Management Strategies for Restless Legs Syndrome/Willis-Ekbom Disease During Pregnancy

A comprehensive update on the ADMET considerations for α2δ calcium channel ligand medications for treating restless legs syndrome

INTRODUCTION

Restless legs syndrome/Willis-Ekbom disease (RLS/WED) is a sleep-related sensory-motor disorder associated with poor sleep quality and impaired daily functioning. In patients affected by chronic RLS/WED, a pharmacological therapy is recommended. International guidelines suggest to start the treatment with a α2δ calcium channel ligand in most cases, unless contraindicated.

AREAS COVERED

The present review is based on an extensive Internet and PubMed search from 1986 to 2024. Our purpose is to describe the absorption, distribution, metabolism, and toxicology (ADMET) of the α2δ ligands, with common consideration for the therapeutic class, specificities of different compounds, efficacy, and safety in relation to other treatment options.

EXPERT OPINION

α2δ ligands are quite similar in their ADMET profiles, sharing most of the pharmacokinetics and potential adverse effects. However, we highlight the linear kinetic of gabapentin enacarbil and pregabalin, differently from gabapentin. α2δ ligands are safe and effective for the treatment of RLS/WED. Additional benefits can be obtained in comorbid insomnia, chronic pain syndromes, history of impulse control disorder, and comorbid anxiety. The use of α2δ ligands is associated with poor risk of augmentation. We still need new long-term safe and effective treatments, which could be developed along with our knowledge of RLS/WED pathophysiology.

Restless legs syndrome: Over 50 years of European contribution

Restless legs syndrome (RLS) is a sensorimotor neurological disorder characterised by an urge to move the limbs with a circadian pattern (occurring in the evening/at night), more prominent at rest, and relieved with movements. RLS is one of the most prevalent sleep disorders, occurring in 5%-10% of the European population. Thomas Willis first described RLS clinical cases already in the 17th century, and Karl-Axel Ekbom described the disease as a modern clinical entity in the 20th century. Despite variable severity, RLS can markedly affect sleep (partly through the presence of periodic leg movements) and quality of life, with a relevant socio-economic impact. Thus, its recognition and treatment are essential. However, screening methods present limitations and should be improved. Moreover, available RLS treatment options albeit providing sustained relief to many patients are limited in number. Additionally, the development of augmentation with dopamine agonists represents a major treatment problem. A better understanding of RLS pathomechanisms can bring to light novel treatment possibilities. With emerging new avenues of research in pharmacology, imaging, genetics, and animal models of RLS, this is an interesting and constantly growing field of research. This review will update the reader on the current state of RLS clinical practice and research, with a special focus on the contribution of European researchers.

Prevalence and associated factors of restless leg syndrome (RLS) in Pakistani women during pregnancy

There is a dearth of literature studying restless leg syndrome (RLS) among pregnant patients in Pakistan. The objective of this study was to determine the prevalence and associated factors of RLS among pregnant Pakistani patients. It was conducted in 2018 among 478 women attending ante-natal check-up in the outpatient department of five hospitals in Karachi, Pakistan. Individuals were interviewed for socio-demographic information, the key criteria for RLS and its associated factors. RLS was reported in 54 (11%) individuals based on International Restless Legs Syndrome Study Group (IRLSSG) criteria. The mean age was 33.44 ± 4.42 years. Association between pregnant women with RLS and those without reveals statistically significant differences with increasing age (p=.01), gravida (p<.01) and para (p<.001). RLS was significant among working women (p=.001), during third trimester (p=.001), with insomnia (p<.001), use of tobacco (p<.001) and among women with gestational diabetes (p<.001), hypertension (p<.001). The study showed a low prevalence of RLS among women during pregnancy. It further reported gestational diabetes, hypertension, insomnia and tobacco use to be independently linked to RLS. Impact StatementWhat is already known on this subject? Pregnancy has been demonstrated to be strongly associated with development of secondary restless leg syndrome (RLS). RLS in pregnancy has also been shown to portend poor maternal and neonatal outcomes such as postpartum depression and preterm birth. Various conditions and lifestyle factors in pregnancy have been shown to be associated with the development of RLS, but there are variations in these across different populations.What do the results of this study add? The prevalence of RLS was only reported twice in pregnant patients in Pakistan and our research helps to address this data shortage. In addition, the results of our study document a strong association of RLS with gestational hypertension and gestational diabetes and also show that smoking and exercise were correlated with RLS during pregnancy, both of which were previously unstudied in the pregnant Pakistani population.What are the implications of these findings for clinical practice and/or further research? Demonstrating the prevalence of RLS in pregnant Pakistani patients highlights the need to screen these patients, particularly those with associated conditions identified in our findings, for RLS during antenatal visits and to treat their condition to improve maternal and neonatal outcomes.

Sleep Disturbance in Pregnancy

Sleep is vital to life, even when women enter into pregnancy state. Good sleep is important for a healthy pregnancy. Sleep disturbances are common during pregnancy and can be due to the change of pregnancy itself or the results of sleep disorders. There is growing evidence linking sleep disturbances with adverse maternal and fetal outcomes. Differentiation of sleep disorders in order to provide appropriate treatment as well as promoting good sleep for pregnant women is important. A multidisciplinary team to provide sleep care during antenatal period may be needed.

Iron deficiency in pregnancy: Influence on sleep, behavior, and molecular markers of adult male offspring

Iron restriction during pregnancy can lead to iron deficiency and changes in the dopaminergic system in the adulthood of offspring, and restless legs syndrome (RLS) is closely related to these changes. Objectives: Analyze whether iron restriction during pregnancy would cause changes in the behavior, sleep, and dopaminergic system of the male offspring. In addition, we aimed to assess whether exercise would be able to modulate these variables. The pregnant rats (Wistar) were divided into four groups with different concentrations of iron in the diet: standard (St), supplementation (Su), restriction since weaning (R1), and restriction only during pregnancy (R2). After birth, the offspring were assigned to their respective groups according to the dams diet (St, Su, R1, and R2) and distributed into sedentary (SD) and exercised (EX) (for 8 weeks of training), reaching eight groups of offspring (O): OSt SD, OSt EX, OSu SD, OSu EX, OR1 SD, OR1 EX, OR2 SD, and OR2 EX. Sleep, behavior, and analysis of key genes of dopaminergic system (D2, DAT) were performed after 8 weeks. The results for trained offspring that the mother received supplementation diet were the most expressive, with increased freezing and the OR1 SD group showed an increase in DAT protein content. These changes may have been due to the association between the dams diet during pregnancy and the practice of exercise by the offspring. The different concentrations of iron during pregnancy caused changes in the offspring, however, they were not associated with fetal programming in the context of RLS.

The Management of Restless Legs Syndrome: An Updated Algorithm

Restless legs syndrome (RLS) is a common disorder. The population prevalence is 1.5% to 2.7% in a subgroup of patients having more severe RLS with symptoms occurring 2 or more times a week and causing at least moderate distress. It is important for primary care physicians to be familiar with the disorder and its management. Much has changed in the management of RLS since our previous revised algorithm was published in 2013. This updated algorithm was written by members of the Scientific and Medical Advisory Board of the RLS Foundation based on scientific evidence and expert opinion. A literature search was performed using PubMed identifying all articles on RLS from 2012 to 2020. The management of RLS is considered under the following headings: General Considerations; Intermittent RLS; Chronic Persistent RLS; Refractory RLS; Special Circumstances; and Alternative, Investigative, and Potential Future Therapies. Nonpharmacologic approaches, including mental alerting activities, avoidance of substances or medications that may exacerbate RLS, and oral and intravenous iron supplementation, are outlined. The choice of an alpha₂-delta ligand as first-line therapy for chronic persistent RLS with dopamine agonists as a second-line option is explained. We discuss the available drugs, the factors determining which to use, and their adverse effects. We define refractory RLS and describe management approaches, including combination therapy and the use of high-potency opioids. Treatment of RLS in pregnancy and childhood is discussed.

Zinc and Magnesium Levels of Pregnant Women with Restless Leg Syndrome and Their Relationship with Anxiety: A Case-Control Study

Restless leg syndrome (RLS) is a multifactorial movement disorder, and pregnancy is seen as a risk factor. This study aims to determine the clinical and psychiatric causes of RLS with a case-control study. The hemogram, biochemistry data, thyroid function tests, and serum element levels of healthy pregnant women (n = 134) and pregnant women diagnosed with RLS (n = 119) were compared. Total Ca, Mg, K, and Na concentrations were measured with an inductively coupled plasma optical emission spectrometry (ICP-OES), and an atomic absorption spectrophotometer was used to measure total concentrations of Zn in all samples. The Beck Anxiety Inventory (BAI), the Beck Depression Inventory (BDI), and the Pittsburg Sleep Quality Index (PSQI) scores were also compared in both groups. Sonographic measurements showed that the fetal biparietal diameter and femur lengths were higher in the RLS group (p = 0.001, p = 0.048, respectively), and abortion history was higher in the RLS group (p = 0.016). Magnesium and zinc levels were lower (p < 0.001 for both) and BAI and PSQI scores were higher (p < 0.001 for both) in the RLS group, and there was no difference between the BDI (p = 0.269) scores. A statistically significant relationship was detected between the BAI and RLS scores in the control and RLS groups (p < 0.001 for both). This is the first study to show that magnesium and zinc deficiency may play a role in the etiology of RLS during pregnancy; the results also showed adverse perinatal outcomes such as high miscarriage.

The prevalence of Restless Legs Syndrome/Willis-ekbom disease (RLS/WED) in the third trimester of pregnancy: a systematic review

Background

RLS is known as one of the most common movement disorders during pregnancy, which is most aggravated in the third trimester of pregnancy and can affect up to one-third of pregnant women. This study intends to determine the total prevalence of RLS in the third trimester of pregnancy through a systematic review.

Methods

The present study was conducted via meta-analysis method up to 2019. The papers related to the subject of interest were obtained through searching in SID, MagIran, IranDoc, Scopus, Embase, Web of Science (ISI), PubMed, Science Direct, and Google Scholar databases. Heterogeneity of the studies was examined via I² index, and the data were analyzed in Comprehensive meta-analysis software.

Results

In investigating 10 papers capturing 2431 subjects within the age range of 25–39 years, the total prevalence of RLS in the third trimester of pregnancy based on meta-analysis was obtained as 22.9% (95% CI: 14.7–33.8%). Further, as the sample size increased, the RLS prevalence diminished, while with increase in years, this prevalence increased, where this difference was statistically significant (P < 0.05).

Conclusion

Prevalence of RLS in the third trimester of pregnancy is high, healthcare policymakers should organize educational classes to improve the life dimensions among this group of pregnant women.

Movement disorders in pregnancy

Movement disorders in women during pregnancy are uncommon. Therefore, high quality studies are limited, and guidelines are lacking for the treatment of movement disorders in pregnancy, thus posing a significant therapeutic challenge for the treating physicians. In this chapter, we discuss movement disorders that arise during pregnancy and the preexisting movement disorders during pregnancy. Common conditions encountered in pregnancy include but are not limited to restless legs syndrome, chorea gravidarum, Parkinson disease, essential tremor, and Huntington disease as well as more rare movement disorders (Wilson's disease, dystonia, etc.). This chapter summarizes the published literature on movement disorders and pharmacologic and surgical considerations for neurologists and physicians in other specialties caring for patients who are pregnant or considering pregnancy.