Pediatric Neuromyelitis Optica Spectrum Disorder: Case Series and Literature Review

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a central nervous system (CNS) inflammatory demyelinating disease characterized by recurrent inflammatory events that primarily involve optic nerves and the spinal cord, but also affect other regions of the CNS, including hypothalamus, area postrema and periaqueductal gray matter. The aquaporin-4 antibody (AQP4-IgG) is specific for NMOSD. Recently, myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) have been found in a group of AQP4-IgG negative patients. NMOSD is rare among children and adolescents, but early diagnosis is important to start adequate therapy. In this report, we present cases of seven pediatric patients with NMOSD and we review the clinical and neuroimaging characteristics, diagnosis, and treatment of NMOSD in children.

Brighter spotty lesions on spinal MRI help differentiate AQP4 antibody-positive NMOSD from MOGAD

In a large acute myelitis cohort, we aimed to determine whether brighter spotty lesions (BSLs)—using the refined terminology—on spinal magnetic resonance imaging (MRI) help distinguish aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) from myelin oligodendrocyte glycoprotein antibody disease (MOGAD). An experienced neuro-radiologist and two neurologists independently analyzed 133 spinal MRI scans (65 from MOGAD and 68 from AQP4-NMOSD) acquired within 1 month of attacks. BSLs were observed in 18 of 61 (30%) participants with AQP4-NMOSD, while none of 49 participants with MOGAD showed BSL ( p < 0.001). BSL during the acute phase would be useful to differentiate AQP4-NMOSD from MOGAD.

Relapse activity in the chronic phase of anti-myelin-oligodendrocyte glycoprotein antibody-associated disease

Objective The patterns of relapse and relapse-prevention strategies for anti-myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are not completely investigated. We compared the patterns of relapse in later stages of MOGAD with those of anti-aquaporin-4 antibody (AQP4-Ab)-positive neuromyelitis optica spectrum disorder (NMOSD). Methods In this observational, comparative cohort study, 66 patients with MOGAD and 90 with AQP4-Ab-positive NMOSD were enrolled. We compared the patterns of relapse and annualized relapse rates (ARRs) in the first 10 years from disease onset, stratified by relapse-prevention treatments. Results Approximately 50% of the patients with MOGAD experienced relapses in the first 10 years. Among those not undergoing relapse-prevention treatments, ARRs in the first 5 years were slightly lower in MOGAD patients than in AQP4-Ab-positive NMOSD patients (MOGAD vs. AQP4-Ab NMOSD: 0.19 vs. 0.30; p = 0.0753). After 5 years, the ARR decreased in MOGAD patients (MOGAD vs. AQP4-Ab NMOSD: 0.05 vs. 0.34; p = 0.0001), with a 72% reduction from the first 5 years (p = 0.0090). Eight (61.5%) of the 13 MOGAD patients with more than 10-year follow-up from disease onset showed relapse 10 years after onset. Clustering in the timing and phenotype of attacks was observed in both disease patients. The effectiveness of long-term low-dose oral PSL for relapse prevention in patients with MOGAD has not been determined. Conclusions The relapse risk in patients with MOGAD is generally lower than that in patients with AQP4-Ab-positive NMOSD, especially 5 years after onset. Meanwhile, relapses later than 10 years from onset are not rare in both diseases.

The difference of the retinal structural and microvascular characteristics in patients with MOGAD-ON and AQP4-ON

Background Antibodies against myelin-oligodendrocyte-glycoprotein (MOG-Abs) associated disorders (MOGAD) have been recognized as a disease entity in their own right. Optic neuritis (ON) is the most common symptom in MOGAD. Objective To demonstrate the differences in retinal microvascular characteristics between patients with MOGAD-ON and aquaporin-4 antibody (AQP4-Ab) positive ON. Methods A prospective study in which optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) were used to measure retinal and microvascular parameters. Results 22 MOGAD-ON eyes, 32 AQP4-ON eyes and 60 control eyes were included in the study. The thickness of RNFL and GCC in MOGAD-ON eyes is significantly lower than that of HC (p <0.001, respectively), but comparable to AQP4-ON eyes. The vessel density in retina capillary plexus (RCP) reduced significantly in MOGAD-ON than that in AQP4-ON (p < 0.05, respectively). Unlike AQP4-ON, the visual accuracy in MOGAD-ON was positivitly correlated with vessel density of superficial RCP (P = 0.010) and ON relaspe times (P = 0.038). Conclusion The retinal neuro-axonal damages between MOGAD-ON and AQP4-ON were comparable. Unlike AQP4-ON eyes, microvascular densities were significantly reduced in MOGAD-ON, and was positively correlated with the deterioration of visual acuity in MOGAD-ON.

An uncommon cause of vertigo: Neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an uncommon antibody-mediated disease of the central nervous system. Its classic presentation includes long segments of spinal cord inflammation, optic neuritis with or without intractable vomiting, and hiccups. Here, we described a case of a 39-year-old woman with an atypical presentation of vertigo, which was finally diagnosed as NMOSD by a positive serum aquaporin-4 antibody.

The use of OCT in good visual acuity MOGAD and AQP4-NMOSD patients; with and without optic neuritis

Myelin oligodendrocyte-antibody-associated disease (MOGAD) often presents with severe optic neuritis (ON) but tends to recover better than in aquaporin-4 antibody neuromyelitis optica spectrum disorder (AQP4-NMOSD). We measured OCT and VEP in MOGAD and AQP4-NMOSD eyes with good visual function, with or without previous ON episodes. Surprisingly, OCT and/or VEPs were abnormal in 84% MOGAD-ON versus 38% AQP4-NMOSD-ON eyes (p = 0.009) with good vision, compared with 18% and 17% respectively of eyes with no previous ON. A sub-group with macular OCT performed as part of a research study confirmed both retinal and macular defects in visually-recovered MOGAD eyes. These findings have implications for investigation and management of MOGAD patients.