Clinical and radiological profile of neuromyelitis optica spectrum disorders in an Ecuadorian cohort

Discrepancy in clinical and laboratory profiles of NMOSD patients between AQP4 antibody positive and negative: can NMOSD be diagnosed without AQP4 antibody?

AQP4-IgG has been considered as the pathogenic factor leading to NMOSD. However, about 20-30% of patients lack AQP4-IgG. So far, all therapeutic medicines are ineffective for NMOSD patients without AQP4 IgG. Thus AQP4-IgG is the pathogenic factor of NMOSD has been suspected and challenged. In addition, lack of efficacy of immunotherapy in NMOSD without AQP4 IgG has been a serious problem in the neurology. Identifying the clinical and laboratory characteristics and diversities between NMOSD patients with and without AQP4-IgG can be helpful to further explore the pathogenesis of NMOSD and guide clinical treatment. This is a single-centre retrospective study in The First Hospital of Jilin University, China including 92 patients diagnosed as NMOSD from January 2013 to January 2015. The characteristics of clinic, blood, cerebrospinal fluid (CSF), and image between AQP4-IgG negative (AQP4-IgG-) and AQP4-IgG positive (AQP4-IgG+) NMOSDs were compared. Our results showed that in the AQP4-IgG+ group, the ratio of women to men was 5.55, while in AQP4-IgG- group was 1.54 (P = 0.0092). In the AQP4-IgG+ patients, the expanded disability status scale (EDSS) was from 0 to 8.5, with an average of 5.550 ± 0.25, and the AQP4-IgG- patients had the EDSS score from 0 to 9, with an average of 4.032 ± 0.36 (P = 0.0006), which mainly affected movement system (P < 0.05) and superficial sensory impairment (P < 0.05). In the AQP4-IgG+ group, the blood brain barrier (BBB) permeability (P = 0.0210) and myelin basic protein (MBP) were increased (P = 0.0310) when compared to AQP4-IgG- group. Higher level IL-17 was seen in AQP4-IgG+ group than AQP4-IgG- group (P= 0.0066). Our results demonstrated that the NMOSD with AQP4-IgG more likely occurred in women and presented more severe clinical symptoms as well as significant BBB damage and increased MBP and IL-17 in CSF and blood, respectively compared with NMOSD without AQP4-IgG group. The differences in clinical and laboratory profiles between NMOSD with and without AQP4-IgG indicate the heterogeneity of NMOSD, in which AQP4-IgG may not be the only pathogenic molecule. It is necessary to find more pathogenic factors and to explore the new pathogenesis of NMOSD and therapeutic methods in the future.

Area postrema syndrome in neuromyelitis optica spectrum disorder: diagnostic challenges and descriptive patterns

Background

Although area postrema syndrome (APS) is one of the core clinical features of neuromyelitis optic spectrum disorder (NMOSD), it is frequently misdiagnosed as gastrointestinal or systemic disorders. In this study, we describe the diagnostic challenges in NMOSD patients with APS and their characteristic clinical and radiological features. All patients who attended our university hospitals during the period from March 2019 to August 2020 with a diagnosis of NMOSD according to the latest diagnostic criteria were admitted and evaluated clinically, radiologically with gadolinium-enhanced brain and spinal MRI, measures of serum Anti-Aquaporin 4 (Anti-AQP4) and clinical status using the Expanded Disability Status Scale (EDSS) scores. APS was diagnosed if there was a history of intractable nausea, vomiting, or hiccups (INVH) that had lasted longer than 1 week with the exclusion of other etiologies, or less than 48 h if associated with a lesion in the dorsal medulla on MRI scan.

Results

Twenty out of 90 (22.2%) identified patients with a diagnosis of NMOSD had a history of unexplained intractable nausea, vomiting or hiccoughs lasting an average of 20 days. Seventeen patients were anti-Aquaporin 4 seropositive. Seven patients (35%) presented initially with isolated clinical features of APS and were diagnosed only after subsequent relapse. Patients with APS preceding other core clinical presentations (13 cases, 65%) were diagnosed after development of motor manifestations. All patients developed acute myelitis during the course of illness. Brain and spinal MRI scans showed that 13 had a linear lesion in the dorsal tegmentum of the medulla oblongata adjacent to the fourth ventricle. Otherwise, longitudinally extensive transverse myelitis was found in 80%, while 35% showed extension of the cord lesion to the AP.

Conclusions

APS as a core clinical characteristic of NMOSD is not a rare presentation as was previously thought and can occur in both AQP4-seropositive and seronegative NMOSD.

Comparisons of clinical phenotype, radiological and laboratory features, and therapy of neuromyelitis optica spectrum disorder by regions: update and challenges

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory demyelinating disease of the central nervous system (CNS) associated with autoantibody (ab) to aquaporin-4 (AQP4). There is obvious variation between regions and countries in the epidemiology, clinical features and management in NMOSD. Based on published population-based observation and cohort studies, the different clinical pattern of NMOSD has been seen in several geographical regions and some of these patients with NMOSD-like features do not fully meet the current diagnostic criteria, which is needed to consider the value of recently revised diagnostic criteria. At present, all treatments applied in NMOSD have made great progress, however, these treatments failed in AQP4 ab negative and refractory patients. Therefore, it is necessary to turn into an innovative idea and to open a new era of NMOSD treatment to develop novel and diverse targets and effective therapeutic drugs in NMOSD and to conduct the trails in large clinical samples and case-control studies to confirm their therapeutic effects on NMOSD in the future, which still remain a challenge.