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Antelmi E, Mogavero MP, Lanza G, Cartella SM, Ferini-Strambi L, Plazzi G, Ferri R, Tinazzi M. Sensory aspects of restless legs syndrome: Clinical, neurophysiological and neuroimaging prospectives. Sleep Med Rev 2024; 76:101949. [PMID: 38749362 DOI: 10.1016/j.smrv.2024.101949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 11/20/2023] [Accepted: 04/29/2024] [Indexed: 07/26/2024]
Abstract
Restless Legs Syndrome (RLS) is a complex sensorimotor disorder, classified among the sleep-related movement disorders. Although sensory symptoms appear as key features of the disorder, they are still poorly characterized from a clinical perspective and conceptualized from a pathophysiological point of view. In this review, we aim to describe the clinical and functional substrates of RLS, focusing mainly on its sensory symptoms and on their neurophysiological and anatomical correlates. Knowledge of both subjective sensory symptoms and objective sensory signs are still controversial. Current data also indicate that the sensory component of RLS seems to be subserved by anomalies of sensorimotor integration and by mechanism of central sensitization. Overall, electrophysiological findings highlight the involvement of multiple generators in the pathogenesis of RLS, eventually resulting in an increased nervous system excitability and/or alterations in inhibition within the somatosensory and nociceptive pathways. Structural and functional neuroimaging data show the involvement of several crucial areas and circuits, among which the thalamus appears to play a pivotal role. A holistic approach looking at brain connectivity, structural or functional abnormalities, and their interplay with molecular vulnerability and neurotransmitter alterations is warranted to disentangle the complex framework of RLS.
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Affiliation(s)
- Elena Antelmi
- Neurology Unit, Parkinson Disease and Movement Disorders Division, DIMI Department of Engineering and Medicine of Innovation, University of Verona, Italy.
| | - Maria P Mogavero
- Vita-Salute San Raffaele University, Milan, Italy; San Raffaele Scientific Institute, Division of Neuroscience, Sleep Disorders Center, Milan, Italy
| | - Giuseppe Lanza
- Clinical Neurophysiology Research Unit, Oasi Research Institute-IRCCS, Troina, Italy; University of Catania, Department of Surgery and Medical-Surgical Specialties, Catania, Italy
| | - Sandy M Cartella
- Movement Disorders Centre, Department of Neurology, Policlinico "Madonna Della Consolazione", Reggio Calabria, Italy
| | - Luigi Ferini-Strambi
- Vita-Salute San Raffaele University, Milan, Italy; San Raffaele Scientific Institute, Division of Neuroscience, Sleep Disorders Center, Milan, Italy
| | - Giuseppe Plazzi
- IRCCS, Istituto Delle Scienze Neurologiche di Bologna, Bologna, Italy; Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Raffaele Ferri
- Clinical Neurophysiology Research Unit, Oasi Research Institute-IRCCS, Troina, Italy
| | - Michele Tinazzi
- Neurology Unit, Parkinson Disease and Movement Disorders Division, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Italy
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Gorantla S, Ravisankar A, Trotti LM. Magnesium citrate monotherapy improves restless legs syndrome symptoms and multiple suggested immobilization test scores in an open-label pilot study. J Clin Sleep Med 2024; 20:1357-1361. [PMID: 38738598 PMCID: PMC11294134 DOI: 10.5664/jcsm.11206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 05/03/2024] [Accepted: 05/03/2024] [Indexed: 05/14/2024]
Abstract
STUDY OBJECTIVES An estimated 3% of the population has clinically significant restless legs syndrome. Given the limited pharmacological options in the arsenal, there is a need for a therapeutic agent with a better side effect profile. METHODS Twelve treatment naive adults (10 women and 2 men with a median age of 41.5 [32-48.5] years) with primary restless legs syndrome were recruited in our open-label pilot study; magnesium citrate 200 mg was administered daily for 8 weeks. Serum magnesium levels, International Restless Legs Syndrome Study Group Rating Scale, Kohnen quality of life scale, and multiple suggested immobilization tests (three 1-hour tests) were performed before and after supplementation. Paired t tests and Wilcoxon signed-rank tests were used for data analysis. Pearson and Spearman's analyses assessed the association between magnesium levels and restless legs syndrome variables. RESULTS Participants had a significant reduction in International Restless Legs Syndrome Study Group Rating Scale scores (6.67 [2.33-11] P = .006) and improved Kohnen quality of life scores (8.5 [2.09-14], P = .014) without notable differences in serum magnesium levels (P = .3). The median periodic limb movements during wakefulness index (30.40 [5.20, 122.40] to 8.63 [0.32, 17.47] P = .043) and self-reported discomfort score (19 [14, 30.5] to 6 [0, 8] P = .0010) of all 3 multiple suggested immobilization test trials also demonstrated improvement. Serum magnesium levels negatively correlated with multiple suggested immobilization test self-reported scores and the periodic limb movements during wakefulness indices. CONCLUSIONS Despite the limitations of open-label design, our study's positive results indicate the need for a placebo-controlled trial with a larger sample size. CLINICAL TRIAL REGISTRATION Registry: ClinicalTrials.gov; Name: The Effect of Magnesium Citrate Supplementation in Restless Legs Syndrome (RLS); URL: https://clinicaltrials.gov/ct2/show/study/NCT04462796; Identifier: NCT04462796. CITATION Gorantla S, Ravisankar A, Trotti LM. Magnesium citrate monotherapy improves restless legs syndrome symptoms and multiple suggested immobilization test scores in an open-label pilot study. J Clin Sleep Med. 2024;20(8):1357-1361.
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Affiliation(s)
- Sasikanth Gorantla
- Department of Neurology, University of Illinois College of Medicine at Peoria and OSF HealthCare, Peoria, Illinois
- Department of Neurology, University of California, Davis, Sacramento, California
| | - Ashwath Ravisankar
- Department of Neurology, University of Illinois College of Medicine at Peoria and OSF HealthCare, Peoria, Illinois
| | - Lynn Marie Trotti
- Department of Neurology, Emory University School of Medicine, Atlanta, Georgia
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Li YS, Yeh WC, Chang YH, Hsu CY. Restless legs syndrome in patients with epilepsy: risk analysis, polysomnography, and quality of life evaluation. Sleep 2024; 47:zsad054. [PMID: 36861219 DOI: 10.1093/sleep/zsad054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 01/14/2023] [Indexed: 03/03/2023] Open
Abstract
STUDY OBJECTIVES Restless legs syndrome (RLS) is a circadian rhythm related sensorimotor disorder due to brain iron deficiency, with lesion sites at the putamen and substantia nigra. However, epilepsy is a disease with abnormal electric discharge from the cortex and can be triggered with iron disequilibrium. We designed a case-control study to discover the association between epilepsy and RLS. METHODS A total of 24 patients with epilepsy and RLS and 72 patients with epilepsy without RLS were included. Most of the patients underwent polysomnography and video electroencephalogram tests and took sleep questionnaires. We collected information on seizure characteristics, including general or focal onset, epileptogenic focus, current antiseizure medications, medically responsive epilepsy or refractory epilepsy, and nocturnal attacks. The sleep architectures of the two groups were compared. We analyzed the risk factors for RLS using multivariate logistic regression. RESULTS Among the patients with epilepsy, the occurrence of RLS was associated with refractory epilepsy (OR 6.422, p = 0.002) and nocturnal seizures (OR 4.960, p = 0.005). Sleep parameters were not significantly associated with RLS status. Quality of life was significantly impaired in the group with RLS in both the physical and mental domains. CONCLUSIONS Refractory epilepsy and nocturnal seizures were strongly correlated with RLS in patients with epilepsy. RLS should be considered a predictable comorbidity in patients with epilepsy. The management of RLS not only led to better control of the patient's epilepsy but also improved their quality of life.
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Affiliation(s)
- Ying-Sheng Li
- Sleep Disorders Center, Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan
| | - Wei-Chih Yeh
- Department of Neurology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan
| | - Ya-Hsien Chang
- Department of Pediatrics, Yucheng Otolaryngological and Pediatric Clinic, Kaohsiung City, Taiwan
| | - Chung-Yao Hsu
- Sleep Disorders Center, Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
- Department of Neurology, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan
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Hartley S, Bao G, Russo A, Zagdoun M, Chevallier S, Lofaso F, Leotard A, Azabou E. Self-administered non-invasive vagus nerve stimulation therapy for severe pharmacoresistant restless legs syndrome: outcomes at 6 months. J Sleep Res 2024; 33:e14066. [PMID: 37846650 DOI: 10.1111/jsr.14066] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 09/26/2023] [Accepted: 09/27/2023] [Indexed: 10/18/2023]
Abstract
Severe pharmacoresistant restless legs syndrome (RLS) is difficult to manage and a source of suffering to patients. We studied the effectiveness at 6 months of an innovative treatment: transauricular vagus nerve stimulation (taVNS) in the left cymba concha in a case series of 15 patients, 53% male, mean (SD) age 62.7 (12.3) years with severe pharmacoresistant RLS (mean [SD] International Restless Legs Rating Scale [IRLS] score of 31.9 [2.9]) at baseline. Following an 8-week non-randomised hospital-based study with eight 1-h sessions of taVNS, patients were trained to administer taVNS at home and were followed up for 6 months. The primary outcome measure was the IRLS score, secondary outcome measures were quality of life, mood disorders using the Hospital Anxiety and Depression scale (HAD) subscales for depression (HADD) and anxiety (HADA). At the 6-month follow-up 13/15 patients continued to use weekly taVNS. Symptom severity decreased (mean [SD] IRLS score 22.2 [9.32] at 6 months, p = 0.0005). Four of the 15 patients had an IRLS score of <20 at 6 months and two an IRLS score of 5. Quality of life significantly improved compared to baseline (mean [SD] score at baseline 49.3 [18.1] versus 65.66 [22.58] at 6 months, p = 0.0005) as did anxiety and depression symptoms (mean [SD] HADA score at baseline 8.9 [5.4] versus 7.53 [4.42] at 6 months, p = 0.029; and HADD score at baseline 5.2 [4.5] versus 4.73 [4.44] at 6 months, p = 0.03). Treatment was well tolerated, and no adverse events were reported. Our case series shows a potential role for self-administered taVNS in patients with severe pharmacoresistant RLS. Randomised controlled trials are needed to confirm the utility of taVNS.
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Affiliation(s)
- Sarah Hartley
- Sleep Unit, Department of Physiology, Raymond Poincaré Hospital, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Guillaume Bao
- Clinical Neurophysiology and Neuromodulation Unit, SMART_VNS Platform, Department of Physiology, Raymond Poincaré Hospital, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Laboratory of Infection and Inflammation (2I) INSERM UMR 1173, University of Versailles Saint-Quentin-en-Yvelines (UVSQ), Paris-Saclay University, Paris, France
| | - Ashley Russo
- Clinical Neurophysiology and Neuromodulation Unit, SMART_VNS Platform, Department of Physiology, Raymond Poincaré Hospital, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Laboratory of Infection and Inflammation (2I) INSERM UMR 1173, University of Versailles Saint-Quentin-en-Yvelines (UVSQ), Paris-Saclay University, Paris, France
| | - Marine Zagdoun
- Clinical Neurophysiology and Neuromodulation Unit, SMART_VNS Platform, Department of Physiology, Raymond Poincaré Hospital, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Laboratory of Infection and Inflammation (2I) INSERM UMR 1173, University of Versailles Saint-Quentin-en-Yvelines (UVSQ), Paris-Saclay University, Paris, France
| | - Sylvain Chevallier
- Versailles Engineering Systems Laboratory (LISV), University of Versailles Saint-Quentin-en-Yvelines (UVSQ), Vélizy, France
| | - Frédéric Lofaso
- Sleep Unit, Department of Physiology, Raymond Poincaré Hospital, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Clinical Neurophysiology and Neuromodulation Unit, SMART_VNS Platform, Department of Physiology, Raymond Poincaré Hospital, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Laboratory « End:icap », INSERM UMR 1179, University of Versailles Saint-Quentin-en-Yvelines (UVSQ), Paris-Saclay University, Paris, France
| | - Antoine Leotard
- Sleep Unit, Department of Physiology, Raymond Poincaré Hospital, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Laboratory « End:icap », INSERM UMR 1179, University of Versailles Saint-Quentin-en-Yvelines (UVSQ), Paris-Saclay University, Paris, France
| | - Eric Azabou
- Clinical Neurophysiology and Neuromodulation Unit, SMART_VNS Platform, Department of Physiology, Raymond Poincaré Hospital, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Laboratory of Infection and Inflammation (2I) INSERM UMR 1173, University of Versailles Saint-Quentin-en-Yvelines (UVSQ), Paris-Saclay University, Paris, France
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Suzuki K, Suzuki S, Haruyama Y, Funakoshi K, Fujita H, Sakuramoto H, Hamaguchi M, Kobashi G, Hirata K. Associations between the burdens of comorbid sleep problems, central sensitization, and headache-related disability in patients with migraine. Front Neurol 2024; 15:1373574. [PMID: 38601337 PMCID: PMC11006273 DOI: 10.3389/fneur.2024.1373574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 02/15/2024] [Indexed: 04/12/2024] Open
Abstract
Objective Sleep disturbances are common in migraine patients and affect quality of life. Central sensitization (CS) is likely to play a role in the increased severity and chronicity of migraine. We hypothesized that the number of comorbid sleep problems would affect headache-related disability through the effects of central sensitization (CS). Methods We performed a cross-sectional study including 215 consecutive patients with migraine. Insomnia was defined as a Pittsburgh Sleep Quality Index (PSQI) global score greater than 5. Probable REM sleep behavior disorder (pRBD) was defined as an RBD screening score of 5 or greater. Excessive daytime sleepiness (EDS) was defined as an Epworth Sleepiness Scale score of 10 or higher. Suspected sleep apnea (SA) was defined as patients with snoring or sleep apnea witnessed 3 or more nights a week. CS was assessed by the Central Sensitization Inventory (CSI). Results Restless legs syndrome, insomnia, EDS, SA and pRBD were observed in 25.6%, 71.6%, 34.4%, 10.2%, and 21.4%, respectively, of the patients. At least one sleep problem was present in 87.0% of the patients. According to the results of the multinomial logistic regression analysis with no sleep problems as a reference, after we corrected for adjustment factors, the Migraine Disability Assessment (MIDAS) score significantly increased when three or more comorbid sleep problems were present. According to our mediation analysis, an increased number of sleep problems had a direct effect on the MIDAS score after we adjusted for other variables, and the CSI score was indirectly involved in this association. Conclusion The present study showed an association between migraine-related disability and the burden of multiple sleep problems, which was partially mediated by CS.
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Affiliation(s)
- Keisuke Suzuki
- Department of Neurology, Dokkyo Medical University, Mibu, Japan
| | - Shiho Suzuki
- Department of Neurology, Dokkyo Medical University, Mibu, Japan
| | - Yasuo Haruyama
- Integrated Research Faculty for Advanced Medical Sciences, Dokkyo Medical University, Mibu, Japan
| | - Kei Funakoshi
- Department of Neurology, Dokkyo Medical University, Mibu, Japan
| | - Hiroaki Fujita
- Department of Neurology, Dokkyo Medical University, Mibu, Japan
| | | | - Mai Hamaguchi
- Department of Neurology, Dokkyo Medical University, Mibu, Japan
| | - Gen Kobashi
- Department of Public Health, Dokkyo Medical University, Mibu, Japan
| | - Koichi Hirata
- Department of Neurology, Dokkyo Medical University, Mibu, Japan
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Walters AS, Li Y, Koo BB, Ondo WG, Weinstock LB, Champion D, Afrin LB, Karroum EG, Bagai K, Spruyt K. Review of the role of the endogenous opioid and melanocortin systems in the restless legs syndrome. Brain 2024; 147:26-38. [PMID: 37633259 PMCID: PMC10796165 DOI: 10.1093/brain/awad283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 07/23/2023] [Accepted: 08/01/2023] [Indexed: 08/28/2023] Open
Abstract
Restless legs syndrome (RLS) is responsive to opioid, dopaminergic and iron-based treatments. Receptor blocker studies in RLS patients suggest that the therapeutic efficacy of opioids is specific to the opioid receptor and mediated indirectly through the dopaminergic system. An RLS autopsy study reveals decreases in endogenous opioids, β-endorphin and perhaps Met-enkephalin in the thalamus of RLS patients. A total opioid receptor knock-out (mu, delta and kappa) and a mu-opioid receptor knock-out mouse model of RLS show circadian motor changes akin to RLS and, although both models show sensory changes, the mu-opioid receptor knock mouse shows circadian sensory changes closest to those seen in idiopathic RLS. Both models show changes in striatal dopamine, anaemia and low serum iron. However, only in the total receptor knock-out mouse do we see the decreases in serum ferritin that are normally found in RLS. There are also decreases in serum iron when wild-type mice are administered a mu-opioid receptor blocker. In addition, the mu-opioid receptor knock-out mouse also shows increases in striatal zinc paralleling similar changes in RLS. Adrenocorticotropic hormone and α-melanocyte stimulating hormone are derived from pro-opiomelanocortin as is β-endorphin. However, they cause RLS-like symptoms and periodic limb movements when injected intraventricularly into rats. These results collectively suggest that an endogenous opioid deficiency is pathogenetic to RLS and that an altered melanocortin system may be causal to RLS as well.
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Affiliation(s)
- Arthur S Walters
- Sleep Division, Department of Neurology, Vanderbilt University Medical Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Yuqing Li
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Brian B Koo
- Sleep Medicine Laboratory, VA Connecticut Health Care System, West Haven, CT 06516, USA
- Yale Center for Restless Legs Syndrome, Yale School of Medicine, New Haven, CT 06520, USA
| | - William G Ondo
- Department of Neurology, Methodist Hospital, Weill Cornell Medical School, Houston, TX 77030, USA
| | - Leonard B Weinstock
- Department of Internal Medicine, Washington University School of Medicine, St.Louis, MO 63130, USA
| | - David Champion
- Sydney Children's Hospital, Department of Pain Medicine, Randwick, NSW 2031, Australia
| | - Lawrence B Afrin
- Hematology/Oncology, AIM Center for Personalized Medicine, Purchase, NY 10577, USA
| | - Elias G Karroum
- Department of Neurology and Rehabilitation Medicine, The George Washington University School of Medicine and Health Sciences, George Washington University, Washington, D.C. 20052, USA
| | - Kanika Bagai
- Sleep Division, Department of Neurology, Vanderbilt University Medical Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Karen Spruyt
- Université Paris Cité, NeuroDiderot Inserm, Paris 75019, France
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Hackethal S, Maino P, Koetsier E, Manconi M. Spinal cord stimulation in severe pharmacoresistant restless legs syndrome-two case reports. Front Neurol 2023; 14:1219881. [PMID: 38099065 PMCID: PMC10720037 DOI: 10.3389/fneur.2023.1219881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 09/18/2023] [Indexed: 12/17/2023] Open
Abstract
Restless legs syndrome is a prevalent, sleep-related sensorimotor disorder with relevant impact on the patients' quality of life. For patients suffering from severe, pharmacoresistant restless legs syndrome, few therapeutic options remain to alleviate symptoms. In this case series, two patients with severe, pharmacoresistant restless legs syndrome were treated with epidural spinal cord stimulation and repeatedly assessed with polysomnography, including sleep structure and periodic limb movements as objective biomarkers not subject to placebo effects, during a 6-month follow-up period. One of the patients experienced excellent short- and long-term efficacy on subjective symptom severity (International RLS Study group rating scale 1 vs. 34 points at 3 months) and objective sleep parameters such as sleep architecture and periodic limb movements during sleep, while the second patient only reported short-term benefits from spinal cord stimulation. Ultimately, both patients opted for removal of the device for inefficacy. Based on the complex pathophysiology of restless legs syndrome and presumed mechanism of action of spinal cord stimulation in chronic pain disorders, we provide a detailed hypothesis on the possible modulating effect of spinal cord stimulation on the key symptoms of restless legs syndrome. Apart from describing a new therapeutic option for pharmacoresistant restless legs syndrome, our findings might also provide further insights into the pathophysiology of the syndrome.
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Affiliation(s)
- Sandra Hackethal
- Sleep Medicine Unit, Neurocenter of Southern Switzerland, Lugano, Switzerland
| | - Paolo Maino
- Pain Management Center, Neurocenter of Southern Switzerland, Lugano, Switzerland
- Faculty of Biomedical Sciences, Università Della Svizzera Italiana, Lugano, Switzerland
| | - Eva Koetsier
- Pain Management Center, Neurocenter of Southern Switzerland, Lugano, Switzerland
- Faculty of Biomedical Sciences, Università Della Svizzera Italiana, Lugano, Switzerland
| | - Mauro Manconi
- Sleep Medicine Unit, Neurocenter of Southern Switzerland, Lugano, Switzerland
- Faculty of Biomedical Sciences, Università Della Svizzera Italiana, Lugano, Switzerland
- Department of Neurology, University Hospital, Inselspital, Bern, Switzerland
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8
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Pagani-Estévez GL, Holland MT, Tippmann-Peikert M, Benarroch EE, Silber MH, Carvalho DZ. Potential therapeutic benefit of spinal cord stimulation in restless legs syndrome: scoping review and mechanistic considerations. PAIN MEDICINE (MALDEN, MASS.) 2023; 24:S18-S23. [PMID: 37833049 DOI: 10.1093/pm/pnad089] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 03/22/2023] [Accepted: 06/26/2023] [Indexed: 10/15/2023]
Abstract
BACKGROUND Restless legs syndrome (RLS) is a prevalent sensorimotor disorder that can dramatically impair sleep quality, daytime function, and quality of life. Although many patients benefit from standard pharmacological therapy, some patients suffer from insufficient treatment response or medication intolerance. Novel treatment approaches are therefore necessary. OBJECTIVE Given the overlap between RLS and pain syndromes in both pathophysiological mechanisms and certain treatment options, we aimed to perform a scoping review of the available evidence on spinal cord stimulation (SCS) for RLS and discuss potential mechanistic implications. METHODS We identified a total of 16 cases of patients with RLS who underwent SCS, all from case reports or case series. DISCUSSION The published evidence is insufficient to assess SCS efficacy in patients with RLS, but SCS remains a promising investigational therapy in RLS on the basis of its potential mitigatory effects in the central hyperexcitability of the sensorimotor cortex through neuromodulation of spinal, subcortical, and cortical areas. A call for further research in this field is presented, with suggestions for future directions and trial designs.
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Affiliation(s)
- Gabriel L Pagani-Estévez
- Department of Interventional and Surgical Pain Management, Cincinnati Veterans Affairs Medical Center, Cincinnati, OH 45220, United States
| | - Marshall T Holland
- Department of Neurosurgery, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Maja Tippmann-Peikert
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, United States
- Center for Sleep Medicine, Pulmonary and Critical Care Medicine Division, Department of Internal Medicine, Mayo Clinic, Rochester, MN 55905, United States
| | | | - Michael H Silber
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, United States
- Center for Sleep Medicine, Pulmonary and Critical Care Medicine Division, Department of Internal Medicine, Mayo Clinic, Rochester, MN 55905, United States
| | - Diego Z Carvalho
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, United States
- Center for Sleep Medicine, Pulmonary and Critical Care Medicine Division, Department of Internal Medicine, Mayo Clinic, Rochester, MN 55905, United States
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9
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Chenini S, Barateau L, Dauvilliers Y. Restless legs syndrome: From clinic to personalized medicine. Rev Neurol (Paris) 2023; 179:703-714. [PMID: 37689536 DOI: 10.1016/j.neurol.2023.08.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/11/2023]
Abstract
Restless legs syndrome (RLS) is a common neurological sensorimotor disorder that impairs sleep, mood and quality of life. RLS is defined by an urge to move the legs at rest that increases in the evening and at night, and is frequently associated with metabolic and cardiovascular diseases. Symptoms frequency, age at RLS onset, severity, familial history and consequences of RLS vary widely between patients. A genetic susceptibility, iron deficiency, dopamine deregulation, and possible hypo-adenosinergic state may play a role in the pathophysiology of RLS. Polysomnographic recordings found often periodic leg movements during sleep and wakefulness in patients with RLS. RLS can be classified as primary or comorbid with major diseases: iron deficiency, renal, neurological, rheumatological and lung diseases. First-line treatments are low-dose dopamine agonists, and alpha-2-delta ligands depending on the clinical context, and second/third line opiates for pharmacoresistant forms of RLS. Augmentation syndrome is a serious complication of dopamine agonists and should be prevented by using the recommended low dose. Despite an increase in knowledge, RLS is still underdiagnosed, poorly recognized, resulting in substantial individual health burden and socioeconomic coast, and education is urgently needed to increase awareness of this disabling disorder.
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Affiliation(s)
- S Chenini
- National Reference Centre for Orphan Diseases Narcolepsy and Rare Hypersomnias, Sleep Unit, Department of Neurology, CHU Montpellier, University of Montpellier, Montpellier, France; Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France.
| | - L Barateau
- National Reference Centre for Orphan Diseases Narcolepsy and Rare Hypersomnias, Sleep Unit, Department of Neurology, CHU Montpellier, University of Montpellier, Montpellier, France; Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
| | - Y Dauvilliers
- National Reference Centre for Orphan Diseases Narcolepsy and Rare Hypersomnias, Sleep Unit, Department of Neurology, CHU Montpellier, University of Montpellier, Montpellier, France; Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France.
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Li Y, Zhao L, Zhang K, Shen M, Li Y, Yu Y, Yu J, Feng J, Xie K, Yu Y. Neurometabolic and structural alterations of medial septum and hippocampal CA1 in a model of post-operative sleep fragmentation in aged mice: a study combining 1H-MRS and DTI. Front Cell Neurosci 2023; 17:1160761. [PMID: 37333891 PMCID: PMC10272368 DOI: 10.3389/fncel.2023.1160761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/17/2023] [Indexed: 06/20/2023] Open
Abstract
Post-operative sleep disturbance is a common feature of elderly surgical patients, and sleep fragmentation (SF) is closely related to post-operative cognitive dysfunction (POCD). SF is characterized by sleep interruption, increased number of awakenings and sleep structure destruction, similar to obstructive sleep apnea (OSA). Research shows that sleep interruption can change neurotransmitter metabolism and structural connectivity in sleep and cognitive brain regions, of which the medial septum and hippocampal CA1 are key brain regions connecting sleep and cognitive processes. Proton magnetic resonance spectroscopy (1H-MRS) is a non-invasive method for the evaluation of neurometabolic abnormalities. Diffusion tensor imaging (DTI) realizes the observation of structural integrity and connectivity of brain regions of interest in vivo. However, it is unclear whether post-operative SF induces harmful changes in neurotransmitters and structures of the key brain regions and their contribution to POCD. In this study, we evaluated the effects of post-operative SF on neurotransmitter metabolism and structural integrity of medial septum and hippocampal CA1 in aged C57BL/6J male mice. The animals received a 24-h SF procedure after isoflurane anesthesia and right carotid artery exposure surgery. 1H-MRS results showed after post-operative SF, the glutamate (Glu)/creatine (Cr) and glutamate + glutamine (Glx)/Cr ratios increased in the medial septum and hippocampal CA1, while the NAA/Cr ratio decreased in the hippocampal CA1. DTI results showed post-operative SF decreased the fractional anisotropy (FA) of white matter fibers in the hippocampal CA1, while the medial septum was not affected. Moreover, post-operative SF aggravated subsequent Y-maze and novel object recognition performances accompanied by abnormal enhancement of glutamatergic metabolism signal. This study suggests that 24-h SF induces hyperglutamate metabolism level and microstructural connectivity damage in sleep and cognitive brain regions in aged mice, which may be involved in the pathophysiological process of POCD.
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Affiliation(s)
- Yun Li
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Research Institute of Anesthesiology, Tianjin, China
| | - Lina Zhao
- Department of Critical Care Medicine, Tianjin Medical University General Hospital, Tianjin, China
| | - Kai Zhang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Research Institute of Anesthesiology, Tianjin, China
| | - Mengxi Shen
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Research Institute of Anesthesiology, Tianjin, China
| | - Yize Li
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Research Institute of Anesthesiology, Tianjin, China
| | - Yang Yu
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Research Institute of Anesthesiology, Tianjin, China
| | - Jiafeng Yu
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Research Institute of Anesthesiology, Tianjin, China
| | - Jingyu Feng
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Research Institute of Anesthesiology, Tianjin, China
| | - Keliang Xie
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Research Institute of Anesthesiology, Tianjin, China
- Department of Critical Care Medicine, Tianjin Medical University General Hospital, Tianjin, China
| | - Yonghao Yu
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Research Institute of Anesthesiology, Tianjin, China
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DelRosso LM, Mogavero MP, Bruni O, Ferri R. Restless Legs Syndrome and Restless Sleep Disorder in Children. Sleep Med Clin 2023; 18:201-212. [PMID: 37120162 DOI: 10.1016/j.jsmc.2023.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Restless legs syndrome (RLS) affects 2% of children presenting with symptoms of insomnia, restless sleep, decreased quality of life, and effects on cognition and behavior. The International RLS Study Group and the American Academy of Sleep Medicine have published guidelines for the diagnosis and treatment of RLS in children. Restless sleep disorder has been recently identified in children and presents with frequent movements during sleep and daytime symptoms with polysomnography findings of at least 5 large muscle movements at night. Treatment options for both disorders include iron supplementation, either oral or intravenous with improvement in nighttime and daytime symptoms.
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Affiliation(s)
- Lourdes M DelRosso
- University of California San Francisco, Fresno, USA; University Sleep and Pulmonary Associates, 6733 North Willow Avenue, Unit 107, Fresno, CA 93710, USA.
| | - Maria Paola Mogavero
- Institute of Molecular Bioimaging and Physiology, National Research Council, Milan, Italy; Division of Neuroscience, Sleep Disorders Center, San Raffaele Scientific Institute, Milan, Italy; Centro di Medicina Del Sonno, IRCCS Ospedale San Raffaele, Turro, Via Stamira D'Ancona, 20, Milano 20127, Italy
| | - Oliviero Bruni
- Department of Social and Developmental Psychology, Sapienza University, Via dei Marsi 78, Rome 00185, Italy
| | - Raffaele Ferri
- Department of Neurology I.C., Sleep Research Centre, Oasi Research Institute - IRCCS, Via C Ruggero 73, Troina 94018, Italy
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Cederberg KLJ, Silvestri R, Walters AS. Vitamin D and Restless Legs Syndrome: A Review of Current Literature. Tremor Other Hyperkinet Mov (N Y) 2023; 13:12. [PMID: 37034443 PMCID: PMC10077981 DOI: 10.5334/tohm.741] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 03/16/2023] [Indexed: 04/08/2023] Open
Abstract
This review presents a detailed summary of the current literature regarding RLS and vitamin D deficiency. To our knowledge it is the first review of its kind. We review the prevalence of vitamin D deficiency in RLS as well as the evidence for the use of vitamin D supplementation in RLS management. We further examine the literature for proteomic and genetic evidence of a role for vitamin D in the pathogenesis of RLS. An alteration in vitamin D binding protein in RLS is one of the most consistent findings in the proteomic studies. Furthermore, we examine the interaction of vitamin D with calcium, phosphorus, and parathyroid hormone and the possible role of these connections in RLS. We also explore the possible nexus between RLS and vitamin D in renal disease, cardiovascular and cerebrovascular disease as well as inflammation. In addition, we review the potential interaction between vitamin D and RLS with iron, dopamine and other neurotransmitter systems including the endogenous opiate, serotoninergic, glutamatergic and adenosinergic systems. We also explore the role of vitamin D in RLS Augmentation (i.e., the paradoxical worsening of RLS symptoms when dopaminergic agents are used as a therapy for RLS). Although the literature is not entirely consistent in affirming vitamin D deficiency in RLS or the amelioration of RLS symptoms with vitamin D therapy, the collective studies overall indicate that vitamin D deficiency is common enough in RLS patients to suggest that RLS patients should have their vitamin D levels checked and any deficiency corrected as a standard of care. Highlights Patients with Restless Legs Syndrome (RLS) may be deficient in vitamin D and therapy with vitamin D may ameliorate RLS. We present the first review dedicated solely to evaluating the relationship between RLS and vitamin D and present a case for the role of vitamin D in RLS pathogenesis.
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Affiliation(s)
- Katie L. J. Cederberg
- Department of Psychiatry & Behavioral Sciences, Stanford University, 3165 Porter Drive Palo Alto, CA, USA
| | - Rosalia Silvestri
- Department of Clinical and Experimental Medicine, Sleep Medicine Center, University of Messina, Azienda Ospedaliera Universitaria “Gaetano Martino”, Messina, Italy
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Morais MA, Franco BS, Holanda ASS, de Paula Simino LA, Veras ACC, Torsoni MA, Manconi M, Torsoni AS, Esteves AM. Protein tyrosine phosphatase receptor type delta (PTPRD) gene in an animal model of restless legs syndrome. J Sleep Res 2023; 32:e13716. [PMID: 36053904 DOI: 10.1111/jsr.13716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 07/21/2022] [Accepted: 07/27/2022] [Indexed: 11/28/2022]
Abstract
The pathophysiology of the restless legs syndrome (RLS) is related to dopaminergic dysfunction, reduced iron and variations in gene expression, such as the protein tyrosine phosphatase receptor type delta gene (PTPRD). Animal models could be key to achieving a mechanistic understanding of RLS and to facilitate efficient platforms for evaluating new therapeutics. Thus, the aim of this study was to evaluate the expression of PTPRD, of genes and proteins associated with RLS, the sleep patterns and the cardiovascular parameters in an animal model of RLS (spontaneously hypertensive rat [SHR]). Rats were divided into two groups: (i) Wistar-Kyoto and (ii) SHR. Cardiovascular parameters were assessed by tail plethysmography. Polysomnography was used to analyse the sleep pattern (24 h). For the PTPRD analyses, quantitative polymerase chain reaction (qPCR) and indirect enzyme-linked immunosorbent assay (ELISA) techniques were used. To evaluate the tyrosine hydroxylase enzyme, dopamine transporter (DAT) and type 2 dopaminergic receptor, qPCR and Western Blotting techniques were used. For the quantification of iron, ferritin and transferrin, the ELISA method was used. SHRs had higher blood pressure, alterations in sleep pattern, lower expression of protein content of PTPRD, lower expression of DAT, and lower serum concentrations of ferritin. These data suggest that the behavioural, physiological, and molecular changes observed in SHRs provide a useful animal model of RLS, reinforcing the importance of this strain as an animal model of this sleep disorder.
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Affiliation(s)
- Milca Abda Morais
- Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Limeira, Brazil
| | - Beatriz Silva Franco
- Faculdade de Educação Física, Universidade Estadual de Campinas, Campinas, Brazil
| | | | | | | | | | - Mauro Manconi
- Sleep and Epilepsy Center, Neurocenter of Southern Switzerland, Civic Hospital of Lugano (EOC), Lugano, Switzerland
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Riccardi S, Ferri R, Garbazza C, Miano S, Manconi M. Pharmacological responsiveness of periodic limb movements in patients with restless legs syndrome: a systematic review and meta-analysis. J Clin Sleep Med 2023; 19:811-822. [PMID: 36692194 PMCID: PMC10071388 DOI: 10.5664/jcsm.10440] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 12/06/2022] [Accepted: 12/06/2022] [Indexed: 01/25/2023]
Abstract
STUDY OBJECTIVES Periodic limb movements during sleep (PLMS) are a frequent finding in restless legs syndrome, but their impact on sleep is still debated, as well the indication for treatment. We systematically reviewed the available literature to describe which drug categories are effective in suppressing PLMS, assessing their efficacy through a meta-analysis, when this was possible. METHODS The review protocol was preregistered on PROSPERO (CRD42021175848), and the systematic search was conducted on and EMBASE (last searched on March 2020). We included original human studies, which assessed PLMS modification on drug treatment with a full-night polysomnography, through surface electrodes on each tibialis anterior muscle. When at least 4 studies were available on the same drug or drug category, we performed a random-effect model meta-analysis. RESULTS Dopamine agonists like pramipexole and ropinirole resulted the most effective, followed by l-dopa and other dopamine agonists. Alpha2delta ligands are moderately effective as well opioids, despite available data on these drugs are much more limited than those on dopaminergic agents. Valproate and carbamazepine did not show a significant effect on PLMS. Clonazepam showed contradictory results. Perampanel and dypiridamole showed promising but still insufficient data. The same applies to iron supplementation. CONCLUSIONS Dopaminergic agents are the most powerful suppressors of PLMS. However, most therapeutic trials in restless legs syndrome do not report objective polysomnographic findings, there is a lack of uniformity in presenting results on PLMS. Longitudinal polysomnographic interventional studies, using well-defined and unanimous scoring criteria and endpoints on PLMS are needed. CITATION Riccardi S, Ferri R, Garbazza C, Miano S, Manconi M. Pharmacological responsiveness of periodic limb movements in patients with restless legs syndrome: a systematic review and meta-analysis. J Clin Sleep Med. 2023;19(4):811-822.
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Affiliation(s)
- Silvia Riccardi
- Sleep Medicine Unit, Regional Hospital of Lugano, Neurocenter of Southern Switzerland, Lugano, Switzerland
| | - Raffaele Ferri
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy
| | - Corrado Garbazza
- Sleep Medicine Unit, Regional Hospital of Lugano, Neurocenter of Southern Switzerland, Lugano, Switzerland
| | - Silvia Miano
- Sleep Medicine Unit, Regional Hospital of Lugano, Neurocenter of Southern Switzerland, Lugano, Switzerland
| | - Mauro Manconi
- Sleep Medicine Unit, Regional Hospital of Lugano, Neurocenter of Southern Switzerland, Lugano, Switzerland
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McCarter SJ, Labott JR, Mazumder MK, Gebhard J, Cunningham JL, Loukianova LL, Gilliam WP, Lipford MC. Emergence of restless legs syndrome during opioid discontinuation. J Clin Sleep Med 2023; 19:741-748. [PMID: 36692170 PMCID: PMC10071383 DOI: 10.5664/jcsm.10436] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 12/05/2022] [Accepted: 12/05/2022] [Indexed: 01/25/2023]
Abstract
STUDY OBJECTIVES The development of restless legs syndrome (RLS) has been rarely reported during and following opioid withdrawal. We aimed to determine the presence and severity of RLS symptoms during and after supervised opioid tapering. METHODS Ninety-seven adults enrolled in the Mayo Clinic Pain Rehabilitation Center who underwent supervised prescription opioid tapering were prospectively recruited. RLS presence and severity was assessed with the Cambridge-Hopkins Questionnaire 13 and International Restless Legs Syndrome Study Group Rating Severity Scale at admission, midpoint, and dismissal from the program as well as 2 weeks, 4 weeks, and 3 months after completion. Frequency and severity of RLS symptoms were compared between admission and each time point. RESULTS Average age of the cohort was 52.6 ± 13.3 years with a morphine milligram equivalent dose for the cohort of 45.6 ± 48.3 mg. Frequency of RLS symptoms increased from 28% at admission to peak frequency of 41% at 2 weeks following discharge from the Mayo Pain Rehabilitation Clinic (P = .01), returning to near baseline frequency 3 months after opioid discontinuation. International Restless Legs Syndrome Study Group Rating Severity Scale increased from baseline and then remained relatively stable at each time point following admission. Thirty-five (36.1%) participants developed de novo symptoms of RLS during their opioid taper, with those being exposed to higher morphine milligram equivalent doses having higher risk of developing RLS. CONCLUSIONS Moderately severe symptoms of RLS, as assessed by survey, occur commonly in individuals undergoing opioid tapering, particularly if exposed to higher doses. In many cases, symptoms appear to be self-limited, although a minority develop persistent symptoms. Our results may have implications for successful opioid tapering, but future confirmatory studies with structured clinician interview are needed to establish that these symptoms truly represent restless legs syndrome given the potential for RLS-mimicking symptoms in individuals with chronic pain syndromes. CITATION McCarter SJ, Labott JR, Mazumder MK, et al. Emergence of restless legs syndrome during opioid discontinuation. J Clin Sleep Med. 2023;19(4):741-748.
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Affiliation(s)
- Stuart J. McCarter
- Center for Sleep Medicine, Mayo Clinic, Mayo Clinic College of Medicine, Rochester, Minnesota
- Department of Neurology, Mayo Clinic, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Joshua R. Labott
- Department of Orthopedics, Mayo Clinic, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Mridul K. Mazumder
- Department of Geriatric Psychiatry Florida State University, Tallahassee, Florida
| | - Judy Gebhard
- Department of Psychiatry and Psychology, Mayo Clinic, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Julie L. Cunningham
- Department of Pharmacy and Mayo Clinic, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Larissa L. Loukianova
- Department of Psychiatry and Psychology, Mayo Clinic, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Wesley P. Gilliam
- Department of Psychiatry and Psychology, Mayo Clinic, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Melissa C. Lipford
- Center for Sleep Medicine, Mayo Clinic, Mayo Clinic College of Medicine, Rochester, Minnesota
- Department of Neurology, Mayo Clinic, Mayo Clinic College of Medicine, Rochester, Minnesota
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Restless Legs Syndrome and Periodic Limb Movements of Sleep: From Neurophysiology to Clinical Practice. J Clin Neurophysiol 2023; 40:215-223. [PMID: 36872500 DOI: 10.1097/wnp.0000000000000934] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023] Open
Abstract
SUMMARY This article summarizes restless legs syndrome (RLS), periodic limb movements of sleep, and periodic limb movement disorder. RLS is a common sleep disorder with a prevalence of 5% to 15% in the general population. RLS can present in childhood, and incidence increases with age. RLS can be idiopathic or secondary to iron deficiency, chronic renal failure, peripheral neuropathy, and medications such as antidepressants (with higher rates for mirtazapine and venlafaxine, while bupropion may reduce symptoms at least in the short term), dopamine antagonists (neuroleptic antipsychotic agents and antinausea medications), and possibly antihistamines. Management includes pharmacologic agents (dopaminergic agents, alpha-2 delta calcium channel ligands, opioids, benzodiazepines) and nonpharmacologic therapies (iron supplementation, behavioral management). Periodic limb movements of sleep are an electrophysiologic finding commonly accompanying RLS. On the other hand, most individuals with periodic limb movements of sleep do not have RLS. The clinical significance of the movements has been argued. Periodic limb movement disorder is a distinct sleep disorder that arises in individuals without RLS and is a diagnosis of exclusion.
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Tang M, Sun Q, Zhang Y, Li H, Wang D, Wang Y, Wang Z. Circadian rhythm in restless legs syndrome. Front Neurol 2023; 14:1105463. [PMID: 36908590 PMCID: PMC9995399 DOI: 10.3389/fneur.2023.1105463] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 02/07/2023] [Indexed: 02/25/2023] Open
Abstract
Restless legs syndrome (RLS) is a sensorimotor disorder with a obvious circadian rhythm, as its symptoms often occur or worsen only in the evening or at night. The mechanisms behind the rhythms of RLS have not yet been fully elucidated. This review explores possible causes for the circadian fluctuations of the symptomatology, including the levels of iron, dopamine, melatonin, melanocortin, and thyroid-stimulating hormone in the brain, as well as conditions such as peripheral hypoxia and microvascular function disorders. The metabolic disturbances of the substances above can create a pathological imbalance, which is further aggravated by physiological fluctuations of circadian rhythms, and results in the worsening of RLS symptoms at night. The review concludes with the suggestions for RLS treatment and research directions in the future.
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Affiliation(s)
- Mingyang Tang
- Sleep Center, Department of Neurology, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Qingqing Sun
- Sleep Center, Department of Neurology, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Yanan Zhang
- Sleep Center, Department of Neurology, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Huimin Li
- Sleep Center, Department of Neurology, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Dong Wang
- Sleep Center, Department of Neurology, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Ying Wang
- Sleep Center, Department of Neurology, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Zan Wang
- Sleep Center, Department of Neurology, The First Hospital of Jilin University, Changchun, Jilin, China
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A Narrative Review of the Lesser Known Medications for Treatment of Restless Legs Syndrome and Pathogenetic Implications for Their Use. Tremor Other Hyperkinet Mov (N Y) 2023; 13:7. [PMID: 36873914 PMCID: PMC9983500 DOI: 10.5334/tohm.739] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 02/11/2023] [Indexed: 03/06/2023] Open
Abstract
Background There are several well-known treatments for Restless Legs Syndrome (RLS), including dopamine agonists (pramipexole, ropinirole, rotigotine), anticonvulsants (gabapentin and its analogs, pregabalin), oral or intravenous iron, opioids and benzodiazepines. However, in clinical practice, treatment is sometimes limited due to incomplete response or side effects and it is necessary to be aware of other treatment options for RLS, which is the purpose of this review. Methods We performed a narrative review detailing all of the lesser known pharmacological treatment literature on RLS. The review purposefully excludes well-established, well-known treatments for RLS which are widely accepted as treatments for RLS in evidence-based reviews. We also have emphasized the pathogenetic implications for RLS of the successful use of these lesser known agents. Results Alternative pharmacological agents include clonidine which reduces adrenergic transmission, adenosinergic agents such as dipyridamole, glutamate AMPA receptor blocking agents such as perampanel, glutamate NMDA receptor blocking agents such as amantadine and ketamine, various anticonvulsants (carbamazepine/oxcarbazepine, lamotrigine, topiramate, valproic acid, levetiracetam), anti-inflammatory agents such as steroids, as well as cannabis. Bupropion is also a good choice for the treatment of co-existent depression in RLS because of its pro-dopaminergic properties. Discussion Clinicians should first follow evidence-based review recommendations for the treatment of RLS but when the clinical response is either incomplete or side effects are intolerable other options can be considered. We neither recommend nor discourage the use of these options, but leave it up to the clinician to make their own choices based upon the benefit and side effect profiles of each medication. Summary Clinicians should first follow evidence-based reviews for RLS but when response is incomplete and side effects intolerable, other medications can be considered. We do not make a recommendation on these options but leave it up to the clinician to make their own choice based upon the benefit and side effect profiles of each medication.
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Zhang H, Zhang Y, Ren R, Yang L, Shi Y, Vitiello MV, Sanford LD, Tang X. Polysomnographic features of idiopathic restless legs syndrome: a systematic review and meta-analysis of 13 sleep parameters and 23 leg movement parameters. J Clin Sleep Med 2022; 18:2561-2575. [PMID: 35903949 PMCID: PMC9622979 DOI: 10.5664/jcsm.10160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 02/05/2023]
Abstract
STUDY OBJECTIVES This study aims to explore the polysomnographically measured sleep and leg movement differences between idiopathic restless legs syndrome (RLS) patients and healthy controls. METHODS An electronic literature search was conducted in EMBASE, MEDLINE, all EBM databases, CINAHL, and PsycINFO. Only observational case-control studies were included in the meta-analysis. The differences in 13 sleep parameters and 23 leg movement parameters between RLS patients and healthy controls were explored. RESULTS Thirty-eight studies were identified for systematic review, 31 of which were used for meta-analysis. Meta-analyses revealed significant reductions in total sleep time, sleep efficiency, stage N2 and rapid eye movement (REM) sleep percentages, and increases in wake time after sleep onset, stage shifts per hour, stage N1 percentage, REM latency, arousal index, and apnea-hypopnea index. Some leg movement parameters, such as periodic limb movement during sleep (PLMS) index, PLMS sequence duration, number of PLMS sequence, and periodicity index, were higher in RLS patients compared with healthy controls. Further, our meta-analysis revealed a higher PLMS index during non-REM sleep compared with that during REM sleep. CONCLUSIONS RLS patients manifest a lightening of sleep, increased sleep fragmentation, and greater sleep-related breathing disruption and limb movements during sleep relative to healthy normal individuals. The distributions of PLMS during a night's sleep may provide more information to clarify the specific characteristics of leg movements in RLS. PLMS in RLS are concentrated in non-REM sleep. The periodicity index may be a more sensitive and specific marker of RLS than the PLMS index. CITATION Zhang H, Zhang Y, Ren R, et al. Polysomnographic features of idiopathic restless legs syndrome: a systematic review and meta-analysis of 13 sleep parameters and 23 leg movement parameters. J Clin Sleep Med. 2022;18(11):2561-2575.
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Affiliation(s)
- Haipeng Zhang
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine, Mental Health Center, and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Ye Zhang
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine, Mental Health Center, and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Rong Ren
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine, Mental Health Center, and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Linghui Yang
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine, Mental Health Center, and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yuan Shi
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine, Mental Health Center, and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Michael V. Vitiello
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington
| | - Larry D. Sanford
- Sleep Research Laboratory, Center for Integrative Neuroscience and Inflammatory Diseases, Department of Pathology and Anatomy, Eastern Virginia Medical School, Norfolk, Virginia
| | - Xiangdong Tang
- Sleep Medicine Center, Department of Respiratory and Critical Care Medicine, Mental Health Center, and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
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Earley CJ, Jones BC, Ferré S. Brain-iron deficiency models of restless legs syndrome. Exp Neurol 2022; 356:114158. [PMID: 35779614 PMCID: PMC9357217 DOI: 10.1016/j.expneurol.2022.114158] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 06/24/2022] [Accepted: 06/25/2022] [Indexed: 11/04/2022]
Abstract
Restless legs syndrome (RLS) is a common sensorimotor disorder for which two main pathological elements are fairly well accepted: Brain iron deficiency (BID) and an altered dopaminergic system. The ability to better understand the causal and consequential factors related to these two pathological elements, would hopefully lead to the development of better therapeutic strategies for treating, if not curing, this disease. The current understanding of the relationship between these two elements is that BID leads to some alterations in neurotransmitters and subsequent changes in the dopaminergic system. Therefore, rodent models based on diet-induced BID, provide a biological substrate to understand the consequences of BID on dopaminergic pathway and on alternative pathways that may be involved. In this review, we present the current research on dopaminergic changes found in RLS subjects and compare that to what is seen in the BID rodent model to provide a validation of the BID rodent model. We also demonstrate the ability of the BID model to predict changes in other neurotransmitter systems and how that has led to new treatment options. Finally, we will present arguments for the utility of recombinant inbred mouse strains that demonstrate natural variation in brain iron, to explore the genetic basis of altered brain iron homeostasis as a model to understand why in idiopathic RLS there can exist a BID despite normal peripheral iron store. This review is the first to draw on 25 years of human and basic research into the pathophysiology of RLS to provide strong supportive data as to the validity of BID model as an important translational model of the disease. As we will demonstrate here, not only does the BID model closely and accurately mimic what we see in the dopaminergic system of RLS, it is the first model to identify alternative systems from which new treatments have recently been developed.
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Affiliation(s)
- Christopher J Earley
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Byron C Jones
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Sergi Ferré
- Integrative Neurobiology Section, National Institutes of Health/National Institute on Drug Abuse, Baltimore, MD, USA
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Geng C, Yang Z, Zhang T, Xu P, Zhang H. Polysomnographic nighttime features of Restless Legs Syndrome: A systematic review and meta-analysis. Front Neurol 2022; 13:961136. [PMID: 36090852 PMCID: PMC9452633 DOI: 10.3389/fneur.2022.961136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 07/29/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundRestless Legs Syndrome (RLS) is a common sleep disorder. Polysomnographic (PSG) studies have been used to explore the night sleep characteristics of RLS, but their relationship with RLS has not been fully analyzed and researched.MethodsWe searched the Cochrane Library electronic literature, PubMed, and EMBASE databases to identify research literature comparing the differences in polysomnography between patients with RLS and healthy controls (HCs).ResultsThis review identified 26 studies for meta-analysis. Our research found that the rapid eye movement sleep (REM)%, sleep efficiency (SE)%, total sleep time (TST) min, and N2 were significantly decreased in patients with RLS compared with HCs, while sleep latency (SL) min, stage shifts (SS), awakenings number (AWN), wake time after sleep onset (WASO) min, N1%, rapid eye movement sleep latency (REML), and arousal index (AI) were significantly increased. Additionally, there was no significant difference among N3%, slow wave sleep (SWS)%, and apnea-hypopnea index (AHI).ConclusionOur findings demonstrated that architecture and sleep continuity had been disturbed in patients with RLS, which further illustrates the changes in sleep structure in patients with RLS. In addition, further attention to the underlying pathophysiological mechanisms of RLS and its association with neurodegenerative diseases is needed in future studies.
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Affiliation(s)
- Chaofan Geng
- Henan University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, China
| | - Zhenzhen Yang
- Fuwai Central China Cardiovascular Hospital, Henan Provincial People's Hospital, Zhengzhou, China
| | - Tingting Zhang
- Henan University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, China
| | - Pengfei Xu
- Henan University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, China
| | - Hongju Zhang
- Henan University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, China
- Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, China
- *Correspondence: Hongju Zhang
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22
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Wen Q, Zhou J, Sun X, Ma T, Liu Y, Xie Y, Wang L, Cheng J, Wen J, Wu J, Zou J, Liu S, Liu J. Urine metabolomics analysis of sleep quality in deep-underground miners: A pilot study. Front Public Health 2022; 10:969113. [PMID: 36062104 PMCID: PMC9437423 DOI: 10.3389/fpubh.2022.969113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 08/01/2022] [Indexed: 01/25/2023] Open
Abstract
Background In previous questionnaire surveys of miners, sleep disorders were found among underground workers. The influence of the special deep-underground environment and its potential mechanism are still unclear. Therefore, this study intends to utilize LC-MS metabolomics to study the potential differences between different environments and different sleep qualities. Methods Twenty-seven miners working at 645-1,500 m deep wells were investigated in this study, and 12 local ground volunteers were recruited as the control group. The Pittsburgh Sleep Quality Index (PSQI) was used to examine and evaluate the sleep status of the subjects in the past month, and valuable basic information about the participants was collected. PSQI scores were obtained according to specific calculation rules, and the corresponding sleep grouping and subsequent analysis were carried out. Through liquid chromatography-mass spectrometry (LC-MS) non-targeted metabolomics analysis, differences in metabolism were found by bioinformatics analysis in different environments. Results Between the deep-underground and ground (DUvsG) group, 316 differential metabolites were identified and 125 differential metabolites were identified in the good sleep quality vs. poor sleep quality (GSQvsPSQ) group. The metabolic pathways of Phenylalanine, tyrosine and tryptophan biosynthesis (p = 0.0102) and D-Glutamine and D-glutamate metabolism (p = 0.0241) were significantly enriched in DUvsG. For GSQvsPSQ group, Butanoate metabolism was statistically significant (p = 0.0276). L-Phenylalanine, L-Tyrosine and L-Glutamine were highly expressed in the deep-underground group. Acetoacetic acid was poorly expressed, and 2-hydroxyglutaric acid was highly expressed in good sleep quality. Conclusions The influence of the underground environment on the human body is more likely to induce specific amino acid metabolism processes, and regulate the sleep-wake state by promoting the production of excitatory neurotransmitters. The difference in sleep quality may be related to the enhancement of glycolytic metabolism, the increase in excitatory neurotransmitters and the activation of proinflammation. L-phenylalanine, L-tyrosine and L-glutamine, Acetoacetic acid and 2-hydroxyglutaric acid may be potential biomarkers correspondingly.
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Affiliation(s)
- Qiao Wen
- Department of Otolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China,Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jing Zhou
- Department of Otolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China,Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Xiaoru Sun
- Department of Otolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China,Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Tengfei Ma
- Department of Otolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China,Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Yilin Liu
- Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China,Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
| | - Yike Xie
- Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Ling Wang
- Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Juan Cheng
- Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jirui Wen
- Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jiang Wu
- Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jian Zou
- Department of Otolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China,Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China
| | - Shixi Liu
- Department of Otolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China,Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China,Shixi Liu
| | - Jifeng Liu
- Department of Otolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China,Deep Underground Space Medical Center, West China Hospital, Sichuan University, Chengdu, China,*Correspondence: Jifeng Liu
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23
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Salminen AV, Clemens S, García-Borreguero D, Ghorayeb I, Li Y, Manconi M, Ondo W, Rye D, Siegel JM, Silvani A, Winkelman JW, Allen RP, Ferré S. Consensus guidelines on the construct validity of rodent models of restless legs syndrome. Dis Model Mech 2022; 15:dmm049615. [PMID: 35946581 PMCID: PMC9393041 DOI: 10.1242/dmm.049615] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 07/10/2022] [Indexed: 12/16/2022] Open
Abstract
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.
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Affiliation(s)
- Aaro V. Salminen
- Institute of Neurogenomics, Helmholtz Zentrum München GmbH - German Research Center for Environmental Health, 85764 Neuherberg, Germany
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, 81675 Munich, Germany
| | - Stefan Clemens
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
| | | | - Imad Ghorayeb
- Département de Neurophysiologie Clinique, Pôle Neurosciences Cliniques, CHU de Bordeaux, 33076 Bordeaux, France
- Université de Bordeaux, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, UMR 5287, 33076 Bordeaux, France
- CNRS, Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, UMR 5287, 33076 Bordeaux, France
| | - Yuqing Li
- Department of Neurology, Norman Fixel Institute for Neurological Diseases, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Mauro Manconi
- Sleep Medicine Unit, Regional Hospital of Lugano, Neurocenter of Southern Switzerland, 6900 Lugano, Switzerland
- Faculty of Biomedical Sciences, Università della Svizzera Italiana, 6900 Lugano, Switzerland
- Department of Neurology, University Hospital Inselspital, 3010 Bern, Switzerland
| | - William Ondo
- Houston Methodist Hospital Neurological Institute, Weill Cornell Medical School, Houston, TX 77070, USA
| | - David Rye
- Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jerome M. Siegel
- Neuropsychiatric Institute and Brain Research Institute, University of California, Los Angeles, CA 90095, USA
- Neurobiology Research, Veterans Administration Greater Los Angeles Healthcare System, North Hills, CA 91343, USA
| | - Alessandro Silvani
- Department of Biomedical and Neuromotor Sciences Alma Mater Studiorum, Università di Bologna, 48121 Ravenna Campus, Ravenna, Italy
| | - John W. Winkelman
- Departments of Psychiatry and Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Richard P. Allen
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21224, USA
| | - Sergi Ferré
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
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Khachatryan SG, Ferri R, Fulda S, Garcia‐Borreguero D, Manconi M, Muntean M, Stefani A. Restless legs syndrome: Over 50 years of European contribution. J Sleep Res 2022; 31:e13632. [PMID: 35808955 PMCID: PMC9542244 DOI: 10.1111/jsr.13632] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 11/28/2022]
Abstract
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.
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Affiliation(s)
- Samson G. Khachatryan
- Department of Neurology and NeurosurgeryNational Institute of HealthYerevanArmenia
- Sleep Disorders CenterSomnus Neurology ClinicYerevanArmenia
| | | | - Stephany Fulda
- Sleep Medicine UnitNeurocenter of Southern Switzerland, Ospedale CivicoLuganoSwitzerland
| | | | - Mauro Manconi
- Sleep Medicine UnitNeurocenter of Southern Switzerland, Ospedale CivicoLuganoSwitzerland
- Department of NeurologyUniversity HospitalInselspitalBernSwitzerland
| | - Maria‐Lucia Muntean
- Center for Parkinson's Disease and Movement DisordersParacelsus‐Elena KlinikKasselGermany
| | - Ambra Stefani
- Sleep Disorders Clinic, Department of NeurologyMedical University of InnsbruckInnsbruckAustria
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25
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Drakatos P, Olaithe M, Verma D, Ilic K, Cash D, Fatima Y, Higgins S, Young AH, Chaudhuri KR, Steier J, Skinner T, Bucks R, Rosenzweig I. Periodic limb movements during sleep: a narrative review. J Thorac Dis 2022; 13:6476-6494. [PMID: 34992826 PMCID: PMC8662505 DOI: 10.21037/jtd-21-1353] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 10/20/2021] [Indexed: 01/02/2023]
Abstract
Objective Using narrative review techniques, this paper evaluates the evidence for separable underlying patho-mechanisms of periodic limb movements (PLMs) to separable PLM motor patterns and phenotypes, in order to elucidate potential new treatment modalities. Background Periodic limb movement disorder (PLMD) is estimated to occur in 5–8% of the paediatric population and 4–11% of the general adult population. Due to significant sleep fragmentation, PLMD can lead to functional impairment, including hyperactivity and delayed language development in children, and poor concentration and work performance in adults. Longitudinal data demonstrate that those with PLMD are at greater risk of depression and anxiety, and a 4-fold greater risk of developing dementia. PLMD has been extensively studied over the past two decades, and several key insights into the genetic, pathophysiological, and neural correlates have been proposed. Amongst these proposals is the concept of separable PLM phenotypes, proposed on the basis of nocturnal features such as the ratio of limb movements and distribution throughout the night. PLM phenotype and presentation, however, varies significantly depending on the scoring utilized and the nocturnal features examined, across age, and co-morbid clinical conditions. Furthermore, associations between these phenotypes with major neurologic and psychiatric disorders remain controversial. Methods In order to elucidate potential divergent biological pathways that may help clarify important new treatment modalities, this paper utilizes narrative review and evaluates the evidence linking PLM motor patterns and phenotypes with hypothesised underlying patho-mechanisms. Distinctive, underlying patho-mechanisms include: a pure motor mechanism originating in the spinal cord, iron deficiency, dopamine system dysfunction, thalamic glutamatergic hyperactivity, and a more cortical-subcortical interplay. In support of the latter hypothesis, PLM rhythmicity appears tightly linked to the microarchitecture of sleep, not dissimilarly to the apnoeic/hypopneic events seen in obstructive sleep apnea (OSA). Conclusions This review closes with a proposal for greater investigation into the identification of potential, divergent biological pathways. To do so would require prospective, multimodal imaging clinical studies which may delineate differential responses to treatment in restless legs syndrome (RLS) without PLMS and PLMS without RLS. This could pave the way toward important new treatment modalities.
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Affiliation(s)
- Panagis Drakatos
- Sleep and Brain Plasticity Centre, CNS, IoPPN, King's College London, London, UK.,Sleep Disorders Centre, Guy's and St Thomas' Hospital, GSTT NHS, London, UK.,Faculty of Life and Sciences Medicine, King's College London, London, UK
| | - Michelle Olaithe
- School of Psychological Science, University of Western Australia, Perth, Western Australia, Australia
| | - Dhun Verma
- Sleep and Brain Plasticity Centre, CNS, IoPPN, King's College London, London, UK
| | - Katarina Ilic
- Sleep and Brain Plasticity Centre, CNS, IoPPN, King's College London, London, UK.,BRAIN, Imaging Centre, CNS, King's College London, London, UK
| | - Diana Cash
- Sleep and Brain Plasticity Centre, CNS, IoPPN, King's College London, London, UK.,BRAIN, Imaging Centre, CNS, King's College London, London, UK
| | - Yaqoot Fatima
- Institute for Social Science Research, University of Queensland, Brisbane, Australia.,Centre for Rural and Remote Health, James Cook University, Mount Isa, Australia
| | - Sean Higgins
- Sleep and Brain Plasticity Centre, CNS, IoPPN, King's College London, London, UK.,Sleep Disorders Centre, Guy's and St Thomas' Hospital, GSTT NHS, London, UK
| | - Allan H Young
- School of Academic Psychiatry, King's College London, London, UK
| | - K Ray Chaudhuri
- King's College London and Parkinson's Foundation Centre of Excellence, King's College Hospital, London, UK
| | - Joerg Steier
- Sleep Disorders Centre, Guy's and St Thomas' Hospital, GSTT NHS, London, UK.,Faculty of Life and Sciences Medicine, King's College London, London, UK
| | - Timothy Skinner
- Institute of Psychology, University of Copenhagen, Copenhagen, Denmark.,La Trobe Rural Health School, La Trobe University, Bendigo, Victoria, Australia
| | - Romola Bucks
- School of Psychological Science, University of Western Australia, Perth, Western Australia, Australia.,The Raine Study, University of Western Australia, Perth, Australia
| | - Ivana Rosenzweig
- Sleep and Brain Plasticity Centre, CNS, IoPPN, King's College London, London, UK.,Sleep Disorders Centre, Guy's and St Thomas' Hospital, GSTT NHS, London, UK
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26
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Geng C, Yang Z, Kong X, Xu P, Zhang H. Correlation between vitamin D and poor sleep status in restless legs syndrome. Front Endocrinol (Lausanne) 2022; 13:994545. [PMID: 36187108 PMCID: PMC9519848 DOI: 10.3389/fendo.2022.994545] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 08/29/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Restless Legs Syndrome (RLS) is closely related to poorer sleep quality. Vitamin D can regulate sleep regulation, cell proliferation, and differentiation. To measure whether vitamin D has predictive value for poor sleep quality in RLS was our aim in this study. METHODS To analyze the serum levels of 25-hydroxyvitamin D [25(OH)D] in 95 RLS patients. We used the Pittsburgh Sleep Quality Index (PSQI) to measure sleep quality. Subjects had been divided into a normal and poor-sleeper groups according to the PSQI score. Using correlation and regression analysis to explore underlying etiologies that affect sleep disorder in RLS patients. RESULTS Patients in the poor-sleeper group had significantly lower vitamin D levels in comparison to the normal group. The serum vitamin D levels were negative correlate with PSQI scores after adjusting for confounding factors. In addition, regression analysis showed that vitamin D could act as a predictor for sleep disorders in RLS patients (odds ratio [OR] = 0.008, p = 0.004). The area under the curve (AUC), cut-off value, sensitivity, and specificity of serum vitamin D was 0.967 (95% CI 0.935-0.998), 16.84 ng/ml, 87.5%, and 93.7% by receiver operating characteristic (ROC) analysis. CONCLUSION Our study confirmed the relationship between poorer sleep quality and vitamin D in RLS. However, the causal relationship between vitamin D deficiency and RLS is currently inconclusive. The effect of vitamin D supplementation is needed to confirm as the therapeutic strategies for sleep disorders in RLS patients in future work.
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Affiliation(s)
- Chaofan Geng
- Henan University People’s Hospital, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Zhenzhen Yang
- Fuwai Central China Cardiovascular Hospital, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Xiumei Kong
- Henan University Joint National Laboratory for Antibody Drug Engineering, Kaifeng, China
| | - Pengfei Xu
- Henan Provincial Chest Hospital, Zhengzhou, China
| | - Hongju Zhang
- Henan University People’s Hospital, Henan Provincial People’s Hospital, Zhengzhou, China
- Zhengzhou University People’s Hospital, Henan Provincial People’s Hospital, Zhengzhou, China
- *Correspondence: Hongju Zhang,
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27
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Basaran S, Akıncı E. Screening autonomic functions in patients with restless legs syndrome: A case-control study in a tertiary care hospital. Auton Neurosci 2021; 237:102924. [PMID: 34871924 DOI: 10.1016/j.autneu.2021.102924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 09/28/2021] [Accepted: 11/16/2021] [Indexed: 10/19/2022]
Abstract
PURPOSE The clinical importance of autonomic involvement in patients with restless legs syndrome (RLS) remains unclear. To our knowledge, no study has explored the relationship between autonomic dysfunction and disease-related variables in patients with RLS. Therefore, this study aimed 1) to determine the presence of autonomic symptoms in drug-naïve patients with RLS in comparison with healthy controls using Scales for Outcomes in Parkinson's disease-Autonomic (SCOPA-AUT) questionnaire and 2) to evaluate the possible associations of autonomic dysfunction with clinical factors in RLS. METHODS A total of 70 drug-naïve patients with RLS and 85 healthy volunteers were enrolled. The SCOPA-AUT questionnaire and Epworth Sleepiness Scale (ESS) scores were used to determine autonomic functions and sleep propensity, respectively. Moreover, the International Restless Legs Syndrome Study Group rating scale was used to evaluate disease severity in the patient group. RESULTS Compared with the control group, the RLS group had significantly higher subscale scores (gastrointestinal, urinary, cardiovascular, thermoregulatory, pupillomotor, and sexual [women]) and total scores of the SCOPA-AUT questionnaire (p < 0.05). In the patient group, there was a significant correlation between the total scores and subscale scores (gastrointestinal, cardiovascular, and thermoregulatory subscales) of the SCOPA-AUT questionnaire and disease severity. Moreover, ESS was positively correlated with the total scores and subscale scores (urinary, cardiovascular, and pupillomotor) of the SCOPA-AUT questionnaire. CONCLUSION Disease severity and daytime sleepiness may be related to autonomic dysfunction in RLS. Further studies focusing on autonomic functions in RLS are required to improve management strategies and clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov. NCT04906486; May 28, 2021.
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Affiliation(s)
- Sehnaz Basaran
- Department of Neurology, Kocaeli Derince Training and Research Hospital, Kocaeli, Turkey.
| | - Erhan Akıncı
- Department of Psychiatry, Canakkale Onsekiz Mart University Medicine Faculty, Canakkale, Turkey.
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28
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Mogavero MP, Mezzapesa DM, Savarese M, DelRosso LM, Lanza G, Ferri R. Morphological analysis of the brain subcortical gray structures in restless legs syndrome. Sleep Med 2021; 88:74-80. [PMID: 34740168 DOI: 10.1016/j.sleep.2021.10.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 10/12/2021] [Accepted: 10/14/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Although several studies have shown the involvement of specific structures of the central nervous system, the dopaminergic system, and iron metabolism in restless legs syndrome (RLS), the exact location and extent of its anatomical substrate is not yet known. The scope of this new study was to investigate the brain subcortical gray structures, by means of structural magnetic resonance imaging (MRI) studies, in RLS patients in order to assess the presence of any volume or shape abnormalities involving these structures. METHODS Thirty-three normal controls (24 females and nine males) and 45 RLS patients (34 females and 11 males) were retrospectively recruited and underwent a 1.5 Tesla MRI study with two-dimensional T1 sequences in the sagittal plane. Post-processing was performed by means of the Functional Magnetic Resonance Imaging of the Brain Analysis Group Integrated Registration and Segmentation Tool (FIRST) software, and both volumetric and morphological analyses of the thalamus, caudate, putamen, globus pallidus, brainstem, hippocampus, and amygdala, bilaterally, were carried out. RESULTS A statistically significant volumetric reduction in the left amygdala and left globus pallidus was found in subjects with RLS, as well as large surface morphological alterations affecting the amygdala bilaterally and other less widespread surface changes in both hippocampi, the right caudate, the left globus pallidus, and the left putamen. CONCLUSIONS These findings seem to indicate that the basic mechanisms of RLS might include a pathway involving not only the hypothalamus-spinal dopaminergic circuit (nucleus A11), but also pathways including the basal ganglia and structures that are part of the limbic system; moreover, structural alterations in RLS seem to concern the morphology as well as the volume of the above structures. The role of basal ganglia in the complex neurophysiological and neurochemical mechanism of RLS needs to carefully reconsidered.
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Affiliation(s)
- Maria P Mogavero
- Istituti Clinici Scientifici Maugeri, IRCCS, Scientific Institute of Pavia, Italy
| | - Domenico M Mezzapesa
- Neurology Unit and Stroke Center, Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
| | - Mariantonietta Savarese
- Neurology Unit and Stroke Center, Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
| | - Lourdes M DelRosso
- Seattle Children's Hospital and University of Washington, Seattle, WA, USA
| | - Giuseppe Lanza
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy; Department of Neurology I.C., Oasi Research Institute - IRCCS, Troina, Italy
| | - Raffaele Ferri
- Department of Neurology I.C., Oasi Research Institute - IRCCS, Troina, Italy.
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29
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Abstract
Restless legs syndrome (RLS) is a common sensorimotor disorder characterized by an urge to move that appears during rest or is exacerbated by rest, that occurs in the evening or night and that disappears during movement or is improved by movement. Symptoms vary considerably in age at onset, frequency and severity, with severe forms affecting sleep, quality of life and mood. Patients with RLS often display periodic leg movements during sleep or resting wakefulness. RLS is considered to be a complex condition in which predisposing genetic factors, environmental factors and comorbidities contribute to the expression of the disorder. RLS occurs alone or with comorbidities, for example, iron deficiency and kidney disease, but also with cardiovascular diseases, diabetes mellitus and neurological, rheumatological and respiratory disorders. The pathophysiology is still unclear, with the involvement of brain iron deficiency, dysfunction in the dopaminergic and nociceptive systems and altered adenosine and glutamatergic pathways as hypotheses being investigated. RLS is poorly recognized by physicians and it is accordingly often incorrectly diagnosed and managed. Treatment guidelines recommend initiation of therapy with low doses of dopamine agonists or α2δ ligands in severe forms. Although dopaminergic treatment is initially highly effective, its long-term use can result in a serious worsening of symptoms known as augmentation. Other treatments include opioids and iron preparations.
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30
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Evidente VGH, Evidente DH, Ponce FA, Evidente MH, Lambert M, Garrett R. Thalamic Deep Brain Stimulation May Improve Restless Legs Syndrome in Patients With Essential Tremor. Neuromodulation 2021; 25:911-917. [PMID: 34520594 DOI: 10.1111/ner.13532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 07/20/2021] [Accepted: 08/16/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To determine change in restless legs syndrome (RLS) symptoms in essential tremor (ET) patients undergoing bilateral thalamic ventral intermedius (VIM) deep brain stimulation (DBS) surgery. MATERIALS AND METHODS We retrospectively reviewed our database of ET patients with RLS who had undergone VIM DBS for tremor from 2012 to 2020. We reviewed the patients with available International Restless Leg Syndrome Study Group RLS scale scores before and after DBS. Percentage of responders, defined as proportion of patients experiencing three or more point improvement of RLS scores post-DBS, was calculated. We performed two-tailed t-test of pre-DBS and post-DBS RLS scores. RESULTS We identified 13 patients with ET and RLS who had undergone bilateral VIM DBS, of whom nine (69%) were responders post-DBS. Five of 13 patients (38%) had complete resolution of RLS post-DBS. For all patients, mean pre-DBS RLS score was 15.8 ± 7.9 which improved by 46% post-DBS to a mean of 8.5 ± 8.8 (p = 0.007). Four patients rated their RLS scale one night with the stimulator OFF and another night with the stimulator ON. The mean RLS score with stimulator ON was 15.5 ± 7.6 which improved by 53% to a mean of 6.25 ± 7.8 (p = 0.008), with two having complete resolution of RLS with stimulator ON. Of the nine responders, six preferred to keep their stimulator ON at night due to relief of RLS and better subjective quality of sleep. CONCLUSIONS We report for the first time improvement of RLS in patients with ET after bilateral thalamic DBS. Although many ET patients with nonrechargeable DBS systems switch off their stimulator at night to conserve battery life, those with RLS may potentially benefit from keeping their stimulator ON at night to relieve their RLS.
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Affiliation(s)
| | | | | | | | | | - Robin Garrett
- Movement Disorders Center of Arizona, Scottsdale, AZ, USA
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Riccitelli GC, Disanto G, Sacco R, Sparasci D, Sacco L, Castelnovo A, Miano S, Manconi M, Gobbi C, Zecca C. Contribution of sleep disturbances to fatigue in multiple sclerosis: a prospective study using clinical and polysomnographic parameters. Eur J Neurol 2021; 28:3139-3146. [PMID: 34143510 PMCID: PMC8457159 DOI: 10.1111/ene.14984] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/20/2021] [Accepted: 06/03/2021] [Indexed: 01/02/2023]
Abstract
BACKGROUND AND PURPOSE Fatigue is amongst the most frequent and disabling symptoms of multiple sclerosis and a close relation between fatigue and sleep quality has been hypothesized. In this study the contribution of sleep disturbances measured by clinical and polysomnographic parameters to fatigue in multiple sclerosis was investigated. METHODS This was a prospective instrumental study performed at the Neurocenter of Southern Switzerland. Demographic data and clinical characteristics including fatigue (as measured by the modified fatigue impact scale [MFIS]), neurological disability, psychiatric symptoms, medications and sleep-related variables were collected at baseline visit and by a home full-night polysomnography. The associations between sleep-related variables and the MFIS were tested using partial correlations adjusted by demographic and sleep-unrelated clinical factors. RESULTS Seventy-six patients were included in the study, of whom 53 (69.7%) had an MFIS ≥38 points (median 49.5, interquartile range 31.0-62.0). MFIS scores were positively associated with age, neurological disability, symptoms of depression and anxiety, and use of benzodiazepines and selective serotonin reuptake inhibitors. When adjusting for these variables, the presence of restless legs syndrome (RLS) (r = 0.37, p = 0.005) and periodic leg movements index (r = -0.33, p = 0.014) were associated with MFIS. Excessive daytime sleepiness, total sleep time, sleep efficiency, respiratory disturbances, and percentage of time spent in the different sleep stages (N1, N2, N3 and rapid eye movement) were not associated with fatigue. CONCLUSIONS Multiple sclerosis patients with a diagnosis of RLS had significantly higher global fatigue scores compared to those without RLS. Future studies should investigate whether medical treatment of RLS can ameliorate fatigue.
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Affiliation(s)
- Gianna C. Riccitelli
- Multiple Sclerosis CenterNeurocenter of Southern SwitzerlandRegional Hospital (EOC) of LuganoLuganoSwitzerland
- Neuropsychology and Behavioral Neurology Research UnitNeurocenter of Southern SwitzerlandRegional Hospital (EOC) of LuganoLuganoSwitzerland
- Faculty of Biomedical SciencesUniversità della Svizzera ItalianaLuganoSwitzerland
| | - Giulio Disanto
- Multiple Sclerosis CenterNeurocenter of Southern SwitzerlandRegional Hospital (EOC) of LuganoLuganoSwitzerland
| | - Rosaria Sacco
- Multiple Sclerosis CenterNeurocenter of Southern SwitzerlandRegional Hospital (EOC) of LuganoLuganoSwitzerland
| | - Davide Sparasci
- Sleep Medicine UnitNeurocenter of Southern SwitzerlandRegional Hospital (EOC) of LuganoLuganoSwitzerland
| | - Leonardo Sacco
- Neuropsychology and Behavioral Neurology Research UnitNeurocenter of Southern SwitzerlandRegional Hospital (EOC) of LuganoLuganoSwitzerland
| | - Anna Castelnovo
- Sleep Medicine UnitNeurocenter of Southern SwitzerlandRegional Hospital (EOC) of LuganoLuganoSwitzerland
- Faculty of Biomedical SciencesUniversità della Svizzera ItalianaLuganoSwitzerland
- University Hospital of Psychiatry and PsychotherapyUniversity of BernBernSwitzerland
| | - Silvia Miano
- Neuropsychology and Behavioral Neurology Research UnitNeurocenter of Southern SwitzerlandRegional Hospital (EOC) of LuganoLuganoSwitzerland
| | - Mauro Manconi
- Sleep Medicine UnitNeurocenter of Southern SwitzerlandRegional Hospital (EOC) of LuganoLuganoSwitzerland
- Faculty of Biomedical SciencesUniversità della Svizzera ItalianaLuganoSwitzerland
- Neurology Department InselspitalBern University HospitalBernSwitzerland
| | - Claudio Gobbi
- Multiple Sclerosis CenterNeurocenter of Southern SwitzerlandRegional Hospital (EOC) of LuganoLuganoSwitzerland
- Faculty of Biomedical SciencesUniversità della Svizzera ItalianaLuganoSwitzerland
| | - Chiara Zecca
- Multiple Sclerosis CenterNeurocenter of Southern SwitzerlandRegional Hospital (EOC) of LuganoLuganoSwitzerland
- Faculty of Biomedical SciencesUniversità della Svizzera ItalianaLuganoSwitzerland
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Xu Y, Wen H, Li J, Yang J, Luo K, Chang L. The relationship between sleep disorders, anxiety, depression, and cognitive function with restless legs syndrome (RLS) in the elderly. Sleep Breath 2021; 26:1309-1318. [PMID: 34436711 DOI: 10.1007/s11325-021-02477-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 08/01/2021] [Accepted: 08/11/2021] [Indexed: 02/07/2023]
Abstract
OBJECTIVES Restless legs syndrome (RLS) has a significant effect on sleep and quality of life. Delays in diagnosis and treatment are frequent due to a lack of awareness. In this study, a clinical analysis was performed to examine the relationship between sleep, mood, and cognitive function in RLS. METHODS According to the Pittsburgh Sleep Quality Index score (PSQI), patients with RLS were divided into a sleep disorders group (SD, PSQI > 7) and non-sleep disorders group (NSD, PSQI ≤ 7). Healthy controls were selected as a control group matched for age, cultural background, and marital status. We compared differences between the three groups using the Hamilton Anxiety Scale (HAMA), Hamilton Depression (HAMD), Mini-Mental State Examination (MMSE), and Montreal Cognitive Assessment (MoCA). The SD and NSD groups were also assessed with the Restless Leg Syndrome Rating Scale (RLSRS) and the severity of RLS between the two groups was compared. The analysis used t-test, ANOVA, and Pearson correlation. RESULTS (1) Among the 54 RLS patients, 30 people in the control group, 35 patients with sleep disorders (SD, 65%), and 19 patients without sleep disorders (NSD, 35%), there were no significant differences in age, educational level, marital status, or trauma history. (2) The comparison results of the case group (SD and NSD) and the control group showed highly significant differences (P < 0.01) in the PSQI-HAMA-HAMD score but no significant differences between the NSD group, the SD group, and the control group in MMSE score. There was no difference between the NSD group and the control group in the MoCA, but a significant difference (P < 0.05) between the SD group and the control group was found. (3) The comparison between the NSD and the SD groups revealed significant differences in the RLSRS, HAMA, and HAMD scores (P < 0.05), but there were no statistical differences (P > 0.05) between two groups on MMSE and MoCA score. (4) Correlation and regression showed that there was a linear correlation between PSQI scores and RLSRS and HAMD scores in patients with RLS (P < 0.05). The regression equation was PSQI = - 2.393 + 0.494 RLSRS + 0.170 HAMD. CONCLUSIONS RLS patients were prone to sleep disorders, anxiety, and depression. Sleep disorders increased with the severity of the RLS and had some influence on the patient's cognitive function. Sleep disorders were closely related to RLSRS and HAMD.
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Affiliation(s)
- Yuan Xu
- Department of Neurology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, People's Republic of China.,Comprehensive Stroke Center, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, People's Republic of China
| | - Hongbin Wen
- Department of Neurology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, People's Republic of China.,Comprehensive Stroke Center, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, People's Republic of China
| | - Jie Li
- Department of Neurology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, People's Republic of China.,Comprehensive Stroke Center, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, People's Republic of China
| | - Jing Yang
- Department of Neurology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, People's Republic of China
| | - Kai Luo
- School of Food Science and Technology & School of Chemical Engineering, Hubei University of Arts and Science, Xiangyang, 441053, People's Republic of China.
| | - Liying Chang
- Department of Neurology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, People's Republic of China.,Comprehensive Stroke Center, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, People's Republic of China
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33
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Shin JW, Sunwoo JS, Byun JI, Kim TJ, Jun JS, Kim WC, Jung KY. Reduced sympatho-vagal responses to orthostatic stress in drug-naïve idiopathic restless legs syndrome. J Clin Sleep Med 2021; 17:957-963. [PMID: 33438574 DOI: 10.5664/jcsm.9074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
STUDY OBJECTIVES Restless legs syndrome (RLS) is known to be a risk factor for cardiovascular disease. However, there are no electrophysiological biomarkers to assess this risk. This study aimed to evaluate heart rate variability (HRV) and cardiovascular reflexes in the supine and standing positions during wakefulness in patients with RLS. METHODS Fourteen drug-naïve patients with RLS (12 women and 2 men, mean age, 42.14 ± 7.81 years) and 10 healthy control patients underwent tests for blood pressure, heart rate when in the supine and standing positions, and deep breathing and handgrip tests in controlled laboratory conditions. Data on 5-minute R-R intervals at each position were collected and analyzed for HRV. RESULTS Expected cardiovascular reflexes were within the normal range and were similar between the 2 groups. In HRV analysis, the normalized unit of the low-frequency component and the low-frequency/high-frequency ratio during standing were lower in patients with RLS than in the control patients. The low-frequency/high-frequency ratio responses during the change from the supine to the standing position were significantly reduced in patients with RLS (mean ± standard deviation, 2.94 ± 3.11; control patients: 7.51 ± 5.58; P = .042.) On Spearman rank correlation, questionnaires related to sleep problems were associated with the parameters of HRV. CONCLUSIONS Patients with RLS showed reduced sympatho-vagal responses during the change from the supine to the upright position during wakefulness, and RLS-related sleep disturbance was a contributing factor for autonomic nervous system dysfunction. This case-control study showed a difference in HRV response to position change in a considerably small group of patients with RLS. The relevance of this finding is uncertain, but it may be worthy of further investigation in longitudinal studies on RLS and cardiovascular disease.
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Affiliation(s)
- Jung-Won Shin
- Department of Neurology, Bundang CHA Medical Center, CHA University, Seongnam, Republic of Korea
| | - Jun-Sang Sunwoo
- Department of Neurosurgery, Seoul National University Hospital, Republic of Korea
| | - Jung-Ick Byun
- Department of Neurology, Kyung Hee University Hospital at Gangdong, Republic of Korea
| | - Tae-Joon Kim
- Department of Neurology, Ajou University School of Medicine, Republic of Korea
| | - Jin-Sun Jun
- Department of Neurology, Kangnam Sacred Heart Hospital, Seoul National University College of Medicine, Republic of Korea
| | - Won Chan Kim
- Department of Neurology, Bundang CHA Medical Center, CHA University, Seongnam, Republic of Korea
| | - Ki-Young Jung
- Department of Neurology, Seoul National University Hospital, Sensory Organ Research Institute, Seoul National University Medical Research Center, Neuroscience Research Institute, Seoul National University College of Medicine, Republic of Korea
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Ferré S, Guitart X, Quiroz C, Rea W, García-Malo C, Garcia-Borreguero D, Allen RP, Earley CJ. Akathisia and Restless Legs Syndrome: Solving the Dopaminergic Paradox. Sleep Med Clin 2021; 16:249-267. [PMID: 33985651 DOI: 10.1016/j.jsmc.2021.02.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Akathisia is an urgent need to move that is associated with treatment with dopamine receptor blocking agents (DRBAs) and with restless legs syndrome (RLS). The pathogenetic mechanism of akathisia has not been resolved. This article proposes that it involves an increased presynaptic dopaminergic transmission in the ventral striatum and concomitant strong activation of postsynaptic dopamine D1 receptors, which form complexes (heteromers) with dopamine D3 and adenosine A1 receptors. It also proposes that in DRBA-induced akathisia, increased dopamine release depends on inactivation of autoreceptors, whereas in RLS it depends on a brain iron deficiency-induced down-regulation of striatal presynaptic A1 receptors.
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Affiliation(s)
- Sergi Ferré
- Integrative Neurobiology Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Triad Building, 333 Cassell Drive, Baltimore, MD 21224, USA.
| | - Xavier Guitart
- Integrative Neurobiology Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Triad Building, 333 Cassell Drive, Baltimore, MD 21224, USA
| | - César Quiroz
- Integrative Neurobiology Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Triad Building, 333 Cassell Drive, Baltimore, MD 21224, USA
| | - William Rea
- Integrative Neurobiology Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Triad Building, 333 Cassell Drive, Baltimore, MD 21224, USA
| | - Celia García-Malo
- Sleep Research Institute, Paseo de la Habana 151, Madrid 28036, Spain
| | | | - Richard P Allen
- Department of Neurology, Johns Hopkins University, Johns Hopkins Bayview Medical Center, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA
| | - Christopher J Earley
- Department of Neurology, Johns Hopkins University, Johns Hopkins Bayview Medical Center, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA
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Chen P, Bornhorst J, Patton S, Bagai K, Nitin R, Miah M, Hare DJ, Kysenius K, Crouch PJ, Xiong L, Rouleau GA, Schwerdtle T, Connor J, Aschner M, Bowman AB, Walters AS. A potential role for zinc in restless legs syndrome. Sleep 2021; 44:zsaa236. [PMID: 33175142 PMCID: PMC8033460 DOI: 10.1093/sleep/zsaa236] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 10/13/2020] [Indexed: 11/14/2022] Open
Abstract
STUDY OBJECTIVES Evaluate serum and brain noniron metals in the pathology and genetics of restless legs syndrome (RLS). METHODS In two independent studies (cohorts 1 and 2), in which subjects either remained on medications or tapered off medications, we analyzed serum levels of iron, calcium, magnesium, manganese, copper, and zinc both in RLS patients and controls, and assessed the prevalence of the MEIS1 and BTBD9 risk alleles previously established through genome-wide association studies. Human brain sections and a nematode genetic model were also quantified for metal levels using mass spectrometry. RESULTS We found a significant enrichment for the BTBD9 risk genotype in the RLS affected group compared to control (p = 0.0252), consistent with previous literature. Serum (p = 0.0458 and p = 0.0139 for study cohorts 1 and 2, respectively) and brain (p = 0.0413) zinc levels were significantly elevated in the RLS patients versus control subjects. CONCLUSION We show for the first time that serum and brain levels of zinc are elevated in RLS. Further, we confirm the BTBD9 genetic risk factor in a new population, although the zinc changes were not significantly associated with risk genotypes. Zinc and iron homeostasis are interrelated, and zinc biology impacts neurotransmitter systems previously linked to RLS. Given the modest albeit statistically significant increase in serum zinc of ~20%, and the lack of association with two known genetic risk factors, zinc may not represent a primary etiology for the syndrome. Further investigation into the pathogenetic role that zinc may play in restless legs syndrome is needed.
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Affiliation(s)
- Pan Chen
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY
| | - Julia Bornhorst
- Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, Germany
| | - Stephanie Patton
- Department of Neurosurgery, Penn State Hershey Medical Center, Hershey, PA
| | - Kanika Bagai
- Department of Neurology, Sleep Division, Vanderbilt University Medical Center, Nashville, TN
| | - Rachana Nitin
- Vanderbilt University, Vanderbilt Brain Institute, Nashville, TN
| | - Mahfuzur Miah
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY
| | - Dominic J Hare
- School of Biosciences, The University of Melbourne, Victoria, Australia
| | - Kai Kysenius
- Department of Pharmacology and Therapeutics, The University of Melbourne, Victoria, Australia
| | - Peter J Crouch
- Department of Pharmacology and Therapeutics, The University of Melbourne, Victoria, Australia
- Florey Institute of Neuroscience and Mental Health, the University of Melbourne, Victoria, Australia
| | - Lan Xiong
- Montreal Neurological Institute, McGill University, Montréal, Québec, Canada
| | - Guy A Rouleau
- Montreal Neurological Institute, McGill University, Montréal, Québec, Canada
| | - Tanja Schwerdtle
- Institute of Nutritional Science, Department of Food Chemistry, University of Potsdam, Nuthetal, Germany
| | - James Connor
- Department of Neurosurgery, Penn State Hershey Medical Center, Hershey, PA
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY
| | - Aaron B Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN
| | - Arthur S Walters
- Department of Neurology, Sleep Division, Vanderbilt University Medical Center, Nashville, TN
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Kaul M, Zee PC, Sahni AS. Effects of Cannabinoids on Sleep and their Therapeutic Potential for Sleep Disorders. Neurotherapeutics 2021; 18:217-227. [PMID: 33580483 PMCID: PMC8116407 DOI: 10.1007/s13311-021-01013-w] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2021] [Indexed: 12/19/2022] Open
Abstract
The recent trend for legalization of medicinal cannabis and cannabinoid-containing products, together with their soporific effects, has led to a surge of interest of their potential therapeutic role in the management of some common sleep disorders, such as insomnia, sleep disordered breathing, and restless legs syndrome, and less common disorders such as narcolepsy and parasomnias. Although much of the pre-clinical and clinical data were derived from studies with relatively small sample sizes and limited by biases in assessment, and in clinical trials lack of allocation concealment, as a whole, the results indicate a potential therapeutic role for cannabinoids in the management of some sleep disorders. Clinical trials are underway for insomnia and obstructive sleep apnea management, but there remains a substantial need for rigorous large multi-center studies to assess the dose, efficacy, and safety of the various types of cannabinoids on sleep disorders. This review aims to summarize the modulatory effects of cannabinoids on sleep physiology and provide a critical evaluation of the research on their potential therapeutic benefit in various sleep disorders.
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Affiliation(s)
- Malvika Kaul
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, 909 S Wolcott Ave, Room 3135 (MC 719), Chicago, IL, 60612, USA
| | - Phyllis C Zee
- Department of Neurology, Center for Circadian and Sleep Medicine, Northwestern University Feinberg School of Medicine, 305 E. Chicago Ave., Chicago, IL, 60611, USA
| | - Ashima S Sahni
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, 909 S Wolcott Ave, Room 3135 (MC 719), Chicago, IL, 60612, USA.
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Kumar N, Gupta R, Kumar H, Mehta S, Rajan R, Kumar D, Kandadai RM, Desai S, Wadia P, Basu P, Mondal B, Juneja S, Rawat A, Meka SS, Mishal B, Prashanth LK, Srivastava AK, Goyal V. Impact of home confinement during COVID-19 pandemic on sleep parameters in Parkinson's disease. Sleep Med 2020; 77:15-22. [PMID: 33302094 PMCID: PMC7682933 DOI: 10.1016/j.sleep.2020.11.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/12/2020] [Accepted: 11/18/2020] [Indexed: 01/23/2023]
Abstract
Background Literature shows that home confinement during coronavirus disease 2019 (COVID-19) pandemic has significantly affected sleep. However, such information regarding subjects having Parkinson's disease (PD) is unavailable. Methods This cross-sectional study was conducted using a questionnaire, developed and validated by experts. PD subjects from nine centers across India were included. Questionnaire assessed presence as well as change in sleep-related parameters and PD symptoms during home confinement. Restless legs syndrome (RLS) and REM sleep behavior disorder (REMBD) was diagnosed using validated questionnaire. Additionally, changes in physical activity, adoption of new hobbies during home confinement and perceived quality of life were assessed. Results Of 832 subjects, 35.4% reported sleep disturbances. New-onset/worsening of sleep disturbances (NOWS) was reported by 23.9% subjects. Among those with sleep disturbances (n = 295), insomnia symptoms worsened in half (51.5%) and nearly one-fourth reported worsening of RLS (24.7%) and REMBD (22.7%) each. NOWS was common in subjects lacking adequate family support during home confinement (P = 0.03); home confinement > 60 days (P = 0.05) and duration of PD > 7 years (P = 0.008). Contrarily, physical activity >1 h/day and engagement in new hobbies during home confinement were associated with better sleep. NOWS was associated with worsening of motor as well as non-motor symptoms of PD (P < 0.001) and poorer life quality (P < 0.001). Conclusion Home confinement during COVID-19 pandemic was significantly associated with NOWS among PD subjects. NOWS was associated with global worsening of PD symptoms and poorer life quality. Physical activity >1 h/day and adoption of new hobbies during home confinement were associated with better sleep.
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Affiliation(s)
- Niraj Kumar
- Dept. of Neurology and Division of Sleep Medicine, All India Institute of Medical Sciences, Rishikesh, India.
| | - Ravi Gupta
- Dept. of Psychiatry and Division of Sleep Medicine, All India Institute of Medical Sciences, Rishikesh, India
| | | | - Sahil Mehta
- Dept. of Neurology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Roopa Rajan
- Dept. of Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - Deva Kumar
- Center for Parkinson's Disease and Movement Disorders, Vikram Hospital, Bengaluru, India
| | | | - Soaham Desai
- Dept. of Neurology, Shree Krishna Hospital, Karamsad, Anand, India
| | | | - Purba Basu
- Dept. of Neurology, Institute of Neurosciences, Kolkata, India
| | | | - Sanchita Juneja
- Dept. of Neurology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Ankita Rawat
- Dept. of Neurology and Division of Sleep Medicine, All India Institute of Medical Sciences, Rishikesh, India
| | | | | | - L K Prashanth
- Center for Parkinson's Disease and Movement Disorders, Vikram Hospital, Bengaluru, India
| | | | - Vinay Goyal
- Dept. of Neurology, Medanta Hospital, Gurugram, India
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Tuovinen N, Stefani A, Mitterling T, Heidbreder A, Frauscher B, Gizewski ER, Poewe W, Högl B, Scherfler C. Functional connectivity and topology in patients with restless legs syndrome: a case-control resting-state functional magnetic resonance imaging study. Eur J Neurol 2020; 28:448-458. [PMID: 33032390 PMCID: PMC7820983 DOI: 10.1111/ene.14577] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/29/2020] [Accepted: 10/05/2020] [Indexed: 02/05/2023]
Abstract
Background and purpose Functional connectivity studies revealed alterations within thalamic, salience, and default mode networks in restless legs syndrome patients. Methods Eighty‐two patients with restless legs syndrome (untreated, n = 30; on dopaminergic medication, n = 42; on alpha‐2‐delta ligands as mono‐ or polytherapy combined with dopaminergic medication, n = 10), and 82 individually age‐ and gender‐matched healthy controls were studied with resting‐state functional magnetic resonance imaging. Connectivity of 12 resting‐state networks was investigated with independent component analysis, and network topology was studied with graph methods among 410 brain regions. Results Patients with restless legs syndrome showed significantly higher connectivity within salience (p = 0.029), executive (p = 0.001), and cerebellar (p = 0.041) networks, as well as significantly lower (p < 0.05) cerebello‐frontal communication compared to controls. In addition, they had a significantly higher (p < 0.05) clustering coefficient and local efficiency in motor and frontal regions; lower clustering coefficient in the central sulcus; and lower local efficiency in the central opercular cortex, temporal, parieto‐occipital, cuneus, and occipital regions compared to controls. Untreated patients had significantly lower (p < 0.05) cerebello‐parietal communication compared to healthy controls. Connectivity between the thalamus and frontal regions was significantly increased (p < 0.05) in patients on dopaminergic medication compared to untreated patients and controls. Conclusions Networks with higher intranetwork connectivity (i.e., salience, executive, cerebellar) and lower cerebello‐frontal connectivity in the restless legs syndrome patients, as well as lower cerebello‐parietal connectivity in untreated patients, correspond to regions associated with attention, response inhibitory control, and processing of sensory information. Intact cerebello‐parietal communication and increased thalamic connectivity to the prefrontal regions in patients on dopaminergic medication suggests a treatment effect on thalamus.
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Affiliation(s)
- N Tuovinen
- Department of Psychiatry, Psychotherapy and Psychosomatics, Division of Psychiatry I, Medical University of Innsbruck, Innsbruck, Austria.,Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - A Stefani
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - T Mitterling
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.,Neurologie 1, Kepler Universitätsklinikum GmbH, Neuromed Campus, Linz, Austria.,Johannes Kepler University, Linz, Austria
| | - A Heidbreder
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.,Department of Neurology, University Hospital Münster, Münster, Germany
| | - B Frauscher
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.,Analytical Neurophysiology Lab, Montreal Neurological Institute & Hospital, McGill University, Montreal, Quebec, Canada
| | - E R Gizewski
- Neuroimaging Research Core Facility, Medical University of Innsbruck, Innsbruck, Austria.,Department of Neuroradiology, Medical University of Innsbruck, Innsbruck, Austria
| | - W Poewe
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - B Högl
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - C Scherfler
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.,Neuroimaging Research Core Facility, Medical University of Innsbruck, Innsbruck, Austria
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Chen LH, Shi JY, Zou TX, Zhang L, Gou Y, Lin Y, Chen HJ. Disturbance of thalamic metabolism and its association with regional neural dysfunction and cognitive impairment in minimal hepatic encephalopathy. Eur J Radiol 2020; 131:109252. [PMID: 32949859 DOI: 10.1016/j.ejrad.2020.109252] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 06/12/2020] [Accepted: 08/10/2020] [Indexed: 12/20/2022]
Abstract
PURPOSE To conduct the first investigation on thalamic metabolic alterations in minimal hepatic encephalopathy (MHE) and elucidate their association with intrinsic neural activity change and cognitive dysfunction. METHODS Thirty-eight cirrhotic patients [18 with MHE, 20 without MHE (NHE)] and 21 healthy controls (HC) were included, all of whom underwent 1H-magnetic resonance spectroscopy, resting-state functional magnetic resonance imaging (fMRI), as well as cognitive assessment based on the Psychometric Hepatic Encephalopathy Score (PHES). Metabolite ratios in the thalamus were measured, including N-acetyl aspartate (NAA)/creatine (Cr), glutamate plus glutamine (Glx)/Cr, choline (Cho)/Cr, and myo-inositol (mI)/Cr. Intrinsic neural activity was evaluated based on frequency-specific amplitude of low-frequency fluctuations (ALFF) using fMRI signals. RESULTS MHE patients showed an increase in Glx/Cr and a decrease in Cho/Cr and mI/Cr, compared with HC. These changes were aggravated from NHE to MHE. Cho/Cr and mI/Cr were positively correlated with regional ALFF derived from the frequency-specific band (0.01-0.027 Hz) and PHES. Receiver operating characteristic curve analysis showed that Cho/Cr and mI/Cr measurements exhibited moderate discrimination ability between NHE and MHE. CONCLUSION Our findings provide evidence that MHE is associated with disturbed metabolism in the thalamus, which may contribute to the altered neural activity and underlie the mechanisms of cognitive impairments. MRS measurements in the thalamus could serve as the potential biomarker for diagnosing MHE among cirrhotic patients.
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Affiliation(s)
- Li-Hong Chen
- Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, 350001, China
| | - Jia-Yan Shi
- Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, 350001, China
| | - Tian-Xiu Zou
- Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, 350001, China
| | - Ling Zhang
- Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, 350001, China; Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Yaoping Gou
- Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Department of Electronic Science, Xiamen University, Xiamen, 361005, China
| | - Yanqin Lin
- Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Department of Electronic Science, Xiamen University, Xiamen, 361005, China.
| | - Hua-Jun Chen
- Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, 350001, China.
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Stehlik R, Ulfberg J. (Neuro)Inflammatory Component May Be a Common Factor in Chronic Widespread Pain and Restless Legs Syndrome. CURRENT SLEEP MEDICINE REPORTS 2020. [DOI: 10.1007/s40675-020-00180-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Abstract
Purpose of Review
Recent studies have linked fibromyalgia (nociplastic pain) and depression to neuroinflammation. Restless legs syndrome (RLS) is highly prevalent in CWP (chronic widespread pain) and FMS (fibromyalgia syndrome) as well as in depression. This review focuses on evidence in the relationship between CWP and RLS and possible common pathophysiological mechanisms.
Recent Findings
CWP is chronic pain spread over various locations of the body and is a cardinal sign of fibromyalgia. Poor sleep quality is a common symptom in fibromyalgia as well as high levels of fatigue, poor cognition, and other associated features which include depression, headache, and abdominal pain. Evidence for a bilateral relationship between pain and sleep deficit is robust. The latest research focus is not only on insomnia symptoms in chronic pain but also on other types of sleep disorders such as RLS which is characterized by complaints of an “urge to move” frequently associated with dysesthesias. These sensations can also have painful characteristics. Thus, there is a possible overlap between these two entities. The high prevalence of RLS (33–54%) in CWP has been shown in several studies. The pathophysiological mechanisms behind CWP and RLS are still not completely known, but there is a rising amount of evidence on proinflammatory and neuroinflammatory processes in CWP. In RLS, there are links to dopaminergic dysfunction and more generally to monoaminergic dysfunctional circuits, BID (brain iron deficiency), altered glutamatergic neurotransmission, and genetic traits. Depression is a common comorbidity as well in CWP as RLS, and proinflammatory mechanisms have also been demonstrated in this condition.
Summary
The association between CWP and RLS is shown to be high and the pathogenesis of both conditions is still not completely understood. Recent research is focusing on proinflammatory and neuroinflammatory processes, not uniquely emerging in fibromyalgia/CWP, but inflammatory features have been found in depression as well as in sleep deficit. Proinflammatory/neuroinflammatory processes may be an underlying, common factor in both CWP and RLS that future research should investigate further.
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Earley CJ, Allen RP, Jones BC, Unger EL. Developing a behavioral model of Restless Legs Syndrome utilizing mice with natural variances in ventral midbrain iron. Sleep Med 2020; 71:135-140. [PMID: 32044226 PMCID: PMC10598803 DOI: 10.1016/j.sleep.2019.12.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/25/2019] [Accepted: 12/13/2019] [Indexed: 01/26/2023]
Abstract
BACKGROUND The primary symptoms of Restless Legs Syndrome (RLS) are circadian-dependent, leading to increased activity or decreased rest, especially at night. The primary pathology in RLS is brain iron insufficiency despite normal systemic iron stores. Natural variances in brain and peripheral iron concentrations across recombinant inbred (RI) murine strains provide a biological model of RLS. The question is whether these RI mice strains show a behavioral analog to circadian-dependent clinical phenotype of RLS. METHODS The home cage activity of eight female RI strains was measured over a 72-h period. The ratio of the average activity in the last 2 h of the active period relative to that in the total 12-h active period (late active period activity ratio, LAPAR) was the primary outcome variable. The relation of average LAPAR scores to measures of ventral midbrain (VMB) iron was evaluated across strains in this study. RESULTS RI strain 40 (LAPAR = 1.28) and RI strain 21 (LAPAR = 1.02) were the only strains to show an increased activity in the last part of the active period. ANOVA showed the increased activity was significantly greater during the last 2 h compared to the preceding 10 h of the active phase only for the RI strain 40. Average LAPAR across the eight strains did not significantly correlate with the VMB iron content (r = -0.27, p < 0.10) but did correlate with changes in VMB iron with iron deficiency (r = 0.71, p < 0.05) and diurnal change in VMB iron (r = 0.65, p < 0.05). CONCLUSION The female RI strain 40 mice exhibited a distinct end-of-active-period behavior analogous to circadian-dependent clinical phenotype of RLS.
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Affiliation(s)
- Christopher J Earley
- Department of Neurology, The Johns Hopkins University School of Medicine, 5501 Hopkins Bayview Circle, Baltimore, MD, 21209, USA.
| | - Richard P Allen
- Department of Neurology, The Johns Hopkins University School of Medicine, 5501 Hopkins Bayview Circle, Baltimore, MD, 21209, USA
| | - Byron C Jones
- Department of Biobehavioral Health, The Pennsylvania State University, 219 Behavioral Health Building, University Park, PA, 16802, USA
| | - Erica L Unger
- Department of Nutritional Sciences, The Pennsylvania State University, 110 Chandlee Lab, University Park, PA, 16802, USA
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de Paiva JPQ, Magalhães SC, Moura LM, Sato JR, Amaro E, Sterr A, Schlaffke L, Eckeli AL, do Prado GF, Conforto AB. Sensorimotor white matter projections and disease severity in primary Restless Legs Syndrome/Willis-Ekbom disease: a multimodal DTI analysis. Sleep Med 2020; 73:106-116. [PMID: 32805477 DOI: 10.1016/j.sleep.2020.05.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/22/2020] [Accepted: 05/26/2020] [Indexed: 01/18/2023]
Abstract
BACKGROUND Restless Legs Syndrome, a potentially disabling sleep disorder, also known as Willis-Ekbom disease (RLS/WED), may be caused by loss of inhibitory modulation of descending central motor pathways, structural changes in the somatosensory cortex, abnormal connectivity between motor and sensory areas, as well as by subtle abnormalities in white matter micro-organization. OBJECTIVE To compare diffusion-tensor imaging (DTI) metrics in areas associated with sensory or motor function, as well as sensorimotor integration, between subjects with primary mild-to-severe RLS/WED and controls. METHODS DTI metrics were assessed in 38 subjects with RLS/WED (14 mild to moderate, 24 severe to very severe) and 24 healthy age-matched controls with whole-brain Tract Based Spatial Statistics (TBSS), Region-of-interest (ROI) and probabilistic tractography based analyses. The ROIs corresponded to the corticospinal tract (CST) at the level of the cerebral peduncle; the superior, middle and inferior cerebellar peduncles. Subgroup analyses were made according to the severity of RLS/WED symptoms. The corticospinal tract was evaluated with probabilistic tractography. We also explored associations between significant findings and severity of symptoms with the Spearman's correlation coefficient. RESULTS TBSS analysis revealed decreased axial diffusivity (AD) in the left posterior thalamic radiation in RLS/WED. In subjects with severe RLS/WED, AD was reduced in the left posterior corona radiata and this reduction was negatively correlated with severity of symptoms. ROI-based analysis showed that radial diffusivity (RD) was increased in the superior cerebellar peduncles of individuals with severe RLS/WED. Tractography did not show between-group or subgroup differences. CONCLUSIONS Our results are consistent with subtle white matter changes, prominently in RLS/WED subjects with more severe symptoms, in areas related to sensory or motor function, as well as to sensorimotor integration, compared to controls. These findings support the hypothesis, raised by prior pathophysiological studies, of defective integration within these networks.
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Affiliation(s)
- Joselisa Péres Queiroz de Paiva
- Brain Institute, Hospital Israelita Albert Einstein (HIAE), São Paulo, SP, Brazil; Imaging Research Center, Hospital Israelita Albert Einstein (HIAE), São Paulo, SP, Brazil.
| | - Samir Câmara Magalhães
- Brain Institute, Hospital Israelita Albert Einstein (HIAE), São Paulo, SP, Brazil; Universidade de Fortaleza (UNIFOR), Unifor, Fortaleza, CE, Brazil
| | - Luciana Monteiro Moura
- Imaging Research Center, Hospital Israelita Albert Einstein (HIAE), São Paulo, SP, Brazil
| | - João Ricardo Sato
- Center for Mathematics, Computing and Cognition, Universidade Federal do ABC (UFABC), São Bernardo do Campo, SP, Brazil
| | - Edson Amaro
- Brain Institute, Hospital Israelita Albert Einstein (HIAE), São Paulo, SP, Brazil; Imaging Research Center, Hospital Israelita Albert Einstein (HIAE), São Paulo, SP, Brazil; Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil
| | - Annette Sterr
- School of Psychology, University of Surrey, Guildford, UK
| | - Lara Schlaffke
- Department of Neurology, BG University Clinic Bergmannsheil, Ruhr-University Bochum, Bochum, Germany
| | - Alan Luiz Eckeli
- Department of Neurosciences and Behavioral Sciences, Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | - Adriana Bastos Conforto
- Brain Institute, Hospital Israelita Albert Einstein (HIAE), São Paulo, SP, Brazil; Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil
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Lyu S, Xing H, DeAndrade MP, Perez PD, Yokoi F, Febo M, Walters AS, Li Y. The Role of BTBD9 in the Cerebellum, Sleep-like Behaviors and the Restless Legs Syndrome. Neuroscience 2020; 440:85-96. [PMID: 32446853 DOI: 10.1016/j.neuroscience.2020.05.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 04/27/2020] [Accepted: 05/14/2020] [Indexed: 12/28/2022]
Abstract
Recent genome-wide association studies (GWAS) have found cerebellum as a top hit for sleep regulation. Restless legs syndrome (RLS) is a sleep-related sensorimotor disorder characterized by uncomfortable sensations in the extremities, generally at night, which are often relieved by movements. Clinical studies have found that RLS patients have structural and functional abnormalities in the cerebellum. However, whether and how cerebellar pathology contributes to sleep regulation and RLS is not known. GWAS identified polymorphisms in BTBD9 conferring a higher risk of sleep disruption and RLS. Knockout of the BTBD9 homolog in mice (Btbd9) and fly results in motor restlessness and sleep disruption. We performed manganese-enhanced magnetic resonance imaging on the Btbd9 knockout mice and found decreased neural activities in the cerebellum, especially in lobules VIII, X, and the deep cerebellar nuclei. Electrophysiological recording of Purkinje cells (PCs) from Btbd9 knockout mice revealed an increased number of non-tonic PCs. Tonic PCs showed increased spontaneous activity and intrinsic excitability. To further investigate the cerebellar contribution to RLS and sleep-like behaviors, we generated PC-specific Btbd9 knockout mice (Btbd9 pKO) and performed behavioral studies. Btbd9 pKO mice showed significant motor restlessness during the rest phase but not in the active phase. Btbd9 pKO mice also had an increased probability of waking at rest. Unlike the Btbd9 knockout mice, there was no increased thermal sensation in the Btbd9 pKO. Our results indicate that the Btbd9 knockout influences the PC activity; dysfunction in the cerebellum may contribute to the motor restlessness found in the Btbd9 knockout mice.
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Affiliation(s)
- Shangru Lyu
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Hong Xing
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Mark P DeAndrade
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Pablo D Perez
- Department of Psychiatry, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Fumiaki Yokoi
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Marcelo Febo
- Department of Psychiatry, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Arthur S Walters
- Division of Sleep Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Yuqing Li
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA.
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Romero-Peralta S, Cano-Pumarega I, García-Borreguero D. Emerging Concepts of the Pathophysiology and Adverse Outcomes of Restless Legs Syndrome. Chest 2020; 158:1218-1229. [PMID: 32247713 DOI: 10.1016/j.chest.2020.03.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 02/15/2020] [Accepted: 03/13/2020] [Indexed: 01/05/2023] Open
Abstract
Restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED), is a common neurological disorder affecting up to 5% to 10% of the population, but it remains an underdiagnosed condition. RLS/WED is characterized by uncomfortable sensations, mainly in the legs, which appear during inactivity and worsen in the evening or at night. The prevalence of RLS/WED and periodic leg movements (PLMs) is increased in patients with sleep-disordered breathing, particularly in those with OSA, the most common sleep disorder encountered in sleep centers. New advances in the pathophysiology of RLS/WED have shown important implications for various genetic markers, neurotransmitter dysfunction, and iron deficiency. A practical approach to RLS/WED management includes an accurate diagnosis, the identification of reversible contributing factors, and the use of nonpharmacological therapies, including iron substitution (oral or IV) therapy. Many pharmacological agents are effective for the treatment of RLS/WED. Until recently, the first-line treatment of RLS/WED consisted of low-dose dopamine agonists (DA). However, given the fact that DAs cause high rates of augmentation of symptoms, international guidelines recommend that whenever possible the initial treatment of choice should be an α2δ ligand, and avoidance of dopaminergic agents unless absolutely necessary. If necessary, the lowest effective dose should be used for only the shortest possible time. The symptoms of RLS/WED can disrupt the quality of sleep as well as the quality of life. IV iron therapy may be considered in patients with refractory RLS. A better understanding of RLS/WED pathophysiology will allow patients to receive tailored therapy, resulting in an improved quality of life.
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Affiliation(s)
- Sofía Romero-Peralta
- Sleep Research Institute, Madrid; Sleep Unit, Respiratory Department, Hospital Universitario Guadalajara, Guadalajara
| | - Irene Cano-Pumarega
- Sleep Research Institute, Madrid; Sleep Unit, Respiratory Department, Hospital Universitario Ramón y, Madrid, Spain
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Thalamic GABA may modulate cognitive control in restless legs syndrome. Neurosci Lett 2019; 712:134494. [DOI: 10.1016/j.neulet.2019.134494] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 09/03/2019] [Accepted: 09/10/2019] [Indexed: 11/18/2022]
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Cha KS, Kim TJ, Jun JS, Byun JI, Sunwoo JS, Shin JW, Kim KH, Lee SK, Jung KY. Impaired slow oscillation, sleep spindle, and slow oscillation-spindle coordination in patients with idiopathic restless legs syndrome. Sleep Med 2019; 66:139-147. [PMID: 31877505 DOI: 10.1016/j.sleep.2019.09.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/10/2019] [Accepted: 09/16/2019] [Indexed: 10/25/2022]
Abstract
OBJECTIVES Thalamocortical abnormalities have been implicated in the pathophysiology of restless legs syndrome (RLS). We hypothesized that sleep spindle and slow oscillation (SO) activity is impaired in RLS, and that this dysfunction may contribute to sleep disturbance in these patients. To address this issue, we characterized sleep spindle and SO activity in RLS. METHODS Fifteen drug-naive, idiopathic RLS patients (13 female and 2 male) and 15 female healthy controls participated in this study. Nineteen-channel electroencephalograms were obtained during polysomnographic (PSG) recordings. An automated sleep spindle and SO detection algorithm was used to detect sleep spindle (12-16 Hz) and SO (<1 Hz) activity. The quantitative characteristics of sleep spindle and SO activity were investigated. RESULTS Compared with the healthy controls, in RLS patients, we observed density and power reduction in sleep spindles. In SOs, density reduction and duration increment were shown in RLS patients. In addition, SO-spindle coordination was deficient in RLS as revealed by reduced SO locked spindle power, dispersed and delayed spindle phase, and decreased SO-spindle coupling. Although sleep spindle power was negatively correlated with wake after sleep onset (WASO) time, SO duration was positively correlated with the arousal index in RLS. CONCLUSIONS Our study suggests that sleep disturbances may be mediated by a combined deficit in spindle and SO activity and SO-spindle coordination. The abnormal SO and spindle activity observed in RLS support the notion that thalamocortical abnormalities underlie this condition and may promote disturbed sleep integrity.
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Affiliation(s)
- Kwang Su Cha
- Department of Neurology, Seoul National University Hospital, Seoul, South Korea
| | - Tae-Joon Kim
- Department of Neurology, Seoul National University Hospital, Seoul, South Korea; Department of Neurology, Ajou University School of Medicine, Suwon, South Korea
| | - Jin-Sun Jun
- Department of Neurology, Hallym University College of Medicine, Seoul, South Korea
| | - Jung-Ick Byun
- Department of Neurology, Kyung Hee University Hospital at Gangdong, Seoul, South Korea
| | - Jun-Sang Sunwoo
- Department of Neurosurgery, Seoul National University Hospital, Seoul, South Korea
| | - Jung-Won Shin
- Department of Neurology, CHA Bundang Medical Center, CHA University, Seongnam, South Korea
| | - Kyung Hwan Kim
- Department of Biomedical Engineering, College of Health Science, Yonsei University, Wonju, South Korea
| | - Sang Kun Lee
- Department of Neurology, Seoul National University Hospital, Seoul, South Korea; Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Ki-Young Jung
- Department of Neurology, Seoul National University Hospital, Seoul, South Korea; Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea.
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Lehmann M, Hock A, Zoelch N, Landolt HP, Seifritz E. Dynamic Metabolic Changes in the Human Thalamus at the Transition From Waking to Sleep - Insights From Simultaneous Functional MR Spectroscopy and Polysomnography. Front Neurosci 2019; 13:1158. [PMID: 31736694 PMCID: PMC6833480 DOI: 10.3389/fnins.2019.01158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 10/14/2019] [Indexed: 11/13/2022] Open
Abstract
An important contribution of the thalamus to the transition from wakefulness to sleep is a consistent finding in animal studies. In humans, only little is currently known about the specific role of the thalamus in regulating wake-sleep transitions. Although changes in thalamic blood flow and activity have been reported, the underlying molecular mechanisms have not been investigated. Knowledge about neurotransmitter changes at the wake-to-sleep transition would be indispensable for a better translation of basic animal research findings to humans. Here, we start to fill this important scientific gap. More specifically, we benefit from recent advances in magnetic resonance (MR) spectroscopy, which allow for the non-invasive, local-specific and high-quality detection of naturally occurring metabolite changes in the human brain. We demonstrate in nine young adults able to produce consolidated sleep in the MR spectroscopy scanner, a specific decrease in thalamic glutamate concentration from wakefulness to stage N2 sleep. The magnitude of this decrease was highly correlated with individual N2 sleep duration. When five participants of the original experiment were kept awake in a separate control condition, no decrease in thalamic glutamate levels occurred. The study highlights for the first time in humans that dynamic changes in distinct brain metabolites can be reliably detected at the transition from waking to sleep. The reported methodology to simultaneously acquire functional MR spectroscopy data and neurophysiological signals offers great potential for investigating the molecular mechanisms underlying the transition between and the maintenance of sleep and wake states in humans.
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Affiliation(s)
- Mick Lehmann
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Sleep & Health Zurich, University of Zurich, Zurich, Switzerland
- Department of Psychiatry, Psychotherapy and Psychosomatics, Hospital of Psychiatry, University of Zurich, Zurich, Switzerland
| | - Andreas Hock
- Department of Psychiatry, Psychotherapy and Psychosomatics, Hospital of Psychiatry, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Niklaus Zoelch
- Department of Psychiatry, Psychotherapy and Psychosomatics, Hospital of Psychiatry, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
- Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland
| | - Hans-Peter Landolt
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Sleep & Health Zurich, University of Zurich, Zurich, Switzerland
| | - Erich Seifritz
- Sleep & Health Zurich, University of Zurich, Zurich, Switzerland
- Department of Psychiatry, Psychotherapy and Psychosomatics, Hospital of Psychiatry, University of Zurich, Zurich, Switzerland
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48
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Lyu S, DeAndrade MP, Mueller S, Oksche A, Walters AS, Li Y. Hyperactivity, dopaminergic abnormalities, iron deficiency and anemia in an in vivo opioid receptors knockout mouse: Implications for the restless legs syndrome. Behav Brain Res 2019; 374:112123. [PMID: 31376441 DOI: 10.1016/j.bbr.2019.112123] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/24/2019] [Accepted: 07/30/2019] [Indexed: 12/13/2022]
Abstract
Previous studies have uncovered a potential role of the opioid system in iron hemostasis and dopamine metabolism. Abnormalities in both of these systems have been noted in human RLS. Autopsy studies of human RLS have shown an endogenous opioid deficiency in the thalamus. Opioids, particularly prolonged-release oxycodone/naloxone, have been approved in Europe to be a second-line therapy for severe restless legs syndrome (RLS). To study the role of opioid receptors in the pathogenesis of RLS, we used a triple knockout (KO) mouse strain that lack mu, delta, and kappa opioid receptors and explored the behavioral and biochemical parameters relevant to RLS. The triple KO mice showed hyperactivity and a trend of increased probability of waking during the rest period (day) akin to that in human RLS (night). Surprisingly, triple KO mice also exhibit decreased serum iron concentration, evidence of anemia, a significant dysfunction in dopamine metabolism akin to that noted in human RLS, as well as an increased latency in response to thermal stimuli. To our knowledge, this is the first study to demonstrate that the endogenous opioid system may play a role in iron metabolism and subsequently in the pathogenesis of anemia. It is also the first study showing that opioid receptors are involved in the production of motor restlessness with a circadian predominance. Our findings support the role of endogenous opioids in the pathogenesis of RLS, and the triple KO mice can be used to understand the relationship between iron deficiency, anemia, dopaminergic dysfunction, and RLS.
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Affiliation(s)
- Shangru Lyu
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Mark P DeAndrade
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Stefan Mueller
- Mundipharma Research GmbH & Co. KG, Höhenstraße 10, Limburg, Germany
| | - Alexander Oksche
- Mundipharma Research Limited, Cambridge, UK; Rudolf-Buchheim-Institut für Pharmakologie, University of Giessen, Giessen, Germany
| | - Arthur S Walters
- Division of Sleep Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Yuqing Li
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA.
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Chiaro G, Manconi M. Restless legs syndrome, periodic limb movements during sleep and cardiovascular risk. Auton Neurosci 2019; 220:102554. [PMID: 31331694 DOI: 10.1016/j.autneu.2019.102554] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 05/20/2019] [Accepted: 05/28/2019] [Indexed: 12/16/2022]
Abstract
Multiple mechanisms may modulate an association between restless legs syndrome/Willis-Ekbom disease (RLS/WED) and cardiovascular disease (CVD), including chronic sleep deprivation, intermittent, periodic limb movements in sleep (PLMS)-related autonomic fluctuations and possible autonomic dysfunction intrinsically associated with RLS per se. The purpose of this paper is to review the existing RLS/WED literature focusing on the pathophysiologic evidence for possible associations between RLS/WED and PLMS with CVD and events (CVE). Specific intrinsic dysautonomic aspects of the disease, which may contribute to generating CVD, are separately discussed. The association between RLS/WED and both CV risk factors and CVD still remains elusive. Although several shared pathophysiological causes could explain these possible relationships, the emerging body of literature focusing on these disorders remains controversial. Not only longitudinal population-based studies and meta-analyses, but also more animal models and therapeutic interventions are needed in order to build a sufficiently robust body of evidence on this topic.
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Affiliation(s)
- Giacomo Chiaro
- Sleep and Epilepsy Center, Neurocenter of Southern Switzerland, Civic Hospital of Lugano, Lugano, Switzerland; Department of Biomedical and Neuromotor Sciences, Bellaria Hospital, University of Bologna, Bologna, Italy
| | - Mauro Manconi
- Sleep and Epilepsy Center, Neurocenter of Southern Switzerland, Civic Hospital of Lugano, Lugano, Switzerland; Department of Neurology, Bern University Hospital, Bern, Switzerland.
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Restless legs syndrome: Clinical changes in nervous system excitability at the spinal cord level. Sleep Med Rev 2019; 47:9-17. [PMID: 31212170 DOI: 10.1016/j.smrv.2019.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/30/2019] [Accepted: 05/27/2019] [Indexed: 12/20/2022]
Abstract
Restless legs syndrome (RLS) is a complex multifactorial disorder whose aetiology has yet to be fully elucidated. Some of the features of RLS, such as processing of sensations and activation of movement, may result from a dysfunction in spinal processing giving rise to a state of spinal hyperexcitability. In the current article we review studies investigating spinal excitability in RLS patients looking specifically at electrophysiological studies of spinal activity, sensory evaluations, and spinal reflex studies. Increased spinal excitability has been shown in RLS patients based on the combined data from electrophysiological studies. Results from studies assessing sensory evaluations in RLS patients show enhanced spinal processing of nociceptive inputs possibly due to central sensitisation. However, not all sensory modalities demonstrate an increase in sensitivity. An increase in nervous system excitability would result in an increase in reflex responses in RLS patients however the data from reflex analyses in RLS patients has failed to consistently show this expected result. Overall changes to RLS spinal excitability have been demonstrated though these changes might be heterogeneous as not all afferent input appears to be affected in the same manner. There may be phase-dependent and modality-dependent alterations in spinal excitability suggesting that the theory of absolute spinal hyperexcitability in RLS patients' needs to be reconsidered.
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