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

A Case Report of Grave's Disease Presenting With an Episode of Restless Legs Syndrome

This case report explores a rare presentation of restless legs syndrome (RLS) in a 59-year-old female with a history of Graves' disease (GD), highlighting the diagnostic challenges and the importance of considering thyroid dysfunctions in RLS. The patient, previously diagnosed and treated for GD, presented with acute nocturnal discomfort in her lower limbs, along with symptoms of fatigue, weight loss, and palpitations. Physical examinations and thyroid function tests indicated a recurrence of GD. Her RLS symptoms notably resolved following the treatment of GD with methimazole, pointing towards secondary RLS induced by GD. This case emphasizes the necessity of a comprehensive diagnostic approach in RLS, particularly in differentiating it from mimicking conditions including leg cramps, arthritis, peripheral neuropathy, and drug-induced akathisia, and identifying underlying etiologies like thyroid dysfunctions. The resolution of RLS symptoms after GD treatment underlines the potential link between thyroid dysfunctions, iron metabolism, and the dopaminergic system in RLS pathophysiology.

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.

Thyroid Dysfunction and Sleep Disorders

Thyroid disorders and sleep disorders are common problems in the general population that can affect people of all ages, backgrounds, and sexes, but little is known about their clinical associations. We reviewed the literature assessing the associations between thyroid disease and sleep disorders and noted that hyperthyroidism and hypothyroidism have clinical overlap with sleep conditions such as insomnia, restless legs syndrome, and obstructive sleep apnea. These findings highlight the importance of identifying and managing thyroid dysfunction for patients with these common sleep disorders. Additional research is needed to further understand how thyroid dysfunction affects sleep physiology.