Association of subcortical structural shapes with fatigue in neuromyelitis optica spectrum disorder

Usefulness of the MFIS-K, FSS, and FACIT-F Fatigue Scales in Korean Patients With MS, NMOSD, and MOGAD

BACKGROUND AND PURPOSE

Fatigue is common in demyelinating disorders of the central nervous system (CNS), including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). We aimed to validate the usefulness of the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) and the Fatigue Severity Scale (FSS) relative to the Korean version of the Modified Fatigue Impact Scale (MFIS-K) in Korean patients with MS, NMOSD, and MOGAD.

METHODS

There were 294 patients with MS (n=120), NMOSD (n=103), or MOGAD (n=71) enrolled in a prospective demyelinating CNS registry. Fatigue was measured using the FACIT-F, MFIS-K, and FSS. Sleep quality, quality of life, depression, and pain were evaluated using the Pittsburgh Sleep Quality Index (PSQI), 36-item Short-Form Survey (SF-36), and Beck Depression Inventory-II (BDI-II).

RESULTS

The MFIS-K, FACIT-F, and FSS scores showed high internal consistencies and strong correlations with each other in the MS, NMOSD, and MOGAD groups. The scores on all three fatigue scales were correlated with PSQI, SF-36, and BDI-II results in the three groups. The areas under the receiver operating characteristic curves for the FSS and FACIT-F were 0.834 and 0.835, respectively, for MS, 0.877 and 0.833 for NMOSD, and 0.925 and 0.883 for MOGAD.

CONCLUSIONS

These results suggest that the MFIS-K, FSS, and FACIT-F are useful and valuable assessment instruments for evaluating fatigue in Korean patients with MS, NMOSD, and MOGAD.

Temporal and topological properties of dynamic networks reflect disability in patients with neuromyelitis optica spectrum disorders

Approximately 36% of patients with neuromyelitis optica spectrum disorders (NMOSD) suffer from severe visual and motor disability (blindness or light perception or unable to walk) with abnormalities of whole-brain functional networks. However, it remains unclear how whole-brain functional networks and their dynamic properties are related to clinical disability in patients with NMOSD. Our study recruited 30 NMOSD patients (37.70 ± 11.99 years) and 45 healthy controls (HC, 41.84 ± 11.23 years). The independent component analysis, sliding-window approach and graph theory analysis were used to explore the static strength, time-varying and topological properties of large-scale functional networks and their associations with disability in NMOSD. Compared to HC, NMOSD patients showed significant alterations in dynamic networks rather than static networks. Specifically, NMOSD patients showed increased occurrence (fractional occupancy; P < 0.001) and more dwell times of the low-connectivity state (P < 0.001) with fewer transitions (P = 0.028) between states than HC, and higher fractional occupancy, increased dwell times of the low-connectivity state and lower transitions were related to more severe disability. Moreover, NMOSD patients exhibited altered small-worldness, decreased degree centrality and reduced clustering coefficients of hub nodes in dynamic networks, related to clinical disability. NMOSD patients exhibited higher occurrence and more dwell time in low-connectivity states, along with fewer transitions between states and decreased topological organizations, revealing the disrupted communication and coordination among brain networks over time. Our findings could provide new perspective to help us better understand the neuropathological mechanism of the clinical disability in NMOSD.

Correlation of GABA+ levels in the medial prefrontal cortex and circulating follicular helper T cells in neuromyelitis optica spectrum disorder patients with cognitive impairment

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) associated with cognitive impairment (CI) is acknowledged. However, the underlying pathogenesis and involvement of the immune system remain unclear.

OBJECTIVES

This study aimed to investigate the alterations in immune cells, cytokines, and GABA+ levels in NMOSD patients with cognitive deficits.

METHODS

Thirty-eight NMOSD patients and 38 healthy controls (HCs) were included. NMOSD patients were stratified as NMOSD-CI and NMOSD-CP groups. The difference in cognitive functions, Tfh and cytokines, and GABA+ levels were assessed, and their correlations were calculated.

RESULTS

NMOSD-CI patients showed worse performance on all cognitive tests, and the percentage of circulating follicular helper T cells (cTfh) was significantly elevated. The frequency of cTfh was positively and negatively correlated with Stroop-A and AVLT long-delayed scores, respectively. IL-21 was remarkably higher in NMOSD-CI and NMOSD-CP. The level of GABA+ in medial prefrontal cortex (mPFC) was significantly decreased in NMOSD-CI and was proved positively and negatively correlated with Symbol Digit Modalities Test and the frequency of circulating Tfh cells, respectively.

CONCLUSION

In NMOSD-CI patients, all cognitive domains were impacted, , while GABA+ levels in mPFC were decreased. GABA+ levels in NMOSD-CI were negatively correlated with the frequency of cTfh, suggesting the underlying coupling mechanism between immune responses and neurotransmitter metabolism in CI in NMOSD patients.

A comprehensive review of the advances in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare relapsing neuroinflammatory autoimmune astrocytopathy, with a predilection for the optic nerves and spinal cord. Most cases are characterised by aquaporin-4-antibody positivity and have a relapsing disease course, which is associated with accrual of disability. Although the prognosis in NMOSD has improved markedly over the past few years owing to advances in diagnosis and therapeutics, it remains a severe disease. In this article, we review the evolution of our understanding of NMOSD, its pathogenesis, clinical features, disease course, treatment options and associated symptoms. We also address the gaps in knowledge and areas for future research focus.

Differentiation between multiple sclerosis and neuromyelitis optica spectrum disorder using a deep learning model

Multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) are autoimmune inflammatory disorders of the central nervous system (CNS) with similar characteristics. The differential diagnosis between MS and NMOSD is critical for initiating early effective therapy. In this study, we developed a deep learning model to differentiate between multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) using brain magnetic resonance imaging (MRI) data. The model was based on a modified ResNet18 convolution neural network trained with 5-channel images created by selecting five 2D slices of 3D FLAIR images. The accuracy of the model was 76.1%, with a sensitivity of 77.3% and a specificity of 74.8%. Positive and negative predictive values were 76.9% and 78.6%, respectively, with an area under the curve of 0.85. Application of Grad-CAM to the model revealed that white matter lesions were the major classifier. This compact model may aid in the differential diagnosis of MS and NMOSD in clinical practice.

Brain structural and functional connectivity alterations are associated with fatigue in neuromyelitis optica spectrum disorder

Background

Many patients with neurological disorders experience chronic fatigue, but the neural mechanisms involved are unclear.

Objective

Here we investigated whether the brain structural and functional connectivity alterations were involved in fatigue related to neuromyelitis optica spectrum disorder (NMOSD).

Methods

This prospective pilot study used structural and resting-state functional brain magnetic resonance imaging to compare total cortical thickness, cortical surface area, deep gray matter volume and functional connectivity (FC) between 33 patients with NMOSD and 20 healthy controls (HCs). Patients were subgrouped as low fatigue (LF) and high fatigue (HF).

Results

HF patients scored higher on the Hamilton Anxiety Rating Scale and Hamilton Rating Scale for Depression than LF patients and HCs. The two patient subgroups and HC group did not differ significantly in cortical thickness, cortical surface area and volumes of the bilateral caudate nucleus, bilateral putamen, bilateral amygdala, bilateral hippocampus, bilateral thalamus proper or right nucleus accumbens (p > 0.05). However, after correcting for age, sex, years of education, anxiety and depression, HF patients showed larger left pallidum than HCs (0.1573 ± 0.0214 vs 0.1372 ± 0.0145, p = 0.009). Meanwhile, both LF patients (0.0377 ± 0.0052 vs 0.0417 ± 0.0052, p = 0.009) and HF patients (0.0361 ± 0.0071 vs 0.0417 ± 0.0052, p = 0.013) showed smaller left nucleus accumbens than HCs.. Compared with LF patients, HF patients showed significantly decreased FC between the left pallidum and bilateral cerebellar posterior lobes.

Conclusions

This was the first evidence linking structural and functional alterations in the brain to fatigue in NMOSD, and in the future, long term follow-up was necessary.