Comparison of deep gray matter lesions on magnetic resonance imaging among adults with acute disseminated encephalomyelitis, multiple sclerosis, and neuromyelitis optica

A comparative study of hypothalamic involvement in patients with myelin oligodendrocyte glycoprotein antibody-associated disease, neuromyelitis optica spectrum disorder, and multiple sclerosis

BACKGROUND AND PURPOSE

We aimed to characterize hypothalamic involvement in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and compare it with neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS).

METHODS

A retrospective study was performed to identify hypothalamic lesions in patients diagnosed with MOGAD, NMOSD, or MS from January 2013 to May 2020. The demographic, clinical, and radiological features were recorded. Hypothalamic dysfunction and prognosis were assessed through physical examination, biochemical testing, sleep monitoring, and magnetic resonance imaging.

RESULTS

Hypothalamic lesions were observed in seven of 96 patients (7.3%) with MOGAD, 34 of 536 (6.3%) with NMOSD, and 16 of 356 (4.5%) with MS (p = 0.407). The time from disease onset to development of hypothalamic lesions was shortest in MOGAD (12 months). The frequency of bilateral hypothalamic lesions was the lowest in MOGAD (p = 0.008). The rate of hypothalamic dysfunction in MOGAD was 28.6%, which was lower than that in NMOSD (70.6%) but greater than that in MS patients (18.8%; p = 0.095 and p = 0.349, respectively). Hypothalamic dysfunction in MOGAD manifests as hypothalamic-pituitary-adrenal axis dysfunction and hypersomnia. The proportion of complete regression of hypothalamic lesions in MOGAD (100%) was much greater than that in NMOSD (41.7%) and MS patients (18.2%; p = 0.007 and p = 0.001, respectively). An improvement in hypothalamic dysfunction was observed in all MOGAD patients after immunotherapy.

CONCLUSIONS

MOGAD patients have a relatively high incidence of asymptomatic hypothalamic lesions. The overall prognosis of patients with hypothalamic involvement is good in MOGAD, as the lesions completely resolve, and dysfunction improves after immunotherapy.

Patterns of Adult Neuromyelitis Optica Spectrum Disorder Patients Compared to Multiple Sclerosis: A Systematic Review and Meta-Analysis

Neuromyelitis optica spectrum disorders (NMOSDs) are central nervous system inflammatory conditions, now recognized to involve the brain, often identified by aquaporin-4 (AQP4) antibodies. We aimed to summarize the characteristics of adult NMOSD patients compared to multiple sclerosis (MS). A computerized search was conducted on MEDLINE via PubMed, Web of Science, and ProQuest using the relevant keywords. Three independent reviewers performed two-stage screening and data extraction. The Review Manager 5.4 program (Cochrane Collaboration, Windows, London, UK) was used for the analysis. The Joanna Briggs Institute (JIB) tool was used for the quality of included studies. Twenty-three articles were included. NMOSD patients were associated with older age at presentation and higher Expanded Disability Status Scale (MD = 3.88, 95% CI: 1.80 to 5.97, P = 0.0003) and (MD = 1.15, 95% CI: 0.58 to 1.72, P < 0.0001), respectively. The risk of NMOSD in females was significantly higher than MS (OR = 2.21, 95% CI: 1.41 to 3.46, P = 0.0005). Patients with NMOSD were associated with a lower risk of extrapyramidal symptoms (OR = 0.26, 95% CI: 0.11 to 0.60, P < 0.01), brainstem involvement symptoms (OR = 0.32, 95% CI: 0.16 to 0.64, P < 0.01), and developing brain lesions compared to MS (OR = 0.08, 95% CI: 0.03 to 0.18, P < 0.00001). The current evidence suggests that both NMOSD and MS have different demographic, clinical, and lesion characteristics. There is a need for additional validation of the identified differences compared with MS due to the lack of long-term systematic imaging investigations in NMOSD.

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.

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.

Hypothalamic lesions in neuromyelitis optica spectrum disorders: exploring a scoring system based on magnetic resonance imaging

PURPOSE

We propose a scoring system for early diagnosis of sleep abnormalities in neuromyelitis optica spectrum disorders (NMOSD) with hypothalamic lesions based on magnetic resonance imaging (MRI).

MATERIALS AND METHODS

We evaluated MRI features of 45 patients with hypothalamic lesions identified from two cohorts. Univariate logistic regression analysis identified factors associated with sleepiness, which were subsequently used to develop a scoring system. Interrater reliability was determined using intraclass correlation coefficient (ICC). Correlations between scores and clinical features were analyzed.

RESULTS

In total, 48.9% of 45 patients with hypothalamic lesions exhibited sleepiness. The number of involved slices, maximum width/length of hypothalamic lesions, and boundaries extending beyond the hypothalamus were associated with sleepiness (all p < 0.05). The sensitivity and specificity of the scoring system were 68.2% and 87.0%, respectively. The ICC values for the maximum width and length measurement of hypothalamic lesions were 0.82 and 0.81, respectively. Daily sleep time and Epworth sleepiness scale scores were positively correlated with MRI-based scores (p < 0.05, 95% confidence interval (CI) 0.69-0.93 and p < 0.05, 95% CI 0.55-0.88, respectively).

CONCLUSION

A scoring system based on MRI features was developed to provide diagnosis of sleepiness in NMOSD with hypothalamic lesions earlier than other measures.

Diagnostic and therapeutic issues of inflammatory diseases of the elderly

Inflammatory diseases of the central nervous system (CNS) mainly occur during early adulthood and multiple sclerosis (MS) represents the overwhelming majority of these disorders. Nevertheless, MS only rarely begins after 50 years and a diagnosis of late-onset MS should only be done when clinical as well as radiological and biological findings are typical of MS since the probability of misdiagnosis is higher in elderly patients. Indeed, in patients aged over 50 years, along with a relative decrease of MS incidence, other inflammatory diseases of the CNS but also differential diagnoses including neoplastic as well as infectious disorders should be thoroughly searched to avoid diagnostic mistakes and the prescription of inadequate and potentially harmful immunomodulatory/immunosuppressive therapies. Moreover, aging is associated with diverse immune changes also known as immunosenescence resulting in, notably, higher risk of comorbidities (including vascular diseases) and infections which need to be considered when planning medical treatments of elderly patients with inflammatory diseases of the CNS. Herein, therapeutic and diagnostic challenges faced by neurologists are reviewed to ease patient management.

[A case of suspected neuromyelitis optica spectrum disorder preceded by aseptic meningitis-like symptoms]

A 20-year-old woman was hospitalized after experiencing headaches, high fever, and nausea for 1 week. She was conscious and had no abnormal neurological findings or neck stiffness. Examination of her cerebrospinal fluid showed a pronounced elevation of mononuclear cells. She was admitted to our hospital with the diagnosis of meningitis and had hypersomnia 3 days later. Brain MRI (FLAIR) demonstrated high-intensity lesions at the dorsal pons, and bilateral hypothalamus and spinal MRI demonstrated longitudinal T₂ high-intensity lesions extending from C2 to C4 and from C6 to Th6. We suspected neuromyelitis optica spectrum disorder (NMOSD) and administered intravenous methylprednisolone after which her symptoms and MRI abnormalities improved immediately. Serum anti-aquaporin-4 antibody and anti-myelin oligodendrocyte glycoprotein antibody were negative. Thus, it is important to perform MRI imaging early in the onset of aseptic meningitis due to numerous case reports of patients diagnosed with neuromyelitis optica or NMOSD with initial meningitis-like symptoms.

Acute disseminated encephalomyelitis following varicella-zoster virus infection: Case report of effective treated both in clinical symptom and neuroimaging

INTRODUCTION

Acute disseminated encephalomyelitis (ADEM) is an idiopathic inflammatory demyelinating disorder of the central nervous system (CNS). Early treatment is the key for neurological recovery.

METHODS

A case of ADEM associated with varicella-zoster virus infection was presented, in which magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) examinations were included.

RESULTS

Magnetic resonance imaging of the brain revealed multiple hyperintense lesions at the subcortical level on fluid-attenuated inversion recovery (FLAIR), and MRI of the spinal cord revealed longitudinally segmented hyperintense lesions at the spinal cord on T2-weighted images. The patient was treated with methylprednisolone and gancyclovir, and had a favorable recovery. Subsequent MRI of the brain and cervical cord showed the previous abnormal hyperintensities had markedly disappeared.

CONCLUSION

A rare case of ADEM with longitudinal segmented hyperintense lesions at the spinal cord on T2-weighted images was presented. Excellent response to ADEM treatment with high-dose steroids was reported resulting in a remarkable neurological recovery. A long-term follow-up is needed for prognosis.

Atypical inflammatory demyelinating lesions and atypical multiple sclerosis

Atypical idiopathic inflammatory demyelinating disorders (IIDDs) of the brain have long been known to be disorders closely related to multiple sclerosis (MS), despite having distinctive clinical and radiological characteristics. Originally, they mostly corresponded to acute-onset variants of MS that classically had poor prognoses, such as Baló's concentric sclerosis, Marburg variant of MS and Schilder's disease, and their relationship with MS was based on their shared pathological findings and the co-occurrence of these variants in patients with typical MS. More recently, other atypical disorders, such as solitary sclerosis, have also been described as belonging to the MS spectrum, raising the question of their links with MS. Meanwhile, multiple MS mimics have been described and need to be considered in the differential diagnosis of MS. In addition, thorough characterization of these atypical entities, including advanced MRI and biological studies, is now warranted to further improve their management.

Differential diagnosis of neuromyelitis optica spectrum disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disorder of the central nervous system (CNS) mostly manifesting as optic neuritis and/or myelitis, which are frequently recurrent/bilateral or longitudinally extensive, respectively. As the autoantibody to aquaporin-4 (AQP4-Ab) can mediate the pathogenesis of NMOSD, testing for the AQP4-Ab in serum of patients can play a crucial role in diagnosing NMOSD. Nevertheless, the differential diagnosis of NMOSD in clinical practice is often challenging despite the phenotypical and serological characteristics of the disease because: (1) diverse diseases with autoimmune, vascular, infectious, or neoplastic etiologies can mimic these phenotypes of NMOSD; (2) patients with NMOSD may only have limited clinical manifestations, especially in their early disease stages; (3) test results for AQP4-Ab can be affected by several factors such as assay methods, serologic status, disease stages, or types of treatment; (4) some patients with NMOSD do not have AQP4-Ab; and (5) test results for the AQP4-Ab may not be readily available for the acute management of patients. Despite some similarity in their phenotypes, these NMOSD and NMOSD-mimics are distinct from each other in their pathogenesis, prognosis, and most importantly treatment. Understanding the detailed clinical, serological, radiological, and prognostic differences of these diseases will improve the proper management as well as diagnosis of patients.

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.

Elevated cerebrospinal fluid uric acid during relapse of neuromyelitis optica spectrum disorders

INTRODUCTION

Previous studies have shown that serum uric acid (UA) modulates outcomes of neurological diseases, although little is known about cerebrospinal fluid (CSF) UA levels in neuromyelitis optica spectrum disorders (NMOSDs).

METHODS

Cerebrospinal fluid and serum UA levels were measured in samples from 68 patients, including NMOSDs during relapse (n = 38) and controls with noninflammatory and non-neurodegenerative diseases (CTLs, n = 30). Correlation analysis was performed between CSF UA and clinical characteristics, serum UA, and blood-brain barrier integrity in NMOSDs.

RESULTS

Cerebrospinal fluid UA levels in NMOSDs were significantly higher than in CTLs (p = .002), while serum UA differences between NMOSDs and CTLs were not statistically significant. In NMOSDs, CSF UA levels were significantly higher in patients with an impaired blood-brain barrier than in patients with an intact one (p < .001), and significantly higher in longer disease duration than in shorter disease duration patients (p = .002). CSF UA levels were also significantly higher in active patients upon MRI than in inactive patients (p < .001), and significantly higher in patients with brain lesions than without brain lesions (p = .024). CSF UA was significantly associated with the serum UA levels (r = .454, p = .002), disease duration (r = .383, p = .018), and blood-brain barrier index (r = .805, p < .001), but did not correlate with age, gender, annualized relapse rate, duration, or severity of NMOSD. Multiple regression analysis demonstrated that CSF UA was independent of the blood-brain barrier index (β = .765, p < .001) and serum UA levels (β = .01, p = .019) in NMOSDs.

CONCLUSIONS

Cerebrospinal fluid UA levels were elevated in NMOSD patients during relapse, and were likely modified by serum UA levels and blood-brain barrier integrity.

Low serum vitamin D levels and anti-N-methyl-d-aspartate receptor encephalitis: A case-control study

BACKGROUND

Low vitamin D levels are associated with autoimmunity, but the relationship with anti-N-Methyl-d-aspartate receptor (anti-NMDAR) encephalitis is unknown.

METHODS

25(OH) D levels and clinical and cerebrospinal fluid parameters were evaluated in 30 patients with anti-NMDAR encephalitis and compared with 90 age-, sex-, and season-matched healthy controls.

RESULTS

25(OH)D levels were lower in patients with anti-NMDAR encephalitis compared to controls (43.89 ± 17.91 vs 64.24 ± 24.38 nmol/L, p < 0.001), especially for females (vs males, p = 0.008), aged ≤30 years (vs > 30 years, p = 0.002), severe impairment (mRS ≥ 5) (vs mRS < 5, p = 0.018), and limited treatment responses (vs favorable treatment, p = 0.02). Serum 25(OH)D levels were associated with age (r = 0.393, p = 0.032), and mRS (r = -0.417, p = 0.022).

CONCLUSIONS

Our data showed that serum 25(OH)D levels were reduced in patients with anti-NMDAR encephalitis.

Atypical presentations of acute disseminated encephalomyelitis (ADEM) in HIV infection

Acute disseminated encephalomyelitis is a monophasic demyelinating disorder of the central nervous system associated with various viral infections including HIV infection. We present the findings of seven HIV-infected patients with mild to moderate immunosuppression presenting with atypical features. Four patients had a multiphasic course; three patients had tumefactive lesions, and two patients had corpus callosum lesions. Two patients with the multiphasic course also had tumefactive lesions. Their clinical and radiological findings are presented. Despite the few cases, we propose that the dysimmune process lying between marked immunosuppression (CD4 < 200 cells/μL) and normal CD4 counts (CD4 > 500 cells/μL) might be responsible for these atypical presentations.

Visual impairment

This chapter can guide the use of imaging in the evaluation of common visual syndromes: transient visual disturbance, including migraine and amaurosis fugax; acute optic neuropathy complicating multiple sclerosis, neuromyelitis optica spectrum disorder, Leber hereditary optic neuropathy, and Susac syndrome; papilledema and pseudotumor cerebri syndrome; cerebral disturbances of vision, including posterior cerebral arterial occlusion, posterior reversible encephalopathy, hemianopia after anterior temporal lobe resection, posterior cortical atrophy, and conversion blindness. Finally, practical efforts in visual rehabilitation by sensory substitution for blind patients can improve their lives and disclose new information about the brain.

Structural MRI substrates of cognitive impairment in neuromyelitis optica

OBJECTIVE

To identify the clinical and structural MRI markers for predicting cognitive impairment (CI) in patients with neuromyelitis optica (NMO).

METHODS

Fifty-four patients with NMO and 27 healthy controls underwent extensive neuropsychological testing and multimodal 3.0T MRI. The patient group was classified as CI or cognitively preserved (CP), using a criterion of ≤1.5 SD on at least 2 cognitive domains. MRI measurements included white matter (WM) lesion volume, gray matter (GM), WM, and deep GM (DGM) volume, cortical thickness, and the severity and extent of WM tract diffusion metric alterations based on fractional anisotropy and mean, axial, and radial diffusivity. Groups were compared using a multivariate general linear model, and clinical and MRI measurements were related to average cognition z scores by partial correlations and a stepwise linear regression model.

RESULTS

Twenty-six patients with NMO (48.2%) were classified as CI and showed WM tract diffusion abnormalities, particularly increased radial diffusivity, and GM especially DGM atrophy compared with healthy controls. Patients classified as CP also showed alterations of WM tract diffusion but without significant GM atrophy. Compared with the CP group, patients with CI demonstrated a lower level of education and decreased hippocampal volume. In the whole patient group, average cognition z scores were best predicted by the level of education and hippocampal volume (R(2) = 0.46, p < 0.001).

CONCLUSION

In patients with NMO, WM tract integrity disruption was identified in both CP and CI groups. GM atrophy, particularly in the DGM, was only found in the CI group. Hippocampal volume is the main MRI predictor of cognition in 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.

Iron metabolism in neuromyelitis optica patients

OBJECTIVE

The aim of this study was to investigate whether there was any relationship between iron metabolism and clinical features of NMO patients.

METHODS

We measured serum iron, ferritin, and transferrin levels in 25 patients with NMO and 25 controls.

RESULTS

The patients with NMO had significantly decreased serum iron and increased serum ferritin (P=0.001 and 0.002, respectively), both of which were in normal ranges. The serum iron level of NMO patients was not correlated with disease duration, relapse number, or magnetic resonance imaging lesions. After multivariate linear regression analysis, the serum iron level was correlated with age (P=0.003) but not EDSS score.

CONCLUSIONS

The iron metabolism might reflect the chronic oxidative injury in NMO patients. It is still unclear whether iron metabolism is implicated in the pathogenesis of NMO.

A rare case of hyponatremia from a hypothalamic lesion in a patient with multiple sclerosis

The syndrome of inappropriate antidiuretic hormone secretion (SIADH) can occur from a variety of neurologic and systemic processes; however, it has rarely been seen in multiple sclerosis (MS). We report a case of SIADH in a patient with MS and compare it with previously reported English-only cases. A 32-year-old woman experienced generalized fatigue followed by confusion and was found to have profound hyponatremia. Her work-up demonstrated SIADH secondary to a discrete enhancing hypothalamic lesion. Despite the seldom occurrence of SIADH in MS, hypothalamic lesions are more common than appreciated and should be considered in patients presenting with hyponatremia or endocrinopathy symptoms.

Neuromyelitis optica: clinical features, immunopathogenesis and treatment

The term 'neuromyelitis optica' ('Devic's syndrome', NMO) refers to a syndrome characterized by optic neuritis and myelitis. In recent years, the condition has raised enormous interest among scientists and clinical neurologists, fuelled by the detection of a specific serum immunoglobulin (Ig)G reactivity (NMO-IgG) in up to 80% of patients with NMO. These autoantibodies were later shown to target aquaporin-4 (AQP4), the most abundant water channel in the central nervous system (CNS). Here we give an up-to-date overview of the clinical and paraclinical features, immunopathogenesis and treatment of NMO. We discuss the widening clinical spectrum of AQP4-related autoimmunity, the role of magnetic resonance imaging (MRI) and new diagnostic means such as optical coherence tomography in the diagnosis of NMO, the role of NMO-IgG, T cells and granulocytes in the pathophysiology of NMO, and outline prospects for new and emerging therapies for this rare, but often devastating condition.