Symptom Severity of Restless Legs Syndrome Predicts Its Clinical Course

Restless Legs Syndrome and Periodic Limb Movements of Sleep: From Neurophysiology to Clinical Practice

SUMMARY

This article summarizes restless legs syndrome (RLS), periodic limb movements of sleep, and periodic limb movement disorder. RLS is a common sleep disorder with a prevalence of 5% to 15% in the general population. RLS can present in childhood, and incidence increases with age. RLS can be idiopathic or secondary to iron deficiency, chronic renal failure, peripheral neuropathy, and medications such as antidepressants (with higher rates for mirtazapine and venlafaxine, while bupropion may reduce symptoms at least in the short term), dopamine antagonists (neuroleptic antipsychotic agents and antinausea medications), and possibly antihistamines. Management includes pharmacologic agents (dopaminergic agents, alpha-2 delta calcium channel ligands, opioids, benzodiazepines) and nonpharmacologic therapies (iron supplementation, behavioral management). Periodic limb movements of sleep are an electrophysiologic finding commonly accompanying RLS. On the other hand, most individuals with periodic limb movements of sleep do not have RLS. The clinical significance of the movements has been argued. Periodic limb movement disorder is a distinct sleep disorder that arises in individuals without RLS and is a diagnosis of exclusion.

The prevalence and associated factors of seasonal exacerbation of subjective symptoms in Japanese patients with restless legs syndrome

OBJECTIVES

To elucidate the prevalence of seasonal exacerbation in patients with restless legs syndrome (RLS) and identify its associated factors.

METHODS

We investigated the presence/absence of seasonal exacerbation of RLS by distributing self-administered questionnaires with an interval of three years. Patients who reported having seasonal exacerbation in both surveys were defined as having seasonal exacerbation. RLS severity was determined using the International Restless Legs Syndrome Rating Scale (IRLS).

RESULTS

Among 180 patients, 89 reported having seasonal exacerbation in the first survey. Among them, only two reported not having seasonal exacerbation in the second survey; thus, 87 (48.3%) patients were considered to have a seasonal exacerbation. Although many of them (68 out of 87, 78.2%) experienced exacerbation in spring or summer, 19 out of 87 (21.8%) reported that their symptoms worsened in fall or winter. All the patients in this study had mild to moderate degrees of RLS severity according to the IRLS score. Multiple logistic regression analyses revealed that having a family history of RLS (p < 0.05) and moderate RLS (p < 0.001) were significantly associated with the presence of seasonal exacerbation.

CONCLUSIONS

This study revealed that approximately half of all RLS patients had seasonal exacerbation of the symptoms and that about 80% of the exacerbation was observed during the spring/summer season. Moreover, seasonal exacerbation is likely to be present even in patients whose symptoms had been improved to moderate severity with pharmacological treatment.

A longitudinal study of restless legs symptoms among patients with depression

BACKGROUND

The aim of this study was to analyse the relationship between depressive symptoms and clinical depression and restless legs symptoms in a longitudinal primary care setting.

METHODS

The prevalence of restless legs symptoms at baseline and after a six-year follow-up was studied in 474 patients with depressive symptoms and 333 population-based control subjects without depressive symptoms. Depressive symptoms at the baseline and after the six-year follow-up were evaluated with the Beck Depression Inventory (BDI) Second Edition. A psychiatric diagnosis was confirmed with a diagnostic interview (M.I.N.I.). Statistical comparisons between groups were made using analysis of variance (ANOVA) for continuous variables and a chi-square test or logistic models for categorical variables. Repeated measures were analysed using generalizing estimating equations (GEE) models.

RESULTS

At baseline the prevalence of restless legs symptoms was 24.3% in control subjects, 43.8% in the patients with depressive symptoms without a depression diagnosis, and 49.3% in clinically depressed patients. During the follow-up up the prevalence of restless legs symptoms declined significantly (p = 0.003). In addition to baseline restless legs symptoms, the prognostic factors for restless legs symptoms among patients with clinical depression were age and BDI score. In the control subjects, moderate and high leisure time physical activity was inversely associated with restless legs symptoms at the follow-up.

CONCLUSIONS

A higher level of baseline depressive symptoms was a risk factor for restless legs symptoms in patients with clinical depression. In the prevention and treatment of restless legs symptoms among the patients with depression, the priority is the effective treatment of depression.

Evaluation of restless leg syndrome symptoms in patients with lumbosacral canal stenosis comparison with normal population

Introduction: Restless leg syndrome (RLS) is a neurological disorder that causes an irresistible urge to move the legs often associated with an unpleasant sensation. Due to some common presentations between RLS and lumbosacral spinal stenosis, the purpose of this study was to evaluate the symptoms of RLS in the presence of spinal stenosis at the same time as normal populations.Materials and methods: This cross-sectional study examined 45 patients with lumbosacral spinal canal stenosis and 45 normal individuals without a specific disease. Patients aged 50-70 years were included in the study. All the statistical analyses were carried out using SPSS 21.0 software and p < 0.05 was considered statistically significant.Results: 19 subjects (42.22%) in the patient group and eight in the normal group (17.8%) suffered from restless leg syndrome. Multiple linear regression analysis revealed that patients with lumbosacral canal stenosis had almost five score less than others in RLS scale.Conclusion: RLS symptoms were more prominent in lumbosacral canal stenosis patients compared to the normal group. The awareness of its symptoms can help reduce misdiagnosis.

Symptom Persistence after Iron Normalization in Women with Restless Legs Syndrome

OBJECTIVE

The aim of this study was to determine the clinical course of restless legs syndrome (RLS) and potential risk factors for the persistence of RLS symptoms after iron normalization in women with RLS and low serum ferritin (<50 μg/L).

METHODS

We reviewed 39 women with RLS and iron deficiency, who achieved iron normalization after oral iron replacement for three months. Risk factors contributing to symptom persistence were estimated by logistic regression analyses. Remission was defined as no RLS symptoms for at least 6 months after the iron normalization.

RESULTS

Over the observation period of 2.5±1.4 years, 15 patients reported no RLS symptom whereas 24 patients still complained of RLS symptoms. The remission rate of RLS with iron replacement was 38.5%. The relative risk of symptom persistence was increased by the duration of RLS symptoms (OR: 1.88, 95% CI: 1.01-3.49) or by the age at RLS diagnosis (OR: 1.25, 95% CI: 1.01-1.56).

CONCLUSION

Almost two-third of RLS patients with iron deficiency showed persistence of the symptom even after iron normalization. Considering that longer duration of RLS symptoms and older age at RLS diagnosis were risk factors for symptom persistence, early intervention of iron deficiency in RLS is warranted.

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.