Transient Willis-Ekbom's disease (restless legs syndrome) during pregnancy may be caused by estradiol-mediated dopamine overmodulation

Common sleep disorders in pregnancy: a review

In this review, we provide a comprehensive overview of common sleep disorders during pregnancy, including their characterization, prevalence, risk factors, and possible contribution to maternal and fetal outcomes. We conducted a quasi-systematic literature search of the MEDLINE database and identified 744 studies from 1991 through 2021, inclusive, that met our inclusion criteria. We synthesized the existing literature on sleep disorders during pregnancy and highlighted controversies, research gaps, and needed clinical developments. Our review covers a range of sleep disorders, including insomnia, obstructive sleep apnea, restless legs syndrome, and circadian rhythm disorders. We discuss the prevalence of these disorders in pregnancy and their potential impact on maternal and fetal health outcomes. We also explore the relationship between sleep disorders, pre-pregnancy comorbidities such as obesity, and pregnancy-related conditions such as gestational diabetes mellitus and preeclampsia. In addition to summarizing the existing literature on sleep disorders during pregnancy, we also highlight opportunities for further research in this area. We suggest that future studies should strive to employ validated and objective measurement tools for sleep disorders and prioritize utilization of longitudinal methods with participant follow-up through postpartum, mid-life, menopause, and beyond. We also put forward investigation into the impact of circadian rhythm disruption on reproductive physiology and early pregnancy outcomes as an area of important work. Overall, our review provides valuable insights on sleep and reproduction and into common sleep disorders during pregnancy and their potential impact on maternal and fetal health outcomes.

Association between thyroid function and disease severity in restless legs syndrome

Background

Restless Legs Syndrome (RLS) is a common neurological disorder. Growing evidence shows that dopaminergic dysfunction and iron deficiency are associated with the pathogenesis of RLS. Additionally, the dopaminergic system is linked with the hypothalamic-pituitary-thyroid (HPT) axis. Thus, the current study aimed to compare thyroid function between RLS patients and healthy subjects and investigate the associations with clinical characteristics of RLS.

Methods

Serum levels of thyroid hormones were investigated in 102 first-episode drug-naïve RLS patients and 80 matched healthy controls (HCs). Baseline data and clinical characteristics were performed by professional personnel. In addition, multivariate regression was used to analyze the relationship between thyroid function and RLS.

Results

Compared with control group, RLS patients had significantly higher serum thyroid-stimulating hormone (TSH) levels (p < 0.001), and higher prevalence of subclinical hypothyroidism [Odds ratio (OR) 8.00; 95% confidence interval (CI) = 3.50–18.30; p < 0.001]. The Subclinical hypothyroidism rate (47.1 vs. 10%, p < 0.001) in RLS patients was higher than the HCs group. Regression analysis revealed that serum TSH (OR = 1.77; 95% CI = 1.41–2.23; p < 0.001) was independently associated with RLS. There was a statistically significant positive correlation between TSH and the Pittsburgh sleep quality index (PSQI) scores (r = 0.728, p < 0.001), and the International Restless Legs Scales (IRLS) points (r = 0.627, p < 0.001). Spearman correlation analysis showed that FT₃ was positive correlated with HAMA₁₄ score (r = 0.239, p = 0.015). In addition, compared with the good-sleeper group, poor-sleeper patients had significantly higher serum TSH levels (p < 0.001).

Conclusion

Serum levels of TSH and the prevalence of subclinical hypothyroidism were higher in RLS patients, indicating the imbalance between thyroid hormones (TH) and the dopaminergic system may contribute to the development of primary RLS. Additionally, the TH axis may influence the quality of sleep in RLS patients.

Restless Legs Syndrome, and symptoms of Restless Syndrome in patients with Graves' disease: a cross-sectional survey

OBJECTIVES

Restless legs syndrome (RLS) is a frequent comorbid condition associated with distinct unrelated diseases. While the incidence of RLS has not been definitively confirmed, RLS-like symptoms have been reported in a section of Asian population who also had hyperthyroidism. The prevalence of RLS is generally low in Asian populations. Under these circumstances, we hypothesized that in a population where RLS is common, such as in Brazil, RLS could manifest as a comorbid ailment alongside Graves' disease, a common hyperthyroid condition.

METHODS

In a cross-sectional survey, 108 patients who presented with Graves' disease were analyzed for restless legs or associated symptoms.

RESULTS

Twelve patients (11.1%) displayed symptoms of RLS prior to the incidence of Graves' disease. These patients experienced worsening of the symptoms during their hyperthyroid state. Six patients (5.6%) developed RLS, consequent upon the incidence of Graves' disease as per the consensus of the panel of the experts. Fifteen patients (13.9%) also presented with RLS-like symptoms without any discernible circadian feature of the syndrome.

CONCLUSION

Our findings confirm that Graves' disease might trigger restless legs-like symptoms, while the condition of hyperthyroidism could also be complicated by definite RLS.

Restless Legs Syndrome: From Pathophysiology to Clinical Diagnosis and Management

Restless legs syndrome (RLS), a common neurological sensorimotor disorder in western countries, has gained more and more attention in Asian countries. The prevalence of RLS is higher in older people and females. RLS is most commonly related to iron deficiency, pregnancy and uremia. The RLS symptoms show a significant circadian rhythm and a close relationship to periodic limb movements (PLMs) in clinical observations, while the pathophysiological pathways are still unknown. The diagnostic criteria have been revised in 2012 to improve the validity of RLS diagnosis. Recent studies have suggested an important role of iron decrease of brain in RLS pathophysiology. Dopaminergic (DA) system dysfunction in A11 cell groups has been recognized long ago from clinical treatment and autopsy. Nowadays, it is believed that iron dysfunction can affect DA system from different pathways and opioids have a protective effect on DA system. Several susceptible single nucleotide polymorphisms such as BTBD9 and MEIS1, which are thought to be involved in embryonic neuronal development, have been reported to be associated with RLS. Several pharmacological and non-pharmacological treatment are discussed in this review. First-line treatments of RLS include DA agents and α2δ agonists. Augmentation is very common in long-term treatment of RLS which makes prevention and management of augmentation very important for RLS patients. A combination of different types of medication is effective in preventing and treating augmentation. The knowledge on RLS is still limited, the pathophysiology and better management of RLS remain to be discovered.

Consensus clinical practice guidelines for the diagnosis and treatment of restless legs syndrome/Willis-Ekbom disease during pregnancy and lactation

Restless legs syndrome (RLS)/Willis-Ekbom disease (WED) is common during pregnancy, affecting approximately one in five pregnant women in Western countries. Many report moderate or severe symptoms and negative impact on sleep. There is very little information in the medical literature for practitioners on the management of this condition during pregnancy. Accordingly, a task force was chosen by the International RLS Study Group (IRLSSG) to develop guidelines for the diagnosis and treatment of RLS/WED during pregnancy and lactation. A committee of nine experts in RLS/WED and/or obstetrics developed a set of 12 consensus questions, conducted a literature search, and extensively discussed potential guidelines. Recommendations were approved by the IRLSSG executive committee, reviewed by IRLSSG membership, and approved by the WED Foundation Medical Advisory Board. These guidelines address diagnosis, differential diagnosis, clinical course, and severity assessment of RLS/WED during pregnancy and lactation. Nonpharmacologic approaches, including reassurance, exercise and avoidance of exacerbating factors, are outlined. A rationale for iron supplementation is presented. Medications for RLS/WED are risk/benefit rated for use during pregnancy and lactation. A few are rated "may be considered" when RLS/WED is refractory to more conservative approaches. An algorithm summarizes the recommendations. These guidelines are intended to improve clinical practice and promote further research.

Sleep disorders: A review of the interface between restless legs syndrome and iron metabolism

Restless legs syndrome (RLS) is characterized by unpleasant sensations mainly in the legs. 43% of RLS-associated conditions have also been associated with systemic iron deficiency. The objective of this study was to review in the literature the relationship between iron metabolism and RLS. With an initial search using the keywords combination “Iron Metabolism OR Iron Deficiency AND Restless Legs Syndrome,” 145 articles were screened, and 20 articles were selected. Few studies were found for this review in the period of 2001–2014, however, the correlation between RLS and iron was evident.

Pre-pregnancy restless legs syndrome (Willis-Ekbom Disease) is associated with perinatal depression

OBJECTIVES

Both restless legs syndrome ([RLS], also known as Willis-Ekbom Disease [WED]) and depression are common during pregnancy. However, no prior studies have assessed if pregnant women with RLS have an elevated risk of depression during and/or after pregnancy.

METHODS

1,428 women who were pregnant in gestational week 16-17 were asked to participate in a longitudinal survey. They were followed by web-based questionnaires in gestational week 17 and 32, and 6 weeks after delivery. Data were also retrieved from prenatal and birth records. Two different sets of criteria were used to examine the prevalence of RLS in the cohort (International Restless Legs Syndrome Society Group standard criteria and the later developed CH-RLSQ11 questionnaire). The latter questionnaire attempts to exclude those with common "mimics" of RLS.

RESULTS

Adjusted odds ratio for depression in gestational week 17, 32, and postpartum week 6 in relation to pre-pregnancy RLS onset and moderate to severe symptom severity were 4.74 (2.30 - 9.76), 3.67 (1.85 - 7.28), and 2.58 (1.28 - 5.21), respectively. No significant associations were seen in pregnant women with de novo RLS during pregnancy. When using the standard diagnostic RLS criteria and frequency of symptoms more than 2-3 days per week, the prevalence of RLS was 12.3%. With the CH-RLSQ11 questionnaire and the same threshold for frequency of symptoms the prevalence was 6.5%.

CONCLUSION

Women with RLS onset before pregnancy with moderate or severe symptoms had an increased risk of both antenatal and postnatal depression. The self-reported prevalence of RLS during pregnancy is lower when a questionnaire dealing with "mimics" is used.

Restless legs syndrome and pregnancy: a review

Restless legs syndrome (RLS) is a common sensorimotor neurological disorder that is diagnosed according to the revised criteria of the International RLS Study Group (IRLSSG). The pathophysiology of RLS is still unknown and its prevalence is influenced by ethnicity, age, and gender. RLS is divided into two types by etiology: primary or idiopathic and secondary. Primary RLS is strongly influenced by a genetic component while secondary RLS is caused by other associated conditions such as end-stage renal disease or peripheral neuropathy. Another common condition associated with RLS is pregnancy. The prevalence of RLS during pregnancy is two to three times higher than in the normal population and is influenced by the trimester and the number of parity. The main mechanisms that may contribute to the pathophysiology of RLS during pregnancy are hormonal changes and iron and folate status. Standard medications for treating RLS during pregnancy are not established. Most medications have been used according to the evidence from non-pregnant patients. Therefore, consideration of the medical treatment for treating RLS during pregnancy should be balanced between the benefit of relieving the symptoms and maternal and fetal risk. In general, the prognosis of RLS during pregnancy is good and symptoms are usually relieved after delivery.

17β-estradiol delays 6-OHDA-induced apoptosis by acting on Nur77 translocation from the nucleus to the cytoplasm

Nuclear receptors (Nurs) represent a large family of gene expression regulating proteins. Gathering evidence indicates an important role for Nurs as transcription factors in dopamine neurotransmission. Nur77, a member of the Nur superfamily, plays a role in mediating the effects of antiparkinsonian and neuroleptic drugs. Besides, Nur77 survival and apoptotic roles depend largely on its subcellular localization. Estrogens are known for their neuroprotective properties, as demonstrated in animal and clinical studies. However, their action on Nur77 translocation pertaining to neuroprotection has not been investigated yet. The aim of our study was to perform a kinetic study on the effect of neurotoxic 6-hydroxydopamine (6-OHDA) and 17β-estradiol (E2) on the subcellular localization of Nur77 with reference to the modulation of apoptosis in PC12 cells. Our results demonstrate that E2 administration alone does not affect Nur77 cytoplasmic/nuclear ratio, mRNA levels, or apoptosis in PC12 cells. The neurotoxin 6-OHDA significantly enhances cytoplasmic localization of Nur77 after merely 3 h, while precipitating apoptosis. 6-OHDA also increases Nur77 transcription, which could partly explain the rise in cytoplasmic localization of the protein. Finally, treatment with both E2 and 6-OHDA delays Nur77 accumulation in the cytoplasm and delays cell death for a few hours in our cellular paradigm. Pre-treatment with E2 does not alter the increase in levels of Nur77 mRNA produced by 6-OHDA, suggesting that a raise in nuclear translocation is likely responsible for the stabilization of the cytoplasmic/nuclear ratio until 6 h. These results suggest an intriguing cooperation between E2 and Nur77 toward cellular fate guidance.