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Tankisi H, Versace V, Kuppuswamy A, Cole J. The role of clinical neurophysiology in the definition and assessment of fatigue and fatigability. Clin Neurophysiol Pract 2023; 9:39-50. [PMID: 38274859 PMCID: PMC10808861 DOI: 10.1016/j.cnp.2023.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 11/24/2023] [Accepted: 12/07/2023] [Indexed: 01/27/2024] Open
Abstract
Though a common symptom, fatigue is difficult to define and investigate, occurs in a wide variety of neurological and systemic disorders, with differing pathological causes. It is also often accompanied by a psychological component. As a symptom of long-term COVID-19 it has gained more attention. In this review, we begin by differentiating fatigue, a perception, from fatigability, quantifiable through biomarkers. Central and peripheral nervous system and muscle disorders associated with these are summarised. We provide a comprehensive and objective framework to help identify potential causes of fatigue and fatigability in a given disease condition. It also considers the effectiveness of neurophysiological tests as objective biomarkers for its assessment. Among these, twitch interpolation, motor cortex stimulation, electroencephalography and magnetencephalography, and readiness potentials will be described for the assessment of central fatigability, and surface and needle electromyography (EMG), single fibre EMG and nerve conduction studies for the assessment of peripheral fatigability. The purpose of this review is to guide clinicians in how to approach fatigue, and fatigability, and to suggest that neurophysiological tests may allow an understanding of their origin and interactions. In this way, their differing types and origins, and hence their possible differing treatments, may also be defined more clearly.
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Affiliation(s)
- Hatice Tankisi
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
- Institute of Clinical Medicine, Aarhus University, Denmark
| | - Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Teaching Hospital of the Paracelsus Medical Private University (PMU), Vipiteno-Sterzing, Italy
| | - Annapoorna Kuppuswamy
- Department of Clinical and Movement Neuroscience, Institute of Neurology, University College London, WC1N 3BG London, UK
- Department of Biomedical Sciences, University of Leeds, UK
| | - Jonathan Cole
- Clinical Neurophysiology, University Hospitals Dorset (Poole), UK
- University of Bournemouth, Poole, UK
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2
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van der Groen O, Latella C, Nosaka K, Edwards D, Teo WP, Taylor JL. Corticospinal and intracortical responses from both motor cortices following unilateral concentric versus eccentric contractions. Eur J Neurosci 2023; 57:619-632. [PMID: 36512398 DOI: 10.1111/ejn.15897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/11/2022] [Accepted: 12/04/2022] [Indexed: 12/15/2022]
Abstract
Cross-education is the phenomenon where training of one limb can cause neuromuscular adaptations in the opposite untrained limb. This effect has been reported to be greater after eccentric (ECC) than concentric (CON) strength training; however, the underpinning neurophysiological mechanisms remain unclear. Thus, we compared responses to transcranial magnetic stimulation (TMS) in both motor cortices following single sessions of unilateral ECC and CON exercise of the elbow flexors. Fourteen healthy adults performed three sets of 10 ECC and CON right elbow flexor contractions at 75% of respective maximum on separate days. Elbow flexor maximal voluntary isometric contraction (MVIC) torques were measured before and after exercise, and responses to single- and paired-pulse TMS were recorded from the non-exercised left and exercised right biceps brachii. Pre-exercise and post-exercise responses for ECC and CON were compared by repeated measures analyses of variance (ANOVAs). MVIC torque of the exercised arm decreased (p < 0.01) after CON (-30 ± 14%) and ECC (-39 ± 13%) similarly. For the non-exercised left biceps brachii, resting motor threshold (RMT) decreased after CON only (-4.2 ± 3.9% of maximum stimulator output [MSO], p < 0.01), and intracortical facilitation (ICF) decreased (-15.2 ± 20.0%, p = 0.038) after ECC only. For the exercised right biceps, RMT increased after ECC (8.6 ± 6.2% MSO, p = 0.014) but not after CON (6.4 ± 8.1% MSO, p = 0.066). Thus, unilateral ECC and CON elbow flexor exercise modulated excitability differently for the non-exercised hemisphere. These findings suggest that responses after a single bout of exercise may not reflect longer term adaptations.
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Affiliation(s)
- Onno van der Groen
- Neurorehabilitation and Robotics Laboratory, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia.,Exercise Medicine Research Institute, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
| | - Christopher Latella
- School of Medical and Health Sciences, Centre for Human Performance, Edith Cowan University, Joondalup, Australia.,Neurophysiology Research Laboratory, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia
| | - Kazunori Nosaka
- Exercise Medicine Research Institute, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia.,School of Medical and Health Sciences, Centre for Human Performance, Edith Cowan University, Joondalup, Australia
| | - Dylan Edwards
- Neurorehabilitation and Robotics Laboratory, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia.,Exercise Medicine Research Institute, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia.,Moss Rehabilitation Research Institute, Elkins Park, Pennsylvania, USA
| | - Wei-Peng Teo
- Physical Education and Sports Science Academic Group, National Institute of Education, Nanyang Technological University, Singapore, Singapore
| | - Janet L Taylor
- School of Medical and Health Sciences, Centre for Human Performance, Edith Cowan University, Joondalup, Australia.,Neurophysiology Research Laboratory, School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia.,Neuroscience Research Australia, Randwick, Australia
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3
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Aybek S, Chan A. The borderland of multiple sclerosis and functional neurological disorder: A call for clinical research and vigilance. Eur J Neurol 2023; 30:3-8. [PMID: 36135345 DOI: 10.1111/ene.15568] [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: 02/20/2022] [Revised: 07/29/2022] [Accepted: 08/12/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND PURPOSE Functional neurological disorders (FNDs) have attracted much attention from the neurological medical community over the last decades as new developments in neurosciences have reduced stigma around these by showing brain network dysfunctions. An overlap with other neurological conditions such as multiple sclerosis (MS) is well known by clinicians but there is a lack of clinical and fundamental research in this field to better define diagnosis and therapeutic decisions, as well as a lack of deep understanding of the underlying pathophysiology. AIM We aimed to provide a critical commentary on the state of knowledge about the borderland between FNDs and MS. METHODS We based our commentary on a joint point of view between an FND specialist and an MS expert. RESULTS A brief review of the previous literature and relevant new studies covering the overlap between FNDs and MS is presented, along with suggestions for future research directions. CONCLUSION There are clear diagnostic criteria for both FNDs and MS and a strict application of these will help better diagnosis and prevent unnecessary treatment escalation in MS or absence of referral to multimodal therapy in FND. Better teaching of younger neurologists is needed as well as prospective research focusing on pathophysiology.
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Affiliation(s)
- Selma Aybek
- Psychosomatic Medicine Unit, Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Andrew Chan
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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4
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Wu YK, Harel NY, Wecht JM, Bloom OE. Effects of Remote Ischemic Conditioning on Hand Engagement in individuals with Spinal cord Injury (RICHES): protocol for a pilot crossover study. F1000Res 2022; 10:464. [PMID: 35342620 PMCID: PMC8924555 DOI: 10.12688/f1000research.52670.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/06/2022] [Indexed: 11/20/2022] Open
Abstract
Background: Most spinal cord injuries (SCI) are not full transections, indicating that residual nerve circuits are retained. Rehabilitation interventions have been shown to beneficially reorganize motor pathways in the brain, corticospinal tract, and at the spinal level. However, rehabilitation training require a large number of repetitions, and intervention effects may be absent or show transient retention. Therefore, the need remains for an effective approach to synergistically improve the amount and duration of neuroplasticity in combination with other interventions. Remote ischemic conditioning (RIC) demonstrates several potential advantages as a candidate for such an approach. Therefore, we propose a protocol to investigate RIC coupled with physical training to promote neuroplasticity in hand muscles. Methods: This will be a prospective randomized-order crossover trial to be performed in eight able-bodied participants and eight participants with chronic cervical SCI. Patients will participate in two experimental sessions consisting of either active or sham RIC preceding a bout of pinch movement exercise. Serial evaluations will be conducted at baseline, after RIC, immediately after pinch exercise, and follow up 15-minutes later. The primary outcome is the change in corticospinal excitability (primarily measured by the motor evoked potential of abductor pollicis brevis muscle). Secondary outcomes will include maximal volitional pinch force, and inflammatory biomarkers. To ensure safety, we will monitor tolerability and hemodynamic responses during RIC. Discussion: This protocol will be the first to test RIC in people with cervical SCI and to investigate whether RIC alters corticospinal excitability. By sharing the details of our protocol, we hope other interested researchers will seek to investigate similar approaches – depending on overlap with the current study and mutual sharing of participant-level data, this could increase the sample size, power, and generalizability of the analysis and results. Trial registration: ClinicalTrial.gov, ID: NCT03851302; Date of registration: February 22, 2019
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Affiliation(s)
- Yu-Kuang Wu
- Rehabilitation and Human Performance, Icahn School of Medicine at Mount Sinai, New York, NY, 10003, USA
- Bronx Veterans Medical Research Foundation, Bronx, NY, 10468, USA
| | - Noam Y. Harel
- Rehabilitation and Human Performance, Icahn School of Medicine at Mount Sinai, New York, NY, 10003, USA
- Bronx Veterans Medical Research Foundation, Bronx, NY, 10468, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10003, USA
| | - Jill M. Wecht
- Rehabilitation and Human Performance, Icahn School of Medicine at Mount Sinai, New York, NY, 10003, USA
- Bronx Veterans Medical Research Foundation, Bronx, NY, 10468, USA
| | - Ona E. Bloom
- Bronx Veterans Medical Research Foundation, Bronx, NY, 10468, USA
- The Feinstein Institute for Medical Research, Manhasset, NY, 11030, USA
- The Zucker School of Medicine at Hofstra Northwell, Hempstead, NY, 11549, USA
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5
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Abstract
Sleep homeostasis is a complex neurobiologic phenomenon involving a number of molecular pathways, neurotransmitter release, synaptic activity, and factors modulating neural networks. Sleep plasticity allows for homeostatic optimization of neural networks and the replay-based consolidation of specific circuits, especially important for cognition, behavior, and information processing. Furthermore, research is currently moving from an essentially brain-focused to a more comprehensive view involving other systems, such as the immune system, hormonal status, and metabolic pathways. When dysfunctional, these systems contribute to sleep loss and fragmentation as well as to sleep need. In this chapter, the implications of neural plasticity and sleep homeostasis for the diagnosis and treatment of some major sleep disorders, such as insomnia and sleep deprivation, obstructive sleep apnea syndrome, restless legs syndrome, REM sleep behavior disorder, and narcolepsy are discussed in detail with their therapeutical implications. This chapter highlights that sleep is necessary for the maintenance of an optimal brain function and is sensitive to both genetic background and environmental enrichment. Even in pathologic conditions, sleep acts as a resilient plastic state that consolidates prior information and prioritizes network activity for efficient brain functioning.
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6
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Wang B, Xiao S, Yu C, Zhou J, Fu W. Effects of Transcranial Direct Current Stimulation Combined With Physical Training on the Excitability of the Motor Cortex, Physical Performance, and Motor Learning: A Systematic Review. Front Neurosci 2021; 15:648354. [PMID: 33897361 PMCID: PMC8062775 DOI: 10.3389/fnins.2021.648354] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 03/08/2021] [Indexed: 01/28/2023] Open
Abstract
Purpose: This systematic review aims to examine the efficacy of transcranial direct current stimulation (tDCS) combined with physical training on the excitability of the motor cortex, physical performance, and motor learning. Methods: A systematic search was performed on PubMed, Web of Science, and EBSCO databases for relevant research published from inception to August 2020. Eligible studies included those that used a randomized controlled design and reported the effects of tDCS combined with physical training to improve motor-evoked potential (MEP), dynamic posture stability index (DPSI), reaction time, and error rate on participants without nervous system diseases. The risk of bias was assessed by the Cochrane risk of bias assessment tool. Results: Twenty-four of an initial yield of 768 studies met the eligibility criteria. The risk of bias was considered low. Results showed that anodal tDCS combined with physical training can significantly increase MEP amplitude, decrease DPSI, increase muscle strength, and decrease reaction time and error rate in motor learning tasks. Moreover, the gain effect is significantly greater than sham tDCS combined with physical training. Conclusion: tDCS combined with physical training can effectively improve the excitability of the motor cortex, physical performance, and motor learning. The reported results encourage further research to understand further the synergistic effects of tDCS combined with physical training.
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Affiliation(s)
- Baofeng Wang
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Songlin Xiao
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Changxiao Yu
- School of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Junhong Zhou
- The Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, United States.,Harvard Medical School, Boston, MA, United States
| | - Weijie Fu
- School of Kinesiology, Shanghai University of Sport, Shanghai, China.,Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai, China
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7
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State-of-the-art review: spinal and supraspinal responses to muscle potentiation in humans. Eur J Appl Physiol 2021; 121:1271-1282. [PMID: 33635383 DOI: 10.1007/s00421-021-04610-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 01/17/2021] [Indexed: 02/02/2023]
Abstract
Post-activation potentiation (PAP), described as a muscular phenomenon, refers to the enhancement of contractile properties following a voluntary or electrically stimulated short duration (< 10 s) high-intensity contraction. Mechanistic factors and subsequent effects on voluntary performance have been well documented. Associations between neural activation and PAP, however, are less understood and systematically have not been explored. Thus, the aim is to critically summarize the current understanding of PAP regarding the motor pathway from the corticospinal tract to spinal level factors including the H-reflex and motor unit activation. This review highlights aspects for further investigation by providing an integrative summary of the relationship between PAP and neural control. Contractile history affects neural control in subsequent contractions, (e.g. fatiguing tasks), however, by contrast acute contractile enhancement due to PAP in relation to neural responses are not well-studied. From the limited number of investigations, motor unit discharge rates are reduced subsequent to PAP and, although less consistently reported, generally H-reflexes are depressed. Additionally, corticomedullary evoked potentials are depressed and the cortical silent period is elongated. Thus, overall there is a depression of spinal and supraspinal responses following PAP. Although specific factors responsible and their pathways are unclear, this down-regulation may occur to conserve neural activation when muscle contraction is more responsive, and concurrently a strategy used to delay neuromuscular fatigue. Indeed, the co-existence of PAP and fatigue is not a novel concept, but the interactions between PAP and neural responses are not understood and likely are more than coincidental.
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8
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Dempsey LM, Kavanagh JJ. Muscarinic receptor blockade causes postcontraction enhancement in corticospinal excitability following maximal contractions. J Neurophysiol 2021; 125:1269-1278. [PMID: 33625939 DOI: 10.1152/jn.00673.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Although synaptic transmission in motor pathways can be regulated by neuromodulators, such as acetylcholine, few studies have examined how cholinergic activity affects cortical and spinal motor circuits following muscle contractions of varying intensities. This was a human, double-blinded, placebo-controlled, crossover study. Participants attended two sessions where they were administered either a placebo or 25 mg of promethazine. Electromyography of the abductor digiti minimi (ADM) was measured for all conditions. Motor evoked potentials (MEPs) were obtained via motor cortical transcranial magnetic stimulation (TMS), and F waves were obtained via ulnar nerve electrical stimulation. MEPs and F waves were examined: 1) when the muscle was at rest; 2) after the muscle had been active; and 3) after the muscle had been fatigued. MEPs were unaffected by muscarinic receptor blockade when measurements were recorded from resting muscle or following a 50% isometric maximal voluntary contraction (MVC). However, muscarinic receptor blockade increased MEP area following a 10-s MVC (P = 0.019) and following a fatiguing 60-s MVC (P = 0.040). F wave area and persistence were not affected by promethazine for any muscle contraction condition. Corticospinal excitability was influenced by cholinergic effects when voluntary drive to the muscle was high. Given that spinal motoneurone excitability remained unaffected, it is likely that cholinergic effects are influential within the motor cortex during strong muscle contractions. Future research should evaluate how cholinergic effects alter the relationship between subcortical structures and the motor cortex, as well as brainstem neuromodulatory pathways and spinal motoneurons.NEW & NOTEWORTHY The relationship between motor function and cholinergic circuitry in the central nervous system is complex. Although many studies have approached this issue at the cellular level, few studies have examined cholinergic mechanisms in humans performing muscle contractions. This study demonstrates that blockade of muscarinic acetylcholine receptors enhances motor evoked potentials (elicited with transcranial magnetic stimulation) following strong muscle contractions, but not weak muscle contractions.
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Affiliation(s)
- Lisa M Dempsey
- Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - Justin J Kavanagh
- Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
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9
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Dai W, Nakagawa K, Nakajima T, Kanosue K. Determinants of Neural Plastic Changes Induced by Motor Practice. Front Hum Neurosci 2021; 15:613867. [PMID: 33584230 PMCID: PMC7875877 DOI: 10.3389/fnhum.2021.613867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 01/04/2021] [Indexed: 11/29/2022] Open
Abstract
Short-term motor practice leads to plasticity in the primary motor cortex (M1). The purpose of this study is to investigate the factors that determine the increase in corticospinal tract (CST) excitability after motor practice, with special focus on two factors; “the level of muscle activity” and “the presence/absence of a goal of keeping the activity level constant.” Fifteen healthy subjects performed four types of rapid thumb adduction in separate sessions. In the “comfortable task” (C) and “forceful task” (F), the subjects adducted their thumb using comfortable and strong forces. In the “comfortable with a goal task” (CG) and “forceful with a goal task” (FG), subjects controlled the muscle activity at the same level as in the C and F, respectively, by adjusting the peak electromyographic amplitude within the target ranges. Paired associative stimulation (PAS), which combines peripheral nerve (median nerve) stimulation and transcranial magnetic stimulation (TMS), with an inter-stimulus interval of 25 ms (PAS25) was also done. Before and after the motor tasks and PAS25, TMS was applied to the M1. None of the four tasks showed any temporary changes in behavior, meaning no learning occurred. Motor-evoked potential (MEP) amplitude increased only after the FG and it exhibited a positive correlation with the MEP increase after PAS25, suggesting that FG and PAS25 share at least similar plasticity mechanisms in the M1. Resting motor threshold (RMT) decreased only after FG, suggesting that FG would also be associated with the membrane depolarization of M1 neurons. These results suggest task-dependent plasticity from the synergistic effect of forceful muscle activity and of setting a goal of keeping the activity level constant.
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Affiliation(s)
- Wen Dai
- Graduate School of Sport Sciences, Waseda University, Saitama, Japan
| | - Kento Nakagawa
- Faculty of Sport Sciences, Waseda University, Saitama, Japan
| | - Tsuyoshi Nakajima
- Department of Integrative Physiology, Kyorin University School of Medicine, Tokyo, Japan
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10
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Corticospinal excitability of untrained side depends on the type of motor task and degree of improvement in motor function. Brain Cogn 2021; 148:105691. [PMID: 33515865 DOI: 10.1016/j.bandc.2021.105691] [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: 07/11/2020] [Revised: 12/07/2020] [Accepted: 01/08/2021] [Indexed: 11/24/2022]
Abstract
Unimanual motor tasks change the corticospinal excitability of the trained and untrained side. However, whether the motor task type influences the modulation of the corticospinal excitability of the untrained side remains unclear. This study aimed to clarify the effects of motor tasks on the corticospinal excitability of the untrained side and the relationship between the excitability and motor function. In Experiment I, we measured the corticospinal excitability of the untrained side and motor function after 10 min of motor training in two conditions (gripping task and ball rotation task). The gripping task decreased the excitability. In contrast, excitability remained unchanged after the ball rotation task; further, the modulation of excitability and motor function showed a correlation. In Experiment II, we measured the corticospinal excitability of the untrained side and motor function after two sessions of the ball rotation task. The excitability increased, but motor function remained unchanged after the first session, whereas the excitability decreased to the level observed before training, and motor function improved after the second session. We suggest that the training condition modulates the corticospinal excitability of the untrained side and that this is related to the modulation of motor function.
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11
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Noreika V, Kamke MR, Canales-Johnson A, Chennu S, Bekinschtein TA, Mattingley JB. Alertness fluctuations when performing a task modulate cortical evoked responses to transcranial magnetic stimulation. Neuroimage 2020; 223:117305. [PMID: 32861789 PMCID: PMC7762840 DOI: 10.1016/j.neuroimage.2020.117305] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 07/31/2020] [Accepted: 08/21/2020] [Indexed: 12/21/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) has been widely used in human cognitive neuroscience to examine the causal role of distinct cortical areas in perceptual, cognitive and motor functions. However, it is widely acknowledged that the effects of focal cortical stimulation can vary substantially between participants and even from trial to trial within individuals. Recent work from resting state functional magnetic resonance imaging (fMRI) studies has suggested that spontaneous fluctuations in alertness over a testing session can modulate the neural dynamics of cortical processing, even when participants remain awake and responsive to the task at hand. Here we investigated the extent to which spontaneous fluctuations in alertness during wake-to-sleep transition can account for the variability in neurophysiological responses to TMS. We combined single-pulse TMS with neural recording via electroencephalography (EEG) to quantify changes in motor and cortical reactivity with fluctuating levels of alertness defined objectively on the basis of ongoing brain activity. We observed rapid, non-linear changes in TMS-evoked responses with decreasing levels of alertness, even while participants remained responsive in the behavioural task. Specifically, we found that the amplitude of motor evoked potentials peaked during periods of EEG flattening, whereas TMS-evoked potentials increased and remained stable during EEG flattening and the subsequent occurrence of theta ripples that indicate the onset of NREM stage 1 sleep. Our findings suggest a rapid and complex reorganization of active neural networks in response to spontaneous fluctuations of alertness over relatively short periods of behavioural testing during wake-to-sleep transition.
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Affiliation(s)
- Valdas Noreika
- Queensland Brain Institute, University of Queensland, St Lucia, QLD 4072, Australia; Cambridge Consciousness and Cognition Lab, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom; Department of Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom.
| | - Marc R Kamke
- Queensland Brain Institute, University of Queensland, St Lucia, QLD 4072, Australia
| | - Andrés Canales-Johnson
- Cambridge Consciousness and Cognition Lab, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom; Vicerrectoría de Investigación y Posgrado, Universidad Católica del Maule, Talca, Chile
| | - Srivas Chennu
- School of Computing, University of Kent, Medway, United Kingdom; Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Tristan A Bekinschtein
- Cambridge Consciousness and Cognition Lab, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom
| | - Jason B Mattingley
- Queensland Brain Institute, University of Queensland, St Lucia, QLD 4072, Australia; School of Psychology, University of Queensland, St Lucia, QLD 4072, Australia; Canadian Institute for Advanced Research (CIFAR), Canada
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12
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Hogan PS, Chen SX, Teh WW, Chib VS. Neural mechanisms underlying the effects of physical fatigue on effort-based choice. Nat Commun 2020; 11:4026. [PMID: 32788604 PMCID: PMC7424567 DOI: 10.1038/s41467-020-17855-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 07/20/2020] [Indexed: 11/26/2022] Open
Abstract
Physical fatigue crucially influences our decisions to partake in effortful action. However, there is a limited understanding of how fatigue impacts effort-based decision-making at the level of brain and behavior. We use functional magnetic resonance imaging to record markers of brain activity while human participants engage in uncertain choices for prospective physical effort, before and after bouts of exertion. Using computational modeling of choice behavior we find that fatiguing exertions cause participants to increase their subjective cost of effort, compared to a baseline/rested state. We describe a mechanism by which signals related to motor cortical state in premotor cortex influence effort value computations, instantiated by insula, thereby increasing an individual's subjective valuation of prospective physical effort while fatigued. Our findings provide a neurobiological account of how information about bodily state modulates decisions to engage in physical activity.
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Affiliation(s)
- Patrick S Hogan
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Steven X Chen
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Wen Wen Teh
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Vikram S Chib
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD, 21205, USA.
- Kennedy Krieger Institute, 707 North Broadway, Baltimore, MD, 21205, USA.
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13
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Forman DA, Forman GN, Murphy BA, Holmes MWR. Sustained Isometric Wrist Flexion and Extension Maximal Voluntary Contractions on Corticospinal Excitability to Forearm Muscles during Low-Intensity Hand-Gripping. Brain Sci 2020; 10:E445. [PMID: 32668568 PMCID: PMC7408559 DOI: 10.3390/brainsci10070445] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/06/2020] [Accepted: 07/07/2020] [Indexed: 02/02/2023] Open
Abstract
The wrist extensors demonstrate an earlier fatigue onset than the wrist flexors. However, it is currently unclear whether fatigue induces unique changes in muscle activity or corticospinal excitability between these muscle groups. The purpose of this study was to examine how sustained isometric wrist extension/flexion maximal voluntary contractions (MVCs) influence muscle activity and corticospinal excitability of the forearm. Corticospinal excitability to three wrist flexors and three wrist extensors were measured using motor evoked potentials (MEPs) elicited via transcranial magnetic stimulation. Responses were elicited while participants exerted 10% of their maximal handgrip force, before and after a sustained wrist flexion or extension MVC (performed on separate sessions). Post-fatigue measures were collected up to 10-min post-fatigue. Immediately post-fatigue, extensor muscle activity was significantly greater following the wrist flexion fatigue session, although corticospinal excitability (normalized to muscle activity) was greater on the wrist extension day. Responses were largely unchanged in the wrist flexors. However, for the flexor carpi ulnaris, normalized MEP amplitudes were significantly larger following wrist extension fatigue. These findings demonstrate that sustained isometric flexion/extension MVCs result in a complex reorganization of forearm muscle recruitment strategies during hand-gripping. Based on these findings, previously observed corticospinal behaviour following fatigue may not apply when the fatiguing task and measurement task are different.
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Affiliation(s)
- Davis A. Forman
- Faculty of Science, Ontario Tech University, Oshawa, ON L1G 0C5, Canada;
| | - Garrick N. Forman
- Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada;
| | - Bernadette A. Murphy
- Faculty of Health Sciences, Ontario Tech University, Oshawa, ON L1G 0C5, Canada;
| | - Michael W. R. Holmes
- Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada;
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14
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Nardone R, Sebastianelli L, Versace V, Brigo F, Golaszewski S, Pucks-Faes E, Saltuari L, Trinka E. Contribution of transcranial magnetic stimulation in restless legs syndrome: pathophysiological insights and therapeutical approaches. Sleep Med 2020; 71:124-134. [PMID: 32088150 DOI: 10.1016/j.sleep.2019.12.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 12/10/2019] [Accepted: 12/11/2019] [Indexed: 01/06/2023]
Abstract
Transcranial magnetic stimulation (TMS) may offer a reliable means to characterize significant pathophysiologic and neurochemical aspects of restless legs syndrome (RLS). Namely, TMS has revealed specific patterns of changes in cortical excitability and plasticity, in particular dysfunctional inhibitory mechanisms and sensorimotor integration, which are thought to be part of the pathophysiological mechanisms of RLS rather than reflect a non-specific consequence of sleep architecture alteration. If delivered repetitively, TMS is able to transiently modulate the neural activity of the stimulated and connected areas. Some studies have begun to therapeutically use repetitive TMS (rTMS) to improve sensory and motor disturbances in RLS. High-frequency rTMS applied over the primary motor cortex or the supplementary motor cortex, as well as low-frequency rTMS over the primary somatosensory cortex, seem to have transient beneficial effects. However, further studies with larger patient samples, repeated sessions, an optimized rTMS setup, and clinical follow-up are needed in order to corroborate preliminary results. Thus, we performed a systematic search of all the studies that have used TMS and rTMS techniques in patients with RLS.
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Affiliation(s)
- Raffaele Nardone
- Department of Neurology, Franz Tappeiner Hospital, Merano, Italy; Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Spinal Cord Injury and Tissue Regeneration Center, Salzburg, Austria; Karl Landsteiner Institut für Neurorehabilitation und Raumfahrtneurologie, Salzburg, Austria.
| | - Luca Sebastianelli
- Department of Neurorehabilitation, Hospital of Vipiteno, Vipiteno, Italy; Research Unit for Neurorehabilitation South Tyrol, Bolzano, Italy
| | - Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno, Vipiteno, Italy; Research Unit for Neurorehabilitation South Tyrol, Bolzano, Italy
| | - Francesco Brigo
- Department of Neurology, Franz Tappeiner Hospital, Merano, Italy; Department of Neuroscience, Biomedicine and Movement Science, University of Verona, Italy
| | - Stefan Golaszewski
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Karl Landsteiner Institut für Neurorehabilitation und Raumfahrtneurologie, Salzburg, Austria
| | | | - Leopold Saltuari
- Department of Neurorehabilitation, Hospital of Vipiteno, Vipiteno, Italy; Research Unit for Neurorehabilitation South Tyrol, Bolzano, Italy; Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Eugen Trinka
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Centre for Cognitive Neurosciences Salzburg, Salzburg, Austria; University for Medical Informatics and Health Technology, UMIT, Hall in Tirol, Austria
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15
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Aboodarda SJ, Zhang CXY, Sharara R, Cline M, Millet GY. Exercise-Induced Fatigue in One Leg Does Not Impair the Neuromuscular Performance in the Contralateral Leg but Improves the Excitability of the Ipsilateral Corticospinal Pathway. Brain Sci 2019; 9:brainsci9100250. [PMID: 31557879 PMCID: PMC6827080 DOI: 10.3390/brainsci9100250] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 09/17/2019] [Accepted: 09/20/2019] [Indexed: 11/16/2022] Open
Abstract
To investigate the influence of pre-induced fatigue in one leg on neuromuscular performance and corticospinal responses of the contralateral homologous muscles, three experiments were conducted with different exercise protocols; A (n = 12): a 60 s rest vs. time-matched sustained left leg knee extension maximum voluntary contraction (MVC), B (n = 12): a 60 s rest vs. time-matched left leg MVC immediately followed by 60 s right leg MVC, and C (n = 9): a similar protocol to experiment B, but with blood flow occluded in the left leg while the right leg was performing the 60 s MVC. The neuromuscular assessment included 5 s knee extensions at 100%, 75%, and 50% of MVC. At each force level, transcranial magnetic and peripheral nerve stimuli were elicited to investigate the influence of different protocols on the right (tested) knee extensors’ maximal force output, voluntary activation, corticospinal excitability, and inhibition. The pre-induced fatigue in the left leg did not alter the performance nor the neuromuscular responses recorded from the right leg in the three experiments (all p > 0.3). However, enhanced corticospinal pathway excitability was evident in the tested knee extensors (p = 0.002). These results suggest that the pre-induced fatigue and muscle ischemia in one leg did not compromise the central and peripheral components of the neuromuscular function in the tested contralateral leg.
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Affiliation(s)
| | - Cindy Xin Yu Zhang
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada.
| | - Ruva Sharara
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada.
| | - Madeleine Cline
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada.
| | - Guillaume Y Millet
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada.
- Inter-University Laboratory of Human Movement Biology, University of Lyon, UJM-Saint-Etienne, EA 7424, F-42023 Saint-Etienne, France.
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16
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Kjeldsen SS, Næss-Schmidt ET, Hansen GM, Nielsen JF, Stubbs PW. Neuromuscular effects of dorsiflexor training with and without blood flow restriction. Heliyon 2019; 5:e02341. [PMID: 31467996 PMCID: PMC6710534 DOI: 10.1016/j.heliyon.2019.e02341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 03/26/2019] [Accepted: 08/15/2019] [Indexed: 10/27/2022] Open
Abstract
Blood flow restriction training (BFRT) has been proposed for elderly and clinical populations with weakness. Before being used in these populations it is important to understand the neurological effects of, and subject perceptions to, BFRT. Seventeen healthy subjects were recruited and performed 2 experimental sessions, BFRT and training without blood flow restriction (TR-only), on separate days. Four sets of concentric/eccentric dorsiflexion contractions against theraband resistance were performed. Surface electromyography of the tibialis anterior was recorded during exercise and for the electrophysiological measures. At baseline, immediately-post, 10-min-post and 20-min-post exercise, motor evoked potentials (MEPs) from single pulse transcranial magnetic stimulation (TMS), paired-pulse TMS with interstimulus intervals of 2-ms (SICI) and 15-ms (ICF), and the M-max amplitude were recorded in the resting TA. Following training, subjects provided a numerical rating of the levels of pain, discomfort, fatigue, focus and difficulty during training. Muscle activation was higher in the last 20 contractions during BFRT compared to TR. There was no difference (time × condition interaction) between BFRT and TR for single-pulse MEP, SICI, ICF or M-max amplitude. There was a significant main effect of timepoint for single-pulse MEP and M-max amplitudes with both significantly reduced for 20-min-post exercise. No reductions were observed for SICI and ICF amplitudes. Taken together, BFRT and TR-only were only different during exercise and both regimes induced similar significant reductions in M-Max and MEP-amplitude post-training. Due to the lack of changes in SICI and ICF, it is unlikely that changes occurred in cortical sites related to these pathways. The increased surface electromyography activity in the last 20 contractions, indicate that the training regimes are different and that BFRT possibly induces more fatigue than TR. As such, BFRT could be used as an adjunct to conventional training. However, as subjects perceived BFRT as more painful, difficult and uncomfortable than TR-only, people should be selected carefully to undertake BFRT.
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Affiliation(s)
- Simon Svanborg Kjeldsen
- Research Department, Hammel Neurorehabilitation and Research Center, Aarhus University, Hammel, Denmark
| | | | - Gunhild Mo Hansen
- Research Department, Hammel Neurorehabilitation and Research Center, Aarhus University, Hammel, Denmark
| | - Jørgen Feldbæk Nielsen
- Research Department, Hammel Neurorehabilitation and Research Center, Aarhus University, Hammel, Denmark
| | - Peter William Stubbs
- Research Department, Hammel Neurorehabilitation and Research Center, Aarhus University, Hammel, Denmark.,University of Technology Sydney, Graduate School of Health, Discipline of Physiotherapy, Sydney, Australia
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17
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Tsuiki S, Sasaki R, Pham MV, Miyaguchi S, Kojima S, Saito K, Inukai Y, Otsuru N, Onishi H. Repetitive Passive Movement Modulates Corticospinal Excitability: Effect of Movement and Rest Cycles and Subject Attention. Front Behav Neurosci 2019; 13:38. [PMID: 30881295 PMCID: PMC6405431 DOI: 10.3389/fnbeh.2019.00038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 02/14/2019] [Indexed: 11/13/2022] Open
Abstract
Repetitive passive movement (PM) affects corticospinal excitability; however, it is unknown whether a duty cycle which repeats movement and rest, or subjects’ conscious attention to movements, affects corticospinal excitability. We aimed to clarify the effect of the presence or absence of a duty cycle and subjects’ attention on corticospinal excitability. Three experiments were conducted. In Experiment 1, PM of the right index finger was performed for 10 min. Three conditions were used: (1) continuous PM (cPM) at a rate of 40°/s; (2) intermittent PM (iPM) with a duty cycle at 40°/s; and (3) iPM at 100°/s. In conditions 1 and 3, motor evoked potential (MEP) amplitude was significantly reduced. In Experiment 2, PM was performed for 30 min: condition 1 comprised cPM at a rate of 40°/s and Condition 2 comprised iPM at 40°/s. MEP amplitude significantly decreased in both conditions. In Experiment 3, PM was performed for 10 min: condition 1 comprised paying attention to the moving finger during iPM and Condition 2 was similar to Condition 1 but while counting images on a monitor without looking at the movement finger, and Condition 3 comprised counting images on a monitor without performing PM. MEP amplitude significantly increased only under Condition 1. Thus, afferent input from movements above a certain threshold may affect corticospinal excitability reduction. Furthermore, corticospinal excitability increases when paying attention to passive finger movement.
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Affiliation(s)
- Shota Tsuiki
- Rehabilitation Center of Shiobara Hot Spring Hospital, Tochigi Medical Association, Tochigi, Japan.,Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Ryoki Sasaki
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Manh Van Pham
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Shota Miyaguchi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Sho Kojima
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Kei Saito
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Yasuto Inukai
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Naofumi Otsuru
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Hideaki Onishi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
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18
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Effects of taurine acute intake on cortical excitability and post-exercise facilitation: A TMS study. Behav Brain Res 2019; 359:719-722. [PMID: 30248365 DOI: 10.1016/j.bbr.2018.09.014] [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: 07/25/2018] [Revised: 09/18/2018] [Accepted: 09/18/2018] [Indexed: 11/22/2022]
Abstract
Taurine (TAU) is one of the most abundant amino acids in the brain. It has many important physiological functions. The effects of TAU supplementation on brain function need to be further characterized in humans. The purpose of this study was to investigate whether a single dose of Taurine (TAU) intake would modulate corticospinal excitability and post-exercise facilitation (PEF) of the motor evoked potentials (MEP).
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19
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Onishi H. Cortical excitability following passive movement. Phys Ther Res 2018; 21:23-32. [PMID: 30697506 DOI: 10.1298/ptr.r0001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 09/12/2018] [Indexed: 12/15/2022]
Abstract
In brain injury rehabilitation, passive movement exercises are frequently used to maintain or improve mobility and range of motion. They can also induce beneficial and sustained neuroplastic changes. Neuroimaging studies have revealed that passive movements without motor commands activate not only the primary somatosensory cortex but also the primary motor cortex, supplementary motor area, and posterior parietal cortex as well as the secondary somatosensory cortex (S2) in healthy subjects. Repetitive passive movement has also been reported to induce increases or decreases in cortical excitability. In this review, we focused on the following: cortical activity following passive movement; cortical excitability during passive movement; and changes in cortical excitability after repetitive passive movement.
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Affiliation(s)
- Hideaki Onishi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare.,Department of Physical Therapy, Niigata University of Health and Welfare
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20
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Ishikawa N, Miyao R, Tsuiki S, Sasaki R, Miyaguchi S, Onishi H. Corticospinal excitability following repetitive voluntary movement. J Clin Neurosci 2018; 57:93-98. [DOI: 10.1016/j.jocn.2018.08.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 08/12/2018] [Indexed: 10/28/2022]
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21
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Goodall S, Howatson G, Thomas K. Modulation of specific inhibitory networks in fatigued locomotor muscles of healthy males. Exp Brain Res 2017; 236:463-473. [PMID: 29214392 PMCID: PMC5809538 DOI: 10.1007/s00221-017-5142-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 12/01/2017] [Indexed: 12/12/2022]
Abstract
Reduced maximal force capability of skeletal muscle, as a consequence of exercise, can be due to peripheral or central fatigue mechanisms. In upper-limb muscles, neuromuscular fatigue is concurrent with reduced corticospinal excitability and increased inhibition (lengthened corticospinal silent period [CSP]; reduced short-interval intracortical inhibition [SICI] ratio). However, it is unclear whether these adjustments occur in response to fatiguing exercise of locomotor muscles. This study examined the effect of fatiguing, maximal, knee-extensor exercise on motor cortical excitability and inhibition. Thirteen males performed three 30-s maximal, isometric contractions with the dominant knee-extensors (MVC1, MVC2 and MVC3), separated by 60 s. At the end of, and between each MVC, neuromuscular fatigue, corticospinal excitability, CSP and SICI were assessed with supramaximal stimulation of the femoral nerve, and motor cortical stimulation, respectively. Repeated MVCs caused progressive reductions in MVC (- 10, - 24 and - 29%, respectively, P ≤ 0.01), along with significant peripheral (reductions in potentiated twitch of - 23, -53 and - 60%, respectively, P < 0.001) and central (reductions in VA of - 10% and - 13% post-MVC2 and 3, respectively, P ≤ 0.01) fatigue. Following MVC1 corticospinal excitability was reduced, and remained depressed thereafter. CSP increased in duration and remained longer throughout the protocol; whereas, no change in SICI was observed. Repeated, sustained, maximal contractions of the knee-extensors elicited substantial peripheral and central fatigue that was accompanied by a concomitant reduction in corticospinal excitability. However, divergent responses exist between inhibitory networks within the motor cortex, the activity of inhibitory networks mediated by GABAB are increased, whereas those mediated by GABAA are not.
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Affiliation(s)
- Stuart Goodall
- Department of Sport, Exercise, and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, NE1 8ST, UK.
| | - Glyn Howatson
- Department of Sport, Exercise, and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, NE1 8ST, UK
- Water Research Group, School of Environmental Sciences and Development, Northwest University, Potchefstroom, South Africa
| | - Kevin Thomas
- Department of Sport, Exercise, and Rehabilitation, Faculty of Health and Life Sciences, Northumbria University, Newcastle-upon-Tyne, NE1 8ST, UK
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22
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Caffeinated energy drink intake modulates motor circuits at rest, before and after a movement. Physiol Behav 2017; 179:361-368. [DOI: 10.1016/j.physbeh.2017.07.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 07/03/2017] [Accepted: 07/07/2017] [Indexed: 11/20/2022]
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23
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Miyaguchi S, Kojima S, Sasaki R, Kotan S, Kirimoto H, Tamaki H, Onishi H. Decrease in short-latency afferent inhibition during corticomotor postexercise depression following repetitive finger movement. Brain Behav 2017; 7:e00744. [PMID: 28729946 PMCID: PMC5516614 DOI: 10.1002/brb3.744] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 04/25/2017] [Accepted: 04/30/2017] [Indexed: 11/26/2022] Open
Abstract
INTRODUCTION This study aimed to clarify cortical circuit mechanisms contributing to corticomotor excitability during postexercise depression (PED) following repetitive nonfatiguing movement. We investigated changes in short-latency afferent inhibition (SAI) and short-interval intracortical inhibition (SICI) by paired-pulse transcranial magnetic stimulation (TMS) during PED. METHODS A total of 16 healthy subjects performed repetitive abduction movements of the right index finger at 2.0 Hz for 6 min at 10% maximum voluntary contraction. We measured SAI evoked by pairing ulnar nerve stimulation with TMS (interstimulus interval, 22 ms) before and during PED (n = 10, experiment 1). We also measured SICI evoked by paired TMS (interstimulus interval, 2 ms) at 80% resting motor threshold (n = 10, experiment 2), and at 80% active motor threshold (n = 8, experiment 3) before and during PED. RESULTS Single motor evoked potential amplitude significantly decreased 1-2 min after the movement task in all experiments, indicating reliable PED induction. In experiment 1, SAI significantly decreased (disinhibited) 1-2 min during PED, whereas in experiments 2 and 3, SICI showed no significant change during PED. CONCLUSION This study suggests that cholinergic inhibitory circuit activity decreases during PED following repetitive nonfatiguing movement, whereas GABAA circuit activity remains stable.
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Affiliation(s)
- Shota Miyaguchi
- Institute for Human Movement and Medical Sciences Niigata University of Health and Welfare Niigata Japan
| | - Sho Kojima
- Institute for Human Movement and Medical Sciences Niigata University of Health and Welfare Niigata Japan
| | - Ryoki Sasaki
- Institute for Human Movement and Medical Sciences Niigata University of Health and Welfare Niigata Japan
| | - Shinichi Kotan
- Institute for Human Movement and Medical Sciences Niigata University of Health and Welfare Niigata Japan
| | - Hikari Kirimoto
- Institute for Human Movement and Medical Sciences Niigata University of Health and Welfare Niigata Japan
| | - Hiroyuki Tamaki
- Institute for Human Movement and Medical Sciences Niigata University of Health and Welfare Niigata Japan
| | - Hideaki Onishi
- Institute for Human Movement and Medical Sciences Niigata University of Health and Welfare Niigata Japan
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24
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Suruagy I, Baltar A, Gomes LP, Berenguer M, Dornelas A, Monte-Silva K. Intensity-dependent effects of cycling exercise on corticospinal excitability in healthy humans: a pilot study. MOTRIZ: REVISTA DE EDUCACAO FISICA 2017. [DOI: 10.1590/s1980-6574201700020002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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25
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Collins BW, Gale LH, Buckle NCM, Button DC. Corticospinal excitability to the biceps brachii and its relationship to postactivation potentiation of the elbow flexors. Physiol Rep 2017; 5:5/8/e13265. [PMID: 28455452 PMCID: PMC5408290 DOI: 10.14814/phy2.13265] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 03/30/2017] [Accepted: 04/05/2017] [Indexed: 11/24/2022] Open
Abstract
We examined the effects of a submaximal voluntary elbow flexor contraction protocol on measures of corticospinal excitability and postactivation potentiation of evoked muscle forces and if these measures were state‐dependent (rest vs. voluntary muscle contraction). Participants completed four experimental sessions where they rested or performed a 5% maximum voluntary contraction (MVC) of the elbow flexors prior to, immediately, and 5 min following a submaximal contraction protocol. During rest or 5% MVC, transcranial magnetic stimulation, transmastoid electrical stimulation, electrical stimulation of biceps brachii motor point and Erb's point were elicited to induce motor‐evoked potentials (MEPs), cervicomedullary MEPs (CMEPs), potentiated twitch (PT) force, and maximal muscle compound action potential (Mmax), respectively prior to, immediately, and 5 min postcontraction protocol. MEP amplitudes increased (215 and 165%Mmax, P ≤ 0.03) only at 1 and 6s postcontraction protocol, respectively during rest but not 5% MVC. CMEP amplitudes decreased during rest and 5% MVC (range:21–58%Mmax, P ≤ 0.04) for up to 81 sec postcontraction protocol. Peak twitch force increased immediately postcontraction protocol and remained elevated for 90 sec (range:122–147% increase, P < 0.05). There was a significant positive correlation between MEP and PT force during rest (r = 0.88, P = 0.01) and a negative correlation between CMEP and PT force during rest (r = −0.85, P < 0.02 and 5% MVC (r = −0.96, P < 0.01) immediately postcontraction protocol. In conclusion, the change in corticospinal and spinal excitability was state‐ and time‐dependent whereas spinal excitability and postactivation potentiation were time‐dependent following the contraction protocol. Changes in corticospinal excitability and postactivation potentiation correlated and were also state‐dependent.
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Affiliation(s)
- Brandon W Collins
- Human Neurophysiology Laboratory, School of Human Kinetics and Recreation, Newfoundland and Labrador Canada
| | - Laura H Gale
- Human Neurophysiology Laboratory, School of Human Kinetics and Recreation, Newfoundland and Labrador Canada
| | - Natasha C M Buckle
- Human Neurophysiology Laboratory, School of Human Kinetics and Recreation, Newfoundland and Labrador Canada
| | - Duane C Button
- Human Neurophysiology Laboratory, School of Human Kinetics and Recreation, Newfoundland and Labrador Canada .,BioMedical Sciences, Faculty of Medicine Memorial University St. John's, Newfoundland and Labrador, Canada
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26
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Lanza G, Bachmann CG, Ghorayeb I, Wang Y, Ferri R, Paulus W. Central and peripheral nervous system excitability in restless legs syndrome. Sleep Med 2017; 31:49-60. [PMID: 27745789 DOI: 10.1016/j.sleep.2016.05.010] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 05/24/2016] [Accepted: 05/30/2016] [Indexed: 02/07/2023]
Abstract
Neurophysiological techniques have been applied in restless legs syndrome (RLS) to obtain direct and indirect measures of central and peripheral nervous system excitability, as well as to probe different neurotransmission pathways. Data converge on the hypothesis that, from a pure electrophysiological perspective, RLS should be regarded as a complex sensorimotor disorder in which cortical, subcortical, spinal cord, and peripheral nerve generators are all involved in a network disorder, resulting in an enhanced excitability and/or decreased inhibition. Although the spinal component may have dominated in neurophysiological assessment, possibly because of better accessibility compared to the brainstem or cerebral components of a hypothetical dysfunction of the diencephalic A11 area, multiple mechanisms, such as reduced central inhibition and abnormal peripheral nerve function, contribute to the pathogenesis of RLS similarly to some chronic pain conditions. Dopamine transmission dysfunction, either primary or triggered by low iron and ferritin concentrations, may also bridge the gap between RLS and chronic pain entities. Further support of disturbed central and peripheral excitability in RLS is provided by the effectiveness of nonpharmacological tools, such as repetitive transcranial magnetic stimulation and transcutaneous spinal direct current stimulation, in transiently modulating neural excitability, thereby extending the therapeutic repertoire. Understanding the complex interaction of central and peripheral neuronal circuits in generating the symptoms of RLS is mandatory for a better refinement of its therapeutic support.
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Affiliation(s)
- Giuseppe Lanza
- Sleep Research Center, I.R.C.C.S. "Oasi Maria SS.", Troina, Italy.
| | | | - Imad Ghorayeb
- Department of Clinical Neurophysiology, CHU de Bordeaux, Bordeaux, France; CNRS, INCIA, CNRS UMR 5287, Université de Bordeaux, Bordeaux, France
| | - Yuping Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Raffale Ferri
- Sleep Research Center, I.R.C.C.S. "Oasi Maria SS.", Troina, Italy
| | - Walter Paulus
- Department of Clinical Neurophysiology, University Medical Center, Georg August University Göttingen, Göttingen, Germany
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27
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Concerto C, Babayev J, Mahmoud R, Rafiq B, Chusid E, Aguglia E, Coira D, Battaglia F. Modulation of prefrontal cortex with anodal tDCS prevents post-exercise facilitation interference during dual task. Somatosens Mot Res 2017; 34:80-84. [DOI: 10.1080/08990220.2017.1292238] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Carmen Concerto
- Department of Interprofessional Health Sciences & Health Administration, Seton Hall University, South Orange, NJ, USA
| | - Jacqueline Babayev
- Pre-clinical Sciences, New York College of Podiatric Medicine, New York, USA
| | - Rowan Mahmoud
- Pre-clinical Sciences, New York College of Podiatric Medicine, New York, USA
| | - Basil Rafiq
- Pre-clinical Sciences, New York College of Podiatric Medicine, New York, USA
| | - Eileen Chusid
- Pre-clinical Sciences, New York College of Podiatric Medicine, New York, USA
| | - Eugenio Aguglia
- Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Diego Coira
- Department of Psychiatry and Behavioral Medicine, Hackensack University Medical Center, Hackensack, NJ, USA
| | - Fortunato Battaglia
- Department of Interprofessional Health Sciences & Health Administration, Seton Hall University, South Orange, NJ, USA
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28
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Corticospinal excitability changes following blood flow restriction training of the tibialis anterior: a preliminary study. Heliyon 2017; 3:e00217. [PMID: 28127587 PMCID: PMC5241574 DOI: 10.1016/j.heliyon.2016.e00217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 12/16/2016] [Indexed: 11/22/2022] Open
Abstract
AIM To examine the neural excitability of projections to the tibialis anterior (TA) following blood flow restriction training (BFRT). This is the first study to examine the TA following BFRT. METHODS Ten subjects performed each experiment. Experiment one consisted of BFRT at 130 mmHg (BFRT-low). Experiment two consisted of BFRT at 200 mmHg (BFRT-high), training (TR-only) and blood flow restriction at 200 mmHg (BFR-only) performed on separate days. Blood flow restriction was applied to the thigh and training consisted of rapid dorsiflexion contractions against gravity every 10 s for 15-min. The motor evoked potential (MEP) peak-to-peak amplitudes were recorded pre-intervention and 1-, 10-, 20- and 30-min post-intervention and expressed relative to the maximal peak-to-peak M-wave at each time-point. RESULTS Experiment one revealed no difference in MEP amplitudes for BFRT-low over time (P = 0.09). Experiment two revealed a significant effect of time (P < 0.001), with 1-min post-intervention MEP amplitudes significantly facilitated compared to pre-intervention, but no effect of intervention (P = 0.79) or intervention*time interaction (P = 0.25). Post-hoc power calculations were performed for the intervention*time interaction. DISCUSSION AND CONCLUSIONS Corticospinal excitability of projections to the TA did not change following BFRT-low and corticospinal excitability changes between BFRT-high, BFR-only and TR-only interventions were not different over time. In experiment two, there was a significant main effect of time 1-min post-intervention which was mainly due to the BFRT-high intervention. Post-hoc power calculations revealed that 15 subjects were required for a significant interaction effect 80% of the time however, as the changes in corticospinal excitability were not prolonged, a new dataset of ≥ 15 subjects was not acquired.
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Knee extensors neuromuscular fatigue changes the corticospinal pathway excitability in biceps brachii muscle. Neuroscience 2016; 340:477-486. [PMID: 27826108 DOI: 10.1016/j.neuroscience.2016.10.065] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/09/2016] [Accepted: 10/30/2016] [Indexed: 01/07/2023]
Abstract
Equivocal evidence indicates that high-intensity muscle contractions can affect the corticospinal responses in muscles not directly involved in the task. In the present study, the responsiveness of corticomotor pathway innervating non-dominant biceps brachii was measured in eleven healthy participants before and after: (i) two 100-s isometric unilateral knee extension maximal voluntary contractions (MVCs) on dominant leg (FATIGUE) and (ii) rest (CONTROL). Transcranial magnetic stimulation, transmastoid electrical and brachial plexus electrical stimulation were used to evoke motor evoked potential (MEP), cervicomedullary motor evoked potential (CMEP) and compound muscle action potential (Mmax) in biceps brachii muscle. The three stimuli were elicited at 2, 3.5 and 5s while participants were performing 6-s elbow flexion contractions at 100, 50, and 5% of MVC interspersed with 10-s rest. The results demonstrated opposing behaviors of MEP responses at 100% (23% higher, p=0.08) and 5% MVC (34% lower, p=0.019) following FATIGUE compared to CONTROL. Similarly, MEP·CMEP-1 ratio changes indicated that the supraspinal motor response was significantly higher during 100% (42%, p=0.027) but lower during 5% MVC (28%, p=0.009) following FATIGUE. Yet, the elbow flexor MVC force did not exhibit any difference between FATIGUE and CONTROL conditions. These results suggest that the upper limb muscles' corticomotor pathway responsiveness recorded during voluntary contractions were modulated by lower limbs fatiguing contractions and this modulation depends on the force produced during testing, i.e. level of central motor drive. However, these changes have little effect on upper limb muscle maximal performance.
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Concerto C, Amer B, Abagyan A, Cao Y, Infortuna C, Chusid E, Coira D, Battaglia F. Influence of dual-task on postexercise facilitation: a transcranial magnetic stimulation study. J Exerc Rehabil 2016; 12:171-5. [PMID: 27419111 PMCID: PMC4934960 DOI: 10.12965/jer.1632628.314] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 06/03/2016] [Indexed: 11/22/2022] Open
Abstract
In this study we investigated the effect of a dual task (DT) comprised of a nonfatiguing leg and foot extension coupled with a calculation task on postexercise facilitation (PEF) of motor evoked potentials (MEPs) tested by using transcranial magnetic stimulation (TMS). Twelve right-handed healthy subjects participated in the study. They were required to perform a motor task, a cognitive task and a DT. The motor task consisted of extending the right leg and foot for 30 sec at 20% of the maximal voluntary contraction. The cognitive task consisted of a 30-sec backward calculation. In the DT condition, motor and cognitive tasks were performed concurrently. Resting motor threshold and 10 MEPs were collected before and immediately after each task. TMS was delivered to the motor hot spot of the right vastus lateralis and tibialis anterior (TA) muscles. Results showed that exercise induced a significant PEF in both VL and TA muscles while calculation was not associated with significant PEF. Furthermore, DT was associated with lack of significant PEF in both muscles (VL, 116.1%±9.6%; TA, 115.7%±9%). Our data indicates DT interference on corticospinal excitability after a nonfatiguing exercise. Our experimental paradigm may be used to address postexercise motor cortex plastic adaptations induced by motor and cognitive tasks of different complexity in sport, aging and neuropsychiatric diseases.
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Affiliation(s)
- Carmen Concerto
- Department of Interprofessional Health Sciences & Health Administration, School of Health and Medical Sciences, Seton Hall University, South Orange, NJ, USA
| | - Bahaa Amer
- Department of Pre-clinical Sciences, New York College of Podiatric Medicine, New York, NY, USA
| | - Anaida Abagyan
- Department of Pre-clinical Sciences, New York College of Podiatric Medicine, New York, NY, USA
| | - Yisheng Cao
- Department of Pre-clinical Sciences, New York College of Podiatric Medicine, New York, NY, USA
| | - Carmenrita Infortuna
- Department of Pre-clinical Sciences, New York College of Podiatric Medicine, New York, NY, USA
| | - Eileen Chusid
- Department of Pre-clinical Sciences, New York College of Podiatric Medicine, New York, NY, USA
| | - Diego Coira
- Department of Psychiatry and Behavioral Medicine, Hackensack University Medical Center, Hackensack, NJ, USA
| | - Fortunato Battaglia
- Department of Interprofessional Health Sciences & Health Administration, School of Health and Medical Sciences, Seton Hall University, South Orange, NJ, USA; Department of Psychiatry and Behavioral Medicine, Hackensack University Medical Center, Hackensack, NJ, USA
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Miyaguchi S, Kojima S, Kirimoto H, Tamaki H, Onishi H. Do Differences in Levels, Types, and Duration of Muscle Contraction Have an Effect on the Degree of Post-exercise Depression? Front Hum Neurosci 2016; 10:159. [PMID: 27199696 PMCID: PMC4850151 DOI: 10.3389/fnhum.2016.00159] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 03/31/2016] [Indexed: 12/04/2022] Open
Abstract
We conducted two experiments to determine how differences in muscle contraction levels, muscle contraction types, and movement duration affect degree of post-exercise depression (PED) after non-exhaustive, repetitive finger movement. Twelve healthy participants performed repetitive abduction movements of the right index finger at 2 Hz. In experiment 1, we examined the effects of muscle contraction levels at 10, 20, and 30% maximum voluntary contraction and the effects of muscle contraction types at isotonic and isometric contraction. In experiment 2, we examined the effects of movement duration at 2 and 6 min. Motor-evoked potentials (MEPs) were recorded from the right first dorsal interosseous muscle before movement tasks and 1–10 min after movement tasks. MEP amplitudes after isotonic contraction tasks were significantly smaller than those after isometric contraction tasks and decreased with increasing contraction levels, but were independent of movement duration. This study demonstrated that the degree of PED after non-exhaustive repetitive finger movement depended on muscle contraction levels and types. Thus, the degree of PED may depend on the levels of activity in the motor cortex during a movement task. This knowledge will aid in the design of rehabilitation protocols.
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Affiliation(s)
- Shota Miyaguchi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare Niigata, Japan
| | - Sho Kojima
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare Niigata, Japan
| | - Hikari Kirimoto
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare Niigata, Japan
| | - Hiroyuki Tamaki
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare Niigata, Japan
| | - Hideaki Onishi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare Niigata, Japan
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Raffin E, Richard N, Giraux P, Reilly KT. Primary motor cortex changes after amputation correlate with phantom limb pain and the ability to move the phantom limb. Neuroimage 2016; 130:134-144. [DOI: 10.1016/j.neuroimage.2016.01.063] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 01/11/2016] [Accepted: 01/15/2016] [Indexed: 01/25/2023] Open
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Cortical Mechanisms of Central Fatigue and Sense of Effort. PLoS One 2016; 11:e0149026. [PMID: 26859391 PMCID: PMC4747526 DOI: 10.1371/journal.pone.0149026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 01/26/2016] [Indexed: 11/19/2022] Open
Abstract
The purpose of this study was to investigate cortical mechanisms upstream to the corticospinal motor neuron that may be associated with central fatigue and sense of effort during and after a fatigue task. We used two different isometric finger abduction protocols to examine the effects of muscle activation and fatigue the right first dorsal interosseous (FDI) of 12 participants. One protocol was intended to assess the effects of muscle activation with minimal fatigue (control) and the other was intended to elicit central fatigue (fatigue). We hypothesized that high frequency repetitive transcranial magnetic stimulation (rTMS) of the supplementary motor area (SMA) would hasten recovery from central fatigue and offset a fatigue-induced increase in sense of effort by facilitating the primary motor cortex (M1). Constant force-sensation contractions were used to assess sense of effort associated with muscle contraction. Paired-pulse TMS was used to assess intracortical inhibition (ICI) and facilitation (ICF) in the active M1 and interhemispheric inhibitory (IHI) was assessed to determine if compensation occurs via the resting M1. These measures were made during and after the muscle contraction protocols. Corticospinal excitability progressively declined with fatigue in the active hemisphere. ICF increased at task failure and ICI was also reduced at task failure with no changes in IHI found. Although fatigue is associated with progressive reductions in corticospinal excitability, compensatory changes in inhibition and facilitation may act within, but not between hemispheres of the M1. rTMS of the SMA following fatigue enhanced recovery of maximal voluntary force and higher levels of ICF were associated with lower sense of effort following stimulation. rTMS of the SMA may have reduced the amount of upstream drive required to maintain motor output, thus contributing to a lower sense of effort and increased rate of recovery of maximal force.
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Šambaher N, Aboodarda SJ, Behm DG. Bilateral Knee Extensor Fatigue Modulates Force and Responsiveness of the Corticospinal Pathway in the Non-fatigued, Dominant Elbow Flexors. Front Hum Neurosci 2016; 10:18. [PMID: 26869902 PMCID: PMC4740948 DOI: 10.3389/fnhum.2016.00018] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 01/13/2016] [Indexed: 12/29/2022] Open
Abstract
Exercise-induced fatigue affects muscle performance and modulates corticospinal excitability in non-exercised muscles. The purpose of this study was to investigate the effect of bilateral knee extensor fatigue on dominant elbow flexor (EF) maximal voluntary force production and corticospinal excitability. Transcranial magnetic, transmastoid electrical and brachial plexus electrical stimulation (BPES) were used to investigate corticospinal, spinal, and muscle excitability of the dominant EF before and after a bilateral knee extensor fatiguing protocol or time matched rest period (control). For both sessions three stimuli were delivered every 1.5 s during the three pre-test time points and during the 1st, 3rd, 6th, 9th and 12th post-test 5 s EF isometric maximal voluntary contractions (MVC). In both conditions, overall, EF MVC force (p < 0.001) decreased progressively from repetition #1 to #12 during the post-test MVC protocol. EF MVC force (p < 0.001, ES = 0.9, Δ10.3%) decrements were more pronounced in the knee extensor fatigue intervention condition. In addition, there were no significant differences between conditions for biceps brachii electromyographic (EMG) activity (p = 0.43), motor evoked potentials (MEPs) amplitude (p = 0.908) or MEP silent period (SP; p = 0.776). However, the fatigue condition exhibited a lower MEP/cervicomedullary MEP (CMEP) ratio (p = 0.042, ES = 2.5, Δ25%) and a trend toward higher CMEP values (p = 0.08, ES = 0.5, Δ20.4%). These findings suggest that bilateral knee extensor fatigue can impair performance and modulate corticospinal excitability of the EF.
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Affiliation(s)
- Nemanja Šambaher
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's NL, Canada
| | - Saied Jalal Aboodarda
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's NL, Canada
| | - David George Behm
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's NL, Canada
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Aboodarda SJ, Šambaher N, Behm DG. Unilateral elbow flexion fatigue modulates corticospinal responsiveness in non-fatigued contralateral biceps brachii. Scand J Med Sci Sports 2015; 26:1301-1312. [PMID: 26633736 DOI: 10.1111/sms.12596] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2015] [Indexed: 11/30/2022]
Abstract
Exercise-induced fatigue can change motor performance in non-exercised muscles. The objective was to investigate unilateral elbow flexion (EF) fatigue effects on the maximal voluntary force (MVC) and corticospinal excitability of contralateral non-exercised biceps brachii (BB). Transcranial magnetic, transmastoid electrical, and brachial plexus electrical stimulation were used to elicit motor evoked potentials (MEP), cervicomedullary motor evoked potentials (CMEP), and compound muscle action potentials in the contralateral non-exercised BB of 12 participants before and after (i) two bouts of 100-s unilateral EF (fatigue) or (ii) control. Three stimuli were evoked every 1.5 s during a series of 6-s isometric EF at 100%, 50%, and 5% of MVC. The non-exercised EF MVC force, electromyographic activity, and voluntary activation were not significantly different between fatigue and control. Non-exercised BB MEP and CMEP amplitudes during 100% MVCs demonstrated significantly higher (P = 0.03) and lower values (P = 0.01), respectively, after fatigue compared with control. There was no difference between the two conditions for MEP and CMEP amplitudes during 50% and 5% MVCs. Unilateral exercise-induced EF fatigue did not lead to cross-over central fatigue to the contralateral homologous muscle but enhanced the supraspinal responsiveness (MEP/CMEP) of the neural circuitries supplying central commands to non-exercised muscles at higher contraction intensity.
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Affiliation(s)
- S J Aboodarda
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - N Šambaher
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - D G Behm
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.
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Aboodarda SJ, Copithorne DB, Pearcey GE, Button DC, Power KE. Changes in supraspinal and spinal excitability of the biceps brachii following brief, non-fatiguing submaximal contractions of the elbow flexors in resistance-trained males. Neurosci Lett 2015; 607:66-71. [DOI: 10.1016/j.neulet.2015.09.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 08/28/2015] [Accepted: 09/23/2015] [Indexed: 11/28/2022]
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Klomjai W, Katz R, Lackmy-Vallée A. Basic principles of transcranial magnetic stimulation (TMS) and repetitive TMS (rTMS). Ann Phys Rehabil Med 2015; 58:208-213. [PMID: 26319963 DOI: 10.1016/j.rehab.2015.05.005] [Citation(s) in RCA: 380] [Impact Index Per Article: 42.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 05/31/2015] [Accepted: 05/31/2015] [Indexed: 01/11/2023]
Abstract
Transcranial magnetic stimulation (TMS) and repetitive TMS (rTMS) are indirect and non-invasive methods used to induce excitability changes in the motor cortex via a wire coil generating a magnetic field that passes through the scalp. Today, TMS has become a key method to investigate brain functioning in humans. Moreover, because rTMS can lead to long-lasting after-effects in the brain, it is thought to be able to induce plasticity. This tool appears to be a potential therapy for neurological and psychiatric diseases. However, the physiological mechanisms underlying the effects induced by TMS and rTMS have not yet been clearly identified. The purpose of the present review is to summarize the main knowledge available for TMS and rTMS to allow for understanding their mode of action and to specify the different parameters that influence their effects. This review takes an inventory of the most-used rTMS paradigms in clinical research and exhibits the hypotheses commonly assumed to explain rTMS after-effects.
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Affiliation(s)
- Wanalee Klomjai
- Faculty of Physical Therapy, Mahidol University, 73170 Nakonpathom, Thailand
| | - Rose Katz
- UPMC Université Paris 06, CNRS, Inserm, laboratoire d'imagerie biomédicale, Sorbonne universités, 75013 Paris, France; Service de médecine physique et réadaptation, groupe hospitalier Pitié-Salpêtrière, AP-HP, France
| | - Alexandra Lackmy-Vallée
- UPMC Université Paris 06, CNRS, Inserm, laboratoire d'imagerie biomédicale, Sorbonne universités, 75013 Paris, France.
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Kotan S, Kojima S, Miyaguchi S, Sugawara K, Onishi H. Depression of corticomotor excitability after muscle fatigue induced by electrical stimulation and voluntary contraction. Front Hum Neurosci 2015; 9:363. [PMID: 26150781 PMCID: PMC4472998 DOI: 10.3389/fnhum.2015.00363] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 06/08/2015] [Indexed: 11/13/2022] Open
Abstract
In this study, we examined the effect of muscle fatigue induced by tetanic electrical stimulation (ES) and submaximal isometric contraction on corticomotor excitability. Experiments were performed in a cross-over design. Motor-evoked potentials (MEPs) were elicited by transcranial magnetic stimulation (TMS). Corticomotor excitability was recorded before and after thumb opposition muscle fatigue tasks, in which 10% of the maximal tension intensity was induced by tetanic ES or voluntary contraction (VC). The participants were 10 healthy individuals who performed each task for 10 min. Surface electrodes placed over the abductor pollicis brevis (APB) muscle recorded MEPs. F- and M-waves were elicited from APB by supramaximal ES of the median nerve. After the tetanic ES- and VC tasks, MEP amplitudes were significantly lower than before the task. However, F- and M-wave amplitudes remained unchanged. These findings suggest that corticospinal excitability is reduced by muscle fatigue as a result of intracortical inhibitory mechanisms. Our results also suggest that corticomotor excitability is reduced by muscle fatigue caused by both VC and tetanic ES.
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Affiliation(s)
- Shinichi Kotan
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare Niigata, Japan
| | - Sho Kojima
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare Niigata, Japan
| | - Shota Miyaguchi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare Niigata, Japan
| | - Kazuhiro Sugawara
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare Niigata, Japan
| | - Hideaki Onishi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare Niigata, Japan
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Weavil JC, Sidhu SK, Mangum TS, Richardson RS, Amann M. Intensity-dependent alterations in the excitability of cortical and spinal projections to the knee extensors during isometric and locomotor exercise. Am J Physiol Regul Integr Comp Physiol 2015; 308:R998-1007. [PMID: 25876651 DOI: 10.1152/ajpregu.00021.2015] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 04/08/2015] [Indexed: 11/22/2022]
Abstract
We investigated the role of exercise intensity and associated central motor drive in determining corticomotoneuronal excitability. Ten participants performed a series of nonfatiguing (3 s) isometric single-leg knee extensions (ISO; 10-100% of maximal voluntary contractions, MVC) and cycling bouts (30-160% peak aerobic capacity, W peak). At various exercise intensities, electrical potentials were evoked in the vastus lateralis (VL) and rectus femoris (RF) via transcranial magnetic stimulation (motor-evoked potentials, MEP), and electrical stimulation of both the cervicomedullary junction (cervicomedullary evoked potentials, CMEP) and the femoral nerve (maximal M-waves, M max). Whereas M max remained unchanged in both muscles (P > 0.40), voluntary electromyographic activity (EMG) increased in an exercise intensity-dependent manner for ISO and cycling exercise in VL and RF (both P < 0.001). During ISO exercise, MEPs and CMEPs progressively increased in VL and RF until a plateau was reached at ∼ 75% MVC; further increases in contraction intensity did not cause additional changes (P > 0.35). During cycling exercise, VL-MEPs and CMEPs progressively increased by ∼ 65% until a plateau was reached at W peak. In contrast, RF MEPs and CMEPs progressively increased by ∼ 110% throughout the tested cycling intensities without the occurrence of a plateau. Furthermore, alterations in EMG below the plateau influenced corticomotoneuronal excitability similarly between exercise modalities. In both exercise modalities, the MEP-to-CMEP ratio did not change with exercise intensity (P > 0.22). In conclusion, increases in exercise intensity and EMG facilitates the corticomotoneuronal pathway similarly in isometric knee extension and locomotor exercise until a plateau occurs at a submaximal exercise intensity. This facilitation appears to be primarily mediated by increases in excitability of the motoneuron pool.
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Affiliation(s)
- J C Weavil
- Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah
| | - S K Sidhu
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - T S Mangum
- Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah
| | - R S Richardson
- Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah; Department of Internal Medicine, University of Utah, Salt Lake City, Utah; Geriatric Research, Education, and Clinical Center, Salt Lake City Veterans Affairs Medical Center, Salt Lake City, Utah
| | - M Amann
- Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah; Department of Internal Medicine, University of Utah, Salt Lake City, Utah; Geriatric Research, Education, and Clinical Center, Salt Lake City Veterans Affairs Medical Center, Salt Lake City, Utah
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Vaseghi B, Zoghi M, Jaberzadeh S. How does anodal transcranial direct current stimulation of the pain neuromatrix affect brain excitability and pain perception? A randomised, double-blind, sham-control study. PLoS One 2015; 10:e0118340. [PMID: 25738603 PMCID: PMC4349802 DOI: 10.1371/journal.pone.0118340] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 01/12/2015] [Indexed: 12/11/2022] Open
Abstract
Background Integration of information between multiple cortical regions of the pain neuromatrix is thought to underpin pain modulation. Although altered processing in the primary motor (M1) and sensory (S1) cortices is implicated in separate studies, the simultaneous changes in and the relationship between these regions are unknown yet. The primary aim was to assess the effects of anodal transcranial direct current stimulation (a-tDCS) over superficial regions of the pain neuromatrix on M1 and S1 excitability. The secondary aim was to investigate how M1 and S1 excitability changes affect sensory (STh) and pain thresholds (PTh). Methods Twelve healthy participants received 20 min a-tDCS under five different conditions including a-tDCS of M1, a-tDCS of S1, a-tDCS of DLPFC, sham a-tDCS, and no-tDCS. Excitability of dominant M1 and S1 were measured before, immediately, and 30 minutes after intervention respectively. Moreover, STh and PTh to peripheral electrical and mechanical stimulation were evaluated. All outcome measures were assessed at three time-points of measurement by a blind rater. Results A-tDCS of M1 and dorsolateral prefrontal cortex (DLPFC) significantly increased brain excitability in M1 (p < 0.05) for at least 30 min. Following application of a-tDCS over the S1, the amplitude of the N20-P25 component of SEPs increased immediately after the stimulation (p < 0.05), whilst M1 stimulation decreased it. Compared to baseline values, significant STh and PTh increase was observed after a-tDCS of all three stimulated areas. Except in M1 stimulation, there was significant PTh difference between a-tDCS and sham tDCS. Conclusion a-tDCS of M1 is the best spots to enhance brain excitability than a-tDCS of S1 and DLPFC. Surprisingly, a-tDCS of M1 and S1 has diverse effects on S1 and M1 excitability. A-tDCS of M1, S1, and DLPFC increased STh and PTh levels. Given the placebo effects of a-tDCS of M1 in pain perception, our results should be interpreted with caution, particularly with respect to the behavioural aspects of pain modulation. Trial Registration Australian New Zealand Clinical Trials, ACTRN12614000817640, http://www.anzctr.org.au/.
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Affiliation(s)
- Bita Vaseghi
- Department of Physiotherapy, School of Primary Health Care, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC, Australia
- * E-mail:
| | - Maryam Zoghi
- Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Melbourne, VIC, Australia
| | - Shapour Jaberzadeh
- Department of Physiotherapy, School of Primary Health Care, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC, Australia
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Edwardson MA, Avery DH, Fetz EE. Volitional muscle activity paired with transcranial magnetic stimulation increases corticospinal excitability. Front Neurosci 2015; 8:442. [PMID: 25628525 PMCID: PMC4290610 DOI: 10.3389/fnins.2014.00442] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 12/16/2014] [Indexed: 01/17/2023] Open
Abstract
Studies of activity-dependent stimulation in non-human primates suggest that pairing each instance of volitional muscle activity with immediate intracortical stimulation causes long-term-potentiation-like effects. This technique holds promise for clinical rehabilitation, yet few investigators have tested activity-dependent stimulation in human subjects. In addition, no one has studied activity-dependent stimulation on the cortical representation for two separate target muscles in human subjects. We hypothesized that 40 min of transcranial magnetic stimulation (TMS) triggered from ballistic muscle activity at a mean repetition rate of 1 Hz would cause greater increases in corticospinal excitability than TMS-cued muscle activity, and that these changes would be specific to the muscle of study. Ten healthy human subjects participated in 4 separate sessions in this crossover study: (1) visually cued volitional activation of the abductor pollicis brevis (APB) muscle triggering TMS (APB-Triggered TMS), (2) volitional activation of APB in response to TMS delivered from a recording of the prior APB-Triggered TMS session (TMS-Cued APB), (3) visually cued volitional activation of the extensor digitorum (ED) triggering TMS (ED-Triggered TMS), and (4) volitional activation of ED in response to TMS delivered from a recording of the prior ED-Triggered TMS session (TMS-Cued ED). Contrary to our hypothesis, we discovered evidence of increased corticospinal excitability for all conditions as measured by change in area of the motor evoked potential. We conclude that single TMS pulses paired either before or after muscle activity may increase corticospinal excitability and that further studies are needed to clarify the optimal time window for inducing neural plasticity with activity-dependent stimulation. These findings will inform the design of future activity-dependent stimulation protocols for clinical rehabilitation.
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Affiliation(s)
| | - David H Avery
- Department of Psychiatry and Behavioral Sciences, University of Washington Seattle, WA, USA
| | - Eberhard E Fetz
- Department of Physiology and Biophysics, University of Washington Seattle, WA, USA
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The role of neuroplasticity in experimental neck pain: A study of potential mechanisms impeding clinical outcomes of training. ACTA ACUST UNITED AC 2014; 19:288-93. [DOI: 10.1016/j.math.2014.04.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 03/07/2014] [Accepted: 04/10/2014] [Indexed: 12/15/2022]
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Scalise A, Pittaro-Cadore I, Serafini A, Simeoni S, Fratticci L, Ecoretti E, Gigli GL. Transcranial magnetic stimulation in sleep fragmentation: a model to better understand sleep disorders. Sleep Med 2014; 15:1386-91. [PMID: 25194582 DOI: 10.1016/j.sleep.2014.06.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/08/2014] [Accepted: 06/05/2014] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To investigate practice-dependent plasticity and cortical inhibition/excitability in good sleepers after a night of sleep fragmentation (SF), by means of transcranial magnetic stimulation (TMS). METHODS In basal condition (BC), after a full night of spontaneous sleep, and in fragmented condition (FC), after a fragmented night of sleep, motor evoked potential (MEP) amplitude, motor threshold (MT), silent period (SP), and intracortical inhibition were assessed. In both conditions subjects performed, also, a bimanual motor task: MEPs were recorded before and after exercise, and after rest. We evaluated the presence of post-exercise facilitation and delayed facilitation. Subjects reported their alertness level (Stanford Sleepiness Scale-SSS). RESULTS MT and SSS were significantly increased in SF. Instead, no significant differences for MEP amplitude or SP or intracortical inhibition were found. In both conditions post-exercise facilitation and delayed facilitation were present. CONCLUSION SF produces disruption of nocturnal sleep and increases daytime sleepiness. Confirmatory features of this clinical behaviour could be that in FC we observed a significant increase in SSS and in MT. SF was unable to modify cortical inhibition\excitability and\or to influence plasticity-related parameters. These results seem inconsistent with some of TMS alterations observed in sleep deprivation (SD) and restless legs syndrome (RLS). We suggest that SD and SF represent different phenomena that can depend on various networks acting on motor cortex. We speculate that alterations in cortical excitability found in RLS are intrinsically related to the underlying disease itself and are not instead directly associated with the SF present in RLS.
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Affiliation(s)
- Anna Scalise
- Center of Sleep Medicine, Neurology Clinic, University-Hospital S. Maria della Misericordia, Udine, Italy.
| | - Italo Pittaro-Cadore
- Center of Sleep Medicine, Neurology Clinic, University-Hospital S. Maria della Misericordia, Udine, Italy
| | - Anna Serafini
- Center of Sleep Medicine, Neurology Clinic, University-Hospital S. Maria della Misericordia, Udine, Italy
| | - Sara Simeoni
- Center of Sleep Medicine, Neurology Clinic, University-Hospital S. Maria della Misericordia, Udine, Italy
| | - Lara Fratticci
- Center of Sleep Medicine, Neurology Clinic, University-Hospital S. Maria della Misericordia, Udine, Italy
| | - Elisa Ecoretti
- Center of Sleep Medicine, Neurology Clinic, University-Hospital S. Maria della Misericordia, Udine, Italy
| | - Gian Luigi Gigli
- Center of Sleep Medicine, Neurology Clinic, University-Hospital S. Maria della Misericordia, Udine, Italy
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Heise KF, Niehoff M, Feldheim JF, Liuzzi G, Gerloff C, Hummel FC. Differential behavioral and physiological effects of anodal transcranial direct current stimulation in healthy adults of younger and older age. Front Aging Neurosci 2014; 6:146. [PMID: 25071555 PMCID: PMC4091308 DOI: 10.3389/fnagi.2014.00146] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 06/16/2014] [Indexed: 01/19/2023] Open
Abstract
Changes in γ-aminobutyric acid (GABA) mediated synaptic transmission have been associated with age-related motor and cognitive functional decline. Since anodal transcranial direct current stimulation (atDCS) has been suggested to target cortical GABAergic inhibitory interneurons, its potential for the treatment of deficient inhibitory activity and functional decline is being increasingly discussed. Therefore, after-effects of a single session of atDCS on resting-state and event-related short-interval intracortical inhibition (SICI) as evaluated with double-pulse TMS and dexterous manual performance were examined using a sham-controlled cross-over design in a sample of older and younger participants. The atDCS effect on resting-state inhibition differed in direction, magnitude, and timing, i.e., late relative release of inhibition in the younger and early relative increase in inhibition in the older. More pronounced release of event-related inhibition after atDCS was exclusively seen in the older. Event-related modulation of inhibition prior to stimulation predicted the magnitude of atDCS-induced effects on resting-state inhibition. Specifically, older participants with high modulatory capacity showed a disinhibitory effect comparable to the younger. Beneficial effects on behavior were mainly seen in the older and in tasks requiring higher dexterity, no clear association with physiological changes was found. Differential effects of atDCS on SICI, discussed to reflect GABAergic inhibition at the level of the primary motor cortex, might be distinct in older and younger participants depending on the functional integrity of the underlying neural network. Older participants with preserved modulatory capacity, i.e., a physiologically “young” motor network, were more likely to show a disinhibitory effect of atDCS. These results favor individually tailored application of tDCS with respect to specific target groups.
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Affiliation(s)
- Kirstin-Friederike Heise
- Brain Imaging and Neurostimulation (BINS) Laboratory, Department of Neurology, University Medical Center Hamburg-Eppendorf Hamburg, Germany
| | - Martina Niehoff
- Brain Imaging and Neurostimulation (BINS) Laboratory, Department of Neurology, University Medical Center Hamburg-Eppendorf Hamburg, Germany
| | - J-F Feldheim
- Brain Imaging and Neurostimulation (BINS) Laboratory, Department of Neurology, University Medical Center Hamburg-Eppendorf Hamburg, Germany
| | - Gianpiero Liuzzi
- Brain Imaging and Neurostimulation (BINS) Laboratory, Department of Neurology, University Medical Center Hamburg-Eppendorf Hamburg, Germany ; Department of Neurology, University Hospital Zürich Zürich, Switzerland
| | - Christian Gerloff
- Brain Imaging and Neurostimulation (BINS) Laboratory, Department of Neurology, University Medical Center Hamburg-Eppendorf Hamburg, Germany
| | - Friedhelm C Hummel
- Brain Imaging and Neurostimulation (BINS) Laboratory, Department of Neurology, University Medical Center Hamburg-Eppendorf Hamburg, Germany
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Corticomotor Excitability During a Noxious Stimulus Before and After Exercise in Women With Fibromyalgia. J Clin Neurophysiol 2014; 31:94-8. [DOI: 10.1097/wnp.0000000000000025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Kashigar A, Udupa K, Fish J, Chen R. Neurophysiological assessment of fatigue in electrical injury patients. Exp Brain Res 2014; 232:1013-23. [PMID: 24381088 DOI: 10.1007/s00221-013-3812-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 12/15/2013] [Indexed: 10/25/2022]
Abstract
To investigate for the presence of central and peripheral physiological fatigue in electrical injury (EI) patients with experiential fatigue. Eight EI patients and eight age-matched healthy volunteers were recruited. Motor evoked potentials (MEP) following transcranial magnetic stimulation (TMS) and M-waves from ulnar nerve stimulation at the wrist were measured from the right abductor digiti minimi. Fatigue was induced by 2 min of maximal voluntary contraction, and subjects were followed for 15 min of recovery. The experiment was performed twice for each subject. In one of the two sessions (randomly assigned), a blood pressure (BP) cuff was inflated during the first 75 s of recovery period to prolong muscle ischemia. Baseline measures showed no difference in central and peripheral conduction times. Cortical silent period was prolonged in patients compared to controls with no differences in abduction force. Decrement of MEP amplitude with consecutive TMS pulses was observed in the post-recovery period only with EI patients who had prolonged muscle ischemia induced by the BP cuff. The post-exercise M-wave area during contraction was significantly higher for patients. Prolonged cortical silent period in EI patients suggests that they had increased GABAB receptor-mediated cortical inhibition. The ischemia-induced decrement in consecutive MEP amplitudes post-exercise demonstrates greater physiological fatigue in EI patients after exercise. The greater increase in M-wave area of EI patients post-exercise suggests larger decrease in conduction velocity of muscle action potentials with exercise. These findings provide preliminary physiological correlates for increased central and peripheral fatigue in EI patients with experiential fatigue.
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Affiliation(s)
- Aidin Kashigar
- Toronto Western Research Institute, University Health Network, Toronto, ON, Canada
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Teo WP, Rodrigues JP, Mastaglia FL, Thickbroom GW. Modulation of corticomotor excitability after maximal or sustainable-rate repetitive finger movement is impaired in Parkinson's disease and is reversed by levodopa. Clin Neurophysiol 2013; 125:562-8. [PMID: 24095151 DOI: 10.1016/j.clinph.2013.09.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 08/28/2013] [Accepted: 09/08/2013] [Indexed: 11/29/2022]
Abstract
OBJECTIVES In healthy subjects, fatiguing exercises induce a period of post-exercise corticomotor depression (PECD) that is absent in Parkinson's disease (PD). Our objective is to determine the time-course of corticomotor excitability changes following a 10-s repetitive index finger flexion-extension task performed at maximal voluntary rate (MVR) and a slower sustainable rate (MSR) in PD patients OFF and ON levodopa. METHODS In 11 PD patients and 10 healthy age-matched controls, motor evoked potentials (MEPs) were recorded from the extensor indicis proprius (EIP) and first dorsal interosseous (FDI) muscles of the dominant arm immediately after the two tasks and at 2-min intervals for 10 min. RESULTS In the OFF condition the PECD was absent in the two test muscles after both the MVR and MSR tasks. In the ON condition finger movement kinematics improved and a period of PECD comparable to that in controls was present after both tasks. CONCLUSION The absence of PECD in PD subjects off medication indicates a persisting increase in corticomotor excitability after non-fatiguing repetitive finger movement that is reversed by levodopa. SIGNIFICANCE Dopamine depletion is associated with impaired modulation of corticomotor excitability after non-fatiguing repetitive finger movement.
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Affiliation(s)
- Wei-Peng Teo
- Australian Neuro-Muscular Research Institute, Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Western Australia, Australia
| | - Julian P Rodrigues
- Australian Neuro-Muscular Research Institute, Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Western Australia, Australia
| | - Frank L Mastaglia
- Australian Neuro-Muscular Research Institute, Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Western Australia, Australia
| | - Gary W Thickbroom
- Australian Neuro-Muscular Research Institute, Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Western Australia, Australia.
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Morris G, Maes M. Myalgic encephalomyelitis/chronic fatigue syndrome and encephalomyelitis disseminata/multiple sclerosis show remarkable levels of similarity in phenomenology and neuroimmune characteristics. BMC Med 2013; 11:205. [PMID: 24229326 PMCID: PMC3847236 DOI: 10.1186/1741-7015-11-205] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Accepted: 08/15/2013] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND 'Encephalomyelitis disseminata' (multiple sclerosis) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are both classified as diseases of the central nervous system by the World Health Organization. This review aims to compare the phenomenological and neuroimmune characteristics of MS with those of ME/CFS. DISCUSSION There are remarkable phenomenological and neuroimmune overlaps between both disorders. Patients with ME/CFS and MS both experience severe levels of disabling fatigue and a worsening of symptoms following exercise and resort to energy conservation strategies in an attempt to meet the energy demands of day-to-day living. Debilitating autonomic symptoms, diminished cardiac responses to exercise, orthostatic intolerance and postural hypotension are experienced by patients with both illnesses. Both disorders show a relapsing-remitting or progressive course, while infections and psychosocial stress play a large part in worsening of fatigue symptoms. Activated immunoinflammatory, oxidative and nitrosative (O+NS) pathways and autoimmunity occur in both illnesses. The consequences of O+NS damage to self-epitopes is evidenced by the almost bewildering and almost identical array of autoantibodies formed against damaged epitopes seen in both illnesses. Mitochondrial dysfunctions, including lowered levels of ATP, decreased phosphocreatine synthesis and impaired oxidative phosphorylation, are heavily involved in the pathophysiology of both MS and ME/CFS. The findings produced by neuroimaging techniques are quite similar in both illnesses and show decreased cerebral blood flow, atrophy, gray matter reduction, white matter hyperintensities, increased cerebral lactate and choline signaling and lowered acetyl-aspartate levels. SUMMARY This review shows that there are neuroimmune similarities between MS and ME/CFS. This further substantiates the view that ME/CFS is a neuroimmune illness and that patients with MS are immunologically primed to develop symptoms of ME/CFS.
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Affiliation(s)
- Gerwyn Morris
- Tir Na Nog, Pembrey, Llanelli, UK
- Department of Psychiatry, Chulalongkorn University, Bangkok, Thailand
| | - Michael Maes
- Department of Psychiatry, Chulalongkorn University, Bangkok, Thailand
- Department of Psychiatry, Deakin University, Geelong, Australia
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Miyaguchi S, Onishi H, Kojima S, Sugawara K, Tsubaki A, Kirimoto H, Tamaki H, Yamamoto N. Corticomotor excitability induced by anodal transcranial direct current stimulation with and without non-exhaustive movement. Brain Res 2013; 1529:83-91. [DOI: 10.1016/j.brainres.2013.07.026] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 07/13/2013] [Accepted: 07/18/2013] [Indexed: 12/01/2022]
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Bastani A, Jaberzadeh S. Differential modulation of corticospinal excitability by different current densities of anodal transcranial direct current stimulation. PLoS One 2013; 8:e72254. [PMID: 23991076 PMCID: PMC3750044 DOI: 10.1371/journal.pone.0072254] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 07/09/2013] [Indexed: 12/03/2022] Open
Abstract
Background Novel non-invasive brain stimulation techniques such as transcranial direct current stimulation (tDCS) have been developed in recent years. TDCS-induced corticospinal excitability changes depend on two important factors current intensity and stimulation duration. Despite clinical success with existing tDCS parameters, optimal protocols are still not entirely set. Objective/hypothesis The current study aimed to investigate the effects of four different anodal tDCS (a-tDCS) current densities on corticospinal excitability. Methods Four current intensities of 0.3, 0.7, 1.4 and 2 mA resulting in current densities (CDs) of 0.013, 0.029, 0.058 and 0.083 mA/cm2 were applied on twelve right-handed (mean age 34.5±10.32 yrs) healthy individuals in different sessions at least 48 hours apart. a-tDCS was applied continuously for 10 minute, with constant active and reference electrode sizes of 24 and 35 cm2 respectively. The corticospinal excitability of the extensor carpi radialis muscle (ECR) was measured before and immediately after the intervention and at 10, 20 and 30 minutes thereafter. Results Post hoc comparisons showed significant differences in corticospinal excitability changes for CDs of 0.013 mA/cm2 and 0.029 mA/cm2 (P = 0.003). There were no significant differences between excitability changes for the 0.013 mA/cm2 and 0.058 mA/cm2 (P = 0.080) or 0.013 mA/cm2 and 0.083 mA/cm2 (P = 0.484) conditions. Conclusion This study found that a-tDCS with a current density of 0.013 mA/cm2 induces significantly larger corticospinal excitability changes than CDs of 0.029 mA/cm2. The implication is that might help to avoid applying unwanted amount of current to the cortical areas.
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Affiliation(s)
- Andisheh Bastani
- Department of Physiotherapy, School of Primary Health Care, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia.
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