Restless legs syndrome

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.

Polysomnography findings in sleep-related eating disorder: a systematic review and case report

Background

Sleep-related eating disorder (SRED) consists of recurrent episodes of uncontrolled, involuntary eating and drinking 1-3 h after falling asleep with partial or full unconsciousness. This condition is diagnosed based on interviews with the patients affected and the diagnostic criteria of the International Classification of Sleep Disorders. However, polysomnography (PSG) is not necessary to confirm this disease. This systematic review aims to evaluate the findings of PSG in SRED patients.

Methods

For this systematic review, PubMed, Embase, and Scopus databases were searched in February 2023, which resulted in 219 records. After removing duplicates, the articles that included the presentation of PSG results of SRED patients in English were selected. In addition, only original studies were considered. The risk of bias by using case reports and descriptive studies was assessed using the Joanna Briggs Institute critical appraisal tools and the Risk of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool. Furthermore, a case report of a 66-year-old woman with SRED was included.

Results

A total of 15 papers were selected for further analysis, of which 7 were descriptive studies, 6 were case reports, and 2 were observational studies. The risk of bias in the majority of the studies was moderate or high. Unexpectedly, if the eating episode occurred during PSG, in most cases it was not observed during deep sleep (the N3 sleep stage). Moreover, studies did not report significant deviations in the sleep parameters measured using PSG. Among SRED patients, the prevalence of sleepwalking was much higher than the general population. Our case report presented a potentially life-threatening episode of holding an apple in the mouth that might result in choking, which was captured using PSG.

Conclusion

Polysomnography is not necessary for the diagnosis of SRED. However, it could facilitate the diagnosis and differentiation of SRED from other eating disorders. PSG also has limitations in capturing eating episodes and in addition, its cost effectiveness should be considered during the diagnostic process. More studies into the pathophysiology of SRED are needed because classifying SRED as non-rapid eye movement parasomnias can be inappropriate as it does not always occur during deep sleep.

Neurological Sleep Disorders and Blood Pressure: Current Evidence

Hypertension is a major determinant of cardiovascular morbidity and mortality and is highly prevalent in the general population. While the relationship between sleep apnea and increased blood pressure has been well documented, less recognized is emerging evidence linking sleep-related movement disorders such as restless legs syndrome/periodic limb movements of sleep and sleep-related bruxism with blood pressure (BP) dysregulation and hypertension. There is also recent literature linking narcolepsy-cataplexy with elevated BP and altered pressor responses, and there are data suggesting abnormal BP control in rapid eye movement sleep behavior disorder. It is thought that neural circulatory mechanisms, sympathetic activation in particular, comprise the predominant mediator underlying elevated BP in these neurological sleep disorders. There is very limited evidence that treating these sleep disorders may be beneficial in lowering BP primarily because this question has received very little attention. In this review, we discuss the potential pathophysiologic mechanisms underlying elevated BP in restless legs syndrome/periodic limb movements of sleep, sleep-related bruxism, narcolepsy-cataplexy, and rapid eye movement sleep behavior disorder. We also examine the relationship between these sleep disorders and elevated BP and the impact of treatment of these conditions on BP control. Last, we discuss gaps in the literature evaluating the associations between these sleep disorders and elevated BP and identify areas for further research.

Presynaptic dopaminergic terminal imaging and non-motor symptoms assessment of Parkinson's disease: evidence for dopaminergic basis?

Parkinson's disease (PD) is now considered to be a multisystemic disorder consequent on multineuropeptide dysfunction including dopaminergic, serotonergic, cholinergic, and noradrenergic systems. This multipeptide dysfunction leads to expression of a range of non-motor symptoms now known to be integral to the concept of PD and preceding the diagnosis of motor PD. Some non-motor symptoms in PD may have a dopaminergic basis and in this review, we investigate the evidence for this based on imaging techniques using dopamine-based radioligands. To discuss non-motor symptoms we follow the classification as outlined by the validated PD non-motor symptoms scale.

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.

Association between restless legs syndrome and CLOCK and NPAS2 gene polymorphisms in schizophrenia

Previous studies have suggested that there is a genetic basis to restless legs syndrome (RLS) development. Occurrence of antipsychotic-induced RLS could also be due to differences in genetic susceptibility. We investigated whether CLOCK and NPAS2 gene polymorphisms are associated with RLS in schizophrenic patients on antipsychotics because RLS symptoms usually manifest during the evening and night. We assessed symptoms of RLS in 190 Korean schizophrenic patients on antipsychotics and divided the subjects into two groups according to the International Restless Legs Syndrome Study Group diagnostic criteria: (i) subjects who met all the criteria and (ii) the remaining subjects who did not meet all the criteria. We found a significant difference in the number of subjects with different genotype and allele carrier frequencies for the CLOCK gene (rs2412646) between the two groups (p = 0.031 and 0.010, respectively). Distribution of CLOCK haplotypes (rs2412646-rs1801260) was significantly different between schizophrenic patients with and without RLS (p = 0.021). However, the distributions of allelic, genotypic, and haplotypic variants of NPAS2 (rs2305160 and rs6725296) were not significantly different between the two groups. Our results suggest that CLOCK polymorphisms are associated with increased susceptibility of schizophrenic patients to RLS. We hypothesize that RLS in schizophrenia patients treated with antipsychotics may be a very mild akathisia that manifests during the night and is under control of circadian oscillation.

Restless legs syndrome as the initial presentation of multiple sclerosis

The restless legs syndrome (RLS) is a common central nervous system disorder. It is characterized by complaints of unpleasant sensation in the legs occurring during periods of leg inactivity which worsen or only occur in the evening or at night and relieved partially or totally by movement. The RLS may be idiopathic or due to secondary causes. It is associated with several pathological or physiological conditions. Iron metabolism and dysfunctions of the dopaminergic system are the most important factors in the pathophysiology. There are several studies suggesting multiple sclerosis as one of the causes of symptomatic RLS. Here, we report a case of RLS as the initial presentation of MS. The sudden onset of RLS symptoms in our patient suggested the possibility of an underlying cause. His diagnostic evaluation excluded other causes of RLS and his clinical course suggested that RLS was due to MS. MS with the spinal cord involvement is mostly associated with RLS, but any lesion in the hypothalamic-spinal connection may cause disinhibition of lower spinal levels, resulting in RLS. RLS as the initial presentation of MS reflects that the pathophysiology of RLS in MS is related to inflammatory demyelination rather than axonal degeneration.

Modeling the genetic basis for human sleep disorders in Drosophila

Sleep research in Drosophila is not only here to stay, but is making impressive strides towards helping us understand the biological basis for and the purpose of sleep—perhaps one of the most complex and enigmatic of behaviors. Thanks to over a decade of sleep-related studies in flies, more molecular methods are being applied than ever before towards understanding the genetic basis of sleep disorders. The advent of high-throughput technologies that can rapidly interrogate whole genomes, epigenomes and proteomes, has also revolutionized our ability to detect genetic variants that might be causal for a number of sleep disorders. In the coming years, mutational studies in model organisms such as Drosophila will need to be functionally connected to information being generated from these whole-genome approaches in humans. This will necessitate the development of appropriate methods for interpolating data and increased analytical power to synthesize useful network(s) of sleep regulatory pathways—including appropriate discriminatory and predictive capabilities. Ultimately, such networks will also need to be interpreted in the context of fundamental neurobiological substrates for sleep in any given species. In this review, we highlight some emerging approaches, such as network analysis and mathematical modeling of sleep distributions, which can be applied to contemporary sleep research as a first step to achieving these aims. These methodologies should favorably impact not only a mechanistic understanding of sleep, but also future pharmacological intervention strategies to manage and treat sleep disorders in humans.

Periodic leg movements in sleep in elderly patients with Parkinsonism and Alzheimer's disease

BACKGROUND

  Periodic leg movements in sleep (PLMS) are non-epileptiform, repetitive movements of the lower limbs that have been associated with apparent dopamine deficiency. We hypothesized that elderly patients with a disease characterized primarily by dopamine depletion (Parkinsonism) would have higher rates of PLMS than age-matched controls or a different neurodegenerative condition not primarily involving a hypodopaminergic state, Alzheimer's disease (AD).

METHODS

  We compared rates of PLMS derived from in-laboratory overnight polysomnography in patients with Parkinsonism (n = 79), AD (n = 28), and non-neurologically impaired, community-based controls (n = 187).

RESULTS

  Patients with Parkinsonism not receiving levodopa had significantly higher rates of PLMS than did patients with Parkinsonism receiving levodopa as well as higher rates than seen in AD and controls. Other medications did not appear to exert the pronounced effect of levodopa on PLMS in this Parkinsonian patient population. The symptom of leg kicking was reported more frequently in Parkinsonism and was associated with higher rates of PLMS. Caregiver reported leg kicking was unrelated to PLMS in AD.

CONCLUSIONS

 Results are broadly compatible with a dopaminergic hypothesis for PLMS in Parkinsonism. The clinical significance of the negative findings in patients with AD requires further investigation.

Sleep fragmentation and motor restlessness in a Drosophila model of Restless Legs Syndrome

Restless Legs Syndrome (RLS), first chronicled by Willis in 1672 and described in more detail by Ekbom in 1945, is a prevalent sensorimotor neurological disorder (5%-10% in the population) with a circadian predilection for the evening and night. Characteristic clinical features also include a compelling urge to move during periods of rest, relief with movement, involuntary movements in sleep (viz., periodic leg movements of sleep), and fragmented sleep. Although the pathophysiology of RLS is unknown, dopaminergic neurotransmission and deficits in iron availability modulate expressivity. Genome-wide association studies have identified a polymorphism in an intronic region of the BTBD9 gene on chromosome 6 that confers substantial risk for RLS. Here, we report that loss of the Drosophila homolog CG1826 (dBTBD9) appreciably disrupts sleep with concomitant increases in waking and motor activity. We further show that BTBD9 regulates brain dopamine levels in flies and controls iron homeostasis through the iron regulatory protein-2 in human cell lines. To our knowledge, this represents the first reverse genetic analysis of a "novel" or heretofore poorly understood gene implicated in an exceedingly common and complex sleep disorder and the development of an RLS animal model that closely recapitulates all disease phenotypes.