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Weerasekera A, Knight PC, Alshelh Z, Morrissey EJ, Kim M, Zhang Y, Napadow V, Anzolin A, Torrado-Carvajal A, Edwards RR, Ratai EM, Loggia ML. Thalamic neurometabolite alterations in chronic low back pain: a common phenomenon across musculoskeletal pain conditions? Pain 2024; 165:126-134. [PMID: 37578456 PMCID: PMC10841327 DOI: 10.1097/j.pain.0000000000003002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 06/14/2023] [Indexed: 08/15/2023]
Abstract
ABSTRACT Recently, we showed that patients with knee osteoarthritis (KOA) demonstrate alterations in the thalamic concentrations of several metabolites compared with healthy controls: higher myo-inositol (mIns), lower N-acetylaspartate (NAA), and lower choline (Cho). Here, we evaluated whether these metabolite alterations are specific to KOA or could also be observed in patients with a different musculoskeletal condition, such as chronic low back pain (cLBP). Thirty-six patients with cLBP and 20 healthy controls were scanned using 1 H-magnetic resonance spectroscopy (MRS) and a PRESS (Point RESolved Spectroscopy) sequence with voxel placement in the left thalamus. Compared with healthy controls, patients with cLBP demonstrated lower absolute concentrations of NAA ( P = 0.0005) and Cho ( P < 0.05) and higher absolute concentrations of mIns ( P = 0.01) when controlling for age, as predicted by our previous work in KOA. In contrast to our KOA study, mIns levels in this population did not significantly correlate with pain measures (eg, pain severity or duration). However, exploratory analyses revealed that NAA levels in patients were negatively correlated with the severity of sleep disturbance ( P < 0.01), which was higher in patients compared with healthy controls ( P < 0.001). Additionally, also in patients, both Cho and mIns levels were positively correlated with age ( P < 0.01 and P < 0.05, respectively). Altogether, these results suggest that thalamic metabolite changes may be common across etiologically different musculoskeletal chronic pain conditions, including cLBP and KOA, and may relate to symptoms often comorbid with chronic pain, such as sleep disturbance. The functional and clinical significance of these brain changes remains to be fully understood.
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Affiliation(s)
- Akila Weerasekera
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Paulina C. Knight
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Zeynab Alshelh
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Erin J. Morrissey
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Minhae Kim
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
| | - Yi Zhang
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Vitaly Napadow
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Radiology, Harvard Medical School, Boston, MA, USA
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA
| | - Alessandra Anzolin
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Radiology, Harvard Medical School, Boston, MA, USA
- Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA
| | - Angel Torrado-Carvajal
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Radiology, Harvard Medical School, Boston, MA, USA
- Medical Image Analysis and Biometry Laboratory, Universidad Rey Juan Carlos, Madrid, Spain
| | - Robert R. Edwards
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Eva-Maria Ratai
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Marco L. Loggia
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Radiology, Harvard Medical School, Boston, MA, USA
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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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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Park KM, Kim KT, Lee DA, Cho YW. Alterations of the thalamic nuclei volumes and intrinsic thalamic network in patients with restless legs syndrome. Sci Rep 2023; 13:4415. [PMID: 36932255 PMCID: PMC10023689 DOI: 10.1038/s41598-023-31606-8] [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: 07/13/2022] [Accepted: 03/14/2023] [Indexed: 03/19/2023] Open
Abstract
We aimed to investigate the alterations of thalamic nuclei volumes and intrinsic thalamic network in patients with primary restless legs syndrome (RLS) compared to healthy controls. Seventy-one patients with primary RLS and 55 healthy controls were recruited. They underwent brain MRI using a three-tesla MRI scanner, including three-dimensional T1-weighted images. The intrinsic thalamic network was determined using graph theoretical analysis. The right and left whole thalamic volumes, and the right pulvinar inferior, left ventral posterolateral, left medial ventral, and left pulvinar inferior nuclei volumes in the patients with RLS were lower than those in healthy controls (0.433 vs. 0.447%, p = 0.034; 0.482 vs. 0.502%, p = 0.016; 0.013 vs. 0.015%, p = 0.031; 0.062 vs. 0.065%, p = 0.035; 0.001 vs. 0.001%, p = 0.034; 0.018 vs. 0.020%, p = 0.043; respectively). There was also a difference in the intrinsic thalamic network between the groups. The assortative coefficient in patients with RLS was higher than that in healthy controls (0.0318 vs. - 0.0358, p = 0.048). We demonstrated the alterations of thalamic nuclei volumes and intrinsic thalamic network in patients with RLS compared to healthy controls. These changes might be related to RLS pathophysiology and suggest the pivotal role of the thalamus in RLS symptoms.
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Affiliation(s)
- Kang Min Park
- Department of Neurology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - Keun Tae Kim
- Department of Neurology, Keimyung University School of Medicine, 1035 Dalgubeoldae-ro, Dalseo-gu, Daegu, 42601, Korea
| | - Dong Ah Lee
- Department of Neurology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - Yong Won Cho
- Department of Neurology, Keimyung University School of Medicine, 1035 Dalgubeoldae-ro, Dalseo-gu, Daegu, 42601, Korea.
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Evidente VGH, Evidente DH, Ponce FA, Evidente MH, Lambert M, Garrett R. Thalamic Deep Brain Stimulation May Improve Restless Legs Syndrome in Patients With Essential Tremor. Neuromodulation 2021; 25:911-917. [PMID: 34520594 DOI: 10.1111/ner.13532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 07/20/2021] [Accepted: 08/16/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To determine change in restless legs syndrome (RLS) symptoms in essential tremor (ET) patients undergoing bilateral thalamic ventral intermedius (VIM) deep brain stimulation (DBS) surgery. MATERIALS AND METHODS We retrospectively reviewed our database of ET patients with RLS who had undergone VIM DBS for tremor from 2012 to 2020. We reviewed the patients with available International Restless Leg Syndrome Study Group RLS scale scores before and after DBS. Percentage of responders, defined as proportion of patients experiencing three or more point improvement of RLS scores post-DBS, was calculated. We performed two-tailed t-test of pre-DBS and post-DBS RLS scores. RESULTS We identified 13 patients with ET and RLS who had undergone bilateral VIM DBS, of whom nine (69%) were responders post-DBS. Five of 13 patients (38%) had complete resolution of RLS post-DBS. For all patients, mean pre-DBS RLS score was 15.8 ± 7.9 which improved by 46% post-DBS to a mean of 8.5 ± 8.8 (p = 0.007). Four patients rated their RLS scale one night with the stimulator OFF and another night with the stimulator ON. The mean RLS score with stimulator ON was 15.5 ± 7.6 which improved by 53% to a mean of 6.25 ± 7.8 (p = 0.008), with two having complete resolution of RLS with stimulator ON. Of the nine responders, six preferred to keep their stimulator ON at night due to relief of RLS and better subjective quality of sleep. CONCLUSIONS We report for the first time improvement of RLS in patients with ET after bilateral thalamic DBS. Although many ET patients with nonrechargeable DBS systems switch off their stimulator at night to conserve battery life, those with RLS may potentially benefit from keeping their stimulator ON at night to relieve their RLS.
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Affiliation(s)
| | | | | | | | | | - Robin Garrett
- Movement Disorders Center of Arizona, Scottsdale, AZ, USA
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5
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Weerasekera A, Morrissey E, Kim M, Saha A, Lin Y, Alshelh Z, Torrado-Carvajal A, Albrecht D, Akeju O, Kwon YM, Bedair H, Chen AF, Napadow V, Schreiber K, Ratai EM, Edwards RR, Loggia ML. Thalamic neurometabolite alterations in patients with knee osteoarthritis before and after total knee replacement. Pain 2021; 162:2014-2023. [PMID: 33470749 PMCID: PMC8205967 DOI: 10.1097/j.pain.0000000000002198] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 12/02/2020] [Indexed: 12/27/2022]
Abstract
ABSTRACT The weak association between disability levels and "peripheral" (ie, knee) findings suggests that central nervous system alterations may contribute to the pathophysiology of knee osteoarthritis (KOA). Here, we evaluated brain metabolite alterations in patients with KOA, before and after total knee arthroplasty (TKA), using 1H-magnetic resonance spectroscopy (MRS). Thirty-four presurgical patients with KOA and 13 healthy controls were scanned using a PRESS sequence (TE = 30 ms, TR = 1.7 seconds, voxel size = 15 × 15 × 15 mm). In addition, 13 patients were rescanned 4.1 ± 1.6 (mean ± SD) weeks post-TKA. When using creatine (Cr)-normalized levels, presurgical KOA patients demonstrated lower N-acetylaspartate (NAA) (P < 0.001), higher myoinositol (mIns) (P < 0.001), and lower Choline (Cho) (P < 0.05) than healthy controls. The mIns levels were positively correlated with pain severity scores (r = 0.37, P < 0.05). These effects reached statistical significance also using water-referenced concentrations, except for the Cho group differences (P ≥ 0.067). Post-TKA patients demonstrated an increase in NAA (P < 0.01), which returned to the levels of healthy controls (P > 0.05), irrespective of metric. In addition, patients demonstrated postsurgical increases in Cr-normalized (P < 0.001), but not water-referenced mIns, which were proportional to the NAA/Cr increases (r = 0.61, P < 0.05). Because mIns is commonly regarded as a glial marker, our results are suggestive of a possible dual role for neuroinflammation in KOA pain and post-TKA recovery. Moreover, the apparent postsurgical normalization of NAA, a putative marker of neuronal integrity, might implicate mitochondrial dysfunction, rather than neurodegenerative processes, as a plausible pathophysiological mechanism in KOA. More broadly, our results add to a growing body of literature suggesting that some pain-related brain alterations can be reversed after peripheral surgical treatment.
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Affiliation(s)
- Akila Weerasekera
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Erin Morrissey
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Minhae Kim
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Atreyi Saha
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Yang Lin
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Zeynab Alshelh
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Angel Torrado-Carvajal
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
- Medical Image Analysis and Biometry Laboratory, Universidad Rey Juan Carlos, Madrid, Spain
| | - Daniel Albrecht
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Oluwaseun Akeju
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Young-Min Kwon
- Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Hany Bedair
- Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Antonia F Chen
- Department of Orthopaedic Surgery, Brigham and Women's Hospital, Boston, MA, United States
| | - Vitaly Napadow
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Kristin Schreiber
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Eva-Maria Ratai
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Robert R Edwards
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Marco L Loggia
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
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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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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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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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Sigirli D, Gunes A, Turan Ozdemir S, Ercan I, Durmus Y, Erdemli Gursel B. Statistical shape analysis of corpus callosum in restless leg syndrome. Neurol Res 2020; 42:760-766. [PMID: 32496941 DOI: 10.1080/01616412.2020.1773631] [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] [Indexed: 01/18/2023]
Abstract
OBJECTIVES In this study we aimed to investigate corpus callosum shape differences between restless leg syndrome patients and healthy controls, and to determine whether disease severity and duration are indicators for corpus callosum deformation in RLS patients. METHODS This study was conducted using the magnetic resonance imaging scans of 33 restless leg syndrome patients and 33 control subjects. Landmarks were marked on the digital images and callosal landmark coordinate data were used to assess shape difference by performing Generalized Procrustes analysis. The shape deformation from controls to the patients was evaluated performing the Thin Plate Spline approach. RESULTS There was a statistically significant shape difference between the groups. Highest deformation was determined at the posterior midbody of the corpus callosum. Growth curve analyses showed that with the increase in disease duration and severity, the CC size decreased. DISCUSSION The present study demonstrated callosal shape differences in restless leg syndrome using a landmark-based geometric morphometric approach, considering the topographic distribution of corpus callosum for the first time.
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Affiliation(s)
- Deniz Sigirli
- Department of Biostatistics, Medicine, Bursa Uludag University , Bursa, Turkey
| | - Aygul Gunes
- Department of Neurology, Bursa Yuksek Ihtisas Education and Training Hospital, University of Health Sciences , Bursa, Turkey
| | | | - Ilker Ercan
- Department of Biostatistics, Medicine, Bursa Uludag University , Bursa, Turkey
| | - Yavuz Durmus
- Department of Radiology, Bursa Yuksek Ihtisas Education and Training Hospital, University of Health Sciences , Bursa, Turkey
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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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Xu Z, Han T, Li T, Zhang X, Huang Z, Zhan S, Liu C, Xu J, Wang Y. Increased Gray Matter Density and Functional Connectivity of the Pons in Restless Legs Syndrome. Nat Sci Sleep 2020; 12:221-230. [PMID: 32273784 PMCID: PMC7102916 DOI: 10.2147/nss.s239852] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 03/07/2020] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Neurophysiological and radiological studies provide accumulating evidence for the involvement of the brainstem in the pathogenesis of restless legs syndrome (RLS). The analysis of the various subregions of the brainstem may help us better understand the pathophysiological mechanisms underlying the disorder. In this study, we investigated the structural and functional changes in the various subregions of the brainstem in RLS patients. METHODS The subregional changes in gray matter density and functional connectivity in the brainstem were analyzed in 20 drug-naive idiopathic RLS patients, as well as 18 normal control (NC) subjects for comparison. Correlation analyses and multivariate pattern analyses using linear support vector machine (SVM) were conducted. RESULTS We found significantly increased gray matter density in two clusters in the pons (designated pons_1 and pons_2) and in one cluster in the midbrain in RLS patients compared with NC subjects. Further functional connectivity analyses revealed significantly decreased functional connectivity between the midbrain and the right middle occipital gyrus, between pons_1 and the right orbital part of the superior frontal gyrus, and between pons_2 and the right parahippocampus in RLS compared with NC. Moreover, the functional connectivity between pons_2 and the right supplementary motor area (SMA) was significantly increased in RLS compared with NC. This change in RLS was marginally correlated with RS_RLS scores in the RLS patients. SVM-based classification showed an AUC of 0.955 using gray matter density of pons_2, and functional connectivity between pons_2 and SMA as features. CONCLUSION Collectively, our findings suggest that changes in gray matter density and functional connectivity in the pons may play a pathologic role in RLS. Furthermore, these abnormal changes in the pons might help to discriminate RLS from healthy subjects.
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Affiliation(s)
- Zhexue Xu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing 100053, People's Republic of China.,Beijing Key Laboratory of Neuromodulation, Beijing 100053, People's Republic of China
| | - Tao Han
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing 100053, People's Republic of China.,Beijing Key Laboratory of Neuromodulation, Beijing 100053, People's Republic of China
| | - Tian Li
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, People's Republic of China
| | - Xiaodong Zhang
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, People's Republic of China
| | - Zhaoyang Huang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing 100053, People's Republic of China.,Beijing Key Laboratory of Neuromodulation, Beijing 100053, People's Republic of China
| | - Shuqin Zhan
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing 100053, People's Republic of China.,Beijing Key Laboratory of Neuromodulation, Beijing 100053, People's Republic of China
| | - Chunyan Liu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing 100053, People's Republic of China.,Beijing Key Laboratory of Neuromodulation, Beijing 100053, People's Republic of China
| | - Jinping Xu
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, People's Republic of China
| | - Yuping Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing 100053, People's Republic of China.,Beijing Key Laboratory of Neuromodulation, Beijing 100053, People's Republic of China
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12
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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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13
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Cha KS, Kim TJ, Jun JS, Byun JI, Sunwoo JS, Shin JW, Kim KH, Lee SK, Jung KY. Impaired slow oscillation, sleep spindle, and slow oscillation-spindle coordination in patients with idiopathic restless legs syndrome. Sleep Med 2019; 66:139-147. [PMID: 31877505 DOI: 10.1016/j.sleep.2019.09.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/10/2019] [Accepted: 09/16/2019] [Indexed: 10/25/2022]
Abstract
OBJECTIVES Thalamocortical abnormalities have been implicated in the pathophysiology of restless legs syndrome (RLS). We hypothesized that sleep spindle and slow oscillation (SO) activity is impaired in RLS, and that this dysfunction may contribute to sleep disturbance in these patients. To address this issue, we characterized sleep spindle and SO activity in RLS. METHODS Fifteen drug-naive, idiopathic RLS patients (13 female and 2 male) and 15 female healthy controls participated in this study. Nineteen-channel electroencephalograms were obtained during polysomnographic (PSG) recordings. An automated sleep spindle and SO detection algorithm was used to detect sleep spindle (12-16 Hz) and SO (<1 Hz) activity. The quantitative characteristics of sleep spindle and SO activity were investigated. RESULTS Compared with the healthy controls, in RLS patients, we observed density and power reduction in sleep spindles. In SOs, density reduction and duration increment were shown in RLS patients. In addition, SO-spindle coordination was deficient in RLS as revealed by reduced SO locked spindle power, dispersed and delayed spindle phase, and decreased SO-spindle coupling. Although sleep spindle power was negatively correlated with wake after sleep onset (WASO) time, SO duration was positively correlated with the arousal index in RLS. CONCLUSIONS Our study suggests that sleep disturbances may be mediated by a combined deficit in spindle and SO activity and SO-spindle coordination. The abnormal SO and spindle activity observed in RLS support the notion that thalamocortical abnormalities underlie this condition and may promote disturbed sleep integrity.
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Affiliation(s)
- Kwang Su Cha
- Department of Neurology, Seoul National University Hospital, Seoul, South Korea
| | - Tae-Joon Kim
- Department of Neurology, Seoul National University Hospital, Seoul, South Korea; Department of Neurology, Ajou University School of Medicine, Suwon, South Korea
| | - Jin-Sun Jun
- Department of Neurology, Hallym University College of Medicine, Seoul, South Korea
| | - Jung-Ick Byun
- Department of Neurology, Kyung Hee University Hospital at Gangdong, Seoul, South Korea
| | - Jun-Sang Sunwoo
- Department of Neurosurgery, Seoul National University Hospital, Seoul, South Korea
| | - Jung-Won Shin
- Department of Neurology, CHA Bundang Medical Center, CHA University, Seongnam, South Korea
| | - Kyung Hwan Kim
- Department of Biomedical Engineering, College of Health Science, Yonsei University, Wonju, South Korea
| | - Sang Kun Lee
- Department of Neurology, Seoul National University Hospital, Seoul, South Korea; Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Ki-Young Jung
- Department of Neurology, Seoul National University Hospital, Seoul, South Korea; Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea.
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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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15
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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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16
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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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17
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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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18
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Lee BY, Kim J, Connor JR, Podskalny GD, Ryu Y, Yang QX. Involvement of the central somatosensory system in restless legs syndrome. Neurology 2018; 90:e1834-e1841. [DOI: 10.1212/wnl.0000000000005562] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 02/23/2018] [Indexed: 01/18/2023] Open
Abstract
ObjectiveTo investigate morphologic changes in the somatosensory cortex and the thickness of the corpus callosum subdivisions that provide interhemispheric connections between the 2 somatosensory cortical areas.MethodsTwenty-eight patients with severe restless legs syndrome (RLS) symptoms and 51 age-matched healthy controls were examined with high-resolution MRI at 3.0 tesla. The vertex-wise analysis in conjunction with a novel cortical surface classification method was performed to assess the cortical thickness across the whole-brain structures. In addition, the thickness of the midbody of the corpus callosum that links postcentral gyri in the 2 hemispheres was measured.ResultsWe demonstrated that a morphologic change occurred in the brain somatosensory system in patients with RLS compared to controls. Patients with RLS exhibited a 7.5% decrease in average cortical thickness in the bilateral postcentral gyrus (p < 0.0001). Accordingly, there was a substantial decrease in the corpus callosum posterior midbody (p < 0.008) wherein the callosal fibers are connected to the postcentral gyrus, suggesting altered white matter properties in the somatosensory pathway.ConclusionOur results provide in vivo evidence of morphologic changes in the primary somatosensory system, which could be responsible for the sensory functional symptoms of RLS. These results provide a better understanding of the pathophysiology underlying the RLS sensory symptoms and could lead to a potential imaging marker for RLS.
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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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20
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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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21
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Silber MH, Becker PM, Buchfuhrer MJ, Earley CJ, Ondo WG, Walters AS, Winkelman JW. The Appropriate Use of Opioids in the Treatment of Refractory Restless Legs Syndrome. Mayo Clin Proc 2018; 93:59-67. [PMID: 29304922 DOI: 10.1016/j.mayocp.2017.11.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/24/2017] [Accepted: 11/01/2017] [Indexed: 01/18/2023]
Abstract
Restless legs syndrome (RLS) is a distinct disorder, differing from chronic pain in many ways. Refractory RLS is characterized by unresponsiveness to dopamine agonists or alpha-2-delta ligands due to inadequate efficacy, augmentation, or adverse effects. This may result in severely impaired quality of life, profound insomnia, and suicidal depression. Opioid therapy is a mainstay in the management of these patients. This article summarizes the basic science and clinical evidence in support of their use, including the positive result of a large controlled multicenter study of 306 subjects, and outlines an approach to their use in clinical practice. Treatable explanations for RLS refractoriness, such as low iron stores, and other therapeutic options, such as combination therapy, should be considered before prescribing opioids. The agents most commonly used are oxycodone and methadone, but tramadol, codeine, morphine, and hydrocodone can also be considered. Controlled-release medication should be used for evening dosage and short-acting drugs, if needed, during the day. Effective doses are considerably lower than used for chronic pain (oxycodone 10-30 mg daily; methadone 5-20 mg daily) and the risk of opioid use disorder is relatively low. However, sensible precautions should be undertaken, including assessing opioid risk with standard questionnaires, using an opioid contract, using urine drug screens, consulting state prescription drug monitoring programs, and frequent reevaluation of effectiveness and side effects. Opioid use in selected patients with refractory RLS may be life-transforming with favorable risk-benefit ratio.
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Affiliation(s)
- Michael H Silber
- Department of Neurology and Center for Sleep Medicine, Mayo Clinic College of Medicine and Science, Rochester, MN.
| | - Philip M Becker
- Sleep Medicine Associates of Texas and Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Mark J Buchfuhrer
- Department of Psychiatry and Behavioral Science, Stanford School of Medicine, Stanford, CA
| | - Christopher J Earley
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - William G Ondo
- Methodist Research Institute and Department of Neurology, Weill Cornell Medical School, Houston, TX
| | - Arthur S Walters
- Division of Sleep Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - John W Winkelman
- Department of Psychiatry and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
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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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Guo S, Huang J, Jiang H, Han C, Li J, Xu X, Zhang G, Lin Z, Xiong N, Wang T. Restless Legs Syndrome: From Pathophysiology to Clinical Diagnosis and Management. Front Aging Neurosci 2017. [PMID: 28626420 PMCID: PMC5454050 DOI: 10.3389/fnagi.2017.00171] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Restless legs syndrome (RLS), a common neurological sensorimotor disorder in western countries, has gained more and more attention in Asian countries. The prevalence of RLS is higher in older people and females. RLS is most commonly related to iron deficiency, pregnancy and uremia. The RLS symptoms show a significant circadian rhythm and a close relationship to periodic limb movements (PLMs) in clinical observations, while the pathophysiological pathways are still unknown. The diagnostic criteria have been revised in 2012 to improve the validity of RLS diagnosis. Recent studies have suggested an important role of iron decrease of brain in RLS pathophysiology. Dopaminergic (DA) system dysfunction in A11 cell groups has been recognized long ago from clinical treatment and autopsy. Nowadays, it is believed that iron dysfunction can affect DA system from different pathways and opioids have a protective effect on DA system. Several susceptible single nucleotide polymorphisms such as BTBD9 and MEIS1, which are thought to be involved in embryonic neuronal development, have been reported to be associated with RLS. Several pharmacological and non-pharmacological treatment are discussed in this review. First-line treatments of RLS include DA agents and α2δ agonists. Augmentation is very common in long-term treatment of RLS which makes prevention and management of augmentation very important for RLS patients. A combination of different types of medication is effective in preventing and treating augmentation. The knowledge on RLS is still limited, the pathophysiology and better management of RLS remain to be discovered.
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Affiliation(s)
- Shiyi Guo
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan, China
| | - Jinsha Huang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan, China
| | - Haiyang Jiang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan, China
| | - Chao Han
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan, China
| | - Jie Li
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan, China
| | - Xiaoyun Xu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan, China
| | - Guoxin Zhang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan, China
| | - Zhicheng Lin
- Department of Psychiatry, Harvard Medical School, BelmontMA, United States.,Division of Alcohol and Drug Abuse, Mailman Neuroscience Research Center, McLean Hospital, BelmontMA, United States
| | - Nian Xiong
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan, China
| | - Tao Wang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhan, China
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Brain MR Contribution to the Differential Diagnosis of Parkinsonian Syndromes: An Update. PARKINSONS DISEASE 2016; 2016:2983638. [PMID: 27774334 PMCID: PMC5059618 DOI: 10.1155/2016/2983638] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 08/08/2016] [Accepted: 09/01/2016] [Indexed: 12/26/2022]
Abstract
Brain magnetic resonance (MR) represents a useful and feasible tool for the differential diagnosis of Parkinson's disease. Conventional MR may reveal secondary forms of parkinsonism and may show peculiar brain alterations of atypical parkinsonian syndromes. Furthermore, advanced MR techniques, such as morphometric-volumetric analyses, diffusion-weighted imaging, diffusion tensor imaging, tractography, proton MR spectroscopy, and iron-content sensitive imaging, have been used to obtain quantitative parameters useful to increase the diagnostic accuracy. Currently, many MR studies have provided both qualitative and quantitative findings, reflecting the underlying neuropathological pattern of the different degenerative parkinsonian syndromes. Although the variability in the methods and results across the studies limits the conclusion about which technique is the best, specific radiologic phenotypes may be identified. Qualitative/quantitative MR changes in the substantia nigra do not discriminate between different parkinsonisms. In the absence of extranigral abnormalities, the diagnosis of PD is more probable, whereas basal ganglia changes (mainly in the putamen) suggest the diagnosis of an atypical parkinsonian syndrome. In this context, changes in pons, middle cerebellar peduncles, and cerebellum suggest the diagnosis of MSA, in midbrain and superior cerebellar peduncles the diagnosis of PSP, and in whole cerebral hemispheres (mainly in frontoparietal cortex with asymmetric distribution) the diagnosis of Corticobasal Syndrome.
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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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Ku J, Lee YS, Chang H, Earley CJ, Allen RP, Cho YW. Default mode network disturbances in restless legs syndrome/Willis-Ekbom disease. Sleep Med 2016; 23:6-11. [PMID: 27692278 DOI: 10.1016/j.sleep.2016.05.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Revised: 04/10/2016] [Accepted: 05/07/2016] [Indexed: 11/17/2022]
Abstract
BACKGROUND The unusual sensations of restless legs syndrome/Willis-Ekbom disease (RLS/WED) are induced by rest or a low arousal state with a circadian variation in the threshold for induction. It has been suggested that the emergence of RLS/WED symptoms relates to abnormal brain functions dealing with internally generated stimuli. The purpose of this study was to investigate the changes in the default mode network (DMN) in RLS/WED subjects. METHODS Sixteen drug-naïve, idiopathic, RLS/WED subjects, and 16 age-matched and gender-matched healthy subjects were scanned in an asymptomatic resting state. A comparison of the DMN was conducted between the two groups. Resting state functional magnetic resonance imaging (MRI), Korean versions of the International RLS scale, and other sleep questionnaires were used. RESULTS The results showed reductions in the DMN connectivity in the left posterior cingulate cortex, the right orbito-frontal gyrus, the left precuneus, and the right subcallosal gyrus of the RLS/WED subjects. The DMN connectivity was increased in sensory-motor-associated circuits, which included the right superior parietal lobule, the right supplementary motor area, and the left thalamus. In addition, the connectivity between the DMN and thalamus was negatively correlated with that in the orbito-frontal gyrus and the subcallosal gyrus in the subjects. CONCLUSIONS The results showed disturbances of the DMN in RLS/WED subjects that influence the thalamic relay sensory-motor-associated circuit. These findings may underscore the fact that RLS/WED subjects have disturbances in default mode network functions involving internal stimuli in the resting state. This may be related to compensatory changes to maintain resting.
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Affiliation(s)
- Jeonghun Ku
- Department of Biomedical Engineering, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea
| | - Yeong Seon Lee
- Department of Neurology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea
| | - HyukWon Chang
- Department of Radiology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea
| | - Christopher J Earley
- Department of Neurology, Johns Hopkins University, Hopkins Bayview Medical Center, Baltimore, MD, USA
| | - Richard P Allen
- Department of Neurology, Johns Hopkins University, Hopkins Bayview Medical Center, Baltimore, MD, USA
| | - Yong Won Cho
- Department of Neurology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea.
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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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Gorges M, Rosskopf J, Müller HP, Lindemann K, Hornyak M, Kassubek J. Patterns of increased intrinsic functional connectivity in patients with restless legs syndrome are associated with attentional control of sensory inputs. Neurosci Lett 2016; 617:264-9. [PMID: 26921454 DOI: 10.1016/j.neulet.2016.02.043] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 02/22/2016] [Accepted: 02/23/2016] [Indexed: 01/18/2023]
Abstract
INTRODUCTION Potential alterations of intrinsic functional connectivity in idiopathic restless legs syndrome (RLS) are to be assumed since RLS is considered a network disorder. Whole-brain-based investigation of intrinsic functional connectivity networks including the sensorimotor systems in patients with RLS was compared with matched healthy controls. METHODS 'Resting-state' functional MRI (1.5 T) from 26 patients with RLS and 26 matched controls were analyzed using standardized seed-based analysis procedures. The motor/sensorimotor, sensory thalamic, ventral and dorsal attention, basal ganglia-thalamic, cingulate, and brainstem networks were used for voxel-based group comparisons between RLS patients and controls. RESULTS Significantly increased connectivities were observed in the sensory thalamic, ventral and dorsal attention, basal ganglia-thalamic, and cingulate networks in RLS patients, whereas no differences could be demonstrated for the motor/sensorimotor and the brainstem system. The pattern of functional connectivity alterations was positively correlated with increasing symptom severity. CONCLUSIONS Abnormally increased regional BOLD synchronization appears to be a key feature of intrinsic brain architecture in RLS. Alterations in cortical and sub-cortical functional networks support the notion that the underlying pathophysiology of RLS is beyond the sensorimotor and the brainstem system and may be also associated with altered attentional control of sensory inputs.
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Affiliation(s)
- Martin Gorges
- Department of Neurology, University of Ulm, Ulm, Germany
| | | | | | | | - Magdolna Hornyak
- Department of Neurology, University of Ulm, Ulm, Germany; Neuropsychiatry Centre Erding/München, Erding, Germany
| | - Jan Kassubek
- Department of Neurology, University of Ulm, Ulm, Germany.
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Akahoshi M, Ichikawa T, Taura N, Miyaaki H, Yamaguchi T, Yoshimura E, Takahara I, Soyama A, Takatsuki M, Kondo H, Eguchi S, Nakao K. Sleep disturbances and quality of life in patients after living donor liver transplantation. Transplant Proc 2015; 46:3515-22. [PMID: 25498083 DOI: 10.1016/j.transproceed.2014.08.041] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 08/19/2014] [Indexed: 12/21/2022]
Abstract
BACKGROUND Following improvements in patient and graft survival after liver transplantation (LT), the recipients' quality of life has become an important focus of patient care. Sleep is closely related to physical and mental health; however, sleep disturbances in LT patients have not yet been evaluated. METHODS We assessed 59 LT patients (aged ≥18 years) between September 2011 and September 2012. The patients completed the restless legs syndrome (RLS), 36-item short-form health survey (SF-36), Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS) questionnaires. In addition, laboratory data were obtained and neuropsychological tests (NPT) were performed during study entry. RESULTS Thirty-eight patients (64%) were included in the poor sleep group (PSQI ≥6 or ESS ≥10). The SF-36 scores were lower in the poor sleep group than in the good sleep group. Eleven patients (18%) had RLS. An NPT score ≥3 indicated minimal hepatic encephalopathy (MHE3). The MHE3 group consisted of 22 patients (43%). The time after LT was shorter; serum albumin, branched chain amino acid/tyrosine molar ratio (BTR), and role limitations due to poor physical health were lower; and serum ammonia levels were higher in the MHE3 group than in the MHE0-2 group. When the poor sleep group was divided into subgroups (control, MHE, RLS, and unknown), MHE patients had high model for end-stage liver disease scores, high ammonia levels, and low BTR, whereas RLS patients showed a short time after LT. CONCLUSION Sixty-four percent of recipients were classified as poor sleepers. SF-36 scores were lower for poor sleepers than good sleepers. RLS and MHE are major diseases that cause sleep disturbances in patients after LT.
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Affiliation(s)
- M Akahoshi
- Department of Gastroenterology and Hepatology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
| | - T Ichikawa
- Department of Gastroenterology and Hepatology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - N Taura
- Department of Gastroenterology and Hepatology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - H Miyaaki
- Department of Gastroenterology and Hepatology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - T Yamaguchi
- Department of Gastroenterology and Hepatology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - E Yoshimura
- Department of Gastroenterology and Hepatology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - I Takahara
- Department of Gastroenterology and Hepatology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - A Soyama
- Department of Transplantation and Digestive Surgery, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - M Takatsuki
- Department of Transplantation and Digestive Surgery, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - H Kondo
- Center for Sleep Medicine, Saiseikai Nagasaki Hospital, Nagasaki, Japan
| | - S Eguchi
- Department of Transplantation and Digestive Surgery, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - K Nakao
- Department of Gastroenterology and Hepatology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
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Askenasy N, Askenasy JJ. Restless Leg Syndrome in Neurologic and Medical Disorders. Sleep Med Clin 2015; 10:343-50, xv. [DOI: 10.1016/j.jsmc.2015.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Marconi S, Scarlatti F, Rizzo G, Antelmi E, Innamorati M, Pompili M, Brugnoli R, Belvederi Murri M, Amore M, Provini F. Is nocturnal eating in restless legs syndrome linked to a specific psychopathological profile? A pilot study. J Neural Transm (Vienna) 2015; 122:1563-71. [DOI: 10.1007/s00702-015-1435-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 07/24/2015] [Indexed: 10/23/2022]
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Abstract
Neuroimaging studies are of crucial relevance in defining the pathophysiology of restless legs syndrome (RLS). MRI studies showed no structural brain lesions and confirmed a central iron deficiency. Structural and functional studies showed an involvement of the thalamus, sensorimotor cortical areas, and cerebellum in RLS and assessed neurotransmission abnormalities in the dopaminergic and opiate systems. Finally, glutamatergic hyperactivity has been proposed as a cause of disrupted and shortened sleep in RLS. Differences among the results of the studies make it difficult to draw any definitive conclusions, thus, suggesting the need for future research.
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Affiliation(s)
- Federica Provini
- Department of Biomedical and Neuromotor Sciences, Bellaria Hospital, University of Bologna, Via Altura 3, Bologna 40139, Italy; IRCCS Institute of Neurological Sciences of Bologna, Bologna, Italy.
| | - Giacomo Chiaro
- Department of Biomedical and Neuromotor Sciences, Bellaria Hospital, University of Bologna, Via Altura 3, Bologna 40139, Italy
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Upper limb function is normal in patients with restless legs syndrome (Willis-Ekbom Disease). Clin Neurophysiol 2015; 126:736-42. [DOI: 10.1016/j.clinph.2014.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 06/27/2014] [Accepted: 07/07/2014] [Indexed: 11/21/2022]
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An update on restless legs syndrome (Willis-Ekbom disease): clinical features, pathogenesis and treatment. Curr Opin Neurol 2015; 27:493-501. [PMID: 24978636 DOI: 10.1097/wco.0000000000000117] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
PURPOSE OF REVIEW In recent years, there have been a number of advances in the field of restless legs syndrome (RLS) or Willis-Ekbom disease (WED). Here, we review recent studies pertaining to the diagnosis and clinical features, pathogenesis, and treatment of RLS/WED. RECENT FINDINGS Recent studies have added a temporal dimension to RLS/WED epidemiology by examining both the incidence and persistence rates in different populations. Diagnostic criteria have been modified to increase sensitivity, and new guidelines take into account recently published studies of different drug classes. SUMMARY Recent epidemiological findings have shown that RLS/WED is a common neurological disorder that affects up to 5% of the adult population in Western countries. In moderate and severe cases, RLS/WED has a strong impact on sleep and quality of life and can involve an increased cardiovascular risk. Diagnosis is made clinically by confirming the presence of the five essential criteria. However, in difficult cases objective tests such as the multiple suggested immobilization test (m-SIT) can be used. The pathophysiology is partially known, with several risk polymorphisms (BTBD-9 (BTB (POZ) domain containing 9), MEIS-1 (Meis homeobox 1), protein tyrosine phosphatase, receptor type, D, and others) playing an important role, along with dopaminergic and iron dysfunctions. The disorder frequently requires long-term treatment with low-dose dopamine agonists or α2δ ligands. Dopamine agonists are usually effective but the main complication, RLS/WED augmentation, can arise.
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Koo BB. Restless Legs Syndrome: Would You Like That with Movements or Without? Tremor Other Hyperkinet Mov (N Y) 2015; 5:316. [PMID: 26175956 PMCID: PMC4499805 DOI: 10.7916/d80p0z0h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 04/30/2015] [Indexed: 04/24/2023] Open
Abstract
The restless legs syndrome (RLS) is a common sensorimotor condition that often results in discomfort and sleep disturbance. Diagnosis of RLS is entirely clinical and based upon a patient's description of subjective symptoms, and thus when considering RLS diagnosis non-specificity is a real problem. RLS is associated with periodic limb movements during sleep (PLMS) in up to 90% of RLS sufferers; however, their presence is neither sufficient nor necessary for the diagnosis of RLS. The disease RLS and the motor phenomenon of PLMS share similarities in various areas, which include pathophysiology, pharmacology, genetics, and epidemiology. The purpose of this opinion piece is to outline the many similarities between RLS and PLMS in order to make an argument for the inclusion of PLMS as a supplementary diagnostic criterion of RLS, termed electro-clinical RLS, which would consist of the current clinical RLS diagnosis plus PLMS. This additional criterion could be used in cases where diagnosis is unclear to increase specificity or in research projects where proper diagnosis is desired at the investigational level.
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Affiliation(s)
- Brian B. Koo
- Department of Neurology, VA Connecticut Healthcare System, West Haven, Connecticut, USA
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
- To whom correspondence should be addressed. E-mail:
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Guarnieri B, Musicco M, Caffarra P, Adorni F, Appollonio I, Arnaldi D, Bartoli A, Bonanni E, Bonuccelli U, Caltagirone C, Cerroni G, Concari L, Cosentino FII, Fermi S, Ferri R, Gelosa G, Lombardi G, Mearelli S, Nobili F, Passero S, Perri R, Rocchi R, Sucapane P, Tognoni G, Zabberoni S, Sorbi S. Recommendations of the Sleep Study Group of the Italian Dementia Research Association (SINDem) on clinical assessment and management of sleep disorders in individuals with mild cognitive impairment and dementia: a clinical review. Neurol Sci 2014; 35:1329-48. [PMID: 25037740 DOI: 10.1007/s10072-014-1873-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 06/26/2014] [Indexed: 02/02/2023]
Abstract
Clinical assessment and management of sleep disturbances in patients with mild cognitive impairment and dementia has important clinical and social implications. Poor sleep results in an increased risk of morbidities and mortality in demented patients and is a source of stress for caregivers. Sleep disturbances show high prevalence in mild cognitive impairment and dementia patients and they are often associated one to another in the same patient. A careful clinical evaluation of sleep disorders should be performed routinely in the clinical setting of individuals with cognitive decline. The Sleep Study Group of the Italian Dementia Research Association (SINDem) reviewed evidence from original research articles, meta-analyses and systematic reviews published up to December 2013. The evidence was classified in quality levels (I, II, III) and strength of recommendations (A, B, C, D, E). Where there was a lack of evidence, but clear consensus, good practice points were provided. These recommendations may not be appropriate for all circumstances and should therefore be adopted only after a patient's individual characteristics have been carefully evaluated.
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Affiliation(s)
- B Guarnieri
- Center of Sleep Medicine, Villa Serena Hospital, Città S. Angelo, Pescara, Italy,
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Winkelman JW, Schoerning L, Platt S, Jensen JE. Restless legs syndrome and central nervous system gamma-aminobutyric acid: preliminary associations with periodic limb movements in sleep and restless leg syndrome symptom severity. Sleep Med 2014; 15:1225-30. [PMID: 25129262 DOI: 10.1016/j.sleep.2014.05.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 05/06/2014] [Accepted: 05/14/2014] [Indexed: 11/18/2022]
Abstract
BACKGROUND Previous research has demonstrated abnormalities in glutamate and N-acetyl aspartate (NAA) in the thalamus in individuals with restless legs syndrome (RLS) compared with healthy matched controls. However, levels of these transmitters in other RLS-related brain areas and levels of the most common inhibitory neurotransmitter, gamma-aminobutyric acid (GABA), have not been assessed. METHODS This study examined GABA, glutamate, and NAA levels in the dorsal anterior cingulate cortex (ACC), thalamus and cerebellum with the use of proton magnetic resonance spectroscopy ((1)H-MRS) at 4 tesla (4 T) and Megapress difference-editing in 18 subjects with RLS and a matched control group without RLS. Actigraphy was performed on the nights before scans to assess periodic limb movements of sleep (PLMS). RESULTS Levels of GABA, glutamate, and NAA were no different between RLS and control subjects in any of the three voxels of interest. However, GABA levels were positively correlated with both PLM indices and RLS severity in the thalamus and negatively with both of these measures in the cerebellum in RLS subjects. In addition, NAA levels were higher in the ACC in RLS than in controls. CONCLUSION Our preliminary data suggest that known cerebellar-thalamic interactions may modulate the intensity of RLS sensory and motor symptoms. In addition, anterior cingulate cortex may be associated with the affective components of the painful symptoms in this disorder.
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Affiliation(s)
- John W Winkelman
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA; Departments of Psychiatry and Neurology, Sleep Disorders Clinical Research Program, Massachusetts General Hospital, Boston, MA, USA.
| | - Laura Schoerning
- Departments of Psychiatry and Neurology, Sleep Disorders Clinical Research Program, Massachusetts General Hospital, Boston, MA, USA
| | - Sam Platt
- Departments of Psychiatry and Neurology, Sleep Disorders Clinical Research Program, Massachusetts General Hospital, Boston, MA, USA
| | - J Eric Jensen
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA; Brain Imaging Center, McLean Hospital, Boston, MA, USA
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Abstract
PURPOSE OF REVIEW Much recent progress has been made in understanding restless legs syndrome (RLS), focusing mainly on genetic predisposition and dysregulation of iron metabolism and the dopaminergic system. We provide in this review an update of the most recent scientific advances on the pathophysiology of primary RLS. RECENT FINDINGS Genome-wide association studies identified six genetic variants including MEIS1 and BTBD9 with potential relationships with iron. Brain iron level is low in RLS and neuropathological studies have shown significant decreases in dopamine D2 receptors in the putamen that correlated with RLS severity, and increased tyrosine hydroxylase in the substantia nigra. An overly activated dopaminergic system was reported in both animal and cell models of iron insufficiency thus suggesting that in at least a subgroup of RLS patients altered iron metabolism plays a role in the disorder. Also, dysregulation of iron uptake and storage within brain microvessels was recently reported and might play a role in a subgroup of RLS patients. SUMMARY RLS is a genetically heterogeneous complex trait with high prevalence but large phenotype variability. Current theories of RLS pathophysiology emphasize brain iron deficiency with abnormal dopaminergic consequences, together with a strong underlying genetic background.
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40
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Wang Y, Li D, Bao F, Ma S, Guo C, Jin C, Zhang M. Thalamic metabolic alterations with cognitive dysfunction in idiopathic trigeminal neuralgia: a multivoxel spectroscopy study. Neuroradiology 2014; 56:685-93. [PMID: 24820951 DOI: 10.1007/s00234-014-1376-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 05/01/2014] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Although abnormalities in metabolite compositions in the thalamus are well described in patients with idiopathic trigeminal neuralgia (ITN), differences in distinct thalamic subregions have not been measured with proton magnetic resonance spectroscopy ((1)H-MRS), and whether there are correlations between thalamic metabolites and cognitive function still remain unknown. METHODS Multivoxel MRS was recorded to investigate the metabolic alterations in the thalamic subregions of patients with ITN. The regions of interest were localized in the anterior thalamus (A-Th), intralaminar portion of the thalamus (IL-Th), posterior lateral thalamus (PL-Th), posterior medial thalamus (PM-Th), and medial and lateral pulvinar of the thalamus (PuM-Th and PuL-Th). The N-acetylaspartate to creatine (NAA/Cr) and choline to creatine (Cho/Cr) ratios were measured in the ITN and control groups. Scores of the visual analogue scale (VAS) and the Montreal Cognitive Assessment (MoCA) were analyzed to correlate with the neuroradiological findings. RESULTS The NAA/Cr ratio in the affected side of PM-Th and PL-Th in ITN patients was statistically lower than that in the corresponding regions of the thalamus in controls. The NAA/Cr ratio in the affected PM-Th was negatively associated with VAS and disease duration. Furthermore, decreases of NAA/Cr and Cho/Cr were detected in the affected side of IL-Th, and lower Cho/Cr was positively correlated with MoCA values in the ITN group. CONCLUSIONS Our result of low level of NAA/Cr in the affected PM-Th probably serves as a marker of the pain-rating index, and decreased Cho/Cr in IL-Th may be an indicator of cognitive disorder in patients with ITN.
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Affiliation(s)
- Yuan Wang
- Department of Medical Imaging, First Affiliated Hospital of Xi'an Jiaotong University, No. 277, West Yanta Road, Xi'an, Shaanxi, 710061, People's Republic of China
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Yang JS, Cho YJ, Kang SH, Choi HJ. Demographic and clinical characteristics of patients with restless legs syndrome in spine clinic. J Korean Neurosurg Soc 2014; 55:83-8. [PMID: 24653801 PMCID: PMC3958578 DOI: 10.3340/jkns.2014.55.2.83] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 11/19/2013] [Accepted: 01/10/2014] [Indexed: 01/18/2023] Open
Abstract
Objective The restless legs syndrome (RLS) is a common disorder affecting up to 5% to 15% of the general population, in which the incidence increases with age, and includes paresthesia in the legs. The purpose of this study is to investigate the incidence of RLS in spine center and to review clinical manifestations of this syndrome and its current treatments. Methods Over a period of a year, retrospective medical record review and lumbar magnetic resonance images were performed on 32 patients with RLS in spine clinic who were diagnosed by National Institutes of Health criteria. Affected limbs were classified as five. Two grading systems were used in the evaluation of neural compromises. Results The incidence of RLS was 5.00% (32/639). There were 16 males (50%) and 16 females (50%). The median age at diagnosis was 55.4 years (range, 25-93 years). There are no correlation between the affected limbs of RLS and neural compromises on the lumbar spine. Conclusion The RLS is a clearly common neurologic disorder of the limbs, usually the legs. The awareness of this syndrome can help reduce diagnostic error; thereby, avoiding the morbidity and expense associated with unnecessary studies or inappropriate treatments in RLS patients.
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Affiliation(s)
- Jin Seo Yang
- Department of Neurosurgery, Chuncheon Sacred Heart Hospital, College of Medicine, Hallym University, Chuncheon, Korea
| | - Yong Jun Cho
- Department of Neurosurgery, Chuncheon Sacred Heart Hospital, College of Medicine, Hallym University, Chuncheon, Korea
| | - Suk Hyung Kang
- Department of Neurosurgery, Chuncheon Sacred Heart Hospital, College of Medicine, Hallym University, Chuncheon, Korea
| | - Hyuk Jai Choi
- Department of Neurosurgery, Chuncheon Sacred Heart Hospital, College of Medicine, Hallym University, Chuncheon, Korea
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Functional connectivity alternation of the thalamus in restless legs syndrome patients during the asymptomatic period: a resting-state connectivity study using functional magnetic resonance imaging. Sleep Med 2014; 15:289-94. [DOI: 10.1016/j.sleep.2013.09.030] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 09/03/2013] [Accepted: 09/23/2013] [Indexed: 11/18/2022]
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Nocturnal eating is part of the clinical spectrum of restless legs syndrome and an underestimated risk factor for increased body mass index. Sleep Med 2014; 15:168-72. [DOI: 10.1016/j.sleep.2013.08.796] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 07/18/2013] [Accepted: 08/12/2013] [Indexed: 11/18/2022]
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44
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Veauthier C, Paul F. Sleep disorders in multiple sclerosis and their relationship to fatigue. Sleep Med 2014; 15:5-14. [DOI: 10.1016/j.sleep.2013.08.791] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 08/14/2013] [Accepted: 08/20/2013] [Indexed: 10/26/2022]
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45
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Coppola G, Tinelli E, Lepre C, Iacovelli E, Di Lorenzo C, Di Lorenzo G, Serrao M, Pauri F, Fiermonte G, Bianco F, Pierelli F. Dynamic changes in thalamic microstructure of migraine without aura patients: a diffusion tensor magnetic resonance imaging study. Eur J Neurol 2013; 21:287-e13. [DOI: 10.1111/ene.12296] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 09/23/2013] [Indexed: 12/12/2022]
Affiliation(s)
- G. Coppola
- Department of Neurophysiology of Vision and Neurophthalmology; G.B. Bietti Foundation IRCCS; Rome Italy
| | - E. Tinelli
- Neuroradiology Section; Department of Neurology and Psychiatry; ‘Sapienza’ University of Rome; Rome Italy
| | - C. Lepre
- Neurology Section; Department of Medico-Surgical Sciences and Biotechnologies; ‘Sapienza’ University of Rome; Rome Italy
| | - E. Iacovelli
- Neurology Section; Department of Medico-Surgical Sciences and Biotechnologies; ‘Sapienza’ University of Rome; Rome Italy
| | | | - G. Di Lorenzo
- Laboratory of Psychophysiology; Psychiatric Clinic; Department of Systems Medicine; University of Rome ‘Tor Vergata’; Rome Italy
| | - M. Serrao
- Department of Medico-Surgical Sciences and Biotechnologies; ‘Sapienza’ University of Rome Polo Pontino; Latina Italy
| | - F. Pauri
- Neurology Section; Department of Medico-Surgical Sciences and Biotechnologies; ‘Sapienza’ University of Rome; Rome Italy
| | - G. Fiermonte
- Neurology Section; Department of Medico-Surgical Sciences and Biotechnologies; ‘Sapienza’ University of Rome; Rome Italy
| | - F. Bianco
- Neurology Section; Department of Medico-Surgical Sciences and Biotechnologies; ‘Sapienza’ University of Rome; Rome Italy
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46
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Imaging Brain Functional and Metabolic Changes in Restless Legs Syndrome. Curr Neurol Neurosci Rep 2013; 13:372. [DOI: 10.1007/s11910-013-0372-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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47
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Rizzo G, Manners D, Testa C, Tonon C, Vetrugno R, Marconi S, Plazzi G, Pizza F, Provini F, Malucelli E, Gramegna LL, Lodi R. Low brain iron content in idiopathic restless legs syndrome patients detected by phase imaging. Mov Disord 2013; 28:1886-90. [DOI: 10.1002/mds.25576] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 03/29/2013] [Accepted: 05/09/2013] [Indexed: 01/12/2023] Open
Affiliation(s)
- Giovanni Rizzo
- Functional MR Unit; Department of Biomedical and NeuroMotor Sciences (DiBiNeM); University of Bologna; Bologna Italy
- Neurology Unit; Department of Biomedical and NeuroMotor Sciences (DiBiNeM); University of Bologna; Bologna Italy
- “IRCCS Istituto delle Scienze Neurologiche di Bologna,”; Bologna Italy
| | - David Manners
- Functional MR Unit; Department of Biomedical and NeuroMotor Sciences (DiBiNeM); University of Bologna; Bologna Italy
| | - Claudia Testa
- Functional MR Unit; Department of Biomedical and NeuroMotor Sciences (DiBiNeM); University of Bologna; Bologna Italy
| | - Caterina Tonon
- Functional MR Unit; Department of Biomedical and NeuroMotor Sciences (DiBiNeM); University of Bologna; Bologna Italy
| | | | - Sara Marconi
- Neurology Unit; Department of Biomedical and NeuroMotor Sciences (DiBiNeM); University of Bologna; Bologna Italy
- “IRCCS Istituto delle Scienze Neurologiche di Bologna,”; Bologna Italy
| | - Giuseppe Plazzi
- Neurology Unit; Department of Biomedical and NeuroMotor Sciences (DiBiNeM); University of Bologna; Bologna Italy
- “IRCCS Istituto delle Scienze Neurologiche di Bologna,”; Bologna Italy
| | - Fabio Pizza
- Neurology Unit; Department of Biomedical and NeuroMotor Sciences (DiBiNeM); University of Bologna; Bologna Italy
- “IRCCS Istituto delle Scienze Neurologiche di Bologna,”; Bologna Italy
| | - Federica Provini
- Neurology Unit; Department of Biomedical and NeuroMotor Sciences (DiBiNeM); University of Bologna; Bologna Italy
- “IRCCS Istituto delle Scienze Neurologiche di Bologna,”; Bologna Italy
| | - Emil Malucelli
- Department of Pharmacy and Biotechnology; University of Bologna; Bologna Italy
| | - Laura Ludovica Gramegna
- Functional MR Unit; Department of Biomedical and NeuroMotor Sciences (DiBiNeM); University of Bologna; Bologna Italy
| | - Raffaele Lodi
- Functional MR Unit; Department of Biomedical and NeuroMotor Sciences (DiBiNeM); University of Bologna; Bologna Italy
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48
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Millichap JG. Thalamic Metabolism and Restless Legs Syndrome. Pediatr Neurol Briefs 2013. [DOI: 10.15844/pedneurbriefs-27-1-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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