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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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2
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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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3
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Nardone R, Sebastianelli L, Versace V, Brigo F, Golaszewski S, Pucks-Faes E, Saltuari L, Trinka E. Contribution of transcranial magnetic stimulation in restless legs syndrome: pathophysiological insights and therapeutical approaches. Sleep Med 2020; 71:124-134. [PMID: 32088150 DOI: 10.1016/j.sleep.2019.12.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 12/10/2019] [Accepted: 12/11/2019] [Indexed: 01/06/2023]
Abstract
Transcranial magnetic stimulation (TMS) may offer a reliable means to characterize significant pathophysiologic and neurochemical aspects of restless legs syndrome (RLS). Namely, TMS has revealed specific patterns of changes in cortical excitability and plasticity, in particular dysfunctional inhibitory mechanisms and sensorimotor integration, which are thought to be part of the pathophysiological mechanisms of RLS rather than reflect a non-specific consequence of sleep architecture alteration. If delivered repetitively, TMS is able to transiently modulate the neural activity of the stimulated and connected areas. Some studies have begun to therapeutically use repetitive TMS (rTMS) to improve sensory and motor disturbances in RLS. High-frequency rTMS applied over the primary motor cortex or the supplementary motor cortex, as well as low-frequency rTMS over the primary somatosensory cortex, seem to have transient beneficial effects. However, further studies with larger patient samples, repeated sessions, an optimized rTMS setup, and clinical follow-up are needed in order to corroborate preliminary results. Thus, we performed a systematic search of all the studies that have used TMS and rTMS techniques in patients with RLS.
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Affiliation(s)
- Raffaele Nardone
- Department of Neurology, Franz Tappeiner Hospital, Merano, 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, Vipiteno, Italy; Research Unit for Neurorehabilitation South Tyrol, Bolzano, Italy
| | - Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno, Vipiteno, Italy; Research Unit for Neurorehabilitation South Tyrol, Bolzano, Italy
| | - Francesco Brigo
- Department of Neurology, Franz Tappeiner Hospital, Merano, Italy; Department of Neuroscience, Biomedicine and Movement Science, University of Verona, Italy
| | - Stefan Golaszewski
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Karl Landsteiner Institut für Neurorehabilitation und Raumfahrtneurologie, Salzburg, Austria
| | | | - Leopold Saltuari
- Department of Neurorehabilitation, Hospital of Vipiteno, Vipiteno, Italy; Research Unit 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 Neurosciences Salzburg, Salzburg, Austria; University for Medical Informatics and Health Technology, UMIT, Hall in Tirol, Austria
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4
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Jiménez-Jiménez FJ, Alonso-Navarro H, García-Martín E, Agúndez JA. Neurochemical features of idiopathic restless legs syndrome. Sleep Med Rev 2019; 45:70-87. [DOI: 10.1016/j.smrv.2019.03.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 03/08/2019] [Accepted: 03/15/2019] [Indexed: 11/26/2022]
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5
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Connecting clinical aspects to corticomotor excitability in restless legs syndrome: a TMS study. Sleep Med 2018; 49:105-112. [DOI: 10.1016/j.sleep.2018.05.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/27/2018] [Accepted: 05/04/2018] [Indexed: 01/07/2023]
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de Paiva JPQ, Magalhães SC, do Prado GF, Eckeli AL, Kaelin-Lang A, Conforto AB. The duration of the cortical silent period is not abnormal in Restless Legs Syndrome/Willis-Ekbom Disease. J Neurol Sci 2017; 375:35-42. [PMID: 28320166 DOI: 10.1016/j.jns.2016.12.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 11/28/2016] [Accepted: 12/28/2016] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To compare the duration of the cortical silent period (CSP) measured in a hand muscle in subjects with primary Restless Legs Syndrome (RLS/WED) and controls, using four different methods of analysis. METHODS The CSP to transcranial magnetic stimulation of the dominant motor cortex was assessed in the abductor digiti minimi of 33 subjects with RLS/WED and 24 controls. CSP duration was measured by an automated and three visually-guided methods. RESULTS There were significant differences between absolute values of CSP duration according to the method of analysis. However, irrespectively of the method used for CSP assessment, no differences were found between measurements performed in subjects with RLS/WED and subjects from the control group. CONCLUSIONS Absolute values of CSP durations analyzed by different methods should not be directly compared, because significantly different results can be obtained from the same data set. SIGNIFICANCE The CSP assessed from a hand muscle is unlikely to be a biomarker of primary RLS/WED. Our results highlight the importance of standardizing the definition of CSP onset and offset, as well as of describing in detail the methodology chosen to record and measure CSP duration, in order to enable comparisons between studies.
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Affiliation(s)
- Joselisa Péres Queiroz de Paiva
- Hospital Israelita Albert Einstein, Edifício Josef Féher (Bloco A), 2° subsolo, Av. Albert Einstein, 627/701, São Paulo, SP, Brazil CEP: 05652-900.
| | - Samir Câmara Magalhães
- Hospital Israelita Albert Einstein, Edifício Josef Féher (Bloco A), 2° subsolo, Av. Albert Einstein, 627/701, São Paulo, SP, Brazil CEP: 05652-900.
| | - Gilmar Fernandes do Prado
- Universidade Federal de São Paulo, Departamento de Neurologia e Neurocirurgia, Rua Claúdio Rossi, 394, São Paulo, SP, Brazil CEP: 01547-000.
| | - Alan Luiz Eckeli
- Hospital das Clínicas da Faculdade de Medicina, Departamento de Neurociências e Ciências do Comportamento, Divisão de Neurologia, Hospital das Clinicas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil CEP: 14.048-900.
| | - Alain Kaelin-Lang
- Neurocenter of Southern Switzerland, LBN - Laboratory for Biomedical Neurosciences, 6900 Lugano, Switzerland.
| | - Adriana Bastos Conforto
- Hospital Israelita Albert Einstein, Edifício Josef Féher (Bloco A), 2° subsolo, Av. Albert Einstein, 627/701, São Paulo, SP, Brazil CEP: 05652-900; Hospital das Clínicas da Faculdade de Medicina, Departamento de Neurologia e Núcleo de Apoio à Pesquisa em Neurociência Aplicada (NAPNA), Universidade de São Paulo, São Paulo, SP, Brazil CEP: 05403-010.
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7
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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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8
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Bocquillon P, Charley-Monaca C, Houdayer E, Marques A, Kwiatkowski A, Derambure P, Devanne H. Reduced afferent-induced facilitation of primary motor cortex excitability in restless legs syndrome. Sleep Med 2017; 30:31-35. [DOI: 10.1016/j.sleep.2016.03.007] [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: 12/02/2015] [Revised: 02/03/2016] [Accepted: 03/13/2016] [Indexed: 01/18/2023]
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9
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Howell M. Darwin's Predisposition and the Restlessness that Drives Sleepwalking. Sleep 2015; 38:1667-8. [PMID: 26446122 DOI: 10.5665/sleep.5134] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 10/01/2015] [Indexed: 11/03/2022] Open
Affiliation(s)
- Michael Howell
- Department of Neurology, University of Minnesota, Minneapolis, MN; University of Minnesota Medical Center, Fairview, Minneapolis, MN; Sleep Medicine Clinic, University of Minnesota Medical Center Fairview, Minneapolis, MN, Minnesota Regional Sleep Disorders Center, Minneapolis, MN; Minnesota Regional Sleep Disorders Center, Hennepin County Medical Center, Minneapolis, MN
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10
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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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Lanza G, Cantone M, Lanuzza B, Pennisi M, Bella R, Pennisi G, Ferri R. Distinctive patterns of cortical excitability to transcranial magnetic stimulation in obstructive sleep apnea syndrome, restless legs syndrome, insomnia, and sleep deprivation. Sleep Med Rev 2015; 19:39-50. [PMID: 24849846 DOI: 10.1016/j.smrv.2014.04.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 01/25/2014] [Accepted: 04/03/2014] [Indexed: 02/07/2023]
Abstract
Altered responses to transcranial magnetic stimulation (TMS) in obstructive sleep apnea syndrome (OSAS), restless legs syndrome (RLS), insomnia, and sleep-deprived healthy subjects have been reported. We have reviewed the relevant literature in order to identify eventual distinctive electrocortical profiles based on single and paired-pulse TMS, sensorimotor modulation, plasticity-related and repetitive TMS measures. Although obtained from heterogeneous studies, the detected changes might be the result of the different pathophysiological substrates underlying OSAS, RLS, insomnia and sleep deprivation rather than reflect the general effect of non-specific sleep loss and instability. OSAS tends to exhibit an increased motor cortex inhibition, which is reduced in RLS; intracortical excitability seems to be in favor of an "activating" profile in chronic insomnia and in sleep-deprived healthy individuals. Abnormal plasticity-related TMS phenomena have been demonstrated in OSAS and RLS. This review provides a perspective of TMS techniques by further understanding the role of neurotransmission pathways and plastic remodeling of neuronal networks involved in common sleep disorders. TMS might be considered a valuable tool in the assessment of sleep disorders, the evaluation of the effect of therapy and the design of non-pharmacological approaches.
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Affiliation(s)
- Giuseppe Lanza
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73, 94018 Troina, EN, Italy.
| | - Mariagiovanna Cantone
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73, 94018 Troina, EN, Italy
| | - Bartolo Lanuzza
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73, 94018 Troina, EN, Italy
| | - Manuela Pennisi
- Department of Chemistry, University of Catania, Viale Andrea Doria, 6, 95125 Catania, Italy
| | - Rita Bella
- Department "G.F. Ingrassia", Section of Neurosciences, University of Catania, Via Santa Sofia, 78, 95123 Catania, Italy
| | - Giovanni Pennisi
- Department "G.F. Ingrassia", Section of Neurosciences, University of Catania, Via Santa Sofia, 78, 95123 Catania, Italy
| | - Raffaele Ferri
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73, 94018 Troina, EN, Italy
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12
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Lanza G, Lanuzza B, Aricò D, Cantone M, Cosentino FII, Pennisi M, Bella R, Pennisi G, Ferri R. Direct comparison of cortical excitability to transcranial magnetic stimulation in obstructive sleep apnea syndrome and restless legs syndrome. Sleep Med 2015; 16:138-42. [PMID: 25534710 DOI: 10.1016/j.sleep.2014.08.016] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 08/10/2014] [Accepted: 08/26/2014] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Changes to transcranial magnetic stimulation (TMS) have been reported in obstructive sleep apnea syndrome (OSAS) and restless legs syndrome (RLS), although no direct comparison study is available. The aim of this new investigation is to assess and compare cortical excitability of OSAS and RLS patients using the same methodology and under the same experimental conditions. METHODS Fourteen patients with OSAS and 12 with RLS were compared to 14 age-matched controls. All patients were untreated and had a severe degree of disease. Resting motor threshold (rMT), cortical silent period (CSP) and motor evoked potentials MEPs, as well as intracortical inhibition (ICI) and facilitation at interstimulus interval (ISI) of 3 and 10 ms, respectively, were explored from the right first dorsal interosseous muscle, during wakefulness. RESULTS rMT was higher in OSAS than in RLS and controls. CSP was shorter in RLS only when compared to apneic patients, whereas it was similar between OSAS and controls. OSAS subjects exhibited slightly prolonged central motor conductivity, whereas MEP amplitude was smaller in both patient groups. The ICI ratio at ISI of 3 ms was decreased in RLS patients only. CONCLUSIONS Distinct changes of responses at TMS were found, probably connected with the different neurophysiological substrates underlying OSAS and RLS and could not be interpreted as a mere reflection of the effects of sleep architecture alteration. TMS can be considered an additional tool for the understanding of clinical and pathophysiological aspects of sleep disorders, and possibly for the evaluation of the effect of therapy.
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Affiliation(s)
- Giuseppe Lanza
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73 - 94018 Troina (EN), Italy.
| | - Bartolo Lanuzza
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73 - 94018 Troina (EN), Italy
| | - Debora Aricò
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73 - 94018 Troina (EN), Italy
| | - Mariagiovanna Cantone
- Department of Chemistry, University of Catania, Viale Andrea Doria, 6 - 95125 Catania, Italy
| | - Filomena Irene Ilaria Cosentino
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73 - 94018 Troina (EN), Italy
| | - Manuela Pennisi
- Department of Chemistry, University of Catania, Viale Andrea Doria, 6 - 95125 Catania, Italy
| | - Rita Bella
- Department "G.F. Ingrassia", Section of Neurosciences, University of Catania. Via Santa Sofia, 78 - 95123 Catania, Italy
| | - Giovanni Pennisi
- Department "G.F. Ingrassia", Section of Neurosciences, University of Catania. Via Santa Sofia, 78 - 95123 Catania, Italy
| | - Raffaele Ferri
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero, 73 - 94018 Troina (EN), Italy
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13
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Abad VC, Guilleminault C. Pharmacological treatment of sleep disorders and its relationship with neuroplasticity. Curr Top Behav Neurosci 2015; 25:503-53. [PMID: 25585962 DOI: 10.1007/7854_2014_365] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Sleep and wakefulness are regulated by complex brain circuits located in the brain stem, thalamus, subthalamus, hypothalamus, basal forebrain, and cerebral cortex. Wakefulness and NREM and REM sleep are modulated by the interactions between neurotransmitters that promote arousal and neurotransmitters that promote sleep. Various lines of evidence suggest that sleep disorders may negatively affect neuronal plasticity and cognitive function. Pharmacological treatments may alleviate these effects but may also have adverse side effects by themselves. This chapter discusses the relationship between sleep disorders, pharmacological treatments, and brain plasticity, including the treatment of insomnia, hypersomnias such as narcolepsy, restless legs syndrome (RLS), obstructive sleep apnea (OSA), and parasomnias.
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Affiliation(s)
- Vivien C Abad
- Psychiatry and Behavioral Science-Division of Sleep Medicine, Stanford University School of Medicine, Palo Alto, CA, USA
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14
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Nardone R, Höller Y, Brigo F, Tezzon F, Golaszewski S, Trinka E. Transcranial magnetic stimulation and sleep disorders: pathophysiologic insights. Sleep Med 2013; 14:1047-58. [PMID: 24051115 DOI: 10.1016/j.sleep.2013.04.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 04/28/2013] [Accepted: 04/30/2013] [Indexed: 01/15/2023]
Abstract
The neural mechanisms underlying the development of the most common intrinsic sleep disorders are not completely known. Therefore, there is a great need for noninvasive tools which can be used to better understand the pathophysiology of these diseases. Transcranial magnetic stimulation (TMS) offers a method to noninvasively investigate the functional integrity of the motor cortex and its corticospinal projections in neurologic and psychiatric diseases. To date, TMS studies have revealed cortical and corticospinal dysfunction in several sleep disorders, with cortical hyperexcitability being a characteristic feature in some disorders (i.e., the restless legs syndrome) and cortical hypoexcitability being a well-established finding in others (i.e., obstructive sleep apnea syndrome narcolepsy). Several research groups also have applied TMS to evaluate the effects of pharmacologic agents, such as dopaminergic agent or wake-promoting substances. Our review will focus on the mechanisms underlying the generation of abnormal TMS measures in the different types of sleep disorders, the contribution of TMS in enhancing the understanding of their pathophysiology, and the potential diagnostic utility of TMS techniques. We also briefly discussed the possible future implications for improving therapeutic approaches.
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Affiliation(s)
- Raffaele Nardone
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Department of Neurology, Franz Tappeiner Hospital, Merano, Italy.
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16
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Recurrent CSPs after Transcranial Magnetic Stimulation of Motor Cortex in Restless Legs Syndrome. Neurol Res Int 2012; 2012:628949. [PMID: 23213521 PMCID: PMC3507135 DOI: 10.1155/2012/628949] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 10/20/2012] [Accepted: 10/20/2012] [Indexed: 11/21/2022] Open
Abstract
Aims. The aim of this study was to investigate the motor control and central silent period (CSP) in restless legs syndrome (RLS). Methods. Transcranial magnetic stimulation was focused on the dominant and nondominant hemispheric areas of motor cortex in six subjects with RLS and six controls. The responses were recorded on the contralateral abductor digiti minimi (ADM) and tibialis anterior (TA) muscles with intramuscular needle electrodes. Results. No significant differences were found in the motor conduction or central motor conduction time, in the latency, or in the duration of the CSPs between or within the groups, but multiple CSPs were observed in both groups. The number of the CSPs was significantly higher in both ADMs and in the dominant TA (P ≤ 0.01) in the RLS group compared to the controls. Conclusion. Descending motor pathways functioned correctly in both groups. The occurrence of the recurrent CSPs predominantly in the RLS group could be a sign of a change of function in the inhibitory control system. Further research is needed to clarify the role of the intramuscular recording technique and especially the role of the subcortical generators in the feedback regulation of the central nervous system in RLS.
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Gündüz A, Adatepe NU, Kiziltan ME, Karadeniz D, Uysal O. Cırcadian changes in cortical excitability in restless legs syndrome. J Neurol Sci 2012; 316:122-5. [PMID: 22305328 DOI: 10.1016/j.jns.2012.01.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Revised: 01/06/2012] [Accepted: 01/11/2012] [Indexed: 01/18/2023]
Abstract
Various investigations have revealed a widespread and somewhat controversial pattern of cerebral, cerebellar and brainstem involvement in the pathophysiology of restless legs syndrome (RLS). However, several studies which investigated functional or structural aspects indicated cortical involvement in RLS. In this study, we aimed to analyze circadian changes of cortical excitability in idiopathic RLS patients by means of transcranial magnetic stimulation (TMS). Eleven idiopathic RLS patients and eight healthy age and sex matched subjects were investigated using single-pulse TMS and motor nerve conduction studies during early afternoon when there were no symptoms and late at night (22:00-23:00) when the symptoms reappeared. Central motor conduction time, latencies and amplitudes of scalp and cervical motor evoked potentials, resting and active motor thresholds, and cortical silent period were measured. Measured parameters were similar between RLS patients and healthy subjects during the daytime. At night, cortical silent periods tended to shorten, and motor thresholds tended to decrease in the RLS group, whereas in controls they tended to increase. At night, active motor-threshold measurements were significantly lower in the RLS group (28.5 ± 6.2% vs 40.4 ± 8.4%, p=0.006). Therefore, we propose that in patients with RLS, conduction along the motor corticospinal axons is normal, with the possible loss of subcortical inhibition at nighttime.
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Affiliation(s)
- Ayşegül Gündüz
- Istanbul University, Cerrahpasa School of Medicine, Department of Neurology, Istanbul, Turkey.
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Effect of pramipexole on cutaneous-silent-period parameters in patients with restless legs syndrome. Clin Neurophysiol 2012; 123:154-9. [DOI: 10.1016/j.clinph.2011.05.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2011] [Revised: 05/06/2011] [Accepted: 05/29/2011] [Indexed: 11/23/2022]
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Rizzo V, Aricò I, Liotta G, Ricciardi L, Mastroeni C, Morgante F, Allegra R, Condurso R, Girlanda P, Silvestri R, Quartarone A. Impairment of sensory-motor integration in patients affected by RLS. J Neurol 2010; 257:1979-85. [DOI: 10.1007/s00415-010-5644-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 05/31/2010] [Accepted: 06/28/2010] [Indexed: 11/28/2022]
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Giummarra MJ, Bradshaw JL. The phantom of the night: Restless legs syndrome in amputees. Med Hypotheses 2010; 74:968-72. [DOI: 10.1016/j.mehy.2009.12.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Accepted: 12/09/2009] [Indexed: 02/01/2023]
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Scalise A, Pittaro-Cadore I, Janes F, Marinig R, Gigli GL. Changes of cortical excitability after dopaminergic treatment in restless legs syndrome. Sleep Med 2010; 11:75-81. [PMID: 19595629 DOI: 10.1016/j.sleep.2009.05.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Revised: 04/27/2009] [Accepted: 05/01/2009] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Dopaminergic pathways are most likely involved in the pathophysiology of restless legs syndrome (RLS). In previous investigations, an alteration of cortical excitability was suggested to be related to a dopaminergic dysfunction in RLS. The purpose of our study was to compare practice-dependent plasticity in RLS patients before and after a month of dopaminergic treatment. METHODS Single-pulse transcranial magnetic stimulation (TMS) was used to define motor evoked potential (MEP) amplitude, motor threshold, and silent period (SP) as well. Subjects performed three exercise blocks (bimanual motor task). MEP amplitude, registered immediately after each exercise block and after a rest period, was compared to baseline. The time course of intra-cortical inhibition was tested using paired-pulse TMS at short inter-stimulus intervals. For the single-pulse TMS procedures, we enrolled 12 patients affected by primary RLS and 12 normal subjects. For the paired-pulse TMS procedures, only six patients underwent the examination. RLS patients underwent the examination in both pre- and post-dopaminergic treatment conditions. RESULTS In RLS patients MEP amplitude increased after the rest period only in the post-treatment condition, showing a delayed facilitation. After exercise, MEP amplitude increased, but not enough to be significant, showing a positive trend but not a clear-cut post-exercise facilitation. In the pre-treatment condition instead, MEP amplitude did not change either after rest period or after exercise. RLS patients showed a marked increase of the central motor inhibition, assessed by using paired-pulse TMS at short inter-stimulus intervals after pramipexole treatment. On the contrary, the duration of the SP did not change compared to the pre-treatment condition. CONCLUSIONS In RLS patients after dopaminergic treatment, the main finding was the changing of MEP amplitude after rest following a motor task. Since dopaminergic treatment can reverse delayed facilitation in RLS, we hypothesized that cortical plasticity related to dopaminergic systems may play a crucial role in RLS pathophysiology.
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Affiliation(s)
- Anna Scalise
- Department of Neurosciences, S. Maria della Misericordia University-Hospital, Udine, Italy.
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Scalise A. Patho-physiology of restless legs syndrome: A very tedious puzzle! Sleep Med 2009; 10:1073-4. [DOI: 10.1016/j.sleep.2009.02.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2009] [Accepted: 02/10/2009] [Indexed: 11/15/2022]
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Tyvaert L, Houdayer E, Devanne H, Bourriez JL, Derambure P, Monaca C. Cortical involvement in the sensory and motor symptoms of primary restless legs syndrome. Sleep Med 2009; 10:1090-6. [PMID: 19427261 DOI: 10.1016/j.sleep.2008.11.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Revised: 11/05/2008] [Accepted: 11/06/2008] [Indexed: 01/18/2023]
Abstract
BACKGROUND Restless legs syndrome (RLS) is characterized by closely interrelated motor and sensory disorders. Two types of involuntary movement can be observed: periodic leg movements during wakefulness (PLMW) and periodic leg movements during sleep (PLMS). Basal ganglia dysfunction in primary RLS has often been suggested. However, clinical observations raise the hypothesis of sensorimotor cortical involvement in RLS symptoms. Here, we explored cortical function via movement-related beta and mu rhythm reactivity. METHODS Twelve patients with idiopathic, primary RLS were investigated and compared with 10 healthy subjects. In the patient group, we analyzed event-related beta and mu (de)synchronization (ERD/S) for PLMS and PLMW during a suggested immobilization test (SIT). An ERD/S analysis was also performed in patients and controls during self-paced right ankle dorsal flexion at 8:30 PM (i.e., the symptomatic period for patients) and 8:30 AM (the asymptomatic period). RESULTS Before PLMS, there was no ERD. Intense ERS was recorded after PLMS. As with voluntary movement, cortical ERD was always observed before PLMW. After PLMW, ERS had a diffuse scalp distribution. Furthermore, the ERS and ERD amplitudes and durations for voluntary movement were greater during the symptomatic period than during the asymptomatic period and in comparison with healthy controls, who presented an evening decrease in these parameters. Patients and controls had similar ERD and ERS patterns in the morning. CONCLUSION On the basis of a rhythm reactivity study, we conclude that the symptoms of RLS are related to cortical sensorimotor dysfunction.
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Affiliation(s)
- L Tyvaert
- Clinical Neurophysiology Department, Roger Salengro Hospital, Lille University Medical Center, Lille, France
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Civardi C, Collini A, Monaco F, Cantello R. Applications of transcranial magnetic stimulation in sleep medicine. Sleep Med Rev 2009; 13:35-46. [DOI: 10.1016/j.smrv.2008.04.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Influence of cabergoline on motor excitability in patients with restless legs syndrome. J Clin Neurophysiol 2008; 24:456-60. [PMID: 18090527 DOI: 10.1097/wnp.0b013e31815a0038] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
To investigate whether the increased urge to move the legs in restless legs syndrome (RLS) corresponds to an electrophysiological phenomenon and whether motor excitability or behavior is influenced by the treatment with a dopamine agonist. We examined 10 patients who had RLS with transcranial magnetic stimulation (TMS) before and during treatment with the dopamine agonist cabergoline. Results were compared with data obtained from healthy subjects. Inhibitory mechanisms were explored by measurement of the cortical silent period (cSP). Recordings were obtained from the right anterior tibial muscle. Clinical severity of RLS was rated using the International Restless Legs Syndrome Study Group Rating Scale (IRLSSGRS). During therapy with cabergoline, all patients reported a significant improvement of RLS symptoms. Before medication, patients showed a significant shortening of cSP compared with healthy subjects. After 14 days of treatment with cabergoline, cSP normalized in RLS patients; 90 days after the start of daily cabergoline, cSP tended to shorten again, whereas RLS symptoms further improved. There was no correlation between cSP duration and IRLSSGRS results. There were no differences in patient and control motor thresholds. These thresholds remained unchanged during treatment with cabergoline. RLS patients have a disturbance of inhibitory neurons that can temporarily be reversed with a dopamine agonist. However, the cSP does not correlate with the clinical symptoms.
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Han JK, Oh K, Kim BJ, Koh SB, Kim JY, Park KW, Lee DH. Cutaneous silent period in patients with restless leg syndrome. Clin Neurophysiol 2007; 118:1705-10. [PMID: 17587642 DOI: 10.1016/j.clinph.2007.04.024] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2007] [Revised: 04/20/2007] [Accepted: 04/30/2007] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To investigate the pathophysiological relationship between RLS and small fiber neuropathy using the cutaneous silent period (CSP), which is a spinal reflex mediated by Adelta cutaneous afferents and is useful for the evaluation of small-diameter nerve function. METHODS The CSP was measured from the extensor digitorum brevis in 157 patients with RLS and 60 healthy controls. The CSP measurement was repeated in the RLS patients after dopamine agonist treatment for one month. The RLS rating scale for clinical severity was used to evaluate each patient before and after treatment. The measured CSP variables were compared between the patient group and the control group. In addition, the possible correlation between the CSP variables and the RLS rating scale score related to treatment was analyzed. RESULTS The mean CSP latencies did not differ between the RLS patients and the healthy controls; however, the mean CSP duration was significantly longer in the RLS patients than in the controls, and this prolonged CSP duration improved to the level of the control subjects after dopamine agonist treatment (p=0.003). The mean RLS rating scale score also significantly decreased after medication (p=0.000). However, the changes in the CSP variables did not correlate with the decrement in the RLS rating scale score. CONCLUSIONS Although our results do not support the role of Adelta fiber dysfunction in RLS, the observed change in CSP duration may be useful as a clinical measure of the improvement with dopamine agonist treatment in patients with RLS. SIGNIFICANCE Further study is needed to elucidate the exact mechanism involved in the prolonged CSP duration in response to treatment.
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Affiliation(s)
- Jin-Kyu Han
- Department of Neurology, Korea University Medical Center, Korea University College of Medicine, #126-1, Anam-Dong 5Ga, Seongbuk-Gu, Seoul 136-705, Republic of Korea
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Akpinar S, Aydin H, Kutukcu Y. In restless legs syndrome, during changes in vigilance, the forced EEG shifts from alpha activity to delta or high alpha may lead to the altered states of dopamine receptor function and the symptoms. Med Hypotheses 2007; 69:273-81. [PMID: 17320307 DOI: 10.1016/j.mehy.2006.12.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2006] [Accepted: 12/06/2006] [Indexed: 11/21/2022]
Abstract
RLS cases may carry a genetic vulnerability called EEG alpha activity gate dyscontrols which appear during changes in vigilance and generally during sleep. It is triggered by forced EEG shifts either from alpha activity to delta or high alpha. Expressions of alpha activity gate dyscontrols may have a gate effect that trigger a second vulnerability-dopamine receptor specific individual sensitivity (DRSIS) and this leads to a deficiency in dopamine transmissions at diencephalospinal dopamine system (DSDS). Due to altered gene expressions in states of dopamine receptor function, DRSIS EEGs and RLS symptoms may be interpreted as follows: A. Disinhibition state is alpha activity gate dyscontrols induced inhibition of DSDS inhibitory dopamine modulations. Dopaminergic disinhibitions inhibit inhibitory interneurons of sensory and motor nuclei neurons that are involved in RLS. These sleep sensitive inhibitory interneurons possibly have GABA-ergic functions in sleep. (I) DSDS thalamic neurons' disinhibitory effects in thalamus on GABA-ergic interneurons of: (a) Intralaminar nuclei non-discriminative sensation neurons at thalamocortical premotor network leading to symptom of "a sense of urgency to move" generally referenced to legs.(b) Reticular thalamic nucleus (RTN) neurons. At polysomnography,during NREM sleep, disinhibited RTN neurons show alpha activity gate dyscontrol 1. These are recurrent subtypes of CAP in alpha band (7-12 Hz) pointing a difficulty in shifting to subtypes of CAP in low delta bands (0.25-2.5 Hz) and sleep fragmentations.(II) Supraspinal disinhibitory projections from DSDS thalamic neurons on GABA-ergic interneurons of: (a) Sensory neurons at posterior horns of spinal cord leading to dysesthesias, generally referenced to legs.(b) Medullary-reticulospinal neurons and by way of independent spinal rhythm generators on motoneurons leading to periodic limb movements in sleep.B. Activation state is an increase in symptoms. Sensory intralaminar and motor pontin nuclei neurons are in fact excitatory but are disinhibited in RLS. Due to altered gene expression, these neurons begin to perceive 'disinhibition' as reduced inhibition. Their glutamate receptors may activate deficient dopamine transmissions on RTN leading to alpha activity gate dyscontrol 2. This implies a failure in preventing shifts to frequent subtypes of CAP in high alpha and low beta bands (12-13 Hz) resulting in an increase of sensorimotor symptoms and appearance of motor restlessness, behavioral arousals and insomnia. C. Inhibition state is spontaneous relief from sensorimotor symptoms. Short or long-term synaptic plasticities of dopamine receptors towards activations initiate negative feedbacks from inhibitory interneurons. They are supported by inhibitory dopamine modulations- alertness and some awareness generally with regular high alpha EEGs, supraspinal inhibitions and a reverse movement pattern of PLMS during standing up and continuing to walk.
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Affiliation(s)
- Sevket Akpinar
- Department of Neurology, Gülhane Military Medical Academy, Medical Faculty-Etlik, Ankara, Turkey.
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