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Dharmadasa T, Pavey N, Tu S, Menon P, Huynh W, Mahoney CJ, Timmins HC, Higashihara M, van den Bos M, Shibuya K, Kuwabara S, Grosskreutz J, Kiernan MC, Vucic S. Novel approaches to assessing upper motor neuron dysfunction in motor neuron disease/amyotrophic lateral sclerosis: IFCN handbook chapter. Clin Neurophysiol 2024; 163:68-89. [PMID: 38705104 DOI: 10.1016/j.clinph.2024.04.010] [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: 10/01/2023] [Revised: 02/08/2024] [Accepted: 04/14/2024] [Indexed: 05/07/2024]
Abstract
Identifying upper motor neuron (UMN) dysfunction is fundamental to the diagnosis and understanding of disease pathogenesis in motor neuron disease (MND). The clinical assessment of UMN dysfunction may be difficult, particularly in the setting of severe muscle weakness. From a physiological perspective, transcranial magnetic stimulation (TMS) techniques provide objective biomarkers of UMN dysfunction in MND and may also be useful to interrogate cortical and network function. Single, paired- and triple pulse TMS techniques have yielded novel diagnostic and prognostic biomarkers in MND, and have provided important pathogenic insights, particularly pertaining to site of disease onset. Cortical hyperexcitability, as heralded by reduced short interval intracortical inhibition (SICI) and increased short interval intracortical facilitation, has been associated with the onset of lower motor neuron degeneration, along with patterns of disease spread, development of specific clinical features such as the split hand phenomenon, and may provide an indication about the rate of disease progression. Additionally, reduction of SICI has emerged as a potential diagnostic aid in MND. The triple stimulation technique (TST) was shown to enhance the diagnostic utility of conventional TMS measures in detecting UMN dysfunction in MND. Separately, sophisticated brain imaging techniques have uncovered novel biomarkers of neurodegeneration that have bene associated with progression. The present review will discuss the utility of TMS and brain neuroimaging derived biomarkers of UMN dysfunction in MND, focusing on recently developed TMS techniques and advanced neuroimaging modalities that interrogate structural and functional integrity of the corticomotoneuronal system, with an emphasis on pathogenic, diagnostic, and prognostic utility.
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Affiliation(s)
- Thanuja Dharmadasa
- Department of Neurology, The Royal Melbourne Hospital City Campus, Parkville, Victoria, Australia
| | - Nathan Pavey
- Brain and Nerve Research Center, The University of Sydney, Sydney, Australia
| | - Sicong Tu
- Brain and Mind Centre, The University of Sydney, and Department of Neurology, Royal Prince Alfred Hospital, Australia
| | - Parvathi Menon
- Brain and Nerve Research Center, The University of Sydney, Sydney, Australia
| | - William Huynh
- Brain and Mind Centre, The University of Sydney, and Department of Neurology, Royal Prince Alfred Hospital, Australia
| | - Colin J Mahoney
- Brain and Mind Centre, The University of Sydney, and Department of Neurology, Royal Prince Alfred Hospital, Australia
| | - Hannah C Timmins
- Brain and Mind Centre, The University of Sydney, and Department of Neurology, Royal Prince Alfred Hospital, Australia
| | - Mana Higashihara
- Department of Neurology, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan
| | - Mehdi van den Bos
- Brain and Nerve Research Center, The University of Sydney, Sydney, Australia
| | - Kazumoto Shibuya
- Neurology, Chiba University, Graduate School of Medicine, Chiba, Japan
| | - Satoshi Kuwabara
- Neurology, Chiba University, Graduate School of Medicine, Chiba, Japan
| | - Julian Grosskreutz
- Precision Neurology, Excellence Cluster Precision Medicine in Inflammation, University of Lübeck, University Hospital Schleswig-Holstein Campus, Lübeck, Germany
| | - Matthew C Kiernan
- Brain and Mind Centre, The University of Sydney, and Department of Neurology, Royal Prince Alfred Hospital, Australia
| | - Steve Vucic
- Brain and Nerve Research Center, The University of Sydney, Sydney, Australia.
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Anders JPV, Neltner TJ, Smith RW, Arnett JE, Housh TJ, Schmidt RJ, Johnson GO. Unilateral and Bilateral Isokinetic Leg Extensions Exhibit No Differences in Neuromuscular Excitation Under Maximal and Fatiguing Conditions. J Strength Cond Res 2024; 38:474-480. [PMID: 38090801 DOI: 10.1519/jsc.0000000000004652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
Abstract
Anders, JPV, Neltner, TJ, Smith, RW, Arnett, JE, Housh, TJ, Schmidt, RJ, and Johnson, GO. Unilateral and bilateral isokinetic leg extensions exhibit no differences in neuromuscular activation under maximal and fatiguing conditions. J Strength Cond Res 38(3): 474–480, 2024—The bilateral deficit is a phenomenon where force production during a bilateral (BL) muscle action is less than the sum of force produced when the muscle action is performed unilaterally (UL) with both limbs. The purpose of this study was to compare peak force, electromyographic (EMG) amplitude (AMP), and mean power frequency (MPF) of the nondominant leg between UL and BL isokinetic leg extensions. Eleven recreationally trained men (mean ± SD; age = 20.8 ± 1.7 years; body mass = 84.0 ± 16.2 kg; height = 179.3 ± 7.2 cm) volunteered to participate in this study. The 2 test visits included UL and BL maximal isokinetic leg extensions at 180°·second−1 followed by a fatiguing task of either 50 UL or 25 UL followed immediately by 25 BL (ULBL) maximal, isokinetic leg extensions at 180°·second−1, in random order on separate days. The results demonstrated a significant (p = 0.015,
= 0.460) bilateral deficit in force (UL = 56.29 ± 11.20 kg; BL = 50.32 ± 7.35 kg; d = 0.63; 95% CI [1.42, 10.52]) but no significant bilateral deficit in EMG AMP (p = 0.892,
= 0.002). The peak force during the fatiguing task demonstrated a significant main effect for repetition (p < 0.001,
= 0.943) characterized by a reduced peak force from repetitions 20–50. Similarly, EMG MPF demonstrated a significant main effect for repetition (p < 0.001,
= 0.702) characterized by a reduced EMG MPF from repetitions 35–50. There were no significant effects (p = 0.102–0.387,
= 0.096–0.203) for EMG AMP. These findings suggested that the bilateral deficit was not associated with a neuromuscular deficit and UL muscle actions may be used to potentiate force production of subsequent BL muscle actions.
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Affiliation(s)
- John Paul V Anders
- The Exercise Science Program, Department of Human Sciences, The Ohio State University, Columbus, Ohio; and
| | - Tyler J Neltner
- Exercise Physiology Laboratory, Department of Nutrition and Health Sciences, The University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Robert W Smith
- Exercise Physiology Laboratory, Department of Nutrition and Health Sciences, The University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Jocelyn E Arnett
- Exercise Physiology Laboratory, Department of Nutrition and Health Sciences, The University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Terry J Housh
- Exercise Physiology Laboratory, Department of Nutrition and Health Sciences, The University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Richard J Schmidt
- Exercise Physiology Laboratory, Department of Nutrition and Health Sciences, The University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Glen O Johnson
- Exercise Physiology Laboratory, Department of Nutrition and Health Sciences, The University of Nebraska-Lincoln, Lincoln, Nebraska
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Koponen LM, Martinez M, Wood E, Murphy DLK, Goetz SM, Appelbaum LG, Peterchev AV. Transcranial magnetic stimulation input-output curve slope differences suggest variation in recruitment across muscle representations in primary motor cortex. Front Hum Neurosci 2024; 18:1310320. [PMID: 38384332 PMCID: PMC10879434 DOI: 10.3389/fnhum.2024.1310320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 01/29/2024] [Indexed: 02/23/2024] Open
Abstract
Measurement of the input-output (IO) curves of motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) can be used to assess corticospinal excitability and motor recruitment. While IO curves have been used to study disease and pharmacology, few studies have compared the IO curves across the body. This study sought to characterize IO curve parameters across the dominant and non-dominant sides of upper and lower limbs in healthy participants. Laterality preferences were assessed in eight healthy participants and IO curves were measured bilaterally for the first dorsal interosseous (FDI), biceps brachii (BB), and tibialis anterior (TA) muscles. Results show that FDI has lower motor threshold than BB which is, in turn, lower than TA. In addition, both BB and TA have markedly shallower logarithmic IO curve slopes from small to large MEP responses than FDI. After normalizing these slopes by their midpoints to account for differences in motor thresholds, which could result from geometric factors such as the target depth, large differences in logarithmic slopes remain present between all three muscles. The differences in slopes between the muscles could not be explained by differences in normalized IO curve spreads, which relate to the extent of the cortical representation and were comparable across the muscles. The IO curve differences therefore suggest muscle-dependent variations in TMS-evoked recruitment across the primary motor cortex, which should be considered when utilizing TMS-evoked MEPs to study disease states and treatment effects.
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Affiliation(s)
- Lari M. Koponen
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, United States
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, UK
| | - Miles Martinez
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, United States
- Center for Cognitive Neuroscience, Duke University, Durham, NC, United States
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, United States
| | - Eleanor Wood
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, United States
| | - David L. K. Murphy
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, United States
| | - Stefan M. Goetz
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, United States
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, United States
- Department of Neurosurgery, Duke University, Durham, NC, United States
| | - Lawrence G. Appelbaum
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, United States
- Department of Psychiatry, University of California, San Diego, San Diego, CA, United States
| | - Angel V. Peterchev
- Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, United States
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, United States
- Department of Neurosurgery, Duke University, Durham, NC, United States
- Department of Biomedical Engineering, Duke University, Durham, NC, United States
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Vucic S, Stanley Chen KH, Kiernan MC, Hallett M, Benninger DH, Di Lazzaro V, Rossini PM, Benussi A, Berardelli A, Currà A, Krieg SM, Lefaucheur JP, Long Lo Y, Macdonell RA, Massimini M, Rosanova M, Picht T, Stinear CM, Paulus W, Ugawa Y, Ziemann U, Chen R. Clinical diagnostic utility of transcranial magnetic stimulation in neurological disorders. Updated report of an IFCN committee. Clin Neurophysiol 2023; 150:131-175. [PMID: 37068329 PMCID: PMC10192339 DOI: 10.1016/j.clinph.2023.03.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/28/2023] [Accepted: 03/09/2023] [Indexed: 03/31/2023]
Abstract
The review provides a comprehensive update (previous report: Chen R, Cros D, Curra A, Di Lazzaro V, Lefaucheur JP, Magistris MR, et al. The clinical diagnostic utility of transcranial magnetic stimulation: report of an IFCN committee. Clin Neurophysiol 2008;119(3):504-32) on clinical diagnostic utility of transcranial magnetic stimulation (TMS) in neurological diseases. Most TMS measures rely on stimulation of motor cortex and recording of motor evoked potentials. Paired-pulse TMS techniques, incorporating conventional amplitude-based and threshold tracking, have established clinical utility in neurodegenerative, movement, episodic (epilepsy, migraines), chronic pain and functional diseases. Cortical hyperexcitability has emerged as a diagnostic aid in amyotrophic lateral sclerosis. Single-pulse TMS measures are of utility in stroke, and myelopathy even in the absence of radiological changes. Short-latency afferent inhibition, related to central cholinergic transmission, is reduced in Alzheimer's disease. The triple stimulation technique (TST) may enhance diagnostic utility of conventional TMS measures to detect upper motor neuron involvement. The recording of motor evoked potentials can be used to perform functional mapping of the motor cortex or in preoperative assessment of eloquent brain regions before surgical resection of brain tumors. TMS exhibits utility in assessing lumbosacral/cervical nerve root function, especially in demyelinating neuropathies, and may be of utility in localizing the site of facial nerve palsies. TMS measures also have high sensitivity in detecting subclinical corticospinal lesions in multiple sclerosis. Abnormalities in central motor conduction time or TST correlate with motor impairment and disability in MS. Cerebellar stimulation may detect lesions in the cerebellum or cerebello-dentato-thalamo-motor cortical pathways. Combining TMS with electroencephalography, provides a novel method to measure parameters altered in neurological disorders, including cortical excitability, effective connectivity, and response complexity.
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Affiliation(s)
- Steve Vucic
- Brain, Nerve Research Center, The University of Sydney, Sydney, Australia.
| | - Kai-Hsiang Stanley Chen
- Department of Neurology, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan
| | - Matthew C Kiernan
- Brain and Mind Centre, The University of Sydney; and Department of Neurology, Royal Prince Alfred Hospital, Australia
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, Maryland, United States
| | - David H Benninger
- Department of Neurology, University Hospital of Lausanne (CHUV), Switzerland
| | - Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, University Campus Bio-Medico of Rome, Rome, Italy
| | - Paolo M Rossini
- Department of Neurosci & Neurorehab IRCCS San Raffaele-Rome, Italy
| | - Alberto Benussi
- Centre for Neurodegenerative Disorders, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Alfredo Berardelli
- IRCCS Neuromed, Pozzilli; Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Antonio Currà
- Department of Medico-Surgical Sciences and Biotechnologies, Alfredo Fiorini Hospital, Sapienza University of Rome, Terracina, LT, Italy
| | - Sandro M Krieg
- Department of Neurosurgery, Technical University Munich, School of Medicine, Klinikum rechts der Isar, Munich, Germany
| | - Jean-Pascal Lefaucheur
- Univ Paris Est Creteil, EA4391, ENT, Créteil, France; Clinical Neurophysiology Unit, Henri Mondor Hospital, AP-HP, Créteil, France
| | - Yew Long Lo
- Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Singapore, and Duke-NUS Medical School, Singapore
| | | | - Marcello Massimini
- Dipartimento di Scienze Biomediche e Cliniche, Università degli Studi di Milano, Milan, Italy; Istituto Di Ricovero e Cura a Carattere Scientifico, Fondazione Don Carlo Gnocchi, Milan, Italy
| | - Mario Rosanova
- Department of Biomedical and Clinical Sciences University of Milan, Milan, Italy
| | - Thomas Picht
- Department of Neurosurgery, Charité-Universitätsmedizin Berlin, Cluster of Excellence: "Matters of Activity. Image Space Material," Humboldt University, Berlin Simulation and Training Center (BeST), Charité-Universitätsmedizin Berlin, Germany
| | - Cathy M Stinear
- Department of Medicine Waipapa Taumata Rau, University of Auckland, Auckland, Aotearoa, New Zealand
| | - Walter Paulus
- Department of Neurology, Ludwig-Maximilians-Universität München, München, Germany
| | - Yoshikazu Ugawa
- Department of Human Neurophysiology, School of Medicine, Fukushima Medical University, Japan
| | - Ulf Ziemann
- Department of Neurology and Stroke, Eberhard Karls University of Tübingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany; Hertie Institute for Clinical Brain Research, Eberhard Karls University of Tübingen, Otfried-Müller-Straße 27, 72076 Tübingen, Germany
| | - Robert Chen
- Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital-UHN, Division of Neurology-University of Toronto, Toronto Canada
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Su B, Jia Y, Zhang L, Li D, Shen Q, Wang C, Chen Y, Gao F, Wei J, Huang G, Liu H, Wang L. Reliability of TMS measurements using conventional hand-hold method with different numbers of stimuli for tibialis anterior muscle in healthy adults. Front Neural Circuits 2022; 16:986669. [PMID: 36247728 PMCID: PMC9563236 DOI: 10.3389/fncir.2022.986669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 09/15/2022] [Indexed: 11/28/2022] Open
Abstract
Objective: The objective of this study was to determine the reliability of corticomotor excitability measurements using the conventional hand-hold transcranial magnetic stimulation (TMS) method for the tibialis anterior (TA) muscle in healthy adults and the number of stimuli required for reliable assessment. Methods: Forty healthy adults participated in three repeated sessions of corticomotor excitability assessment in terms of resting motor threshold (rMT), slope of recruitment curve (RC), peak motor evoked potential amplitude (pMEP), and MEP latency using conventional TMS method. The first two sessions were conducted with a rest interval of 1 h, and the last session was conducted 7–10 days afterward. With the exception of rMT, the other three outcomes measure elicited with the block of first 3–10 stimuli were analyzed respectively. The within-day (session 1 vs. 2) and between-day (session 1 vs. 3) reliability for all four outcome measures were assessed using intraclass correlation coefficient (ICC), standard error of measurement, and minimum detectable difference at 95% confidence interval. Results: Good to excellent within-day and between-day reliability was found for TMS-induced outcome measures examined using 10 stimuli (ICC ≥ 0.823), except in pMEP, which showed between-day reliability at moderate level (ICC = 0.730). The number of three stimuli was adequate to achieve minimum acceptable within-day reliability for all TMS-induced parameters and between-day reliability for MEP latency. With regard to between-day reliability of RC slope and pMEP, at least seven and nine stimuli were recommended respectively. Conclusion: Our findings indicated the high reliability of corticomotor excitability measurement by TMS with adequate number of stimuli for the TA muscle in healthy adults. This result should be interpreted with caveats for the specific methodological choices, equipment setting, and the characteristics of the sample in the current study. Clinical Trial Registration:http://www.chictr.org.cn, identifier ChiCTR2100045141.
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Affiliation(s)
- Bin Su
- School of Exercise and Health, Shanghai University of Sport, Shanghai, China
- Department of Rehabilitation, Wuxi Central Rehabilitation Hospital, Wuxi, China
| | - Yanbing Jia
- School of Rehabilitation Medicine, Jiangsu Vocational College of Medicine, Yancheng, China
| | - Li Zhang
- Department of Rehabilitation, Wuxi Central Rehabilitation Hospital, Wuxi, China
| | - Duo Li
- Neuro-Rehabilitation Center, JORU Rehabilitation Hospital, Yixing, China
| | - Qianqian Shen
- Department of Rehabilitation, Wuxi Central Rehabilitation Hospital, Wuxi, China
| | - Chun Wang
- Neuro-Rehabilitation Center, JORU Rehabilitation Hospital, Yixing, China
| | - Yating Chen
- Department of Rehabilitation, Wuxi Central Rehabilitation Hospital, Wuxi, China
| | - Fanglan Gao
- Department of Rehabilitation, Wuxi Central Rehabilitation Hospital, Wuxi, China
| | - Jing Wei
- Neuro-Rehabilitation Center, JORU Rehabilitation Hospital, Yixing, China
| | - Guilan Huang
- Department of Rehabilitation, Wuxi Central Rehabilitation Hospital, Wuxi, China
| | - Hao Liu
- School of Rehabilitation Medicine, Jiangsu Vocational College of Medicine, Yancheng, China
- *Correspondence: Lin Wang Hao Liu
| | - Lin Wang
- School of Exercise and Health, Shanghai University of Sport, Shanghai, China
- *Correspondence: Lin Wang Hao Liu
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Increased short interval intracortical inhibition in participants with previous hamstring strain injury. Eur J Appl Physiol 2021; 122:357-369. [PMID: 34729636 DOI: 10.1007/s00421-021-04839-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 10/27/2021] [Indexed: 10/19/2022]
Abstract
PURPOSE Cortical mechanisms may contribute to weakness in participants with previous hamstring strain injury. This study aims to examine intra-cortical inhibition (SICI) and corticospinal excitability in previously injured participants. METHODS In this cross-sectional study, TMS was used to examine SICI, silent period, silent period: MEP ratios and area under the stimulus response curve in the biceps femoris and medial hamstrings. Comparisons were made between participants with (n = 10) and without (n = 10) previous hamstring strain injury. Motor threshold and isometric knee flexor strength were also compared between participants and the relationship between strength and SICI in control and previously injured participants was examined. RESULTS Isometric knee flexor strength was lower in previously injured limbs compared with control limbs (mean difference = - 41 Nm (- 26%) [95% CI = - 80 to - 2 Nm], p = 0.04, Cohen's d = - 1.27) and contralateral uninjured limbs (mean difference = - 23 Nm (- 17%), [95% CI = - 40 to - 6 Nm], p = 0.01, Cohen's d = - 0.57). Previously injured limbs exhibited smaller responses to paired pulse stimulation (i.e. greater levels of SICI) in the biceps femoris compared with control limbs (mean difference = - 19%, [95% CI = - 34 to - 5%], p = 0.007, Cohen's d = - 1.33). Isometric knee flexor strength was associated with the level of SICI recorded in the biceps femoris in previously injured participants (coefficient = 23 Nm [95% CI = 7-40 Nm], adjusted R2 = 0.31, p = 0.01). There were no differences in markers of corticospinal excitability between previously injured and control limbs (all p > 0.24, all Cohen's d < 0.40). CONCLUSION Athletes with previous injury in the biceps femoris exhibit increased SICI in this muscle compared with control participants. Increased SICI is related to lower levels of hamstring strength, and rehabilitation programs targeting the removal of intra-cortical inhibition should be considered.
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Suzuki YI, Ma Y, Shibuya K, Misawa S, Suichi T, Tsuneyama A, Nakamura K, Matamala JM, Dharmadasa T, Vucic S, Fan D, Kiernan MC, Kuwabara S. Effect of racial background on motor cortical function as measured by threshold tracking transcranial magnetic stimulation. J Neurophysiol 2021; 126:840-844. [PMID: 34406906 DOI: 10.1152/jn.00083.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A previous study using traditional paired-pulse TMS methods (amplitude-tracking) has reported differences in resting motor threshold (RMT) and short-interval intracortical inhibition (SICI) between healthy subjects of Caucasian and Han Chinese backgrounds, probably due to differences in the skull shape. The amplitude-tracking method delivers stimuli with constant intensity and causes substantial variabilities in motor-evoked potential amplitudes. To overcome this variability, threshold tracking transcranial magnetic stimulation (TT-TMS) has been developed. The present study aimed to investigate whether racial differences in motor cortical function exist, using TT-TMS. A total of 83 healthy volunteers (30 Caucasians, 25 Han Chinese, and 28 Japanese) were included in the present series. In TT-TMS and nerve conduction studies, electrodes were placed on the dominant limb, with measures recorded from the abductor pollicis brevis muscle. Stimulations were delivered with a circular coil, directly above the primary motor cortex. There were no significant differences at all the SICI intervals between races. Similarly, there were no significant differences in other measures of excitability including mean RMT, intracortical facilitation, and cortical silent period. Contrary to traditional amplitude-tracking TMS, motor cortical excitability and thereby motor cortical function is minimally influenced by racial differences when measured by TT-TMS. Recent studies have disclosed that SICI measured by TT-TMS differentiates amyotrophic lateral sclerosis (ALS) from ALS mimic disorders, with high sensitivity and specificity, in Caucasians. This study suggested that TT-TMS can be applied for the ALS diagnosis in Asian patients, as well as Caucasians.NEW & NOTEWORTHY Threshold tracking transcranial magnetic stimulation (TT-TMS) was applied for Caucasians, Han Chinese, and Japanese. No significant differences were found in TMS excitability indexes among races. Recent studies have disclosed that TT-TMS indexes differentiate amyotrophic lateral sclerosis (ALS) from ALS mimic disorders, with high sensitivity and specificity, in Caucasians. This study suggested that TT-TMS can be applied for the ALS diagnosis in Asian patients, as well as Caucasians.
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Affiliation(s)
- Yo-Ichi Suzuki
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yan Ma
- Brain and Mind Centre, University of Sydney, Sydney, New South Wales, Australia.,Department of Neurology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia.,Department of Neurology, Peking University Third Hospital, Beijing, China
| | - Kazumoto Shibuya
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan.,Brain and Mind Centre, University of Sydney, Sydney, New South Wales, Australia.,Department of Neurology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Sonoko Misawa
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Tomoki Suichi
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Atsuko Tsuneyama
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Keigo Nakamura
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - José Manuel Matamala
- Brain and Mind Centre, University of Sydney, Sydney, New South Wales, Australia.,Department of Neurology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Thanuja Dharmadasa
- Brain and Mind Centre, University of Sydney, Sydney, New South Wales, Australia.,Department of Neurology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Steve Vucic
- Westmead Clinical School, University of Sydney, Sydney, New South Wales, Australia
| | - Dongsheng Fan
- Department of Neurology, Peking University Third Hospital, Beijing, China
| | - Matthew C Kiernan
- Brain and Mind Centre, University of Sydney, Sydney, New South Wales, Australia
| | - Satoshi Kuwabara
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
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Zhang KL, Yuan H, Wu FF, Pu XY, Liu BZ, Li Z, Li KF, Liu H, Yang Y, Wang YY. Analgesic Effect of Noninvasive Brain Stimulation for Neuropathic Pain Patients: A Systematic Review. Pain Ther 2021; 10:315-332. [PMID: 33751453 PMCID: PMC8119533 DOI: 10.1007/s40122-021-00252-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 02/26/2021] [Indexed: 01/04/2023] Open
Abstract
Introduction The objective of this review is to systematically summarize the consensus on best practices for different NP conditions of the two most commonly utilized noninvasive brain stimulation (NIBS) technologies, repetitive transcranial magnetic stimulation (rTMS), and transcranial direct current stimulation (tDCS). Methods PubMed was searched according to the predetermined keywords and criteria. Only English language studies and studies published up to January 31, 2020 were taken into consideration. Meta-analyses, reviews, and systematic reviews were excluded first, and those related to animal studies or involving healthy volunteers were also excluded. Finally, 29 studies covering 826 NP patients were reviewed. Results The results from the 24 enrolled studies and 736 NP patients indicate that rTMS successfully relieved the pain symptoms of 715 (97.1%) NP patients. Also, five studies involving 95 NP patients (81.4%) also showed that tDCS successfully relieved NP. In the included studied, the M1 region plays a key role in the analgesic treatment of NIBS. The motor evoked potentials (MEPs), the 10–20 electroencephalography system (EEG 10/20 system), and neuro-navigation methods are used in clinical practice to locate therapeutic targets. Based on the results of the review, the stimulation parameters of rTMS that best induce an analgesic effect are a stimulation frequency of 10–20 Hz, a stimulation intensity of 80–120% of RMT, 1000–2000 pulses, and 5–10 sessions, and the most effective parameters of tDCS are a current intensity of 2 mA, a session duration of 20–30 min, and 5–10 sessions. Conclusions Our systematically reviewed the evidence for positive and negative responses to rTMS and tDCS for NP patient care and underscores the analgesic efficacy of NIBS in patients with NP. The treatment of NP should allow the design of optimal treatments for individual patients.
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Affiliation(s)
- Kun-Long Zhang
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Demonstration Center for Experimental Preclinical Medicine Education, Air Force Medical University, Xi'an, 710032, China.,Department of Rehabilitation Medicine, Xi-Jing Hospital, Air Force Medical University, Xi'an, 710032, China
| | - Hua Yuan
- Department of Rehabilitation Medicine, Xi-Jing Hospital, Air Force Medical University, Xi'an, 710032, China
| | - Fei-Fei Wu
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Demonstration Center for Experimental Preclinical Medicine Education, Air Force Medical University, Xi'an, 710032, China
| | - Xue-Yin Pu
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Demonstration Center for Experimental Preclinical Medicine Education, Air Force Medical University, Xi'an, 710032, China
| | - Bo-Zhi Liu
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Demonstration Center for Experimental Preclinical Medicine Education, Air Force Medical University, Xi'an, 710032, China
| | - Ze Li
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Demonstration Center for Experimental Preclinical Medicine Education, Air Force Medical University, Xi'an, 710032, China
| | - Kai-Feng Li
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Demonstration Center for Experimental Preclinical Medicine Education, Air Force Medical University, Xi'an, 710032, China
| | - Hui Liu
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Demonstration Center for Experimental Preclinical Medicine Education, Air Force Medical University, Xi'an, 710032, China.,Department of Human Anatomy, Yan-An University, Yan'an, 716000, China
| | - Yi Yang
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Demonstration Center for Experimental Preclinical Medicine Education, Air Force Medical University, Xi'an, 710032, China.,Department of Human Anatomy, Yan-An University, Yan'an, 716000, China
| | - Ya-Yun Wang
- Specific Lab for Mitochondrial Plasticity Underlying Nervous System Diseases, National Demonstration Center for Experimental Preclinical Medicine Education, Air Force Medical University, Xi'an, 710032, China. .,State Key Laboratory of Military Stomatology, School of Stomatology, The Fourth Military Medical University, Xi'an, China.
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9
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Proessl F, Canino MC, Beckner ME, Sinnott AM, Eagle SR, LaGoy AD, Conkright WR, Sterczala AJ, Connaboy C, Ferrarelli F, Germain A, Nindl BC, Flanagan SD. Characterizing off-target corticospinal responses to double-cone transcranial magnetic stimulation. Exp Brain Res 2021; 239:1099-1110. [PMID: 33547521 DOI: 10.1007/s00221-021-06044-5] [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: 10/07/2020] [Accepted: 01/18/2021] [Indexed: 10/22/2022]
Abstract
INTRODUCTION The double-cone coil (D-CONE) is frequently used in transcranial magnetic stimulation (TMS) experiments that target the motor cortex (M1) lower-limb representation. Anecdotal evidence and modeling studies have shed light on the off-target effects of D-CONE TMS but the physiological extent remains undetermined. PURPOSE To characterize the off-target effects of D-CONE TMS based on bilateral corticospinal responses in the legs and hands. METHODS Thirty (N = 30) participants (9 women, age: 26 ± 5yrs) completed a stimulus-response curve procedure with D-CONE TMS applied to the dominant vastus lateralis (cVL) and motor-evoked potentials (MEPs) recorded in each active VL and resting first dorsal interosseous (FDI). As a positive control (CON), the dominant FDI was directly targeted with a figure-of-eight coil and MEPs were similarly recorded in each active FDI and resting VL. MEPMAX, V50 and MEP latencies were compared with repeated-measures ANOVAs or mixed-effects analysis and Bonferroni-corrected pairwise comparisons. RESULTS Off-target responses were evident in all muscles, with similar MEPMAX in the target (cVL) and off-target (iVL) leg (p = 0.99) and cFDI compared with CON (p = 0.99). cFDI and CON MEPMAX were greater than iFDI (p < 0.01). A main effect of target (p < 0.001) indicated that latencies were shorter with CON but similar in all muscles with D-CONE. DISCUSSION Concurrent MEP recordings in bilateral upper- and lower-extremity muscles confirm that lower-limb D-CONE TMS produces substantial distance-dependent off-target effects. In addition to monitoring corticospinal responses in off-target muscles to improve targeting accuracy in real-time, future studies may incorporate off-target information into statistical models post-hoc.
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Affiliation(s)
- F Proessl
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - M C Canino
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - M E Beckner
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - A M Sinnott
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - S R Eagle
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - A D LaGoy
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA.,Department of Psychiatry, University of Pittsburgh Medical School, 3811 O'Hara Street, Pittsburgh, PA, 15213, USA
| | - W R Conkright
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - A J Sterczala
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - C Connaboy
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - F Ferrarelli
- Department of Psychiatry, University of Pittsburgh Medical School, 3811 O'Hara Street, Pittsburgh, PA, 15213, USA
| | - A Germain
- Department of Psychiatry, University of Pittsburgh Medical School, 3811 O'Hara Street, Pittsburgh, PA, 15213, USA
| | - B C Nindl
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - S D Flanagan
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA.
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10
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Sivaramakrishnan A, Madhavan S. Reliability of transcallosal inhibition measurements for the lower limb motor cortex in stroke. Neurosci Lett 2021; 743:135558. [PMID: 33352282 PMCID: PMC7855415 DOI: 10.1016/j.neulet.2020.135558] [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: 10/06/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 11/29/2022]
Abstract
Transcallosal inhibition (TCI) is a measure of between-hemisphere inhibitory control that can be evaluated with the ipsilateral silent period (iSP) transcranial magnetic stimulation (TMS) paradigm. The study of iSP for the lower extremity has been limited possibly due to the close orientation of the lower extremity motor representations. Change in TCI can provide insights into pathophysiological mechanisms underlying the asymmetry in corticomotor excitability in stroke. Here, we describe a method for iSP quantification and report reliability of iSP parameters for the tibialis anterior (TA) muscle in stroke. 26 individuals with stroke attended three sessions where single pulse TMS was used to measure TCI from the lesioned to non-lesioned hemisphere. A double cone coil was used for stimulating the ipsilateral motor cortex while the participant maintained an isometric contraction of the non-paretic TA. Absolute and relative reliability were computed for iSP latency, duration and area. iSP latency showed the lowest measurement error (absolute reliability) and iSP latency, duration and area showed good relative reliability (intraclass correlation coefficients > 0.6). This study suggests that iSP parameters for the tibialis anterior are reliable and attempts to provide a guideline for evaluating TCI for the lower extremity in stroke and other clinical populations.
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Affiliation(s)
- Anjali Sivaramakrishnan
- Brain Plasticity Lab, Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago (UIC), USA; Graduate Program in Rehabilitation Sciences, College of Applied Health Sciences, UIC, USA
| | - Sangeetha Madhavan
- Brain Plasticity Lab, Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago (UIC), USA.
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11
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Ørskov S, Bostock H, Howells J, Pugdahl K, Fuglsang-Frederiksen A, Nielsen CSZ, Cengiz B, Samusyte G, Koltzenburg M, Tankisi H. Comparison of figure-of-8 and circular coils for threshold tracking transcranial magnetic stimulation measurements. Neurophysiol Clin 2021; 51:153-160. [PMID: 33468370 DOI: 10.1016/j.neucli.2021.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/05/2021] [Accepted: 01/05/2021] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES The transcranial magnetic stimulation (TMS) technique of threshold-tracking short-interval intracortical inhibition (T-SICI) has been proposed as a diagnostic tool for amyotrophic lateral sclerosis (ALS). Most of these studies have used a circular coil, whereas a figure-of-8 coil is usually recommended for paired-pulse TMS measurements. The aim of this study was to compare figure-of-8 and circular coils for T-SICI in the upper limb, with special attention to reproducibility, and the pain or discomfort experienced by the subjects. METHODS Twenty healthy subjects (aged: 45.5 ± 6.7, mean ± SD, 9 females, 11 males) underwent two examinations with each coil, in morning and afternoon sessions on the same day, with T-SICI measured at interstimulus intervals (ISIs) from 1-7 ms. After each examination the subjects rated degree of pain/discomfort from 0 to 10 using a numerical rating scale (NRS). RESULTS Mean T-SICI was higher for the figure-of-8 than for the circular coil at ISI of 2 ms (p < 0.05) but did not differ at other ISIs. Intra-subject variability did not differ between coils, but mean inhibition from 1-3.5 ms was less variable between subjects with the figure-of-8 coil (SD 7.2% vs. 11.2% RMT, p < 0.05), and no such recordings were without inhibition (vs. 6 with the circular coil). The subjects experienced less pain/discomfort with the figure-of-8 coil (mean NRS: 1.9 ± 1.28 vs 2.8 ± 1.60, p < 0.005). DISCUSSION The figure-of-8 coil may have better applicability in patients, due to the lower incidence of lack of inhibition in healthy subjects, and the lower experience of pain or discomfort.
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Affiliation(s)
- Søren Ørskov
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
| | - Hugh Bostock
- Department of Clinical Neurophysiology, National Hospital for Neurology and Neurosurgery, Queen Square, WC1N 3BG, London, United Kingdom
| | - James Howells
- Central Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Kirsten Pugdahl
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
| | | | | | - Bülent Cengiz
- Department of Neurology, Gazi University Faculty of Medicine, Beşevler, 06500, Ankara, Turkey
| | - Gintaute Samusyte
- Department of Neurology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Martin Koltzenburg
- Department of Clinical Neurophysiology, National Hospital for Neurology and Neurosurgery, Queen Square, WC1N 3BG, London, United Kingdom; Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, WC1N 3BG, London, United Kingdom
| | - Hatice Tankisi
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark.
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12
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Hupfeld KE, Swanson CW, Fling BW, Seidler RD. TMS-induced silent periods: A review of methods and call for consistency. J Neurosci Methods 2020; 346:108950. [PMID: 32971133 PMCID: PMC8276277 DOI: 10.1016/j.jneumeth.2020.108950] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/24/2020] [Accepted: 09/15/2020] [Indexed: 12/31/2022]
Abstract
Transcranial magnetic stimulation (TMS)-induced silent periods provide an in vivo measure of human motor cortical inhibitory function. Cortical silent periods (cSP, also sometimes referred to as contralateral silent periods) and ipsilateral silent periods (iSP) may change with advancing age and disease and can provide insight into cortical control of the motor system. The majority of past silent period work has implemented largely varying methodology, sometimes including subjective analyses and incomplete methods descriptions. This limits reproducibility of silent period work and hampers comparisons of silent period measures across studies. Here, we discuss methodological differences in past silent period work, highlighting how these choices affect silent period outcome measures. We also outline challenges and possible solutions for measuring silent periods in the unique case of the lower limbs. Finally, we provide comprehensive recommendations for collection, analysis, and reporting of future silent period studies.
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Affiliation(s)
- K E Hupfeld
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - C W Swanson
- Department of Health & Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - B W Fling
- Department of Health & Exercise Science, Colorado State University, Fort Collins, CO, USA; Molecular, Cellular, and Integrative Neuroscience Program, Colorado State University, Fort Collins, CO, USA
| | - R D Seidler
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA; Department of Neurology, University of Florida, Gainesville, FL, USA.
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13
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Dharmadasa T, Howells J, Matamala JM, Simon NG, Burke D, Vucic S, Kiernan MC. Cortical inexcitability defines an adverse clinical profile in amyotrophic lateral sclerosis. Eur J Neurol 2020; 28:90-97. [PMID: 32902860 PMCID: PMC7820947 DOI: 10.1111/ene.14515] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 09/02/2020] [Indexed: 12/11/2022]
Abstract
Background and purpose In amyotrophic lateral sclerosis, studies using threshold‐tracking transcranial magnetic stimulation (TMS) have identified corticomotoneuronal dysfunction as a key pathogenic mechanism. Some patients, however, display no motor response at maximal TMS intensities, termed here an ‘inexcitable’ motor cortex. The extent to which this cortical difference impacts clinical outcomes remains unclear. The aim of this study was to determine the clinical profile of patients with inexcitability to TMS. Methods Motor cortex excitability was evaluated using TMS. Patients in whom a motor evoked potential could not be recorded in one or more limbs at maximal TMS intensities were classified as four‐limb or partially inexcitable. Demographic information, clinical variables and survival data were analysed. Results From 133 patients, 40 were identified with inexcitability. Patients with four‐limb inexcitability were younger (P = 0.03) and had lower‐limb disease onset (64%), greater functional disability (P < 0.001) and faster disease progression (P = 0.02), particularly if inexcitability developed within 1 year of symptoms (P < 0.01). Patients with partial inexcitability had higher resting motor thresholds compared to the excitable cohort (P < 0.01), but averaged short‐interval intracortical inhibition was similar (P = 0.5). Mean survival was reduced if inexcitability involved all limbs within 12 months of symptom onset (P = 0.04). Conclusion Amyotrophic lateral sclerosis patients with inexcitability of all four limbs to TMS have a distinct clinical profile of younger age and lower‐limb onset. Importantly, these patients display a more malignant disease trajectory, with faster progression, greater functional disability and reduced survival when occurring in early disease. This measure may provide an important prognostic marker in amyotrophic lateral sclerosis.
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Affiliation(s)
- T Dharmadasa
- Brain and Mind Centre, University of Sydney, Sydney, NSW, Australia
| | - J Howells
- Brain and Mind Centre, University of Sydney, Sydney, NSW, Australia
| | - J M Matamala
- Brain and Mind Centre, University of Sydney, Sydney, NSW, Australia
| | - N G Simon
- St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - D Burke
- Sydney Medical School, University of Sydney, Sydney, NSW, Australia.,Department of Neurology, Royal Prince Alfred Hospital, Sydney, NSW, Australia
| | - S Vucic
- Westmead Clinical School, University of Sydney, Sydney, NSW, Australia
| | - M C Kiernan
- Brain and Mind Centre, University of Sydney, Sydney, NSW, Australia.,Department of Neurology, Royal Prince Alfred Hospital, Sydney, NSW, Australia
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14
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Davies JL. Using transcranial magnetic stimulation to map the cortical representation of lower-limb muscles. Clin Neurophysiol Pract 2020; 5:87-99. [PMID: 32455179 PMCID: PMC7235616 DOI: 10.1016/j.cnp.2020.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/30/2020] [Accepted: 04/18/2020] [Indexed: 01/25/2023] Open
Abstract
Objective To evaluate the extent to which transcranial magnetic stimulation (TMS) can identify discrete cortical representation of lower-limb muscles in healthy individuals. Methods Motor evoked potentials were recorded from resting vastus medialis, rectus femoris, vastus lateralis, medial and lateral hamstring, and medial and lateral gastrocnemius muscles on the right leg of 16 young healthy adults using bipolar surface electrodes. TMS was delivered through a 110-mm double-cone coil at 63 sites over the left hemisphere. Location and size of cortical representation and number of discrete peaks were quantified. Results Within the quadriceps group there was a main effect of muscle on anterior-posterior centre of gravity (p = 0.010), but the magnitude of the difference was small. There was also a main effect of muscle on medial-lateral hotspot (p = 0.027) and map volume (p = 0.047), but no post-hoc tests were significant. The topography of each lower-limb muscle was complex and variable across individuals. Conclusions TMS delivered with a 110-mm double-cone coil could not reliably identify discrete cortical representations of resting lower-limb muscles when responses were measured using bipolar surface electromyography. Significance The characteristics of the cortical representation provide a basis against which to evaluate cortical reorganisation in clinical populations.
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Affiliation(s)
- Jennifer L Davies
- School of Healthcare Sciences, Cardiff University, United Kingdom.,Biomechanics and Bioengineering Research Centre Versus Arthritis, Cardiff University, United Kingdom.,Cardiff University Brain Research Imaging Centre, Cardiff University, United Kingdom
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15
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Dharmadasa T, Matamala JM, Howells J, Vucic S, Kiernan MC. Early focality and spread of cortical dysfunction in amyotrophic lateral sclerosis: A regional study across the motor cortices. Clin Neurophysiol 2020; 131:958-966. [DOI: 10.1016/j.clinph.2019.11.057] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/13/2019] [Accepted: 11/18/2019] [Indexed: 11/15/2022]
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16
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Sustained Maximal Voluntary Contractions Elicit Different Neurophysiological Responses in Upper- and Lower-Limb Muscles in Men. Neuroscience 2019; 422:88-98. [DOI: 10.1016/j.neuroscience.2019.09.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 09/20/2019] [Accepted: 09/23/2019] [Indexed: 11/20/2022]
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17
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Rozand V, Senefeld JW, Sundberg CW, Smith AE, Hunter SK. Differential effects of aging and physical activity on corticospinal excitability of upper and lower limb muscles. J Neurophysiol 2019; 122:241-250. [PMID: 31091158 DOI: 10.1152/jn.00077.2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Corticospinal tract excitability can be altered by age, physical activity (PA), and possibly sex, but whether these effects differ between upper and lower limb muscles is unknown. We determined the influence of age, PA, and sex on corticospinal excitability of an upper limb and a lower limb muscle during submaximal contractions by comparing stimulus-response curves of motor evoked potentials (MEPs). Transcranial magnetic stimulation (TMS) was used to evoke stimulus-response curves in active muscles by incrementally increasing the stimulator intensity from below the active motor threshold (AMT) until a plateau in MEP amplitudes was achieved. Stimulus-response curves were analyzed from the first dorsal interosseous (FDI) of 30 young (23.9 ± 3.8 yr) and 33 older (72.6 ± 5.6 yr) men and women and the vastus lateralis (VL) of 13 young (23.2 ± 2.2 yr) and 25 older (72.7 ± 5.5 yr) men and women. Corticospinal excitability was determined by fitting the curves with a four-parameter sigmoidal curve and calculating the maximal slope (slopemax). PA was assessed with triaxial accelerometry, and participants were dichotomized into high-PA (>10,000 steps/day, n = 15) or low-PA (<10,000 steps/day, n = 43) groups. Young adults had larger FDI MEP amplitudes (% maximum amplitude of compound muscle action potential) at higher TMS intensities (120-150% AMT) and greater slopemax than older adults (P < 0.05), with no differences between high- and low-PA groups (P > 0.05). VL MEP amplitudes and slopemax, however, were lower in the high-PA than low-PA participants, with no age or sex differences. These data suggest that aging and PA, but not sex, differentially influence the excitability of the corticospinal tracts projecting to muscles of the upper compared with the lower limb. NEW & NOTEWORTHY Excitability of the corticospinal tract projecting to the first dorsal interosseous assessed with transcranial magnetic stimulation was reduced with age but independent of regular physical activity (steps/day) and sex of the individual. In contrast, corticospinal excitability of the vastus lateralis was not affected by age but was reduced in individuals achieving more than the physical activity recommendations of 10,000 steps/day. Aging and activity differentially affect corticospinal excitability of upper and lower limb muscles.
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Affiliation(s)
- Vianney Rozand
- Laboratoire Interuniversitaire de Biologie de la Motricité, EA 7424, Université de Lyon-Université Jean Monnet Saint-Etienne , Saint-Etienne , France
| | - Jonathon W Senefeld
- Exercise Science Program, Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin
| | - Christopher W Sundberg
- Exercise Science Program, Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin
| | - Ashleigh E Smith
- Alliance for Research in Exercise Nutrition and Activity, School of Health Sciences, University of South Australia , Adelaide, South Australia , Australia.,Cognitive Ageing and Impairment Neurosciences Research Group, School of Psychology and Social Work, University of South Australia , Adelaide, South Australia , Australia
| | - Sandra K Hunter
- Exercise Science Program, Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin
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