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Tang Y, Shi Y, Xu Z, Hu J, Zhou X, Tan Y, Lan X, Zhou X, Yang J, Zhang J, Deng B, Liu D. Altered gray matter volume and functional connectivity in lung cancer patients with bone metastasis pain. J Neurosci Res 2024; 102. [PMID: 38284835 DOI: 10.1002/jnr.25256] [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: 12/27/2022] [Revised: 09/16/2023] [Accepted: 09/22/2023] [Indexed: 01/30/2024]
Abstract
Bone metastasis pain (BMP) is a severe chronic pain condition. Our previous studies on BMP revealed functional brain abnormalities. However, the potential effect of BMP on brain structure and function, especially gray matter volume (GMV) and related functional networks, have not yet been clearly illustrated. Voxel-based morphometry and functional connectivity (FC) analysis methods were used to investigate GMV and intrinsic FC differences in 45 right-handed lung cancer patients with BMP(+), 37 lung cancer patients without BMP(-), and 45 healthy controls (HCs). Correlation analysis was performed thereafter with all clinical variables by Pearson correlation. Compared to HCs, BMP(+) group exhibited decreased GMV in medial frontal gyrus (MFG) and right middle temporal gyrus (MTG). Compared with BMP(-) group, BMP(+) group exhibited reduced GMV in cerebelum_6_L and left lingual gyrus. However, no regions with significant GMV differences were found between BMP(-) and HCs groups. Receiver operating characteristic analysis indicated the potential classification power of these aberrant regions. Correlation analysis revealed that GMV in the right MTG was positively associated with anxiety in BMP(+) group. Further FC analysis demonstrated enhanced interactions between MFG/right MTG and cerebellum in BMP(+) patients compared with HCs. These results showed that BMP was closely associated with cerebral alterations, which may induce the impairment of pain moderation circuit, deficits in cognitive function, dysfunction of emotional control, and sensorimotor processing. These findings may provide a fresh perspective and further neuroimaging evidence for the possible mechanisms of BMP. Furthermore, the role of the cerebellum in pain processing needs to be further investigated.
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Affiliation(s)
- Yu Tang
- Department of Radiology, Chongqing University Cancer Hospital, School of Medicine, Chongqing University, Chongqing, China
| | - Yumei Shi
- Department of Medical Oncology, Chongqing University Cancer Hospital, School of Medicine Chongqing University, Chongqing, China
| | - Zhen Xu
- Department of Medical Oncology, Chongqing University Cancer Hospital, School of Medicine Chongqing University, Chongqing, China
| | - Junlin Hu
- Department of Medical Oncology, Chongqing University Cancer Hospital, School of Medicine Chongqing University, Chongqing, China
| | - Xueying Zhou
- Department of Medical Oncology, Chongqing University Cancer Hospital, School of Medicine Chongqing University, Chongqing, China
| | - Yong Tan
- Department of Radiology, Chongqing University Cancer Hospital, School of Medicine, Chongqing University, Chongqing, China
| | - Xiaosong Lan
- Department of Radiology, Chongqing University Cancer Hospital, School of Medicine, Chongqing University, Chongqing, China
| | - Xiaoyu Zhou
- Department of Radiology, Chongqing University Cancer Hospital, School of Medicine, Chongqing University, Chongqing, China
| | - Jing Yang
- Department of Radiology, Chongqing University Cancer Hospital, School of Medicine, Chongqing University, Chongqing, China
| | - Jiuquan Zhang
- Department of Radiology, Chongqing University Cancer Hospital, School of Medicine, Chongqing University, Chongqing, China
| | - Benmin Deng
- Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Chongqing University Cancer Hospital, Chongqing, China
| | - Daihong Liu
- Department of Radiology, Chongqing University Cancer Hospital, School of Medicine, Chongqing University, Chongqing, China
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Seok HY, Cho YW. Long-term dopamine agonist treatment fails to restore altered central sensory processing in restless legs syndrome: Evidence from current perception threshold measurements. Sleep Med 2024; 113:1-5. [PMID: 37967484 DOI: 10.1016/j.sleep.2023.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 10/15/2023] [Accepted: 11/03/2023] [Indexed: 11/17/2023]
Abstract
OBJECTIVES Although some studies have examined the impact of short-term dopamine agonist treatment on altered central sensory processing in patients with restless legs syndrome (RLS), there is a scarcity of research investigating the effect of long-term treatment with these drugs. The aim of this study is to investigate the long-term impact of dopamine agonist treatment on altered central sensory processing in RLS patients using current perception threshold (CPT) testing. METHODS We conducted a study of 24 RLS patients, measuring their CPT values before and after dopamine agonist treatment for at least 2 months. Patients were classified as responders or non-responders based on their decrease in International Restless Legs Syndrome (IRLS) score. Clinical parameters were collected and compared pre- and post-treatment. RESULTS The mean duration of treatment with dopamine agonist was 13.6 ± 11.0 months. Our results showed that dopamine agonist treatment significantly improved clinical parameters, including the IRLS score, Visual Analogue Scale, and RLS Quality of Life questionnaire. However, CPT values did not show significant changes for all stimulus frequencies after treatment. Furthermore, we did not find any difference in CPT values before and after treatment in both responders and non-responders. CONCLUSIONS Our study demonstrated that long-term treatment with dopamine agonists effectively reduces RLS symptoms, but does not reverse the altered central sensory processing observed on CPT testing in RLS patients. These results support the notion that the pathophysiology of RLS is multifactorial and not solely driven by dopaminergic dysfunction.
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Affiliation(s)
- Hung Youl Seok
- Department of Neurology, Dongsan Hospital, Keimyung University School of Medicine, Daegu, South Korea
| | - Yong Won Cho
- Department of Neurology, Dongsan Hospital, Keimyung University School of Medicine, Daegu, South Korea.
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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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Zang QL, Zheng JH, Ma JJ, Zhang Q, Huang PP, Shen NN, Miao W. Neuroanatomy and Functional Connectivity in Patients with Parkinson's Disease with or without Restless Legs Syndrome. Neurol Ther 2022; 11:1625-1636. [PMID: 35999489 DOI: 10.1007/s40120-022-00397-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 08/08/2022] [Indexed: 11/30/2022] Open
Abstract
INTRODUCTION Restless legs syndrome (RLS) is a common non-motor symptom in Parkinson's disease (PD), but its pathogenesis remains unclear. This study aimed to explore the potential neural substrates of RLS in a large sample of patients with PD. METHODS A total of 42 patients with PD with RLS and 124 patients with PD without RLS were prospectively recruited at our hospital between February 2019 and October 2020 and underwent structural and resting-state functional magnetic resonance imaging. Differences between the two patient groups were assessed using voxel-based morphometry and functional connectivity analysis. PD duration, Part III of the Movement Disorder Society's Unified Parkinson's Disease Rating Scale (MDS-UPDRS-III) score, and levodopa equivalent daily dose were treated as covariates. RESULTS Patients with PD with RLS had significantly larger gray matter volume in the bilateral posterior cingulate cortex than patients with PD without RLS (FDR-adjusted P < 0.05). Compared to patients without RLS, those with RLS had significantly lower functional connectivity between the left central opercular cortex and the bilateral precentral gyri and postcentral gyri (FDR-adjusted P < 0.001). CONCLUSION Our study provides the first evidence that in patients with PD, RLS is associated with significantly larger gray matter volume in the posterior cingulate cortex and lower resting-state functional connectivity within the sensorimotor network. Our results may help clarify the pathophysiology of RLS in PD and identify possible therapeutic targets.
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Affiliation(s)
- Qiu Ling Zang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, 1 Jian She East Road, Zhengzhou, 450007, Henan Province, People's Republic of China
| | - Jin Hua Zheng
- Department of Neurology, Henan Provincial People's Hospital, No. 7, Weiwu Road, Zhengzhou, 450003, Henan Province, People's Republic of China
| | - Jian Jun Ma
- Department of Neurology, Henan Provincial People's Hospital, No. 7, Weiwu Road, Zhengzhou, 450003, Henan Province, People's Republic of China.
| | - Qi Zhang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, 1 Jian She East Road, Zhengzhou, 450007, Henan Province, People's Republic of China
| | - Pei Pei Huang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, 1 Jian She East Road, Zhengzhou, 450007, Henan Province, People's Republic of China
| | - Nan Nan Shen
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, 1 Jian She East Road, Zhengzhou, 450007, Henan Province, People's Republic of China
| | - Wang Miao
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, 1 Jian She East Road, Zhengzhou, 450007, Henan Province, People's Republic of China.
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Park KM, Kim KT, Lee DA, Cho YW. Structural brain connectivity in patients with restless legs syndrome: a diffusion tensor imaging study. Sleep 2022; 45:6575835. [PMID: 35485481 DOI: 10.1093/sleep/zsac099] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/07/2022] [Indexed: 11/13/2022] Open
Abstract
STUDY OBJECTIVES To evaluate alterations of global and local structural brain connectivity in patients with restless legs syndrome (RLS). METHODS Patients with primary RLS and healthy controls were recruited at a sleep center where they underwent diffusion tensor imaging (DTI) of the brain. We calculated the network measures of global and local structural brain connectivity based on the DTI in both groups using DSI studio program and a graph theory. RESULTS A total of 69 patients with primary RLS and 51 healthy controls were included in the study. We found a significant difference in the global structural connectivity between the groups. The transitivity in the patients with RLS was lower than that in healthy controls (0.031 vs. 0.033, p = 0.035). Additionally, there were significant differences in the local structural connectivity between the groups. The characteristic path length (r = 0.283, p = 0.018), radius of graph (r = 0.260, p = 0.030), and diameter of graph (r = 0.280, p = 0.019) were all positively correlated with RLS severity, whereas the mean clustering coefficient (r = -0.327, p = 0.006), global efficiency (r = -0.272, p = 0.023), small-worldness index (r = -0.325, p = 0.006), and transitivity (r = -0.351, p = 0.003) were negatively correlated with RLS severity. CONCLUSION We identified changes in the global structural connectivity of patients with RLS using graph theory based on DTI, which showed decreased segregation in the brain network compared to healthy controls. These changes are well correlated with RLS severity. We also found changes in local structural connectivity, especially in regions involved in sensorimotor function, which suggests that these areas play a pivotal role in RLS. These findings contribute to a better understanding of the pathophysiology of RLS symptoms.
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Affiliation(s)
- Kang Min Park
- Department of Neurology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, South Korea
| | - Keun Tae Kim
- Department of Neurology, Keimyung University School of Medicine, Daegu, South Korea
| | - Dong Ah Lee
- Department of Neurology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, South Korea
| | - Yong Won Cho
- Department of Neurology, Keimyung University School of Medicine, Daegu, South Korea
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Park KM, Kim KT, Kang KW, Park JA, Seo JG, Kim J, Chang H, Kim EY, Cho YW. Alterations of Functional Connectivity in Patients With Restless Legs Syndrome. J Clin Neurol 2022; 18:290-297. [PMID: 35589318 PMCID: PMC9163943 DOI: 10.3988/jcn.2022.18.3.290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 01/28/2022] [Accepted: 02/03/2022] [Indexed: 11/17/2022] Open
Abstract
Restless legs syndrome (RLS) is a common neurological illness marked by a strong desire to move one’s legs, usually in association with uncomfortable sensations. Recent studies have investigated brain networks and connectivity in RLS. The advent of network analysis has greatly improved our understanding of the brain and various neurological disorders. A few studies have investigated alterations in functional connectivity in patients with RLS. This article reviews functional connectivity studies of patients with RLS, which have identified significant alterations relative to healthy controls in several brain networks including thalamic, salience, default-mode, and small-world networks. In addition, network changes related to RLS treatment have been found, including to repetitive transcranial magnetic stimulation, transcutaneous spinal cord direct-current stimulation, and dopaminergic drugs. These findings suggest that the underlying pathogenesis of RLS includes alterations in the functional connectivity in the brain and that RLS is a network disorder.
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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, Daegu, Korea
| | - Kyung Wook Kang
- Department of Neurology, Chonnam National University Hospital, Gwangju, Korea
| | - Jung A Park
- Department of Neurology, Daegu Catholic University Medical Center, Daegu, Korea
| | - Jong-Geun Seo
- Department of Neurology, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Jiyoung Kim
- Department of Neurology, Pusan National University School of Medicine, Busan, Korea
| | - Hyeyeon Chang
- Department of Neurology, Konyang University School of Medicine, Daejeon, Korea
| | - Eun Young Kim
- Department of Neurology, Chungnam National University Sejong Hospital, Sejong, Korea
| | - Yong Won Cho
- Department of Neurology, Keimyung University School of Medicine, Daegu, Korea.
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Wang XX, Feng Y, Tan EK, Ondo WG, Wu YC. Stroke-related restless legs syndrome: epidemiology, clinical characteristics and pathophysiology. Sleep Med 2022; 90:238-248. [DOI: 10.1016/j.sleep.2022.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/23/2022] [Accepted: 02/01/2022] [Indexed: 12/24/2022]
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Nardone R, Sebastianelli L, Versace V, Orioli A, Saltuari L, Trinka E, Höller Y. Involvement of central sensory pathways in subjects with restless legs syndrome: A neurophysiological study. Brain Res 2021; 1772:147673. [PMID: 34597651 DOI: 10.1016/j.brainres.2021.147673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/14/2021] [Accepted: 09/26/2021] [Indexed: 11/26/2022]
Abstract
In patients with restless legs syndrome (RLS) a motor cortical disinhibition has been reported in transcranial magnetic stimulation (TMS) studies, but the neuronal excitability in other cortical areas has been poorly explored. The aim of this study was the functional evaluation of thalamo-cortical circuits and inhibitory cortical responses in the sensory cortex in RLS. We assessed the high-frequency somatosensory evoked potentials (HF-SEP) in sixteen subjects suffering from RLS of different degrees of severity. In patients with severe or very severe RLS we found a significant desynchronization with amplitude reduction of both pre- and post-synaptic HF-SEP bursts, which suggest an impairment in the thalamo-cortical projections and in the cortical inhibitory interneurons activity, respectively. The assessment of the central sensory pathways by means of HF-SEP may shed light on the pathophysiological mechanisms of RLS.
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Affiliation(s)
- Raffaele Nardone
- Department of Neurology, Hospital of Merano (SABES-ASDAA), Merano-Meran, Italy; Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Spinal Cord Injury and Tissue Regeneration Center, Salzburg, Austria; Karl Landsteiner Institut für Neurorehabilitation und Raumfahrtneurologie, Salzburg, Austria.
| | - Luca Sebastianelli
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Vipiteno-Sterzing, Italy, and Research Department for Neurorehabilitation South Tyrol, Bolzano, Italy
| | - Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Vipiteno-Sterzing, Italy, and Research Department for Neurorehabilitation South Tyrol, Bolzano, Italy
| | - Andrea Orioli
- Department of Neurology, Hospital of Merano (SABES-ASDAA), Merano-Meran, Italy
| | - Leopold Saltuari
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Vipiteno-Sterzing, Italy, and Research Department for Neurorehabilitation South Tyrol, Bolzano, Italy; Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Eugen Trinka
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Centre for Cognitive Neuroscience, Salzburg, Austria; University for Medical Informatics and Health Technology, UMIT, Hall in Tirol, Austria
| | - Yvonne Höller
- Faculty of Psychology, University of Akureyri, Iceland
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White matter tract-specific alterations in patients with primary restless legs syndrome. Sci Rep 2021; 11:16116. [PMID: 34373482 PMCID: PMC8352949 DOI: 10.1038/s41598-021-95238-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 06/22/2021] [Indexed: 01/18/2023] Open
Abstract
Prior diffusion tensor imaging (DTI) studies have investigated white matter (WM) changes in patients with primary restless legs syndrome (RLS), but the results were inconsistent. Here, we proposed using tract-specific statistical analysis (TSSA) to find alterations in specific WM tracts to clarify the pathophysiological mechanisms of RLS. We enrolled 30 patients with RLS and 31 age- and sex- matched controls who underwent brain magnetic resonance imaging, neuropsychological tests, and polysomnography. Fractional anisotropy (FA) maps obtained from whole-brain diffusion tensor imaging and TSSA were used to localize WM changes in patients with RLS. Subsequently, a comparison of FA values for each tract between patients and controls was performed. The associations between FA values and clinical, polysomnographic, and neuropsychological parameters in RLS patients were assessed. RLS patients demonstrated decreased FA values in the left corticospinal tract (CST) and cingulum, and in the right anterior thalamic radiation (ATR) and inferior fronto-occipital fasciculus (IFO). Patients’ attention/executive function and visual memory scores positively correlated with FA values in the right ATR, and anxiety levels negatively correlated with FA values in the right IFO. Additionally, the number of periodic leg movements and movement arousal index were negatively correlated with FA values in the left CST. The TSSA method identified previously unknown tract-specific alterations in patients with RLS and significant associations with distinct clinical manifestations of RLS.
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Wang H, Han X, Jin M, Wang LY, Diao ZL, Guo W, Zhang P, Wang Z, Lv H, Ding HY, Zhang ZY, Zhao PF, Li J, Yang ZH, Liu WH, Wang ZC. Cerebral blood flow alterations in hemodialysis patients with and without restless legs syndrome: an arterial spin labeling study. Brain Imaging Behav 2021; 15:401-409. [PMID: 32700257 DOI: 10.1007/s11682-020-00268-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hemodialysis with restless legs syndrome (HD-RLS) is associated with alterations in neuronal function, the blood-brain barrier and iron deposition, thus affecting cerebral metabolism and perfusion. This study utilized three-dimensional arterial spin labeling (ASL) to identify HD-RLS-related perfusion patterns and potential relationships with disease severity. Twenty-six HD-RLS patients, 30 hemodialysis patients without restless legs syndrome (HD-nRLS) and 30 age-, sex-, and education-matched healthy controls were included in this study. One-way analysis of covariance and post hoc analyses were used to assess differences in cerebral blood flow (CBF) values, demographics and clinical data among the three groups. Pearson's correlation analysis was conducted between altered CBF values in the HD-RLS group and clinical data. Compared with HD-nRLS patients, HD-RLS patients showed increased CBF in the right primary motor cortex (false discovery rate [FDR]-corrected P < 0.05). Compared with the normal controls, both HD subgroups (i.e., those with and without RLS) exhibited consistent CBF changes, including increased CBF in the left medial superior frontal gyrus and bilateral thalamus and decreased CBF in the left insular cortices (FDR-corrected P < 0.05). This abnormal hyperperfusion in the sensorimotor cortex and basal ganglia provides evidence for a sensory processing disorder in RLS that may be involved in the pathogenesis of RLS in HD patients.
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Affiliation(s)
- Hao Wang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China
| | - Xue Han
- Department of Nephrology, Faculty of Kidney Diseases, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China
| | - Mei Jin
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China
| | - Li-Yan Wang
- Department of Nephrology, Faculty of Kidney Diseases, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China
| | - Zong-Li Diao
- Department of Nephrology, Faculty of Kidney Diseases, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China
| | - Wang Guo
- Department of Nephrology, Faculty of Kidney Diseases, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China
| | - Peng Zhang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China
| | - Zheng Wang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China
| | - Han Lv
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China
| | - He-Yu Ding
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China
| | - Zheng-Yu Zhang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China
| | - Peng-Fei Zhao
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China
| | - Jing Li
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China
| | - Zheng-Han Yang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China
| | - Wen-Hu Liu
- Department of Nephrology, Faculty of Kidney Diseases, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China.
| | - Zhen-Chang Wang
- Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing, 100050, China.
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12
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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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13
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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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14
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de Paiva JPQ, Magalhães SC, Moura LM, Sato JR, Amaro E, Sterr A, Schlaffke L, Eckeli AL, do Prado GF, Conforto AB. Sensorimotor white matter projections and disease severity in primary Restless Legs Syndrome/Willis-Ekbom disease: a multimodal DTI analysis. Sleep Med 2020; 73:106-116. [PMID: 32805477 DOI: 10.1016/j.sleep.2020.05.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/22/2020] [Accepted: 05/26/2020] [Indexed: 01/18/2023]
Abstract
BACKGROUND Restless Legs Syndrome, a potentially disabling sleep disorder, also known as Willis-Ekbom disease (RLS/WED), may be caused by loss of inhibitory modulation of descending central motor pathways, structural changes in the somatosensory cortex, abnormal connectivity between motor and sensory areas, as well as by subtle abnormalities in white matter micro-organization. OBJECTIVE To compare diffusion-tensor imaging (DTI) metrics in areas associated with sensory or motor function, as well as sensorimotor integration, between subjects with primary mild-to-severe RLS/WED and controls. METHODS DTI metrics were assessed in 38 subjects with RLS/WED (14 mild to moderate, 24 severe to very severe) and 24 healthy age-matched controls with whole-brain Tract Based Spatial Statistics (TBSS), Region-of-interest (ROI) and probabilistic tractography based analyses. The ROIs corresponded to the corticospinal tract (CST) at the level of the cerebral peduncle; the superior, middle and inferior cerebellar peduncles. Subgroup analyses were made according to the severity of RLS/WED symptoms. The corticospinal tract was evaluated with probabilistic tractography. We also explored associations between significant findings and severity of symptoms with the Spearman's correlation coefficient. RESULTS TBSS analysis revealed decreased axial diffusivity (AD) in the left posterior thalamic radiation in RLS/WED. In subjects with severe RLS/WED, AD was reduced in the left posterior corona radiata and this reduction was negatively correlated with severity of symptoms. ROI-based analysis showed that radial diffusivity (RD) was increased in the superior cerebellar peduncles of individuals with severe RLS/WED. Tractography did not show between-group or subgroup differences. CONCLUSIONS Our results are consistent with subtle white matter changes, prominently in RLS/WED subjects with more severe symptoms, in areas related to sensory or motor function, as well as to sensorimotor integration, compared to controls. These findings support the hypothesis, raised by prior pathophysiological studies, of defective integration within these networks.
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Affiliation(s)
- Joselisa Péres Queiroz de Paiva
- Brain Institute, Hospital Israelita Albert Einstein (HIAE), São Paulo, SP, Brazil; Imaging Research Center, Hospital Israelita Albert Einstein (HIAE), São Paulo, SP, Brazil.
| | - Samir Câmara Magalhães
- Brain Institute, Hospital Israelita Albert Einstein (HIAE), São Paulo, SP, Brazil; Universidade de Fortaleza (UNIFOR), Unifor, Fortaleza, CE, Brazil
| | - Luciana Monteiro Moura
- Imaging Research Center, Hospital Israelita Albert Einstein (HIAE), São Paulo, SP, Brazil
| | - João Ricardo Sato
- Center for Mathematics, Computing and Cognition, Universidade Federal do ABC (UFABC), São Bernardo do Campo, SP, Brazil
| | - Edson Amaro
- Brain Institute, Hospital Israelita Albert Einstein (HIAE), São Paulo, SP, Brazil; Imaging Research Center, Hospital Israelita Albert Einstein (HIAE), São Paulo, SP, Brazil; Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil
| | - Annette Sterr
- School of Psychology, University of Surrey, Guildford, UK
| | - Lara Schlaffke
- Department of Neurology, BG University Clinic Bergmannsheil, Ruhr-University Bochum, Bochum, Germany
| | - Alan Luiz Eckeli
- Department of Neurosciences and Behavioral Sciences, Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | - Adriana Bastos Conforto
- Brain Institute, Hospital Israelita Albert Einstein (HIAE), São Paulo, SP, Brazil; Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil
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15
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Ku J, Lee YS, Kim KT, Chang H, Cho YW. Alterations in Salience Network Functional Connectivity in Individuals with Restless Legs Syndrome. Sci Rep 2020; 10:7643. [PMID: 32377013 PMCID: PMC7203171 DOI: 10.1038/s41598-020-64641-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 04/20/2020] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Restless legs syndrome (RLS) is a neurological disorder which is most commonly identified by an urge to move the legs. It often shows alterations in sensory processing which implies the salience network (SN) is experiencing changes. This study investigates the functional connectivity (FC) between the SN and other areas of the brain in RLS patients during the resting state period. METHODS Thirty patients with drug naïve idiopathic RLS and 30 healthy age and gender matched controls were included in this study. Resting state fMRIs were performed in the morning during the asymptomatic period. The SN comparisons were conducted between the two groups. RESULTS The RLS group showed a reduction in SN FC in the right pyramis, and an increase in SN FC in the bilateral orbitofrontal gyri and right postcentral gyrus. CONCLUSIONS The results of this study give reason to believe that SN FC in RLS patients is altered during asymptomatic periods. This could have an influence on the processing of the saliency of information, particularly sensory information processing and inhibition mechanisms.
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Affiliation(s)
- Jeonghun Ku
- Department of Biomedical Engineering, Keimyung University School of Medicine, Dongsan Medical Center, Daegu, South Korea
| | - Yeong Seon Lee
- Department of Neurology, Keimyung University School of Medicine, Dongsan Medical Center, Daegu, South Korea
| | - Keun Tae Kim
- Department of Neurology, Keimyung University School of Medicine, Dongsan Medical Center, Daegu, South Korea
| | - HyukWon Chang
- Department of Radiology, Keimyung University School of Medicine, Dongsan Medical Center, Daegu, South Korea
| | - Yong Won Cho
- Department of Neurology, Keimyung University School of Medicine, Dongsan Medical Center, Daegu, South Korea.
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16
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Weinstock LB, Walters AS, Brook JB, Kaleem Z, Afrin LB, Molderings GJ. Restless legs syndrome is associated with mast cell activation syndrome. J Clin Sleep Med 2020; 16:401-408. [PMID: 31994488 DOI: 10.5664/jcsm.8216] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
STUDY OBJECTIVES Mast cell activation syndrome (MCAS) is an inflammatory and allergic disorder. We determined the prevalence of restless legs syndrome (RLS) in MCAS because each common syndrome may be inflammatory in nature and associated with dysautonomia. METHODS Individuals with MCAS were evaluated for RLS by two standard questionnaires. Prevalence comparisons included spouse control patients and two prevalence publications. MCAS diagnosis required mast cell (MC) symptoms in ≥ 2 organs plus ≥ 1 elevated MC mediators, improvement with MC therapy, and/or increased intestinal MC density. Clinical variables were studied. RESULTS There were 174 patients with MCAS (146 female, 28 male, mean age 44.8 years) and 85 spouse control patients (12 female, 73 male, mean age 50.9 years). Patients with MCAS as a whole had a higher prevalence of RLS (40.8%) than spouse control (12.9%) (P < .0001) Male patients with MCAS had a higher prevalence of RLS (32.1%) than male controls (12.3%, odds ratio [OR] 3.4, confidence interval [CI] 1.2-9.7, P = .025), American men (8.4%, OR 5.2, CI 2.2-12.0, P < .001), and French men (5.8%, OR 7.7, CI 3.4-17.1, P < .001). Female patients with MCAS also had a higher prevalence of RLS (42.5%) than female controls (16.7%) but this did not reach statistical significance perhaps because of the sample size of the female controls. However, female patients with MCAS had a statistically higher prevalence of RLS than American women (10.0%, OR 6.7, CI 4.5-9.7, P < .0001) and French women (10.8%, OR 6.1, CI 4.4-8.6, P < .0001). CONCLUSIONS RLS appears to be associated with MCAS. Effects of mast cell mediators, inflammation, immune mechanisms, dysautonomia, or hypoxia may theoretically activate RLS in MCAS.
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Affiliation(s)
- Leonard B Weinstock
- Washington University School of Medicine, Specialists in Gastroenterology, LLC, St. Louis, Missouri
| | - Arthur S Walters
- Division of Sleep Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | | | - Zahid Kaleem
- Specialists in Gastroenterology, LLC, St. Louis, Missouri
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17
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Resting-state connectivity and the effects of treatment in restless legs syndrome. Sleep Med 2019; 67:33-38. [PMID: 31887606 DOI: 10.1016/j.sleep.2019.10.014] [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: 06/15/2019] [Revised: 10/05/2019] [Accepted: 10/14/2019] [Indexed: 01/25/2023]
Abstract
OBJECTIVES Resting-state brain connectivity has been shown to differ for Restless Legs Syndrome (RLS) compared to healthy control (CON) groups. This study evaluates the degree these RLS-CON differences are changed by concurrent treatment. METHODS Resting-state functional MRIs were obtained from 32 idiopathic RLS patients during the morning asymptomatic period and 16 age and gender-matched CON subjects. Of the 32 RLS patients, 16 were drug-naïve (DN-RLS), and 16 were regularly drug-treated using a dopamine agonist (DT-RLS). Various assessments of disease characteristics were also performed. The primary purpose was to assess the replicability of prior results and the effects of treatment on these differences between controls and untreated RLS patients. Resting-state connectivity was analyzed by a seed-based method using the bilateral ventral-posterolateral nuclei (VPLN) in the thalamus. RESULTS In the DN-RLS group, compared to the CON group, three areas (the bilateral lingual gyri and right middle temporal gyrus) were replicated. The three replicated areas did not significantly differ for DT-RLS compared to DN-RLS. DT-RLS compared to DN-RLS had significantly higher thalamic connectivity for the left uvula, right tuber, left anterior insula, and right declive. CONCLUSIONS Thalamic connectivity to the bilateral lingual gyri and right middle temporal gyrus is a replicable finding in DN-RLS that was not affected by dopamine agonist treatments. Other changes in thalamic connectivity were altered by dopamine agonist treatment. These treatment effects may be pertinent to the known treatment benefits of a dopamine agonist on RLS symptoms.
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18
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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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19
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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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20
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Sleep disturbances and gastrointestinal dysfunction are associated with thalamic atrophy in Parkinson's disease. BMC Neurosci 2019; 20:55. [PMID: 31640554 PMCID: PMC6805461 DOI: 10.1186/s12868-019-0537-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 10/12/2019] [Indexed: 01/18/2023] Open
Abstract
Background Non-motor symptoms are common aspects of Parkinson’s disease (PD) occurring even at the prodromal stage of the disease and greatly affecting the quality of life. Here, we investigated whether non-motor symptoms burden was associated with cortical thickness and subcortical nuclei volume in PD patients. Methods We studied 41 non-demented PD patients. Non-motor symptoms burden was assessed using the Non-Motor Symptoms Scale grading (NMSS). Cortical thickness and subcortical nuclei volume analyses were carried out using Free-Surfer. PD patients were divided into two groups according to the NMSS grading: mild to moderate (NMSS: 0–40) and severe (NMSS: ≥ 41) non-motor symptoms. Results Thalamic atrophy was associated with higher NMSQ and NMSS total scores. The non-motor symptoms that drove this correlation were sleep/fatigue and gastrointestinal tract dysfunction. We also found that PD patients with severe non-motor symptoms had significant thalamic atrophy compared to the group with mild to moderate non-motor symptoms. Conclusions Our findings show that greater non-motor symptom burden is associated with thalamic atrophy in PD. Thalamus plays an important role in processing sensory information including visceral afferent from the gastrointestinal tract and in regulating states of sleep and wakefulness.
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21
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Li Z, Chen J, Lin Y, Zhou M, Cai Q, Li X, Wu Z, Chen X, Yang X, Zhu X, Lu J, Zhang L, Liu B, Luo X, Xu P. Reduced regional activity and functional connectivity within sensorimotor network in Parkinson's patients with restless legs syndrome. Mol Pain 2019; 15:1744806919882272. [PMID: 31554460 DOI: 10.1177/1744806919882272] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Affiliation(s)
- Zhe Li
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jun Chen
- Department of Radiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yuwan Lin
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Miaomiao Zhou
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Qiaodi Cai
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xinchun Li
- Department of Radiology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Zhuohua Wu
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xinjie Chen
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xinling Yang
- Department of Neurology, The Second Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Xiaoqin Zhu
- Department of Physiology, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Jianjun Lu
- Department of Neurosurgery, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Li Zhang
- Department of Geriatrics, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
| | - Bo Liu
- Department of Radiology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xiaodong Luo
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Pingyi Xu
- Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Department of Physiology, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
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22
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Magalhães SC, Queiroz de Paiva JP, Kaelin-Lang A, Sterr A, Eckeli AL, Winkler AM, Fernandes do Prado G, Amaro E, Conforto AB. Short-interval intracortical inhibition is decreased in restless legs syndrome across a range of severity. Sleep Med 2019; 62:34-42. [PMID: 31539846 DOI: 10.1016/j.sleep.2019.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 03/10/2019] [Accepted: 03/12/2019] [Indexed: 01/18/2023]
Abstract
BACKGROUND Decreased short-interval intracortical inhibition (SICI) to transcranial magnetic stimulation (TMS) of the primary motor cortex was described in subjects with restless legs syndrome/Willis-Ekbom disease (RLS/WED). It remained to be determined whether the magnitude of SICI decrease would be similar across levels of RLS/WED severity. Moreover, it was unknown whether, in addition to decreases in SICI, changes in cortical thickness or area could be detected in subjects with RLS/WED compared to controls. The objective of this study was to compare SICI, cortical thickness, and cortical area in subjects with idiopathic mild to moderate RLS/WED, severe to very severe RLS/WED, and controls. METHODS The severity of RLS/WED was assessed by the International Restless Legs Syndrome Severity Scale (IRLSS). SICI and 3T magnetic resonance imaging (MRI) data of subjects with RLS/WED and controls were compared. A receiver operating characteristic curve for SICI was designed for discrimination of participants with RLS/WED from controls. Cortical thickness and area were assessed by automated surface-based analysis. RESULTS SICI was significantly reduced in patients with mild to moderate and severe to very severe RLS/WED, compared to controls (one-way analysis of variance: F = 9.62, p < 0.001). Receiver operating characteristic curve analysis predicted RLS/WED when SICI was above 35% (area under the curve = 0.79, 95% CI 0.67-0.91, p < 0.001). Analyses of the whole brain and of regions of interest did not reveal differences in gray matter thickness or area between controls and subjects with RLS/WED. CONCLUSION SICI is an accurate cortical biomarker that can support the diagnosis of RLS/WED even in subjects with mild symptoms, but cortical thickness and area were not useful for discriminating subjects with this condition from controls.
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Affiliation(s)
- Samir Câmara Magalhães
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil; Universidade de Fortaleza, Unifor, Fortaleza, CE, Brazil.
| | | | | | - Annette Sterr
- Department of Psychology, University of Surrey, Guildford, Surrey, UK
| | - Alan Luiz Eckeli
- Departamento de Neurociências e Ciências do Comportamento, Divisão de Neurologia, Hospital das Clínicas da Faculdade de Medicina da USP-Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | | | | | - Edson Amaro
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil; Departamento de Radiologia, Hospital das Clínicas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Adriana Bastos Conforto
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil; Departamento de Neurologia, Hospital das Clínicas, Universidade de São Paulo, São Paulo, SP, Brazil
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Seok HY, Do SY, Motamedi GK, Cho YW. Symptom‐related changes in current perception threshold of restless legs syndrome. J Sleep Res 2019; 29:e12890. [DOI: 10.1111/jsr.12890] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 05/16/2019] [Accepted: 06/02/2019] [Indexed: 12/24/2022]
Affiliation(s)
- Hung Youl Seok
- Department of Neurology Dongsan Medical Center School of Medicine Keimyung University Daegu Republic of Korea
| | - So Young Do
- Department of Neurology Dongsan Medical Center School of Medicine Keimyung University Daegu Republic of Korea
| | - Gholam K. Motamedi
- Department of Neurology Georgetown University Hospital Washington DC USA
| | - Yong Won Cho
- Department of Neurology Dongsan Medical Center School of Medicine Keimyung University Daegu Republic of 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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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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26
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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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Li G, Tang H, Chen J, Qi X, Chen S, Ma J. Executive and Visuospatial Dysfunction in Patients With Primary Restless Legs Syndrome/Willis-Ekbom Disease: Study of a Chinese Population. J Clin Sleep Med 2018; 14:785-790. [PMID: 29734979 DOI: 10.5664/jcsm.7106] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 01/26/2018] [Indexed: 01/12/2023]
Abstract
STUDY OBJECTIVES The aim of the study was to investigate the cognitive function of patients with primary restless legs syndrome/Willis-Ekbom disease (RLS/ WED) in a Chinese population. METHODS A total of 40 patients with RLS/WED who were drug naïve and 40 controls, matched by age, sex, and educational level, were evaluated by cognitive function assessments, including the Chinese version of the Mini-Mental State Examination (MMSE-C), clock drawing test (CDT), Auditory Verbal Learning Test (AVLT), Rey-Osterrieth Complex Figure Test (CFT), and Stroop Color Word Test (SCWT). RESULTS Patients with RLS/WED showed worse performance on the SCWT (Stroop Card C time: 102.36 ± 17.12 versus 87.08 ± 7.73 seconds, P = .033; Interference Index: 3.39 ± 0.38 versus 2.90 ± 0.15, P < .0001), CFT (24.05 ± 9.28 versus 33.74 ± 1.59, P = .008), and CDT than controls (16-score method: 10.13 ± 3.94 versus 13.98 ± 1.79, P = .0002) after adjusting for Hamilton Anxiety Scale score, Hamilton Depression Scale score, Epworth Sleepiness Scale score, and Pittsburgh Sleep Quality Index total score to eliminate the confounders of concomitant sleep disturbances, anxiety, and depression. CONCLUSIONS Our study suggested that cognitive functions involving executive and visuospatial domains might be disturbed in Chinese patients with primary RLS/WED.
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Affiliation(s)
- Gen Li
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; *contributed equally
| | - Huidong Tang
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; *contributed equally
| | - Jie Chen
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; *contributed equally
| | - Xuemei Qi
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; *contributed equally
| | - Shengdi Chen
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; *contributed equally
| | - Jianfang Ma
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; *contributed equally
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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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Affiliation(s)
- Tadaaki Mano
- From the Gifu University of Medical Science (T.M.), Seki, Gifu, Japan; and Division of Pulmonary, Critical Care & Sleep (R.J.T.), Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA.
| | - Robert J Thomas
- From the Gifu University of Medical Science (T.M.), Seki, Gifu, Japan; and Division of Pulmonary, Critical Care & Sleep (R.J.T.), Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
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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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Yang FC, Chou KH, Hsu AL, Fuh JL, Lirng JF, Kao HW, Lin CP, Wang SJ. Altered Brain Functional Connectome in Migraine with and without Restless Legs Syndrome: A Resting-State Functional MRI Study. Front Neurol 2018; 9:25. [PMID: 29441041 PMCID: PMC5797592 DOI: 10.3389/fneur.2018.00025] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 01/12/2018] [Indexed: 01/03/2023] Open
Abstract
Background Migraine is frequently comorbid with restless legs syndrome (RLS), both displaying functional connectivity (FC) alterations in multiple brain networks, although the neurological basis of this association is unknown. Methods We performed resting-state functional magnetic resonance imaging and network-wise analysis of FC in migraine patients with and without RLS and healthy controls (CRL). Network-based statistics (NBS) and composite FC matrix analyses were performed to identify the patterns of FC changes. Correlation analyses were performed to identify associations between alterations in FC and clinical profiles. Results NBS results revealed that both migraine patients with and without RLS exhibited lower FC than CRL in the dorsal attention, salience, default mode, cingulo-opercular, visual, frontoparietal, auditory, and sensory/somatomotor networks. Further composite FC matrix analyses revealed differences in FC of the salience, default mode to subcortical and frontoparietal, auditory to salience, and memory retrieval networks between migraine patients with and without RLS. There was a trend toward a negative association between RLS severity and cross-network abnormalities in the default mode to subcortical network. Discussion Migraine patients with and without RLS exhibit disruptions of brain FC. Such findings suggest that these disorders are associated with differential neuropathological mechanisms and may aid in the future development of neuroimaging-driven biomarkers for these conditions.
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Affiliation(s)
- Fu-Chi Yang
- Department of Neurology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.,Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Kun-Hsien Chou
- Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Ai-Ling Hsu
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
| | - Jong-Ling Fuh
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan.,Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Jiing-Feng Lirng
- Department of Radiology, National Yang-Ming University, Taipei, Taiwan.,Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Hung-Wen Kao
- Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Ching-Po Lin
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan.,Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Shuu-Jiun Wang
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan.,Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan.,Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
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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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Ku J, Lee YS, Chang HW, Earley CJ, Allen RP, Cho YW. Diurnal variation of default mode network in patients with restless legs syndrome. Sleep Med 2018; 41:1-8. [DOI: 10.1016/j.sleep.2017.09.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 08/16/2017] [Accepted: 09/20/2017] [Indexed: 01/22/2023]
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34
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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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Cogez J, Ribeiro E, de La Sayette V, Viader F. Complete recovery of restless legs syndrome after unilateral thalamic and tegmental infarction: A case report. J Clin Neurosci 2017; 44:229-230. [DOI: 10.1016/j.jocn.2017.06.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 06/12/2017] [Indexed: 10/19/2022]
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36
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Lanza G, Bachmann CG, Ghorayeb I, Wang Y, Ferri R, Paulus W. Central and peripheral nervous system excitability in restless legs syndrome. Sleep Med 2017; 31:49-60. [PMID: 27745789 DOI: 10.1016/j.sleep.2016.05.010] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 05/24/2016] [Accepted: 05/30/2016] [Indexed: 02/07/2023]
Abstract
Neurophysiological techniques have been applied in restless legs syndrome (RLS) to obtain direct and indirect measures of central and peripheral nervous system excitability, as well as to probe different neurotransmission pathways. Data converge on the hypothesis that, from a pure electrophysiological perspective, RLS should be regarded as a complex sensorimotor disorder in which cortical, subcortical, spinal cord, and peripheral nerve generators are all involved in a network disorder, resulting in an enhanced excitability and/or decreased inhibition. Although the spinal component may have dominated in neurophysiological assessment, possibly because of better accessibility compared to the brainstem or cerebral components of a hypothetical dysfunction of the diencephalic A11 area, multiple mechanisms, such as reduced central inhibition and abnormal peripheral nerve function, contribute to the pathogenesis of RLS similarly to some chronic pain conditions. Dopamine transmission dysfunction, either primary or triggered by low iron and ferritin concentrations, may also bridge the gap between RLS and chronic pain entities. Further support of disturbed central and peripheral excitability in RLS is provided by the effectiveness of nonpharmacological tools, such as repetitive transcranial magnetic stimulation and transcutaneous spinal direct current stimulation, in transiently modulating neural excitability, thereby extending the therapeutic repertoire. Understanding the complex interaction of central and peripheral neuronal circuits in generating the symptoms of RLS is mandatory for a better refinement of its therapeutic support.
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Affiliation(s)
- Giuseppe Lanza
- Sleep Research Center, I.R.C.C.S. "Oasi Maria SS.", Troina, Italy.
| | | | - Imad Ghorayeb
- Department of Clinical Neurophysiology, CHU de Bordeaux, Bordeaux, France; CNRS, INCIA, CNRS UMR 5287, Université de Bordeaux, Bordeaux, France
| | - Yuping Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Raffale Ferri
- Sleep Research Center, I.R.C.C.S. "Oasi Maria SS.", Troina, Italy
| | - Walter Paulus
- Department of Clinical Neurophysiology, University Medical Center, Georg August University Göttingen, Göttingen, Germany
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Cho YW, Kang MS, Kim KT, Do SY, Lim JG, Lee SY, Motamedi GK. Quantitative sensory test for primary restless legs syndrome/Willis–Ekbom disease using the current perception threshold test. Sleep Med 2017; 30:19-23. [DOI: 10.1016/j.sleep.2016.03.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/02/2016] [Accepted: 03/01/2016] [Indexed: 10/22/2022]
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Coppola G, Di Renzo A, Tinelli E, Lepre C, Di Lorenzo C, Di Lorenzo G, Scapeccia M, Parisi V, Serrao M, Colonnese C, Schoenen J, Pierelli F. Thalamo-cortical network activity between migraine attacks: Insights from MRI-based microstructural and functional resting-state network correlation analysis. J Headache Pain 2016; 17:100. [PMID: 27778244 PMCID: PMC5078119 DOI: 10.1186/s10194-016-0693-y] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 10/18/2016] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Resting state magnetic resonance imaging allows studying functionally interconnected brain networks. Here we were aimed to verify functional connectivity between brain networks at rest and its relationship with thalamic microstructure in migraine without aura (MO) patients between attacks. METHODS Eighteen patients with untreated MO underwent 3 T MRI scans and were compared to a group of 19 healthy volunteers (HV). We used MRI to collect resting state data among two selected resting state networks, identified using group independent component (IC) analysis. Fractional anisotropy (FA) and mean diffusivity (MD) values of bilateral thalami were retrieved from a previous diffusion tensor imaging study on the same subjects and correlated with resting state ICs Z-scores. RESULTS In comparison to HV, in MO we found significant reduced functional connectivity between the default mode network and the visuo-spatial system. Both HV and migraine patients selected ICs Z-scores correlated negatively with FA values of the thalamus bilaterally. CONCLUSIONS The present results are the first evidence supporting the hypothesis that an abnormal resting within networks connectivity associated with significant differences in baseline thalamic microstructure could contribute to interictal migraine pathophysiology.
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Affiliation(s)
- Gianluca Coppola
- Research Unit of Neurophysiology of Vision and Neurophthalmology, G.B. Bietti Foundation-IRCCS, Via Livenza 3, 00198, Rome, Italy.
| | - Antonio Di Renzo
- Research Unit of Neurophysiology of Vision and Neurophthalmology, G.B. Bietti Foundation-IRCCS, Via Livenza 3, 00198, Rome, Italy
| | - Emanuele Tinelli
- Department of Neurology and Psychiatry, Neuroradiology Section, "Sapienza" University of Rome, Rome, Italy
| | - Chiara Lepre
- Department of Medico-Surgical Sciences and Biotechnologies, Neurology Section, "Sapienza" University of Rome, Rome, Italy
| | | | - Giorgio Di Lorenzo
- Laboratory of Psychophysiology, Psychiatric Clinic, Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy
| | - Marco Scapeccia
- Department of Neurology and Psychiatry, Neuroradiology Section, "Sapienza" University of Rome, Rome, Italy
| | - Vincenzo Parisi
- Research Unit of Neurophysiology of Vision and Neurophthalmology, G.B. Bietti Foundation-IRCCS, Via Livenza 3, 00198, Rome, Italy
| | - Mariano Serrao
- Department of Medico-Surgical Sciences and Biotechnologies, "Sapienza" University of Rome Polo Pontino, Latina, Italy
| | - Claudio Colonnese
- Department of Neurology and Psychiatry, Neuroradiology Section, "Sapienza" University of Rome, Rome, Italy
- IRCCS Neuromed, Pozzilli, (IS), Italy
| | - Jean Schoenen
- Headache Research Unit, Department of Neurology-CHR Citadelle, University of Liège, Liège, Belgium
| | - Francesco Pierelli
- Department of Medico-Surgical Sciences and Biotechnologies, "Sapienza" University of Rome Polo Pontino, Latina, Italy
- IRCCS Neuromed, Pozzilli, (IS), Italy
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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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Kumru H, Albu S, Vidal J, Barrio M, Santamaria J. Dopaminergic treatment of restless legs syndrome in spinal cord injury patients with neuropathic pain. Spinal Cord Ser Cases 2016; 2:16022. [PMID: 28053765 DOI: 10.1038/scsandc.2016.22] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 06/27/2016] [Accepted: 07/01/2016] [Indexed: 11/09/2022] Open
Abstract
Recent studies report high incidence of restless legs syndrome (RLS) in patients with spinal cord injury (SCI), who may also present pain and sensory disturbances. In the present manuscript, we examine and discuss diagnostic and treatment challenges of comorbid RLS and neuropathic pain (NP) in SCI. We evaluated seven men with a mean age of 55.6 (s.d.=14.0) years, with chronic complete or incomplete SCI at the thoracic or lumbar level, for complaints of sensory disturbances in the legs, which initially were attributed to drug-resistant NP. Because overlapped RLS was suspected, clinical evaluation of NP and RLS, serum ferritin and iron level assessment, and video polysomnographic (VPSG) studies were conducted. Pramipexole (0.18 mg q.d.-1) was added to treat RLS, and a follow-up was performed at 2 months. We found that in six subjects the RLS was comorbid with NP and in one subject the symptoms of RLS were misdiagnosed as NP. VPSG revealed periodic limb movements (PLMs) in all patients, including PLMs of the legs, arms or both. Serum ferritin was <50 ng ml-1 in two patients. RLS improved significantly after 2 months with pramipexole. On the basis of current findings, we recommend physicians to be aware of the comorbidity between RLS and NP secondary to SCI to include suitable diagnostic procedures and effective treatments.
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Affiliation(s)
- Hatice Kumru
- Institut Guttmann, Institut Universitari de Neurorehabilitació adscrit a la UAB, Barcelona, Spain; Universidad Autonoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Spain; Fundació Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Barcelona, Spain
| | - Sergiu Albu
- Department of Psychology, Texas A&M University , College Station, TX, USA
| | - Joan Vidal
- Institut Guttmann, Institut Universitari de Neurorehabilitació adscrit a la UAB, Barcelona, Spain; Universidad Autonoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Spain; Fundació Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Barcelona, Spain
| | - Manuela Barrio
- Institut Guttmann, Institut Universitari de Neurorehabilitació adscrit a la UAB, Barcelona, Spain; Universidad Autonoma de Barcelona, Bellaterra (Cerdanyola del Vallès), Spain; Fundació Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol, Barcelona, Spain
| | - Joan Santamaria
- Servei de Neurologia, Hospital Clinic de Barcelona, Institut d'Investigació Biomèdica August Pi I Sunyer (IDIBAPS), University of Barcelona , Barcelona, Spain
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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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Mudumbi SV. RLS and PLMS: an avenue toward better understanding the natural history and spectrum of cerebrovascular disease? Sleep Med 2015; 16:1427-1428. [DOI: 10.1016/j.sleep.2015.07.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 07/23/2015] [Indexed: 12/13/2022]
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Dharmadhikari S, Ma R, Yeh CL, Stock AK, Snyder S, Zauber SE, Dydak U, Beste C. Striatal and thalamic GABA level concentrations play differential roles for the modulation of response selection processes by proprioceptive information. Neuroimage 2015; 120:36-42. [PMID: 26142275 DOI: 10.1016/j.neuroimage.2015.06.066] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 06/18/2015] [Accepted: 06/24/2015] [Indexed: 12/24/2022] Open
Abstract
The selection of appropriate responses is a complex endeavor requiring the integration of many different sources of information in fronto-striatal-thalamic circuits. An often neglected but relevant piece of information is provided by proprioceptive inputs about the current position of our limbs. This study examines the importance of striatal and thalamic GABA levels in these processes using GABA-edited magnetic resonance spectroscopy (GABA-MRS) and a Simon task featuring proprioception-induced interference in healthy subjects. As a possible model of deficits in the processing of proprioceptive information, we also included Parkinson's disease (PD) patients in this study. The results show that proprioceptive information about unusual postures complicates response selection processes in controls, but not in PD patients. The well-known deficits of PD patients in processing proprioceptive information can turn into a benefit when altered proprioceptive information would normally complicate response selection processes. Striatal and thalamic GABA levels play dissociable roles in the modulation of response selection processes by proprioceptive information: Striatal GABA levels seem to be important for the general speed of responding, most likely because striatal GABA promotes response selection. In contrast, the modulation of response conflict by proprioceptive information is closely related to thalamic GABA concentrations with higher concentration being related to a smaller response conflict effect. The most likely explanation for this finding is that the thalamus is involved in the integration of sensorimotor, attentional, and cognitive information for the purpose of response formation. Yet, this effect in the thalamus vanishes when controls and PD patients were analyzed separately.
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Affiliation(s)
- Shalmali Dharmadhikari
- School of Health Sciences, Purdue University, West Lafayette, IN, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ruoyun Ma
- School of Health Sciences, Purdue University, West Lafayette, IN, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Chien-Lin Yeh
- School of Health Sciences, Purdue University, West Lafayette, IN, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ann-Kathrin Stock
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine of the TU Dresden, Germany
| | - Sandy Snyder
- School of Health Sciences, Purdue University, West Lafayette, IN, USA
| | - S Elizabeth Zauber
- Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ulrike Dydak
- School of Health Sciences, Purdue University, West Lafayette, IN, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Christian Beste
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine of the TU Dresden, Germany
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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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Magalhães SC, Kaelin-Lang A, Sterr A, do Prado GF, Eckeli AL, Conforto AB. Transcranial magnetic stimulation for evaluation of motor cortical excitability in restless legs syndrome/Willis-Ekbom disease. Sleep Med 2015; 16:1265-73. [PMID: 26429756 DOI: 10.1016/j.sleep.2015.03.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 02/27/2015] [Accepted: 03/29/2015] [Indexed: 11/30/2022]
Abstract
There is no consensus about mechanisms underlying restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED). Cortical excitability may be abnormal in RLS. Transcranial magnetic stimulation (TMS) can provide insight about cortical excitability. We reviewed studies about measures of excitability to TMS in RLS. Original studies published between January 1999 and January 2015 were searched in PubMed, Scopus, and Web of Science databases. Inclusion criteria were as follows: original studies involving primary RLS in patients from both sexes and ages between 18 and 85 years; TMS protocols clearly described; and they were written in English, in peer-reviewed journals. Fifteen manuscripts were identified. TMS protocols were heterogeneous across studies. Resting motor threshold, active motor threshold, and amplitudes of motor-evoked potentials were typically reported to be normal in RLS. A reduction in short-interval intracortical inhibition (SICI) was the most consistent finding, whereas conflicting results were described in regard to short-interval intracortical facilitation and the contralateral silent period. Decreased SICI can be reversed by treatment with dopaminergic agonists. Plasticity in the motor cortex and sensorimotor integration may be disrupted. TMS may become a useful biomarker of responsiveness to drug treatment in RLS. The field can benefit from increases in homogeneity and sizes of samples, as well as from decrease in methodological variability across studies.
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Affiliation(s)
| | | | | | | | - Alan Luiz Eckeli
- Hospital das Clínicas da Faculdade de Medicina da USP, Ribeirão Preto, São Paulo, Brazil
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Wijemanne S, Jankovic J. Restless legs syndrome: clinical presentation diagnosis and treatment. Sleep Med 2015; 16:678-90. [PMID: 25979181 DOI: 10.1016/j.sleep.2015.03.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 02/28/2015] [Accepted: 03/02/2015] [Indexed: 12/27/2022]
Abstract
Restless legs syndrome (RLS) is a circadian disorder of sensory-motor integration that may be related to genetically determined dysregulation of iron transport across the blood-brain barrier. Dopamine agonists (DAs) have been considered the first-line therapy, but with the growing appreciation of problems associated with long-term treatment, particularly augmentation and impulse control disorder, alpha-2-delta drugs, such as gabapentin, are now considered the first line of treatment in patients with troublesome RLS. Opioids can be considered as an alternative therapy, particularly in patients with DA-related augmentation. In more severe cases, a combination therapy may be required. Intravenous iron therapy may be considered on those patients with refractory RLS.
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Affiliation(s)
- Subhashie Wijemanne
- Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Houston, Texas, USA
| | - Joseph Jankovic
- Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Houston, Texas, USA.
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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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