: (1) longitudinally extensive myelopathy of other cause (n=66) and (2) myelitis in the context of a concurrent or subsequent diagnosis of multiple sclerosis (MS) from a population-based cohort (n=30).

RESULTS

Ring-enhancement was detected in 50 of 156 (32%) myelitis episodes in 41 patients (83% single; 17% multiple attacks). Ring-enhancement was noted on sagittal and axial images in 36 of 43 (84%) ring enhancing myelitis episodes and extended a median of two vertebral segments (range, 1-12); in 21 of 48 (44%) ring enhancing myelitis episodes, the ring extended greater than or equal to three vertebrae. Ring-enhancement was accompanied by longitudinally extensive (greater than or equal to three vertebral segments) T2-hyperintensity in 44 of 50 (88%) ring enhancing myelitis episodes. One case of a spinal cord biopsy during ring-enhancing myelitis revealed tissue vacuolation and loss of AQP4 immunoreactivity with preserved axons. The clinical characteristics of ring-enhancing myelitis episodes did not differ from non-ring-enhancing episodes. Ring-enhancing spinal cord lesions were more common in NMOSD than other causes of longitudinally extensive myelopathy (50/156 (32%) vs 0/66 (0%); p≤0.001) but did not differ between NMOSD and MS (50/156 (32%) vs 6/30 (20%); p=0.20).

CONCLUSIONS

Spinal cord ring-enhancement accompanies one-third of NMOSD myelitis episodes and distinguishes NMOSD from other causes of longitudinally extensive myelopathies but not from MS.

Comparison of brain and spinal cord magnetic resonance imaging features in neuromyelitis optica spectrum disorders patients with or without aquaporin-4 antibody

BACKGROUND

The spinal cord and brain measurements are rarely investigated in neuromyelitis optica (NMO) patients with and without antibodies to aquaporin-4 (AQP4), directly compared to multiple sclerosis (MS) patients.

OBJECTIVES

To investigate magnetic resonance imaging (MRI) features of both brain and spinal cord in NMO patients with and without antibodies to AQP4, compared with MS patients and healthy controls (HC).

METHODS

We recruited 55 NMO including 30 AQP4 (+) and 25 AQP4 (-), 25 MS and 25 HC. Brain and spinal cord MRIs were obtained for each participant. Brain lesions (BL), whole brain and deep grey matter volumes (DGMV), white matter diffusion metrics and spinal cord lesions were measured and compared among groups.

RESULTS

The incidence of BL was lower in the AQP4 (+) group than in the AQP4 (-) and MS groups (p<0.05). In the AQP4 (+) group, there was a lower incidence of infratentorial lesions (ITL) and higher spinal cord lesions length than in the MS group (p<0.05). The thalamic and hippocampal volumes were smaller in the AQP4 (-) group and MS group than in the HC group (p<0.05).

CONCLUSIONS

The NMO patients with AQP4 (-) showed higher prevalence of BL, ITL, and similar spinal cord lesion length, compared to AQP4 (+), and demonstrated deep grey matter atrophy, suggesting an intermediate phenotype between that of typical MS and NMO.

What do we know about brain contrast enhancement patterns in neuromyelitis optica?

Neuromyelitis optica (NMO) is an autoimmune disorder of the central nervous system that usually presents with acute myelitis and/or optic neuritis. Recently, some brain magnetic resonance imaging findings have been described in NMO that are important in the differential diagnosis. Pencil-thin, leptomeningeal, and cloud-like enhancement may be specific to NMO. These patterns are usually seen during relapses. Recognizing these lesions and enhancement patterns may expedite the diagnosis and allows early effective treatment. The purpose of this article is to review the latest knowledge and to share our experience with the contrast enhancement patterns of NMO brain lesions.

Differentiating neuromyelitis optica from other causes of longitudinally extensive transverse myelitis on spinal magnetic resonance imaging

BACKGROUND

Although spinal magnetic resonance imaging (MRI) findings of neuromyelitis optica (NMO) have been described, there is limited data available that help differentiate NMO from other causes of longitudinally extensive transverse myelitis (LETM).

OBJECTIVE

To investigate the spinal MRI findings of LETM that help differentiate NMO at the acute stage from multiple sclerosis (MS) and other causes of LETM.

METHODS

We enrolled 94 patients with LETM into our study. Bright spotty lesions (BSL), the lesion distribution and location were evaluated on axial T2-weighted images. Brainstem extension, cord expansion, T1 darkness and lesion enhancement were noted. We also reviewed the brain MRI of the patients during LETM.

RESULTS

Patients with NMO had a greater amount of BSL and T1 dark lesions (p < 0.001 and 0.003, respectively). The lesions in NMO patients were more likely to involve greater than one-half of the spinal cord's cross-sectional area; to enhance and be centrally-located, or both centrally- and peripherally-located in the cord. Of the 62 available brain MRIs, 14 of the 27 whom were NMO patients had findings that may be specific to NMO.

CONCLUSIONS

Certain spinal cord MRI features are more commonly seen in NMO patients and so obtaining brain MRI during LETM may support diagnosis.

Moyamoya disease in a patient with neuromyelitis optica

Moyamoya disease can be associated with autoimmune disease such as thyrotoxicosis, but there has been only one report of association with neuromyelitis optica (NMO). We report another case of this combination with the presence of anti-SSA antibody in addition to the NMO-immunoglobulin G. The patient presented limb weakness along with unsteady gait and numbness. A magnetic resonance imaging (MRI) of the spine showed extensive intramedullary hyperintense signals at C2 to T3 levels. On the other hand, no lesions were found on the MRI of the brain. The patient tested positive for anti-aquaporin-4 antibody and anti-SSA antibody which confirms the diagnosis of NMO. A magnetic resonance angiography scan of the brain revealed a bilateral distal occlusion of the internal carotid arteries (ICAs) as well as occlusions of the middle cerebral arteries (MCAs) with fine collaterals in the region which confirms the diagnosis of moyamoya disease. This report suggests that autoimmunity may be an important factor in the pathogenesis of moyamoya disease in some patients.

Predictive value of MRI parameters in severity and recovery of first-episode myelitis in aquaporin-4 antibody disease

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) associated with aquaporin-4 antibodies (AQP4-Ab) typically causes longitudinally-extensive transverse myelitis (LETM). Few data exist about the association of MRI features with LETM attack severity and recovery.

METHODS

AQP4-Ab positive NMOSD patients with a first myelitis attack were retrospectively identified and spinal MRI scans reviewed. Association of MRI features with EDSS scores at attack nadir and recovery was evaluated.

RESULTS

22 patients were included. Median nadir EDSS score was 8 (range 1 to 8.5). Nadir EDSS scores correlated with total MRI lesion length (r=0.48, p=0.025), higher scores were seen in those with gadolinium enhancement (p=0.025) and there was a trend towards higher scores with central cord involvement. The median recovery EDSS was 6 (range 0 to 10). Total lesion length correlated with poor recovery (r=0.48, p=0.027) but this was confounded by correlation between nadir and recovery EDSS scores.

CONCLUSION

We confirm that myelitis in AQP4-Ab disease is severe and show that the severity correlates with lesion length and residual disability. Spinal cord lesions in first myelitis attacks are similar to appearances reported later in the disease course, with propensity to involve the central grey matter and high frequency of cord oedema and T1 hypointensity.

Demographic and clinical features of neuromyelitis optica: A review

The comparative clinical and demographic features of neuromyelitis optica (NMO) are not well known. In this review we analyzed peer-reviewed publications for incidence and prevalence, clinical phenotypes, and demographic features of NMO. Population-based studies from Europe, South East and Southern Asia, the Caribbean, and Cuba suggest that the incidence and prevalence of NMO ranges from 0.05-0.4 and 0.52-4.4 per 100,000, respectively. Mean age at onset (32.6-45.7) and median time to first relapse (8-12 months) was similar. Most studies reported an excess of disease in women and a relapsing course, particularly in anti-aquaporin 4 antibody (anti AQP4-IgG)-positive patients. Ethnicity may have a bearing on disease phenotype and clinical outcome. Despite limitations inherent to the review process, themes noted in clinical and demographic features of NMO among different populations promote a more global understanding of NMO and strategies to address it.

Comparison between the cranial magnetic resonance imaging features of neuromyelitis optica spectrum disorder versus multiple sclerosis in Taiwanese patients

Background

Neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) are inflammatory diseases of the central nervous system with different pathogenesis, brain lesion patterns, and treatment strategies. However, it is still difficult to distinguish these two disease entities by neuroimaging studies. Herein, we attempt to differentiate NMOSD from MS by comparing brain lesion patterns on magnetic resonance imaging (MRI).

Methods

The medical records and cranial MRI studies of patients with NMOSD diagnosed according to the 2006 Wingerchuk criteria and the presence of anti-aquaporin 4 (anti-AQP4) antibodies, and patients with MS diagnosed according to the Poser criteria, were retrospectively reviewed.

Results

Twenty-five NMOSD and 29 MS patients were recruited. The NMOSD patients became wheelchair dependent earlier than MS patients (log rank test; P = 0.036). Linear ependymal (28% vs. 0%, P = 0.003) and punctate lesions (64% vs. 28%, P = 0.013) were more frequently seen in NMOSD patients. Ten NMOSD patients (40%) had brain lesions that did not meet the Matthews criteria (MS were separated from NMOSD by the presence of at least 1 lesion adjacent to the body of the lateral ventricle and in the inferior temporal lobe; or the presence of a subcortical U-fiber lesion or a Dawson finger-type lesion). The different image patterns of NMOSD didn’t correlate with the clinical prognosis. However, NMOSD patients with more (≧10) brain lesions at onset became wheelchair dependence earlier than those with fewer (<10) brain lesions (log rank test; P < 0.001).

Conclusions

The diagnostic sensitivity of NMOSD criteria can be increased to 56% by combining the presence of linear ependymal lesions with unmet the Matthews criteria. The prognoses of NMOSD and MS are different. A specific imaging marker, the linear ependymal lesion, was present in some NMOSD patients. The diagnosis of NMOSD can be improved by following the evolution of this imaging feature when anti-AQP4 antibody test results are not available.

Neuromyelitis optica spectrum disorders without and with autoimmune diseases

Background

Neuromyelitis optica spectrum disorder (NMOSD) can coexist with non-organ-specific or organ-specific autoimmune diseases. The aim of this study was to investigate and compare the features between NMOSD without and with autoimmune diseases, and NMOSD with non-organ-specific and organ-specific autoimmune diseases.

Methods

One hundred and fifty five NMOSD patients without autoimmune diseases (n = 115) and with autoimmune diseases (n = 40) were enrolled. NMOSD with autoimmune diseases were divided by organ-specific autoimmune diseases. The clinical, laboratory and magnetic resonance imaging features between two groups were assessed.

Results

Motor deficit was less frequent in NMOSD patients with non-organ-specific autoimmune diseases (p = 0.024). Cerebrospinal fluid white blood cell and protein, serum C-reactive protein and immunoglobulin G were lower in NMOSD patients without autoimmune diseases, while several autoantibodies seropositivity and thyroid indexes were significantly higher in NMOSD patients with autoimmune diseases (p < 0.05). No difference was found in other clinical and laboratory characteristics between different NMOSD subtypes (p > 0.05). NMOSD patients with autoimmune diseases had higher brain abnormalities than NMOSD without autoimmune diseases (p < 0.001).

Conclusions

The characteristics between NMOSD without and with autoimmune diseases were similar. NMOSD with autoimmune diseases have high frequency of brain abnormalities.

Conventional and advanced imaging in neuromyelitis optica

Myelitis and optic neuritis are prototypic clinical presentations of both multiple sclerosis and neuromyelitis optica. Once considered a subtype of multiple sclerosis, neuromyelitis optica, is now known to have a discrete pathogenesis in which antibodies to the water channel, aquaporin 4, play a critical role. Timely differentiation of neuromyelitis optica from MS is imperative, determining both prognosis and treatment strategy. Early, aggressive immunosuppression is required to prevent the accrual of severe disability in neuromyelitis optica; conversely, MS-specific therapies may exacerbate the disease. The diagnosis of neuromyelitis optica requires the integration of clinical, MR imaging, and laboratory data, but current criteria are insensitive and exclude patients with limited clinical syndromes. Failure to recognize the expanding spectrum of cerebral MR imaging patterns associated with aquaporin 4 antibody seropositivity adds to diagnostic uncertainty in some patients. We present the state of the art in conventional and nonconventional MR imaging in neuromyelitis optica and review the place of neuroimaging in the diagnosis, management, and research of the condition.

Magnetic resonance imaging in neuromyelitis optica

Neuromyelitis optica (NMO), or Devic’s disease, is a rare demyelinating disorder of the central nervous system that has a predilection for the optic nerve and spinal cord. Magnetic resonance imaging (MRI) is required to diagnose NMO. Longitudinally extensive transverse myelitis is NMO’s imaging hallmark and the presence of a brain MRI that is not diagnostic of multiple sclerosis (MS) also remains part of the diagnostic criteria. It is increasingly recognised that MS and NMO brain imaging can, however, have similar appearances but differences do exist: hypothalamic, periaqueductal grey and area postrema lesions implicate NMO whilst cortical, U-fibre or Dawson’s finger lesions are suggestive of MS. The timing of image acquisition, age, ethnicity and aquaporin-4 antibody status are all likely to alter the findings at MRI. This review therefore aims to overview and update the reader on NMO imaging, to provide clinically relevant guidance for diagnosing NMO and differentiating it from MS in order to guide management, and to highlight recent research insights.

Neuromyelitis optica mimicking intramedullary tumor

Neuromyelitis optica (NMO) is considered to be a rarer autoimmune disease than multiple sclerosis. It is very difficult to make a diagnosis of MNO for doctors who are not familiar with its clinical features and diagnostic criteria. We report a case of a young female patient who had been suffering motor weakness and radiating pain in both upper extremities. Cervical MRI showed tumorous lesion in spinal cord and performed surgery to remove lesion. We could not find a tumor mass in operation field and final diagnosis was NMO. NMO must be included in the differential diagnosis of lesions to rescue the patient from invasive surgical interventions. More specific diagnostic tools may be necessary for early diagnosis and proper treatment.

Brain abnormalities in neuromyelitis optica spectrum disorder

Neuromyelitis optica (NMO) is an idiopathic inflammatory syndrome of the central nervous system that is characterized by severe attacks of optic neuritis (ON) and myelitis. Until recently, NMO was considered a disease without brain involvement. However, since the discovery of NMO-IgG/antiaqaporin-4 antibody, the concept of NMO was broadened to NMO spectrum disorder (NMOSD), and brain lesions are commonly recognized. Furthermore, some patients present with brain symptoms as their first manifestation and develop recurrent brain symptoms without ON or myelitis. Brain lesions with characteristic locations and configurations can be helpful in the diagnosis of NMOSD. Due to the growing recognition of brain abnormalities in NMOSD, these have been included in the NMO and NMOSD diagnostic criteria or guidelines. Recent technical developments such as diffusion tensor imaging, MR spectroscopy, and voxel-based morphometry reveal new findings related to brain abnormalities in NMOSD that were not identified using conventional MRI. This paper focuses on the incidence and characteristics of the brain lesions found in NMOSD and the symptoms that they cause. Recent studies using advanced imaging techniques are also introduced.

Meningoencephalitis as an initial manifestation of neuromyelitis optica spectrum disorder

Two patients presented with initial symptoms of headache and fever, and two weeks later had disturbance of consciousness. Cerebrospinal fluid (CSF) showed pleocytosis >500×10²/L. Magnetic resonance imaging (MRI) showed multiple brain lesions at sites of high aquaporin-4 (AQP-4) expression. Case 1 presented optic neuritis four years after the first attack and case 2 had symptoms of myelitis three weeks after headache. Serum AQP-4 antibody was positive in both cases, and the diagnosis of neuromyelitis optica spectrum disorder (NMOSD) was made. Accordingly, NMOSD can initially present as meningoencephalitis mimicking intracranial infection, and the characteristic MRI imaging is quite critical for differentiation.