Periodic limb movements during REM sleep in multiple sclerosis: a previously undescribed entity

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%).

Determining Current Medications Usage within a Cohort of Patients in the UK-A Descriptive Retrospective Study

Swansea University's United Kingdom (UK) Multiple Sclerosis (MS) Register is a platform that contains information on more than 17,600 people with MS living in the UK. The register has been in operation since 2011 and represents comprehensive information about people living with MS in the UK. It is considered the first register of its kind that can link information from patients to clinical data and has been established to answer different information needs about MS. Aim: To elucidate the trends in patterns of medicines currently used by people with MS in the UK MS register. Methods: This study follows an exploratory descriptive design using the UK MS register as data resource. A number of 4516 people completed the EQ-5D survey out of 8736 people who have given their consent to answer online questionnaires which represents around 52% of the register total population. Descriptive analysis and tests were performed with SPSS to address the research objectives. Results: There are several medicine names entered by people with MS in their profiles. These medicines are used either to manage MS symptoms or to treat its associated complications. Among the medicine types revealed in this study, disease modifying drugs (DMDs), muscle relaxants, and anticonvulsants are the medicine types mainly used by people with MS followed by antidepressant and antianxiety medicines. Conclusions: From the antidepressants used most widely, amitriptyline was chosen as a subject medicine for further investigation in the remaining studies of this research due to its high frequency use, the elevated depression rates discovered among people with MS who seek information on it online, and the high online content noted on websites about this medicine.

Periodic limb movements during sleep: a narrative review

Objective

Using narrative review techniques, this paper evaluates the evidence for separable underlying patho-mechanisms of periodic limb movements (PLMs) to separable PLM motor patterns and phenotypes, in order to elucidate potential new treatment modalities.

Background

Periodic limb movement disorder (PLMD) is estimated to occur in 5–8% of the paediatric population and 4–11% of the general adult population. Due to significant sleep fragmentation, PLMD can lead to functional impairment, including hyperactivity and delayed language development in children, and poor concentration and work performance in adults. Longitudinal data demonstrate that those with PLMD are at greater risk of depression and anxiety, and a 4-fold greater risk of developing dementia. PLMD has been extensively studied over the past two decades, and several key insights into the genetic, pathophysiological, and neural correlates have been proposed. Amongst these proposals is the concept of separable PLM phenotypes, proposed on the basis of nocturnal features such as the ratio of limb movements and distribution throughout the night. PLM phenotype and presentation, however, varies significantly depending on the scoring utilized and the nocturnal features examined, across age, and co-morbid clinical conditions. Furthermore, associations between these phenotypes with major neurologic and psychiatric disorders remain controversial.

Methods

In order to elucidate potential divergent biological pathways that may help clarify important new treatment modalities, this paper utilizes narrative review and evaluates the evidence linking PLM motor patterns and phenotypes with hypothesised underlying patho-mechanisms. Distinctive, underlying patho-mechanisms include: a pure motor mechanism originating in the spinal cord, iron deficiency, dopamine system dysfunction, thalamic glutamatergic hyperactivity, and a more cortical-subcortical interplay. In support of the latter hypothesis, PLM rhythmicity appears tightly linked to the microarchitecture of sleep, not dissimilarly to the apnoeic/hypopneic events seen in obstructive sleep apnea (OSA).

Conclusions

This review closes with a proposal for greater investigation into the identification of potential, divergent biological pathways. To do so would require prospective, multimodal imaging clinical studies which may delineate differential responses to treatment in restless legs syndrome (RLS) without PLMS and PLMS without RLS. This could pave the way toward important new treatment modalities.

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.

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.

Restless legs syndrome among multiple sclerosis patients in Lebanon

BACKGROUND

Multiple sclerosis (MS) is often associated with fatigue, with an increased prevalence of sleep disorders compared to the general population, notably restless legs syndrome (RLS). The aim of this study was to evaluate the prevalence and severity of RLS as well the co-occurrence of spinal demyelination lesions in patients with MS in Lebanon.

METHODS

In this cross-sectional study, we consulted the MS database of the Lebanese association against Multiple Sclerosis and sent out questionnaires to 300 MS patients to screen then confirm the presence of RLS. The final sample included 28 MS participants with confirmed RLS. We conducted further questionnaires to collect demographic data, screen for comorbidities, gather spinal MRI results, and evaluate the severity of both diseases (using the EDSS and the JHRLSS).

RESULTS

Prevalence of RLS was 15% among MS patients in our study. 46.4% of RLS-affected MS patients had spinal cord demyelination lesions on their MRIs. Participants with MRI lesions had a lower severity score on the JHRLSS (p = 0.088). No association was found between the EDSS results and JHRLSS, demographic data, or comorbidities.

CONCLUSION

Restless legs syndrome is commonly found among patients with multiple sclerosis in Lebanon, is underdiagnosed, and ought to be systematically evaluated for in order to improve the patients' quality of life.

Contactless recording of sleep apnea and periodic leg movements by nocturnal 3-D-video and subsequent visual perceptive computing

Contactless measurements during the night by a 3-D-camera are less time-consuming in comparison to polysomnography because they do not require sophisticated wiring. However, it is not clear what might be the diagnostic benefit and accuracy of this technology. We investigated 59 persons simultaneously by polysomnography and 3-D-camera and visual perceptive computing (19 patients with restless legs syndrome (RLS), 21 patients with obstructive sleep apnea (OSA), and 19 healthy volunteers). There was a significant correlation between the apnea hypopnea index (AHI) measured by polysomnography and respiratory events measured with the 3-D-camera in OSA patients (r = 0.823; p < 0.001). The receiver operating characteristic curve yielded a sensitivity of 90% for OSA with a specificity of 71.4%. In RLS patients 72.8% of leg movements confirmed by polysomnography could be detected by 3-D-video and a significant moderate correlation was found between PLM measured by polysomnography and by the 3-D-camera (RLS: r = 0.654; p = 0.004). In total, 95.4% of the sleep epochs were correctly classified by the machine learning approach, but only 32.5% of awake epochs. Further studies should investigate, if this technique might be an alternative to home sleep testing in persons with an increased pre-test probability for OSA.

The Berlin Treatment Algorithm: recommendations for tailored innovative therapeutic strategies for multiple sclerosis-related fatigue

More than 80% of multiple sclerosis (MS) patients suffer from fatigue. Despite this, there are few therapeutic options and evidence-based pharmacological treatments are lacking. The associated societal burden is substantial (MS fatigue is a major reason for part-time employment or early retirement), and at least one out of four MS patients view fatigue as the most burdensome symptom of their disease. The mechanisms underlying MS-related fatigue are poorly understood, and objective criteria for distinguishing and evaluating levels of fatigue and tiredness have not yet been developed. A further complication is that both symptoms may also be unspecific indicators of many other diseases (including depression, sleep disorders, anemia, renal failure, liver diseases, chronic obstructive pulmonary disease, drug side effects, recent MS relapses, infections, nocturia, cancer, thyroid hypofunction, lack of physical exercise). This paper reviews current treatment options of MS-related fatigue in order to establish an individualized therapeutic strategy that factors in existing comorbid disorders. To ensure that such a strategy can also be easily and widely implemented, a comprehensive approach is needed, which ideally takes into account all other possible causes and which is moreover cost efficient. Using a diagnostic interview, depressive disorders, sleep disorders and side effects of the medication should be identified and addressed. All MS patients suffering from fatigue should fill out the Modified Fatigue Impact Scale, Epworth Sleepiness Scale, the Beck Depression Inventory (or a similar depression scale), and the Pittsburgh Sleep Quality Index (or the Insomnia Severity Index). In some patients, polygraphic or polysomnographic investigations should be performed. The treatment of underlying sleep disorders, drug therapy with alfacalcidol or fampridine, exercise therapy, and cognitive behavioral therapy-based interventions may be effective against MS-related fatigue. The objectives of this article are to identify the reasons for fatigue in patients suffering from multiple sclerosis and to introduce individually tailored treatment approaches. Moreover, this paper focuses on current knowledge about MS-related fatigue in relation to brain atrophy and lesions, cognition, disease course, and other findings in an attempt to identify future research directions.