Prevalence of Restless Legs Syndrome in Migraine Patients: A Case-Control Study. Analysis of Risk Factors for Restless Legs Syndrome in Migraine Patients

Current and emerging pharmaceutical strategies for the treatment and management of restless legs syndrome

INTRODUCTION

Restless legs syndrome (RLS) is a sensory-motor sleep disorder that affects up to 13% of adults in the Western world and 2-4% of children. It impairs night sleep with an impact on daily performances and life quality. Thus, moderate-to-severe RLS requires pharmacological treatment.

AREAS COVERED

In the present review, which is based on PubMed searches with no time limits, the authors discuss the recommended pharmacotherapy for RLS in addition to other emerging treatment options. The authors provide coverage to the current recommendations for both adults and pediatric patients with RLS.

EXPERT OPINION

Current evidence suggests removing all causes of secondary RLS, including iron deficiency, chronic renal failure, drugs, and treating other sleep disorders that may worsen symptoms. Also, intermittent RLS should be addressed with behavioral measures and on-demand therapy. For chronic persistent RLS, α2δ calcium channel ligands are a first-line pharmacological approach, whereas dopamine agonists are associated with increased risk and should be spared. When RLS is refractory to first-line treatment, polytherapy, or opioid monotherapy should be considered. Nonetheless, some patients may not reach sustained symptom relief. Further research is needed to better understand the pathophysiology of RLS and to develop newer more effective drugs.

Sleep Symptoms in Migraine

PURPOSE OF REVIEW

To review replicated and highlight novel studies of sleep in children and adults with episodic and chronic migraine.

RECENT FINDINGS

Attack-related sleep symptoms are most common in the prodrome and may represent early activation of the hypothalamus rather than migraine triggers. Interictally, patients with migraine report poor sleep quality and high rates of insomnia symptoms. Cognitive behavioral therapy for insomnia in adults and adolescents with chronic migraine and comorbid insomnia results in significant improvement on their headache burden. Thus far, objective studies report that migraine per se is a not associated with sleep apnea. At the present time, there is minimal evidence that migraine is under circadian influence. The current body of evidence suggests that the insomnia symptoms and poor sleep quality commonly reported by patients with migraine are not attack-related but occur interictally and are a marker of worsening disease. The development of clinical guidelines to approach sleep symptoms and expansion of CBT-I trials in those with episodic migraine would be clinically valuable.

Sleep Symptoms and Disorders in Episodic Migraine: Assessment and Management

PURPOSE OF REVIEW

We review research on sleep symptoms and disorders in patients with episodic migraine and propose a framework for evaluating sleep symptoms in this patient population.

RECENT FINDINGS

Patients with episodic migraine consistently report poorer sleep on validated self-reports compared to those without migraine. In polysomnographic studies, children with migraine have objectively shorter sleep duration and lower percentage of REM sleep interictally. Prospective actigraphy studies in adults and children suggest that there are no significant changes in sleep duration, efficiency, or quality in the night before or after a migraine attack. The relationship between sleep and migraine is multifaceted. Patients with episodic migraine report poorer sleep and have higher risk of some sleep disorders, including insomnia, sleep-related bruxism, and restless legs syndrome. Sleep screening questions may be incorporated into headache evaluations. Care should be taken to avoid headache medications that may exacerbate sleep symptoms. Evidence-based treatments for insomnia may be initiated while patients await CBT-I. Further studies are needed to assess whether treatment of comorbid sleep disorders results in improvement in migraine-related burden in those with episodic migraine.

Erenumab Impact on Sleep Assessed With Questionnaires and Home-Polysomnography in Patients With Migraine: The ERESON Study

Introduction

Migraine and sleep share a complex and unclear relationship. Poor sleep may trigger migraine attacks; migraine, in turn, is frequently associated with sleep disorders. Few previous studies used questionnaires to assess sleep changes in patients who were treated with migraine-preventive medications (MPMs). More extensive polysomnography (PSG)-based studies for this purpose were not available.

Objective

To investigate possible sleep changes in patients with migraine treated with erenumab, using validated sleep questionnaires and home-PSG.

Methods

This observational, prospective, open-label pilot study was conducted at the Clinical Neurology Unit Headache Center of Udine University Hospital from 2020 to 2021. Patients were treated with erenumab as monotherapy or add-on treatment for migraine prevention. Sleep changes were evaluated with questionnaires and polysomnographic recordings at baseline, after 3 and 12 months of treatment. Erenumab efficacy and safety in migraine prophylaxis were also investigated.

Results

Twenty-nine patients completed 3 months of follow-up, whereas 15 patients completed 12 months. We found a weak trend of improvement in daytime somnolence after 3 months of treatment, with stronger results after 12 months (median Epworth Sleepiness Scale (ESS) score from 6.0 to 4.0, p = 0.015); a significant improvement in subjective sleep quality (median Pittsburgh Sleep Quality Index (PSQI) total score from 7 to 5; p = 0.001) was also observed. Home-PSG showed a significant increase in objective sleep efficiency (SE), both after 3 (from 88.1 to 91.0, p = 0.006) and 12 months (from 87.1 to 91.0, p = 0.006) of treatment. In addition, our data confirmed erenumab effectiveness and safety in migraine prevention.

Conclusion

Our study demonstrated an improvement in both subjective and objective sleep quality in patients treated with a migraine-preventive therapy. Erenumab, in particular, does not cross the blood-brain barrier (BBB), thus a direct effect on sleep is unlikely. Future studies are needed to better understand the mutual influence between migraine and sleep disorders.

Association Between Migraine Complicated With Restless Legs Syndrome and Vitamin D

Background: This study aimed to evaluate the prevalence of restless legs syndrome (RLS) in patients with migraine and explore its association with vitamin D deficiency, aiming to provide biological support for the comorbidity of migraine with RLS, and shed new lights into clinical diagnosis and treatment.

Methods: A case-control study was performed on 175 migraine patients and 151 non-headache controls. The information of all subjects concerning headache severity [visual analog scale (VAS) score], RLS, RLS severity [International Restless Legs Scale (IRLS) score], sleep quality [Pittsburgh sleep quality index (PSQI)], anxiety and depression symptoms [hospital anxiety and depression scale (HADS)], and demographic data were collected. At the same time, serum 25-(OH) D levels were also measured (concentration <20 ng/ml was defined deficiency). Afterward, the logistic regression model was adopted to explore the risk factors for RLS in patients with migraines.

Results: Compared with control group, migraine group had lower vitamin D levels [(21.10 ± 6.58) vs. (16.42 ± 5.6) ng/ml, P < 0.001], a higher rate of vitamin D deficiency (45.03 vs. 72%, P <0001), higher prevalence of RLS (6.62 vs. 22.29%, P < 0.001). Compared with the pure RLS group, RLS with the migraine group had lower vitamin D levels and higher IRLS score (P < 0.05). Compared with pure migraine group, migraine with RLS group had lower vitamin D levels [(17.36 ± 5.56) vs. (13.15 ± 4.42) ng/ml, P < 0.001], higher incidence of vitamin D deficiency (66.18 vs. 92.31%, P = 0.001), higher frequency of headache attacks (P = 0.004). Thereafter, the multivariate logistic regression model was employed to adjust confounding factors such as age, gender, season, frequency of headache attacks, PSQI score, and HADS scores. According to the results vitamin D deficiency in patients with migraines was an independent risk factor for RLS (OR = 5.03, 95%CI: 1.2–21.16, P = 0.027).

Conclusions: The prevalence of RLS in migraine patients was significantly higher than that in the non-headache population. Besides, vitamin D levels decreased, while the incidence of vitamin D deficiency increased in the migraine patients complicated with RLS. Finally, the occurrence of RLS in migraine patients was significantly related to vitamin D deficiency.

Pathophysiological Bases of Comorbidity in Migraine

Despite that it is commonly accepted that migraine is a disorder of the nervous system with a prominent genetic basis, it is comorbid with a plethora of medical conditions. Several studies have found bidirectional comorbidity between migraine and different disorders including neurological, psychiatric, cardio- and cerebrovascular, gastrointestinal, metaboloendocrine, and immunological conditions. Each of these has its own genetic load and shares some common characteristics with migraine. The bidirectional mechanisms that are likely to underlie this extensive comorbidity between migraine and other diseases are manifold. Comorbid pathologies can induce and promote thalamocortical network dysexcitability, multi-organ transient or persistent pro-inflammatory state, and disproportionate energetic needs in a variable combination, which in turn may be causative mechanisms of the activation of an ample defensive system with includes the trigeminovascular system in conjunction with the neuroendocrine hypothalamic system. This strategy is designed to maintain brain homeostasis by regulating homeostatic needs, such as normal subcortico-cortical excitability, energy balance, osmoregulation, and emotional response. In this light, the treatment of migraine should always involves a multidisciplinary approach, aimed at identifying and, if necessary, eliminating possible risk and comorbidity factors.

Cerebrovascular Risk in Restless Legs Syndrome: Intima-Media Thickness and Cerebral Vasomotor Reactivity: A Case-Control Study

PURPOSE

Although some studies have suggested an association between cardiovascular disease and restless legs syndrome (RLS), the mechanisms underlying this relationship remain unclear. The intima-media thickness (IMT) and vasomotor reactivity are two simple, non-invasive tools to investigate preclinical atherosclerosis and microangiopathy, respectively. The aims of this study were to evaluate carotid IMT and to explore vasomotor reactivity in idiopathic RLS (iRLS) patients.

PATIENTS AND METHODS

We enrolled 44 iRLS after exclusion of patients with secondary causes of RLS, history of vascular events, known uncontrolled vascular risk factors and other neurological disorders. Forty-four age and sex matched controls were therefore recruited. No significant differences in demographic data and vascular risk factors were found between the two groups. Carotid IMT was measured with a high-resolution B-mode ultrasound on the far-wall of common carotid artery, 10 mm and 30 mm to the carotid bulb. Vasomotor reactivity to hypo- and hypercapnia was assessed, by right middle cerebral artery transcranial Doppler, accordingly to the changes in peak systolic velocity, peak diastolic velocity and mean blood flow velocity.

RESULTS

Mean IMT was significantly increased in patients with iRLS when measured immediately proximally to carotid bifurcation (0.73; sd=0.17), versus controls (0.65; sd=0.13); p=0.035. Patients showed higher cerebrovascular flow velocities (CBFVs) compared to controls. After multivariate analysis, age, hypertension and iRLS proved to be independent IMT predictors.

CONCLUSION

Increased IMT and higher CBFVs in iRLS support the association of iRLS with vascular damage, possibly through enhanced atherogenesis and sympathetic hyperactivity. However, to clarify a causal relationship, further longitudinal assessment of these parameters is needed, trying to control all their physiological modifying factors.

Migraine and sleep disorders: a systematic review

Migraine and sleep disorders are common and often burdensome chronic conditions with a high prevalence in the general population, and with considerable socio-economic impact and costs.The existence of a relationship between migraine and sleep disorders has been recognized from centuries by clinicians and epidemiological studies. Nevertheless, the exact nature of this association, the underlying mechanisms and interactions are complex and not completely understood. Recent biochemical and functional imaging studies identified central nervous system structures and neurotransmitters involved in the pathophysiology of migraine and also important for the regulation of normal sleep architecture, suggesting a possible causative role, in the pathogenesis of both disorders, of a dysregulation in these common nervous system pathways.This systematic review summarizes the existing data on migraine and sleep disorders with the aim to evaluate the existence of a causal relationship and to assess the presence of influencing factors. The identification of specific sleep disorders associated with migraine should induce clinicians to systematically assess their presence in migraine patients and to adopt combined treatment strategies.

Clinical presentation, diagnosis and polysomnographic findings in children with migraine referred to sleep clinics

OBJECTIVE

An association between migraine and sleep disturbances in children was reported, yet limited clinical data exist. The current study addresses the clinical presentation, polysomnographic (PSG) characteristics, and comorbid sleep diagnoses of children with migraine referred to the sleep clinic.

PATIENTS

A retrospective review was performed of headache center patients evaluated by the sleep center between 2007 and 2017. Children ≤18 years old, diagnosed with migraine headache, and who had PSG within one year of evaluation in the headache clinic, were included. PSG findings, as well as demographics, were compared to a group of controls aged 5-14 years-old.

RESULTS

In sum, 185 children with a diagnosis of migraine were included: 39% males, 75% Caucasian, mean age 13.5 ± 3.4, and 57% obese. Additionally, 180 children were included in the control group. The common presenting sleep symptoms were snoring (66%), sleep onset and sleep maintenance problems (25%), and excessive daytime sleepiness (20%). For the sleep diagnosis, 40% had obstructive sleep apnea (OSA), 27% had insomnia, 15% had periodic limb movement disorder (PLMD), and 6% had a central disorder of hypersomnolence. In terms of sleep architecture, children with migraine had significantly higher NREM 2 (p < 0.001) and a lower percentage of NREM3 (p < 0.001) compared to controls after adjustment for demographics and the presence of sleep-disordered breathing.

CONCLUSIONS

Children referred to the sleep clinic who also had migraine, experience various types of sleep complaints. OSA, insomnia, and PLMD were relatively common in this population. Changes in sleep architecture, specifically increased NREM2 and decreased slow wave sleep compared to the control group, were also observed.

The association between migraine and restless legs syndrome: an updated systematic review and meta-analysis

OBJECTIVE

This study aims to gain further insight into the association between migraine and restless legs syndrome (RLS).

METHODS

A literature search of PubMed, Embase, and Web of Science was performed for studies investigating the association between any migraine and RLS; a meta-analysis of eligible studies was conducted to determine a pooled effect estimate for the association.

RESULTS

Fifteen studies were included in this meta-analysis. The studies differed in methodology, but all investigated the association between migraine and RLS. Pooled RLS prevalence was 17.0% [95% confidence interval (CI) 15.0%-20.0%] among migraineurs, and 7.0% (95% CI 5.0%-8.0%) among no migraine individuals. Pooled analyses showed that migraine was associated with RLS, but effect estimates were substantially higher in case-control studies [pooled odds ratio (OR) = 3.77, 95% CI 2.73-5.21; I² = 50.1%] than in cross-sectional studies (pooled OR = 1.25, 95% CI 1.11-1.41; I² = 34.2%). Subgroup analyses were not conducted to find potential factors that affect this association because of too few available studies.

CONCLUSIONS

This updated meta-analysis confirms the association between migraine and RLS. Future studies should specifically investigate the potential effects of gender, age, aura status, and type (episodic or chronic) of migraine on the association between the two disorders.

Restless legs syndrome is associated with headache-related disabilities in patients with migraine: a prospective 7-year follow-up study

BACKGROUND AND PURPOSE

No prospective study has evaluated the impact of restless legs syndrome (RLS) on clinical factors in patients with migraine. We planned a prospective study to assess the impact of RLS comorbid status on clinical factors in patients with migraine.

METHODS

A total of 101 patients with migraine who were evaluated for RLS twice at 7-year intervals in a university hospital setting were included in this study. The RLS group was defined as positive for RLS at either baseline or follow-up and the non-RLS group was defined as negative for RLS at both baseline and follow-up. The Migraine Disability Assessment (MIDAS) questionnaire, Beck Depression Inventory-II (BDI-II), Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale were administered to all patients.

RESULTS

The RLS prevalence was 16.8% at baseline and 20.8% at follow-up. Compared with the non-RLS group (n = 27), the RLS group (n = 74) showed a significantly higher rate of smoking and higher MIDAS and BDI-II scores at 7-year follow-up. A significant reduction in MIDAS and BDI-II scores at 7-year follow-up compared with those at baseline was observed in the non-RLS group, but not in the RLS group. The non-RLS group showed a significantly lower MIDAS score at 7-year follow-up than the RLS group after adjusting for confounding variables such as age, gender, smoking status, Epworth Sleepiness Scale and PSQI scores using analysis of covariance. The persistent RLS group (n = 11) (positive for RLS at both baseline and follow-up) showed a significantly higher rate of smoking and increased MIDAS, BDI-II and PSQI scores compared with the non-RLS group (n = 74) at 7-year follow-up.

CONCLUSION

Our prospective study showed that RLS had a significant impact on headache-related disability in patients with migraine.

Prevalence of restless legs syndrome in individuals with migraine: a systematic review and meta-analysis of observational studies

OBJECTIVE

Recent studies have shown an association between migraine and restless legs syndrome (RLS), but RLS prevalence among individuals with migraine differs substantially across studies. The present work aimed to comprehensively assess available evidence to estimate RLS prevalence among individuals with migraine and non-migraine controls.

METHOD

Web of Science, PubMed, Embase, Chinese National Knowledge Infrastructure, Wanfang, and SinoMed databases were searched for observational and case-control studies of RLS prevalence among individuals with migraine. Eligible studies were meta-analyzed using Stata 12.0 software.

RESULTS

Pooled RLS prevalence in migraine was 19%, and the prevalence was lower in Asia (16%) than outside Asia (21%). Pooled RLS prevalence was 18.8% among individuals with migraine with aura, and 18.5% among individuals with migraine without aura; the RLS prevalence in migraine with aura (MA) was higher than that of migraine without aura (MO) (OR 1.17, 95%CI 1.01-1.34; p = 0.037). Pooled RLS prevalence in a case-control study was significantly higher among individuals with migraine (17.9%) than among non-migraine controls (7.1%) (OR 2.65, 95%CI 2.26-3.10; p < 0.001).

CONCLUSION

Our meta-analysis provides the first reliable pooled estimate of RLS prevalence among individuals with migraine, and it provides strong evidence that RLS risk is higher among individuals with migraine than among controls.

Non-headache symptoms in migraine patients

Migraine is one of the most common neurological disorders. In addition to severe headaches, non-headache symptoms associated with migraine attacks as well as co-morbid disorders frequently aggravate the disabling of migraine patients. Some of these symptoms are related to poor outcomes. In this review, we update the advances of studies on certain non-headache symptoms, including visual disturbance, gastrointestinal symptoms, allodynia, vestibular symptoms, and symptoms of co-morbid restless legs syndrome and psychiatric disorders.