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McWilliams S, Hill O, Ipsiroglu OS, Clemens S, Weber AM, Chen M, Connor J, Felt BT, Manconi M, Mattman A, Silvestri R, Simakajornboon N, Smith SM, Stockler S. Iron Deficiency and Sleep/Wake Behaviors: A Scoping Review of Clinical Practice Guidelines-How to Overcome the Current Conundrum? Nutrients 2024; 16:2559. [PMID: 39125438 PMCID: PMC11314179 DOI: 10.3390/nu16152559] [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: 06/25/2024] [Revised: 07/28/2024] [Accepted: 07/29/2024] [Indexed: 08/12/2024] Open
Abstract
Current evidence suggests that iron deficiency (ID) plays a key role in the pathogenesis of conditions presenting with restlessness such as attention deficit hyperactivity disorder (ADHD) and restless legs syndrome (RLS). In clinical practice, ID and iron supplementation are not routinely considered in the diagnostic work-up and/or as a treatment option in such conditions. Therefore, we conducted a scoping literature review of ID guidelines. Of the 58 guidelines included, only 9 included RLS, and 3 included ADHD. Ferritin was the most frequently cited biomarker, though cutoff values varied between guidelines and depending on additional factors such as age, sex, and comorbidities. Recommendations surrounding measurable iron biomarkers and cutoff values varied between guidelines; moreover, despite capturing the role of inflammation as a concept, most guidelines often did not include recommendations for how to assess this. This lack of harmonization on the interpretation of iron and inflammation biomarkers raises questions about the applicability of current guidelines in clinical practice. Further, the majority of ID guidelines in this review did not include the ID-associated disorders, ADHD and RLS. As ID can be associated with altered movement patterns, a novel consensus is needed for investigating and interpreting iron status in the context of different clinical phenotypes.
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Affiliation(s)
- Scout McWilliams
- H-Behaviours Research Lab (Previously Sleep/Wake-Behaviours Research Lab), BC Children’s Hospital Research Institute, Department of Pediatrics, University of British Columbia, Vancouver, BC V5Z 4H4, Canada; (S.M.); (O.H.); (S.S.)
| | - Olivia Hill
- H-Behaviours Research Lab (Previously Sleep/Wake-Behaviours Research Lab), BC Children’s Hospital Research Institute, Department of Pediatrics, University of British Columbia, Vancouver, BC V5Z 4H4, Canada; (S.M.); (O.H.); (S.S.)
| | - Osman S. Ipsiroglu
- H-Behaviours Research Lab (Previously Sleep/Wake-Behaviours Research Lab), BC Children’s Hospital Research Institute, Department of Pediatrics, University of British Columbia, Vancouver, BC V5Z 4H4, Canada; (S.M.); (O.H.); (S.S.)
- Divisions of Developmental Pediatrics, Child and Adolescent Psychiatry and Respirology, BC Children’s Hospital, Department of Pediatrics, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Stefan Clemens
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA;
| | - Alexander Mark Weber
- Department of Pediatrics, University of British Columbia, Vancouver, BC V6T 1Z4, Canada;
- BC Children’s Hospital Research Institute, Vancouver, BC V5Z 4H4, Canada
| | - Michael Chen
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (M.C.); (A.M.)
| | - James Connor
- Department of Neurosurgery, Penn State Hershey Medical Center, Hershey, PA 17033, USA;
| | - Barbara T. Felt
- Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Mauro Manconi
- Sleep Medicine Unit, Neurocenter of the Southern Switzerland, Regional Hospital of Lugano, Faculty of Biomedical Sciences, Università della Svizzera Italiana, 6900 Lugano, Switzerland;
- Department of Neurology, University of Bern, 3012 Bern, Switzerland
| | - Andre Mattman
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (M.C.); (A.M.)
| | - Rosalia Silvestri
- Department of Clinical and Experimental Medicine, Sleep Medicine Center, University of Messina, Azienda Ospedaliera Universitaria “Gaetano Martino”, 98122 Messina, Italy;
| | - Narong Simakajornboon
- Sleep Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA;
| | - Susan M. Smith
- Department of Nutrition, UNC-Nutrition Research Institute, University of North Carolina at Chapel Hill, Kannapolis, NC 28081, USA;
| | - Sylvia Stockler
- H-Behaviours Research Lab (Previously Sleep/Wake-Behaviours Research Lab), BC Children’s Hospital Research Institute, Department of Pediatrics, University of British Columbia, Vancouver, BC V5Z 4H4, Canada; (S.M.); (O.H.); (S.S.)
- Department of Pediatrics, University of British Columbia, Vancouver, BC V6T 1Z4, Canada;
- Division of Biochemical Diseases, Department of Pediatrics, BC Children’s Hospital, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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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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Zhang J, Zhang J, Sun H, Yang J, Ma Y, Chen K, Su J, Yu X, Yang F, Zhang Z, Zhao T, Hu X, Zhai Y, Liu Q, Wang J, Liu C, Wang Z. Cerebellum drives functional dysfunctions in restless leg syndrome. Sleep Med 2023; 110:172-178. [PMID: 37595434 DOI: 10.1016/j.sleep.2023.08.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 07/04/2023] [Accepted: 08/14/2023] [Indexed: 08/20/2023]
Abstract
OBJECTIVE Restless legs syndrome (RLS) has serious effects on patients' sleep quality, physical and mental health. However, the pathophysiological mechanisms of RLS remain unclear. This study utilized both static and dynamic functional activity and connectivity analyses approaches as well as effective connectivity analysis to reveal the neurophysiological basis of RLS. METHODS The resting-state functional MRI (rs-fMRI) data from 32 patients with RLS and 33 age-, and gender-matched healthy control (HC) were collected. Dynamic and static amplitude of low frequency fluctuation (ALFF), functional connectivity (FC), and Granger causality analysis (GCA) were employed to reveal the abnormal functional activities and couplings in patients with RLS. RESULTS RLS patients showed over-activities in left parahippocampus and right cerebellum, hyper-connectivities of right cerebellum with left basal ganglia, left postcentral gyrus and right precentral gyrus, and enhanced effective connectivity from right cerebellum to left postcentral gyrus compared to HC. CONCLUSIONS Abnormal cerebellum-basal ganglia-sensorimotor cortex circuit may be the underlying neuropathological basis of RLS. Our findings highlight the important role of right cerebellum in the onset of RLS and suggest right cerebellum may be a potential target for precision therapy.
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Affiliation(s)
- Jiang Zhang
- College of Electrical Engineering, Sichuan University, Chengdu, China; Med-X Center for Informatics, Sichuan University, Chengdu, China
| | - Jingyue Zhang
- College of Electrical Engineering, Sichuan University, Chengdu, China
| | - Hui Sun
- College of Electrical Engineering, Sichuan University, Chengdu, China
| | - Jia Yang
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, China; Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan, China
| | - Yingzi Ma
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, China; Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan, China
| | - Kexuan Chen
- Medical School, Kunming University of Science and Technology, Kunming, China
| | - Jing Su
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, China; Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan, China
| | - Xiaohui Yu
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, China; Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan, China
| | - Futing Yang
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, China; Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan, China
| | - Zhiwei Zhang
- College of Electrical Engineering, Sichuan University, Chengdu, China
| | - Tianyu Zhao
- College of Electrical Engineering, Sichuan University, Chengdu, China
| | - Xiuying Hu
- Med-X Center for Informatics, Sichuan University, Chengdu, China; Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, China
| | - Yiran Zhai
- College of Electrical Engineering, Sichuan University, Chengdu, China; Med-X Center for Informatics, Sichuan University, Chengdu, China
| | - Qihong Liu
- College of Biomedical Engineering, Sichuan University, Chengdu, China
| | - Jiaojian Wang
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, China; Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan, China.
| | - Chunyan Liu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China; Beijing Key Laboratory of Neuromodulation, Beijing, China.
| | - Zhengbo Wang
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, China; Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan, China.
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Antelmi E, Squintani GM, Sandri A, Lippolis M, Segatti A, Tinazzi M. Defect of the Endogenous Inhibitory Pain System in Idiopathic Restless Legs Syndrome: A Laser Evoked Potentials Study. Mov Disord 2023; 38:1688-1696. [PMID: 37314385 DOI: 10.1002/mds.29509] [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: 03/20/2023] [Revised: 05/24/2023] [Accepted: 05/30/2023] [Indexed: 06/15/2023] Open
Abstract
BACKGROUND Restless legs syndrome (RLS) is a complex sensorimotor disorder. Symptoms worsen toward evening and at rest and are temporarily relieved by movement. Symptoms are perceived as painful in up to 45% of cases, and nociception system may be involved. OBJECTIVES To assess the descending diffuse noxious inhibitory control in RLS patients. METHODS Twenty-one RLS patients and twenty age and sex-matched healthy controls (HC) underwent a conditioned pain modulation protocol. Cutaneous heat stimuli were delivered via laser evoked potentials (LEPs) on the dorsum of the right hand (UL) and foot (LL). N2 and P2 latencies, N2/P2 amplitude and pain ratings (NRS) were recorded before (baseline), during, and after a heterotopic noxious conditioning stimulation (HNCS) application. The baseline/HNCS ratio was calculated for both UL and LL. RESULTS N2 and P2 latencies did not vary between groups at each condition and limbs. Both groups showed a physiological N2/P2 amplitude and NRS reduction during the HNCS condition in UL and LL in comparison to baseline and post conditions (all, P < 0.003). Between-groups comparisons revealed a significant lower amplitude reduction in RLS at the N2/P2 amplitude during the HNCS condition only for LL (RLS, 13.6 μV; HC, 10.1 μV; P = 0.004). Such result was confirmed by the significant difference at the ratio (RLS, 69%, HC, 52.5%; P = 0.038). CONCLUSIONS The lower physiological reduction during the HNCS condition at LL in RLS patients suggests a defect in the endogenous inhibitory pain system. Further studies should clarify the causal link of this finding, also investigating the circadian modulation of this paradigm. © 2023 International Parkinson and Movement Disorder Society.
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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, Verona, Italy
| | | | - Angela Sandri
- Neurology Unit, Parkinson Disease and Movement Disorders Division, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | | | - Alessia Segatti
- UOC Neurology A, Department of Neurosciences, AOUI, Verona, Italy
| | - Michele Tinazzi
- Neurology Unit, Parkinson Disease and Movement Disorders Division, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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Kim TJ, Kim MH, Kim JH, Jun JS, Byun JI, Sunwoo JS, Shin JW, Gho SM, Sohn CH, Jung KY. Change of iron content in brain regions after intravenous iron therapy in restless legs syndrome: quantitative susceptibility mapping study. Sleep 2023; 46:zsad154. [PMID: 37257418 DOI: 10.1093/sleep/zsad154] [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: 03/15/2023] [Revised: 05/22/2023] [Indexed: 06/02/2023] Open
Abstract
STUDY OBJECTIVES The pathomechanism of restless legs syndrome (RLS) is related to brain iron deficiency and iron therapy is effective for RLS; however, the effect of iron therapy on human brain iron state has never been studied with magnetic resonance imaging. This study aimed to investigate the change of brain iron concentrations in patients with RLS after intravenous iron therapy using quantitative susceptibility mapping (QSM). METHODS We enrolled 31 RLS patients and 20 healthy controls. All participants underwent initial baseline (t0) assessment using brain magnetic resonance imaging, serum iron status, and sleep questionnaires including international RLS Study Group rating scale (IRLS). RLS patients underwent follow-up tests at 6 and 24 weeks (t1 and t2) after receiving 1000 mg ferric carboxymaltose. Iron content of region-of-interest on QSM images was measured for 13 neural substrates using the fixed-shaped method. RESULTS RLS symptoms evaluated using IRLS were significantly improved after iron treatment (t0: 29.7 ± 6.5, t1: 19.5 ± 8.5, t2: 21.3 ± 10.1; p < .001). There was no significant difference in susceptibility values between the controls and RLS patients at t0. In the caudate nucleus, putamen, and pulvinar thalamus of RLS patients, the QSM values differed significantly for three timepoints (p = .035, .048, and .032, respectively). The post-hoc analysis revealed that the QSM values increased at t1 in the caudate nucleus (66.8 ± 18.0 vs 76.4 ± 16.6, p = .037) and decreased from t1 to t2 in the putamen (69.4 ± 16.3 vs 62.5 ± 13.6, p = .025). Changes in the QSM values for the pulvinar and caudate nuclei at t1 were positively and negatively correlated with symptomatic improvement, respectively (r = 0.361 and -0.466, respectively). CONCLUSIONS Intravenous iron treatment results in changes in brain iron content which correlate to reductions in RLS severity. This suggests a connection between symptom improvement and the associated specific brain regions constituting the sensorimotor network.
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Affiliation(s)
- Tae-Joon Kim
- Department of Neurology, Ajou University School of Medicine, Suwon, Republic of Korea
- Department of Neurology, Ajou University Hospital, Suwon, Republic of Korea
| | - Min Hye Kim
- Department of Neurology, Ajou University Hospital, Suwon, Republic of Korea
| | - Jung Hwan Kim
- Department of Neurology, Ajou University School of Medicine, Suwon, Republic of Korea
| | - Jin-Sun Jun
- Department of Neurology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Republic of Korea
| | - Jung-Ick Byun
- Department of Neurology, Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea
| | - Jun-Sang Sunwoo
- Department of Neurology, Kangbuk Samsung Hospital, Seoul, Republic of Korea
| | - Jung-Won Shin
- Department of Neurology, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea
| | - Sung-Min Gho
- MR Clinical Solutions & Research Collaborations, GE Healthcare, Seoul, Republic of Korea
| | - Chul-Ho Sohn
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea
| | - Ki-Young Jung
- Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
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McNamara S, Hon B, Kirshblum S. Restless leg syndrome in spinal cord injury: case report. Spinal Cord Ser Cases 2023; 9:19. [PMID: 37137889 PMCID: PMC10156660 DOI: 10.1038/s41394-023-00576-4] [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: 09/12/2022] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/05/2023] Open
Abstract
CASE DESCRIPTION Restless leg syndrome (RLS) is a condition infrequently reported in spinal cord injury that causes an uncomfortable sensation in the legs and an urge to move them. We report a case involving a 63-year-old man with incomplete paraplegia with an onset of RLS four years post injury. FINDINGS Based upon history, pramipexole was prescribed for the presumptive diagnosis of RLS, with good effect. Initial workup revealed an anemia (hemoglobin of 9.3 gram/deciliter (g/dl)) and iron deficiency (ferritin of 10 microgram/liter (μg/L)), necessitating further evaluation. CONCLUSION Due to the complexities in diagnosing RLS in patients with SCI, it is important to be cognizant of symptoms and to consider this diagnosis to initiate the appropriate work-up for an etiology, of which iron deficiency anemia is common.
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Affiliation(s)
- Shane McNamara
- Rutgers New Jersey Medical School, Department of Physical Medicine and Rehabilitation, Newark, NJ, USA.
| | - Beverly Hon
- Rutgers New Jersey Medical School, Department of Physical Medicine and Rehabilitation, Newark, NJ, USA
- Spinal Cord Injury & Disorders Department, Veteran Administration New Jersey Healthcare System, East Orange, NJ, USA
| | - Steven Kirshblum
- Rutgers New Jersey Medical School, Department of Physical Medicine and Rehabilitation, Newark, NJ, USA
- Kessler Institute for Rehabilitation, West Orange, New Jersey. Kessler Foundation, West Orange, NJ, USA
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Silvani A, Ghorayeb I, Manconi M, Li Y, Clemens S. Putative Animal Models of Restless Legs Syndrome: A Systematic Review and Evaluation of Their Face and Construct Validity. Neurotherapeutics 2023; 20:154-178. [PMID: 36536233 PMCID: PMC10119375 DOI: 10.1007/s13311-022-01334-4] [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] [Accepted: 12/02/2022] [Indexed: 12/24/2022] Open
Abstract
Restless legs syndrome (RLS) is a sensorimotor disorder that severely affects sleep. It is characterized by an urge to move the legs, which is often accompanied by periodic limb movements during sleep. RLS has a high prevalence in the population and is usually a life-long condition. While its origins remain unclear, RLS is initially highly responsive to treatment with dopaminergic agonists that target D2-like receptors, in particular D2 and D3, but the long-term response is often unsatisfactory. Over the years, several putative animal models for RLS have been developed, mainly based on the epidemiological and neurochemical link with iron deficiency, treatment efficacy of D2-like dopaminergic agonists, or genome-wide association studies that identified risk factors in the patient population. Here, we present the first systematic review of putative animal models of RLS, provide information about their face and construct validity, and report their role in deciphering the underlying pathophysiological mechanisms that may cause or contribute to RLS. We propose that identifying the causal links between genetic risk factors, altered organ functions, and changes to molecular pathways in neural circuitry will eventually lead to more effective new treatment options that bypass the side effects of the currently used therapeutics in RLS, especially for long-term therapy.
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Affiliation(s)
- Alessandro Silvani
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum - University of Bologna, Ravenna Campus, Ravenna, Italy
| | - Imad Ghorayeb
- Département de Neurophysiologie Clinique, Pôle Neurosciences Cliniques, CHU de Bordeaux, Bordeaux, France
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, UMR 5287, Université de Bordeaux, Bordeaux, France
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, UMR 5287, CNRS, Bordeaux, France
| | - Mauro Manconi
- Sleep Medicine Unit, Neurocenter of Southern Switzerland, EOC, Ospedale Civico, Lugano, Switzerland
- Department of Neurology, University Hospital, Inselspital, Bern, Switzerland
- Faculty of Biomedical Sciences, Università della Svizzera Italiana, Lugano, Switzerland
| | - Yuqing Li
- Department of Neurology, College of Medicine, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, USA
| | - Stefan Clemens
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, USA.
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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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9
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Kalampokini S, Poyiadjis S, Vavougios GD, Artemiadis A, Zis P, Hadjigeorgiou GM, Bargiotas P. Restless legs syndrome due to brainstem stroke: A systematic review. Acta Neurol Scand 2022; 146:440-447. [PMID: 36063288 DOI: 10.1111/ane.13702] [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: 06/29/2022] [Revised: 08/05/2022] [Accepted: 08/21/2022] [Indexed: 11/28/2022]
Abstract
Restless Legs Syndrome (RLS) is a sleep-related movement disorder, which can also result from brainstem pathology. A systematic review of articles published in the electronic databases PubMed and Web of Science was conducted to summarize the existent literature on RLS associated with a brainstem stroke. We identified eight articles including 19 subjects with RLS due to brainstem ischemic lesion. The symptoms occurred simultaneously with the infarction (66.7%) or few days after (33.3%). The most common location of infarction was pons and less commonly medulla. In most cases (68.4%), symptoms were unilateral. In the majority of those cases (92.3%), the contralateral limb was affected due to a lateral pons infarction. RLS symptoms after infarction improved or resolved in almost 90% of cases within a few days up to 3 months. In almost all patients who received dopaminergic treatment (11 out of 13, 91.7%), the symptoms improved significantly or resolved completely. Screening for RLS has to be considered in patients suffering a brainstem stroke, particularly anteromedial pontine infarction. The appearance of acute unilateral RLS symptoms, usually in association with other sensorimotor deficits, should prompt the clinician to consider a vascular event in the brainstem. RLS in these cases seem to have a favorable outcome and respond well to dopaminergic treatment.
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Affiliation(s)
- Stefania Kalampokini
- Department of Neurology, Nicosia General Hospital and Medical school, University of Cyprus, Nicosia, Cyprus
| | | | - George D Vavougios
- Department of Neurology, Nicosia General Hospital and Medical school, University of Cyprus, Nicosia, Cyprus
| | - Artemios Artemiadis
- Department of Neurology, Nicosia General Hospital and Medical school, University of Cyprus, Nicosia, Cyprus
| | - Panagiotis Zis
- Department of Neurology, Nicosia General Hospital and Medical school, University of Cyprus, Nicosia, Cyprus
| | - Georgios M Hadjigeorgiou
- Department of Neurology, Nicosia General Hospital and Medical school, University of Cyprus, Nicosia, Cyprus
| | - Panagiotis Bargiotas
- Department of Neurology, Nicosia General Hospital and Medical school, University of Cyprus, Nicosia, Cyprus
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Zang QL, Zheng JH, Ma JJ, Zhang Q, Huang PP, Shen NN, Miao W. Neuroanatomy and Functional Connectivity in Patients with Parkinson's Disease with or without Restless Legs Syndrome. Neurol Ther 2022; 11:1625-1636. [PMID: 35999489 DOI: 10.1007/s40120-022-00397-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 08/08/2022] [Indexed: 11/30/2022] Open
Abstract
INTRODUCTION Restless legs syndrome (RLS) is a common non-motor symptom in Parkinson's disease (PD), but its pathogenesis remains unclear. This study aimed to explore the potential neural substrates of RLS in a large sample of patients with PD. METHODS A total of 42 patients with PD with RLS and 124 patients with PD without RLS were prospectively recruited at our hospital between February 2019 and October 2020 and underwent structural and resting-state functional magnetic resonance imaging. Differences between the two patient groups were assessed using voxel-based morphometry and functional connectivity analysis. PD duration, Part III of the Movement Disorder Society's Unified Parkinson's Disease Rating Scale (MDS-UPDRS-III) score, and levodopa equivalent daily dose were treated as covariates. RESULTS Patients with PD with RLS had significantly larger gray matter volume in the bilateral posterior cingulate cortex than patients with PD without RLS (FDR-adjusted P < 0.05). Compared to patients without RLS, those with RLS had significantly lower functional connectivity between the left central opercular cortex and the bilateral precentral gyri and postcentral gyri (FDR-adjusted P < 0.001). CONCLUSION Our study provides the first evidence that in patients with PD, RLS is associated with significantly larger gray matter volume in the posterior cingulate cortex and lower resting-state functional connectivity within the sensorimotor network. Our results may help clarify the pathophysiology of RLS in PD and identify possible therapeutic targets.
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Affiliation(s)
- Qiu Ling Zang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, 1 Jian She East Road, Zhengzhou, 450007, Henan Province, People's Republic of China
| | - Jin Hua Zheng
- Department of Neurology, Henan Provincial People's Hospital, No. 7, Weiwu Road, Zhengzhou, 450003, Henan Province, People's Republic of China
| | - Jian Jun Ma
- Department of Neurology, Henan Provincial People's Hospital, No. 7, Weiwu Road, Zhengzhou, 450003, Henan Province, People's Republic of China.
| | - Qi Zhang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, 1 Jian She East Road, Zhengzhou, 450007, Henan Province, People's Republic of China
| | - Pei Pei Huang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, 1 Jian She East Road, Zhengzhou, 450007, Henan Province, People's Republic of China
| | - Nan Nan Shen
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, 1 Jian She East Road, Zhengzhou, 450007, Henan Province, People's Republic of China
| | - Wang Miao
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, 1 Jian She East Road, Zhengzhou, 450007, Henan Province, People's Republic of China.
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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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Mail Gurkan Z, Tantik Pak A, Nacar Dogan S, Sengul Y. Microstructural changes of basal ganglia in migraine with restless legs syndrome: findings from a neuroimaging study. Sleep Biol Rhythms 2022; 20:361-369. [PMID: 38469422 PMCID: PMC10899932 DOI: 10.1007/s41105-022-00376-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 02/01/2022] [Indexed: 01/18/2023]
Abstract
In this study, it is planned to investigate the integrity of the basal ganglia structures in migraineurs with restless legs syndrome (RLS) to explore this relationship. In this study, 58 patients who were diagnosed migraine and 51 healthy controls (HCs) were included. Patients diagnosed with migraine were divided into two groups: Group I (migraine without RLS) and Group II (migraine with RLS). The integrity of basal ganglia was evaluated with region of interest diffusion tensor imaging method which allows us to assess microstructural changes of the tissue. The mean age of the patients was 35.98 ± 7.92 years, and the mean age of the HCs was 33.84 ± 11.06. 84.5% (n = 49) of the patients were female and 15.5% (n = 9) were male. 82.4% (n = 42) of the HCs were female, 17.6% (n = 9) were male. The number of the patients without RLS was 41 (Group I), and the number of the patients with RLS was 17 (Group II). When basal ganglia structures were compared between groups of the patients with and without RLS, the fractional anisotropy (FA) value of the left putamen differed (Group I: 0.30 ± 0.06 vs. Group II: 0.25 ± 0.7, p = 0.01). The significant relationship was found attack frequency and presence of RLS with left putamen FA values according to multiple regression analysis. It was determined in this study that the changes in the microstructure of putamen, one of the basal ganglia structures, may be associated with the presence of RLS in migraineurs.
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Affiliation(s)
- Zahide Mail Gurkan
- Neurology Department of Gaziosmanpasa Training and Research Hospital, Gaziosmanpasa, Istanbul, Turkey
| | - Aygul Tantik Pak
- Neurology Department of Gaziosmanpasa Training and Research Hospital, Gaziosmanpasa, Istanbul, Turkey
| | - Sebahat Nacar Dogan
- Radiology Department of Gaziosmanpasa Training and Research Hospital, Gaziosmanpasa, Istanbul, Turkey
| | - Yıldızhan Sengul
- Neurology Department of Gaziosmanpasa Training and Research Hospital, Gaziosmanpasa, Istanbul, Turkey
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13
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Beliveau V, Stefani A, Birkl C, Kremser C, Gizewski ER, Högl B, Scherfler C. Revisiting brain iron deficiency in restless legs syndrome using magnetic resonance imaging. Neuroimage Clin 2022; 34:103024. [PMID: 35500370 PMCID: PMC9065426 DOI: 10.1016/j.nicl.2022.103024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 04/07/2022] [Accepted: 04/24/2022] [Indexed: 12/19/2022]
Abstract
Increased iron in RLS was found in the caudate, putamen and red nucleus. A meta-analysis revealed no significant evidence of reduced iron in RLS as assessed by MRI. Evidence suggestive of publication bias for results on the substantia nigra was found. Our results support the view that brain iron mobilization or homeostasis is impaired in RLS.
Study objectives Studies on brain iron content in restless legs syndrome (RLS) using magnetic resonance imaging (MRI) are heterogeneous. In this study, we sought to leverage the availability of a large dataset including a range of iron-sensitive MRI techniques to reassess the association between brain iron content and RLS with added statistical power and to compare these results to previous studies. Methods The relaxation rates R2, R2′, and R2* and quantitative susceptibility are MRI parameters strongly correlated to iron content. In general, these parameters are sensitive to magnetic field variations caused by iron particles. These parameters were quantified within iron-rich brain regions using a fully automatized approach in a cohort of 72 RLS patients and individually age and gender-matched healthy controls identified from an existing dataset acquired at the Sleep Laboratory of the Department of Neurology, Medical University of Innsbruck. 3 T-MRI measures were corrected for age and volume of the segmented brain nuclei and results were compared with previous findings in a meta-analysis. Results In our cohort, RLS patients had increased R2* signal in the caudate and increased quantitative susceptibility signal in the putamen and the red nucleus compared to controls, suggesting increased iron content in these areas. The meta-analysis revealed no significant pooled effect across all brain regions. Furthermore, potential publication bias was identified for the substantia nigra. Conclusions Normal and increased iron content of subcortical brain areas detected in this study is not in line with the hypothesis of reduced brain iron storage, but favors CSF investigations and post mortem studies indicating alteration of brain iron mobilization and homeostasis in RLS.
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Affiliation(s)
- Vincent Beliveau
- Medical University of Innsbruck, Department of Neurology, Innsbruck, Austria; Medical University of Innsbruck, Neuroimaging Research Core Facility, Innsbruck, Austria
| | - Ambra Stefani
- Medical University of Innsbruck, Department of Neurology, Innsbruck, Austria
| | - Christoph Birkl
- Medical University of Innsbruck, Department of Neuroradiology, Innsbruck, Austria
| | - Christian Kremser
- Medical University of Innsbruck, Department of Radiology, Innsbruck, Austria
| | - Elke R Gizewski
- Medical University of Innsbruck, Department of Neuroradiology, Innsbruck, Austria; Medical University of Innsbruck, Department of Radiology, Innsbruck, Austria
| | - Birgit Högl
- Medical University of Innsbruck, Department of Neurology, Innsbruck, Austria
| | - Christoph Scherfler
- Medical University of Innsbruck, Department of Neurology, Innsbruck, Austria; Medical University of Innsbruck, Neuroimaging Research Core Facility, Innsbruck, Austria.
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14
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Restless Legs Syndrome: Known Knowns and Known Unknowns. Brain Sci 2022; 12:brainsci12010118. [PMID: 35053861 PMCID: PMC8773543 DOI: 10.3390/brainsci12010118] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 01/09/2022] [Accepted: 01/12/2022] [Indexed: 02/06/2023] Open
Abstract
Although restless legs syndrome (RLS) is a common neurological disorder, it remains poorly understood from both clinical and pathophysiological perspectives. RLS is classified among sleep-related movement disorders, namely, conditions characterized by simple, often stereotyped movements occurring during sleep. However, several clinical, neurophysiological and neuroimaging observations question this view. The aim of the present review is to summarize and query some of the current concepts (known knowns) and to identify open questions (known unknowns) on RLS pathophysiology. Based on several lines of evidence, we propose that RLS should be viewed as a disorder of sensorimotor interaction with a typical circadian pattern of occurrence, possibly arising from neurochemical dysfunction and abnormal excitability in different brain structures.
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15
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Nardone R, Sebastianelli L, Versace V, Orioli A, Saltuari L, Trinka E, Höller Y. Involvement of central sensory pathways in subjects with restless legs syndrome: A neurophysiological study. Brain Res 2021; 1772:147673. [PMID: 34597651 DOI: 10.1016/j.brainres.2021.147673] [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: 08/03/2021] [Revised: 09/14/2021] [Accepted: 09/26/2021] [Indexed: 11/26/2022]
Abstract
In patients with restless legs syndrome (RLS) a motor cortical disinhibition has been reported in transcranial magnetic stimulation (TMS) studies, but the neuronal excitability in other cortical areas has been poorly explored. The aim of this study was the functional evaluation of thalamo-cortical circuits and inhibitory cortical responses in the sensory cortex in RLS. We assessed the high-frequency somatosensory evoked potentials (HF-SEP) in sixteen subjects suffering from RLS of different degrees of severity. In patients with severe or very severe RLS we found a significant desynchronization with amplitude reduction of both pre- and post-synaptic HF-SEP bursts, which suggest an impairment in the thalamo-cortical projections and in the cortical inhibitory interneurons activity, respectively. The assessment of the central sensory pathways by means of HF-SEP may shed light on the pathophysiological mechanisms of RLS.
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Affiliation(s)
- Raffaele Nardone
- Department of Neurology, Hospital of Merano (SABES-ASDAA), Merano-Meran, Italy; Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Spinal Cord Injury and Tissue Regeneration Center, Salzburg, Austria; Karl Landsteiner Institut für Neurorehabilitation und Raumfahrtneurologie, Salzburg, Austria.
| | - Luca Sebastianelli
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Vipiteno-Sterzing, Italy, and Research Department for Neurorehabilitation South Tyrol, Bolzano, Italy
| | - Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Vipiteno-Sterzing, Italy, and Research Department for Neurorehabilitation South Tyrol, Bolzano, Italy
| | - Andrea Orioli
- Department of Neurology, Hospital of Merano (SABES-ASDAA), Merano-Meran, Italy
| | - Leopold Saltuari
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Vipiteno-Sterzing, Italy, and Research Department for Neurorehabilitation South Tyrol, Bolzano, Italy; Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Eugen Trinka
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Centre for Cognitive Neuroscience, Salzburg, Austria; University for Medical Informatics and Health Technology, UMIT, Hall in Tirol, Austria
| | - Yvonne Höller
- Faculty of Psychology, University of Akureyri, Iceland
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16
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Sheng L, Zhao P, Ma H, Qi L, Yi Z, Shi Y, Zhong J, Shi H, Dai Z, Pan P. Grey matter alterations in restless legs syndrome: A coordinate-based meta-analysis. J Sleep Res 2021; 30:e13298. [PMID: 33554365 DOI: 10.1111/jsr.13298] [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: 11/27/2020] [Revised: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 01/18/2023]
Abstract
Brain structural abnormalities in idiopathic restless legs syndrome have long been debated. Voxel-based morphometry is an objective structural magnetic resonance imaging technique to investigate regional grey matter volume or density differences between groups. In the last decade, voxel-based morphometry studies have exhibited inconsistent and conflicting findings regarding the presence and localization of brain grey matter alterations in restless legs syndrome. We therefore conducted a coordinate-based meta-analysis to quantitatively examine whether there were consistent grey matter findings in restless legs syndrome using the latest algorithms, seed-based d mapping with permutation of subject images. We included 12 voxel-based morphometry studies (13 datasets, 375 patients and 385 healthy controls). Our coordinate-based meta-analysis did not identify evidence of consistent grey matter alterations in restless legs syndrome. Grey matter alterations via voxel-based morphometry analysis are not therefore recommended to be used as a reliable surrogate neuroimaging marker for restless legs syndrome. This lack of consistency may be attributed to differences in sample size, genetics, gender distribution and age at onset, clinical heterogeneity (clinical course, anatomical distribution of symptoms, disease severity, disease duration, abnormal sensory profiles and comorbidity), and variations in imaging acquisition, data processing and statistical strategies. Longitudinal studies with multimodal neuroimaging techniques are needed to determine whether structural changes are dynamic and secondary to functional abnormalities.
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Affiliation(s)
- LiQin Sheng
- Department of Neurology, Kunshan Hospital of Traditional Chinese Medicine, Kunshan, China
| | - PanWen Zhao
- Department of Central Laboratory, Affiliated Yancheng Hospital, School of Medicine, Southeast University, Yancheng, China
| | - HaiRong Ma
- Department of Neurology, Kunshan Hospital of Traditional Chinese Medicine, Kunshan, China
| | - Liang Qi
- Second People's Hospital of Huai'an City, The Affiliated Huai'an Hospital of Xuzhou Medical University, Huai'an, China
| | - ZhongQuan Yi
- Department of Central Laboratory, Affiliated Yancheng Hospital, School of Medicine, Southeast University, Yancheng, China
| | - YuanYuan Shi
- Department of Central Laboratory, Affiliated Yancheng Hospital, School of Medicine, Southeast University, Yancheng, China
| | - JianGuo Zhong
- Department of Neurology, Affiliated Yancheng Hospital, School of Medicine, Southeast University, Yancheng, China
| | - HaiCun Shi
- Department of Neurology, Affiliated Yancheng Hospital, School of Medicine, Southeast University, Yancheng, China
| | - ZhenYu Dai
- Department of Radiology, Affiliated Yancheng Hospital, School of Medicine, Southeast University, Yancheng, China
| | - PingLei Pan
- Department of Central Laboratory, Affiliated Yancheng Hospital, School of Medicine, Southeast University, Yancheng, China.,Department of Neurology, Affiliated Yancheng Hospital, School of Medicine, Southeast University, Yancheng, China
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17
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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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Badenoch J, Searle T, Watson I, Cavanna AE. Sensory symptoms in body-focused repetitive behaviors, restless legs syndrome, and Tourette syndrome: An overlap? Neurosci Biobehav Rev 2020; 119:320-332. [PMID: 33086129 DOI: 10.1016/j.neubiorev.2020.10.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/13/2020] [Accepted: 10/15/2020] [Indexed: 12/25/2022]
Abstract
Tourette syndrome (TS) is a neurodevelopmental condition characterized by multiple tics. Sensory symptoms play a key role in the clinical phenomenology and pathophysiology of TS, as most patients report premonitory urges driving tic expression. Interestingly, sensory symptoms have also been reported in other conditions characterized by repeated behaviors. This review explores the nature of sensory symptoms reported by patients with body focused repetitive behaviors (BFRBs, especially trichotillomania and skin picking disorder) and restless legs syndrome (RLS) in comparison to TS. A sense of mounting inner tension and reinforcement mechanisms driven by gratification and relief on expression of the tic or repetitive behavior appear to be implicated across all conditions. Subjective urges can be temporarily suppressed by patients with TS and selected BFRBs, whereas patients with RLS tend to report dysesthesia more frequently than a suppressible urge to move. The observed similarities in the phenomenology of sensory symptoms across these conditions raise the possibility of a comparable underlying pathophysiology. Preliminary findings suggest an overlap of neural pathways encompassing the insula, basal ganglia (putamen), and posterior cingulate cortex.
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Affiliation(s)
- James Badenoch
- Department of Neuropsychiatry, BSMHFT and University of Birmingham, Birmingham, United Kingdom
| | - Tamara Searle
- Department of Neuropsychiatry, BSMHFT and University of Birmingham, Birmingham, United Kingdom
| | - Iona Watson
- Department of Neuropsychiatry, BSMHFT and University of Birmingham, Birmingham, United Kingdom
| | - Andrea E Cavanna
- Department of Neuropsychiatry, BSMHFT and University of Birmingham, Birmingham, United Kingdom; School of Life and Health Sciences, Aston University, Birmingham, United Kingdom; University College London and Institute of Neurology, London, United Kingdom.
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19
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Altered cortical gray matter volume and functional connectivity after transcutaneous spinal cord direct current stimulation in idiopathic restless legs syndrome. Sleep Med 2020; 74:254-261. [DOI: 10.1016/j.sleep.2020.07.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/18/2020] [Accepted: 07/20/2020] [Indexed: 01/18/2023]
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20
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Which Factors in Spinocerebellar Ataxia Type 3 Patients Are Associated with Restless Legs Syndrome/Willis-Ekbom Disease? THE CEREBELLUM 2020; 20:21-30. [PMID: 32946033 DOI: 10.1007/s12311-020-01170-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
There is evidence of a higher prevalence of restless legs syndrome/Willis-Ekbom disease (RLS/WED) in individuals with spinocerebellar ataxia type 3 (SCA3), although the factors underlying this association remain unknown. The present study aimed to determine the prevalence of RLS/WED in SCA3 patients and to investigate which factors of SCA3 patients are associated with presence of RLS/WED. From February to August of 2006, we carried out clinical interviews in 40 controls and 40 SCA3 patients, diagnosed and followed up at Faculty of Medicine of Ribeirão Preto, University of São Paulo. Twenty-seven SCA3 patients were submitted to a detailed clinical protocol, electroneuromyography, blood work up, polysomnography (PSG), suggested immobilization test (SIT), and magnetic resonance image (MRI). RLS/WED was found in 27.5% of SCA3 patients and 2.5% of normal controls (p = 0.003). The factors related to RLS/WED in SCA3 patients were female gender, age at start of the symptoms of ataxia after 30 years, presence of peripheral neuropathy, and documented iron deficiency. Among SCA3 patients, those with RLS showed higher values of maximal discomfort level and discomfort level sum compared to non-RLS individuals on SIT. There is a relation between RLS/WED and SCA3, which seems to be resultant of different factors whose identification could improve the quality of assistance to those patients as well as to promote a better comprehension of the pathophysiology of both RLS/WED and SCA3.
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21
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Zeng M, Wang L, Cheng B, Qi G, He J, Xu Z, Han T, Liu C, Wang Y. Transcutaneous Spinal Cord Direct-Current Stimulation Modulates Functional Activity and Integration in Idiopathic Restless Legs Syndrome. Front Neurosci 2020; 14:873. [PMID: 32982669 PMCID: PMC7475652 DOI: 10.3389/fnins.2020.00873] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 07/27/2020] [Indexed: 11/13/2022] Open
Abstract
Idiopathic restless legs syndrome (RLS) is a sensorimotor disorder and is suggested to be caused by central nervous system abnormalities. Non-invasive transcutaneous spinal direct-current stimulation (tsDCS) was recently used for RLS therapy. However, the neurophysiological basis of tsDCS treatment is still unknown. In this study, we explored the neural basis of tsDCS in 15 RLS patients and 20 gender- and age-matched healthy controls using resting-state functional magnetic resonance imaging. We calculated the whole-brain voxel-wise fractional amplitude of low-frequency fluctuations (fALFF), regional homogeneity (ReHo), and weighted degree centrality (DC) to characterize the intrinsic functional activities and the local and global functional integration. We found that tsDCS can effectively improve the sleep and RLS symptoms in RLS patients. Moreover, after tsDCS therapy, the RLS patients showed decreased fALFF in the right anterior insula/temporal pole, decreased ReHo in the supplementary motor area, increased weighted DC in the left primary visual cortex, and decreased weighted DC in the right posterior cerebellum. The changed patterns were consistent with that found between RLS patients and healthy controls. The weighted DC in the left primary visual cortex after treatment and the fALFF in the right anterior insula/temporal pole before treatment were significantly and marginally correlated with sleep and RLS symptom scores, respectively. These results revealed that tsDCS can normalize the functional patterns of RLS patients and is an effective way for RLS therapy. Our findings provide the neurophysiological basis for tsDCS treatment and may facilitate understanding the neuropathology of RLS and directing other neuromodulation treatments.
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Affiliation(s)
- Min Zeng
- Department of Radiology, Pidu District People's Hospital, Chengdu, China
| | - Li Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China
| | - Bochao Cheng
- Department of Radiology, West China Second University Hospital of Sichuan University, Chengdu, China
| | - Guiqiang Qi
- Department of Radiology, Pidu District People's Hospital, Chengdu, China
| | - Junwei He
- Department of Radiology, Pidu District People's Hospital, Chengdu, China
| | - Zhexue Xu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China
| | - Tao Han
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China
| | - Chunyan Liu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China
| | - Yuping Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China
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22
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Kocar TD, Müller HP, Kassubek J. Differential functional connectivity in thalamic and dopaminergic pathways in restless legs syndrome: a meta-analysis. Ther Adv Neurol Disord 2020; 13:1756286420941670. [PMID: 32821291 PMCID: PMC7412904 DOI: 10.1177/1756286420941670] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/22/2020] [Indexed: 12/13/2022] Open
Abstract
Objective: Restless legs syndrome (RLS) is a sensorimotor disorder with alterations in somatosensory processing in association with a dysfunctional cerebral network, involving the basal ganglia, limbic network, and sensorimotor pathways. Resting state functional magnetic resonance imaging (MRI) is a powerful tool to provide in vivo insight into functional processing and as such is of special interest in RLS considering the widespread pattern of networks involved in this disorder. In this meta-analysis of resting state functional MRI studies, we analyzed the preponderance of functional connectivity changes associated with RLS and discussed possible links to sensorimotor dysfunction and somatosensory processing. Methods: A systematic research using the online library PubMed was conducted and a total of seven studies passed the inclusion criteria of the meta-analysis. The results of these studies were merged and a statistical probability map was generated that indicated the likelihood of functional connectivity changes within the combined cohort, both for increased and decreased connectivity. Results: The meta-analysis demonstrated decreased functional connectivity within the dopaminergic network in participants with RLS compared with healthy controls, including the nigrostriatal, mesolimbic, and mesocortical pathways. Increased functional connectivity was observed bilaterally in the thalamus, including its ventral lateral, ventral anterior, and ventral posterior lateral nuclei, and the pulvinar. Discussion: Sensorimotor dysfunction in RLS seems to be reflected by decreased functional connectivity within the dopaminergic pathways. Network extension in the thalamus can be regarded as an adaptation to somatosensory dysfunction in RLS. This differential functional connectivity pattern extends prior findings on cerebral somatosensory processing in RLS and offers an explanation for the efficacy of dopaminergic treatment.
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Affiliation(s)
| | | | - Jan Kassubek
- Department of Neurology, University of Ulm, Oberer Eselsberg 45, Ulm, 89081, Germany
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23
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Patterns of Gray Matter Volume Alterations in Hemodialysis Patients With and Without Restless Legs Syndrome: Evidence From a Voxel-Based Morphometry Study. J Comput Assist Tomogr 2020; 44:533-539. [PMID: 32697523 DOI: 10.1097/rct.0000000000001034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
PURPOSE The purpose of this study was to investigate the differences of gray matter volume (GMV) alteration patterns between hemodialysis with restless legs syndrome (HD-RLS) and hemodialysis without restless legs syndrome (HD-nRLS) patients using voxel-based morphometry. METHODS Twenty-three HD-RLS patients, 27 HD-nRLS patients, and 27 age-, sex-, and education-matched healthy controls were included in this study. One-way analysis of covariance and post hoc analyses were used to assess differences in GMV, demographics, and clinical data among the 3 groups. Pearson correlation analysis was conducted between altered GMV in the HD-RLS group and clinical data. RESULTS Compared with HD-nRLS patients, HD-RLS patients showed decreased GMV in the left primary motor cortex (false discovery rate corrected, P < 0.05). Compared with the healthy controls, both HD subgroups (ie, those with and without RLS) exhibited consistent GMV changes, including decreased GMV in the bilateral anterior cingulate and paracingulate gyrus and left middle temporal gyrus (false discovery rate corrected, P < 0.05). The GMV values in the left precentral gyrus were negatively correlated with the RLS rating scores (r = 0.2138, P = 0.0263). CONCLUSIONS This abnormal decreased GMV in the sensorimotor cortex provides evidence for a sensory processing disorder in RLS that may be involved in the pathogenesis of RLS in HD patients.
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24
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Allen RP, Earley CJ, Jones BC, Unger EL. Iron-deficiency and dopaminergic treatment effects on RLS-Like behaviors of an animal model with the brain iron deficiency pattern of the restless legs syndrome. Sleep Med 2020; 71:141-148. [PMID: 32094092 PMCID: PMC7302997 DOI: 10.1016/j.sleep.2020.01.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/16/2020] [Accepted: 01/20/2020] [Indexed: 11/16/2022]
Abstract
BACKGROUND Brain iron deficiency (BID), especially for the substantia nigra (SN), without peripheral iron deficiency (ID) has been well documented as a ubiquitous finding for restless legs syndrome (RLS) patients. This close association suggests the biology of RLS BID can produce RLS symptoms. Association, however, cannot establish such a direct relationship. Instead, the BID of RLS could be experimentally produced to determine if it then produces significant RLS-like biological or behavioral features. Forward genetics approach led to identification from the BXD strains the BXD40 females (BXD40f) as a putative animal model for the RLS BID. The BXD40f on an iron-sufficient diet have a lower iron in the VMB (containing the SN) during the active but not inactive period. This was not found for the other BXD strains evaluated. The BXD40f on an ID diet uniquely have even greater reduced VMB but not peripheral iron, matching the RLS BID pathophysiology. A prior report found that the BXD40f on an iron-sufficient diet had an RLS-like behavior of increased activity occurring only in the last part of the active period that was not present in the other strains without the low VMB iron. This increased activity matches the circadian pattern of symptoms in RLS patients with increased urge or drive to move in the last part of the day. This study asks first: if you decrease the VMB iron by an iron deficient diet do the RLS-like behaviors worsen; and second will the dopaminergic treatments effective for RLS also reduce the worsened RLSlike behaviors. METHODS In sum, 13 BXD40f mice post weaning were randomly assigned for 100 days to either a iron-sufficient diet (n = 6) or an ID diet (N = 7). They were then evaluated for 24-h activity in their home cage using implanted G2 EMitter telemetry device. At 3 h before the end of the active period IP doses were given every other day of either: saline (vehicle only), 12.5 mg levodopa, 25 mg levodopa, 0.5 mg quinpirole, or 1 0.0 mg quinpirole. RESULTS The ID compared to irons-sufficient diet produced earlier onset of the RLS-like behavior matching the earlier onset of symptoms with increasing severity of RLS. The dopaminergic treatments significantly reduced the RLS-like behavior. Added analyses of the RLS-like behaviors as decreased resting times showed similar results to activity increases. CONCLUSIONS These data demonstrate both that The BXD40f provide a useful animal model of RLS and also strongly support the hypothesis that the biology of RLS BID can produce RLS symptoms.
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Affiliation(s)
- Richard P Allen
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
| | - Christopher J Earley
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Byron C Jones
- Department of Genetics, Genomics and Informatics, University of Tennessee, Memphis, TN, USA
| | - Erica L Unger
- Department of Biology, Lebanon Valley College, Annville, PA, USA
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25
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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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26
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Aldemir A, Yucel K, Güven H, Kamaşak B, Dilli A, Acer N, Çomoğlu S. Structural neuroimaging findings in migraine patients with restless legs syndrome. Neuroradiology 2020; 62:1301-1313. [PMID: 32488307 DOI: 10.1007/s00234-020-02451-7] [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: 01/31/2020] [Accepted: 04/28/2020] [Indexed: 12/27/2022]
Abstract
PURPOSE One out of three migraine patients might have accompanying restless legs syndrome (RLS). In our study, we aimed to compare the volumes of the brain structures of migraineurs with and without RLS. METHODS We had 37 female patients with migraine and 17 females as the control group. Nineteen migraineurs had no RLS (RLS0) and 18 migraineurs had comorbidity of RLS (RLS1). The volumes of the brain structures were obtained by manual measurements, volBrain, and voxel-based morphometry (VBM). Manually, we measured caudate and putamen volumes. We used age, years of education, depression, anxiety scores, and total intracranial volume as covariates. RESULTS According to VBM analyses, the volumes of the left superior occipital gyrus and precuneus were increased, and the substantia nigra and cuneus were decreased in the RLS1 group compared with the RLS0 group. RLS1 patients had larger superior temporal gyrus, Brodmann area 38, and left insula, and RLS0 patients had larger Brodmann area 22, right superior temporal gyrus, and Heschl gyrus compared with controls. Migraine and RLS0 patients had a smaller corpus callosum anteriorly, whereas RLS1 patients had a smaller splenium. Caudate volumes were larger in migraine patients via the three techniques. There was a positive relation between the caudate and putamen volumes and attack frequency. CONCLUSIONS Comorbidity of RLS might be a confounding factor in structural neuroimaging studies in migraine. Deficits in the visual network seem to be related to accompanying RLS; deficits in the auditory network are particularly related to migraine.
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Affiliation(s)
- Arzu Aldemir
- Department of Neurology, Acıbadem Hospital, Eskişehir, Turkey
| | - Kaan Yucel
- Department of Anatomy, Aksaray University Medical School, Aksaray, Turkey.
| | - Hayat Güven
- Department of Neurology, Dışkapı Yıldırım Beyazıt Training and Research Hospital, University of Health Sciences, Ankara, Turkey
| | - Burcu Kamaşak
- Department of Anatomy, Ahi Evran University Medical School, Kırşehir, Turkey
| | - Alper Dilli
- Department of Radiology, Dışkapı Yıldırım Beyazıt Training and Research Hospital, University of Health Sciences, Ankara, Turkey
| | - Niyazi Acer
- Department of Anatomy, Erciyes University Medical School, Kayseri, Turkey
| | - Selçuk Çomoğlu
- Department of Neurology, Dışkapı Yıldırım Beyazıt Training and Research Hospital, University of Health Sciences, Ankara, Turkey
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27
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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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28
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Brain regions associated with periodic leg movements during sleep in restless legs syndrome. Sci Rep 2020; 10:1615. [PMID: 32005856 PMCID: PMC6994717 DOI: 10.1038/s41598-020-58365-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 01/07/2020] [Indexed: 11/24/2022] Open
Abstract
The neural substrates related to periodic leg movements during sleep (PLMS) remain uncertain, and the specific brain regions involved in PLMS have not been evaluated. We investigated the brain regions associated with PLMS and their severity using the electroencephalographic (EEG) source localization method. Polysomnographic data, including electromyographic, electrocardiographic, and 19-channel EEG signals, of 15 patients with restless legs syndrome were analyzed. We first identified the source locations of delta-band (2–4 Hz) spectral power prior to the onset of PLMS using a standardized low-resolution brain electromagnetic tomography method. Next, correlation analysis was conducted between current densities and PLMS index. Delta power initially and most prominently increased before leg movement (LM) onset in the PLMS series. Sources of delta power at −4~−3 seconds were located in the right pericentral, bilateral dorsolateral prefrontal, and cingulate regions. PLMS index was correlated with current densities at the right inferior parietal, temporoparietal junction, and middle frontal regions. In conclusion, our results suggest that the brain regions activated before periodic LM onset or associated with their severity are the large-scale motor network and provide insight into the cortical contribution of PLMS pathomechanism.
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29
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Wang H, Han X, Jin M, Wang LY, Diao ZL, Guo W, Zhang P, Wang Z, Ding HY, Lv H, Zhang ZY, Zhao PF, Li J, Yang ZH, Liu WH, Wang ZC. Different iron deposition patterns in hemodialysis patients with and without restless legs syndrome: a quantitative susceptibility mapping study. Sleep Med 2020; 69:34-40. [PMID: 32045852 DOI: 10.1016/j.sleep.2019.12.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 12/13/2019] [Accepted: 12/29/2019] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Brain iron deposition in hemodialysis (HD) patients increases over time. Iron deficiency in gray matter nuclei has been reported to lead to idiopathic restless legs syndrome (RLS) symptoms. Regardless of unpleasant RLS sensations, the patterns of iron deposition between hemodialysis patients with RLS (HD-RLS) and hemodialysis patients without RLS (HD-nRLS) are still unclear. To evaluate the differences in iron deposition patterns between HD-RLS and HD-nRLS patients, we utilized quantitative susceptibility mapping (QSM). METHODS In sum, 24 HD-RLS patients, 25 HD-nRLS patients and 30 age- and sex-matched healthy controls (HCs) were enrolled. The QSM was used to assess susceptibility values of the regions of interest (ROIs), including the caudate nucleus (CN), putamen (PUT), globus pallidus (GP), thalamus (THA), substantia nigra (SN), red nucleus (RN) and dentate nucleus (DN). RESULTS HD duration was significantly longer in HD-RLS patients than in HD-nRLS patients (P < 0.05). The susceptibility of HD-RLS and HD-nRLS patients in PUT was higher than that in HCs (P < 0.05), illustrating elevated iron content in the nucleus. Compared with HD-nRLS patients, HD-RLS patients demonstrated reduced susceptibility in CN and PUT (both P < 0.05). Compared with HCs, HD-RLS patients displayed decreased susceptibility in DN (P < 0.05). CONCLUSIONS Different iron deposition patterns between HD-RLS and HD-nRLS patients in PUT and DN, which further support disturbed sensory processing in RLS, may be involved in RLS pathogenesis in HD patients.
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Affiliation(s)
- Hao Wang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Xue Han
- Department of Nephrology, Faculty of Kidney Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Mei Jin
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Li-Yan Wang
- Department of Nephrology, Faculty of Kidney Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Zong-Li Diao
- Department of Nephrology, Faculty of Kidney Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Wang Guo
- Department of Nephrology, Faculty of Kidney Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Peng Zhang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Zheng Wang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - He-Yu Ding
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Han Lv
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Zheng-Yu Zhang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Peng-Fei Zhao
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Jing Li
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Zheng-Han Yang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Wen-Hu Liu
- Department of Nephrology, Faculty of Kidney Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
| | - Zhen-Chang Wang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
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30
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Munhoz RP, Constantino MCL, Silveira-Moriyama L. The Parkinson's disease and restless legs syndrome/Willis-Ekbom disorder link: evidences, biases and clinical relevance. ARQUIVOS DE NEURO-PSIQUIATRIA 2019; 77:47-54. [PMID: 30758442 DOI: 10.1590/0004-282x20180125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 09/05/2018] [Indexed: 11/21/2022]
Abstract
Parkinson's disease (PD) and restless legs syndrome/Willis-Ekbom disorder (RLS/WED) are relatively common diseases in the realm of movement disorders. The fact that both may, as expected, co-occur and typically share a similar remarkable response to dopaminergic treatment raised the interest in exploration of additional shared features that throughout the years cruised fields as diverse as phenomenology, epidemiology, genetics, pathology, and clinical studies. In this review, we describe and critically examine the evidence and biases of a conceivable overlap of these two disorders, trying to shed light onto two main sources of confusion: (1) are PD and RLS/WED reciprocal risk factors? and (2) what are the main mimics of RLS/WED in PD?
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Affiliation(s)
- Renato Puppi Munhoz
- University of Toronto, Toronto Western Hospital, Movement Disorders Centre, Toronto ON, Canada.,Krembil Research Institute, Toronto, Ontario, Canada
| | | | - Laura Silveira-Moriyama
- Universidade Nove de Julho, São Paulo SP, Brasil.,Universidade Estadual de Campinas, Departamento de Neurologia, Campinas SP, Brasil
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31
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Lyu S, Xing H, DeAndrade MP, Perez PD, Zhang K, Liu Y, Yokoi F, Febo M, Li Y. The role of BTBD9 in the cerebral cortex and the pathogenesis of restless legs syndrome. Exp Neurol 2019; 323:113111. [PMID: 31715135 DOI: 10.1016/j.expneurol.2019.113111] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 10/09/2019] [Accepted: 11/07/2019] [Indexed: 01/18/2023]
Abstract
Restless legs syndrome (RLS) is a nocturnal neurological disorder affecting up to 10% of the population. It is characterized by an urge to move and uncomfortable sensations in the legs which can be relieved by movements. Mutations in BTBD9 may confer a higher risk of RLS. We developed Btbd9 knockout mice as an animal model. Functional alterations in the cerebral cortex, especially the sensorimotor cortex, have been found in RLS patients in several imaging studies. However, the role of cerebral cortex in the pathogenesis of RLS remains unclear. To explore this, we used in vivo manganese-enhanced MRI and found that the Btbd9 knockout mice had significantly increased neural activities in the primary somatosensory cortex (S1) and the rostral piriform cortex. Morphometry study revealed a decreased thickness in a part of S1 representing the hindlimb (S1HL) and M1. The electrophysiological recording showed Btbd9 knockout mice had enhanced short-term plasticity at the corticostriatal terminals to D1 medium spiny neurons (MSNs). Furthermore, we specifically knocked out Btbd9 in the cerebral cortex of mice (Btbd9 cKO). The Btbd9 cKO mice showed a rest-phase specific motor restlessness, decreased thermal sensation, and a thinner S1HL and M1. Both Btbd9 knockout and Btbd9 cKO exhibited motor deficits. Our results indicate that systematic BTBD9 deficiency leads to both functional and morphometrical changes of the cerebral cortex, and an alteration in the corticostriatal pathway to D1 MSNs. Loss of BTBD9 only in the cerebral cortex is sufficient to cause similar phenotypes as observed in the Btbd9 complete 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, Florida, USA
| | - Hong Xing
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Mark P DeAndrade
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Pablo D Perez
- Department of Psychiatry, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Keer Zhang
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Yuning Liu
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Fumiaki Yokoi
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Marcelo Febo
- Department of Psychiatry, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Yuqing Li
- Norman Fixel Institute for Neurological Diseases, Department of Neurology, College of Medicine, University of Florida, Gainesville, Florida, USA.
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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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Li Z, Chen J, Lin Y, Zhou M, Cai Q, Li X, Wu Z, Chen X, Yang X, Zhu X, Lu J, Zhang L, Liu B, Luo X, Xu P. Reduced regional activity and functional connectivity within sensorimotor network in Parkinson's patients with restless legs syndrome. Mol Pain 2019; 15:1744806919882272. [PMID: 31554460 DOI: 10.1177/1744806919882272] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Affiliation(s)
- Zhe Li
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jun Chen
- Department of Radiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yuwan Lin
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Miaomiao Zhou
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Qiaodi Cai
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xinchun Li
- Department of Radiology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Zhuohua Wu
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xinjie Chen
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xinling Yang
- Department of Neurology, The Second Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Xiaoqin Zhu
- Department of Physiology, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Jianjun Lu
- Department of Neurosurgery, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Li Zhang
- Department of Geriatrics, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Bo Liu
- Department of Radiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xiaodong Luo
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Pingyi Xu
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Department of Physiology, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
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Magalhães SC, Queiroz de Paiva JP, Kaelin-Lang A, Sterr A, Eckeli AL, Winkler AM, Fernandes do Prado G, Amaro E, Conforto AB. Short-interval intracortical inhibition is decreased in restless legs syndrome across a range of severity. Sleep Med 2019; 62:34-42. [PMID: 31539846 DOI: 10.1016/j.sleep.2019.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 03/10/2019] [Accepted: 03/12/2019] [Indexed: 01/18/2023]
Abstract
BACKGROUND Decreased short-interval intracortical inhibition (SICI) to transcranial magnetic stimulation (TMS) of the primary motor cortex was described in subjects with restless legs syndrome/Willis-Ekbom disease (RLS/WED). It remained to be determined whether the magnitude of SICI decrease would be similar across levels of RLS/WED severity. Moreover, it was unknown whether, in addition to decreases in SICI, changes in cortical thickness or area could be detected in subjects with RLS/WED compared to controls. The objective of this study was to compare SICI, cortical thickness, and cortical area in subjects with idiopathic mild to moderate RLS/WED, severe to very severe RLS/WED, and controls. METHODS The severity of RLS/WED was assessed by the International Restless Legs Syndrome Severity Scale (IRLSS). SICI and 3T magnetic resonance imaging (MRI) data of subjects with RLS/WED and controls were compared. A receiver operating characteristic curve for SICI was designed for discrimination of participants with RLS/WED from controls. Cortical thickness and area were assessed by automated surface-based analysis. RESULTS SICI was significantly reduced in patients with mild to moderate and severe to very severe RLS/WED, compared to controls (one-way analysis of variance: F = 9.62, p < 0.001). Receiver operating characteristic curve analysis predicted RLS/WED when SICI was above 35% (area under the curve = 0.79, 95% CI 0.67-0.91, p < 0.001). Analyses of the whole brain and of regions of interest did not reveal differences in gray matter thickness or area between controls and subjects with RLS/WED. CONCLUSION SICI is an accurate cortical biomarker that can support the diagnosis of RLS/WED even in subjects with mild symptoms, but cortical thickness and area were not useful for discriminating subjects with this condition from controls.
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Affiliation(s)
- Samir Câmara Magalhães
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil; Universidade de Fortaleza, Unifor, Fortaleza, CE, Brazil.
| | | | | | - Annette Sterr
- Department of Psychology, University of Surrey, Guildford, Surrey, UK
| | - Alan Luiz Eckeli
- Departamento de Neurociências e Ciências do Comportamento, Divisão de Neurologia, Hospital das Clínicas da Faculdade de Medicina da USP-Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | | | | | - Edson Amaro
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil; Departamento de Radiologia, Hospital das Clínicas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Adriana Bastos Conforto
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil; Departamento de Neurologia, Hospital das Clínicas, Universidade de São Paulo, São Paulo, SP, Brazil
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Stefani A, Mitterling T, Heidbreder A, Steiger R, Kremser C, Frauscher B, Gizewski ER, Poewe W, Högl B, Scherfler C. Multimodal Magnetic Resonance Imaging reveals alterations of sensorimotor circuits in restless legs syndrome. Sleep 2019; 42:5539066. [DOI: 10.1093/sleep/zsz171] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/22/2019] [Indexed: 01/18/2023] Open
Abstract
AbstractStudy ObjectivesIntegrated information on brain microstructural integrity and iron storage and its impact on the morphometric profile is not available in restless legs syndrome (RLS). We applied multimodal magnetic resonance imaging (MRI) including diffusion tensor imaging, the transverse relaxation rate (R2*), a marker for iron storage, as well as gray and white matter volume measures to characterize RLS-related MRI signal distribution patterns and to analyze their associations with clinical parameters.MethodsEighty-seven patients with RLS (mean age 51, range 20–72 years; disease duration, mean 13 years, range 1–46 years, of those untreated n = 30) and 87 healthy control subjects, individually matched for age and gender, were investigated with multimodal 3T MRI.ResultsVolume of the white matter compartment adjacent to the post- and precentral cortex and fractional anisotropy (FA) of the frontopontine tract were both significantly reduced in RLS compared to healthy controls, and these alterations were associated with disease duration (r = 0.25, p = 0.025 and r = 0.23, p = 0.037, respectively). Corresponding gray matter volume increases of the right primary motor cortex in RLS (p < 0.001) were negatively correlated with the right FA signal of the frontopontine tract (r = −0.22; p < 0.05). Iron content evaluated with R2* was reduced in the putamen as well as in temporal and occipital compartments of the RLS cohort compared to the control group (p < 0.01).ConclusionsMultimodal MRI identified progressing white matter decline of key somatosensory circuits that may underlie the perception of sensory leg discomfort. Increases of gray matter volume of the premotor cortex are likely to be a consequence of functional neuronal reorganization.
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Affiliation(s)
- Ambra Stefani
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Thomas Mitterling
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Anna Heidbreder
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Ruth Steiger
- Neuroimaging Research Core Facility, Medical University of Innsbruck, Innsbruck, Austria
- Department of Neuroradiology, Medical University Innsbruck, Innsbruck, Austria
| | - Christian Kremser
- Department of Radiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Birgit Frauscher
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Elke R Gizewski
- Neuroimaging Research Core Facility, Medical University of Innsbruck, Innsbruck, Austria
- Department of Neuroradiology, Medical University Innsbruck, Innsbruck, Austria
| | - Werner Poewe
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Birgit Högl
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Christoph Scherfler
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
- Neuroimaging Research Core Facility, Medical University of Innsbruck, Innsbruck, Austria
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Zhu XY, Wu TT, Wang HM, Ni LY, Li X, Liu Y, Zhang XJ, Chen YJ, Cui XX, Ondo WG, Wu YC. Clinical features and subtypes of restless legs syndrome in Chinese population: a study of 359 patients. Sleep Med 2019; 59:15-23. [DOI: 10.1016/j.sleep.2019.01.053] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/14/2019] [Accepted: 01/31/2019] [Indexed: 10/27/2022]
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Ghorayeb I. Idiopathic restless legs syndrome treatment: Progress and pitfalls? PHARMACOLOGY OF RESTLESS LEGS SYNDROME (RLS) 2019; 84:207-235. [DOI: 10.1016/bs.apha.2019.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Lanza G, Ferri R. The neurophysiology of hyperarousal in restless legs syndrome: Hints for a role of glutamate/GABA. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2019; 84:101-119. [PMID: 31229167 DOI: 10.1016/bs.apha.2018.12.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Restless legs syndrome (RLS) is a common sensory-motor circadian disorder, whose basic components include urge to move the legs, unpleasant sensory experience, and periodic leg movements during sleep, all associated with an enhancement of the individual's arousal state. Brain iron deficiency (BID) is considered to be a key initial pathobiological factor, based on alterations of iron acquisition by the brain, also moderated by genetic factors. In addition to the well-known dopaminergic involvement in RLS, previous studies pointed out that BID brings also a hyperglutamatergic state that influences a dysfunctional cortico-striatal-thalamic-cortical circuit in genetically vulnerable individuals. However, the enhancement of arousal mechanisms in RLS may also be explained by functional changes of the ascending arousal systems and by deficitary GABA-mediated inhibitory control. Very recently, it was also suggested that BID induces a hypoadenosinergic state in RLS, thus possibly providing a link for a putative unified pathophysiological mechanism accounting for both hyperarousal and sensory-motor signs. Consequently, RLS might be viewed as a multitransmitter neurochemical disorder, globally resulting in enhanced excitability and decreased inhibition. In this framework, understanding the complex interaction of different neuronal circuits in generating the symptoms of RLS is mandatory both for a better diagnostic refinement and for an innovative therapeutic support. Notably, multiple neurotransmission dysfunction, either primary or triggered by BID, may also bridge the gap between RLS and other chronic pain disorders. This chapter summarizes the current experimental and clinical findings into a heuristic model of the electrophysiology and neurochemistry underlying RLS.
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Li T, Liu C, Lyu H, Xu Z, Hu Q, Xu B, Wang Y, Xu J. Alterations of Sub-cortical Gray Matter Volume and Their Associations With Disease Duration in Patients With Restless Legs Syndrome. Front Neurol 2018; 9:1098. [PMID: 30619055 PMCID: PMC6304426 DOI: 10.3389/fneur.2018.01098] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 12/03/2018] [Indexed: 01/18/2023] Open
Abstract
Object: The purpose of this study was to uncover the pathology of restless legs syndrome (RLS) by exploring brain structural alterations and their corresponding functional abnormality. Method: Surface-based morphometry (SBM) and voxel-based morphometry (VBM) were performed to explore the alterations in cortical and sub-cortical gray matter volume (GMV) in a cohort of 20 RLS and 18 normal controls (NC). Furthermore, resting-state functional connectivity (RSFC) was also performed to identify the functional alterations in patients with RLS. Results: We found significant alterations of sub-cortical GMV, especially the bilateral putamen (PUT), rather than alterations of cortical GMV in patients with RLS compared to NC using both SBM and VBM. Further sub-regional analysis revealed that GMV alterations of PUT was mostly located in the left dorsal caudal PUT in patients with RLS. In addition, altered RSFC patterns of PUT were identified in patients with RLS compared to NC. Moreover, correlation analyses showed that the GMV of the left caudate and the left ventral rostral PUT were positively correlated with disease duration in patients with RLS. Conclusions: The alterations of subcortical GMV might imply that the primarily affected areas are located in sub-cortical areas especially in the sub-region of PUT by the pathologic process of RLS, which might be used as potential biomarkers for the early diagnosis of RLS.
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Affiliation(s)
- Tian Li
- Department of Psychology, Faculty of Education, Hubei University, Wuhan, China.,Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Chunyan Liu
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China
| | - Hanqing Lyu
- Radiology Department, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - Zhexue Xu
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China
| | - Qingmao Hu
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Bibo Xu
- Department of Psychology, Faculty of Education, Hubei University, Wuhan, China
| | - Yuping Wang
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China
| | - Jinping Xu
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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Yang FC, Chou KH, Lee PL, Yin JH, Chen SY, Kao HW, Sung YF, Chou CH, Tsai CK, Tsai CL, Lin CP, Lee JT. Patterns of gray matter alterations in migraine and restless legs syndrome. Ann Clin Transl Neurol 2018; 6:57-67. [PMID: 30656184 PMCID: PMC6331309 DOI: 10.1002/acn3.680] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 09/29/2018] [Accepted: 10/01/2018] [Indexed: 01/18/2023] Open
Abstract
Objectives Migraine and restless legs syndrome (RLS) are often comorbid and share elements of pathology; however, their neuroanatomical underpinnings are poorly understood. This study aimed to identify patterns of gray matter volume (GMV) alteration specific to and common among patients with RLS, migraine, and comorbid migraine and RLS. Methods High‐resolution T1‐weighted images were acquired from 116 subjects: 27 RLS patients, 22 migraine patients, 22 patients with comorbid migraine and RLS, and 45 healthy controls. Direct group comparisons and conjunction analysis were first used to localize the distinct and shared neural signatures of migraine and RLS. We also investigated whether the shared neural signature could be replicated in an additional comorbid migraine/RLS group. Results Compared with healthy controls, migraine patients showed GMV changes in the lateral occipital cortex, cerebellum, frontal pole, and middle frontal gyrus (MFG), and RLS patients showed GMV changes in the thalamus, middle temporal gyrus, anterior cingulate cortex, insular cortex, and MFG. In migraine, compared with RLS, GMV differences were found in the precuneus, lateral occipital and occipital fusiform cortex, superior frontal and precentral gyri, and cerebellum. Conjunction analyses for these disorders showed altered GMV in the MFG, also found in patients with comorbid migraine and RLS. The GMV of the MFG also correlated with sleep quality in patients with comorbid migraine and RLS. Interpretation Migraine and RLS are characterized by shared and distinctive neuroanatomical characteristics, with a specific role of the MFG. These findings may be related to shared pathophysiology of these two distinct disorders.
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Affiliation(s)
- Fu-Chi Yang
- Department of Neurology Tri-Service General Hospital National Defense Medical Center Taipei Taiwan
| | - Kun-Hsien Chou
- Brain Research Center National Yang-Ming University Taipei Taiwan.,Institute of Neuroscience National Yang-Ming University Taipei Taiwan
| | - Pei-Lin Lee
- Department of Biomedical Imaging and Radiological Sciences National Yang-Ming University Taipei Taiwan
| | - Jiu-Haw Yin
- Department of Neurology Tri-Service General Hospital National Defense Medical Center Taipei Taiwan.,Division of Neurology Department of Medicine Cheng Hsin General Hospital Taipei Taiwan
| | - Shao-Yuan Chen
- Department of Neurology Cardinal Tien Hospital New Taipei City Taiwan.,Department of Hyperbaric Medicine Cardinal Tien Hospital New Taipei City Taiwan.,School of Medicine Fu-Jen Catholic University New Taipei City Taiwan
| | - Hung-Wen Kao
- Department of Radiology Tri-Service General Hospital National Defense Medical Center Taipei Taiwan
| | - Yueh-Feng Sung
- Department of Neurology Tri-Service General Hospital National Defense Medical Center Taipei Taiwan
| | - Chung-Hsing Chou
- Department of Neurology Tri-Service General Hospital National Defense Medical Center Taipei Taiwan.,Graduate Institute of Medical Sciences National Defense Medical Center Taipei Taiwan
| | - Chia-Kuang Tsai
- Department of Neurology Tri-Service General Hospital National Defense Medical Center Taipei Taiwan
| | - Chia-Lin Tsai
- Department of Neurology Tri-Service General Hospital National Defense Medical Center Taipei Taiwan
| | - Ching-Po Lin
- Brain Research Center National Yang-Ming University Taipei Taiwan.,Institute of Neuroscience National Yang-Ming University Taipei Taiwan.,Department of Biomedical Imaging and Radiological Sciences National Yang-Ming University Taipei Taiwan.,Institute of Brain Science National Yang-Ming University Taipei Taiwan
| | - Jiunn-Tay Lee
- Department of Neurology Tri-Service General Hospital National Defense Medical Center Taipei Taiwan.,Graduate Institute of Medical Sciences National Defense Medical Center Taipei Taiwan
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Comorbidities, treatment, and pathophysiology in restless legs syndrome. Lancet Neurol 2018; 17:994-1005. [PMID: 30244828 DOI: 10.1016/s1474-4422(18)30311-9] [Citation(s) in RCA: 142] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 07/05/2018] [Accepted: 08/08/2018] [Indexed: 12/11/2022]
Abstract
Restless legs syndrome, also known as Willis-Ekbom disease, is a common neurological condition whose manifestation is affected by complex environmental and genetic interactions. Restless legs syndrome can occur on its own, mostly at a young age, or with comorbidities such as cardiovascular disease, diabetes, and arterial hypertension, making it a difficult condition to properly diagnose. However, the concept of restless legs syndrome as being two entities, primary or secondary to another condition, has been challenged with genetic data providing further insight into the pathophysiology of the condition. Although dopaminergic treatment was formerly the first-line therapy, prolonged use can result in a serious worsening of symptoms known as augmentation. Clinical studies on pregabalin, gabapentin enacarbil, oxycodone-naloxone, and iron preparations have provided new treatment options, but most patients still report inadequate long-term management of symptoms. Studies of the hypoxic pathway activation and iron deficiency have provided valuable information about the pathophysiology of restless legs syndrome that should now be translated into new, more effective treatments for restless legs syndrome.
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Ferini-Strambi L, Carli G, Casoni F, Galbiati A. Restless Legs Syndrome and Parkinson Disease: A Causal Relationship Between the Two Disorders? Front Neurol 2018; 9:551. [PMID: 30087647 PMCID: PMC6066514 DOI: 10.3389/fneur.2018.00551] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 06/19/2018] [Indexed: 11/13/2022] Open
Abstract
Restless Legs Syndrome/Willis-Ekbom Disease (RLS/WED) is a common sleep related movement disorder that can be idiopathic or occurs in comorbidity with other medical conditions such as polyneuropathy, iron deficiency anemia, multiple sclerosis, hypertension and cardiovascular diseases. In recent years, a growing body of literature investigated the association between RLS/WED and Parkinson's Disease (PD). Several questions regarding the comorbidity between these two disorders are still unanswered. If the insurgence of RLS/WED may precede the onset of PD, or if RLS/WED could represent a secondary condition of PD and if impaired dopaminergic pathway may represent a bridge between these two conditions are still debatable issues. In this review, we critically discuss the relationship between RLS/WED and PD by reviewing cross sectional and longitudinal studies, as well as the role of dopamine in these disorders. A twofold interpretation have to be taken into account: dopaminergic therapy may have a crucial role in the development of RLS/WED in PD patients or RLS/WED can be conceived as an early manifestation of PD rather than a risk factor. Several studies showed a high prevalence of RLS/WED in PD patients and several findings related to dopaminergic and iron alterations in both disorders, however up to now it is difficult to find a point of agreement between studies. A greater number of systematic and strongly controlled longitudinal studies as well as basic pathophysiological investigations particularly in RLS/WED are needed to clarify this complex relationship.
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Affiliation(s)
- Luigi Ferini-Strambi
- Department of Clinical Neurosciences, IRCCS San Raffaele Scientific Institute, Neurology - Sleep Disorders Center, Milan, Italy.,Università Vita-Salute San Raffaele, Milan, Italy
| | - Giulia Carli
- Department of Clinical Neurosciences, IRCCS San Raffaele Scientific Institute, Neurology - Sleep Disorders Center, Milan, Italy
| | - Francesca Casoni
- Department of Clinical Neurosciences, IRCCS San Raffaele Scientific Institute, Neurology - Sleep Disorders Center, Milan, Italy
| | - Andrea Galbiati
- Department of Clinical Neurosciences, IRCCS San Raffaele Scientific Institute, Neurology - Sleep Disorders Center, Milan, Italy.,Università Vita-Salute San Raffaele, Milan, Italy
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Hermesdorf M, Sundermann B, Rawal R, Szentkirályi A, Dannlowski U, Berger K. Lack of Association Between Shape and Volume of Subcortical Brain Structures and Restless Legs Syndrome. Front Neurol 2018; 9:355. [PMID: 29867753 PMCID: PMC5968110 DOI: 10.3389/fneur.2018.00355] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 05/01/2018] [Indexed: 11/24/2022] Open
Abstract
Objective Previous studies on patients with restless legs syndrome (RLS) yielded inconclusive results in the magnetic resonance imaging (MRI)-based analyses of alterations of subcortical structures in the brain. The aim of this study was to compare volumes as well as shapes of subcortical structures and the hippocampus between RLS cases and controls. Additionally, the associations between the genetic risks for RLS and subcortical volumes were investigated. Methods We compared volumetric as well as shape differences assessed by 3 T MRI in the caudate nucleus, hippocampus, globus pallidus, putamen, and thalamus in 39 RLS cases versus 117 controls, nested within a population-based sample. In a subsample, we explored associations between known genetic risk markers for RLS and the volumes of the subcortical structures and the hippocampus. Results No significant differences between RLS cases and controls in subcortical and hippocampal shapes and volumes were observed. Furthermore, the genetic risk for RLS was unrelated to any alterations of subcortical and hippocampal gray matter volume. Interpretation We conclude that neither RLS nor the genetic risk for the disease give rise to changes in hippocampal and subcortical shapes and gray matter volumes.
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Affiliation(s)
- Marco Hermesdorf
- Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany
| | - Benedikt Sundermann
- Department of Clinical Radiology, University Hospital Münster, Münster, Germany
| | - Rajesh Rawal
- Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany
| | - András Szentkirályi
- Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany
| | - Udo Dannlowski
- Department of Psychiatry, University of Münster, Münster, Germany
| | - Klaus Berger
- Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany
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Liu C, Wang J, Hou Y, Qi Z, Wang L, Zhan S, Wang R, Wang Y. Mapping the changed hubs and corresponding functional connectivity in idiopathic restless legs syndrome. Sleep Med 2018; 45:132-139. [PMID: 29680421 DOI: 10.1016/j.sleep.2017.12.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 12/19/2017] [Accepted: 12/30/2017] [Indexed: 12/16/2022]
Abstract
OBJECTIVE The hubs of the brain network play a key role in integrating and transferring information between different functional modules. However, whether the changed pattern in functional network hubs contributes to the onset of leg discomfort symptoms in restless legs syndrome (RLS) patients remains unclear. Using resting-state functional magnetic resonance imaging (rs-fMRI) and graph theory methods, we investigated whether alterations of hubs can be detected in RLS. METHODS First, we constructed the whole-brain voxelwise functional connectivity and calculated a functional connectivity strength (FCS) map in each of 16 drug-naive idiopathic RLS patients and 26 gender- and age-matched healthy control (HC) subjects. Next, a two-sample t test was applied to compare the FCS maps between HC and RLS patients, and to identify significant changes in FCS in RLS patients. To further elucidate the corresponding changes in the functional connectivity patterns of the aberrant hubs in RLS patients, whole-brain resting-state functional connectivity analyses for the hub areas were performed. RESULTS The hub analysis revealed decreased FCS in the cuneus, fusiform gyrus, paracentral lobe, and precuneus, and increased FCS in the superior frontal gyrus and thalamus in idiopathic drug-naive RLS patients. Subsequent functional connectivity analyses revealed decreased functional connectivity in sensorimotor and visual processing networks and increased functional connectivity in the affective cognitive network and cerebellar-thalamic circuit. Furthermore, the mean FCS value in the superior frontal gyrus was significantly correlated with Hamilton Anxiety Rating Scale scores in RLS patients, and the mean FCS value in the fusiform gyrus was significantly correlated with Hamilton Depression Rating Scale scores. CONCLUSIONS These findings may provide novel insight into the pathophysiology of RLS.
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Affiliation(s)
- Chunyan Liu
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China; Beijing Key Laboratory of Neuromodulation, Beijing, China
| | - Jiaojian Wang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu, China
| | - Yue Hou
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Zhigang Qi
- Department of Radiology, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Li Wang
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Shuqin Zhan
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Rong Wang
- Central Laboratory, Xuan Wu Hospital, Capital Medical University, Beijing Institute for Brain Disorders, Center of Alzheimer's Disease, Beijing, China; Beijing Geriatric Medical Research Center, Key Laboratory for Neurodegenerative Disease of Ministry of Education, Beijing, China.
| | - Yuping Wang
- Department of Neurology, Xuan Wu Hospital, Capital Medical University, Beijing, China; Beijing Key Laboratory of Neuromodulation, Beijing, China.
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Rizzo G, Plazzi G. Neuroimaging Applications in Restless Legs Syndrome. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2018; 143:31-64. [DOI: 10.1016/bs.irn.2018.09.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Yilmaz O, Şengül Y, Şengül HS, Parlakkaya FB, Öztürk A. Investigation of alexithymia and levels of anxiety and depression among patients with restless legs syndrome. Neuropsychiatr Dis Treat 2018; 14:2207-2214. [PMID: 30214210 PMCID: PMC6120575 DOI: 10.2147/ndt.s174552] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PURPOSE The purpose of this study was to examine alexithymia among restless legs syndrome (RLS) patients, compare with healthy controls, and argue the clinical inferences of this relationship. We searched for anxiety and depression and their clinical outcomes among patients and searched whether the results are similar to previous studies. PATIENTS AND METHODS Eighty-seven RLS patients and 88 age, gender, and educationally matched healthy controls were assessed in Bezmialem Foundation University Hospital. RLS patients and healthy controls were assessed with the Sociodemographic Data Form constructed for the present study, 20-item Toronto Alexithymia Scale (TAS-20), Beck Depression Inventory (BDI), and Beck Anxiety Scale (BAS). The patient group was also assessed with the International Restless Legs Syndrome Study Group (IRLSSG) RLS Severity Scale. RESULTS RLS patients were found to have greater TAS-20, BDI, and BAS scores compared with the control group (P < 0.05). RLS severity score was positively correlated with the scores of anxiety and depression scales. However, no significant relationship was found between scores of IRLSSG RLS scale and TAS-20 total and subscale scores. CONCLUSION RLS patients were found to be more alexithymic than healthy controls, whereas no significant relationship was found between RLS severity and levels of alexithymia. Still, alexithymia might be a predictor for early diagnosis and may be considered in the treatment and follow-up of RLS. RLS patients have higher depression and anxiety scores than healthy individuals. Thus, depression and anxiety should be taken into consideration throughout the RLS treatment.
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Affiliation(s)
- Onur Yilmaz
- Bezmialem Foundation University Medical Faculty, Department of Psychiatry, Istanbul, Turkey,
| | - Yildizhan Şengül
- Bezmialem Foundation University Medical Faculty, Department of Neurology, IIstanbul, Turkey
| | - Hakan Serdar Şengül
- Gaziosmanpaşa Taksim Research and Training Hospital, Department of Psychiatry, Istanbul, Turkey
| | - Fatma Büşra Parlakkaya
- Bezmialem Foundation University Medical Faculty, Department of Psychiatry, Istanbul, Turkey,
| | - Ahmet Öztürk
- Bezmialem Foundation University Medical Faculty, Department of Psychiatry, Istanbul, Turkey,
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Zhuo Y, Wu Y, Xu Y, Lu L, Li T, Wang X, Li K. Combined resting state functional magnetic resonance imaging and diffusion tensor imaging study in patients with idiopathic restless legs syndrome. Sleep Med 2017; 38:96-103. [DOI: 10.1016/j.sleep.2017.06.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/23/2017] [Accepted: 06/27/2017] [Indexed: 11/16/2022]
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Rizzo G, Li X, Galantucci S, Filippi M, Cho YW. Brain imaging and networks in restless legs syndrome. Sleep Med 2016; 31:39-48. [PMID: 27838239 DOI: 10.1016/j.sleep.2016.07.018] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Revised: 07/08/2016] [Accepted: 07/12/2016] [Indexed: 01/18/2023]
Abstract
Several studies provide information useful to our understanding of restless legs syndrome (RLS), using various imaging techniques to investigate different aspects putatively involved in the pathophysiology of RLS, although there are discrepancies between these findings. The majority of magnetic resonance imaging (MRI) studies using iron-sensitive sequences supports the presence of a diffuse, but regionally variable low brain-iron content, mainly at the level of the substantia nigra, but there is increasing evidence of reduced iron levels in the thalamus. Positron emission tomography (PET) and single positron emission computed tomography (SPECT) findings mainly support dysfunction of dopaminergic pathways involving not only the nigrostriatal but also mesolimbic pathways. None or variable brain structural or microstructural abnormalities have been reported in RLS patients; reports are slightly more consistent concerning levels of white matter. Most of the reported changes were in regions belonging to sensorimotor and limbic/nociceptive networks. Functional MRI studies have demonstrated activation or connectivity changes in the same networks. The thalamus, which includes different sensorimotor and limbic/nociceptive networks, appears to have lower iron content, metabolic abnormalities, dopaminergic dysfunction, and changes in activation and functional connectivity. Summarizing these findings, the primary change could be the reduction of brain iron content, which leads to dysfunction of mesolimbic and nigrostriatal dopaminergic pathways, and in turn to a dysregulation of limbic and sensorimotor networks. Future studies in RLS should evaluate the actual causal relationship among these findings, better investigate the role of neurotransmitters other than dopamine, focus on brain networks by connectivity analysis, and test the reversibility of the different imaging findings following therapy.
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Affiliation(s)
- Giovanni Rizzo
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy; Unit of Neurology, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
| | - Xu Li
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA; Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sebastiano Galantucci
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Massimo Filippi
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy; Department of Neurology, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Yong Won Cho
- Department of Neurology, School of Medicine, Dongsan Medical Center, Keimyung University, Daegu, South Korea.
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Koo BB, Bagai K, Walters AS. Restless Legs Syndrome: Current Concepts about Disease Pathophysiology. TREMOR AND OTHER HYPERKINETIC MOVEMENTS (NEW YORK, N.Y.) 2016; 6:401. [PMID: 27536462 PMCID: PMC4961894 DOI: 10.7916/d83j3d2g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 06/07/2016] [Indexed: 01/31/2023]
Abstract
Background In the past few decades, much has been learned about the pathophysiology of restless legs syndrome (RLS). Investigators have studied neuropathology, imaging, electrophysiology, and genetics of RLS, identifying brain regions and biological systems affected in RLS. This manuscript will review RLS pathophysiology literature, examining the RLS state through consideration of the neuroanatomy, then the biological, organ, and genetic systems. Methods Pubmed (1966 to April 2016) was searched for the term “restless legs syndrome” cross-referenced with “pathophysiology,” “pathogenesis,” “pathology,” or “imaging.” English language papers were reviewed. Studies that focused on RLS in relation to another disease were not reviewed. Results Although there are no gross structural brain abnormalities in RLS, widespread brain areas are activated, including the pre- and post-central gyri, cingulate cortex, thalamus, and cerebellum. Pathologically, the most consistent finding is striatal iron deficiency in RLS patients. A host of other biological systems are also altered in RLS, including the dopaminergic, oxygen-sensing, opioid, glutamatergic, and serotonergic systems. Polymorphisms in genes including BTBD9 and MEIS1 are associated with RLS. Discussion RLS is a neurologic sensorimotor disorder that involves pathology, most notably iron deficiency, in motor and sensory brain areas. Brain areas not subserving movement or sensation such as the cingulate cortex and cerebellum are also involved. Other biological systems including the dopaminergic, oxygen-sensing, opioid, glutamatergic, and serotonergic systems are involved. Further research is needed to determine which of these anatomic locations or biological systems are affected primarily, and which are affected in a secondary response.
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Affiliation(s)
- Brian B Koo
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA; Department of Neurology, Connecticut Veterans Affairs Health System, West Haven, CT, USA; Yale Center for Neuroepidemiology & Clinical Neurological Research, New Haven, CT, USA
| | - Kanika Bagai
- Department of Neurology, Vanderbilt University, Nashville, TN, USA
| | - Arthur S Walters
- Department of Neurology, Vanderbilt University, Nashville, TN, USA
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Li X, Allen RP, Earley CJ, Liu H, Cruz TE, Edden RAE, Barker PB, van Zijl PCM. Brain iron deficiency in idiopathic restless legs syndrome measured by quantitative magnetic susceptibility at 7 tesla. Sleep Med 2016; 22:75-82. [PMID: 27544840 PMCID: PMC4992945 DOI: 10.1016/j.sleep.2016.05.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 04/08/2016] [Accepted: 05/07/2016] [Indexed: 12/19/2022]
Abstract
OBJECTIVES Altered brain iron homeostasis with regional iron deficiency has been previously reported in several studies of restless legs syndrome (RLS) patients. Inconsistencies still exist, however, in the reported iron changes in different brain regions and different RLS phenotypes. The purpose of this study was to assess differences in brain iron concentrations between RLS patients and healthy controls and their relation to severity of disease and periodic limb movement during sleep (PLMS). METHODS Assessment of brain iron was done using quantitative magnetic susceptibility measurement, which has been shown to correlate well with the tissue iron content in brain's gray matter. Thirty-nine RLS patients and 29 age-matched healthy controls were scanned at 7 T. Magnetic susceptibilities in substantia nigra (SN), thalamus, striatum, and several iron-rich gray matter regions were quantified and compared with related clinical measures. RESULTS Compared with healthy controls, RLS patients showed significantly decreased magnetic susceptibility in the thalamus and dentate nucleus. No significant difference was found in the SN between RLS patients and healthy controls, but a significant correlation was observed between magnetic susceptibility in SN and the PLMS measure. CONCLUSIONS Using quantitative magnetic susceptibility as an in vivo indicator of brain iron content, the present study supports the general hypothesis of brain iron deficiency in RLS and indicates its possible link to PLMS.
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Affiliation(s)
- Xu Li
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA; Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Richard P Allen
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Christopher J Earley
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Hongjun Liu
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA; Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Radiology, Guangdong Academy of Medical Sciences, Guangdong General Hospital, Guangzhou, China
| | - Tiana E Cruz
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Richard A E Edden
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA; Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Peter B Barker
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA; Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Peter C M van Zijl
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA; Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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