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Fernández V. The Use of Motor-Evoked Potentials in Clinical Trials in Multiple Sclerosis. J Clin Neurophysiol 2021; 38:166-170. [PMID: 33958566 DOI: 10.1097/wnp.0000000000000734] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SUMMARY Motor-evoked potentials (MEPs) can be used to assess the integrity of the descending corticospinal tract in the laboratory. Evoked potentials (EPs) have been widely used in the past for the diagnosis of multiple sclerosis (MS), but they are now becoming more useful in assessing the prognosis of the disease. Motor-evoked potentials have been included in EP scales that have demonstrated good correlations with clinical disability. Soon after the onset of MS, it is possible to detect an ongoing process of neurodegeneration and axonal loss. Axonal loss is probably responsible for the disability and disease progression that occurs in MS. Given the good correlations of EPs in detecting disease progression in MS, they have been used to monitor the effects of drugs used to treat the disease. Several clinical trials used MEPs as part of their EP evaluation, but MEPs have never been used as a measure of efficacy in clinical trials testing neuroprotective agents, although MEPs could be a very promising tool to measure neuroprotection and remyelination resulting from these drugs. To be used in multicenter clinical trials, MEP readings should be comparable between centers. Standardized multicenter EP assessment with central reading has been demonstrated to be feasible and reliable. Although MEP measurements have been correlated with clinical scores and other measures of neurodegeneration, further validation of MEP amplitude measurements is needed regarding their validity, reliability, and sensitivity before they can be routinely used in clinical drug trials in MS.
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Affiliation(s)
- Victoria Fernández
- Service of Clinical Neurophysiology, University Regional Hospital of Malaga, Malaga, Spain
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2
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Chaves AR, Wallack EM, Kelly LP, Pretty RW, Wiseman HD, Chen A, Moore CS, Stefanelli M, Ploughman M. Asymmetry of Brain Excitability: A New Biomarker that Predicts Objective and Subjective Symptoms in Multiple Sclerosis. Behav Brain Res 2019; 359:281-291. [DOI: 10.1016/j.bbr.2018.11.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 10/24/2018] [Accepted: 11/05/2018] [Indexed: 12/13/2022]
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3
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Ulivelli M, Monti L, Ballerini M, Bartalini S, Cerase A, Cecconi F, Pizzirusso G, Bezzini D, Rossi A, Rossi S. Prospective study of clinical, neurophysiological and urodynamic findings in multiple sclerosis patients undergoing percutaneous transluminal venous angioplasty. Clin Neurophysiol 2018; 130:138-144. [PMID: 30537671 DOI: 10.1016/j.clinph.2018.10.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 10/06/2018] [Accepted: 10/14/2018] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Verify whether Percutaneous Transluminal Angioplasty (PTA) may affect neural conduction properties in Multiple Sclerosis (MS) patients, thereby modifying patients' disability, with prospective neurophysiological, urodynamic, clinical and subjective well-being evaluations. METHODS In 55 out of 72 consecutively screened MS patients, the following procedures were carried out before (T0), at 2-6 months (T1) and at 6-15 months (T2) after a diagnostic phlebography, eventually followed by the PTA intervention if chronic cerebrospinal venous insufficiency (CCSVI) was diagnosed: clinical/objective evaluation (Expanded Disability Status Scale, EDSS), ratings of subjective well-being, evaluation of urodynamic functions and multimodal EPs (visual, acoustic, upper and lower limbs somatosensory and motor evoked potentials). RESULTS The number of dropouts was relatively high, and a complete set of neurophysiological and clinical data remained available for 37 patients (19 for urological investigations). The subjective well-being score significantly increased at T1 and returned close to basal values at T2, but their degree of objective disability did not change. Nevertheless, global EP-scores (indexing the impairment in conductivity of central pathways in multiple functional domains) significantly increased from T0 (7.9 ± 6.0) to T1 (9.2 ± 6.3) and from T0 to T2 (9.8 ± 6.3), but not from T1 and T2 (p > 0.05). Neurogenic urological lower tract dysfunctions slightly increased throughout the study. CONCLUSIONS The PTA intervention did not induce significant changes in disability in the present cohort of MS patients, in line with recent evidence of clinical inefficacy of this procedure. SIGNIFICANCE Absence of multimodal neurophysiological and functional testing changes in the first 15 months following PTA suggests that conduction properties of neural pathways are unaffected by PTA. Current findings suggest that the short-lived (2-6 months), post-PTA, beneficial effect on subjective well-being measures experienced by MS patients is likely related to a placebo effect.
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Affiliation(s)
- Monica Ulivelli
- Department of Medicine, Surgery and Neuroscience, Unit of Neurology and Clinical Neurophysiology, University of Siena, Italy.
| | - Lucia Monti
- Department of Medicine, Surgery and Neuroscience, NINT Section, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Michele Ballerini
- Department of Medicine, Surgery and Neuroscience, Unit of Neurology and Clinical Neurophysiology, University of Siena, Italy
| | - Sabina Bartalini
- Department of Medicine, Surgery and Neuroscience, Unit of Neurology and Clinical Neurophysiology, University of Siena, Italy
| | - Alfonso Cerase
- Department of Medicine, Surgery and Neuroscience, NINT Section, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Filippo Cecconi
- Urologia, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | | | | | - Alessandro Rossi
- Department of Medicine, Surgery and Neuroscience, Unit of Neurology and Clinical Neurophysiology, University of Siena, Italy; Department of Medicine, Surgery and Neuroscience, NINT Section, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Simone Rossi
- Department of Medicine, Surgery and Neuroscience, Unit of Neurology and Clinical Neurophysiology, University of Siena, Italy.
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Zipser CM, Premoli I, Belardinelli P, Castellanos N, Rivolta D, Heidegger T, Müller-Dahlhaus F, Ziemann U. Cortical Excitability and Interhemispheric Connectivity in Early Relapsing-Remitting Multiple Sclerosis Studied With TMS-EEG. Front Neurosci 2018; 12:393. [PMID: 29937712 PMCID: PMC6002497 DOI: 10.3389/fnins.2018.00393] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/22/2018] [Indexed: 12/26/2022] Open
Abstract
Evoked potentials (EPs) are well established in clinical practice for diagnosis and prognosis in multiple sclerosis (MS). However, their value is limited to the assessment of their respective functional systems. Here, we used transcranial magnetic stimulation (TMS) coupled with electroencephalography (TMS-EEG) to investigate cortical excitability and spatiotemporal dynamics of TMS-evoked neural activity in MS patients. Thirteen patients with early relapsing–remitting MS (RRMS) with a median Expanded Disability Status Scale (EDSS) of 1.0 (range 0–2.5) and 16 age- and gender-matched healthy controls received single-pulse TMS of left and right primary motor cortex (L-M1 and R-M1), respectively. Resting motor threshold for L-M1 and R-M1 was increased in MS patients. Latencies and amplitudes of N45, P70, N100, P180, and N280 TMS-evoked EEG potentials (TEPs) were not different between groups, except a significantly increased amplitude of the N280 TEP in the MS group, both for L-M1 and R-M1 stimulation. Interhemispheric signal propagation (ISP), estimated from the area under the curve of TEPs in the non-stimulated vs. stimulated M1, also did not differ between groups. In summary, findings show that ISP and TEPs were preserved in early-stage RRMS, except for an exaggerated N280 amplitude. Our findings indicate that TMS-EEG is feasible in testing excitability and connectivity in cortical neural networks in MS patients, complementary to conventional EPs. However, relevance and pathophysiological correlates of the enhanced N280 will need further study.
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Affiliation(s)
- Carl M Zipser
- Department of Neurology and Stroke, Hertie Institute for Clinical Brain Research, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Isabella Premoli
- Department of Neurology and Stroke, Hertie Institute for Clinical Brain Research, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Paolo Belardinelli
- Department of Neurology and Stroke, Hertie Institute for Clinical Brain Research, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Nazareth Castellanos
- Nirakara: Instituto de Investigación y Formación en Ciencias Cognitivas, Madrid, Spain
| | - Davide Rivolta
- Department of Education Science, Psychology and Communication Science, University of Bari Aldo Moro, Bari, Italy
| | - Tonio Heidegger
- Department of Neurology, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Florian Müller-Dahlhaus
- Department of Neurology and Stroke, Hertie Institute for Clinical Brain Research, Eberhard Karls University of Tübingen, Tübingen, Germany.,Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Mainz, Germany
| | - Ulf Ziemann
- Department of Neurology and Stroke, Hertie Institute for Clinical Brain Research, Eberhard Karls University of Tübingen, Tübingen, Germany
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Hardmeier M, Leocani L, Fuhr P. A new role for evoked potentials in MS? Repurposing evoked potentials as biomarkers for clinical trials in MS. Mult Scler 2017; 23:1309-1319. [PMID: 28480798 PMCID: PMC5564950 DOI: 10.1177/1352458517707265] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Evoked potentials (EP) characterize signal conduction in selected tracts of the central nervous system in a quantifiable way. Since alteration of signal conduction is the main mechanism of symptoms and signs in multiple sclerosis (MS), multimodal EP may serve as a representative measure of the functional impairment in MS. Moreover, EP have been shown to be predictive for disease course, and thus might help to select patient groups at high risk of progression for clinical trials. EP can detect deterioration, as well as improvement of impulse propagation, independently from the mechanism causing the change. Therefore, they are candidates for biomarkers with application in clinical phase-II trials. Applicability of EP in multicenter trials has been limited by different standards of registration and assessment.
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Affiliation(s)
- Martin Hardmeier
- Section of Clinical Neurophysiology, Department of Neurology, University Hospital of Basel, Basel, Switzerland
| | - Letizia Leocani
- Neurological Department and Institute of Experimental Neurology (INSPE) Scientific Institute, University Hospital San Raffaele, Milan, Italy
| | - Peter Fuhr
- Section of Clinical Neurophysiology, Department of Neurology, University Hospital of Basel, Basel, Switzerland
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Do evoked potentials contribute to the functional follow-up and clinical prognosis of multiple sclerosis? Acta Neurol Belg 2017; 117:53-59. [PMID: 27194163 DOI: 10.1007/s13760-016-0650-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 05/10/2016] [Indexed: 10/21/2022]
Abstract
The clinical variability and complexity of multiple sclerosis (MS) challenges the individual clinical course prognostication. This study aimed to find out whether multimodal evoked potentials (EP) correlate with the motor components of multiple sclerosis functional composite (MSFCm) and predict clinically relevant motor functional deterioration. One hundred MS patients were assessed at baseline (T 0) and about 7.5 years later (T 1), with visual, somatosensory and motor EP and rated on the Expanded Disability Status Scale (EDSS) and the MSFCm, including the 9 Hole Peg Test and the Timed 25 Foot Walk (T25FW). The Spearman correlation coefficient (r S) was used to evaluate the cross-sectional and longitudinal relationship between EP Z scores and clinical findings. The predictive value of baseline electrophysiological data for clinical worsening (EDSS, 9-HPT, T25FW, MSFCm) during follow-up was assessed by logistic regression analysis. Unlike longitudinal correlations, cross-sectional correlations between EP Z scores and clinical outcomes were all significant and ranged between 0.22 and 0.67 (p < 0.05). The global EP Z score was systematically predictive of EDSS and MSFCm worsening over time (all p < 0.05). EP latency was a better predictor than amplitude, although weaker than latency and amplitude aggregation in the global EP Z score. The study demonstrates that EP numerical scores can be used for motor function monitoring and outcome prediction in patients with MS.
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Giffroy X, Maes N, Albert A, Maquet P, Crielaard JM, Dive D. Multimodal evoked potentials for functional quantification and prognosis in multiple sclerosis. BMC Neurol 2016; 16:83. [PMID: 27245221 PMCID: PMC4888661 DOI: 10.1186/s12883-016-0608-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 05/23/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Functional biomarkers able to identify multiple sclerosis (MS) patients at high risk of fast disability progression are lacking. The aim of this study was to evaluate the ability of multimodal (upper and lower limbs motor, visual, lower limbs somatosensory) evoked potentials (EP) to monitor disease course and identify patients exposed to unfavourable evolution. METHODS One hundred MS patients were assessed with visual, somatosensory and motor EP and rated on the Expanded Disability Status Scale (EDSS) at baseline (T0) and about 6 years later (T1). The Spearman correlation (rS) was used to evaluate the relationship between conventional EP scores and clinical findings. Multiple (logistic) regression analysis estimated the predictive value of baseline electrophysiological data for three clinical outcomes: EDSS, annual EDSS progression, and the risk of EDSS worsening. RESULTS In contrast to longitudinal correlations, cross-sectional correlations between the different EP scores and EDSS were all significant (0.33 ≤ rS < 0.67, p < 0.001). Baseline global EP score and EDSS were highly significant predictors (p < 0.0001) of EDSS progression 6 years later. The baseline global EP score was found to be an independent predictor of the EDSS annual progression rate (p < 0.001), and of the risk of disability progression over time (p < 0.005). Based on a ROC curve determination, we defined a Global EP Score cut off point (17/30) to identify patients at high risk of disability progression illustrated by a positive predictive value of 70%. CONCLUSION This study provides a proof of the concept that electrophysiology could be added to MRI and used as another complementary prognostic tool in MS patients.
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Affiliation(s)
- Xavier Giffroy
- Department of Neurology, University Hospital of Liege, Rue Grandfosse 31-33, 4130, Esneux, Belgium.
- Department of Physical Medicine and Rehabilitation, University Hospital of Liege, B35, 4000, Liege, Belgium.
| | - Nathalie Maes
- Department of Biostatistics and Medico-Economic Information, University Hospital (CHU, ULg) of Liege, B35, 4000, Liège, Belgium
| | - Adelin Albert
- Department of Biostatistics and Medico-Economic Information, University Hospital (CHU, ULg) of Liege, B35, 4000, Liège, Belgium
| | - Pierre Maquet
- Department of Neurology, University Hospital of Liege, Rue Grandfosse 31-33, 4130, Esneux, Belgium
| | - Jean-Michel Crielaard
- Department of Physical Medicine and Rehabilitation, University Hospital of Liege, B35, 4000, Liege, Belgium
| | - Dominique Dive
- Department of Neurology, University Hospital of Liege, Rue Grandfosse 31-33, 4130, Esneux, Belgium
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Simpson M, Macdonell R. The use of transcranial magnetic stimulation in diagnosis, prognostication and treatment evaluation in multiple sclerosis. Mult Scler Relat Disord 2015; 4:430-436. [PMID: 26346791 DOI: 10.1016/j.msard.2015.06.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 06/10/2015] [Accepted: 06/22/2015] [Indexed: 11/26/2022]
Abstract
Despite advances in brain imaging which have revolutionised the diagnosis and monitoring of patients with Multiple Sclerosis (MS), current imaging techniques have limitations, including poor correlation with clinical disability and prognosis. There is growing evidence that electrophysiological techniques may provide complementary functional information which can aid in diagnosis, prognostication and perhaps even monitoring of treatment response in patients with MS. Transcranial magnetic stimulation (TMS) is an underutilised technique with potential to assist diagnosis, predict prognosis and provide an objective surrogate marker of clinical progress and treatment response. This review explores the existing body of evidence relating to the use of TMS in patients with MS, outlines the practical aspects and scope of TMS testing and reviews the current evidence relating to the use of TMS in diagnosis, disease classification, prognostication and response to symptomatic and disease-modifying therapies.
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Affiliation(s)
- Marion Simpson
- Department of Neurology, Austin Health and Faculty of Medicine, The University of Melbourne, Melbourne, Vic, Australia.
| | - Richard Macdonell
- Department of Neurology, Austin Health and Faculty of Medicine, The University of Melbourne, Melbourne, Vic, Australia
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Evoked potentials and disability in multiple sclerosis: A different perspective to a neglected method. Clin Neurol Neurosurg 2015; 133:11-7. [DOI: 10.1016/j.clineuro.2015.03.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 02/28/2015] [Accepted: 03/08/2015] [Indexed: 11/22/2022]
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10
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Abstract
The availability of new treatments able to modify the natural course of multiple sclerosis (MS) has generated interest in paraclinical measures to monitor disease evolution. Among these, neurophysiologic measures, mainly evoked potentials (EPs), are used in the functional assessment of central sensorimotor and cognitive networks affected by MS. EP abnormalities may reveal subclinical lesions, objectivate the involvement of sensory and motor pathways in the presence of vague disturbances, and provide indications of the demyelinating nature of the disease process. However, their diagnostic value is much lower than that of magnetic resonance imaging, and is more sensitive to brain and cervical spinal cord lesions. The application of EPs in assessing disease severity and monitoring the evolution of nervous damage is more promising, thanks to their good correlation with disability in cross-sectional and longitudinal studies, and potential use as paraclinical endpoints in clinical trials. Recent evidence indicates that EPs performed early in the disease may help to predict a worse future progression in the long term. If confirmed, these data suggest the possible usefulness of EPs in the early identification of patients who are more likely to develop future disability, thus requiring more frequent monitoring or being potential candidates for more aggressive disease-modifying treatments.
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Affiliation(s)
- Letizia Leocani
- Department of Neurology, Clinical Neurophysiology and Neurorehabilitation, University Hospital San Raffaele, Milan, Italy.
| | - Giancarlo Comi
- Department of Neurology, Clinical Neurophysiology and Neurorehabilitation, University Hospital San Raffaele, Milan, Italy
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Schlaeger R, Hardmeier M, Fuhr P. Superficial brain stimulation in multiple sclerosis. HANDBOOK OF CLINICAL NEUROLOGY 2013; 116:577-84. [PMID: 24112925 DOI: 10.1016/b978-0-444-53497-2.00046-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Central motor conduction time (CMCT) is the most frequently studied measure derived from transcranial magnetic stimulation (TMS) in multiple sclerosis (MS); it is abnormal in 57-93% of patients. Addition of the triple stimulation technique and combining motor with other evoked potentials (EPs) increases sensitivity. Cross-sectional correlations of TMS measures with clinical assessments of motor dysfunction or global disability are high. Longitudinally, CMCT is sensitive to both worsening and improvement of motor function, showing its potential to detect therapeutic responses. Moreover, combined multimodal EPs are valid quantitative predictors of the clinical course over periods ranging from 2 to 14 years. Measures of transcallosal connectivity (ipsilateral silent period and interhemispheric inhibition) are altered even in early MS, and yield complementary information on subclinical changes. Pathological brain plasticity in MS has been demonstrated by paired associative stimulation studies revealing a compensatory role of the ipsilateral motor and premotor areas. Central motor fatigue is associated with reduced motor EP amplitudes and increased cortical silent periods in normal controls, whereas patients with MS suffering from subjective fatigue show various abnormalities in cortical modulation of the motor system.
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Affiliation(s)
- Regina Schlaeger
- Department of Neurology, Hospitals of the University of Basel, Basel, Switzerland
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Abstract
Central motor conduction time (CMCT) is the time taken for neural impulses to travel through the central nervous system on their way to the target muscles. When the motor cortex is stimulated with transcranial magnetic stimulation (TMS), CMCT is calculated by subtracting the peripheral conduction time from the motor evoked potential latency elicited by motor cortical TMS. CMCT in infants and children reaches adult level at about age of 6 years for the lower limbs. The alterations of CMCT in various neurological conditions are reviewed in this chapter. Prolongation of CMCT occurs due to slowing of conduction through rapidly conducting corticospinal fibers, as seen in various disorders such as demyelinating diseases (multiple sclerosis, MS), amyotrophic lateral sclerosis, structural lesions in the corticospinal tract such as stroke and compressive myelopathy, and neurodegenerative disorders including multiple system atrophy and progressive supranuclear palsy. As CMCT is prolonged in certain clinical conditions, it is of diagnostic value in some neurological disorders such as myelopathy, amyotrophic lateral sclerosis, and MS when used together with other clinical and electrophysiological measures. It could also be used as a prognostic marker in some of neurological conditions, such as myelopathy and MS.
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Affiliation(s)
- Kaviraja Udupa
- Division of Neurology, Department of Medicine, University of Toronto and Division of Brain Imaging & Behaviour Systems - Neuroscience, Toronto Western Research Institute, Toronto, Canada
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Kale N, Agaoglu J, Onder G, Tanik O. Correlation between disability and transcranial magnetic stimulation abnormalities in patients with multiple sclerosis. J Clin Neurosci 2009; 16:1439-42. [DOI: 10.1016/j.jocn.2009.03.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Revised: 03/11/2009] [Accepted: 03/30/2009] [Indexed: 01/23/2023]
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Rico A, Audoin B, Franques J, Eusebio A, Reuter F, Malikova I, Ali Cherif A, Pouget J, Pelletier J, Attarian S. Motor evoked potentials in clinically isolated syndrome suggestive of multiple sclerosis. Mult Scler 2009; 15:355-62. [DOI: 10.1177/1352458508099612] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The aim of the present study was to determine the sensitivity and the profile of motor evoked potentials (MEP) in patients with clinically isolated syndrome (CIS) suggestive of multiple sclerosis (MS). We measured the central motor conduction time (CMCT), amplitude ratio (AR), and surface ratio (SR) in tibialis anterior and first dorsal interosseous muscles in 22 patients with CIS. In 12 patients, the triple stimulation technique (TST) was also performed. AR was abnormal in 50% of patients, CMCT in 18% of patients, and TST in 25% of patients. AR had the highest sub-clinical sensitivity and the best positive predictive value. In the absence of clinical pyramidal signs, an early AR decrease seems to result from demyelination inducing excessive temporal dispersion of the MEP, while in territories with clinical pyramidal signs, it seems to result from conduction failure, which suggests that clinical pyramidal signs may be attributable to conduction failure. This study demonstrates that MEP, especially the AR, is sensitive to motor pathway dysfunction right from the early stages of MS.
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Affiliation(s)
- A Rico
- Centre de Résonance Magnétique Biologique et Médicale UMR CNRS 6612, Faculté de Médecine, Université de la Méditerranée, Marseille, France; Pôle de Neurosciences Cliniques, Service de Neurologie, Faculté de Médecine de Marseille, Université de la Méditerranée, Hôpital de la Timone, Marseille, France
| | - B Audoin
- Centre de Résonance Magnétique Biologique et Médicale UMR CNRS 6612, Faculté de Médecine, Université de la Méditerranée, Marseille, France; Pôle de Neurosciences Cliniques, Service de Neurologie, Faculté de Médecine de Marseille, Université de la Méditerranée, Hôpital de la Timone, Marseille, France
| | - J Franques
- Pôle de Neurosciences Cliniques, Service de Neurologie et des pathologies neuromusculaires, Faculté de Médecine de Marseille, Université de la Méditerranée, Hôpital de la Timone, Marseille, France
| | - A Eusebio
- Pôle de Neurosciences Cliniques, Service de Neurologie et des pathologies neuromusculaires, Faculté de Médecine de Marseille, Université de la Méditerranée, Hôpital de la Timone, Marseille, France
| | - F Reuter
- Centre de Résonance Magnétique Biologique et Médicale UMR CNRS 6612, Faculté de Médecine, Université de la Méditerranée, Marseille, France; Pôle de Neurosciences Cliniques, Service de Neurologie, Faculté de Médecine de Marseille, Université de la Méditerranée, Hôpital de la Timone, Marseille, France
| | - I Malikova
- Centre de Résonance Magnétique Biologique et Médicale UMR CNRS 6612, Faculté de Médecine, Université de la Méditerranée, Marseille, France; Pôle de Neurosciences Cliniques, Service de Neurologie, Faculté de Médecine de Marseille, Université de la Méditerranée, Hôpital de la Timone, Marseille, France
| | - A Ali Cherif
- Pôle de Neurosciences Cliniques, Service de Neurologie, Faculté de Médecine de Marseille, Université de la Méditerranée, Hôpital de la Timone, Marseille, France
| | - J Pouget
- Pôle de Neurosciences Cliniques, Service de Neurologie et des pathologies neuromusculaires, Faculté de Médecine de Marseille, Université de la Méditerranée, Hôpital de la Timone, Marseille, France
| | - J Pelletier
- Centre de Résonance Magnétique Biologique et Médicale UMR CNRS 6612, Faculté de Médecine, Université de la Méditerranée, Marseille, France; Pôle de Neurosciences Cliniques, Service de Neurologie, Faculté de Médecine de Marseille, Université de la Méditerranée, Hôpital de la Timone, Marseille, France
| | - S Attarian
- Pôle de Neurosciences Cliniques, Service de Neurologie et des pathologies neuromusculaires, Faculté de Médecine de Marseille, Université de la Méditerranée, Hôpital de la Timone, Marseille, France
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Chen R, Cros D, Curra A, Di Lazzaro V, Lefaucheur JP, Magistris MR, Mills K, Rösler KM, Triggs WJ, Ugawa Y, Ziemann U. The clinical diagnostic utility of transcranial magnetic stimulation: Report of an IFCN committee. Clin Neurophysiol 2008; 119:504-532. [DOI: 10.1016/j.clinph.2007.10.014] [Citation(s) in RCA: 348] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 10/12/2007] [Accepted: 10/18/2007] [Indexed: 12/11/2022]
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16
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Audoin B, Guye M, Reuter F, Au Duong MV, Confort-Gouny S, Malikova I, Soulier E, Viout P, Chérif AA, Cozzone PJ, Pelletier J, Ranjeva JP. Structure of WM bundles constituting the working memory system in early multiple sclerosis: a quantitative DTI tractography study. Neuroimage 2007; 36:1324-30. [PMID: 17513134 DOI: 10.1016/j.neuroimage.2007.04.038] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Revised: 04/12/2007] [Accepted: 04/15/2007] [Indexed: 11/17/2022] Open
Abstract
Working memory impairment is frequently observed in patients with early multiple sclerosis (MS). MRI and functional MRI studies have shown that working memory impairment is mostly due to diffuse white matter (WM) damage affecting the connectivity between distant cortical areas. However, working memory deficits in early MS patients can be either completely or partly masked by compensatory functional plasticity. It seems likely that concomitantly with the WM bundle injury resulting from pathological processes, the functional plasticity present in early MS patients may be accompanied by reactive structural WM plasticity. This structural plasticity may effectively compensate for connectivity disturbances and/or contribute to functional brain reorganization. The diffusion characteristics of WM bundles involved in working memory were assessed here by performing quantitative diffusion tensor imaging (DTI) tractography on 24 patients with early relapsing-remitting MS and 15 healthy control subjects. The DTI tractography findings showed that WM connections constituting the executive system of working memory were structurally impaired (the fractional anisotropy was lower than normal and the mean diffusivity, higher than normal). A significantly larger number of connections between the left and right thalami was concurrently observed in the MS patients than in the control subjects, which suggests that the WM is endowed with reactive structural plasticity.
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Affiliation(s)
- Bertrand Audoin
- Centre de Résonance Magnétique Biologique et Médicale, UMR CNRS 6612, Faculté de Médecine, Université de la Méditerranée, 27 boulevard Jean Moulin, 13385 Marseille cedex 05, France
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