Enhancing Brain Lesions during Acute Optic Neuritis and/or Longitudinally Extensive Transverse Myelitis May Portend a Higher Relapse Rate in Neuromyelitis Optica Spectrum Disorders

Combined platelet-to-lymphocyte ratio and blood-brain barrier biomarkers as indicators of disability in acute neuromyelitis optica spectrum disorder

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a complex neuroinflammatory disease characterized by severe disability. In this study, we investigated the relationship between cerebrospinal fluid (CSF)/serum albumin quotient (Qalb) and platelet to lymphocyte ratio (PLR) in assessing disease severity.

METHOD

A retrospective analysis of 72 NMOSD patients and 72 healthy controls was conducted, and patients were divided into two groups based on their Expanded Disability Status Scale (EDSS) scores.

RESULTS

NMOSD patients had significantly higher levels of serum PLR, neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and C-reactive protein (CRP) compared to healthy controls (all P<0.01). Patients in the EDSS≥4 group exhibited significantly elevated levels of Qalb, QIgG, QIgA, QIgM, and PLR (P=0.000, P<0.0001, P=0.0019, P=0.0001, respectively). Spearman's correlation test revealed significant positive associations between Qalb, QIgG, QIgA, QIgM, PLR, and EDSS score. Specifically, Qalb (r=0.571; P<0.001), QIgG (r=0.551; P<0.001), QIgA (r=0.519; P<0.001), and QIgM (r=0.541; P<0.001) demonstrated significant positive correlations with EDSS score, while PLR exhibited a moderate positive correlation (r=0.545; P<0.001) with EDSS score and a mild positive association (r=0.387; P<0.001) with Qalb. The increase of Qalb was positively correlated with the increased EDSS score (r=0.528, P=0.001), as well as the increase of QIgG (r=0.509, P=0.001), and the increase of QIgA (r=0.4989, P=0.03). ROC analysis indicated that Qalb, QIgG, QIgA, QIgM, and PLR levels could effectively serve as indicators of NMOSD severity (all P<0.0001). Multivariate analysis confirmed the independent significance of Qalb and PLR in assessing disease severity (P=0.000).

CONCLUSION

These findings provide valuable insights into the risk and pathogenesis of NMOSD and highlight the potential of Qalb and PLR as independent markers for disease severity assessment in NMOSD patients.

Neuromyelitis Optica Spectrum Disorders

PURPOSE OF REVIEW

This article reviews the cardinal clinical features, distinct immunopathology, current diagnostic criteria, relapse-related risk factors, emerging biomarkers, and evolving treatment strategies pertaining to neuromyelitis optica spectrum disorders (NMOSD).

RECENT FINDINGS

The discovery of the pathogenic aquaporin-4 (AQP4)-IgG autoantibody and characterization of NMOSD as an autoimmune astrocytopathy have spearheaded the identification of key immunologic therapeutic targets in this disease, including but not limited to the complement system, the interleukin 6 (IL-6) receptor, and B cells. Accordingly, four recent randomized controlled trials have demonstrated the efficacy of three new NMOSD therapies, namely eculizumab, satralizumab, and inebilizumab.

SUMMARY

Currently, NMOSD poses both diagnostic and treatment challenges. It is debated whether individuals who are seropositive for myelin oligodendrocyte glycoprotein (MOG)-IgG belong within the neuromyelitis optica spectrum. This discussion is fueled by disparities in treatment responses between patients who are AQP4-IgG seropositive and seronegative, suggesting different immunopathologic mechanisms may govern these conditions. As our understanding regarding the immune pathophysiology of NMOSD expands, emerging biomarkers, including serum neurofilament light chain and glial fibrillary acidic protein (GFAP), may facilitate earlier relapse detection and inform long-term treatment decisions. Future research focal points should include strategies to optimize relapse management, restorative treatments that augment neurologic recovery, and practical solutions that promote equitable access to approved therapies for all patients with NMOSD.

Differential patterns of interhemispheric functional connectivity between AQP4-optic neuritis and MOG-optic neuritis: a resting-state functional MRI study

BACKGROUND

Several neuroimaging studies demonstrated that optic neuritis (ON) leads to functional and anatomical architecture changes in the brain. The alterations of interhemispheric functional connectivity (IFC) in patients with AQP4-ON and myelin oligodendrocyte glycoprotein (MOG)-ON are not well understood.

PURPOSE

To investigate the differential patterns of VMHC in patients with AQP4-ON and MOG-ON.

MATERIAL AND METHODS

Twenty-one patients with AQP4-ON, 11 patients with MOG-ON, and 34 healthy controls underwent resting-state MRI scans. One-way ANOVA was used to identify regions in which the zVMHC differed among the three groups. Post hoc two-sample t-tests were then conducted to compare zVMHC values between pairs of groups. Pearson correlation analysis was conducted to reveal relationships between mean zVMHC values and clinical variables in the AQP4-ON and MOG-ON groups.

RESULTS

The results revealed significant differences in zVMHC values in the PreCG among the three groups. Compared to the control group: the AQP4-ON group showed significantly lower VMHC values in the superior temporal gyrus, inferior frontal gyrus, and PreCG; and the MOG-ON group showed significantly higher zVMHC values in the PostCG. Compared to the AQP4-ON group, the MOG-ON group showed significantly lower zVMHC values in the PreCG/PostCG (voxel-level P<0.01, GRF correction, cluster-level P<0.05).

CONCLUSION

Patients with AQP4-ON and those with MOG-ON showed abnormal VMHC in the motor cortices, sensorimotor cortices, and frontal lobe, possibly indicating impaired sensorimotor function in patients with ON. Moreover, differential patterns of VMHC in patients with AQP4-ON, compared to patients with MOG-ON, might serve as a clinical indicator for classification of ON.

Risk of relapse in patients with neuromyelitis optica spectrum disorder: Recognition and preventive strategy

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune inflammatory disorder of the central nervous system (CNS) that is mainly associated with serum autoantibodies against aquaporin-4 (AQP4) in astrocytes. The relapsing clinical course of NMOSD, which can be blinding and disabling due to severe visual impairment, spinal cord lesions and a group of brain syndromes, suggests the importance of accurately evaluating the likelihood and severity of relapse at an early stage of the disease. To date, many risk factors have been revealed in association with relapse, and only some of them are supported by substantial evidence. Furthermore, while the clinical use of conventional immunosuppressants is mostly empirical, an increasing number of emerging therapies for monoclonal antibodies have been confirmed by several randomized placebo-controlled trials to be effective and safe for relapse prevention. In this review, we summarize the reported risk factors that may influence the frequency, symptoms, severity and prognosis of relapse in NMOSD, as well as the efficacy and safety of emerging therapies for relapse prevention. All of these results enable us to better recognize patients who are at higher risk of relapse and suggest more effective monoclonal antibody therapies for use in these patients.

Brain MRI Findings in Pediatric-Onset Neuromyelitis Optica Spectrum Disorder: Challenges in Differentiation from Acute Disseminated Encephalomyelitis

BACKGROUND AND PURPOSE

Differentiating pediatric-onset neuromyelitis optica spectrum disorder from acute disseminated encephalomyelitis could be challenging, especially in cases presenting with only brain manifestations. Our purpose was to investigate brain MR imaging features that may help distinguish these 2 entities.

MATERIALS AND METHODS

We retrospectively examined initial brain MR imaging studies of 10 patients with pediatric-onset neuromyelitis optica spectrum disorder (female/male ratio, 7:3) and 10 patients with acute disseminated encephalomyelitis (female/male ratio, 2:8). The mean age of the patients was 10.3 ± 5.6 and 8.7 ± 5.3 years, respectively. Brain lesions were evaluated with respect to location, extent, expansion, T1 hypointensity, contrast enhancement/pattern, and diffusion characteristics. The χ² test (Yates or Fisher exact χ²tests) was used to compare differences between groups.

RESULTS

Cerebral subcortical ± juxtacortical and pons ± middle cerebellar peduncle were the most frequent locations involved in both neuromyelitis optica spectrum disorder (n = 5 and 4, respectively) and acute disseminated encephalomyelitis (n = 9 and 7, respectively). Thalamic lesions were more frequent in acute disseminated encephalomyelitis (P = .020) and were detected only in 1 patient with neuromyelitis optica spectrum disorder. None of the patients with neuromyelitis optica spectrum disorder had hypothalamic, internal capsule, or cortical lesions. The internal capsule involvement was found to be significantly different between groups (P = .033). There was no significant difference in terms of extent, expansion, T1 hypointensity, contrast enhancement/pattern, and diffusion characteristics.

CONCLUSIONS

Although there is a considerable overlap in brain MR imaging findings, thalamic and internal capsule involvement could be used to differentiate pediatric-onset neuromyelitis optica spectrum disorder from acute disseminated encephalomyelitis.

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.