Clinical Efficacy and Safety of Intravenous Ferric Carboxymaltose for Treatment of Restless Legs Syndrome: A Multicenter, Randomized, Placebo-controlled Clinical Trial.

STUDY OBJECTIVES: Iron therapy is associated with improvements in restless legs syndrome (RLS). This multicenter, randomized, double-blind study evaluated the effect of intravenous ferric carboxymaltose (FCM) on RLS. METHODS: A total of 209 adult patients with a baseline International Restless Legs Syndrome (IRLS) score ≥15 were randomized (1:1) to FCM (750 mg/15 mL) or placebo on study Days 0 and 5. Ongoing RLS medication was tapered starting on Day 5, with the goal of discontinuing treatment or achieving the lowest effective dose. Co-primary efficacy endpoints were change from baseline in IRLS total score and the proportion of patients rated as much/very much improved on the Clinical Global Impression-investigator (CGI-I) scale at Day 42 in the "As-Treated" population. RESULTS: The "As-Treated" population comprised 107 FCM and 101 placebo recipients; 88 (82.2%) and 68 (67.3%), respectively, completed the Day 42 assessment. The IRLS score reduction was significantly greater with FCM versus placebo: least-squares mean (95% confidence interval [CI]) -8.0 (-9.5, -6.4) versus -4.8 (-6.4, -3.1); P = 0.0036. No significant difference was observed in the proportion of FCM (35.5%) and placebo (28.7%) recipients with a CGI-I response (odds ratio 1.37 [95% CI: 0.76, 2.47]; P = 0.2987). Fewer patients treated with FCM (32.7%) than placebo (59.4%) received RLS interventions between Day 5 and study end (P = 0.0002). FCM was well tolerated. CONCLUSION: The IRLS score improved with intravenous FCM versus placebo, although the combination of both co-primary endpoints was not met. Potential methodological problems in the study design are discussed.

The Role of Circadian Rhythms and Sleep in Anorexia Nervosa.

Importance: Observational studies have associated anorexia nervosa with circadian rhythms and sleep traits. However, the direction of causality and the extent of confounding by psychosocial comorbidities in these associations are unknown. Objectives: To investigate the association between anorexia nervosa and circadian and sleep traits through mendelian randomization and to test the associations between a polygenic risk score (PRS) for anorexia nervosa and sleep disorders in a clinical biobank. Design, Setting, and Participants: This genetic association study used bidirectional 2-sample mendelian randomization with summary-level genetic associations between anorexia nervosa (from the Psychiatric Genomics Consortium) and chronotype and sleep traits (primarily from the UK Biobank). The inverse-variance weighted method, in addition to other sensitivity approaches, was used. From the clinical Mass General Brigham (MGB) Biobank (n = 47 082), a PRS for anorexia nervosa was calculated for each patient and associations were tested with prevalent sleep disorders derived from electronic health records. Patients were of European ancestry. All analyses were performed between February and August 2023. Exposures: Genetic instruments for anorexia nervosa, chronotype, daytime napping, daytime sleepiness, insomnia, and sleep duration. Main Outcomes and Measures: Chronotype, sleep traits, risk of anorexia nervosa, and sleep disorders derived from a clinical biobank. Results: The anorexia nervosa genome-wide association study included 16 992 cases (87.7%-97.4% female) and 55 525 controls (49.6%-63.4% female). Genetic liability for anorexia nervosa was associated with a more morning chronotype (ß = 0.039; 95% CI, 0.006-0.072), and conversely, genetic liability for morning chronotype was associated with increased risk of anorexia nervosa (ß = 0.178; 95% CI, 0.042-0.315). Associations were robust in sensitivity and secondary analyses. Genetic liability for insomnia was associated with increased risk of anorexia nervosa (ß = 0.369; 95% CI, 0.073-0.666); however, sensitivity analyses indicated bias due to horizontal pleiotropy. The MGB Biobank analysis included 47 082 participants with a mean (SD) age of 60.4 (17.0) years and 25 318 (53.8%) were female. A PRS for anorexia nervosa was associated with organic or persistent insomnia in the MGB Biobank (odds ratio, 1.10; 95% CI, 1.03-1.17). No associations were evident for anorexia nervosa with other sleep traits. Conclusions and Relevance: The results of this study suggest that in contrast to other metabo-psychiatric diseases, anorexia nervosa is a morningness eating disorder and further corroborate findings implicating insomnia in anorexia nervosa. Future studies in diverse populations and with subtypes of anorexia nervosa are warranted.

Restless legs syndrome, neuroleptic-induced akathisia, and opioid-withdrawal restlessness: shared neuronal mechanisms?

Restlessness is a core symptom underlying restless legs syndrome (RLS), neuroleptic-induced akathisia, and opioid withdrawal. These three conditions also share other clinical components suggesting some overlap in their pathophysiology. Recent prospective studies demonstrate the frequent incidence of RLS-like symptoms during opioid withdrawal and supervised prescription opioid tapering. Based on the therapeutic role of µ-opioid receptor (MOR) agonists in the three clinical conditions and recent preclinical experimental data in rodents, we provide a coherent and unifying neurobiological basis for the restlessness observed in these three clinical syndromes and propose a heuristic hypothesis of a key role of the specific striatal neurons that express MORs in akathisia/restlessness.

Lack of Efficacy of Suvorexant in People with Insomnia and Poorly Controlled Type 2 Diabetes.

Objective/Background: Sleep disturbance is a common and underappreciated feature of diabetes and sleep may contribute to glycemic control in people with type 2 diabetes (T2D). We conducted a 3-month trial to examine the efficacy of suvorexant in improving sleep and health outcomes in people with suboptimally controlled T2D and insomnia. Participants/Methods: This parallel, double-blind, randomized placebo-controlled trial was conducted using the sequential parallel comparison design (SPCD). Sixty-nine people with poorly controlled T2D (HbA1c ≥ 6.5) were randomized to placebo and/or suvorexant (10-20 mg). The primary outcome was subjective total sleep time (sTST), and secondary outcomes were Insomnia Severity Index (ISI) score and wake time after sleep onset (WASO). Exploratory outcomes included sleep efficiency, hemoglobin A1c (HbA1c), and C-reactive protein (CRP). Exploratory analyses were conducted on relationships between sleep and diabetes outcomes. Results: There were no significant improvements in sTST (p = 0.27), ISI (p = 0.86), or WASO (p = 0.94) among participants taking suvorexant compared to placebo. There were also no significant changes in any of the exploratory endpoints. Improvements in sleep were associated with improvements in both objective (ie, HbA1c) and subjective (ie, Diabetes Distress Scale) measures of diabetes, as well as reductions in depressive symptoms, independent of treatment assignment. Conclusion: The study did not find evidence that suvorexant is efficacious for insomnia in people with poorly controlled T2D. The associations of improved sleep with improvements in both diabetes-related metrics and depressive symptoms across groups highlight the importance of identifying and treating sleeping difficulties in this population. CT Registration #: Nct03818581.

Prevalence of Current Restless Legs Syndrome Symptoms Among Patients Treated with Buprenorphine/Naloxone for Opioid Use Disorder.

Objective: The purpose of this study was to determine the prevalence of Restless Legs Syndrome (RLS) in patients with Opioid Use Disorder (OUD) taking buprenorphine/naloxone maintenance therapy, and to assess symptom frequency, severity, and sleep disruption due to RLS. Methods: Surveys inquired about demographic information, amount of time on maintenance treatment, previous drug use, current prescribed medications and alcohol use, and RLS symptoms. Participants were determined to have definite, probable, possible, or no RLS symptoms based on pre-established criteria from the Cambridge-Hopkins Questionnaire. Results: The sample (n=129) was 33.3% female, 81.5% white, and the mean age was 40.6 years (SD=11.9). The median duration of buprenorphine/naloxone use was 3 years. 13.2% of participants had definite/probable RLS symptoms; these symptoms tended to be of moderate severity, occur at least 5-15 times a month, and disrupt sleep to a moderate degree. Of the 17 participants with definite/probable RLS symptoms, just four were taking a medication commonly used to alleviate RLS. An additional 7.0% had possible RLS symptoms. Conclusion: Relatively high rates of current RLS symptoms were observed; the prevalence of clinically significant RLS was notably higher than that seen in the general population or in previously assessed clinical populations. RLS is common in those acutely withdrawing from opioids, and our data demonstrate that these symptoms are present in a sizable portion of patients on OUD maintenance therapy. Most patients with definite/probable current RLS symptoms did not report taking prescribed medications that have established efficacy for RLS.

A Novel Home-Based Study of Circadian Rhythms: Design, Rationale, and Methods for the Circadia Study.

The Circadia Study (Circadia) is a novel "direct-to-participant" research study investigating the genetics of circadian rhythm disorders of advanced and delayed sleep phase and non-24 hour rhythms. The goals of the Circadia Study are twofold: (i) to create an easy-to-use toolkit for at-home circadian phase assessment for patients with circadian rhythm disorders through the use of novel in-home based surveys, tests, and collection kits; and (ii) create a richly phenotyped patient resource for genetic studies that will lead to new genetic loci associated with circadian rhythm disorders revealing possible loci of interest to target in the development of therapeutics for circadian rhythm disorders. Through these goals, we aim to broaden our understanding and elucidate the genetics of circadian rhythm disorders across a diverse patient population while increasing accessibility to circadian rhythm disorder diagnostics reducing health disparities through self-directed at-home dim light melatonin onset (DLMO) collections.

Efficacy and safety of tonic motor activation (TOMAC) for medication-refractory restless legs syndrome: a randomized clinical trial.

STUDY OBJECTIVES: The purpose of this study was to evaluate the efficacy and safety/tolerability of bilateral high-frequency tonic motor activation (TOMAC) in patients with medication-refractory restless legs syndrome (RLS). METHODS: RESTFUL was a multicenter, randomized, double-blind, sham-controlled trial in adults with medication-refractory moderate-to-severe primary RLS. Participants were randomized 1:1 to active or sham TOMAC for a double-blind, 4-week stage 1 and all received active TOMAC during open-label, 4-week stage 2. The primary endpoint was the Clinical Global Impressions-Improvement (CGI-I) responder rate at the end of stage 1. Key secondary endpoints included change to International RLS Study Group (IRLS) total score from study entry to the end of stage 1. RESULTS: A total of 133 participants were enrolled. CGI-I responder rate at the end of stage 1 was significantly greater for the active versus sham group (45% vs. 16%; Difference = 28%; 95% CI 14% to 43%; p = .00011). At the end of stage 2, CGI-I responder rate further increased to 61% for the active group. IRLS change at the end of stage 1 improved for the active versus sham group (-7.2 vs. -3.8; difference = -3.4; 95% CI -1.4 to -5.4; p = .00093). There were no severe or serious device-related adverse events (AEs). The most common AEs were mild discomfort and mild administration site irritation which resolved rapidly and reduced in prevalence over time. CONCLUSIONS: TOMAC was safe, well tolerated, and reduced symptoms of RLS in medication-refractory patients. TOMAC is a promising new treatment for this population. CLINICAL TRIAL: Noninvasive Peripheral Nerve Stimulation for Medication-Refractory Primary RLS (The RESTFUL Study); clinicaltrials.gov/ct2/show/NCT04874155; Registered at ClinicalTrials.gov with the identifier number NCT04874155.

Do Insomnia Treatments Improve Daytime Function?

A scientific advisory panel of seven U.S. and Canadian sleep experts performed a clinical appraisal by comparing general medical opinion, assessed via a survey of practicing clinicians, regarding insomnia treatment, with the available scientific evidence. This clinical appraisal focuses on the specific statement, "Treatments for insomnia have uniformly been shown to significantly improve the associated daytime impairment seen with insomnia." The advisory panel reviewed and discussed the available body of evidence within the published medical literature to determine what discrepancies may exist between the currently published evidence base and general medical opinion. The advisory panels' evaluation of this statement was also compared with the results of a national survey of primary care physicians, psychiatrists, nurse practitioners, physician assistants, and sleep specialists in the United States. Contrary to general medical opinion, the expert advisory panel concluded that the medical literature did not support the statement. This gap highlights the need to educate the general medical community regarding insomnia treatment efficacy in pursuit of improved treatment outcomes.

Disrupted white matter integrity in primary insomnia and major depressive disorder: relationships to sleep quality and depression severity.

This study examined the integrity of white matter tracts in 25 participants with primary insomnia (PI), 50 participants with major depressive disorder (MDD), and 25 healthy controls. Seven white matter tracts, selected based on prior research, were quantified by fractional anisotropy (FA) as well as by related measures of diffusivity using diffusion tensor imaging (DTI) on a 3-T scanner. All 100 participants were free of significant medical, psychiatric (excluding the MDD group) and sleep disorders (excluding the PI group), were free of central nervous system medications, and completed an extensive clinical assessment. Subjective and objective sleep measures revealed significant sleep disruption in both the PI and MDD groups. Relative to the controls, both the PI and MDD groups demonstrated impaired integrity in three of the seven white matter tracts: the genu of the corpus callosum (GenuCC), the superior longitudinal fasciculus (SLF), and the inferior longitudinal fasciculus (ILF). We demonstrated reduced FA in the GenuCC, reduced FA and reduced axial diffusivity (AD) in the SLF, as well as reduced AD and radial diffusivity in the ILF. Finally, in an exploratory analysis of the combined cohorts, FA in the GenuCC and FA in the SLF were negatively correlated with depression severity and positively correlated with total sleep time. Abnormalities documented in the GenuCC, SLF and ILF, and present in both the PI and MDD groups may suggest some shared neurobiology.

Should Trazodone Be First-Line Therapy for Insomnia? A Clinical Suitability Appraisal.

Trazodone is one of the most commonly used prescription medications for insomnia; however, some recent clinical guidelines do not recommend its use for treating insomnia. This clinical appraisal critically reviews the scientific literature on trazodone as a first-line treatment for insomnia, with the focus statement "Trazodone should never be used as a first-line medication for insomnia." In addition, field surveys were sent to practicing physicians, psychiatrists, and sleep specialists to assess general support for this statement. Subsequently, a meeting with a seven-member panel of key opinion leaders was held to discuss published evidence in support and against the statement. This paper reports on the evidence review, the panel discussion, and the panel's and healthcare professionals' ratings of the statement's acceptability. While the majority of field survey responders disagreed with the statement, the majority of panel members agreed with the statement based on the limited published evidence supporting trazodone as a first-line agent as they understood the term "first-line agent".

What Should Be the Focus of Treatment When Insomnia Disorder Is Comorbid with Depression or Anxiety Disorder?

Insomnia is a significant, highly prevalent, persistent public health problem but often remains undiagnosed and untreated. Current treatment practices are not always evidence-based. When insomnia is comorbid with anxiety or depression, treatment often targets that comorbid condition with the expectation that improvement of the mental health condition will generalize to sleep symptoms. An expert panel of seven members conducted a clinical appraisal of the literature regarding the treatment of insomnia when comorbid anxiety or depression are also present. The clinical appraisal consisted of the review, presentation, and assessment of current published evidence as it relates to the panel's predetermined clinical focus statement, "Whenever chronic insomnia is associated with another condition, such as anxiety or depression, that psychiatric condition should be the only focus of treatment as the insomnia is most likely a symptom of the condition". The results from an electronic national survey of US-based practicing physicians, psychiatrists, and sleep (N = 508) revealed that >40% of physicians agree "at least somewhat" that treatment of comorbid insomnia should focus solely on the psychiatric condition. Whereas 100% of the expert panel disagreed with the statement. Thus, an important gap exists between current clinical practices and evidence-based guidelines and more awareness is needed so that insomnia is treated distinctly from comorbid anxiety and depression.

Long-Term Use of Insomnia Medications: An Appraisal of the Current Clinical and Scientific Evidence.

While evidence supports the benefits of medications for the treatment of chronic insomnia, there is ongoing debate regarding their appropriate duration of use. A panel of sleep experts conducted a clinical appraisal regarding the use of insomnia medications, as it relates to the evidence supporting the focus statement, "No insomnia medication should be used on a daily basis for durations longer than 3 weeks at a time". The panelists' assessment was also compared to findings from a national survey of practicing physicians, psychiatrists, and sleep specialists. Survey respondents revealed a wide range of opinions regarding the appropriateness of using the US Food and Drug Administration (FDA)-approved medications for the treatment of insomnia lasting more than 3 weeks. After discussion of the literature, the panel unanimously agreed that some classes of insomnia medications, such as non-benzodiazepines hypnotics, have been shown to be effective and safe for long-term use in the appropriate clinical setting. For eszopiclone, doxepin, ramelteon and the newer class of dual orexin receptor antagonists, the FDA label does not specify that their use should be of a limited duration. Thus, an evaluation of evidence supporting the long-term safety and efficacy of newer non-benzodiazepine hypnotics is timely and should be considered in practice recommendations for the duration of pharmacologic treatment of chronic insomnia.

Randomized, crossover, open-label study of the relative bioavailability and safety of FT218, a once-nightly sodium oxybate formulation: Phase 1 study in healthy volunteers.

OBJECTIVES: Treatment for narcolepsy with sodium oxybate (SXB) has required twice-nightly dosing, at bedtime and 2.5-4 h later. This study evaluated the pharmacokinetics of FT218, an investigational, extended-release, once-nightly formulation of SXB (ON-SXB), vs twice-nightly SXB. METHODS: In this phase 1, open-label study, healthy volunteers were randomized (1:1) to ON-SXB 6 g or twice-nightly SXB (two 3-g doses administered 4 h apart); minimum 3-day washout before crossover. Doses were administered 2 h post-evening meal. Blood samples for pharmacokinetic assessments were collected predose and up to 14 h after the first dose during each treatment period. RESULTS: Twenty-eight participants were enrolled (mean age, 39.6 years; 54% women; 93% white). Mean ± SEM area under the concentration-time curve for ON-SXB was 282.7 ± 30.2  µg·h/mL vs 273.3 ± 27.8 µg·h/mL for twice-nightly SXB. Geometric mean ratio (GMR; 90% CI) was 102.9 (98.0-108.0). Maximum γ-hydroxybutyrate (GHB) plasma concentration (Cmax) was 65.8 ± 4.0 µg/mL for ON-SXB vs 77.1 ± 4.9 µg/mL for twice-nightly SXB (GMR [90% CI], 88.3 [80.5-97.0]). The GMR (90% CI) for GHB plasma concentrations 8 h post dose (C8h) for ON-SXB vs twice-nightly SXB was 61.7 (45.8-83.0). The most frequently reported adverse events were the same for ON-SXB and twice-nightly SXB (nausea, dizziness, somnolence, vomiting). CONCLUSIONS: GHB exposure and Cmax with one 6-g dose of ON-SXB were bioequivalent to those with two 3-g doses of twice-nightly SXB, whereas C8h was lower with ON-SXB. If approved, ON-SXB will provide a single bedtime oxybate option, with clinically relevant pharmacologic exposure during the entire sleep period.

Consensus guidelines on the construct validity of rodent models of restless legs syndrome.

Our understanding of the causes and natural course of restless legs syndrome (RLS) is incomplete. The lack of objective diagnostic biomarkers remains a challenge for clinical research and for the development of valid animal models. As a task force of preclinical and clinical scientists, we have previously defined face validity parameters for rodent models of RLS. In this article, we establish new guidelines for the construct validity of RLS rodent models. To do so, we first determined and agreed on the risk, and triggering factors and pathophysiological mechanisms that influence RLS expressivity. We then selected 20 items considered to have sufficient support in the literature, which we grouped by sex and genetic factors, iron-related mechanisms, electrophysiological mechanisms, dopaminergic mechanisms, exposure to medications active in the central nervous system, and others. These factors and biological mechanisms were then translated into rodent bioequivalents deemed to be most appropriate for a rodent model of RLS. We also identified parameters by which to assess and quantify these bioequivalents. Investigating these factors, both individually and in combination, will help to identify their specific roles in the expression of rodent RLS-like phenotypes, which should provide significant translational implications for the diagnosis and treatment of RLS.

Genetic evidence for a potential causal relationship between insomnia symptoms and suicidal behavior: a Mendelian randomization study.

Insomnia and restless leg syndrome (RLS) are associated with increased risk for suicidal behavior (SB), which is often comorbid with mood or thought disorders; however, it is unclear whether these relationships are causal. We performed a two-sample Mendelian randomization study using summary-level genetic associations with insomnia symptoms and RLS against the outcomes of risk of major depressive disorder (MDD), bipolar disorder (BP), schizophrenia (SCZ), and SB. The inverse-variance weighted method was used in the main analysis. We performed replication and sensitivity analyses to examine the robustness of the results. We identified outcome cohorts for MDD (n = 170,756 cases/329,443 controls), BP (n = 20,352/31,358), SCZ (n = 69,369/236,642), SB-Cohort-2019 (n = 6569/14,996 all with MDD, BP or SCZ; and SB within individual disease categories), and SB-Cohort-2020 (n = 29,782/519,961). Genetically proxied liability to insomnia symptoms significantly associated with increased risk of MDD (odds ratio (OR) = 1.23, 95% confidence interval (CI) = 1.2-1.26, P = 1.37 × 10-61), BP (OR = 1.15, 95% CI = 1.07-1.23, P = 5.11 × 10-5), SB-Cohort-2019 (OR = 1.17, 95% CI = 1.07-1.27, P = 2.30 × 10-4), SB-Cohort-2019 in depressed patients (OR = 1.34, 95% CI = 1.16-1.54, P = 5.97 × 10-5), and SB-Cohort-2020 (OR = 1.24, 95% CI = 1.18-1.3, P = 1.47 × 10-18). Genetically proxied liability to RLS did not significantly influence the risk of any of the outcomes (all corrected P > 0.05). Results were replicated for insomnia with MDD and SB in Mass General Brigham Biobank and were consistent in multiple lines of sensitivity analyses. In conclusion, human genetic evidence supports for the first time a potentially independent and causal effect of insomnia on SB and encourages further clinical investigation of treatment of insomnia for prevention or treatment of SB.

How effective are treatment guidelines for augmented RLS?

STUDY OBJECTIVES: The objective of this study was to assess the effectiveness of current treatment guidelines for restless legs syndrome (RLS) augmentation in patients on dopamine agonists (DAs) which recommend a cross-titration strategy to an alpha-2-delta ligand (A2D) and/or opioid. METHODS: Consecutive new consultations for RLS with both augmentation and active treatment with DAs at the time of initial assessment were included if followed >5 months. Clinical information from the semi-structured initial consultation, and subsequent visits until their most recent/final visit was extracted. Clinical Global Impression-Severity (CGI-S) and Clinical Global Impression-Improvement (CGI-I) scores were retrospectively determined by two independent evaluators. RESULTS: In the 63 patients with augmented RLS on DAs, followed for 5-59 months (mean = 28, SD = 14), the average age was 67.6 (SD = 9.8) and 63% were female. Mean duration of prior dopaminergic therapy was 11.6 years (SD = 6.7) and average pramipexole equivalent dose was 1.23 mg (SD = 1.22 mg). At baseline, RLS was "moderate-markedly" severe (CGI-S = 4.9). At the final/most recent visit, 78% (49/63) were classified as Responders (CGI-I ≤ 2, "Much" or "Very Much Improved") with an average CGI-S of 2.4 ("borderline-mildly ill"). Responders (59%) were more likely to have discontinued DAs than Non-Responders (40%), and mean opioid doses were higher in Responders (39 vs 20 MME). No differences in baseline DA dose, final A2D dose, or iron therapy were observed between groups. Responders did have significantly more severe RLS, more sleep maintenance insomnia, and greater subjective daytime sleepiness at baseline (p < 0.05). CONCLUSIONS: Guideline-based management is effective in most patients with augmented RLS on DAs.

Treating Severe Refractory and Augmented Restless Legs Syndrome.

Restless legs syndrome (RLS) is a sensory-motor neurologic disorder present to a clinically significant degree in 2% to 3% of the adult population, more commonly with advancing age and in women, that dramatically affects sleep and quality of life. Addressing factors that worsen RLS (eg, iron deficiency, antidepressant or antihistamine administration, OSA) is an important first step in treatment. RLS can generally be well treated with medications such as the alpha2-delta calcium channel ligands (A2Ds) gabapentin, pregabalin, and gabapentin enacarbil or, if these are poorly tolerated or lack efficacy, the dopamine agonists (DAs) pramipexole, ropinirole, or rotigotine. Oral or IV iron supplementation is often efficacious as initial treatment in patients with low normal serum indexes. However, at least one-third of patients do not achieve acceptable symptom relief from initial treatments. Furthermore, DAs, the most commonly used medications for RLS, commonly produce augmentation, a progressive, long-term, iatrogenic worsening of RLS symptoms characterized by increasing severity as well as temporal and anatomic extension of symptoms. If dopaminergic augmentation of RLS is present, substitution of an A2D or opioid for the DA is the primary goal. However, given the profound rebound RLS and insomnia that occurs with even small dose reductions of DAs, the initial change should be the addition of one of these alternate treatments. Once adequate doses, or symptom relief, are achieved with the second agent, subsequent very slow down-titration and discontinuation of the DA is often possible and can lead to dramatic long-term relief of RLS symptoms and improvement in sleep.

Restless Legs Syndrome in X-linked adrenoleukodystrophy.

OBJECTIVE/BACKGROUND: X-linked adrenoleukodystrophy (ALD) is a neurodegenerative disease that causes progressive gait and balance problems. Leg discomfort, sleep disturbances, and pain contribute to daily disability. We sought to investigate the prevalence and severity of Restless Legs Syndrome (RLS) in patients with ALD. PATIENTS/METHODS: We administered questionnaires and conducted diagnostic telephone interviews to assess RLS severity. We retrospectively extracted data from neurological examinations, functional gait measures, and laboratory assessments. RESULTS AND CONCLUSIONS: Thirty-two adults with ALD (21 female, 11 male) were recruited to participate. Thirteen patients (40.6%) had RLS (10/21 females and 3/11 males). The median age of RLS onset was 35 years [IQR = 22-54]. Patients with RLS had more signs and symptoms related to myelopathy, but not the brain demyelination seen in ALD. This pilot study suggests a high prevalence of RLS in adults with ALD, which may contribute to sleep problems and impair quality of life.

Aggregating heart rate variability indices across sleep stage epochs ignores significant variance through the night.

BACKGROUND: Heart rate variability (HRV) is a widely utilized biomarker of autonomic regulatory functioning, and concomitant health and pathological states. A growing body of work is exploring HRV under sleeping conditions. Most of this literature utilizes either averaged HRV indices calculated from multiple sleep stage epochs, or averaged HRV throughout the night. Both approaches implicitly assume that HRV within sleep epoch types is consistent throughout the night. Given the robust literature indicating the existence of an endogenous cardiovascular circadian rhythm as well as the potential for effects for cumulative time asleep, we hypothesized that HRV would vary across distinct sleep epochs. METHODS: Participants underwent at least one night of home polysomnography that included electroencephalogram, electromyogram, and electrocardiogram (N = 73). All rapid eye movement (REM) and non-REM stage 2 (N2) sleep epochs with a duration greater than or equal to 5 min were identified for HRV analysis. Time and frequency domain indices of HRV were calculated for each sleep stage epoch. Linear mixed models were used to examine main effects of time on HRV indices for N2 and REM sleeps epochs respectively. RESULTS: Main effects of time were observed for all models. Patterns emerged for both the N2 and REM epochs, suggesting HRV indices are non-stationary (ie variable) across distinct sleep epochs through the course of the night. CONCLUSIONS: The present findings indicate HRV is non-stationary across sleep stage epochs. Aggregating HRV indices across sleep stage epochs likely obscures important transient effects and increases risk of type-I and type-II errors.