Brain magnetic resonance imaging abnormalities in neuromyelitis optica

An Autopsy Confirmed Neuromyelitis Optica Spectrum Disorder with Extensive Brain White Matter Lesion and Optic Neuritis but Intact Spinal Cord, Clinically Mimicking a Secondary Progressive Multiple Sclerosis-like Course

A 57-year-old woman presented with optic neuritis with repeated clinical symptoms of focal demyelination of the cerebral white matter and brain stem for 14 years. At the end of the patient's course, the clinical signs mimicked secondary progressive multiple sclerosis, but whether it was caused by interferon administration or neuromyelitis optica spectrum disorders (NMOSD) - or a combination of both or others - was unclear. Histopathological findings indicated the etiology to be NMOSD, with no apparent plaque in spinal cord specimens. This case suggests that an accurate clinical diagnosis requires serum anti-aquaporin 4 antibody measurements as well as an autopsy examination.

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.

Hemorrhagic encephalitis in a patient with neuromyelitis optica: A case report

Context: Neuromyelitis optica (NMO) is a severe, inflammatory, relapsing disease with a predilection for the optic nerves and spinal cord. The manifestations of brain involvement take various forms, but the occurrence of intracerebral hemorrhage is seldom observed.Finding: We report the case of a patient with NMO who presented with hemorrhagic encephalitis during the course of the disease.Conclusion: This case report is the first documented instance of hemorrhagic encephalitis identified in a patient with NMO. Among the manifestations of brain involvement in patients with NMO, hemorrhagic encephalitis is rare but can be observed.

Dementia and Parkinson-like syndrome with basal ganglia lesion in neuromyelitis optica spectrum disorders

Brain lesions in neuromyelitis optica spectrum disorders (NMOSD) are generally located at sites of high anti-aquaporin 4 (AQP4) expression. Clinical features of NMOSD associated with basal ganglia damage in sites not enriched with AQP4 remain unknown. Here we describe the case of an 82-year-old woman who developed dementia and bradykinesia for 5 weeks. Brain magnetic resonance imaging revealed obvious basal ganglia abnormalities. Test for serum anti-AQP4 antibody was positive, and she was diagnosed with NMOSD. Our case showed that NMOSD associated with dementia and/or Parkinson-like syndrome with basal ganglia lesions could be another clinical presentation in NMOSD.

The prevalence of cognitive impairment in patients with neuromyelitis optica spectrum disorders (NMOSD): A systematic review and meta-analysis

OBJECTIVE

To estimate pooled prevalence of cognitive impairment in neuromyelitis opticaspectrum disorders (NMOSD) cases.

METHODS

We searched PubMed, Scopus, EMBASE, Web of Science, and google scholar. We also searched the gray literature including references of the included studies, and conference abstracts which were published up to 20th October 2020. The search strategy included the MeSH and text words as (((Cognitive Dysfunctions) OR Cognitive Impairment) OR Cognitive Declines) OR Mild Cognitive Impairment) OR Mental Deterioration) AND (Neuromyelitis Optica spectrum disorder OR NMOSD OR Devic syndrome OR Neuromyelitis Optica spectrum disorders).

RESULTS

The literature search revealed 1830 articles, after deleting duplicates 1434 remained. For the meta-analysis, 25 studies were included. Totally, 761 NMOSD patients were evaluated and 329 patients had cognitive impairment. Mean age ranged from 34-53 years. The prevalence of cognitive impairment ranged from 3% to 75%.The pooled prevalence of cognitive impairment was 44%, 95%CI(35%-54%), (I²=89.1%, P<0.001) which shows a high statistical heterogeneity . By excluding the abstract of Jung et al which was published in 2009, we found that the pooled prevalence was 34% (95% CI:31-37%) (I²=0) CONCLUSION: Cognitive impairment should be considered in NMOSD patients as its pooled prevalence is estimated as 44%.

MRI Characteristics of NMO, MOG and MS Related Optic Neuritis

Acute isolated optic neuritis can be the initial presentation of demyelinating inflammatory central nervous system disease related to multiple sclerosis (MS), neuromyelitis optica (NMO) or myelin oligodendrocyte glycoprotein antibody disease (MOG-AD). In addition to the well-characterized brain and spinal cord imaging features, important and characteristic differences in the radiologic appearance of the optic nerves in these disorders are being described, and magnetic resonance imaging (MRI) of the optic nerves is becoming an essential tool in the differential diagnosis of optic neuritis. Whereas typical demyelinating optic neuritis is a relatively mild and self-limited disease, atypical optic neuritis in NMO and MOG-AD is potentially much more vision-threatening and merits a different treatment approach. Thus, differentiation based on MRI features may be particularly important during the first attack of optic neuritis, when antibody status is not yet known. This review discusses the optic nerve imaging in the major demyelinating disorders with an emphasis on clinically relevant differences that can help clinicians assess and manage these important neuro-ophthalmic disorders. It also reviews the utility of optic nerve MRI as a prognostic indicator in acute optic neuritis.

Optical Coherence Tomography in Neuromyelitis Optica spectrum disorder and Multiple Sclerosis: A population-based study

BACKGROUND

The aim of this study was to identify and compare the characteristics of retinal nerve layers using spectral domain-optical coherence tomography (SD-OCT) in neuromyelitis optica spectrum disorder (NMOSD), relapsing-remitting multiple sclerosis (RRMS) and healthy controls (HCs).

METHODS

It is a cross-sectional population-based study in Isfahan, Iran. We enrolled 98 participants including 45 NMOSD patients (90 eyes), 35 RRMS patients (70 eyes) and 18 HCs (36 eyes). Evaluation criteria were thickness of different sectors in peripapillary retinal nerve fiber layer (pRNFL) and intra-retinal layers around the macula. History of previous optic neuritis (ON) was obtained through chart review and medical record.

RESULTS

Without considering ON, total macular, ganglion cell layer (GCL) and pRNFL were significantly thinner in both groups of patients compared to HCs. On macular examination, GCL and total macular thickness were significantly thinner than HCs in all NMOSD and RRMS eyes with and without history of ON. While there was no significant difference between MS-ON and MS without a history of ON in the macular measures, the reduction in total macular and GCL thickness was significantly greater in NMOSD-ON compared to NMOSD without a history of ON. Also in NMOSD-ON eyes, the RNFL, GCL, IPL and GCIPL layers were significantly thinner than that of MS-ON. On the other hand, the pRNFL study showed significant thinning of all quadrants in the RRMS and NMOSD groups relative to HCs. While the decrease of pRNFL thickness in the eyes of NMOSD-ON and MS with and without a previous history of ON was significantly greater than that of HCs, no difference was observed between NMOSD without ON and HCs. In addition, in NMOSD patients, pRNFL was significantly thinner in eyes with history of ON compared to non ON-eyes. Furthermore, in patients with a history of ON, reduction in all sectors of pRNFl (except in T) was significantly greater in NMOSD compared to MS patients.

CONCLUSION

Our findings showed that although macular and retinal damage occurred in both NMOSD and RRMS patients without significant differences, the severity of injury in eyes with history of ON was significantly higher in NMOSD compared to MS patients, that could be considered as a marker to distinguish them. In addition, our results confirmed the absence of subclinical optic nerve involvement in NMOSD unlike MS patients.

Radiological characteristics of neuromyelitis optica spectrum disorder in Kuwait

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory demyelinating disorder of the central nervous system that predominantly targets optic nerves and spinal cord. Studies of NMOSD are scarce in the Middle East.

OBJECTIVE

To evaluate the MRI characteristics of NMOSD patients in Kuwait.

PATIENT AND METHODS

This is an observational, retrospective study on NMOSD patients who attended the MS clinic. Patients who fulfilled the 2015 diagnostic criteria of NMOSD were included. Patients` clinical, radiological and serological data were extracted from the medical records. The radiological variables were compared according to gender and AQP4 serostatus.

RESULTS

Forty-two patients fulfilling the NMOSD diagnostic criteria. The mean age and mean age of onset were 32.6 ± 11.4 and 28.9 ± 9.8 years respectively. Females represented 83.3 % of the cohort with female-to-male ratio of 5:1. Thirty-one patients (73.8 %) tested positive for AQP4 antibody. Nineteen patients (45.2 %) had bilateral optic nerve involvement, while chiasmal involvement was seen in 8 (19.0 %) patients. Spinal cord was involved in 36 (85.7 %) patients; of whom 27 (64.3 %) had LETM. The most common spinal segment involved was the cervical (72.2 %) followed by the dorsal (25.0 %) regions. The brain was involved in 39 (92.8 %) patients and the periventricular region around fourth and lateral ventricles was the most commonly involved site (n = 35; 83.3 %), along with periaqueductal (n = 25; 61.9 %) and corpus callosal (n = 24; 57.1 %) regions. Isolated area postrema involvement was observed in 9 (21.4 %) patients.

CONCLUSION

This is the first study describing the radiological characteristics of NMOSD in Kuwait. Although our data is comparable with the previous international studies, a higher percentage of bilateral optic nerve, brain, and callosal involvement was observed. Further multicenter studies with a larger cohort are needed to confirm our results.

CNS inflammatory demyelinating disorders: MS, NMOSD and MOG antibody associated disease

Although Multiple Sclerosis is the most common central nervous system (CNS) inflammatory demyelinating disorder, other CNS inflammatory disorders should be included as diagnostic considerations. Neuromyelitis Optica Spectrum Disorder (NMOSD) and myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease are less common but share some clinical characteristics, such as optic neuritis and myelitis, which can make a specific diagnosis challenging. However, these disorders have distinctive and generally different clinical phenotypes, prognosis and management. It is imperative to distinguish each from one another, especially since the treatments (not discussed in this review) can be different. The advent of reliable testing for anti-aquaporin-4 for NMOSD and anti-MOG antibodies has helped significantly; however, diagnosis can remain challenging, especially in sero-negative cases. Clinical indicators are important to guide diagnostic work-up. Careful review of the history, neurological exam, imaging, and/or spinal fluid results are essential to making an accurate diagnosis. In this review, we will examine the clinical presentation, diagnosis, and natural history of these inflammatory CNS disorders.

Disruption of blood-brain barrier integrity associated with brain lesions in Chinese neuromyelitis optica spectrum disorder patients

OBJECTIVE

The aims of this study were to report brain characteristic abnormalities and to evaluate the relationship of blood-brain barrier (BBB) disruption and brain lesions in Chinese patients with NMOSD.

METHODS

Brain magnetic resonance imaging characteristics and cerebrospinal fluid (CSF) laboratory tests of 121 patients with NMOSD at acute attack were reviewed retrospectively. Qalb (CSF albumin/serum albumin) was used for assessment of disruption of BBB.

RESULTS

Brain MRI abnormalities were observed in 36.4% (44/121) of the NMOSD patients. Thirty patients (25%) showed typical-NMOSD abnormalities, including dorsal medulla lesions (n = 16, 13.2%), brainstem/cerebellum (n = 11, 9.1%), thalamus/hypothalamus (n = 3, 2.5%), periventricular white matter lesions (n = 4, 3.3%) hemispheric white matter (n = 4, 3.3%). Twenty-five patients (20.7%) had nonspecific lesions. Compared to the NMOSD patients without brain lesion, the proportion of patients who had abnormal BBB permeability was significantly higher in the abnormal brain MRI group (47.7% vs. 27.3%, P < 0.05). BBB permeability was not correlated to distribution of brain lesions or enhancement lesions. Qalb was associated with higher Expanded Disability Status Scale scores (r = 0.689, P < 0.05).

CONCLUSIONS

Brain lesions are common in NMOSD patients. Marker of BBB permeability is associated with brain lesion and EDSS scores of NMOSD.

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.

Cervical cord and ventricle affection in neuromyelitis optica

OBJECTIVES

Cervical cord involvement is common in neuromyelitis optica (NMO) and multiple sclerosis (MS), but its impact on disability in NMO has rarely been studied. Recent publications on NMO examined the periventricular system, areas of high aquaporin-4 expression, but not yet by using ventricle volumetry.

PURPOSE

To compare cervical cord atrophy, ventricular widening, and supra- and infratentorial brain measures between NMO and MS, and study their impact on clinical disability.

METHODS

Magnet resonance imaging-based volumetry of upper cervical cord, third and fourth lateral ventricles, grey matter, white matter, brainstem, cerebellum and clinical status of 18 NMO and 20 MS patients, was compared between the groups and with 26 healthy controls. Patterns of ventricular widening relative to healthy controls were inspected by voxel-based morphometry of the cerebrospinal fluid.

RESULTS

Cervical cord atrophy was similar in NMO and MS (75.2 ± 10.0 mm² , respectively, 76.5 ± 9.5 mm² vs 84.1 ± 8.6 mm² in controls).Third ventricle increase in both groups, and specific fourth ventricle widening in MS were detected. Patient groups differed in third to fourth ventricle ratio (P = 0.002). In NMO, white matter correlated inversely with the affected cord segments (P = 0.001) and with cervical cord area (P = 0.043). The disability status was explained by cervical cord area and third ventricle volume (R² =0.524) in NMO, and by grey matter and fourth ventricle volume (R² =0.565) in MS.

CONCLUSION

Cervical cord atrophy and third ventricular enlargement are both clinically relevant in NMO. Third and fourth ventricle volumetry shows differences between NMO and MS regarding the involvement of periventricular structures.

Magnetic resonance imaging brain findings in a case of aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder, presenting with intractable vomiting and hiccups

Neuromyelitisoptica (NMO) and multiple sclerosis (MS) were once considered to be differing manifestation of same auto immune disease, NMO predominantly involving the optic nerve and cord. Now with discovery of NMO antibody the concept has changed and a spectrum of disorders with lesions in brain has been identified. Occasionally, brain may be the first or the only site of involvement in these disorders hence it is essential to be aware of this spectrum. The brain lesions in NMO/NMOSD may be located in characteristic regions and present with symptoms mimicking non neurological disease. We herein present a case of an adult female who was admitted with intractable vomiting and hiccups; subsequently on MRI brain found to have very tiny demyelinating foci in Area Postrema.

Quantitative Susceptibility Mapping Indicates a Disturbed Brain Iron Homeostasis in Neuromyelitis Optica - A Pilot Study

Dysregulation of brain iron homeostasis is a hallmark of many neurodegenerative diseases and can be associated with oxidative stress. The objective of this study was to investigate brain iron in patients with Neuromyelitis Optica (NMO) using quantitative susceptibility mapping (QSM), a quantitative iron-sensitive MRI technique. 12 clinically confirmed NMO patients (6 female and 6 male; age 35.4y±14.2y) and 12 age- and sex-matched healthy controls (7 female and 5 male; age 33.9±11.3y) underwent MRI of the brain at 3 Tesla. Quantitative maps of the effective transverse relaxation rate (R2*) and magnetic susceptibility were calculated and a blinded ROI-based group comparison analysis was performed. Normality of the data and differences between patients and controls were tested by Kolmogorov-Smirnov and t-test, respectively. Correlation with age was studied using Spearman's rank correlation and an ANCOVA-like analysis. Magnetic susceptibility values were decreased in the red nucleus (p<0.01; d>0.95; between -15 and -22 ppb depending on reference region) with a trend toward increasing differences with age. R2* revealed significantly decreased relaxation in the optic radiations of five of the 12 patients (p<0.0001; -3.136±0.567 s(-1)). Decreased relaxation in the optic radiation is indicative for demyelination, which is in line with previous findings. Decreased magnetic susceptibility in the red nucleus is indicative for a lower brain iron concentration, a chemical redistribution of iron into less magnetic forms, or both. Further investigations are necessary to elucidate the pathological cause or consequence of this finding.

Dynamic change in magnetic resonance imaging of patients with neuromyelitis optica

OBJECTIVE

To analyze changes in magnetic resonance imaging (MRI) of spinal cord lesions in neuromyelitis optica (NMO) and the correlation between segmental length of spinal cord lesions and expanded disability status scale (EDSS) scores.

METHODS

Twenty-five patients with confirmed NMO were examined from the Second Affiliated Hospital of Guangzhou Medical University, China. The information collected included their treatment, MRI, laboratory tests, and EDSS scores at different stages.

RESULTS

All cases exhibited spinal cord lesions, with 23 (92%) having longitudinally extensive transverse myelitis (extending ≥3 vertebral segments). There was a positive correlation between segmental length of spinal cord lesions and EDSS scores: during the acute phase, r = 0.430 (P = 0.032); during remission, r = 0.605 (P = 0.002). Enlarged spinal cord lesions and swelling were found in 18 cases (72%) during the acute phase, and 4 cases (16%, P = 0.000) after 6 months of treatment. Lesion enhancements were found in 17 cases (68%) during the acute phase, and 8 cases (32%, P = 0.023) after 6 months of treatment. Leptomeningeal enhancement was found in three cases during the acute phase, which disappeared after treatment. Atrophy of spinal cord lesions occurred in two cases. Change in lesions was statistically significant (P = 0.006) after 12 months of treatment.

CONCLUSION

Positive correlation was found between segmental length of spinal cord lesions and EDSS scores, which was more significant during remission. After 6 months of regular treatment, restorative changes compared with the acute phase were found by MRI.

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

BACKGROUND

Recognizing the cause of optic neuritis (ON) affects treatment decisions and visual outcomes.

OBJECTIVE

We aimed to define radiological features of first-episode demyelinating ON.

METHODS

We performed blinded radiological assessment of 50 patients presenting with first-episode myelin oligodendrocyte glycoprotein (MOG) antibody-associated ON (MOG-ON; n=19), aquaporin-4 (AQP4) antibody-associated ON (AQP4-ON; n=11), multiple sclerosis (MS)-associated ON (MS-ON; n=13), and unclassified ON (n=7).

RESULTS

Bilateral involvement was more common in MOG-ON and AQP4-ON than MS-ON (84% vs. 82% vs. 23%), optic nerve head swelling was more common in MOG-ON (53% vs. 9% vs. 0%), chiasmal involvement was more common in AQP4-ON (5% vs. 64% vs. 15%), and bilateral optic tract involvement was more common in AQP4-ON (0% vs. 45% vs. 0%). Retrobulbar involvement was more common in MOG-ON, whereas intracranial involvement was more common in AQP4-ON. MOG-ON and AQP4-ON had longer lesion lengths than MS-ON. The combination of two predictors, the absence of magnetic resonance imaging brain abnormalities and a higher lesion extent score, showed a good ability to discriminate between an autoantibody-associated ON (MOG or AQP4) and MS. AQP4-ON more frequently had severe and sustained visual impairment.

CONCLUSION

MOG-ON and AQP4-ON are more commonly bilateral and longitudinally extensive. MOG-ON tends to involve the anterior optic pathway, whereas AQP4-ON the posterior optic pathway.

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.

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.

In vivo assessment of white matter damage in neuromyelitis optica: a diffusion tensor and diffusion kurtosis MR imaging study

BACKGROUND AND PURPOSE

In patients with neuromyelitis optica (NMO), damage to extensive regions of normal-appearing WM has been observed. To investigate the possibility that microstructural alterations are present in these WM tracts, DTI and diffusion kurtosis imaging (DKI) techniques were applied and compared.

MATERIAL AND METHODS

Thirteen patients with NMO and 13 demographically and gender-matched controls underwent MRI using a 3T MR scanner, with DTI/DKI sequence acquired jointly fitted. Parametric fractional anisotropy maps were derived from diffusion tensor (FADTI) values using b-values of 0s/mm(2) and 1000s/mm(2). Parametric fractional anisotropy maps derived from diffusion kurtosis tensor (FADKI) values were also acquired using b-values of 0, 1000, and 2000s/mm(2). Mean FADTI and FADKI values were also calculated. A ROI analysis of the genu and splenium of the corpus callosum (CC), cerebral peduncle (CP), and optic radiation (OR) was also performed. Student's t-test and corrections for multiple comparisons were used to evaluate the data obtained.

RESULTS

A significant decrease in the FADTI values obtained for NMO patients versus controls was observed for the splenium of the CC and the left OR (p<0.05). However, just a positive trend was observed for the FADKI values associated with the same WM tracts.

CONCLUSIONS

To our knowledge, this is the first study to analyze WM tracts of NMO patients using DTI and DKI. These data indicate that DKI could have limitations in evaluating the WM integrity in NMO patients. Furthermore, the results obtained are consistent with the hypothesis that diffuse brain involvement characterizes NMO.

Neuro-ophthalmologic manifestations of systemic lupus erythematosus: a systematic review

Herein we summarize the clinical presentation, treatment and outcome of neuro-ophthalmologic manifestations in patients with systemic lupus erythematosus (SLE). We performed a systematic review of the neuro-ophthalmologic manifestations of SLE reported in the English literature from 1970 to 2010 by a Medline search. The prevalence of neuro-ophthalmologic manifestations is 3.6% in adult and 1.6% in childhood SLE patients. Neuro-ophthalmologic manifestations of SLE are highly variable, with the commonest presentation being optic neuritis, followed by myasthenia gravis, visual field defects and pseudotumor cerebri. The underlying pathology was thought to be either SLE activity or its vascular complications. Most neuro-ophthalmologic manifestations of SLE are responsive to high-dose glucocorticoids. Anticoagulation is indicated when there is concomitant antiphospholipid syndrome. SLE-related neuromyelitis optica is often refractory to treatment and 92% of patients require multiple immunosuppressive protocols. Neuro-ophthalmologic manifestations of SLE are uncommon but heterogeneous. The prognosis of neuro-ophthalmologic manifestations in SLE is generally good because of their rapid response to glucocorticoids. Relapses of these manifestations may be reduced by the use of maintenance immunosuppression. Cyclophosphamide, azathioprine, plasmapheresis, intravenous immunoglobulin and rituximab can be considered in glucocorticoid-dependent or refractory cases. Anticoagulation is indicated when there is concomitant antiphospholipid syndrome.

Optic neuritis in neuromyelitis optica

Neuromyelitis optica (NMO) is an autoimmune demyelinating disease associated with recurrent episodes of optic neuritis and transverse myelitis, often resulting in permanent blindness and/or paralysis. The discovery of autoantibodies (AQP4-IgG) that target aquaporin-4 (AQP4) has accelerated our understanding of the cellular mechanisms driving NMO pathogenesis. AQP4 is a bidirectional water channel expressed on the plasma membranes of astrocytes, retinal Müller cells, skeletal muscle, and some epithelial cells in kidney, lung and the gastrointestinal tract. AQP4 tetramers form regular supramolecular assemblies at the cell plasma membrane called orthogonal arrays of particles. The pathological features of NMO include perivascular deposition of immunoglobulin and activated complement, loss of astrocytic AQP4, inflammatory infiltration with granulocyte and macrophage accumulation, and demyelination with axon loss. Current evidence supports a causative role of AQP4-IgG in NMO, in which binding of AQP4-IgG to AQP4 orthogonal arrays on astrocytes initiates complement-dependent and antibody-dependent cell-mediated cytotoxicity and inflammation. Immunosuppression and plasma exchange are the mainstays of therapy for NMO optic neuritis. Novel therapeutics targeting specific steps in NMO pathogenesis are entering the development pipeline, including blockers of AQP4-IgG binding to AQP4 and inhibitors of granulocyte function. However, much work remains in understanding the unique susceptibility of the optic nerves in NMO, in developing animal models of NMO optic neuritis, and in improving therapies to preserve vision.

Central nervous system inflammatory demyelinating disorders among Hong Kong Chinese

Classical multiple sclerosis (CMS) and neuromyelitis optica spectrum disorders (NMOSD) are distinct central nervous system inflammatory demyelinating disorders (CNS IDD). Early diagnosis of CNS IDD is important as appropriate immunotherapies to optimize prognosis. We studied the diagnoses of CNS IDD among Hong Kong Chinese in a hospital-based setting. Consecutive Chinese patients who presented to our hospital with clinically isolated syndrome and subsequently diagnosed to have CNS IDD from 1980 to 2010 were reviewed. Patients with known diagnosis of CNS IDD referred for further care were excluded. Serial sera were assayed for aquaporin-4 autoantibodies (AQP4 Ab), at least 3 assays within 2-5years. A total of 210 patients diagnosed to have CNS IDD with disease duration of at least 2years were studied. Among 198 patients with serial sera available, 40 (20.2%, 20 had NMO and 20 other NMOSD) were AQP4 Ab-positive. Four patients who were AQP4 Ab-negative on the initial assay converted to AQP4 Ab-positive on repeated assays. The diagnoses of 210 patients were CMS in 88 (41.9%), NMOSD 47 (22.4%, 27 NMO, 20 other NMOSD), single attack of myelitis 23 (11.0%), single attack of optic neuritis 21 (10.0%), relapsing myelitis 10 (4.8%), acute disseminated encephalomyelitis (ADEM) 9 (4.3%), relapsing optic neuritis in 6 (2.9%), opticospinal multiple sclerosis 3 (1.4%) and single attack of brainstem encephalitis 3 (1.4%). Compared to CMS, NMOSD patients had older onset age, lower frequencies of brain MRI abnormalities and CSF OCB, higher frequency of LETM, higher CNS inflammation attack frequency in the first 2years, worse clinical outcome with higher EDSS score and mortality rate. This hospital-based study suggests that CMS (41.9%) and NMOSD (22.4%) are the most common CNS IDD among Hong Kong Chinese. NMOSD has worse clinical outcome than CMS. Detection of AQP4 Ab facilitates early diagnosis and prompts immunotherapies of NMOSD.

Neuromyelitis optica lesions may inform multiple sclerosis heterogeneity debate

OBJECTIVE

Neuromyelitis optica (NMO) and multiple sclerosis (MS) are considered inflammatory demyelinating diseases with distinguishing pathological characteristics. NMO pathology shows perivascular immunoglobulin G and complement deposition, as well as an astrocytopathy with aquaporin-4 (AQP4) loss. MS lesions reveal a profound, interindividual heterogeneity in immunopathological patterns of active demyelination, which has been challenged by the description of stage-dependent sequences of pathological features. The aim of our study was to compare the histological characteristics of early active demyelinating NMO and MS brain lesions.

METHODS

Thirteen cases with supraspinal active demyelinating NMO lesions were analyzed using immunohistochemistry. Results were compared with the published characteristics of MS lesions.

RESULTS

A subset of supraspinal lesions from AQP4-IgG-seropositive NMO patients revealed both (1) complement activation products within macrophages at sites of active demyelination and (2) oligodendrocyte apoptosis and a preferential loss of myelin-associated glycoprotein. These characteristics resemble features previously associated with MS lesion patterns II and III, and were present in addition to characteristic histopathological NMO features, namely loss of AQP4 and astrocytes.

INTERPRETATION

Early active demyelinating NMO lesions may show complement within macrophages and oligodendrocyte apoptosis associated with a selective loss of minor myelin proteins, in addition to typical NMO features. We hypothesize these findings occur simultaneously only in a subset of active demyelinating NMO lesions. These observations plausibly explain the findings of Barnett and Prineas and further support the concept of interindividual heterogeneity in MS.

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.

Neuromyelitis optica

Neuromyelitis optica (NMO) is a disabling inflammatory condition that targets astrocytes in the optic nerves and spinal cord. Neuro-ophthalmologists must be particularly aware of this disorder because about half of patients present as isolated unilateral optic neuritis months or years before a disease-defining and often crippling bout of myelitis. NMO is easily confused with multiple sclerosis because it is characterized by relapses that lead to stepwise accrual of deficits. The best predictor of conversion from optic neuritis to clinical definite NMO is the presence of a serum antibody to aquaporin-4 called NMO-IgG. However, this test is currently only about 75% sensitive. Suspicion of NMO should be high in patients who present with vision of light perception or worse or who are left with acuity of 20/50 or worse after optic neuritis and in those with simultaneous bilateral optic neuritis or recurrent attacks. Acute NMO relapses are generally treated with high-dose intravenous steroids, with plasma exchange often used as a rescue therapy for those who do not respond. Preventative strategies against relapses currently use broad-spectrum or selective B-lymphocyte immune suppression, but their use is based on small, generally uncontrolled studies. Hopefully, the future will bring more sensitive tools for defining risk and predicting outcome, as well as more targeted and effective forms of therapy.

Diagnostic approach of patients with longitudinally extensive transverse myelitis

The aim of this study is to present a diagnostic and therapeutic approach in patients with LETM. In a period between June 2008 and June 2010, all patients who fulfilled criteria for LETM were included in the study. All patients underwent a standardized protocol of investigations presented in this paper. Ten patients were included (5 male, 5 female, with the age distribution from 24 to 70 years). Four patients were diagnosed with NMO/spatially limited NMO spectrum disorder, three patients were diagnosed with spinal cord ADEM, two multiple sclerosis (MS) and one patient with copper deficiency myelopathy. Laboratory support for the diagnosis of NMO was positive NMO-IgG antibody; for the diagnosis of ADEM signs of peripheral nervous system involvement on electromyoneurography; and for the diagnosis of MS brain MRI lesions typical for MS, as well as positive oligoclonal bands (OCB) in the cerebrospinal fluid (CSF). All cases with inflammatory myelopathy were treated either with steroids or plasma exchange and copper replacement was started in the case of copper deficiency. The mean time from the first symptom until the final diagnosis was 16.3 months (range 1 month to 7 years). As each of idiopathic inflammatory demyelinating diseases that can present with LETM have specific therapy, the postponement in making the correct diagnosis can lead to a poor recovery. In patients with LETM, a standardized diagnostic approach can result in a correct diagnosis and appropriate treatment.

Neuromyelitis optica: an antibody-mediated disorder of the central nervous system

Neuromyelitis optica (NMO) is a recurrent inflammatory disease that preferentially targets the optic nerves and spinal cord leading to blindness and paralysis. The hallmarks of NMO include bilateral optic neuritis and longitudinally extensive transverse myelitis. Woman and African Americans are overrepresented in the US patient population. NMO is associated with the NMO-IgG biomarker, which targets the aquaporin-4 water channel on astrocytes. The humoral pathology of NMO lesions include IgG and IgM deposits and infiltration by granulocytes suggesting that the NMO-IgG may be involved in the pathogenesis of disease. This review of the recent NMO literature covers the clinical features, epidemiology, radiology and pathology of disease and includes discussion of the important basic science research work in the field.

Pencil-thin ependymal enhancement in neuromyelitis optica spectrum disorders

AQP4 water channels are thought to be the target of autoimmune attack in neuromyelitis optica-spectrum disorders (NMOsd). AQP4 are highly expressed on ventricular ependyma. The objective of this study was to describe a novel pattern of linear, 'pencil-thin' enhancement of ventricular ependyma in NMOsd. We report two NMOsd patients with pencil-thin ependymal enhancement along the frontal and occipital horns of lateral ventricles. Differential diagnosis of ependymal enhancement should include NMOsd alongside with infectious and neoplastic etiologies. Pencil-thin ependymal enhancement may be a helpful radiological marker of NMOsd that can be used to differentiate this condition from multiple sclerosis.

New insights into neuromyelitis optica

Neuromyelitis optica (NMO) is an idiopathic inflammatory disorder of the central nervous system (CNS) that preferentially affects the optic nerves and spinal cord. In Asia, NMO has long been considered a subtype of multiple sclerosis (MS). However, recent clinical, pathological, immunological, and imaging studies have suggested that NMO is distinct from MS. This reconsideration of NMO was initially prompted by the discovery of a specific antibody for NMO (NMO-IgG) in 2004. NMO-IgG is an autoantibody that targets aquaporin-4 (AQP4), the most abundant water channel in the CNS; hence, it was named anti-AQP4 antibody. Since it demonstrated reasonable sensitivity and high specificity, anti-AQP4 antibody was incorporated into new diagnostic criteria for NMO.The spectrum of NMO is now known to be wider than was previously recognized and includes a proportion of patients with recurrent, isolated, longitudinally extensive myelitis or optic neuritis, and longitudinally extensive myelitis or optic neuritis associated with systemic autoimmune disease or with brain lesions typical of NMO. In this context, a new concept of "NMO spectrum disorders" was recently introduced. Furthermore, seropositivity for NMO-IgG predicts future relapses and is recognized as a prognostic marker for NMO spectrum disorders. Humoral immune mechanisms, including the activation of B-cells and the complement pathway, are considered to play important roles in NMO pathogenesis. This notion is supported by recent studies showing the potential pathogenic role of NMO-IgG as an initiator of NMO lesions. However, a demonstration of the involvement of NMO-IgG by the development of active immunization and passive transfer in animal models is still needed. This review focuses on the new concepts of NMO based on its pathophysiology and clinical characteristics. Potential management strategies for NMO in light of its pathomechanism are also discussed.

Comparative brain stem lesions on MRI of acute disseminated encephalomyelitis, neuromyelitis optica, and multiple sclerosis

Background

Brain stem lesions are common in patients with acute disseminated encephalomyelitis (ADEM), neuromyelitis optica (NMO), and multiple sclerosis (MS).

Objectives

To investigate comparative brain stem lesions on magnetic resonance imaging (MRI) among adult patients with ADEM, NMO, and MS.

Methods

Sixty-five adult patients with ADEM (n = 17), NMO (n = 23), and MS (n = 25) who had brain stem lesions on MRI were enrolled. Morphological features of brain stem lesions among these diseases were assessed.

Results

Patients with ADEM had a higher frequency of midbrain lesions than did patients with NMO (94.1% vs. 17.4%, P<0.001) and MS (94.1% vs. 40.0%, P<0.001); patients with NMO had a lower frequency of pons lesions than did patients with MS (34.8% vs. 84.0%, P<0.001) and ADEM (34.8% vs. 70.6%, P = 0.025); and patients with NMO had a higher frequency of medulla oblongata lesions than did patients with ADEM (91.3% vs. 35.3%, P<0.001) and MS (91.3% vs. 36.0%, P<0.001). On the axial section of the brain stem, the majority (82.4%) of patients with ADEM showed lesions on the ventral part; the brain stem lesions in patients with NMO were typically located in the dorsal part (91.3%); and lesions in patients with MS were found in both the ventral (44.0%) and dorsal (56.0%) parts. The lesions in patients with ADEM (100%) and NMO (91.3%) had poorly defined margins, while lesions of patients with MS (76.0%) had well defined margins. Brain stem lesions in patients with ADEM were usually bilateral and symmetrical (82.4%), while lesions in patients with NMO (87.0%) and MS (92.0%) were asymmetrical or unilateral.

Conclusions

Brain stem lesions showed various morphological features among adult patients with ADEM, NMO, and MS. The different lesion locations may be helpful in distinguishing these diseases.

Cognitive impairment and whole brain diffusion in patients with neuromyelitis optica after acute relapse

The objective of this study investigated cognitive impairments and their correlations with fractional anisotropy (FA) and mean diffusivity (MD) in patients with neuromyelitis optica (NMO) without visible lesions on conventional brain MRI during acute relapse. Twenty one patients with NMO and 21 normal control subjects received several cognitive tests to assess cognitive function. Head diffusion tensor imaging (DTI) of all patients with NMO were collected with a 3-T MR system. Correlations of cognitive test scores and whole brain FA and MD were examined by voxel-based analysis. Region-of-interest analysis was applied to the significantly correlated regions which the most frequently appeared. We found that NMO patients without visible brain lesions had significantly impaired learning and memory, decreased information processing speed, and damaged attention compared with normal control subjects. These impaired cognitive domains were significantly correlated with FA and MD in local regions of corpus callosum, anterior cingulate and medial frontal cortex. In corpus callosum of NMO patients, mean FA was significantly lower and mean MD higher than normal control subjects. Our findings suggest that cognitive impairments in learning and memory, information processing speed and attention occur in NMO patients without visible brain lesions during acute relapse. The impairments in immediate and short-term memory in NMO patients may be due to information encoding deficits in the process of information acquisition. The corpus callosum of such patients may have local microscopic damages that play a role in cognitive impairments during acute relapse.