High false-positive rate of questionnaire-based restless legs syndrome diagnosis in multiple sclerosis

Sleepiness in neurological disorders

Sleepiness is a frequent and underrecognized symptom in neurological disorders, that impacts functional outcomes and quality of life. Multiple and potentially additive factors might contribute to sleepiness in neurological disorders, including sleep quality alterations, circadian rhythm disorders, drugs, and sleep disorders including sleep apnea or central disorders of hypersomnolence. Physician awareness of the possible symptoms of hypersomnolence, and associated causes is of crucial importance to allow proper identification and treatment of underlying causes. This review first provides a brief overview on clinical aspects of excessive daytime sleepiness, and diagnosis tools, then examines its frequency and mechanisms in various neurological disorders, including neurodegenerative disorders, multiple sclerosis, autoimmune encephalitis, epilepsy, and stroke.

Modification and Validation of a Diagnostic Questionnaire for Restless Legs Syndrome: Modified-Restless Legs Syndrome Diagnostic Questionnaire (m-RLS-DQ)

Background

Diagnostic questionnaire that are available for restless legs syndrome does not include items related to RLS mimics and, hence, increases chances of false positive cases. This study aimed at modification and validation of RLS-diagnostic Questionnaire.

Methods

During modification, additional items were identified, developed, and subjected to evaluation by experts. Experts were requested to validate the content of each item. Based on their responses, content validity indices (average and universal agreement) were calculated. It was then translated to Hindi and validated in a clinical population that included patients with RLS, somatic symptoms disorder, anxiety, other RLS mimics, and osteoarthritis. In addition, a group of healthy controls was also included. Face, concurrent, and discriminant validities were calculated.

Results

Among 209 subjects, nearly 40 subjects had clinical diagnosis of RLS, osteoarthritis, somatic-symptoms-disorder, and anxiety disorder, each. In addition, 16 patients had other RLS mimics (akathisia, varicose veins, BFS, leg-cramps, chronic insomnia) and 30 were healthy controls. After multiple revisions, content validity indices achieved a score of 1 for m-RLS-DQ. Sensitivity and specificity of m-RLS-DQ v. 1.4 for the diagnosis of RLS were 94.9% and 94.1%, respectively. For the diagnosis of RLS, PPV was 78.7%, and NPV was 98.7% with an accuracy of 94.3%. Less than one fourth of participants having chronic insomnia, somatic symptoms disorder, anxiety disorder, and knee osteoarthritis were found to be false positive on m-RLS-DQ; however, none of the healthy controls were found positive on m-RLS-DQ. Concurrent validity with clinical diagnosis of RLS was 0.83 (P < 0.001). Discriminant validity with somatic symptoms disorder was -0.14 (P = 0.03) and with osteoarthritis -0.24 (P < 0.001).

Conclusion

m-RLS-DQ is a valid instrument with acceptable psychometric properties, which can be used for the screening as well as diagnosis of RLS in clinical practice and research studies.

Sleep in multiple sclerosis: a systematic review and meta-analysis of polysomnographic findings

STUDY OBJECTIVES

This study aims to explore the polysomnographically measured sleep differences between patients with multiple sclerosis (MS) and healthy control patients.

METHODS

An electronic literature search was conducted in EMBASE, MEDLINE, all EBM databases, CINAHL, and PsycINFO from inception to March 2022. A random-effects model was applied to explore the pooled effect sizes of polysomnographic differences between patients with MS and control patients.

RESULTS

Thirteen studies were identified for meta-analysis. The meta-analyses revealed significant reductions in stage N2 sleep and sleep efficiency and increases in wake time after sleep onset, the periodic limb movement index, and the periodic limb movement arousal index in patients with MS compared with control patients. Meta-regression analyses showed that some of the heterogeneity was explained by age and daytime sleepiness of patients with MS.

CONCLUSIONS

Our study showed that polysomnographic abnormalities are present in MS. Our findings also underscore the need for a comprehensive polysomnographic assessment of sleep changes in patients with MS. Furthermore, the effects of age and daytime sleepiness in patients with MS on sleep changes should also be carefully considered and closely monitored in the management of MS.

CITATION

Zhang Y, Ren R, Yang L, et al. Sleep in multiple sclerosis: a systematic review and meta-analysis of polysomnographic findings. J Clin Sleep Med. 2023;19(2):253-265.

The prevalence of restless legs syndrome (RLS) in patients with multiple sclerosis (MS): a systematic review and meta-analysis-an update

INTRODUCTION

The prevalence of restless legs syndrome (RLS) is reported to vary in patients with multiple sclerosis (MS) in studies which are conducted in different populations. The goal of this systematic review and meta-analysis is to update the prevalence of RLS in MS cases.

METHODS

We searched PubMed, Scopus, EMBASE, CINAHL, Web of Science, Google Scholar, and gray literature including references from identified studies and conference abstracts which were published up to June 2021. Data on the total number of participants, first author, country, disease duration, number of controls, mean patient age, male and female numbers, mean EDSS, and number of cases and/or controls with RLS were extracted from the included studies.

RESULTS

The literature search revealed 855 articles; after deleting duplicates, 530 remained. For the meta-analysis, 75 studies were included (Fig. 1). In six articles, the authors did not differentiate between CIS and MS cases when reporting RLS cases. In total, 15,411 MS/CIS patients were evaluated and 4309 had RLS. The pooled prevalence of RLS was 28% (95% CI: 24-33%). The pooled prevalence of RLS in men was 22% (95% CI: 17-26%), and the pooled prevalence of RLS in women was 30% (95% CI: 25-35%). The pooled prevalence of RLS in controls was 8% (95% CI: 6-10%).

CONCLUSION

The results of this systematic review and meta-analysis show that the pooled prevalence of RLS is 28% in MS cases and 8%. The pooled prevalence is higher in women than men (30% vs 22%).

Relationship between presence of spinal cord lesion and restless legs syndrome in multiple sclerosis

BACKGROUND

Even though the prevalence of restless leg syndrome in multiple sclerosis (MS) is known to vary between 12.5% and 60%, the underlying pathophysiological mechanism remains unclear.

AIM

This study aims to investigate the relationship between spinal cord lesions and restless leg syndrome in MS.

MATERIALS AND METHODS

In total, 959 persons with MS were enrolled in this study. Demographic and clinical data of persons with MS were recorded by interviewing and medical records. Neurologists blind to the presence of restless leg syndrome evaluated MRI scans for the presence of demyelinating lesions in the brainstem and spinal cord.

RESULTS

The restless leg syndrome was detected in 222 participants (23.15%). Restless leg syndrome was not significantly linked to mean age, body mass index, gender, and MS duration, but persons with MS with restless leg syndrome have a higher disability level (p = 0.044). In addition, no difference in the brainstem and thoracic cord was found between persons with MS with and without restless leg syndrome, while there is a significant relationship between the presence of cervical cord lesion and restless leg syndrome.

CONCLUSION

Higher disability scores and characteristics of lesion patterns in the spinal cord could explain higher rates of restless leg syndrome in persons with MS. Considering the negative effects of restless leg syndrome, the increased awareness and treatment of restless leg syndrome among persons with MS is essential for better managing.

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.

Restless legs syndrome and related factors in people with multiple sclerosis in Turkey

OBJECTIVE

Restless legs syndrome is one of the most reported sleep disorders in multiple sclerosis (MS). The study aims to investigate the possible factors related to the occurrence and severity of restless legs syndrome in persons with MS (pwMS) comparing with healthy controls.

METHODS

This is a case-control study that included 447 pwMS and 57 healthy controls. Demographic and clinical data such as gender, age, duration of education, body mass index, marital status, disease duration, and MS type were recorded. Neurological disability was assessed by the Expanded Disability Status Scale. The Restless Legs Syndrome Rating Scale was used to assess the severity of restless legs syndrome.

RESULTS

The prevalence of restless legs syndrome in pwMS was 133 (29.8%) and 3 (4.9%) in healthy controls (p < 0.001). There was no significant difference between the groups in terms of gender, body mass index, and MS type (p > 0.05). Patients with restless legs syndrome have more advanced age, longer disease duration, and higher Expanded Disability Status Scale scores than patients without restless legs syndrome (p < 0.05). The correlation between restless legs syndrome severity and age, Expanded Disability Status Scale score, disease duration was not statistically significant (p > 0.05).

CONCLUSIONS

This study has shown that the presence of restless legs syndrome is high in persons with MS compared to healthy controls. Advanced age, disease duration, and higher disability level could be related to the increased rate of restless legs syndrome in persons with MS, especially those with high-frequency symptoms.

Restless legs syndrome in people with multiple sclerosis: An updated systematic review and meta-analyses

BACKGROUND

Restless legs syndrome (RLS) is a sensory-motor disorder characterized by an uncomfortable sensation felt in the lower extremity. The aim of this systematic review and meta-analyses was (i) to provide updated information on the prevalence and clinical characteristics of RLS amongst people with multiple sclerosis (PwMS) and (ii) clarify RLS-related factors in PwMS.

METHODS

MEDLINE (PubMed), Scopus, and EMBASE were searched from their inception through April 2021 for the following keywords: 'restless legs syndrome' or 'RLS' and 'multiple sclerosis' or 'MS'. For the analysis of RLS prevalence, we calculated the percentage of RLS sufferers amongst the PwMS and people without MS. The prevalence of RLS was pooled separately for PwMS and healthy controls, regardless of the heterogeneity between studies. The odds ratios (ORs) and 95% CIs were extracted from the data in order to analyze the association between MS and RLS.

RESULTS

Nineteen studies were included in the review (9 case-controlled and 10 cross-sectional).The mean prevalence of RLS in the MS population was 27.5%, ranging from 13.2% to 65.1%, higher than the healthy controls. Based on the case control studies, the pooled RLS prevalence was much higher in PwMS than in healthy controls (OR 4.535, 95% CI 3.043-6.759, p<0.001). The majority of studies found no significant relationship between the presence of RLS in PwMS with disability, disease duration, type of MS, age, or gender.

CONCLUSIONS

Our updated systematic review strengthens the evidence of the increased risk of RLS amongst PwMS. Nevertheless, significant data reporting on characteristics of the MS disease, which increases the risk of suffering from RLS, is still lacking.

Validity and reliability of the suggested immobilization test for measurement of restless legs syndrome severity in adults with multiple sclerosis

OBJECTIVE/BACKGROUND

Adults with multiple sclerosis (MS) often present with conditions that mimic restless legs syndrome (RLS), thereby adding complexity into the assessment of RLS severity. The current gold-standard measures of RLS severity rely on a fixed seven-day time frame, which limits the ability of these measures for studying acute changes in RLS severity. The present study examined if subjective and objective scores from the suggested immobilization test (SIT) provide a valid and reliable acute measure of RLS severity in persons with MS.

PATIENTS/METHODS

Participants with MS and RLS (n = 20) and MS without RLS (n = 20) were matched by age, gender, and disability. All participants completed validated questionnaires for RLS severity followed by the SIT, conducted at 18:00 (±15 min) on the same day of the week for two consecutive weeks. Participants wore accelerometer devices for seven nights to capture periodic limb movements (PLMs) during the night.

RESULTS

Self-reported RLS severity during the SIT had excellent construct validity and convergent validity, but moderate test-retest reliability. Device-measured PLMs, while not themselves a direct measure of RLS severity, were significantly associated with PLMs during the night and had excellent test-retest reliability during the SIT in adults with MS.

CONCLUSIONS

Our results suggest that the SIT represents a valid acute measure for capturing self-reported sensory aspects of RLS severity and should be considered in future research and clinical practice as a standardized acute measure of subjective RLS severity in adults with MS who present with RLS.

Association of Central Hypersomnia and Fatigue in Patients With Multiple Sclerosis: A Polysomnographic Study

OBJECTIVE

To evaluate sleepiness and central hypersomnia in multiple sclerosis (MS)-associated fatigue, we performed long-term polysomnography in patients with MS and healthy controls.

METHODS

Patients with MS and healthy controls completed questionnaires on sleep, fatigue, sleepiness, and depression. They underwent nocturnal polysomnography, multiple sleep latency tests, and bed rest 24-hour polysomnography. Patients were divided into 3 groups (fatigue and sleepiness, fatigue and no sleepiness, neither fatigue nor sleepiness).

RESULTS

Among 44 patients with MS, 19 (43.2%) had fatigue and sleepiness, 15 (34%) had only fatigue, and 10 (22.7%) had neither fatigue nor sleepiness. Compared to 24 controls, patients with fatigue and sleepiness had higher REM sleep percentages (median [interquartile range] 20.5% [19.6-24.7] vs 18.1% [12.6-20.6]), lower arousal indexes (12.7 [7.5-17.0] vs 22.4 [14.3-34.4]), and shorter daytime mean sleep latencies (8.6 [6.3-14.3] vs 16.6 [12.6-19.5] min). Restless leg syndrome, periodic leg movements, and sleep apnea had similar frequencies between groups. Central hypersomnia was found in 10 (53%) patients with fatigue and sleepiness (narcolepsy type 2, n = 2), in 2 (13%) patients with fatigue only, and in 3 (30%) patients with neither fatigue nor sleepiness. Patients with central hypersomnia were younger and sleepier than those without hypersomnia, but had similar levels of fatigue, disability, depression, cognitive performance, and frequencies of the human leukocyte antigen DQB1*0602 genotype. The severity of fatigue increased with higher depression scores, higher sleepiness severity, and lower sleep efficacy.

CONCLUSION

Central hypersomnias are frequent in MS when fatigue and sleepiness are present. Screening them through polysomnography studies is recommended.

Framing multiple sclerosis under a polysomnographic perspective

Multiple sclerosis (MS) is a mainly demyelinating, autoimmune, and disabling neurological disease. In addition to well-known clinically evident symptoms such as coordination or motor problems, increasing attention has been posed to a constellation of less evident symptoms significantly contributing to the clinical impact of MS. Among others, sleep symptoms have been only recently explored. This systematic review summarizes objective sleep findings detected by using polysomnography and their relationship with clinical variables in MS patients. While it is well known that sleep disorders are frequent in MS, objective clinical data are still scarce. Literature based on subjective reports indicate sleep disorders as highly frequent in MS patients; however, objective data are still scarce. New large case-control instrumental investigations are warranted to establish the real objective entity and impact of sleep comorbidities.

We need to do better: A systematic review and meta-analysis of diagnostic test accuracy of restless legs syndrome screening instruments

This systematic review and meta-analysis evaluated the diagnostic accuracy of screening instruments for restless legs syndrome (RLS) and reports sensitivity, specificity, positive (PPV) and negative predictive values (NPV). Searches for primary studies were conducted in electronic databases. Of the 1541 citations identified, 52 were included in the meta-analysis. The methodological quality of each study was evaluated using QUADAS-2. Only 14 studies assessed the reference standard in all participants or in all screen-positives and a selection of screen-negatives. Bivariate meta-analysis of these 14 studies estimated median sensitivity to be 0.88 (0.72-0.96) and specificity 0.90 (0.84-0.93); based on a population prevalence of 5%, the calculated PPV was 0.31 (0.27-0.34). For all 52 studies, with either full or partial verification of RLS status, we constructed best-case scenario sensitivities and specificities at pre-defined levels of prevalence: across all samples, when prevalence is 5%, the median best-case scenario PPV is 0.48 with significant between-study heterogeneity. No RLS screening instruments can currently be recommended for use without an expert clinical interview in epidemiological studies. For conditions with statistically low prevalence such as RLS, the specificity, not the sensitivity, of a screening instrument determines true prevalence. Therefore, future instruments should maximize specificity. We provide guidelines on RLS ascertainment in epidemiological studies that requires a two-step process with clinical interview following a screening test, and given the poor reporting quality of many RLS epidemiological studies, we include an RLS reporting checklist.

Restless Legs Syndrome in Multiple Sclerosis

Introduction

The co-existence of Restless Legs Syndrome/Willis-Ekbom Disease (RLS/WED/WED) and multiple sclerosis (MS) is a common condition. For this reason, we aimed to evaluate the effects of RLS/WED and its relationship with MS.

Methods

We evaluated the clinical features of 102 patients diagnosed with MS who were in follow-up between 2010 and 2015 in outpatient clinic. All the patients were evaluated for RLS/WED according to the revised International Restless Legs Syndrome Study Group (IRLSSG) diagnostic criteria. The Expanded Disability Status Scale (EDSS), Beck Depression Inventory, Beck Anxiety Inventory and Fatigue Severity Scale scores of all the patients were recorded. The IRLSSG 2003 severity scale was used to determine the degree of RLS/WED.

Results

RLS/WED was detected in 30.4% (n=31) of the patients (MS-RLS/WED+), but not in 69.6% (n=71) (MS-RLS/WED-). The mean EDSS score of the MS-RLS/WED+ patients were 3.2±2.1 while the MS-RLS/WED-patients were 2.0±1.6. The incidences of depression, moderate or severe anxiety, fatigue and intestinal and bladder dysfunction in the MS-RLS/WED+ patients were significantly higher. Regarding to RLS/WED complaints, 32.2% were mild, 35.4% were moderate, 19.3% were severe and 12.9% were very severe. When the MS subgroups were evaluated the highest RLS/WED severity score was found in the secondary progressive MS group. In the patients with pyramidal symptoms and intestinal and bladder dysfunction, the mean RLS/WED severity was significantly higher. The mean RLS/WED severity score was also significantly higher in those with depression and anxiety. The RLS/WED severity was significantly correlated with the number of pyramidal attacks and the EDSS score.

Conclusion

Restless legs syndrome is a cause of depression, anxiety and fatigue and has negative effects on MS patients. Therefore, after the diagnosis of MS, the RLS/WED symptoms and signs should be determined, as soon as possible, in addition to the other MS symptoms. The treatment of this condition should be started early.

[Frequent neurological diseases associated with the restless legs syndrome]

BACKGROUND

Restless legs syndrome (RLS) is a common neurological disease. Studies have shown that RLS is associated with a variety of medical and neurological disorders.

OBJECTIVES

Using the example of three associated neurological diseases, the significance for everyday therapy decisions is assessed.

MATERIAL AND METHODS

A systematic search was carried out in PubMed for all studies with the keyword "RLS" in combination with polyneuropathies (PNP), Parkinson's disease (PD) and multiple sclerosis (MS) and classified according to the methodology in high, medium or low study quality.

RESULTS

Of 16 studies on RLS and MS, 10 were rated as "high". The high association frequency of RLS in MS between 13.3% and 65.1% (the variability possibly originates from different methods) prevents further statements about the prevalence. Within 30 studies on Parkinson's disease 17 were classified as having a high quality. In patients with Parkinson disease RLS occurs most frequently during therapy and is related to the duration of dopaminergic treatment. In patients with polyneuropathy, only 5 out of 24 studies were classified as being of high quality and an increased RLS prevalence was detected for acquired polyneuropathies with heterogeneous data for hereditary forms.

CONCLUSION

There is an increased prevalence of association with RLS for the diseases discussed. This prevalence is possibly determined by the pathophysiology of these disorders. These diseases are possibly characterized by genetic predispositions as well, which can hopefully be classified more accurately in the future.

Impact, Frequency, and Severity of Restless Legs Syndrome in Patients with Multiple Sclerosis in Argentina

Background

Restless legs syndrome (RLS) frequency, and its association with depression, anxiety, sleep disorders, and fatigue, has not been previously studied in Latin American patients with multiple sclerosis (MS). We aimed to assess RLS frequency in patients with MS living in Argentina and to examine potential associations with depression, anxiety, and sleep disorders.

Methods

A cross-sectional study (n = 427) was conducted using a self-administered questionnaire, including International RLS Study Group criteria, to compare RLS frequency in patients with MS versus controls. The Hospital Anxiety and Depression Scale and the Fatigue Severity Scale were administered to all participants. Insomnia, excessive daytime somnolence, and other risk factors in patients with MS with RLS were analyzed using logistic regression.

Results

We included 189 patients with definite MS and 238 controls. The RLS frequency was 29.1% in patients with MS versus 13.0% in controls (odds ratio [OR] = 2.74, P = .00005). Moreover, clinically significant RLS (csRLS; ie, symptoms present ≥2 days per week) frequency was 19.4% in patients with MS versus 4.2% in controls (OR = 5.37, P < .00001). Longer MS duration and presence of anxiety, depression, insomnia, and smoking cigarettes were all significantly associated with RLS. Multivariate analysis showed that anxiety and fatigue were significantly associated with MS with RLS and MS with csRLS.

Conclusions

Both RLS and csRLS showed strong association with MS, supporting the need to screen for anxiety/depression, sleep quality, and fatigue in this patient population. We believe that identifying the presence and severity of these conditions would contribute to better MS management and treatment.

Achievements, challenges, and future perspectives of epidemiologic research in restless legs syndrome (RLS)

In the 20 years since the initial consensus on a common definition for restless legs syndrome (RLS), over 600 scientific reports on epidemiological aspects of RLS have been published. Most are descriptive and address important issues such as prevalence, familial patterns, comorbidities, and quality of life. While the establishment of prospective cohort studies and the use of secondary data sources are rather new to RLS research, both options significantly broaden the possibilities for analysis of disease risk factors. These two options, as well as the inclusion of a broader phenotyping of individual patients, have great potential to elucidate etiologic factors for RLS and expand knowledge about this common disorder. This article summarizes achievements in the area of RLS epidemiology, describes current challenges, and highlights future perspectives in the field.

The Neurological Sleep Index: A suite of new sleep scales for multiple sclerosis

Objective

The objective of this study was to develop patient-reported outcome measures for sleep dysfunction and sleepiness in multiple sclerosis (MS), since there are currently no MS-specific measurement tools for these clinically important entities.

Methods

Items were generated from semi-structured interviews followed by cognitive debrief. A 42-item pool was administered to patients with MS at three neuroscience centres in the UK. Comparator scales were co-administered. Constructs were validated by Rasch analysis, guided by initial exploratory factor analysis.

Results

There were two supraordinate qualitative themes of diurnal sleepiness and non-restorative nocturnal sleep. Rasch analysis on 722 records produced three scales, which corresponded to diurnal sleepiness, non-restorative nocturnal sleep and fragmented nocturnal sleep. All had excellent fit parameters, were unidimensional and were free from differential item functioning. A summed raw score cut-point of 31/48 in the Diurnal Sleepiness Scale equated to the standard cut-point of 10 on the Epworth Sleepiness Scale (ESS).

Conclusion

Three high-quality measurement scales were developed, and together they compose the Neurological Sleep Index for MS (NSI-MS). The Diurnal Sleepiness Scale might provide an alternative to the ESS. The Non-Restorative Nocturnal Sleep Scale and the Fragmented Nocturnal Sleep Scale appear to be the only such measures for use in MS.