Restless legs syndrome in subjects with a knee prosthesis: evidence that symptoms are generated in the periphery

Is Restless Legs Syndrome De Facto Thyroid Disease?

While a primary role in the pathogenesis of restless legs syndrome (RLS) has been attributed to dysfunction of the dopaminergic system and impaired iron metabolism (particularly in the central nervous system), it has been hypothesized that an imbalance between thyroid hormones and dopaminergic activity may be the starting point for all aspects of RLS. Although this hypothesis was proposed more than a decade ago, it has not yet been verified beyond doubt. The main aim of this study is to compare the prevalence of RLS in a population of patients with the most common thyroid gland diseases with a population of individuals with a healthy thyroid gland. The study included 237 participants divided into smaller groups according to the thyroid disease concerning them. Each participant had a laboratory diagnosis, an ultrasound scan and an assessment of the fulfilment of RLS criteria according to the International Restless Legs Syndrome Study Group (IRLSSG) criteria. The results obtained were subjected to statistical analysis. RLS is significantly more common in patients with known thyroid disease; Hashimoto’s disease, among others, manifests a 2.56× higher risk of a positive diagnosis for RLS than the general population. The association of RLS with thyroid disease is notable, although it is difficult to conclude unequivocally that there is a cause-and-effect relationship between the two. Further investigation into a potentially autoimmune cause of restless legs syndrome should be considered.

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.

Pramipexole-responsive acute restless arms syndrome after surgery under general anesthesia: Case report and literature review

We reported a case of acute restless arms syndrome occurring after colorectal surgery under general anaesthesia. This case was also compared with other cases of restless legs/arms syndromes occurring in a perioperative context through a literature review. As the restless legs syndrome, the restless arms syndrome can be exacerbated by perioperative procedures and improved with pramipexole from the first day of treatment. This case reinforces the idea that the restless arms syndrome seems to be subsumed along with the restless legs syndrome, and is a further argument to use the diagnosis term "restless limb syndrome" for the restlessness of any limb with clinical features similar to the restless legs syndrome.

Saint John's wort, an herbal inducer of the cytochrome P4503A4 isoform, may alleviate symptoms of Willis-Ekbom's disease

OBJECTIVE

Certain drug classes alleviate the symptoms of Willis-Ekbom's disease, whereas others aggravate them. The pharmacological profiles of these drugs suggest that drugs that alleviate Willis-Ekbom's disease inhibit thyroid hormone activity, whereas drugs that aggravate Willis-Ekbom's disease increase thyroid hormone activity. These different effects may be secondary to the opposing actions that drugs have on the CYP4503A4 enzyme isoform. Drugs that worsen the symptoms of the Willis-Ekbom's disease inhibit the CYP4503A4 isoform, and drugs that ameliorate the symptoms induce CYP4503A4. The aim of this study is to determine whether Saint John's wort, as an inducer of the CYP4503A4 isoform, diminishes the severity of Willis-Ekbom's disease symptoms by increasing the metabolism of thyroid hormone in treated patients.

METHODS

In an open-label pilot trial, we treated 21 Willis-Ekbom's disease patients with a concentrated extract of Saint John's wort at a daily dose of 300 mg over the course of three months.

RESULTS

Saint John's wort reduced the severity of Willis-Ekbom's disease symptoms in 17 of the 21 patients.

CONCLUSION

Results of this trial suggest that Saint John's wort may benefit some Willis-Ekbom's disease patients. However, as this trial was not placebo-controlled, the extent to which Saint John's wort is effective as a Willis-Ekbom's disease treatment will depend on future, blinded placebo-controlled studies.

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

Willis-Ekbom's disease (WED), formerly called restless legs syndrome, is more common in pregnant than in non-pregnant women, implying that the physiological and biochemical changes during pregnancy influence its development. During pregnancy, many hormone levels undergo significant changes, and some hormones significantly increase in activity and can interfere with other hormones. For example, the steroid hormone estradiol interferes with the neuroendocrine hormone dopamine. During pregnancy, the activity of the thyroid axis is enhanced to meet the increased demand for thyroid hormones during this state. Dopamine is a neuroendocrine hormone that diminishes the levels of thyrotropin and consequently of thyroxine, and one of the roles of the dopaminergic system is to counteract the activity of thyroid hormones. When the activity of dopamine is not sufficient to modulate thyroid hormones, WED may occur. Robust evidence in the medical literature suggests that an imbalance between thyroid hormones and the dopaminergic system underpins WED pathophysiology. In this article, we present evidence that this imbalance may also mediate transient WED during pregnancy. It is possible that the main hormonal alteration responsible for transient WED of pregnancy is the excessive modulation of dopamine release in the pituitary stalk by estradiol. The reduced quantities of dopamine then cause decreased modulation of thyrotropin, leading to enhanced thyroid axis activity and subsequent WED symptoms. Iron deficiency may also be a predisposing factor for WED during pregnancy, as it can both diminish dopamine and increase thyroid hormone.