Increased frequency and severity of restless legs syndrome in patients with 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.

Exploring resting-state EEG oscillations in patients with Neuromyelitis Optica Spectrum Disorder

BACKGROUND AND OBJECTIVE

Quantitative resting-state electroencephalography (rs-EEG) is a convenient method for characterizing the functional impairments and adaptations of the brain that has been shown to be valuable for assessing many neurological and psychiatric disorders, especially in monitoring disease status and assisting neuromodulation treatment. However, it has not yet been explored in patients with neuromyelitis optica spectrum disorder (NMOSD). This study aimed to investigate the rs-EEG features of NMOSD patients and explore the rs-EEG features related to disease characteristics and complications (such as anxiety, depression, and fatigue).

METHODS

A total of 32 NMOSD patients and 20 healthy controls (HCs) were recruited; their demographic and disease information were collected, and their anxiety, depression, and fatigue symptoms were evaluated. The rs-EEG power spectra of all the participants were obtained. After excluding the participants with low-quality rs-EEG data during processing, statistical analysis was conducted based on the clinical information and rs-EEG data of 29 patients and 19 HCs. The rs-EEG power (the mean spectral energy (MSE) of absolute power and relative power in all frequency bands, as well as the specific power for all electrode sites) of NMOSD patients and HCs was compared. Furthermore, correlation analyses were performed between rs-EEG power and other variables for NMOSD patients (including the disease characteristics and complications).

RESULTS

The distribution of the rs-EEG power spectra in NMOSD patients was similar to that in HCs. The dominant alpha-peaks shifted significantly towards a lower frequency for patients when compared to HCs. The delta and theta power was significantly increased in the NMOSD group compared to that in the HC group. The alpha oscillation power was found to be significantly negatively associated with the degree of anxiety (reflected by the anxiety subscore of hospital anxiety and depression scale (HADS)) and the degree of depression (reflected by the depression subscore of HADS). The gamma oscillation power was revealed to be significantly positively correlated with the fatigue severity scale (FSS) score, while further analysis indicated that the electrode sites of almost the whole brain region showing correlations with fatigue. Regarding the disease variables, no statistically significant rs-EEG features were related to the main disease features in NMOSD patients.

CONCLUSION

The results of this study suggest that the rs-EEG power spectra of NMOSD patients show increased slow oscillations and are potential biomarkers of widespread white matter microstructural damage in NMOSD. Moreover, this study revealed the rs-EEG features associated with anxiety, depression, and fatigue in NMOSD patients, which might help in the evaluation of these complications and the development of neuromodulation treatment. Quantitative rs-EEG analysis may play an important role in the management of NMOSD patients, and future studies are warranted to more comprehensively understand its application value.

Multiple Sclerosis and related disorders

Multiple Sclerosis (MS) is a common neuroinflammatory disorder which is associated with disabling clinical consequences. The MS disease process may involve neural centers implicated in the control of breathing, leading to ventilatory disturbances during both wakefulness and sleep. In this chapter, a brief overview of MS disease mechanisms and clinical sequelae including sleep disorders is provided. The chapter then focuses on obstructive sleep apnea-hypopnea (OSAH) which is the most prevalent respiratory control abnormality encountered in ambulatory MS patients. The diagnosis, prevalence, and clinical consequences as well as data on effects of OSAH treatment in MS patients are discussed, including the impact on the disabling symptom of fatigue and other clinical sequelae. We also review pathophysiologic mechanisms contributing to OSAH in MS, and in turn mechanisms by which OSAH may impact on the MS disease process, resulting in a bidirectional relationship between these two conditions. We then discuss central sleep apnea, other respiratory control disturbances, and the pathogenesis and management of respiratory muscle weakness and chronic hypoventilation in MS. We also provide a brief overview of Neuromyelitis Optica Spectrum Disorders and review current data on respiratory control disturbances and sleep-disordered breathing in that condition.

Symptomatic and restorative therapies in neuromyelitis optica spectrum disorders

Neuromyelitis optica spectrum disorders (NMOSD) are a group of autoimmune inflammatory conditions that primarily target the optic nerves, spinal cord, brainstem, and occasionally the cerebrum. NMOSD is characterized by recurrent attacks of visual, motor, and/or sensory dysfunction that often result in severe neurological deficits. In recent years, there has been a significant progress in relapse treatment and prevention but the residual disability per attack remains high. Although symptomatic and restorative research has been limited in NMOSD, some therapeutic approaches can be inferred from published case series and evidence from multiple sclerosis literature. In this review, we will discuss established and emerging therapeutic options for symptomatic treatment and restoration of function in NMOSD. We highlight NMOSD-specific considerations and identify potential areas for future research. The review covers pharmacologic, non-pharmacologic, and neuromodulatory approaches to neuropathic pain, tonic spasms, muscle tone abnormalities, sphincter dysfunction, motor and visual impairment, fatigue, sleep disorders, and neuropsychological symptoms. In addition, we briefly discuss remyelinating agents and mesenchymal stem cell transplantation in NMOSD.

Acute-onset Restless legs syndrome in acute neurological conditions-a prospective study on patients with the Guillain-Barre syndrome and acute stroke

OBJECTIVES

While the Restless legs syndrome (RLS) is usually recognized as a chronic condition, it has often been diagnosed among patients with acute neurological illnesses, in which limb discomfort is reported. This study was conducted to determine how many among these, actually have acute-onset RLS, and also to evaluate characteristics of this subgroup of patients with Guillain-Barre syndrome (GBS) and stroke developing acute-onset RLS.

METHODS

Consecutive patients diagnosed with GBS and eligible stroke patients, admitted to our Neurology services over a 1-year period, were enrolled. They were evaluated for symptoms of RLS based on IRLSSG consensus criteria and the AIIMS RLS Questionnaire for Indian patients (ARQIP).

RESULTS

Forty adults with GBS and 58 with stroke were included. A total of 10 of the 40 (25%) patients with GBS developed definite acute RLS, which was mostly monophasic. Seven (70%) of these had demyelinating type of GBS, a significant association with acute RLS (P = .024). Six of the 58 stroke patients (10%) developed definite acute-onset, often persistent RLS. Subcortical location showed significant association with increased risk of developing acute RLS (P < .001). All patients diagnosed with acute-onset RLS had an immediate and good response to dopamine agonists.

CONCLUSION

This is the first study showing that acute-onset RLS is common, affecting nearly 25% of patients with GBS and 10% patients with acute stroke. Recognizing and treating it can majorly contribute toward symptom relief and early improvement in the quality of life for this population.