Epidemiology of restless legs syndrome in Korean adults

Successful treatment of restless legs syndrome accompanied by headaches for 30 years with herbal prescriptions containing Paeoniae Radix: A case report

BACKGROUND

Restless legs syndrome (RLS) is a neurological disorder that causes unpleasant symptoms in the legs when resting, which are relieved by movement. Pharmacotherapy is the standard treatment. However, current treatment provides only symptomatic relief and may result in adverse effects with long-term use. Treatment protocols using herbal medicines have emerged to compensate for this limitation.

CASE PRESENTATION

A 70-year-old Asian woman visited our hospital with worsening headaches that had persisted for 30 years. Her headaches were aggravated by night-time lower-extremity discomfort. The patient was diagnosed with RLS based on the 2012 Revised International Restless Leg Syndrome Study Group Diagnostic Criteria (IRIS). The patient was prescribed herbal medicines, Shihogyeji-tang, Gyejibokryeong-hwan, and Jakyakgamcho-tang, all of which contain Paeoniae Radix. Fourteen days after starting herbal medicine treatment, the IRIS score decreased from 30 to 18. The patient experienced less leg discomfort. Moreover, her sleep time increased, and her headaches resolved. After 28 days of herbal treatment, the IRIS score decreased to 9. Importantly, the patient reported no sleep disturbance or headaches. Subsequently, conventional medications were discontinued. The patient remained stable (IRIS score: 9-10). Herbal treatment was discontinued on day 163. At the last follow-up, (day 364), the patient has not reported any symptom recurrence.

CONCLUSIONS

We described a female patient with a 30-year history of RLS symptoms and related sleep disturbances that induced chronic uncontrolled headaches, who experienced improvements shortly after using herbal medicines containing Paeoniae Radix. Conventional medications were discontinued and the patient had no recurrence of symptoms. Considering these, herbal medicines containing Paeoniae Radix may be a suitable alternative treatment for RLS and its related symptoms.

Restless legs syndrome in patients with obstructive sleep apnea: Association between apnea severity and symptoms of depression, insomnia, and daytime sleepiness

OBJECTIVE

To determine if the prevalence and severity of restless legs syndrome (RLS) varies with apnea severity and analyze differences between the sexes in terms of comorbid RLS with symptoms of depression, insomnia, and daytime sleepiness in patients with obstructive sleep apnea (OSA).

METHODS

Symptoms of depression, insomnia, and daytime sleepiness were defined as Patient Health Questionnaire-9 score ≥10, Insomnia Severity Index score ≥15, and Epworth Sleepiness Scale score ≥11. Multivariate logistic and linear regression analyses were conducted.

RESULTS

In 707 adults with OSA (85.1% males), 16.1% (n = 114) had comorbid RLS. The prevalence of RLS was markedly lower in those with moderate and severe OSA than in those with mild OSA. Similarly, the odds of RLS significantly decreased with increasing apnea-hypopnea index. After controlling for age and sex, in patients with comorbid RLS, the International RLS Study Group Rating Scale scores were negatively correlated with apnea-hypopnea index and a nadir peripheral oxygen saturation during sleep. The presence of RLS was more likely to be associated with symptoms of depression, insomnia, and daytime sleepiness after controlling for confounding variables, but only in men.

CONCLUSIONS

RLS is frequently noted in combination with OSA, with a female preponderance. The severities of OSA and RLS may be negatively associated. In patients with OSA, sex-related differences in terms of comorbid RLS with symptoms of depression, insomnia, and daytime sleepiness warrant further investigations.

Prevalence and clinical correlates of restless legs syndrome in psychiatric patients: A cross-sectional study from North India

Background

Restless legs syndrome (RLS) is a neuro-sensorimotor disorder which is scarcely researched and is commonly missed in routine psychiatry practice.

Aim

To evaluate the prevalence of RLS and its correlates in patients with anxiety, depression, and somatoform disorders.

Methods

A cross-sectional single-center study was undertaken in patients aged 18-65 years suffering from ICD-10 (International Statistical Classification of Diseases-10th edition) diagnosis of anxiety, depressive, and somatoform disorders. RLS was evaluated by using diagnostic criteria of International Restless Legs Syndrome Study Group (IRLSSG) and severity measured on IRLSSG scale. Depression and anxiety were rated on Hamilton Depression and Anxiety Rating Scales respectively, insomnia severity measured by Insomnia Severity Index (ISI), and quality of life measured by WHO Quality of Life-Brief version (WHO-QOL BREF) scale. Serum ferritin levels were measured for evaluating iron deficiency.

Results

The rate of RLS was 66.7%, 50%, and 48% in patients with depressive, anxiety, and somatoform disorders, respectively, with no significant inter-group difference. Nearly one-third of patients suffered from severe to very severe symptoms of RLS, and quality of life was poorest in those with depressive disorders. RLS was significantly higher in females (P = 0.019), who were married (P = 0.040), diagnosed with severe depression (P = 0.029), and abused benzodiazepines (P = 0.045). On binary logistic regression, female gender and presence of clinical insomnia predicted occurrence of RLS.

Conclusion

The prevalence of RLS is very high in patients with common psychiatric disorders which is often missed. Clinical enquiry and examination for reversible causes such as iron deficiency may assist in its diagnosis and improve clinical outcome.

Alterations of the thalamic nuclei volumes and intrinsic thalamic network in patients with restless legs syndrome

We aimed to investigate the alterations of thalamic nuclei volumes and intrinsic thalamic network in patients with primary restless legs syndrome (RLS) compared to healthy controls. Seventy-one patients with primary RLS and 55 healthy controls were recruited. They underwent brain MRI using a three-tesla MRI scanner, including three-dimensional T1-weighted images. The intrinsic thalamic network was determined using graph theoretical analysis. The right and left whole thalamic volumes, and the right pulvinar inferior, left ventral posterolateral, left medial ventral, and left pulvinar inferior nuclei volumes in the patients with RLS were lower than those in healthy controls (0.433 vs. 0.447%, p = 0.034; 0.482 vs. 0.502%, p = 0.016; 0.013 vs. 0.015%, p = 0.031; 0.062 vs. 0.065%, p = 0.035; 0.001 vs. 0.001%, p = 0.034; 0.018 vs. 0.020%, p = 0.043; respectively). There was also a difference in the intrinsic thalamic network between the groups. The assortative coefficient in patients with RLS was higher than that in healthy controls (0.0318 vs. - 0.0358, p = 0.048). We demonstrated the alterations of thalamic nuclei volumes and intrinsic thalamic network in patients with RLS compared to healthy controls. These changes might be related to RLS pathophysiology and suggest the pivotal role of the thalamus in RLS symptoms.

Worldwide estimation of restless legs syndrome: a systematic review and meta-analysis of prevalence in the general adult population

This systematic review, meta-analysis and meta-regression assessed the prevalence of restless legs syndrome (RLS) in the general adult population. Studies identified in Scopus, PubMed, Web of Science, and PsycInfo between January 2000 and February 2022 were included if they used a case-control or cross-sectional design and reported data regarding the prevalence of RLS. The protocol was pre-registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD42022300709). A total of 97 studies including 483,079 participants from 33 different countries met the eligibility criteria. The Newcastle Ottawa Scale was used to evaluate the methodological quality, and the fill-and-trim method was used to correct probable publication bias, while the jack-knife method was performed to assess small study effect. The corrected overall pooled prevalence of RLS was 3% (95% confidence interval [CI] 1.4%-3.8%). The pooled prevalence of RLS syndrome was affected by methodological quality (no data from non-respondents in the included studies), gender (higher among women), study design (lower prevalence in case-control versus cohort and cross-sectional studies). The figures for corrected pooled prevalence among men, women, alcohol consumers and smokers were 2.8% (95% CI 2%-3.7%); 4.7% (95% CI 3.2%-6.3%); 1.4% (95% CI 0%-4.2%); and 2.7% (95% CI 0%-5.3%), respectively. The prevalence among male and female participants was lower in community-based versus non-community-based studies. Moreover, the prevalence was higher in developed versus developing countries and among elders versus adults. In conclusion, RLS is a common disorder in the general adult population, with a higher prevalence in women; however, prevalence data are affected by study design and quality.

Prevalence of restless legs syndrome during the 2019 coronavirus disease pandemic in South Korea: A nationwide cross-sectional population-based study

Background

The 2019 coronavirus disease (COVID-19) pandemic has been associated with a significant increase in sleep disorders. This study aimed to determine the prevalence of restless leg syndrome (RLS) and the effect of COVID-19 on RLS during the pandemic in Korea.

Methods

The National Sleep Survey of South Korea 2022 was employed in this study. This study was a large population-based web survey using a structural questionnaire of a four thousand representative sample of individuals aged 20-69 years in Korea. The survey was conducted between January 2022 and February 2022 during the COVID-19 pandemic. RLS was diagnosed using the Korean version of the paradigm of questions for epidemiological studies of RLS. Chronic persistent RLS was defined for individuals with RLS symptoms at least twice a week.

Results

Six hundred forty-nine (16.2%) and 172 (4.3%) patients were classified as having RLS and chronic persistent RLS, respectively. Female sex, being employed, the presence of COVID-19 vaccine-related adverse events, decreased sleep duration, the presence of EDS, and current treatment for insomnia were significantly associated with chronic persistent RLS.

Conclusion

During the COVID-19 pandemic, the prevalence of RLS and chronic persistent RLS in the adult Korean population was higher than that reported in previous studies.

Restless legs syndrome: Over 50 years of European contribution

Restless legs syndrome (RLS) is a sensorimotor neurological disorder characterised by an urge to move the limbs with a circadian pattern (occurring in the evening/at night), more prominent at rest, and relieved with movements. RLS is one of the most prevalent sleep disorders, occurring in 5%-10% of the European population. Thomas Willis first described RLS clinical cases already in the 17th century, and Karl-Axel Ekbom described the disease as a modern clinical entity in the 20th century. Despite variable severity, RLS can markedly affect sleep (partly through the presence of periodic leg movements) and quality of life, with a relevant socio-economic impact. Thus, its recognition and treatment are essential. However, screening methods present limitations and should be improved. Moreover, available RLS treatment options albeit providing sustained relief to many patients are limited in number. Additionally, the development of augmentation with dopamine agonists represents a major treatment problem. A better understanding of RLS pathomechanisms can bring to light novel treatment possibilities. With emerging new avenues of research in pharmacology, imaging, genetics, and animal models of RLS, this is an interesting and constantly growing field of research. This review will update the reader on the current state of RLS clinical practice and research, with a special focus on the contribution of European researchers.

The prevalence of the restless legs Syndrome/Willis-Ekbom disease among teenagers, its clinical characteristics and impact on everyday functioning

BACKGROUND AND AIMS

The data on the prevalence of the Restless Legs Syndrome/Willis -Ekbom disease (RLS/WED) in the population of teenagers is scarce. The aim of this study was to determine RLS/WED occurrence in adolescents, its diagnostic accuracy, family history, clinical characteristics and impact on everyday functioning.

MATERIAL AND METHODS

A group of 2379 pupils (aged 13-18 y.o.) from 6 randomly selected secondary schools in Gdańsk, Poland were screened for RLS/WED with the use of a questionnaire. In order to verify the diagnosis and perform additional tests (neurological examination, psychological evaluation, biochemical blood tests, demographic questionnaire, International RLS rating scale/IRLSS, Epworth daytime sleepiness scale). all of the respondents with RLS/WED suspicion and their parents were asked for a consultation by a child neurologist. Both children and parents with RLS/WED diagnosis were tested with actigraphy at home for at least two consecutive nights.

RESULTS

Two thousand and ninety seven students (88,15%) filled the questionnaire correctly (1171 girls and 926 boys, 56% and 44%). Sixty four respondents were suspected of having RLS/WED (3,1%), however, 36 of them were diagnosed as RLS/WED-mimics (mainly positional discomfort). Finally, 21 (1%) were diagnosed with definite idiopathic RLS/WED. The average age of symptom onset was 10.96 years. The severity was moderate in the most of the cases (61.9%) and the course of the disease was intermittent in all of them. Family history was positive in 80%. Abnormal actigraphy (PLMS index >5/h) was present in 80%. Blood level of ferritin was low (<50 ng/ml) in 85%. Excessive daytime sleepiness and school problems affected almost half of them. The presence of RLS/WED symptoms was associated with disrupted sleep, behavioral problems (irritability, aggression, hyperactivity), attention deficit and lowered mood. No correlation between RLS/WED and attention deficit hyperactivity disorder (ADHD), nocturnal enuresis or primary headaches was found. Thirty eight percent of the patients sought medical help, but none of them obtained proper diagnosis nor treatment of RLS/WED.

CONCLUSIONS

In this study restless legs syndrome affected 1% of Polish teenagers, in the majority of cases was idiopathic and associated with positive family history. It affected sleep and everyday functioning. Neurological consultation is essential to avoid false positive diagnoses of RLS/WED in teenagers.

Prevalence of Restless Legs Syndrome and its Symptoms among Patients with Spinal Disorders

Restless legs syndrome (RLS) is a neurological disorder that causes uncomfortable sensations in the legs. The purpose of this study was to evaluate the symptoms of RLS in patients with spinal disorders and the impact of RLS on the clinical outcomes of lumbar spinal stenosis (LSS). The records of 278 patients (age range 65–92 years) with spinal disorders who visited our outpatient clinic were reviewed. We used a survey to identify subjects with RLS based on the International RLS Study Group diagnostic criteria. We further recorded patient characteristics, surgical outcomes, sleeping time, mental health condition, and the occurrence of leg cramps. Thirty-two patients (11.5%) met the criteria for RLS. The prevalence of anxiety (46.9% vs. 26.6%, p = 0.023) and leg cramps (90.6% vs. 73.2%, p = 0.030) was higher in patients with RLS than in those without. RLS was present in 12.3% of LSS patients. The visual analog scale score for lower back pain before surgery and at the final follow-up was significantly higher in LSS patients with RLS than in those without. However, the Japanese Orthopaedic Association (JOA) score, JOA score improvement ratio, and VAS score for leg numbness were not significantly different between the groups.

Successful treatment of restless leg syndrome with the traditional herbal medicines Dangguijakyak-san and Shihogyeji-tang: A case report (CARE-compliant)

RATIONALE

Dopamine replacement is currently the standard treatment for restless leg syndrome (RLS); however, various adverse effects are associated with long-term therapy, and the benefits disappear upon discontinuation. To overcome these limitations, interest in traditional East Asian medicine has increased.

PATIENT CONCERNS

A 72-year-old Asian woman originally admitted for an intracerebral hemorrhage presented with complaints of an unpleasant sensation throughout the body that appeared at night.

DIAGNOSES

The patient was diagnosed with chronic persistent RLS based on the 2012 Revised International Restless Leg Syndrome Study Group Diagnostic Criteria.

INTERVENTIONS

The patient was treated with extracts of the traditional herbal medicines Dangguijakyak-san (DS) and Shihogyeji-tang (ST). After 47 days of therapy, all herbal medicines were discontinued, and symptoms had not returned by the last follow-up 244 days after the initial treatment.

OUTCOMES

One week after initiating herbal treatment with DS and ST, the RLS symptoms began to improve, and the total hours of sleep had increased from 2 to 9 hours by day 21, with a Korean version of the international restless legs scale score of 11 points. On day 36, ST was discontinued, given the continued improvement of symptoms. On day 47, symptoms had disappeared (Korean version of the international restless legs scale score: 0), and sleep disturbances caused by RLS had completely resolved. After day 47, DS was also discontinued. There were no adverse effects associated with the administration of DS and ST, and the symptoms had not recurred by the last follow-up on day 244.

LESSONS

In this case, RLS related symptoms, which had been present for approximately 60 years, were improved using only the traditional herbal medicines DS and ST (without dopamine replacement), and no symptoms recurred for 244 days. This case suggests that if replacement therapy is difficult or not desired, herbal medicinal therapies may be an effective alternative. This also suggests that the effect of herbal medicine on RLS might be semi-permanent. Further investigations, including clinical trials, are needed to confirm these effects.

The prevalence and clinical characteristics of restless legs syndrome in patients with iron deficiency anemia in Korea

STUDY OBJECTIVES

While the prevalence and clinical characteristics of restless legs syndrome (RLS) are known to vary according to ethnicity, a detailed evaluation of this condition among patients with iron deficiency anemia (IDA) has not yet been reported in an Asian population. We investigated the prevalence and clinical characteristics of RLS in patients with IDA in Korea compared with age- and sex-matched patients diagnosed with idiopathic RLS.

METHODS

This prospective single-center study was performed at a regional university hospital. Consecutive patients with IDA were enrolled over a 4-year period. Clinical interviews and laboratory tests were conducted at the first visit. RLS diagnosis was confirmed through face-to-face interviews. We randomly selected patients with idiopathic RLS without comorbid medical disorders from our sleep center dataset as control patients. The clinical characteristics of both groups were compared.

RESULTS

We enrolled 124 patients with IDA. Fifty (40.3%) patients were diagnosed with RLS, with 82% exhibiting severe to very severe symptoms. Patients with IDA and RLS were older and reported more sleep deterioration than patients with IDA without RLS. Patients with IDA and RLS also had a more depressed mood and higher periodic limb movement index scores than patients with idiopathic RLS.

CONCLUSIONS

The prevalence of RLS among patients with IDA in Korea was high, with the majority having severe to very severe symptoms. Patients with IDA and RLS had poorer sleep quality and more emotional problems than patients with IDA without RLS. Therefore, patients with IDA should be screened for RLS to prevent adverse effects on the quality of sleep and life.

The seasonal pattern of restless legs syndrome in a sample from the Korean Health Insurance Review and Assessment Service national database

STUDY OBJECTIVES

To assess the seasonality of restless legs syndrome (RLS) using data from the Korean national health insurance database.

METHODS

We retrospectively reviewed a randomly selected sample representing 3% of the national health insurance claims database in South Korea. From this sample, we obtained the monthly numbers of patients with RLS and diagnoses from 2009 to 2016, along with prescriptions for monthly dopamine agonists and clonazepam for patients with RLS from 2009 to 2013. Total dopamine agonist and clonazepam doses were converted to levodopa-equivalent doses, and the monthly cumulative prescription dose was calculated. Cosinor analysis was used to evaluate the seasonal pattern of each variable.

RESULTS

This study included 11,466 patients with RLS and their diagnoses and 4,887 prescriptions for dopamine agonists and clonazepam. There were significant seasonal patterns in the numbers of patients with RLS (P < .001) and diagnoses (P < .001), both of which peaked in August. The magnitude of the greatest difference in the number of patients with RLS between August (highest) and February (lowest) was 29.96% (95% confidence interval, 24.03-100.80), and that of the number of RLS diagnoses was 39.56% (95% confidence interval, 31.24-47.89). The cumulative prescription dose of medication showed no significant seasonality.

CONCLUSIONS

Our findings suggest that the prevalence of RLS is seasonally affected, with an increase during summer.

Is restless legs syndrome in Parkinson disease patients associated with any specific factor?

BACKGROUND

Restless legs syndrome or Willis-Ekbom disease is a disorder characterized by unpleasant sensations associated with the need to mobilize the lower limbs. In Parkinson disease patients, restless legs syndrome is associated with worse quality of life and excessive sleepiness. Regarding other factors, results of different studies are controversial.

OBJECTIVE

To determine the factors associated with the restless legs syndrome presence in Parkinson disease patients.

METHODS

A cross-sectional study was conducted in 88 consecutive Parkinson disease patients from the outpatient clinic for 21 months. Participants underwent a clinical interview, assessment based on standardized scales (Epworth Sleepiness Scale, Parkinson Disease Questionnaire - 39, Pittsburgh Sleep Quality Index, International Restless Legs Syndrome Study Group rating scale), and video-polysomnography.

RESULTS

Out of the 88 participants, 25 had restless legs syndrome. In the multivariate analysis, restless legs syndrome in Parkinson disease has been associated with the symptom of smell loss and quality of sleep and life. In the univariate analysis, restless legs syndrome in Parkinson disease has occurred more frequently in women with higher frequency of insomnia, constipation, and anosmia than in the group without restless legs syndrome.

CONCLUSION

Restless legs syndrome is a prevalent condition in patients with Parkinson disease and is associated with specific characteristics in this group of patients.

Restless Legs Syndrome: Contemporary Diagnosis and Treatment

Restless legs syndrome (RLS) is characterized by an uncomfortable urge to move the legs while at rest, relief upon movement or getting up to walk, and worsened symptom severity at night. RLS may be primary (idiopathic) or secondary to pregnancy or a variety of systemic disorders, especially iron deficiency, and chronic renal insufficiency. Genetic predisposition with a family history is common. The pathogenesis of RLS remains unclear but is likely to involve central nervous system dopaminergic dysfunction, as well as other, undefined contributing mechanisms. Evaluation begins with a thorough history and examination, and iron measures, including ferritin and transferrin saturation, should be checked at presentation and with worsened symptoms, especially when augmentation develops. Augmentation is characterized by more intense symptom severity, earlier symptom occurrence, and often, symptom spread from the legs to the arms or other body regions. Some people with RLS have adequate symptom control with non-pharmacological measures such as massage or temperate baths. First-line management options include iron-replacement therapy in those with evidence for reduced body-iron stores or, alternatively, with prescribed gabapentin or pregabalin, and dopamine agonists such as pramipexole, ropinirole, and rotigotine. Second-line therapies include intravenous iron infusion in those who are intolerant of oral iron and/or those having augmentation with intense, severe RLS symptoms, and opioids including tramadol, oxycodone, and methadone. RLS significantly impacts patients' quality of life and remains a therapeutic area sorely in need of innovation and a further pipeline of new, biologically informed therapies.

Sleep in adults with autism spectrum disorder and attention deficit/hyperactivity disorder: A systematic review and meta-analysis

Sleep-related problems have been frequently reported in neurodevelopmental disorders, with special emphasis in Autism Spectrum Disorder (ASD) and Attention Deficit/Hyperactivity Disorder (ADHD). The aim of the present study is to conduct a systematic review and meta-analysis on sleep disturbances in adults with ASD and/or ADHD (PROSPERO's CRD42019132916). PubMed and PsycINFO were searched for studies reporting data on sleep objective/subjective measures, as well as prevalence data of sleep disorders, in adults with ASD and/or ADHD. A manual search was conducted throughout reference lists of eligible studies. A total of 1126 studies and 66 references were identified by electronic and manual searches, respectively. Of these, 42 studies were included in the meta-analysis. Results showed that both disorders share a similar sleep-impaired profile with higher sleep onset latency, poorer sleep efficiency, greater number of awakenings during sleep, and a general lower self-perceived sleep quality compared with healthy controls. A higher proportion of N1 sleep was found in ASD participants, while a greater Periodic Limb Movements in Sleep is specific in ADHD adults. More studies are needed, especially those directly comparing ASD and ADHD participants. Controlling for medication, intellectual disability, and concurrent psychiatric disorders is mandatory.

Cognitive behavioral therapy for insomnia in restless legs syndrome patients

OBJECTIVES

The purpose of this study was to investigate the effects of cognitive behavioral therapy for insomnia (CBTI) in patients with Restless Legs Syndrome (RLS).

METHODS

This is a randomized controlled study. The patients were sequentially selected and randomly assigned to either a CBTI group or a non-CBTI group. A total of 25 RLS patients with comorbid insomnia were recruited from a tertiary university hospital sleep center. Twelve were assigned to the CBTI group, and 13 were assigned to the non-CBTI group. The CBTI group received 4 sessions of behavioral therapy, while the non-CBTI group received one informative session on sleep hygiene. All patients completed sleep and psychiatric-related questionnaires. In addition, each individual completed a one-week sleep log for collecting subjective sleep data and actigraphy for objective sleep data.

RESULTS

After conducting the CBTI, there were significant improvements in severity of insomnia symptoms, subjective sleep efficiency, total sleep time, latency to sleep onset, wake after sleep onset, objective latency to sleep onset, and anxiety in the CBTI group as compared to the non-CBTI group. The effect of CBTI on sleep-related data was maintained for up to three months.

CONCLUSIONS

CBTI was effective in RLS patients by improving sleep quality and anxiety symptoms. CBTI may be considered in clinical practice for RLS patients with comorbid insomnia.

Inflammatory bowel disease and restless leg syndrome

Objectives:

Inflammatory bowel disease (IBD) has been associated with restless leg syndrome (RLS). This study aims to explore the prevalence, clinical predictors, and severity of RLS in IBD patients compared to controls.

Methods:

We conducted a case-control study between January and December of 2019 comparing IBD patients with controls. Assessment of RLS was performed using the previously validated diagnostic restless leg syndrome questionnaire (RLSQ). Logistic regression analyses were applied to investigate associations between patient demographics and clinical features and RLS diagnosis.

Results:

A total of 218 IBD patients and 211 healthy controls were incorporated after excluding 6 patients with positional discomfort and 4 patients with habitual foot tapping. The mean age was 30.2±11.7 and 64% were females. The prevalence of RLS was 16/218 (7.34%) and 17/211 (8.06%) among cases and controls, respectively. Based on the RLSQ severity score, 6/16 (37.5%), 4/16 (25%) and 1/16 (6.3%) of the IBD patients with RLS had mild, moderate and severe RLS; respectively. The odds of IBD were lower among patients with confirmed RLS (OR=0.90, 95% CI=0.44-1.84, p = 0.78). In the logistic regression analysis, only vitamin B12 deficiency (OR=10.20, 95% CI=1.40-74.10, p = 0.022) was associated with RLS diagnosis among IBD patients.

Conclusion:

No difference was found in the prevalence of RLS between IBD patients and non-IBD controls. Vitamin B12 deficiency was associated with RLS diagnosis among patients with IBD.

Alterations in Salience Network Functional Connectivity in Individuals with Restless Legs Syndrome

BACKGROUND AND PURPOSE

Restless legs syndrome (RLS) is a neurological disorder which is most commonly identified by an urge to move the legs. It often shows alterations in sensory processing which implies the salience network (SN) is experiencing changes. This study investigates the functional connectivity (FC) between the SN and other areas of the brain in RLS patients during the resting state period.

METHODS

Thirty patients with drug naïve idiopathic RLS and 30 healthy age and gender matched controls were included in this study. Resting state fMRIs were performed in the morning during the asymptomatic period. The SN comparisons were conducted between the two groups.

RESULTS

The RLS group showed a reduction in SN FC in the right pyramis, and an increase in SN FC in the bilateral orbitofrontal gyri and right postcentral gyrus.

CONCLUSIONS

The results of this study give reason to believe that SN FC in RLS patients is altered during asymptomatic periods. This could have an influence on the processing of the saliency of information, particularly sensory information processing and inhibition mechanisms.

Association between Restless Legs Syndrome Symptoms and Self-Reported Hypertension: a Nationwide Questionnaire Study in Korea

BACKGROUND

The association between restless legs syndrome (RLS) and hypertension remains controversial. We investigated the relationship between RLS and hypertension in a nationwide sample of the Korean adult population.

METHODS

This was a cross-sectional questionnaire-based study including 2,740 adults aged 19 years or more. Subjects who met the four essential International RLS Study Group criteria and reported symptoms occurring at least once a week were defined as the RLS group. The presence of hypertension was defined as a self-reported history of physician-diagnosed hypertension. We conducted multiple logistic regression analysis to determine the independent association between RLS symptoms and self-reported hypertension after adjusting for potential confounding factors.

RESULTS

Among the 2,740 subjects, 68 (2.5%; 95% confidence interval [CI], 1.9%-3.1%) were found to have RLS with a symptom frequency of at least once a week. The prevalence of self-reported hypertension was 30.9% (95% CI, 20.5%-42.0%) in the RLS group, which was significantly higher than that in controls (12.4%; 95% CI, 11.2%-13.6%; P < 0.001). Multiple logistic regression analysis showed that the adjusted odds ratio for self-reported hypertension in the RLS group was 2.10 (95% CI, 1.12-3.93) compared to controls. In addition to RLS symptoms, old age, being overweight, low education level, diabetes mellitus, and short sleep duration were significantly associated with self-reported hypertension.

CONCLUSION

RLS symptoms occurring at least once a week is independently associated with a higher prevalence of self-reported hypertension in the adult Korean population. Further research will confirm the clinical implication of the present results and the causal relationship between RLS and hypertension.

Restless Legs Syndrome in Parkinson's Disease Patients: Clinical Features Including Motor and Nonmotor Symptoms

Background and Purpose

We investigated the frequency and clinical features of restless legs syndrome (RLS) in patients with Parkinson's disease (PD).

Methods

This study included 74 PD patients. RLS was diagnosed in face-to-face assessments of all of the subjects based on diagnostic criteria of the International Restless Legs Syndrome Study Group revised in 2003. We analyzed the clinical features of PD patients with and without RLS and compared the data to idiopathic RLS.

Results

The frequency of RLS in the cohort was 21.6% (n=16). Two (12.5%) of the patients with RLS were not treated with dopaminergic drugs, while 14 (24.1%) of the 58 patients without RLS received treatment with dopaminergic drugs. Anxiety, depression, and quality of life (QoL) were significantly worst in patients with RLS. PD patients with RLS had significantly worse sleep quality (p=0.003) and worse scores on the cardiovascular subscale of the Scales for Outcomes in Parkinson's Disease for Autonomic Symptoms (p=0.031) compared to those without RLS. In the group of PD patients with RLS, RLS preceding PD onset was related to a lower Hoehn and Yahr stage.

Conclusions

We found that the frequency of RLS in the present patients with PD was higher than that in our previous study of a general population of RLS subjects. Compared to the PD patients without RLS, the present PD patients with RLS suffered from worse sleep quality and QoL, depression, anxiety, and autonomic disturbances, especially those with cardiovascular problems.

Restless legs syndrome in Parkinson's disease and increased cardiovascular risk

ABSTRACT Restless legs syndrome (RLS) is a disorder commonly found in patients with Parkinson's disease, with descriptions for both conditions impairing dopaminergic transmission in central nervous system. Previous studies in varied populations indicate an association between the presence of RLS and increased cardiovascular risk and, so far, there are no consistent studies of this association in Parkinson's disease. Objective: To analyze the influence of RLS on cardiovascular risk in patients with Parkinson's disease. Methods: We reviewed the medical records of 202 patients diagnosed with Parkinson's disease and verified the presence of RLS, cardiovascular comorbidities, blood pressure measurements, lipid profiles and Framingham Risk Scores. Results: Statistically significant higher values of total cholesterol were found for the RLS group (mean 216.6 mg/dL), as well as for LDL cholesterol (mean 145 mg/dL). No statistical difference was found among the other factors. Conclusion: Patients with Parkinson's disease and RLS have a higher prevalence of dyslipidemia than patients without RLS, suggesting a correlation between restless legs and hyperlipidemia. It is questioned whether the dopaminergic substrate is the main factor in the genesis of the syndrome, as even with the use of dopaminergic agonists by both groups, it was possible to observe differences between groups. The hypothesis of the real interference of the syndrome treatment as a protective factor for cardiovascular risk was generated.

The prevalence of restless leg syndrome among pregnant Saudi women

Objectives:

Restless legs syndrome (RLS) is common among pregnant women, but it has not been documented in pregnant Saudi Arabian women. The main purpose of this study was to estimate the extent of the prevalence of RLS and identify both the associated factors and the associated risk factors among pregnant Saudi women.

Methods:

A cross-sectional study was conducted among pregnant women visiting obstetric clinics at King Abdulaziz Medical City in Riyadh (KAMC-Riyadh) over the period from June 1 to November 1, 2014. We interviewed the participants and collected demographic data, number of pregnancies, duration of pregnancy, comorbidities, and symptoms of RLS. The diagnosis of RLS is based on the four criteria designated by the International RLS Study Group.

Results:

The total number of participants enrolled was 517, and the mean age was 30.11 ± 5.42 years. The prevalence of RLS was 21.3% (110/517) (95% confidence interval [CI]: 17.83%-25.06%). RLS symptoms were more common among women in the third trimester (24.1%) compared to the second trimester (14.3%) and first trimester (13.6%), P = 0.043. The stepwise multivariate logistic model identified insomnia (odds ratio [OR]: 3.6, 95% CI: 2.167–6.017, P = 0.001), and poor sleep quality (OR: 4.9, 95% CI: 1.473-16.454, P = 0.010) were associated with RLS.

Conclusion:

RLS occurs in two of ten pregnant women visiting obstetric clinics at KAMC-Riyadh and is strongly associated with insomnia and poor sleep quality. Studies are needed to explore the causality of these associations.

Individuals with Restless Legs Syndrome Tend to have Severe Depressive Symptoms: Findings from a Community-Based Cohort Study

Restless legs syndrome (RLS) is a sensorimotor neurological disturbance causing physical and psychological distress. Here, we investigated the severity and effect of depressive symptoms in RLS among a Korean cohort population. Depressive symptoms were more prevalent in the RLS group than in the non-RLS group [≥mild depression: odds ratio (OR)=1.95, p<0.001; ≥ moderate depression: OR=6.15, p<0.001; and ≥severe depression: OR=56.54, p<0.001], with a predominant proportion of severe depression (97%) in the RLS group. We found that difficulty falling asleep (OR=8.16, p<0.001), broken sleep (OR=11.66, p=0.001), early morning awakening (OR=8.5, p<0.001), and excessive daytime sleepiness (OR=3.04, p=0.031) were significantly frequent in individuals with severe depression in the RLS group. Red blood cell count was significantly low in individuals with severe depression in the RLS group (p=0.041). We found that severe depression was associated with RLS, suggesting the evaluation and management of mood symptoms and sleep-related and hematological features when treating RLS.

Restless legs syndrome and tension-type headache: a population-based study

BACKGROUND

Recent studies have shown a significant association between restless legs syndrome (RLS) and primary headache disorders. Nevertheless, information regarding the association between tension-type headache (TTH) and RLS is limited. This study aimed to investigate the association between RLS and TTH in a population-based sample.

METHODS

We selected a stratified random population sample of Koreans aged 19-69 years and assessed them using a semi-structured interview designed to identify RLS, headache type, and clinical characteristics of TTH. We determined the prevalence and clinical impact of RLS in participants with TTH.

RESULTS

Of the 2695 participants, 570 (21.2%) and 142 (5.3%) were classified as having TTH and RLS, respectively. Among the 570 individuals with TTH, 113 (19.8%) also met the criteria for probable migraine (PM). The prevalence of RLS was significantly higher among individuals with TTH than among those with non-headache (6.0% vs 3.6%, p = 0.018). The prevalence of RLS was significantly higher in subjects with TTH who fulfilled PM criteria than in those with non-headache participants (8.0% vs. 3.6%, p = 0.018). However, RLS prevalence in individuals with TTH who did not fulfil PM criteria did not differ from that of participants with non-headache (5.5% vs. 3.6%, p = 0.063). TTH participants with RLS had higher visual analogue scale scores for headache intensity (5.1 ± 2.0 vs. 4.3 ± 1.8, p = 0.038), and higher prevalence of anxiety (20.6% vs. 8.8%, p = 0.022) and depression (14.7% vs. 3.5%, p = 0.002) than TTH participants without RLS. Multivariable analyses revealed that headache aggravation by movement (odds ratio [OR] = 2.4, 95% confidence interval [CI] = 1.1-5.2) and depression (OR = 3.5, 95% CI = 1.1-11.4) were significant indicators of RLS among individuals with TTH.

CONCLUSIONS

The prevalence of RLS was higher among individuals with TTH than among those with non-headache. Some clinical presentations varied in accordance with the presence of RLS among participants with TTH.

Achievements, challenges, and future perspectives of epidemiologic research in restless legs syndrome (RLS)

In the 20 years since the initial consensus on a common definition for restless legs syndrome (RLS), over 600 scientific reports on epidemiological aspects of RLS have been published. Most are descriptive and address important issues such as prevalence, familial patterns, comorbidities, and quality of life. While the establishment of prospective cohort studies and the use of secondary data sources are rather new to RLS research, both options significantly broaden the possibilities for analysis of disease risk factors. These two options, as well as the inclusion of a broader phenotyping of individual patients, have great potential to elucidate etiologic factors for RLS and expand knowledge about this common disorder. This article summarizes achievements in the area of RLS epidemiology, describes current challenges, and highlights future perspectives in the field.

Default mode network disturbances in restless legs syndrome/Willis-Ekbom disease

BACKGROUND

The unusual sensations of restless legs syndrome/Willis-Ekbom disease (RLS/WED) are induced by rest or a low arousal state with a circadian variation in the threshold for induction. It has been suggested that the emergence of RLS/WED symptoms relates to abnormal brain functions dealing with internally generated stimuli. The purpose of this study was to investigate the changes in the default mode network (DMN) in RLS/WED subjects.

METHODS

Sixteen drug-naïve, idiopathic, RLS/WED subjects, and 16 age-matched and gender-matched healthy subjects were scanned in an asymptomatic resting state. A comparison of the DMN was conducted between the two groups. Resting state functional magnetic resonance imaging (MRI), Korean versions of the International RLS scale, and other sleep questionnaires were used.

RESULTS

The results showed reductions in the DMN connectivity in the left posterior cingulate cortex, the right orbito-frontal gyrus, the left precuneus, and the right subcallosal gyrus of the RLS/WED subjects. The DMN connectivity was increased in sensory-motor-associated circuits, which included the right superior parietal lobule, the right supplementary motor area, and the left thalamus. In addition, the connectivity between the DMN and thalamus was negatively correlated with that in the orbito-frontal gyrus and the subcallosal gyrus in the subjects.

CONCLUSIONS

The results showed disturbances of the DMN in RLS/WED subjects that influence the thalamic relay sensory-motor-associated circuit. These findings may underscore the fact that RLS/WED subjects have disturbances in default mode network functions involving internal stimuli in the resting state. This may be related to compensatory changes to maintain resting.

Increased Risk of Restless Legs Syndrome in Patients With Migraine: A Nationwide Population-Based Cohort Study

Previous studies suggest that an association between restless legs syndrome (RLS) and migraine exists. However, population-based data are unavailable in Asian cohorts. Our study thus aims to evaluate the association between migraine and RLS in a nationwide, population-based cohort in Taiwan and to examine the effects of age, sex, migraine subtype, and comorbidities on RLS development.Data from the Taiwan National Health Insurance Research Database were used. Patients aged 20 years or older with newly diagnosed migraine from 2000 to 2008 were included; 23,641 patients with newly diagnosed migraine and 94,564 subjects without migraine were randomly selected and followed until RLS development, withdrawal from the National Health Insurance, or until the end of 2011. A multivariate Cox proportional hazards regression model was used to explore the risk of RLS in patients with migraine after adjustment for demographic characteristics and comorbidities.Both cohorts were followed for a mean of 7.38 years. After adjustment for covariates, the risk of RLS was 1.42-fold higher (95% confidence interval = 1.13-1.79) in the migraine cohort than in the nonmigraine cohort (7.19 versus 3.42 years per 10,000 person-years). The increased risk was more prominent in males in the migraine cohort (1.87-fold increased risk, 95% confidence interval 1.22-2.85). Neither comorbidity status nor migraine subtype influenced the RLS risk.This population-based study demonstrated that migraine is associated with an increased risk of RLS compared with those without migraine, particularly in male patients with migraine and regardless of the comorbidity status.

Risk of Restless Legs Syndrome Following Tension-Type Headache: A Nationwide Population-Based Cohort Study

Migraine and restless legs syndrome (RLS) appear to be associated, but the relationship between tension-type headache (TTH) and RLS is unknown. This nationwide, population-based, retrospective cohort study explored the potential association between TTH and RLS.We identified 15,504 patients with newly diagnosed TTH from 2000 to 2007 and 62,016 individuals without TTH who were selected by frequency matched based on sex, age, and the index year. The study participants were followed until diagnosed with RLS, withdrawal from the NHI program, or the end of 2011. Cox proportional hazard models were used to identify risk factors for RLS in TTH patients.After adjusting for sex, age, comorbidity, and medications, TTH was significantly associated with an increased risk of RLS (hazard ratio [HR] = 1.57, 95% confidence interval [CI] = 1.22-2.02). The risk was most prominent in patients aged 20 to 39 years in the TTH group, which exhibited a 2.60-fold higher risk (95% confidence interval = 1.53-4.42) of RLS compared with the non-TTH group. The TTH group had a higher risk of RLS than that of the non-TTH group regardless of sex.Tension-type headache appears to be associated with an increased risk of developing RLS. This similarity to migraines may indicate that headache and RLS have a coincident pathophysiological mechanism, a possibility requiring further study. Clinicians should be more attentive to RLS as a possible comorbidity in patients with TTH.

Restless legs syndrome in Egyptian medical students using a validated Arabic version of the Restless Legs Syndrome Rating Scale

OBJECTIVE

Restless legs syndrome (RLS) is a common movement disorder that has a variable prevalence and impact reported from different countries and specific populations. The current study validated an Arabic version of the International Restless Legs Syndrome Study Group (IRLSSG) rating scale (IRLS) and investigated the prevalence and impact of RLS in medical students at Ain Shams University in Cairo.

METHODS

Translation of IRLS was done according to standard recognized guidelines provided by the publisher. A total of 389 medical students (217 female and 172 male) participated in the study and answered four questions to detect RLS as proposed by the IRLSSG. Subjects who answered positively the first three questions were recruited for face-to-face interview to exclude RLS mimics and to answer the IRLS.

RESULTS

A total of 46 subjects (11.8%; 27 female and 19 male) met the four criteria for RLS. Of these, 39 subjects (10%) had idiopathic RLS. Five subjects (1.3%) and two subjects (0.5%) reported association with history of anemia and diabetes mellitus respectively. Their mean total IRLS score was 16.33 ± 5.3, with moderate severity (11.62 ± 3.9) and low impact (3.1 ± 1.8). The prevalence of individuals who had two or more episodes of RLS of at least moderate severity per week was 5.9%.

CONCLUSION

In this specific population of Egyptian medical students, a within-average prevalence of RLS was found with low impact on quality of life similar to worldwide reported populations. RLS sufferers were of high prevalence among this cohort. The Arabic version of IRLS is reliable and valid for further research in Arabic countries.

Migraine and restless legs syndrome are associated in adults under age fifty but not in adults over fifty: a population-based study

BACKGROUND

Recent studies have shown an association between migraine and restless legs syndrome (RLS). However, migraine prevalence peaks from the 20s to 40s whereas RLS prevalence peaks after the 50s. Despite this, reports on how migraine and RLS may be associated by age is limited. Therefore, the purpose of this study is to investigate the comorbidity between migraine and RLS according to age.

METHODS

We selected a stratified random population sample of Koreans aged 19 to 69 years and evaluated them with a 60-item semi-structured interview designed to identify RLS, headache type, and clinical characteristics of migraine. To assess the association between migraine and RLS according to age, we divided participants into 5 age groups (19-29, 30-39, 40-49, 50-59, and 60-69 years) and analysed each group.

RESULTS

Subjects with migraine showed an increased RLS prevalence in the 19-29 (Odds ratio [OR] = 6.6, 95 % confidence interval [CI] = 1.2-36.8) and 40-49 (OR = 6.7, 95 % CI = 1.5-33.5) age groups compared to non-headache controls but failed to showed a significant association in the 50-59 (OR = 1.1, 95 % CI = 0.2-5.6) and 60-69 (OR = 0.4, 95 % CI = 0.1-4.0) age groups. Migraineurs with 1-10 (12.5 %, OR = 2.0, 95 % CI = 1.3-3.2, p = 0.003) and >10 (12.5 %, OR = 2.5, 95 % CI = 1.0-5.6, p = 0.038) attacks per month showed an increased RLS prevalence compared to migraineurs with <1 attack per month (2.1 %). Subjects with non-migraine headaches showed an increased odds for RLS (OR = 1.8, 95 % CI = 1.3-2.7) compared to non-headache controls. There was no significant difference (9.1 % vs. 6.9 %, p = 0.339) in the RLS prevalence between migraineurs and non-migraine headache subjects.

CONCLUSIONS

Our results suggest that migraine and RLS are differently associated according to age.

A comparison of MRI tissue relaxometry and ROI methods used to determine regional brain iron concentrations in restless legs syndrome

Purpose

Magnetic resonance imaging relaxometry studies differed on the relaxometry methods and their approaches to determining the regions of interest (ROIs) in restless legs syndrome (RLS) patients. These differences could account for the variable and inconsistent results found across these studies. The aim of this study was to assess the relationship between the different relaxometry methods and different ROI approaches using each of these methods on a single population of controls and RLS subjects.

Methods

A 3.0-T magnetic resonance imaging with the gradient-echo sampling of free induction decay and echo pulse sequence was used. The regional brain “iron concentrations” were determined using three relaxometry metrics (R2, R2*, and R2′) through two different ROI methods. The substantia nigra (SN) was the primary ROI with red nucleus, caudate, putamen, and globus pallidus as the secondary ROIs.

Results

Thirty-seven RLS patients and 40 controls were enrolled. The iron concentration as determined by R2 did not correlate with either of the other two methods, while R2* and R2′ showed strong correlations, particularly for the substantia nigra and red nucleus. In the fixed-shape ROI method, the RLS group showed a lower iron index compared to the control group in the substantia nigra and several other regions. With the semi-automated ROI method, however, only the red nucleus showed a significant difference between the two groups.

Conclusion

Both the relaxometry and ROI determination methods significantly influenced the outcome of studies that used these methods to estimate regional brain iron concentrations.

Restless Leg Syndrome Across the Globe: Epidemiology of the Restless Legs Syndrome/Willis-Ekbom Disease

There are more than 50 epidemiologic studies measuring the prevalence of restless legs syndrome/Willis-Ekbom disease (RLS/WED) across 5 of the 6 inhabited continents (not Australia), most conducted in North America and Europe. Sufficient studies have been conducted in Asia, North America, and Europe to make inferences on RLS/WED prevalence by region. RLS/WED prevalence is thought to be highest in North America and Europe and lower in Asia. These differences across regions may be explained by cultural, environmental, and genetic factors. Future investigation is needed to determine to what extent these factors affect expression of RLS/WED according to world region.

Brazilian consensus on guidelines for diagnosis and treatment for restless legs syndrome

The Consensus on restless legs syndrome is an effort of neurologists from several Brazilian states, which tirelessly reviewed the literature of recent years in search of evidence, both in regard to diagnosis and treatment, according to the Oxford Centre for Evidence-based Medicine.

Sternberg working memory performance following treatment with pramipexole in patients with moderate-to-severe restless legs syndrome

OBJECTIVES

We recently reported that the P300 amplitude related to the Sternberg working memory (WM) task was significantly lower in drug-naïve severe restless legs syndrome (RLS) patients than controls. Here, we evaluated the effects of pramipexole on the Sternberg WM task performance by event-related potential (ERP) study.

METHODS

Thirteen drug-naïve RLS patients (52.0 ± 9.48 years) were enrolled in the study. Pramipexole was administered over a period of 12 weeks every night 1 h before bedtime. Two ERP studies were carried out: the first was performed just before giving the first dose of pramipexole and the second was conducted at 12-16 weeks after commencement of pramipexole administration. P300 amplitudes and reaction times were compared before and after treatment considering brain regions and memory load as within-subject factors. Clinical and sleep-related variables were correlated with P300 amplitude.

RESULTS

After treatment with pramipexole, the International RLS Severity Scale (IRLS) score was significantly decreased. Sleep quality and depression were also significantly improved. Omission error was significantly reduced without significant change of commission error. Reaction time was significantly shortened, regardless of memory load size, following treatment with pramipexole. Parietal P300 amplitude was significantly increased after treatment with pramipexole for all memory load sizes. Increase of frontal P300 amplitude was significantly correlated with improvement of sleep duration, IRLS, Insomnia Severity Index, and Pittsburgh Sleep Quality Index score.

CONCLUSION

Our study suggested that pramipexole improves WM performance in patients with RLS in addition to improving RLS symptoms, sleep disturbance, and depression.

Daytime sleepiness associated with poor sustained attention in middle and late adulthood

OBJECTIVE

We aimed to determine the association between psychomotor vigilance task (PVT) performance and sleep-related factors including sleep duration, daytime sleepiness, poor sleep quality, insomnia, and habitual snoring in a population-based sample.

METHODS

This was a cross-sectional analysis from the ongoing prospective cohort study, the Korean Genome and Epidemiology Study. We measured PVT performance and documented demographics, sleep-related factors, life style, and medical conditions in community dwelling adults (N = 2499; mean age 57.1 ± 7.3; male 1259). Associations between PVT parameters and sleep-related factors were tested, adjusting for age, gender, smoking, alcohol use, education, body mass index, hypertension, diabetes, depression, and the interval between mid-sleep time and PVT test.

RESULTS

High Epworth Sleepiness Scale (ESS, ≥8) was associated with slower mean reciprocal response speed (mean RRT) (3.69 ± 0.02 vs. 3.77 ± 0.01, p < 0.001), higher probability for increased lapses (≥4) (OR 1.48, CI 1.12-1.88, p = 0.001), and more negative RRT slope (-0.036 ± 0.002 vs. -0.030 ± 0.001, p = 0.02). Older age, female gender, low education level, depressive mood, and the interval between mid-sleep and PVT test were also associated with poor performance. Sleep duration, habitual snoring, insomnia, or poor sleep quality (the Pittsburgh Sleep Quality Index score > 5) was not related to PVT parameters.

CONCLUSIONS

At the population level, our results revealed important modifiers of PVT performance, which included subjective reports of daytime sleepiness.

Gray matter alteration in patients with restless legs syndrome: a voxel-based morphometry study

The purpose of this study was to demonstrate whether or not restless legs syndrome (RLS) is associated with any morphological change in gray matter. Forty-six RLS subjects and 46 controls were enrolled. We performed voxel-based morphometry analysis and compared the results of the two groups. The RLS subjects showed significant regional decreases of gray matter volume in the left hippocampal gyrus, both parietal lobes, medial frontal areas and cerebellum (uncorrected, P<.001). We found that RLS patients showed structural alteration in the brain and alterations in certain parts of the brain in RLS patients are relevant to RLS.

T2 relaxometry using 3.0-tesla magnetic resonance imaging of the brain in early- and late-onset restless legs syndrome

Background and Purpose

Previous T2 relaxometry studies have provided evidence for regional brain iron deficiency in patients with restless legs syndrome (RLS). Measurement of the iron content in several brain regions, and in particular the substantia nigra (SN), in early- and late-onset RLS patients using T2 relaxometry have yielded inconsistent results. In this study the regional iron content was assessed in patients with early- and late-onset RLS using magnetic resonance imaging (MRI), and compared the results with those in controls.

Methods

Thirty-seven patients with idiopathic RLS (20 with early onset and 17 with late onset) and 40 control subjects were studied using a 3.0-tesla MRI with a gradient-echo sampling of free induction decay and echo pulse sequence. The regions of interest in the brain were measured independently by two trained analysts using software known as medical image processing, analysis, and visualization. The results were compared and a correlation analysis was conducted to investigate which brain areas were related to RLS clinical variables.

Results

The iron index in the SN was significantly lower in patients with late-onset RLS than in controls (p=0.034), while in patients with early-onset RLS there was no significant difference. There was no significant correlation between the SN iron index of the late-onset RLS group and clinical variables such as disease severity.

Conclusions

Late-onset RLS is associated with decreased iron content in the SN. This finding supports the hypothesis that regional brain iron deficiency plays a role in the pathophysiology of late-onset RLS.