1
|
Pavey N, Hannaford A, van den Bos M, Kiernan MC, Menon P, Vucic S. Distinct neuronal circuits mediate cortical hyperexcitability in amyotrophic lateral sclerosis. Brain 2024; 147:2344-2356. [PMID: 38374770 DOI: 10.1093/brain/awae049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 01/16/2024] [Accepted: 01/27/2024] [Indexed: 02/21/2024] Open
Abstract
Cortical hyperexcitability is an important pathophysiological mechanism in amyotrophic lateral sclerosis (ALS), reflecting a complex interaction of inhibitory and facilitatory interneuronal processes that evolves in the degenerating brain. The advances in physiological techniques have made it possible to interrogate progressive changes in the motor cortex. Specifically, the direction of transcranial magnetic stimulation (TMS) stimulus within the primary motor cortex can be utilized to influence descending corticospinal volleys and to thereby provide information about distinct interneuronal circuits. Cortical motor function and cognition was assessed in 29 ALS patients with results compared to healthy volunteers. Cortical dysfunction was assessed using threshold-tracking TMS to explore alterations in short interval intracortical inhibition (SICI), short interval intracortical facilitation (SICF), the index of excitation and stimulus response curves using a figure-of-eight coil with the coil oriented relative to the primary motor cortex in a posterior-anterior, lateral-medial and anterior-posterior direction. Mean SICI, between interstimulus interval of 1-7 ms, was significantly reduced in ALS patients compared to healthy controls when assessed with the coil oriented in posterior-anterior (P = 0.044) and lateral-medial (P = 0.005) but not the anterior-posterior (P = 0.08) directions. A significant correlation between mean SICI oriented in a posterior-anterior direction and the total Edinburgh Cognitive and Behavioural ALS Screen score (Rho = 0.389, P = 0.037) was evident. In addition, the mean SICF, between interstimulus interval 1-5 ms, was significantly increased in ALS patients when recorded with TMS coil oriented in posterior-anterior (P = 0.035) and lateral-medial (P < 0.001) directions. In contrast, SICF recorded with TMS coil oriented in the anterior-posterior direction was comparable between ALS and controls (P = 0.482). The index of excitation was significantly increased in ALS patients when recorded with the TMS coil oriented in posterior-anterior (P = 0.041) and lateral-medial (P = 0.003) directions. In ALS patients, a significant increase in the stimulus response curve gradient was evident compared to controls when recorded with TMS coil oriented in posterior-anterior (P < 0.001), lateral-medial (P < 0.001) and anterior-posterior (P = 0.002) directions. The present study has established that dysfunction of distinct interneuronal circuits mediates the development of cortical hyperexcitability in ALS. Specifically, complex interplay between inhibitory circuits and facilitatory interneuronal populations, that are preferentially activated by stimulation in posterior-to-anterior or lateral-to-medial directions, promotes cortical hyperexcitability in ALS. Mechanisms that underlie dysfunction of these specific cortical neuronal circuits will enhance understanding of the pathophysiological processes in ALS, with the potential to uncover focussed therapeutic targets.
Collapse
Affiliation(s)
- Nathan Pavey
- Brain and Nerve Research Centre, Concord Clinical School, The University of Sydney, Concord Hospital, Sydney, NSW 2139, Australia
| | - Andrew Hannaford
- Brain and Nerve Research Centre, Concord Clinical School, The University of Sydney, Concord Hospital, Sydney, NSW 2139, Australia
| | - Mehdi van den Bos
- Brain and Nerve Research Centre, Concord Clinical School, The University of Sydney, Concord Hospital, Sydney, NSW 2139, Australia
| | - Matthew C Kiernan
- Brain and Mind Centre, The University of Sydney, Sydney, NSW 2139, Australia
- Department of Neurology, Royal Prince Alfred Hospital, Sydney, NSW 2139, Australia
| | - Parvathi Menon
- Brain and Nerve Research Centre, Concord Clinical School, The University of Sydney, Concord Hospital, Sydney, NSW 2139, Australia
| | - Steve Vucic
- Brain and Nerve Research Centre, Concord Clinical School, The University of Sydney, Concord Hospital, Sydney, NSW 2139, Australia
| |
Collapse
|
2
|
Ikarashi K, Sato D, Edama M, Fujimoto T, Ochi G, Yamashiro K. Fluctuation of fine motor skills throughout the menstrual cycle in women. Sci Rep 2024; 14:15079. [PMID: 38956128 PMCID: PMC11219923 DOI: 10.1038/s41598-024-65823-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 06/24/2024] [Indexed: 07/04/2024] Open
Abstract
The effect of the menstrual cycle on fine motor skills is unclear. This study determined whether the menstrual cycle affected fine motor skills and related neural activities. Nineteen women with regular menstrual cycles were tested for fine motor skills using two types of tasks: grooved pegboard task (GPT), which evaluates motor control with high freedom of movements, and force modulation task (FMT), which evaluates more complex and fine motor control with low freedom of movements. We also assessed primary motor cortex intracortical circuits and sensorimotor integration using paired-pulse transcranial magnetic stimulation to reveal why the menstrual cycle affects fine motor skills. The present study indicated that fine motor skills assessed by FMT varied throughout the menstrual cycle while those measured by GPT did not. These results suggest that fine motor skills requiring more complex and fine control may be affected by the menstrual cycle. Additionally, changes in fine motor skills throughout the menstrual cycle may be associated with the severity of menstruation-related symptoms.
Collapse
Affiliation(s)
- Koyuki Ikarashi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-Cho, Kita-Ku, Niigata, 950-3198, Japan
- Department of Health and Sports, Niigata University of Health and Welfare, Niigata, Japan
| | - Daisuke Sato
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-Cho, Kita-Ku, Niigata, 950-3198, Japan.
- Department of Health and Sports, Niigata University of Health and Welfare, Niigata, Japan.
| | - Mutsuaki Edama
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-Cho, Kita-Ku, Niigata, 950-3198, Japan
- Department of Physical Therapy, Niigata University of Health and Welfare, Niigata, Japan
| | - Tomomi Fujimoto
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-Cho, Kita-Ku, Niigata, 950-3198, Japan
- Department of Health and Sports, Niigata University of Health and Welfare, Niigata, Japan
| | - Genta Ochi
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-Cho, Kita-Ku, Niigata, 950-3198, Japan
- Department of Health and Sports, Niigata University of Health and Welfare, Niigata, Japan
| | - Koya Yamashiro
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-Cho, Kita-Ku, Niigata, 950-3198, Japan
- Department of Health and Sports, Niigata University of Health and Welfare, Niigata, Japan
| |
Collapse
|
3
|
Lanza G, Salemi M, Mogavero MP, Catania V, Galeano A, Garifoli A, Lanuzza B, Morreale M, Tripodi M, Cantone M, Cappellani F, Concerto C, Rodolico A, Pennisi M, Bella R, Ferri R. Targeting the adenosinergic system in restless legs syndrome: A pilot, "proof-of-concept" placebo-controlled TMS-based protocol. PLoS One 2024; 19:e0302829. [PMID: 38728342 PMCID: PMC11086884 DOI: 10.1371/journal.pone.0302829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 04/10/2024] [Indexed: 05/12/2024] Open
Abstract
Restless Legs Syndrome (RLS) is a common sleep disorder characterized by an urge to move the legs that is responsive to movement (particularly during rest), periodic leg movements during sleep, and hyperarousal. Recent evidence suggests that the involvement of the adenosine system may establish a connection between dopamine and glutamate dysfunction in RLS. Transcranial magnetic stimulation (TMS) is a non-invasive electrophysiological technique widely applied to explore brain electrophysiology and neurochemistry under different experimental conditions. In this pilot study protocol, we aim to investigate the effects of dipyridamole (a well-known enhancer of adenosinergic transmission) and caffeine (an adenosine receptor antagonist) on measures of cortical excitation and inhibition in response to TMS in patients with primary RLS. Initially, we will assess cortical excitability using both single- and paired-pulse TMS in patients with RLS. Then, based on the measures obtained, we will explore the effects of dipyridamole and caffeine, in comparison to placebo, on various TMS parameters related to cortical excitation and inhibition. Finally, we will evaluate the psycho-cognitive performance of RLS patients to screen them for cognitive impairment and/or mood-behavioral dysfunction, thus aiming to correlate psycho-cognitive findings with TMS data. Overall, this study protocol will be the first to shed lights on the neurophysiological mechanisms of RLS involving the modulation of the adenosine system, thus potentially providing a foundation for innovative "pharmaco-TMS"-based treatments. The distinctive TMS profile observed in RLS holds indeed the potential utility for both diagnosis and treatment, as well as for patient monitoring. As such, it can be considered a target for both novel pharmacological (i.e., drug) and non-pharmacological (e.g., neuromodulatory), "TMS-guided", interventions.
Collapse
Affiliation(s)
- Giuseppe Lanza
- Oasi Research Institute-IRCCS, Troina, Italy
- Department of Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy
| | | | - Maria P. Mogavero
- Vita-Salute San Raffaele University, Milan, Italy
- Division of Neuroscience, San Raffaele Scientific Institute, Sleep Disorders Center, Milan, Italy
| | | | | | | | | | | | | | - Mariagiovanna Cantone
- Neurology Unit, Policlinico University Hospital “G. Rodolico-San Marco”, Catania, Italy
| | - Francesco Cappellani
- Ophtalomolgy Unit, Policlinico University Hospital “G. Rodolico-San Marco”, Catania, Italy
| | - Carmen Concerto
- Psychiatry Unit, Policlinico University Hospital “G. Rodolico-San Marco”, Catania, Italy
| | - Alessandro Rodolico
- Psychiatry Unit, Policlinico University Hospital “G. Rodolico-San Marco”, Catania, Italy
| | - Manuela Pennisi
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Rita Bella
- Department of Medical and Surgical Sciences and Advanced Technologies, University of Catania, Catania, Italy
| | | |
Collapse
|
4
|
Crouzier M, Avrillon S, Hug F, Cattagni T. Horizontal foot orientation affects the distribution of neural drive between gastrocnemii during plantarflexion, without changing neural excitability. J Appl Physiol (1985) 2024; 136:786-798. [PMID: 38205551 DOI: 10.1152/japplphysiol.00536.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 12/21/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024] Open
Abstract
The distribution of activation among muscles from the same anatomical group can be affected by the mechanical constraints of the task, such as limb orientation. For example, the distribution of activation between the gastrocnemius medialis (GM) and lateralis (GL) muscles during submaximal plantarflexion depends on the orientation of the foot in the horizontal plane. The neural mechanisms behind these modulations are not known. The overall aim of this study was to determine whether the excitability of the two gastrocnemius muscles is differentially affected by changes in foot orientation. Nineteen males performed isometric plantarflexions with their foot internally (toes-in) or externally (toes-out) rotated. GM and GL motor unit discharge characteristics were estimated from high-density surface electromyography to estimate neural drive. GM and GL corticospinal excitability and intracortical activity were assessed using transcranial magnetic stimulation through motor-evoked potentials. The efficacy of synaptic transmission between Ia-afferent fibers and α-motoneurons of the GM and GL was evaluated through the Hoffmann reflex. We observed a differential change in neural drive between GM (toes-out > toes-in) and GL (toes-out < toes-in). However, there was no foot orientation-related modulation in corticospinal excitability of the GM or GL, either at the cortical level or through modulation of the efficacy of Ia-α-motoneuron transmission. These results demonstrate that change in the motor pathway excitability is not the mechanism controlling the different distribution of neural drive between GM and GL with foot orientation.NEW & NOTEWORTHY Horizontal foot orientation affects the distribution of neural drive between the gastrocnemii during plantarflexion. There is no foot orientation-related modulation in the corticospinal excitability of the gastrocnemii, either at the cortical level or through modulation of the efficacy of Ia-α-motoneuron transmission. Change in motor pathway excitability is not the mechanism controlling the different distribution of neural drive between gastrocnemius medialis and lateralis with foot orientation.
Collapse
Affiliation(s)
- Marion Crouzier
- Nantes University, Movement - Interactions - Performance, MIP, UR-4334, Nantes, France
| | - Simon Avrillon
- Department of Bioengineering, Faculty of Engineering, Imperial College London, London, United Kingdom
| | - François Hug
- Université Côte d'Azur, LAMHESS, Nice, France
- School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Thomas Cattagni
- Nantes University, Movement - Interactions - Performance, MIP, UR-4334, Nantes, France
| |
Collapse
|
5
|
Batzianouli ET, Caranzano L, Nguepnjo Nguissi NA, Miaz B, Herrmann FR, Benninger DH. The paired-pulse TMS paradigm of short intracortical inhibition is mediated by a reduction of repetitive motor neuron discharges. J Neurophysiol 2024; 131:541-547. [PMID: 38264793 DOI: 10.1152/jn.00346.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 01/19/2024] [Accepted: 01/21/2024] [Indexed: 01/25/2024] Open
Abstract
Transcranial magnetic stimulation (TMS) causes repetitive spinal motoneuron discharges (repMNDs), but the effects of short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) on repMNDs remain unknown. Triple stimulation technique (TST) and the extended TST-protocols that include a fourth and fifth stimulation, the Quadruple (QuadS) and Quintuple (QuintS) stimulation, respectively, offer a precise estimate of cortical and spinal motor neuron discharges, including repMNDs. The objective of our study was to explore the effects of SICI and ICF on repMNDs. We explored conventional paired-pulse TMS protocols of SICI and ICF with the TMS, TST, the QuadS, and the QuintS protocols, in a randomized study design in 20 healthy volunteers. We found significantly less repMNDs in the SICI paradigm compared with a single-pulse TMS (SP-TMS). No significant difference was observed in the ICF paradigm. There was a significant inter- and intrasubject variability in both SICI and ICF. We demonstrate a significant reduction of repMNDs in SICI, which may result from the suppression of later I-waves and mediate the inhibition of motor-evoked potential (MEP). There is no increase in repMNDs in ICF suggesting another mechanism underlying facilitation. This study provides the proof that a reduction of repMNDs mediates the inhibition seen in SICI.NEW & NOTEWORTHY Significant reduction of repetitive motor neuron discharges (repMNDs) in short-interval intracortical inhibition (SICI) may result from the suppression of later I-waves and mediate the inhibition of motor-evoked potential (MEP). There is no change in the number of repMNDs in intracortical facilitation (ICF). There was a significant variability in SICI and ICF in healthy subjects.
Collapse
Affiliation(s)
- Eleni T Batzianouli
- Neurology Service, Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
- Lemanic Neuroscience Doctoral School, Faculté de Biologie et de Médecine, Université de Lausanne, Lausanne, Switzerland
| | - Leonardo Caranzano
- Neurology Service, Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Nathalie A Nguepnjo Nguissi
- Neurology Service, Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Baptiste Miaz
- Neurology Service, Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - François R Herrmann
- Division of Geriatrics and rehabilitation, Department of Rehabilitation and Geriatrics, University Hospitals and University of Geneva, Geneva, Switzerland
| | - David H Benninger
- Neurology Service, Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| |
Collapse
|
6
|
Emanuele M, D'Ausilio A, Koch G, Fadiga L, Tomassini A. Scale-invariant changes in corticospinal excitability reflect multiplexed oscillations in the motor output. J Physiol 2024; 602:205-222. [PMID: 38059677 DOI: 10.1113/jp284273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 11/22/2023] [Indexed: 12/08/2023] Open
Abstract
In the absence of disease, humans produce smooth and accurate movement trajectories. Despite such 'macroscopic' aspect, the 'microscopic' structure of movements reveals recurrent (quasi-rhythmic) discontinuities. To date, it is unclear how the sensorimotor system contributes to the macroscopic and microscopic architecture of movement. Here, we investigated how corticospinal excitability changes in relation to microscopic fluctuations that are naturally embedded within larger macroscopic variations in motor output. Participants performed a visuomotor tracking task. In addition to the 0.25 Hz modulation that is required for task fulfilment (macroscopic scale), the motor output shows tiny but systematic fluctuations at ∼2 and 8 Hz (microscopic scales). We show that motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) during task performance are consistently modulated at all (time) scales. Surprisingly, MEP modulation covers a similar range at both micro- and macroscopic scales, even though the motor output differs by several orders of magnitude. Thus, corticospinal excitability finely maps the multiscale temporal patterning of the motor output, but it does so according to a principle of scale invariance. These results suggest that corticospinal excitability indexes a relatively abstract level of movement encoding that may reflect the hierarchical organisation of sensorimotor processes. KEY POINTS: Motor behaviour is organised on multiple (time)scales. Small but systematic ('microscopic') fluctuations are engrained in larger and slower ('macroscopic') variations in motor output, which are instrumental in deploying the desired motor plan. Corticospinal excitability is modulated in relation to motor fluctuations on both macroscopic and microscopic (time)scales. Corticospinal excitability obeys a principle of scale invariance, that is, it is modulated similarly at all (time)scales, possibly reflecting hierarchical mechanisms that optimise motor encoding.
Collapse
Affiliation(s)
- Marco Emanuele
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, Ferrara, Italy
- Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Ferrara, Italy
- Department of Computer Science, Western University, London, Ontario, Canada
| | - Alessandro D'Ausilio
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, Ferrara, Italy
- Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Ferrara, Italy
| | - Giacomo Koch
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, Ferrara, Italy
- IRCSS Santa Lucia, Roma, Italy
| | - Luciano Fadiga
- Department of Neuroscience and Rehabilitation, Section of Physiology, University of Ferrara, Ferrara, Italy
- Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Ferrara, Italy
| | - Alice Tomassini
- Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Ferrara, Italy
| |
Collapse
|
7
|
Rowe G, Allahham A, Edgar DW, Rurak BK, Fear MW, Wood FM, Vallence AM. Functional Brain Changes Following Burn Injury: A Narrative Review. Neurorehabil Neural Repair 2024; 38:62-72. [PMID: 38044625 PMCID: PMC10798013 DOI: 10.1177/15459683231215331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
BACKGROUND Burn injuries cause significant motor and sensory dysfunctions that can negatively impact burn survivors' quality of life. The underlying mechanisms of these burn-induced dysfunctions have primarily been associated with damage to the peripheral neural architecture, however, evidence points to a systemic influence of burn injury. Central nervous system (CNS) reorganizations due to inflammation, afferent dysfunction, and pain could contribute to persistent motor and sensory dysfunction in burn survivors. Recent evidence shows that the capacity for neuroplasticity is associated with self-reported functional recovery in burn survivors. OBJECTIVE This review first outlines motor and sensory dysfunctions following burn injury and critically examines recent literature investigating the mechanisms mediating CNS reorganization following burn injury. The review then provides recommendations for future research and interventions targeting the CNS such as non-invasive brain stimulation to improve functional recovery. CONCLUSIONS Directing focus to the CNS following burn injury, alongside the development of non-invasive methods to induce functionally beneficial neuroplasticity in the CNS, could advance treatments and transform clinical practice to improve quality of life in burn survivors.
Collapse
Affiliation(s)
- Grant Rowe
- School of Psychology, College of Health and Education, Murdoch University, Murdoch, WA, Australia
| | - Amira Allahham
- Burn Injury Research Unit, School of Biomedical Sciences, University of Western Australia, Crawley, WA, Australia
| | - Dale W. Edgar
- Fiona Wood Foundation, Murdoch, WA, Australia
- Burn Service of Western Australia, Fiona Stanley Hospital, MNH (B) Main Hospital, Level 4, Burns Unit, Murdoch, WA, Australia
- Institute for Health Research, The University of Notre Dame Australia, Fremantle, WA, Australia
| | - Brittany K. Rurak
- School of Psychology, College of Health and Education, Murdoch University, Murdoch, WA, Australia
| | - Mark W. Fear
- Burn Injury Research Unit, School of Biomedical Sciences, University of Western Australia, Crawley, WA, Australia
- Fiona Wood Foundation, Murdoch, WA, Australia
| | - Fiona M. Wood
- Burn Injury Research Unit, School of Biomedical Sciences, University of Western Australia, Crawley, WA, Australia
- Fiona Wood Foundation, Murdoch, WA, Australia
- Burn Service of Western Australia, Fiona Stanley Hospital, MNH (B) Main Hospital, Level 4, Burns Unit, Murdoch, WA, Australia
| | - Ann-Maree Vallence
- School of Psychology, College of Health and Education, Murdoch University, Murdoch, WA, Australia
- Centre for Healthy Ageing, Health Futures Institute, Murdoch University, Murdoch, WA, Australia
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, Australia
| |
Collapse
|
8
|
Bai Z, Zhu F, Lou X, Zhang JJ, Jin M, Qin W, Tang C, Li J, Lu J, Lin J, Jin L, Qi Q, Fong KNK. Considerable effects of lateralization and aging in intracortical excitation and inhibition. Front Neurosci 2023; 17:1269474. [PMID: 38033537 PMCID: PMC10687141 DOI: 10.3389/fnins.2023.1269474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 10/30/2023] [Indexed: 12/02/2023] Open
Abstract
Introduction Findings based on the use of transcranial magnetic stimulation and electromyography (TMS-EMG) to determine the effects of motor lateralization and aging on intracortical excitation and inhibition in the primary motor cortex (M1) are inconsistent in the literature. TMS and electroencephalography (TMS-EEG) measures the excitability of excitatory and inhibitory circuits in the brain cortex without contamination from the spine and muscles. This study aimed to investigate the effects of motor lateralization (dominant and non-dominant hemispheres) and aging (young and older) and their interaction effects on intracortical excitation and inhibition within the M1 in healthy adults, measured using TMS-EMG and TMS-EEG. Methods This study included 21 young (mean age = 28.1 ± 3.2 years) and 21 older healthy adults (mean age = 62.8 ± 4.2 years). A battery of TMS-EMG measurements and single-pulse TMS-EEG were recorded for the bilateral M1. Results Two-way repeated-measures analysis of variance was used to investigate lateralization and aging and the lateralization-by-aging interaction effect on neurophysiological outcomes. The non-dominant M1 presented a longer cortical silent period and larger amplitudes of P60, N100, and P180. Corticospinal excitability in older participants was significantly reduced, as supported by a larger resting motor threshold and lower motor-evoked potential amplitudes. N100 amplitudes were significantly reduced in older participants, and the N100 and P180 latencies were significantly later than those in young participants. There was no significant lateralization-by-aging interaction effect in any outcome. Conclusion Lateralization and aging have independent and significant effects on intracortical excitation and inhibition in healthy adults. The functional decline of excitatory and inhibitory circuits in the M1 is associated with aging.
Collapse
Affiliation(s)
- Zhongfei Bai
- Department of Rehabilitation, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Centre), School of Medicine, Tongji University, Shanghai, China
| | - Feifei Zhu
- Department of Rehabilitation, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Centre), School of Medicine, Tongji University, Shanghai, China
| | - Xiaoyu Lou
- Department of Rehabilitation, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Centre), School of Medicine, Tongji University, Shanghai, China
| | - Jack Jiaqi Zhang
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Minxia Jin
- Department of Rehabilitation, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Centre), School of Medicine, Tongji University, Shanghai, China
| | - Wenting Qin
- Department of Rehabilitation, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Centre), School of Medicine, Tongji University, Shanghai, China
| | - Chaozheng Tang
- Capacity Building and Continuing Education Center, National Health Commission of the People's Republic of China, Beijing, China
| | - Jie Li
- School of Electronic and Information Engineering, Tongji University, Shanghai, China
| | - Jiani Lu
- Department of Rehabilitation, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Centre), School of Medicine, Tongji University, Shanghai, China
| | - Jianhua Lin
- Department of Rehabilitation, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Centre), School of Medicine, Tongji University, Shanghai, China
| | - Lingjing Jin
- Department of Rehabilitation, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Centre), School of Medicine, Tongji University, Shanghai, China
| | - Qi Qi
- Department of Rehabilitation, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Centre), School of Medicine, Tongji University, Shanghai, China
| | - Kenneth N. K. Fong
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| |
Collapse
|
9
|
Amerio A, Baccino C, Breda GS, Cortesi D, Spiezio V, Magnani L, De Berardis D, Conio B, Costanza A, De Paola G, Rocca G, Arduino G, Aguglia A, Amore M, Serafini G. Effects of transcranial magnetic stimulation on cocaine addiction: A systematic review of randomized controlled trials. Psychiatry Res 2023; 329:115491. [PMID: 37783092 DOI: 10.1016/j.psychres.2023.115491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 09/17/2023] [Accepted: 09/21/2023] [Indexed: 10/04/2023]
Abstract
OBJECTIVE While pharmacological strategies appear to be ineffective in treating long-term addiction, repetitive transcranial magnetic stimulation (rTMS) is emerging as a promising new tool for the attenuation of craving among multiple substance dependent populations. METHOD A systematic review of randomized controlled trials (RCTs) was conducted on the efficacy and tolerability of rTMS in treating cocaine use disorder (CUD). Relevant papers published in English through November 30th 2022 were identified, searching the electronic databases MEDLINE, Embase, PsycINFO and the Cochrane Library. RESULTS Eight studies matched inclusion criteria. The best findings were reported by the RCTs conducted at high-frequency (≥5 Hz) multiple sessions of rTMS delivered over the left dorsolateral prefrontal cortex (DLPFC): a significant decrease in self-reported cue-induced cocaine craving and lower cocaine craving scores and a considerable amelioration in the tendency to act rashly under extreme negative emotions (impulsivity) were found in the active group compared to controls. CONCLUSION Although still scant and heterogeneous, the strongest evidence so far on the use of rTMS on individuals with CUD support the high frequency stimulation over the left DLPFC as a well tolerated treatment of cocaine craving and impulsivity.
Collapse
Affiliation(s)
- A Amerio
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), Section of Psychiatry, University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
| | - C Baccino
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), Section of Psychiatry, University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - G S Breda
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), Section of Psychiatry, University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - D Cortesi
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), Section of Psychiatry, University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
| | - V Spiezio
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), Section of Psychiatry, University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - L Magnani
- Department of Psychiatry, San Maurizio Hospital, Bolzano, Italy
| | - D De Berardis
- NHS, Department of Mental Health, Psychiatric Service for Diagnosis and Treatment, Hospital "G. Mazzini", ASL 4, Teramo, Italy.
| | - B Conio
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - A Costanza
- Department of Psychiatry, Faculty of Medicine, Geneva University (UNIGE), Geneva, Switzerland; Department of Psychiatry, Adult Psychiatry Service (SPA), University Hospitals of Geneva (HUG), Geneva, Switzerland; Department of Psychiatry, Faculty of Biomedical Sciences, University of Italian Switzerland (USI), Lugano, Switzerland.
| | - G De Paola
- Ospedale Maria Luigia, Monticelli Terme, Italy
| | - G Rocca
- R&R Neuromodulation Lab, Piacenza, Italy
| | - G Arduino
- Department of Mental Health and Pathological Addictions, Piacenza Local Health Authority, Piacenza, Italy
| | - A Aguglia
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), Section of Psychiatry, University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
| | - M Amore
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), Section of Psychiatry, University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
| | - G Serafini
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), Section of Psychiatry, University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
| |
Collapse
|
10
|
Aberra AS, Lopez A, Grill WM, Peterchev AV. Rapid estimation of cortical neuron activation thresholds by transcranial magnetic stimulation using convolutional neural networks. Neuroimage 2023; 275:120184. [PMID: 37230204 PMCID: PMC10281353 DOI: 10.1016/j.neuroimage.2023.120184] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 04/13/2023] [Accepted: 05/22/2023] [Indexed: 05/27/2023] Open
Abstract
BACKGROUND Transcranial magnetic stimulation (TMS) can modulate neural activity by evoking action potentials in cortical neurons. TMS neural activation can be predicted by coupling subject-specific head models of the TMS-induced electric field (E-field) to populations of biophysically realistic neuron models; however, the significant computational cost associated with these models limits their utility and eventual translation to clinically relevant applications. OBJECTIVE To develop computationally efficient estimators of the activation thresholds of multi-compartmental cortical neuron models in response to TMS-induced E-field distributions. METHODS Multi-scale models combining anatomically accurate finite element method (FEM) simulations of the TMS E-field with layer-specific representations of cortical neurons were used to generate a large dataset of activation thresholds. 3D convolutional neural networks (CNNs) were trained on these data to predict thresholds of model neurons given their local E-field distribution. The CNN estimator was compared to an approach using the uniform E-field approximation to estimate thresholds in the non-uniform TMS-induced E-field. RESULTS The 3D CNNs estimated thresholds with mean absolute percent error (MAPE) on the test dataset below 2.5% and strong correlation between the CNN predicted and actual thresholds for all cell types (R2 > 0.96). The CNNs estimated thresholds with a 2-4 orders of magnitude reduction in the computational cost of the multi-compartmental neuron models. The CNNs were also trained to predict the median threshold of populations of neurons, speeding up computation further. CONCLUSION 3D CNNs can estimate rapidly and accurately the TMS activation thresholds of biophysically realistic neuron models using sparse samples of the local E-field, enabling simulating responses of large neuron populations or parameter space exploration on a personal computer.
Collapse
Affiliation(s)
- Aman S Aberra
- Department of Biomedical Engineering, School of Engineering, Duke University, NC, USA
| | - Adrian Lopez
- Department of Electrical and Computer Engineering, School of Engineering, Duke University, NC, USA; Department of Mathematics, College of Arts and Sciences, Duke University, NC, USA
| | - Warren M Grill
- Department of Biomedical Engineering, School of Engineering, Duke University, NC, USA; Department of Electrical and Computer Engineering, School of Engineering, Duke University, NC, USA; Department of Neurobiology, School of Medicine, Duke University, NC, USA; Department of Neurosurgery, School of Medicine, Duke University, NC, USA
| | - Angel V Peterchev
- Department of Biomedical Engineering, School of Engineering, Duke University, NC, USA; Department of Electrical and Computer Engineering, School of Engineering, Duke University, NC, USA; Department of Neurosurgery, School of Medicine, Duke University, NC, USA; Department of Psychiatry and Behavioral Sciences, School of Medicine, Duke University, NC, USA.
| |
Collapse
|
11
|
Dempsey LM, Kavanagh JJ. Muscarinic acetylcholine activity modulates cortical silent period, but not motor evoked potentials, during muscle contractions. Exp Brain Res 2023; 241:1543-1553. [PMID: 37103494 DOI: 10.1007/s00221-023-06616-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 04/11/2023] [Indexed: 04/28/2023]
Abstract
This study used transcranial magnetic stimulation (TMS) to determine if muscarinic receptor blockade affects muscle responses during voluntary contractions. Motor evoked potentials (MEPs) were recorded from biceps brachii in 10 subjects (age: 23 ± 2) during 10%, 25%, 50%, 75%, and 100% maximal voluntary contractions (MVCs). Each contraction intensity was examined under non-fatigued and fatigued conditions. All measurements were obtained post-ingestion of 25 mg promethazine or placebo. MEP area and the duration of the TMS-evoked silent period (SP) were calculated for all contractions. No drug-related differences were detected for MEP area during non-fatigued or fatigued contractions. A main effect of drug was detected for the SP (p = 0.019) where promethazine increased SP duration by an average of 0.023 [Formula: see text] 0.015 s. This drug effect was only identified for the unfatigued contractions and not following the sustained fatiguing contractions (p = 0.105). The cholinergic system does not influence corticospinal excitability during voluntary muscle contractions, but instead affects neural circuits associated with the TMS-evoked SP. Given the prevalence of cholinergic properties in prescription and over-the-counter medications, the current study enhances our understanding of mechanisms that may contribute to motor side-effects.
Collapse
Affiliation(s)
- Lisa M Dempsey
- Menzies Health Institute Queensland, Griffith University, Southport, Australia.
- School of Allied Health Sciences, Griffith University, Gold Coast Campus, Southport, QLD, 4222, Australia.
| | - Justin J Kavanagh
- Menzies Health Institute Queensland, Griffith University, Southport, Australia
| |
Collapse
|
12
|
Pavey N, Menon P, van den Bos MAJ, Kiernan MC, Vucic S. Cortical inhibition and facilitation are mediated by distinct physiological processes. Neurosci Lett 2023; 803:137191. [PMID: 36924929 DOI: 10.1016/j.neulet.2023.137191] [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: 11/30/2022] [Revised: 03/01/2023] [Accepted: 03/11/2023] [Indexed: 03/17/2023]
Abstract
A complex interaction of inhibitory and facilitatory interneuronal processes may underlie development of cortical excitability in the human motor cortex. To determine whether distinct interneuronal processes mediated cortical excitability, threshold tracking transcranial magnetic stimulation was utilised to assess cortical excitability, with figure-of-eight coil oriented in posterior-anterior (PA), anterior-posterior (AP) and latero-medial (LM) directions. Motor evoked potential (MEP) responses were recorded over the contralateral abductor pollicis brevis. Resting motor threshold (RMT), short interval intracortical inhibition (SICI), short interval intracortical facilitation (SICF) and intracortical facilitation were recorded. Significant effects of coil orientation were evident on SICI (F = 8.560, P = 0.002) and SICF (F = 7.132, P = 0.003). SICI was greater when recorded with PA (9.7 ± 10.9%, P = 0.029) and AP (13.1 ± 7.0%, P = 0.003) compared to LM (5.2 ± 7.3%) directed currents. SICF was significantly greater with PA (-14.7 ± 8.1%, P = 0.016) and LM (-14.7 ± 8.8%, P = 0.005) compared to AP (-9.1 ± 7.2%) coil orientations. SICI recorded with LM and PA coil orientations were correlated (R = 0.7, P = 0.002), as was SICF recorded with AP vs LM (R = 0.60, P = 0.019) and LM vs PA (R = 0.69, P = 0.002) coil orientations. RMT was significantly smaller with PA compared to AP (P < 0.001) and LM (P = 0.018) stimulation. Recruitment of distinct interneuronal processes with variable cortical orientation and thresholds underlies short interval intracortical inhibition and facilitation.
Collapse
Affiliation(s)
- Nathan Pavey
- Brain and Nerve Research Centre, Concord Clinical School, University of Sydney, Concord Hospital, Sydney, NSW, Australia
| | - Parvathi Menon
- Brain and Nerve Research Centre, Concord Clinical School, University of Sydney, Concord Hospital, Sydney, NSW, Australia
| | - Mehdi A J van den Bos
- Brain and Nerve Research Centre, Concord Clinical School, University of Sydney, Concord Hospital, Sydney, NSW, Australia
| | | | - Steve Vucic
- Brain and Nerve Research Centre, Concord Clinical School, University of Sydney, Concord Hospital, Sydney, NSW, Australia.
| |
Collapse
|
13
|
Therrien-Blanchet JM, Ferland MC, Badri M, Rousseau MA, Merabtine A, Boucher E, Hofmann LH, Lepage JF, Théoret H. The neurophysiological aftereffects of brain stimulation in human primary motor cortex: a Sham-controlled comparison of three protocols. Cereb Cortex 2023:7030623. [PMID: 36749004 DOI: 10.1093/cercor/bhad021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 01/14/2023] [Accepted: 01/15/2023] [Indexed: 02/08/2023] Open
Abstract
Paired associative stimulation (PAS), transcranial direct current stimulation (tDCS), and transcranial alternating current stimulation (tACS) are non-invasive brain stimulation methods that are used to modulate cortical excitability. Whether one technique is superior to the others in achieving this outcome and whether individuals that respond to one intervention are more likely to respond to another remains largely unknown. In the present study, the neurophysiological aftereffects of three excitatory neurostimulation protocols were measured with transcranial magnetic stimulation (TMS). Twenty minutes of PAS at an ISI of 25 ms, anodal tDCS, 20-Hz tACS, and Sham stimulation were administered to 31 healthy adults in a repeated measures design. Compared with Sham, none of the stimulation protocols significantly modulated corticospinal excitability (input/ouput curve and slope, TMS stimulator intensity required to elicit MEPs of 1-mV amplitude) or intracortical excitability (short- and long-interval intracortical inhibition, intracortical facilitation, cortical silent period). Sham-corrected responder analysis estimates showed that an average of 41 (PAS), 39 (tDCS), and 39% (tACS) of participants responded to the interventions with an increase in corticospinal excitability. The present data show that three stimulation protocols believed to increase cortical excitability are associated with highly heterogenous and variable aftereffects that may explain a lack of significant group effects.
Collapse
Affiliation(s)
| | | | - Meriem Badri
- Département de psychologie, Université de Montréal, Montréal, QC H3C 3J7, Canada
| | | | - Amira Merabtine
- Département de psychologie, Université de Montréal, Montréal, QC H3C 3J7, Canada
| | - Emelie Boucher
- Département de psychologie, Université de Montréal, Montréal, QC H3C 3J7, Canada
| | - Lydia Helena Hofmann
- Department of Psychology and Neuroscience, Maastricht University, Maastricht 6229, The Netherlands
| | - Jean-François Lepage
- Département de Pédiatrie, Faculté de Médecine et des Sciences de la Santé de l'Université de Sherbrooke, Centre de Recherche du CHU Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Hugo Théoret
- Département de psychologie, Université de Montréal, Montréal, QC H3C 3J7, Canada
| |
Collapse
|
14
|
Murgaš M, Unterholzner J, Stöhrmann P, Philippe C, Godbersen GM, Nics L, Reed MB, Vraka C, Vanicek T, Wadsak W, Kranz GS, Hahn A, Mitterhauser M, Hacker M, Kasper S, Lanzenberger R, Baldinger-Melich P. Effects of bilateral sequential theta-burst stimulation on 5-HT 1A receptors in the dorsolateral prefrontal cortex in treatment-resistant depression: a proof-of-concept trial. Transl Psychiatry 2023; 13:33. [PMID: 36725835 PMCID: PMC9892572 DOI: 10.1038/s41398-023-02319-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 01/09/2023] [Accepted: 01/12/2023] [Indexed: 02/03/2023] Open
Abstract
Theta-burst stimulation (TBS) represents a brain stimulation technique effective for treatment-resistant depression (TRD) as underlined by meta-analyses. While the methodology undergoes constant refinement, bilateral stimulation of the dorsolateral prefrontal cortex (DLPFC) appears promising to restore left DLPFC hypoactivity and right hyperactivity found in depression. The post-synaptic inhibitory serotonin-1A (5-HT1A) receptor, also occurring in the DLPFC, might be involved in this mechanism of action. To test this hypothesis, we performed PET-imaging using the tracer [carbonyl-11C]WAY-100635 including arterial blood sampling before and after a three-week treatment with TBS in 11 TRD patients compared to sham stimulation (n = 8 and n = 3, respectively). Treatment groups were randomly assigned, and TBS protocol consisted of excitatory intermittent TBS to the left and inhibitory continuous TBS to the right DLPFC. A linear mixed model including group, hemisphere, time, and Hamilton Rating Scale for Depression (HAMD) score revealed a 3-way interaction effect of group, time, and HAMD on specific distribution volume (VS) of 5-HT1A receptor. While post-hoc comparisons showed no significant changes of 5-HT1A receptor VS in either group, higher 5-HT1A receptor VS after treatment correlated with greater difference in HAMD (r = -0.62). The results of this proof-of-concept trial hint towards potential effects of TBS on the distribution of the 5-HT1A receptor. Due to the small sample size, all results must, however, be regarded with caution.
Collapse
Affiliation(s)
- Matej Murgaš
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Jakob Unterholzner
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Peter Stöhrmann
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Cécile Philippe
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Godber M Godbersen
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Lukas Nics
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Murray B Reed
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Chrysoula Vraka
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Thomas Vanicek
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Wadsak
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Georg S Kranz
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Andreas Hahn
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Markus Mitterhauser
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
- Ludwig Boltzmann Institute Applied Diagnostics, Vienna, Austria
- Department of Chemistry, Institute of Inorganic Chemistry, University of Vienna, Vienna, Austria
| | - Marcus Hacker
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Siegfried Kasper
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria.
| | - Rupert Lanzenberger
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria.
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria.
| | - Pia Baldinger-Melich
- Department of Psychiatry and Psychotherapy, Clinical Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
15
|
Zrenner C, Kozák G, Schaworonkow N, Metsomaa J, Baur D, Vetter D, Blumberger DM, Ziemann U, Belardinelli P. Corticospinal excitability is highest at the early rising phase of sensorimotor µ-rhythm. Neuroimage 2023; 266:119805. [PMID: 36513289 DOI: 10.1016/j.neuroimage.2022.119805] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 11/30/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022] Open
Abstract
Alpha oscillations are thought to reflect alternating cortical states of excitation and inhibition. Studies of perceptual thresholds and evoked potentials have shown the scalp EEG negative phase of the oscillation to correspond to a short-lasting low-threshold and high-excitability state of underlying visual, somatosensory, and primary motor cortex. The negative peak of the oscillation is assumed to correspond to the state of highest excitability based on biophysical considerations and considerable effort has been made to improve the extraction of a predictive signal by individually optimizing EEG montages. Here, we investigate whether it is the negative peak of sensorimotor µ-rhythm that corresponds to the highest corticospinal excitability, and whether this is consistent between individuals. In 52 adult participants, a standard 5-channel surface Laplacian EEG montage was used to extract sensorimotor µ-rhythm during transcranial magnetic stimulation (TMS) of primary motor cortex. Post-hoc trials were sorted from 800 TMS-evoked motor potentials (MEPs) according to the pre-stimulus EEG (estimated instantaneous phase) and MEP amplitude (as an index of corticospinal excitability). Different preprocessing transformations designed to improve the accuracy by which µ-alpha phase predicts excitability were also tested. By fitting a sinusoid to the MEP amplitudes, sorted according to pre-stimulus EEG-phase, we found that excitability was highest during the early rising phase, at a significant delay with respect to the negative peak by on average 45° or 10 ms. The individual phase of highest excitability was consistent across study participants and unaffected by two different EEG-cleaning methods that utilize 64 channels to improve signal quality by compensating for individual noise level and channel covariance. Personalized transformations of the montage did not yield better prediction of excitability from µ-alpha phase. The relationship between instantaneous phase of a brain oscillation and fluctuating cortical excitability appears to be more complex than previously hypothesized. In TMS of motor cortex, a standard surface Laplacian 5-channel EEG montage is effective in extracting a predictive signal and the phase corresponding to the highest excitability appears to be consistent between individuals. This is an encouraging result with respect to the clinical potential of therapeutic personalized brain interventions in the motor system. However, it remains to be investigated, whether similar results can be obtained for other brain areas and brain oscillations targeted with EEG and TMS.
Collapse
Affiliation(s)
- Christoph Zrenner
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada; Institute for Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Department of Neurology & Stroke, University of Tübingen, Germany.
| | - Gábor Kozák
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie Institute for Clinical Brain Research, University of Tübingen, Germany
| | - Natalie Schaworonkow
- Ernst Strüngmann Institute for Neuroscience in Cooperation with Max Planck Society, Frankfurt am Main, Germany
| | - Johanna Metsomaa
- Department of Neurology & Stroke, University of Tübingen, Germany; Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
| | - David Baur
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie Institute for Clinical Brain Research, University of Tübingen, Germany
| | - David Vetter
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie Institute for Clinical Brain Research, University of Tübingen, Germany
| | - Daniel M Blumberger
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Ulf Ziemann
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie Institute for Clinical Brain Research, University of Tübingen, Germany.
| | - Paolo Belardinelli
- Department of Neurology & Stroke, University of Tübingen, Germany; CIMeC, Center for Mind/Brain Sciences, University of Trento, Trento, Italy
| |
Collapse
|
16
|
Kesselheim J, Takemi M, Christiansen L, Karabanov AN, Siebner HR. Multipulse transcranial magnetic stimulation of human motor cortex produces short-latency corticomotor facilitation via two distinct mechanisms. J Neurophysiol 2023; 129:410-420. [PMID: 36629338 DOI: 10.1152/jn.00263.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Single-pulse transcranial magnetic stimulation (TMS) of the precentral hand representation (M1HAND) can elicit indirect waves in the corticospinal tract at a periodicity of ∼660 Hz, called I-waves. These descending volleys are produced by transsynaptic excitation of fast-conducting corticospinal axons in M1HAND. Paired-pulse TMS can induce short-interval intracortical facilitation (SICF) of motor evoked potentials (MEPs) at interpulse intervals that match I-wave periodicity. This study examined whether short-latency corticospinal facilitation engages additional mechanisms independently of I-wave periodicity. In 19 volunteers, one to four biphasic TMS pulses were applied to left M1HAND with interpulse intervals adjusted to the first peak or trough of the individual SICF curve at different intensities to probe the intensity-response relationship. Multipulse TMSHAND at individual peak latency facilitated MEP amplitudes and reduced resting motor threshold (RMT) compared with single pulses. Multipulse TMSHAND at individual trough latency also produced a consistent facilitation of MEPs and a reduction of RMT. Short-latency facilitation at trough latency was less pronounced, but the relative difference in facilitation decreased with increasing stimulus intensity. Increasing the pulse number had only a modest effect. Two mechanisms underlie short-latency facilitation caused by biphasic multipulse TMSHAND. One intracortical mechanism is related to I-wave periodicity and engages fast-conducting direct projections to spinal motoneurons. A second corticospinal mechanism does not rely on I-wave rhythmicity and may be mediated by slower-conducting indirect pyramidal tract projections from M1HAND to spinal interneurons. The latter mechanism deserves more attention in studies of the corticomotor system and its link to manual motor control using the MEP.NEW & NOTEWORTHY TMS pairs evoke SICF at interpulse intervals (IPIs) that match I-wave periodicity. Biphasic bursts with IPIs at the latency of the first peak facilitate MEPs and reduce corticomotor threshold. Bursts at the latency of the first trough facilitate MEPs and reduce corticomotor threshold to a lesser extent. TMS bursts facilitate corticomotor excitability via two mechanisms: SICF-dependently via fast-conducting direct projections from M1HAND to spinal motoneurons and SICF-independently, probably through slower-conducting indirect pyramidal tract projections.
Collapse
Affiliation(s)
- Janine Kesselheim
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark
| | - Mitsuaki Takemi
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark.,Division of Physical and Health Education, Graduate School of Education, The University of Tokyo, Bunkyo City, Tokyo, Japan
| | - Lasse Christiansen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark
| | - Anke Ninija Karabanov
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark.,Section for Integrative Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark.,Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen NV, Denmark.,Institute for Clinical Medicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen N, Denmark
| |
Collapse
|
17
|
Volberg C, Wulf H, Schubert AK. [Pain Management in Palliative Care]. Anasthesiol Intensivmed Notfallmed Schmerzther 2023; 58:95-110. [PMID: 36791774 DOI: 10.1055/a-1962-6298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Patients in the palliative phase of a disease often suffer from pain, which leads to a significant reduction in quality of life. Since in most cases there is a progression rather than an improvement of the disease over time, pain therapy must also be dynamically adapted. Due to accompanying symptoms and the physical burden of the disease, treatment of pain is often difficult. In the palliative situation, pain should not only be understood as an excitation of nociceptors but is rather also an expression of mental stress. In this article, we would like to give an overview of the available drugs, application methods and alternative treatment options. Specifically, the article is divided into the following subsections: non-opioid analgesics, opioids, co-analgesics, patient-controlled analgesia procedures, neuraxial and peripheral regional anesthesia procedures, neurolysis, supportive therapies and palliative sedation. Thus, when treating palliative patients, the focus should not only be on the one symptom of pain, but, in the sense of the bio-psycho-social model, a multimodal oriented treatment of the patient with all his symptoms, also including his relatives, must be carried out.
Collapse
|
18
|
Wooliscroft L, McCoy S, Hildebrand A, Rooney W, Oken BS, Spain RI, Kuehl KS, Bourdette D, Cameron M. Protocol for an exploratory, randomised, single-blind clinical trial of aerobic exercise to promote remyelination in multiple sclerosis. BMJ Open 2023; 13:e061539. [PMID: 36596632 PMCID: PMC9814998 DOI: 10.1136/bmjopen-2022-061539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
INTRODUCTION There is an urgent need for remyelinating therapies that restore function in people with multiple sclerosis (pwMS). Aerobic exercise is a promising remyelinating strategy because it promotes remyelination in animal models both independently and synergistically with medications. Here, in this study, we present an innovative, randomised, single-blind, clinical trial designed to explore: the relationship between demyelination and mobility (part 1), and if 24 weeks of aerobic exercise promotes remyelination in pwMS (part 2). METHODS AND ANALYSIS Sedentary participants (n=60; aged 18-64 years) with stable MS will undergo a baseline visit with the following outcomes to assess associations between demyelination and mobility (part 1): spinal cord demyelination (somatosensory-evoked potentials, SSEPs), mobility (6-Minute Timed Walk, Timed 25-Foot Walk, Timed Up and Go, 9-Hole Peg Test) and patient-reported outcomes (PROs). After baseline testing, participants with significantly prolonged SSEP latency will advance to the clinical exercise trial (part 2) and will be randomised 1:1 to active or control conditions for 24 weeks. The active condition will be aerobic stationary cycling three times per week with graded virtual supervision. The control condition will be monthly virtual MS symptom education groups (six sessions). SSEP latency (remyelination endpoint), mobility outcomes and PROs will be measured at 12 and 24 weeks in all clinical trial participants. A subset of 11 active and 11 control participants will undergo a brain MRI with quantitative T1 myelin water fraction at baseline and 24 weeks (exploratory remyelination endpoint). ETHICS AND DISSEMINATION Ethical approval was obtained from the Oregon Health & Science University Institutional Review Board (#21045). Dissemination of findings will include peer-reviewed publications, conference presentations and media releases. The proposed study will inform the feasibility, study design and sample size for a fully powered clinical trial of aerobic exercise to promote remyelination in pwMS. TRIAL REGISTRATION NUMBER NCT04539002.
Collapse
Affiliation(s)
- Lindsey Wooliscroft
- Neurology, Oregon Health & Science University, Portland, Oregon, USA
- Neurology, Portland VA Medical Center, Portland, Oregon, USA
| | - Sharon McCoy
- Neurology, Oregon Health & Science University, Portland, Oregon, USA
| | - Andrea Hildebrand
- Biostatistics and Design Program Core, Oregon Health & Science University, Portland, Oregon, USA
| | - William Rooney
- Advanced Imaging Research Center, Oregon Health & Science University, Portland, Oregon, USA
| | - Barry S Oken
- Neurology, Oregon Health & Science University, Portland, Oregon, USA
| | - Rebecca Irene Spain
- Neurology, Oregon Health & Science University, Portland, Oregon, USA
- Neurology, Portland VA Medical Center, Portland, Oregon, USA
| | - Kerry S Kuehl
- School of Medicine, Oregon Health & Science University, Portland, Oregon, USA
| | - Dennis Bourdette
- Neurology, Oregon Health & Science University, Portland, Oregon, USA
| | - Michelle Cameron
- Neurology, Oregon Health & Science University, Portland, Oregon, USA
- Neurology, Portland VA Medical Center, Portland, Oregon, USA
| |
Collapse
|
19
|
Stability and test-retest reliability of neuronavigated TMS measures of corticospinal and intracortical excitability. Brain Res 2022; 1794:148057. [PMID: 35987284 DOI: 10.1016/j.brainres.2022.148057] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 07/08/2022] [Accepted: 08/15/2022] [Indexed: 11/22/2022]
Abstract
The present study aimed at investigating the long-term stability and test-retest reliability of neuronavigated transcranial magnetic stimulation (nTMS) measures of cortical excitability, inhibition, and facilitation in the primary motor cortex. To fulfill these aims, thirty-one healthy adults underwent four nTMS sessions, over an average one-month period. Stability and test-retest reliability statistics were computed and analyzed to produce smallest real difference statistics, which indicate the absolute variation in a measurement that is likely to be the result of error (randomness). Excellent reliability was found for resting motor thresholds, which reflect baseline neuronal excitability. Good reliability statistics were found for input/output curve measurements, which reflect the excitability of a highly plastic neuronal population. Using the slope of mean amplitudes throughout the input/output curve or the stimulator intensity required to elicit motor evoked potentials of 1 mV presented good to excellent measurement reliability for global cortical excitability indexing, compared to mean MEP at a given intensity. Overall, this methodological study provides useful and novel information on transcranial magnetic stimulation interventions by providing smallest real difference statistics that inform on potential response thresholds across time, contributing to the validation of these measurements as clinical monitoring tools across time.
Collapse
|
20
|
Effects of stimulus waveform on transcranial magnetic stimulation metrics in proximal and distal arm muscles. Neurophysiol Clin 2022; 52:366-374. [PMID: 35906169 DOI: 10.1016/j.neucli.2022.07.002] [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: 09/28/2021] [Revised: 07/06/2022] [Accepted: 07/06/2022] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES The purpose of this study was to determine the effect of common transcranial magnetic stimulation (TMS) waveforms (monophasic and biphasic) on resting motor threshold (RMT), active motor threshold (AMT), and motor evoked potential (MEP) amplitudes in the biceps and first dorsal interosseous (FDI) because waveforms may affect motor targets differently. We also determined test-retest reliability. METHODS Ten individuals participated in two sessions of TMS delivered to the motor cortex. Monophasic stimulation to induce a posterior-anterior current in the brain (monoPA) and biphasic posterior-anterior then anterior-posterior (biPA-AP) were applied in each session in random order. In each session, there were four blocks of measurements (2 muscles × 2 waveforms) of RMT, AMT and MEPs at the hotspot location. MEPs were normalized to the maximum EMG signal. RESULTS RMTs and AMTs were lower for monoPA compared to biPA-AP stimulation for the biceps (p<0.01) and FDI (p<0.01). Normalized MEPs were greater for monoPA compared to biPA-AP stimulation in the FDI (p=0.01) and not different in the biceps (p=0.86). Motor thresholds were not different between sessions suggesting high reliability (p<0.01). Normalized MEPs had very low reliability across sessions in the FDI, and moderate reliability in the biceps. DISCUSSION Preliminary investigation suggests the effect of TMS waveform on motor thresholds is similar in upper limb proximal and distal muscles, but the effect differs per motor target for MEPs. Further, test-retest reliability of waveform effects was sensitive to target muscle. These findings may contribute to improve the efficacy and reliability of TMS for clinical use.
Collapse
|
21
|
Zrenner C, Belardinelli P, Ermolova M, Gordon PC, Stenroos M, Zrenner B, Ziemann U. µ-rhythm phase from somatosensory but not motor cortex correlates with corticospinal excitability in EEG-triggered TMS. J Neurosci Methods 2022; 379:109662. [PMID: 35803405 DOI: 10.1016/j.jneumeth.2022.109662] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 05/18/2022] [Accepted: 07/04/2022] [Indexed: 10/17/2022]
Abstract
BACKGROUND Sensorimotor µ-rhythm phase is correlated with corticospinal excitability. Transcranial magnetic stimulation (TMS) of motor cortex results in larger motor evoked potentials (MEPs) during the negative peak of the EEG oscillation as extracted with a surface Laplacian. However, the anatomical source of the relevant oscillation is not clear and demonstration of the relationship is sensitive to the choice of EEG montage. OBJECTIVE/HYPOTHESIS Here, we compared two EEG montages preferentially sensitive to oscillations originating from the crown of precentral gyrus (dorsal premotor cortex) vs. postcentral gyrus (secondary somatosensory cortex). We hypothesized that the EEG signal from precentral gyrus would correlate more strongly with MEP amplitude, given that the corticospinal neurons are located in the anterior wall of the sulcus and the corticospinal tract has input from premotor cortex. NEW METHOD Real-time EEG-triggered TMS of motor cortex was applied in 6 different conditions in randomly interleaved order, 3 phase conditions (positive peak, negative peak, random phase of the ongoing µ-oscillation), and each phase condition for 2 different EEG montages corresponding to oscillations preferentially originating in precentral gyrus (premotor cortex) vs. postcentral gyrus (somatosensory cortex), extracted using FCC3h vs. C3 centered EEG montages. RESULTS The negative vs. positive peak of sensorimotor µ-rhythm as extracted from the C3 montage (postcentral gyrus, somatosensory cortex) correlated with states of high vs. low corticospinal excitability (p < 0.001), replicating previous findings. However, no significant correlation was found for sensorimotor µ-rhythm as extracted from the neighboring FCC3 montage (precentral gyrus, premotor cortex). This implies that EEG-signals from the somatosensory cortex are better predictors of corticospinal excitability than EEG-signals from the motor areas. CONCLUSIONS The extraction of a brain oscillation whose phase corresponds to corticospinal excitability is highly sensitive to the selected EEG montage and the location of the EEG sensors on the scalp. Here, the cortical source of EEG oscillations predicting response amplitude does not correspond to the cortical target of the stimulation, indicating that even in this simple case, a specific neuronal pathway from somatosensory cortex to primary motor cortex is involved.
Collapse
Affiliation(s)
- Christoph Zrenner
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie Institute for Clinical Brain Research, University of Tübingen, Germany; Department of Psychiatry, University of Toronto, Toronto, Canada; Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Canada; Institute for Biomedical Engineering, University of Toronto, Toronto, Canada
| | - Paolo Belardinelli
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie Institute for Clinical Brain Research, University of Tübingen, Germany; Center for Mind/Brain Sciences - CIMeC, University of Trento, Rovereto, Italy
| | - Maria Ermolova
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie Institute for Clinical Brain Research, University of Tübingen, Germany
| | - Pedro Caldana Gordon
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie Institute for Clinical Brain Research, University of Tübingen, Germany
| | - Matti Stenroos
- Department of Neuroscience and Biomedical Engineering, Aalto University, Finland
| | - Brigitte Zrenner
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie Institute for Clinical Brain Research, University of Tübingen, Germany; Department of Psychiatry, University of Toronto, Toronto, Canada; Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Canada
| | - Ulf Ziemann
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie Institute for Clinical Brain Research, University of Tübingen, Germany.
| |
Collapse
|
22
|
TMS Does Not Increase BOLD Activity at the Site of Stimulation: A Review of All Concurrent TMS-fMRI Studies. eNeuro 2022; 9:9/4/ENEURO.0163-22.2022. [PMID: 35981879 PMCID: PMC9410768 DOI: 10.1523/eneuro.0163-22.2022] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/14/2022] [Accepted: 06/30/2022] [Indexed: 11/21/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) is widely used for understanding brain function in neurologically intact subjects and for the treatment of various disorders. However, the precise neurophysiological effects of TMS at the site of stimulation remain poorly understood. The local effects of TMS can be studied using concurrent TMS-functional magnetic resonance imaging (fMRI), a technique where TMS is delivered during fMRI scanning. However, although concurrent TMS-fMRI was developed over 20 years ago and dozens of studies have used this technique, there is still no consensus on whether TMS increases blood oxygen level-dependent (BOLD) activity at the site of stimulation. To address this question, here we review all previous concurrent TMS-fMRI studies that reported analyses of BOLD activity at the target location. We find evidence that TMS increases local BOLD activity when stimulating the primary motor (M1) and visual (V1) cortices but that these effects are likely driven by the downstream consequences of TMS (finger twitches and phosphenes). However, TMS does not appear to increase BOLD activity at the site of stimulation for areas outside of the M1 and V1 when conducted at rest. We examine the possible reasons for such lack of BOLD signal increase based on recent work in nonhuman animals. We argue that the current evidence points to TMS inducing periods of increased and decreased neuronal firing that mostly cancel each other out and therefore lead to no change in the overall BOLD signal.
Collapse
|
23
|
New updates on transcranial magnetic stimulation in chronic pain. Curr Opin Support Palliat Care 2022; 16:65-70. [DOI: 10.1097/spc.0000000000000591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
24
|
Sasaki R, Semmler JG, Opie GM. Threshold Tracked Short-Interval Intracortical Inhibition More Closely Predicts the Cortical Response to Transcranial Magnetic Stimulation. Neuromodulation 2022; 25:614-623. [DOI: 10.1016/j.neurom.2021.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/19/2021] [Accepted: 10/26/2021] [Indexed: 01/14/2023]
|
25
|
Shraim MA, Massé-Alarie H, Salomoni SE, Hodges PW. Can training of a skilled pelvic movement change corticomotor control of back muscles? Comparison of single and paired-pulse transcranial magnetic stimulation. Eur J Neurosci 2022; 56:3705-3719. [PMID: 35501123 PMCID: PMC9540878 DOI: 10.1111/ejn.15683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 04/22/2022] [Accepted: 04/25/2022] [Indexed: 11/30/2022]
Abstract
Evidence suggests excitability of the motor cortex (M1) changes in response to motor skill learning of the upper limb. Few studies have examined immediate changes in corticospinal excitability and intra‐cortical mechanisms following motor learning in the lower back. Further, it is unknown which transcranial magnetic stimulation (TMS) paradigms are likely to reveal changes in cortical function in this region. This study aimed to (1) compare corticospinal excitability and intra‐cortical mechanisms in the lower back region of M1 before and after a single session of lumbopelvic tilt motor learning task in healthy people and (2) compare these measures between two TMS coils and two methods of recruitment curve (RC) acquisition. Twenty‐eight young participants (23.6 ± 4.6 years) completed a lumbopelvic tilting task involving three 5‐min blocks. Single‐pulse (RC from 70% to 150% of active motor threshold) and paired‐pulse TMS measures (ICF, SICF and SICI) were undertaken before (using 2 coils: figure‐of‐8 and double cone) and after (using double cone coil only) training. RCs were also acquired using a traditional and rapid method. A significant increase in corticospinal excitability was found after training as measured by RC intensities, but this was not related to the RC slope. No significant differences were found for paired‐pulse measures after training. Finally, there was good agreement between RC parameters when measured with the two different TMS coils or different acquisition methods (traditional vs. rapid). Changes in corticospinal excitability after a single session of lumbopelvic motor learning task are seen, but these changes are not explained by changes in intra‐cortical mechanisms.
Collapse
Affiliation(s)
- Muath A Shraim
- The University of Queensland, NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury & Health, School of Health & Rehabilitation Sciences, QLD, Australia
| | - Hugo Massé-Alarie
- The University of Queensland, NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury & Health, School of Health & Rehabilitation Sciences, QLD, Australia.,Centre interdisciplinaire de recherche en réadaptation et integration sociale (CIRRIS), Université Laval, Québec, QC, Canada
| | - Sauro E Salomoni
- The University of Queensland, NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury & Health, School of Health & Rehabilitation Sciences, QLD, Australia
| | - Paul W Hodges
- The University of Queensland, NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury & Health, School of Health & Rehabilitation Sciences, QLD, Australia
| |
Collapse
|
26
|
Heimbuch IS, Fan TK, Wu AD, Faas GC, Charles AC, Iacoboni M. Ultrasound stimulation of the motor cortex during tonic muscle contraction. PLoS One 2022; 17:e0267268. [PMID: 35442956 PMCID: PMC9020726 DOI: 10.1371/journal.pone.0267268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 04/05/2022] [Indexed: 11/18/2022] Open
Abstract
Transcranial ultrasound stimulation (tUS) shows potential as a noninvasive brain stimulation (NIBS) technique, offering increased spatial precision compared to other NIBS techniques. However, its reported effects on primary motor cortex (M1) are limited. We aimed to better understand tUS effects in human M1 by performing tUS of the hand area of M1 (M1hand) during tonic muscle contraction of the index finger. Stimulation during muscle contraction was chosen because of the transcranial magnetic stimulation-induced phenomenon known as cortical silent period (cSP), in which transcranial magnetic stimulation (TMS) of M1hand involuntarily suppresses voluntary motor activity. Since cSP is widely considered an inhibitory phenomenon, it presents an ideal parallel for tUS, which has often been proposed to preferentially influence inhibitory interneurons. Recording electromyography (EMG) of the first dorsal interosseous (FDI) muscle, we investigated effects on muscle activity both during and after tUS. We found no change in FDI EMG activity concurrent with tUS stimulation. Using single-pulse TMS, we found no difference in M1 excitability before versus after sparsely repetitive tUS exposure. Using acoustic simulations in models made from structural MRI of the participants that matched the experimental setups, we estimated in-brain pressures and generated an estimate of cumulative tUS exposure experienced by M1hand for each subject. We were unable to find any correlation between cumulative M1hand exposure and M1 excitability change. We also present data that suggest a TMS-induced MEP always preceded a near-threshold cSP.
Collapse
Affiliation(s)
- Ian S. Heimbuch
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
- Ahmanson-Lovelace Brain Mapping Center, University of California, Los Angeles, Los Angeles, California, United States of America
- * E-mail:
| | - Tiffany K. Fan
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Allan D. Wu
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Evanston, Illinois, United States of America
| | - Guido C. Faas
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Andrew C. Charles
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Marco Iacoboni
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, United States of America
- Ahmanson-Lovelace Brain Mapping Center, University of California, Los Angeles, Los Angeles, California, United States of America
| |
Collapse
|
27
|
Biondi A, Rocchi L, Santoro V, Rossini PG, Beatch GN, Richardson MP, Premoli I. Spontaneous and TMS-related EEG changes as new biomarkers to measure anti-epileptic drug effects. Sci Rep 2022; 12:1919. [PMID: 35121751 PMCID: PMC8817040 DOI: 10.1038/s41598-022-05179-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 01/05/2022] [Indexed: 01/02/2023] Open
Abstract
Robust biomarkers for anti-epileptic drugs (AEDs) activity in the human brain are essential to increase the probability of successful drug development. The frequency analysis of electroencephalographic (EEG) activity, either spontaneous or evoked by transcranial magnetic stimulation (TMS-EEG) can provide cortical readouts for AEDs. However, a systematic evaluation of the effect of AEDs on spontaneous oscillations and TMS-related spectral perturbation (TRSP) has not yet been provided. We studied the effects of Lamotrigine, Levetiracetam, and of a novel potassium channel opener (XEN1101) in two groups of healthy volunteers. Levetiracetam suppressed TRSP theta, alpha and beta power, whereas Lamotrigine decreased delta and theta but increased the alpha power. Finally, XEN1101 decreased TRSP delta, theta, alpha and beta power. Resting-state EEG showed a decrease of theta band power after Lamotrigine intake. Levetiracetam increased theta, beta and gamma power, while XEN1101 produced an increase of delta, theta, beta and gamma power. Spontaneous and TMS-related cortical oscillations represent a powerful tool to characterize the effect of AEDs on in vivo brain activity. Spectral fingerprints of specific AEDs should be further investigated to provide robust and objective biomarkers of biological effect in human clinical trials.
Collapse
Affiliation(s)
- Andrea Biondi
- Division of Neuroscience, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, Ground Floor (G.33.08), 5 Cutcombe Road, Camberwell, London, SE5 9RX, UK.
| | - L Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK.,Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - V Santoro
- Division of Neuroscience, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, Ground Floor (G.33.08), 5 Cutcombe Road, Camberwell, London, SE5 9RX, UK
| | - P G Rossini
- Division of Neuroscience, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, Ground Floor (G.33.08), 5 Cutcombe Road, Camberwell, London, SE5 9RX, UK
| | - G N Beatch
- Xenon Pharmaceuticals Inc., Burnaby, Canada
| | - M P Richardson
- Division of Neuroscience, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, Ground Floor (G.33.08), 5 Cutcombe Road, Camberwell, London, SE5 9RX, UK
| | - I Premoli
- Division of Neuroscience, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, Ground Floor (G.33.08), 5 Cutcombe Road, Camberwell, London, SE5 9RX, UK
| |
Collapse
|
28
|
EEG as a marker of brain plasticity in clinical applications. HANDBOOK OF CLINICAL NEUROLOGY 2022; 184:91-104. [PMID: 35034760 DOI: 10.1016/b978-0-12-819410-2.00029-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Neural networks are dynamic, and the brain has the capacity to reorganize itself. This capacity is named neuroplasticity and is fundamental for many processes ranging from learning and adaptation to new environments to the response to brain injuries. Measures of brain plasticity involve several techniques, including neuroimaging and neurophysiology. Electroencephalography, often used together with other techniques, is a common tool for prognostic and diagnostic purposes, and cortical reorganization is reflected by EEG measurements. Changes of power bands in different cortical areas occur with fatigue and in response to training stimuli leading to learning processes. Sleep has a fundamental role in brain plasticity, restoring EEG bands alterations and promoting consolidation of learning. Exercise and physical inactivity have been extensively studied as both strongly impact brain plasticity. Indeed, EEG studies showed the importance of the physical activity to promote learning and the effects of inactivity or microgravity on cortical reorganization to cope with absent or altered sensorimotor stimuli. Finally, this chapter will describe some of the EEG changes as markers of neural plasticity in neurologic conditions, focusing on cerebrovascular and neurodegenerative diseases. In conclusion, neuroplasticity is the fundamental mechanism necessary to ensure adaptation to new stimuli and situations, as part of the dynamicity of life.
Collapse
|
29
|
The Effectiveness of Transcranial Magnetic Stimulation (TMS) Paradigms as Treatment Options for Recovery of Language Deficits in Chronic Poststroke Aphasia. Behav Neurol 2022; 2022:7274115. [PMID: 35069929 PMCID: PMC8767406 DOI: 10.1155/2022/7274115] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 12/18/2021] [Indexed: 11/29/2022] Open
Abstract
Background In an effort to boost aphasia recovery, modern rehabilitation, in addition to speech and language therapy (SALT), is increasingly incorporating noninvasive methods of brain stimulation. The present study is aimed at investigating the effectiveness of two paradigms of neuronavigated repetitive transcranial magnetic stimulation (rTMS): (i) 1 Hz rTMS and (ii) continuous theta burst stimulation (cTBS) each as a standalone treatment for chronic aphasia poststroke. Methods A single subject experimental design (SSED) trial was carried out in which six people with aphasia (PWA) were recruited, following a single left hemispheric stroke more than six months prior to the study. Three individuals were treated with 1 Hz rTMS, and the remaining three were treated with cTBS. In all cases, TMS was applied over the right pars triangularis (pTr). Language assessment, with standardized and functional measures, and cognitive evaluations were carried out at four time points: twice prior to treatment (baseline), one day immediately posttreatment, and at follow-up two months after treatment was terminated. Quality of life (QoL) was also assessed at baseline and two months posttreatment. In addition, one of the participants with severe global aphasia was followed up again one and two years posttherapy. Results For all participants, both rTMS paradigms (1 Hz rTMS and cTBS) generated trends towards improvement in several language skills (i.e., verbal receptive language, expressive language, and naming and reading) one day after treatment and/or two months after therapy. Rated QoL remained stable in three individuals, but for the other three, the communication scores of the QoL were reduced, while two of them also showed a decline in the psychological scores. The participant that was treated with cTBS and followed for up to two years showed that the significant improvement she had initially exhibited in comprehension and reading skills two months after TMS (1st follow-up) was sustained for at least up to two years. Conclusion From the current findings, it is suggested that inhibitory TMS over the right pTr has the potential to drive neuroplastic changes as a standalone treatment that facilitates language recovery in poststroke aphasia.
Collapse
|
30
|
Edinoff AN, Hegefeld TL, Petersen M, Patterson JC, Yossi C, Slizewski J, Osumi A, Cornett EM, Kaye A, Kaye JS, Javalkar V, Viswanath O, Urits I, Kaye AD. Transcranial Magnetic Stimulation for Post-traumatic Stress Disorder. Front Psychiatry 2022; 13:701348. [PMID: 35711594 PMCID: PMC9193572 DOI: 10.3389/fpsyt.2022.701348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 05/13/2022] [Indexed: 11/17/2022] Open
Abstract
Post-traumatic stress disorder (PTSD) is a psychiatric disorder that causes significant functional impairment and is related to altered stress response and reinforced learned fear behavior. PTSD has been found to impact three functional networks in the brain: default mode, executive control, and salience. The executive control network includes the dorsolateral prefrontal cortex (DLPFC) and lateral PPC. The salience network involves the anterior cingulate cortex, anterior insula, and amygdala. This latter network has been found to have increased functional connectivity in PTSD. Transcranial Magnetic Stimulation (TMS) is a technique used in treating PTSD and involves stimulating specific portions of the brain through electromagnetic induction. Currently, high-frequency TMS applied to the left dorsolateral prefrontal cortex (DLPFC) is approved for use in treating major depressive disorder (MDD) in patients who have failed at least one medication trial. In current studies, high-frequency stimulation has been shown to be more effective in PTSD rating scales posttreatment than low-frequency stimulation. The most common side effect is headache and scalp pain treated by mild analgesics. Seizures are a rare side effect and are usually due to predisposing factors. Studies have been done to assess the overall efficacy of TMS. However, results have been conflicting, and sample sizes were small. More research should be done with larger sample sizes to test the efficacy of TMS in the treatment of PTSD. Overall, TMS is a relatively safe treatment. Currently, the only FDA- approved to treat refractory depression, but with the potential to treat many other conditions.
Collapse
Affiliation(s)
- Amber N Edinoff
- Department of Psychiatry and Behavioral Medicine, Louisiana State University Health Science Center Shreveport, Shreveport, LA, United States
| | - Tanner L Hegefeld
- Department of Psychiatry and Behavioral Medicine, Louisiana State University Health Science Center Shreveport, Shreveport, LA, United States
| | - Murray Petersen
- Department of Psychiatry and Behavioral Medicine, Louisiana State University Health Science Center Shreveport, Shreveport, LA, United States
| | - James C Patterson
- Department of Psychiatry and Behavioral Medicine, Louisiana State University Health Science Center Shreveport, Shreveport, LA, United States
| | | | - Jacob Slizewski
- Creighton University School of Medicine, Omaha, NE, United States
| | - Ashley Osumi
- Creighton University School of Medicine, Omaha, NE, United States
| | - Elyse M Cornett
- Department of Anesthesiology, Louisiana State University Shreveport, Shreveport, LA, United States
| | - Adam Kaye
- Department of Pharmacy Practice, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA, United States
| | - Jessica S Kaye
- Department of Pharmacy Practice, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA, United States
| | - Vijayakumar Javalkar
- Department of Neurology, Louisiana State University Shreveport, Shreveport, LA, United States
| | - Omar Viswanath
- College of Medicine-Phoenix, University of Arizona, Phoenix, AZ, United States.,Department of Anesthesiology, Creighton University School of Medicine, Omaha, NE, United States.,Valley Anesthesiology and Pain Consultants-Envision Physician Services, Phoenix, AZ, United States
| | - Ivan Urits
- Department of Anesthesiology, Louisiana State University Shreveport, Shreveport, LA, United States.,Southcoast Health, Southcoast Physicians Group Pain Medicine, Wareham, MA, United States
| | - Alan D Kaye
- Department of Anesthesiology, Louisiana State University Shreveport, Shreveport, LA, United States
| |
Collapse
|
31
|
Bihemispheric sensorimotor oscillatory network states determine cortical responses to transcranial magnetic stimulation. Brain Stimul 2021; 15:167-178. [PMID: 34896304 DOI: 10.1016/j.brs.2021.12.002] [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: 10/20/2021] [Revised: 12/05/2021] [Accepted: 12/07/2021] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Brain responses to external stimuli vary with fluctuating states of neuronal activity. Previous work has demonstrated effects of phase and power of the ongoing local sensorimotor μ-alpha-oscillation on responses to transcranial magnetic stimulation (TMS) of motor cortex (M1). However, M1 is part of a distributed network, and the effects of oscillatory activity in this network on TMS-evoked EEG responses (TEPs) have not been explored. OBJECTIVES To determine the effects of oscillatory activity in the bihemispheric sensorimotor network on TEPs. METHODS 31 healthy subjects received single-pulse TMS of the left M1 hand area during EEG recording. Ongoing bihemispheric sensorimotor cortex oscillatory states were reconstructed from the EEG directly preceding TMS, and inferred by a data-driven method combining a multivariate autoregressive model and a Hidden Markov model. TEP amplitudes (P25, N45, P70, N100 and P180) were then compared between different bihemispheric sensorimotor cortex oscillatory states. RESULTS Four bihemispheric sensorimotor cortex oscillatory states were identified, with different interhemispheric expressions of theta and alpha oscillations. High alpha-power states in the stimulated sensorimotor cortex increased P25 amplitude. Alpha power in the alpha-alpha state (stimulated - non-stimulated hemisphere) correlated in both hemispheres with N45 amplitude. Theta power in the alpha-theta state correlated in the non-stimulated hemisphere with P70 amplitude. CONCLUSIONS Bihemispheric sensorimotor cortex oscillatory states contribute to TEPs, with a relevance shift from stimulated to non-stimulated M1 from P25 over N45 to P70. This significantly extends previous findings: not only ongoing local oscillations but distributed network oscillatory states determine cortical responsiveness to external stimuli.
Collapse
|
32
|
Davis M, Wang Y, Bao S, Buchanan JJ, Wright DL, Lei Y. The Interactions Between Primary Somatosensory and Motor Cortex during Human Grasping Behaviors. Neuroscience 2021; 485:1-11. [PMID: 34848261 DOI: 10.1016/j.neuroscience.2021.11.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/26/2021] [Accepted: 11/24/2021] [Indexed: 11/28/2022]
Abstract
Afferent inputs to the primary somatosensory cortex (S1) are differentially processed during precision and power grip in humans. However, it remains unclear how S1 interacts with the primary motor cortex (M1) during these two grasping behaviors. To address this question, we measured short-latency afferent inhibition (SAI), reflecting S1-M1 interactions via thalamo-cortical pathways, using paired-pulse transcranial magnetic stimulation (TMS) during precision and power grip. The TMS coil over the hand representation of M1 was oriented in the posterior-anterior (PA) and anterior-posterior (AP) direction to activate distinct sets of corticospinal neurons. We found that SAI increased during precision compared with power grip when AP, but not PA, currents were applied. Notably, SAI tested in the AP direction were similar during two-digit than five-digit precision grip. The M1 receives movement information from S1 through direct cortico-cortical pathways, so intra-hemispheric S1-M1 interactions using dual-site TMS were also evaluated. Stimulation of S1 attenuated M1 excitability (S1-M1 inhibition) during precision and power grip, while the S1-M1 inhibition ratio remained similar across tasks. Taken together,our findings suggest that distinct neural mechanisms for S1-M1 interactions mediate precision and power grip, presumably by modulating neural activity along thalamo-cortical pathways.
Collapse
Affiliation(s)
- Madison Davis
- Department of Health and Kinesiology, Texas A&M University, College Station, TX 77843, United States
| | - Yiyu Wang
- Department of Health and Kinesiology, Texas A&M University, College Station, TX 77843, United States
| | - Shancheng Bao
- Department of Health and Kinesiology, Texas A&M University, College Station, TX 77843, United States
| | - John J Buchanan
- Department of Health and Kinesiology, Texas A&M University, College Station, TX 77843, United States
| | - David L Wright
- Department of Health and Kinesiology, Texas A&M University, College Station, TX 77843, United States
| | - Yuming Lei
- Department of Health and Kinesiology, Texas A&M University, College Station, TX 77843, United States.
| |
Collapse
|
33
|
Mrachacz-Kersting N, Stevenson AJT, Ziemann U. Short-interval intracortical inhibition and facilitation targeting upper and lower limb muscles. Sci Rep 2021; 11:21993. [PMID: 34754010 PMCID: PMC8578654 DOI: 10.1038/s41598-021-01348-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/27/2021] [Indexed: 11/30/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) can be used to study excitability of corticospinal neurons in human motor cortex. It is currently not fully elucidated if corticospinal neurons in the hand vs. leg representation show the same or different regulation of their excitability by GABAAergic and glutamatergic interneuronal circuitry. Using a paired-pulse TMS protocol we tested short-interval intracortical inhibition (SICI) and short-interval intracortical facilitation (SICF) in 18 healthy participants. Motor evoked potentials were evoked in one hand (abductor digiti minimi) and one leg muscle (tibialis anterior), with systematic variation of the intensities of the first (S1) and second (S2) pulse between 60 and 140% resting motor threshold (RMT) in 10% steps, at two interstimulus intervals of 1.5 and 2.1 ms. For the hand and leg motor representations and for both interstimulus intervals, SICI occurred if the intensities of S1 < RMT and S2 > RMT, while SICF predominated if S1 = S2 ≤ RMT, or S1 > RMT and S2 < RMT. Findings confirm and extend previous evidence that the regulation of excitability of corticospinal neurons of the hand versus leg representation in human primary cortex through GABAAergic and glutamatergic interneuronal circuits is highly similar, and that corticospinal neurons of both representations are activated by TMS transsynaptically in largely identical ways.
Collapse
Affiliation(s)
| | | | - Ulf Ziemann
- Department of Neurology and Stroke, University of Tübingen, Tübingen, Germany.,Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| |
Collapse
|
34
|
Deng X, Wang J, Zang Y, Li Y, Fu W, Su Y, Chen X, Du B, Dong Q, Chen C, Li J. Intermittent theta burst stimulation over the parietal cortex has a significant neural effect on working memory. Hum Brain Mapp 2021; 43:1076-1086. [PMID: 34730863 PMCID: PMC8764471 DOI: 10.1002/hbm.25708] [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: 07/17/2021] [Revised: 10/12/2021] [Accepted: 10/21/2021] [Indexed: 11/17/2022] Open
Abstract
The crucial role of the parietal cortex in working memory (WM) storage has been identified by fMRI studies. However, it remains unknown whether repeated parietal intermittent theta‐burst stimulation (iTBS) can improve WM. In this within‐subject randomized controlled study, under the guidance of fMRI‐identified parietal activation in the left hemisphere, 22 healthy adults received real and sham iTBS sessions (five consecutive days, 600 pulses per day for each session) with an interval of 9 months between the two sessions. Electroencephalography signals of each subject before and after both iTBS sessions were collected during a change detection task. Changes in contralateral delay activity (CDA) and K‐score were then calculated to reflect neural and behavioral WM improvement. Repeated‐measures ANOVA suggested that real iTBS increased CDA more than the sham one (p = .011 for iTBS effect). Further analysis showed that this effect was more significant in the left hemisphere than in the right hemisphere (p = .029 for the hemisphere‐by‐iTBS interaction effect). Pearson correlation analyses showed significant correlations for two conditions between CDA changes in the left hemisphere and K score changes (ps <.05). In terms of the behavioral results, significant K score changes after real iTBS were observed for two conditions, but a repeated‐measures ANOVA showed a nonsignificant main effect of iTBS (p = .826). These results indicate that the current iTBS protocol is a promising way to improve WM capability based on the neural indicator (CDA) but further optimization is needed to produce a behavioral effect.
Collapse
Affiliation(s)
- Xinping Deng
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
| | - Jue Wang
- Institute of Sports Medicine and Health, Chengdu Sport University, Chengdu, China
| | - Yufeng Zang
- Center for Cognition and Brain Disorders, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, China.,Institute of Psychological Sciences, Hangzhou Normal University, Hangzhou, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, China
| | - Yang Li
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
| | - Wenjin Fu
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
| | - Yanyan Su
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
| | - Xiongying Chen
- The National Clinical Research Center for Mental Disorders & Beijing Key Laboratory of Mental Disorders & the Advanced Innovation Center for Human Brain Protection, Beijing Anding Hospital, School of Mental Health, Capital Medical University, Beijing, China
| | - Boqi Du
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
| | - Qi Dong
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
| | - Chuansheng Chen
- Department of Psychological Science, University of California, Irvine, California, USA
| | - Jun Li
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
| |
Collapse
|
35
|
Neva JL, Brown KE, Peters S, Feldman SJ, Mahendran N, Boisgontier MP, Boyd LA. Acute Exercise Modulates the Excitability of Specific Interneurons in Human Motor Cortex. Neuroscience 2021; 475:103-116. [PMID: 34487820 DOI: 10.1016/j.neuroscience.2021.08.032] [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: 03/12/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 10/20/2022]
Abstract
Acute exercise can modulate the excitability of the non-exercised upper-limb representation in the primary motor cortex (M1). Accumulating evidence demonstrates acute exercise affects measures of M1 intracortical excitability, with some studies also showing altered corticospinal excitability. However, the influence of distinct M1 interneuron populations on the modulation of intracortical and corticospinal excitability following acute exercise is currently unknown. We assessed the impact of an acute bout of leg cycling exercise on unique M1 interneuron excitability of a non-exercised intrinsic hand muscle using transcranial magnetic stimulation (TMS) in young adults. Specifically, posterior-to-anterior (PA) and anterior-to-posterior (AP) TMS current directions were used to measure the excitability of distinct populations of interneurons before and after an acute bout of exercise or rest. Motor evoked potentials (MEPs) and short-interval intracortical inhibition (SICI) were measured in the PA and AP current directions in M1 at two time points separated by 25 min of rest, as well as immediately and 30 min after a 25-minute bout of moderate-intensity cycling exercise. Thirty minutes after exercise, MEP amplitudes were significantly larger than other timepoints when measured with AP current, whereas MEP amplitudes derived from PA current did not show this effect. Similarly, SICI was significantly decreased immediately following acute exercise measured with AP but not PA current. Our findings suggest that the excitability of unique M1 interneurons are differentially modulated by acute exercise. These results indicate that M1 interneurons preferentially activated by AP current may play an important role in the exercise-induced modulation of intracortical and corticospinal excitability.
Collapse
Affiliation(s)
- Jason L Neva
- Université de Montréal, École de kinésiologie et des sciences de l'activité physique, Faculté de médecine, Montréal, QC, Canada; Centre de recherche de l'institut universitaire de gériatrie de Montréal, Montréal, QC, Canada.
| | - Katlyn E Brown
- University of Waterloo, Department of Kinesiology, Applied Health Sciences, Waterloo, ON, Canada
| | - Sue Peters
- Rehabilitation Research Program, GF Strong Rehabilitation Centre, Vancouver Coastal Health Research Institute, Vancouver, BC, Canada; University of British Columbia, Department of Physical Therapy, Faculty of Medicine, Vancouver, BC, Canada
| | - Samantha J Feldman
- Graduate Program in Clinical Developmental Neuropsychology, Department of Psychology, York University, Toronto, ON, Canada
| | - Niruthikha Mahendran
- University of Queensland, Discipline of Physiotherapy, School of Health and Rehabilitation Sciences, Brisbane, Australia
| | - Matthieu P Boisgontier
- School of Rehabilitation Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa ON, Canada; Bruyère Research Institute, Ottawa, ON, Canada
| | - Lara A Boyd
- University of British Columbia, Department of Physical Therapy, Faculty of Medicine, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
36
|
Roumengous T, Reutter AB, Peterson CL. Effect of low-cost transcranial magnetic stimulation navigation on hotspot targeting and motor evoked potential variability in the biceps brachii. Restor Neurol Neurosci 2021; 39:319-328. [PMID: 34657854 DOI: 10.3233/rnn-211207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Transcranial magnetic stimulation (TMS) can monitor or modulate brain excitability. However, reliability of TMS outcomes depends on consistent coil placement during stimulation. Neuronavigated TMS systems can address this issue, but their cost limits their use outside of specialist research environments. OBJECTIVE The objective was to evaluate the performance of a low-cost navigated TMS approach in improving coil placement consistency and its effect on motor evoked potentials (MEPs) when targeting the biceps brachii at rest and during voluntary contractions. METHODS We implemented a navigated TMS system using a low-cost 3D camera system and open-source software environment programmed using the Unity 3D engine. MEPs were collected from the biceps brachii at rest and during voluntary contractions across two sessions in ten non-disabled individuals. Motor hotspots were recorded and targeted via two conditions: navigated and conventional. RESULTS The low-cost navigated TMS system reduced coil orientation error (pitch: 1.18°±1.2°, yaw: 1.99°±1.9°, roll: 1.18°±2.2° with navigation, versus pitch: 3.7°±5.7°, yaw: 3.11°±3.1°, roll: 3.8°±9.1° with conventional). The improvement in coil orientation had no effect on MEP amplitudes and variability. CONCLUSIONS The low-cost system is a suitable alternative to expensive systems in tracking the motor hotspot between sessions and quantifying the error in coil placement when delivering TMS. Biceps MEP variability reflects physiological variability across a range of voluntary efforts, that can be captured equally well with navigated or conventional approaches of coil locating.
Collapse
Affiliation(s)
- Thibault Roumengous
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Alec B Reutter
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Carrie L Peterson
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, Virginia, USA
| |
Collapse
|
37
|
Lee HH, Blumberger DM, Lenze EJ, Anderson SJ, Barch DM, Black KJ, Cristancho P, Daskalakis ZJ, Eisenstein SA, Huang Y, Li S, Lissemore J, McConathy J, Mulsant BH, Rajji TK, Reynolds CF, Su Y, Tu Z, Voineskos D, Karp JF. Low-Dose Augmentation With Buprenorphine for Treatment-Resistant Depression: A Multisite Randomized Controlled Trial With Multimodal Assessment of Target Engagement. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2021; 2:127-135. [PMID: 36325158 PMCID: PMC9616305 DOI: 10.1016/j.bpsgos.2021.09.003] [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: 08/12/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 01/31/2023] Open
Abstract
Background The experimental therapeutics approach that combines a placebo-controlled clinical trial with translational neuroscience methods can provide a better understanding of both the clinical and physiological effects of pharmacotherapy. We aimed to test the efficacy and tolerability of low-dose augmentation with buprenorphine (BPN) for treatment-resistant depression, combined with multimodal assessment of target engagement. Methods In this multisite randomized clinical trial, 85 participants ≥50 years of age with a major depressive episode that had not responded to venlafaxine extended release were randomized to augmentation with BPN or placebo for 8 weeks. The primary outcome measure was the Montgomery-Åsberg Depression Rating Scale. In addition, three linked experiments were conducted to test target engagement: 1) functional magnetic resonance imaging using the monetary incentive delay task, 2) brain positron emission tomography of healthy participants using a novel kappa opioid receptor antagonist tracer [11C]LY2795050, and 3) transcranial magnetic stimulation measure of cortical transmission after daily BPN administration. Results The mean ± SD dosage of BPN was 0.59 ± 0.33 mg/day. There were no significant differences between the BPN and placebo groups in Montgomery-Åsberg Depression Rating Scale changes over time or adverse effects. BPN administration had minimal effects on functional magnetic resonance imaging blood oxygen level-dependent responses in regions involved in reward anticipation and response, no significant displacement of kappa opioid receptor radioligand in positron emission tomography imaging, and no significant changes in transcranial magnetic stimulation measures of inhibitory and excitatory cortical transmission. Conclusions Our findings suggest a lack of clinical effect of low-dose BPN augmentation and lack of target engagement with this dosage and physiological probes.
Collapse
Affiliation(s)
- Hyewon H. Lee
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada,Address correspondence to Hyewon H. Lee, M.D.
| | - Daniel M. Blumberger
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada,Temerty Centre for Therapeutic Brain Intervention and Campbell Family Research Institute at the Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Eric J. Lenze
- Department of Psychiatry, Washington University in St. Louis, St. Louis, Missouri
| | - Stewart J. Anderson
- Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Deanna M. Barch
- Departments of Psychological & Brain Sciences, Psychiatry, and Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Kevin J. Black
- Departments of Psychiatry, Neurology, Radiology, and Neuroscience, Washington University in St. Louis, St. Louis, Missouri
| | - Pilar Cristancho
- Department of Psychiatry, Washington University in St. Louis, St. Louis, Missouri
| | - Zafiris J. Daskalakis
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada,Temerty Centre for Therapeutic Brain Intervention and Campbell Family Research Institute at the Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Sarah A. Eisenstein
- Department of Psychiatry, Washington University in St. Louis, St. Louis, Missouri
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Songye Li
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Jennifer Lissemore
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada,Temerty Centre for Therapeutic Brain Intervention and Campbell Family Research Institute at the Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Jonathan McConathy
- Molecular Imaging and Therapeutics, Department of Radiology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Benoit H. Mulsant
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada,Temerty Centre for Therapeutic Brain Intervention and Campbell Family Research Institute at the Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Tarek K. Rajji
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada,Temerty Centre for Therapeutic Brain Intervention and Campbell Family Research Institute at the Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Charles F. Reynolds
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Yi Su
- Banner Alzheimer’s Institute and Arizona Alzheimer’s Consortium, Phoenix, Arizona
| | - Zhude Tu
- Department of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Daphne Voineskos
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada,Temerty Centre for Therapeutic Brain Intervention and Campbell Family Research Institute at the Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Jordan F. Karp
- Department of Psychiatry, University of Arizona College of Medicine, Tucson, Arizona
| |
Collapse
|
38
|
Desmons M, Rohel A, Desgagnés A, Mercier C, Massé-Alarie H. Influence of different transcranial magnetic stimulation current directions on the corticomotor control of lumbar erector spinae muscles during a static task. J Neurophysiol 2021; 126:1276-1288. [PMID: 34550037 DOI: 10.1152/jn.00137.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Different directions of transcranial magnetic stimulation (TMS) can activate different neuronal circuits. Whereas posteroanterior current (PA-TMS) depolarizes mainly interneurons in primary motor cortex (M1), an anteroposterior current (AP-TMS) has been suggested to activate different M1 circuits and perhaps axons from the premotor regions. Although M1 is also involved in the control of axial muscles, no study has explored whether different current directions activate different M1 circuits that may have distinct functional roles. The aim of the study was to compare the effect of different current directions (PA- and AP-TMS) on the corticomotor control and spatial cortical organization of the lumbar erector spinae muscle (LES). Thirty-four healthy participants were recruited for two independent experiments, and LES motor-evoked potentials (MEPs) were recorded. In experiment 1 (n = 17), active motor threshold (AMT), MEP latencies, recruitment curve (90% to 160% AMT), and excitatory and inhibitory intracortical mechanisms by paired-pulse TMS (80% followed by 120% AMT stimuli at 2-, 3-, 10-, and 15-ms interstimulus intervals) were tested with a double-cone (n = 12) and a figure-of-eight (n = 5) coil. In experiment 2 (n = 17), LES cortical representations were tested with PA- and AP-TMS. AMT was higher for AP- compared with PA-TMS (P = 0.002). Longer latencies with AP-TMS were present compared with PA-TMS (P = 0.017). AP-TMS produced more inhibition compared with PA-TMS at 2 ms and 3 ms (P = 0.010), but no difference was observed for longer intervals. No difference was found for recruitment curve and mapping. These findings suggest that PA- and AP-TMS may activate different cortical circuits controlling low back muscles, as proposed for hand muscles.NEW & NOTEWORTHY For the first time, anteroposterior and posteroanterior induced electric currents in the brain were compared when targeting back muscle representation with transcranial magnetic stimulation. The use of the anteroposterior current resulted in later response latency, larger inhibition probed by paired-pulse stimulation, and higher motor threshold. These important differences between current directions suggest that each of the current directions may recruit specific cortical circuits involved in the control of back muscles, similar to that for hand muscles.
Collapse
Affiliation(s)
- Mikaël Desmons
- CIRRIS Research Centre, Université Laval, Quebec City, Quebec, Canada
| | - Antoine Rohel
- CIRRIS Research Centre, Université Laval, Quebec City, Quebec, Canada
| | - Amélie Desgagnés
- CIRRIS Research Centre, Université Laval, Quebec City, Quebec, Canada
| | - Catherine Mercier
- CIRRIS Research Centre, Université Laval, Quebec City, Quebec, Canada.,Rehabilitation Unit, Université Laval, Quebec City, Quebec, Canada
| | - Hugo Massé-Alarie
- CIRRIS Research Centre, Université Laval, Quebec City, Quebec, Canada.,Rehabilitation Unit, Université Laval, Quebec City, Quebec, Canada
| |
Collapse
|
39
|
Meder A, Liepelt-Scarfone I, Sulzer P, Berg D, Laske C, Preische O, Desideri D, Zipser CM, Salvadore G, Tatikola K, Timmers M, Ziemann U. Motor cortical excitability and paired-associative stimulation-induced plasticity in amnestic mild cognitive impairment and Alzheimer’s disease. Clin Neurophysiol 2021; 132:2264-2273. [DOI: 10.1016/j.clinph.2021.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 12/31/2020] [Accepted: 01/07/2021] [Indexed: 12/14/2022]
|
40
|
Intermittent Theta Burst Stimulation to the Primary Motor Cortex Reduces Cortical Inhibition: A TMS-EEG Study. Brain Sci 2021; 11:brainsci11091114. [PMID: 34573136 PMCID: PMC8472376 DOI: 10.3390/brainsci11091114] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/17/2021] [Accepted: 08/19/2021] [Indexed: 01/08/2023] Open
Abstract
Introduction: The aim of this study was to reveal the effects of intermittent theta burst stimulation (iTBS) in modulating cortical networks using transcranial magnetic stimulation and electroencephalography (TMS-EEG) recording. Methods: Eighteen young adults participated in our study and received iTBS to the primary motor cortex (M1), supplementary motor area, and the primary visual cortex in three separate sessions. A finger tapping task and ipsilateral single-pulse TMS-EEG recording for the M1 were administrated before and after iTBS in each session. The effects of iTBS in motor performance and TMS-evoked potentials (TEPs) were investigated. Results: The results showed that iTBS to the M1, but not supplementary motor area or the primary visual cortex, significantly reduced the N100 amplitude of M1 TEPs in bilateral hemispheres (p = 0.019), with a more prominent effect in the contralateral hemisphere than in the stimulated hemisphere. Moreover, only iTBS to the M1 decreased global mean field power (corrected ps < 0.05), interhemispheric signal propagation (t = 2.53, p = 0.030), and TMS-induced early α-band synchronization (p = 0.020). Conclusion: Our study confirmed the local and remote after-effects of iTBS in reducing cortical inhibition in the M1. TMS-induced oscillations after iTBS for changed cortical excitability in patients with various neurological and psychiatric conditions are worth further exploration.
Collapse
|
41
|
Makarov SN, Wartman WA, Noetscher GM, Fujimoto K, Zaidi T, Burnham EH, Daneshzand M, Nummenmaa A. Degree of improving TMS focality through a geometrically stable solution of an inverse TMS problem. Neuroimage 2021; 241:118437. [PMID: 34332043 PMCID: PMC8561647 DOI: 10.1016/j.neuroimage.2021.118437] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/10/2021] [Accepted: 07/27/2021] [Indexed: 10/31/2022] Open
Abstract
The Transcranial Magnetic Stimulation (TMS) inverse problem (TMS-IP) investigated in this study aims to focus the TMS induced electric field close to a specified target point defined on the gray matter interface in the M1HAND area while otherwise minimizing it. The goal of the study is to numerically evaluate the degree of improvement of the TMS-IP solutions relative to the well-known sulcus-aligned mapping (a projection approach with the 90∘ local sulcal angle). In total, 1536 individual TMS-IP solutions have been analyzed for multiple target points and multiple subjects using the boundary element fast multipole method (BEM-FMM) as the forward solver. Our results show that the optimal TMS inverse-problem solutions improve the focality - reduce the size of the field "hot spot" and its deviation from the target - by approximately 21-33% on average for all considered subjects, all observation points, two distinct coil types, two segmentation types, two intracortical observation surfaces under study, and three tested values of the field threshold. The inverse-problem solutions with the maximized focality simultaneously improve the TMS mapping resolution (differentiation between neighbor targets separated by approximately 10 mm) although this improvement is quite modest. Coil position/orientation and conductivity uncertainties have been included into consideration as the corresponding de-focalization factors. The present results will change when the levels of uncertainties change. Our results also indicate that the accuracy of the head segmentation critically influences the expected TMS-IP performance.
Collapse
Affiliation(s)
- S N Makarov
- Electrical and Computer Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609 USA; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115 USA.
| | - W A Wartman
- Electrical and Computer Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609 USA
| | - G M Noetscher
- Electrical and Computer Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609 USA
| | - K Fujimoto
- Center for Devices and Radiological Health (CDRH), FDA, Silver Spring, MD 20993 USA
| | - T Zaidi
- Center for Devices and Radiological Health (CDRH), FDA, Silver Spring, MD 20993 USA
| | - E H Burnham
- Electrical and Computer Engineering Department, Worcester Polytechnic Institute, Worcester, MA 01609 USA
| | - M Daneshzand
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115 USA
| | - A Nummenmaa
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115 USA
| |
Collapse
|
42
|
Multimodal Evoked Potentials as Candidate Prognostic and Response Biomarkers in Clinical Trials of Multiple Sclerosis. J Clin Neurophysiol 2021; 38:171-180. [PMID: 33958567 DOI: 10.1097/wnp.0000000000000723] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
SUMMARY Evoked potentials (EPs) measure quantitatively and objectively the alterations of central signal propagation in multiple sclerosis and have long been used for diagnosis. More recently, their utility for prognosis has been demonstrated in several studies, summarizing multiple EP modalities in a single score. In particular, visual, somatosensory, and motor EPs are useful because of their sensitivity to pathology in the frequently affected optic nerve, somatosensory tract, and pyramidal system. Quantitative EP scores show higher sensitivity to change than clinical assessment and may be used to monitor disease progression. Visual EP and the visual system have served as a model to study remyelinating therapies in the setting of acute and chronic optic neuritis. This review presents rationale and evidence for using multimodal EP as prognostic and response biomarkers in clinical trials, targeting remyelination or halting disease progression in multiple sclerosis.
Collapse
|
43
|
Oskarsson B, Mauricio EA, Shah JS, Li Z, Rogawski MA. Cortical excitability threshold can be increased by the AMPA blocker Perampanel in amyotrophic lateral sclerosis. Muscle Nerve 2021; 64:215-219. [PMID: 34008857 DOI: 10.1002/mus.27328] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 05/09/2021] [Accepted: 05/16/2021] [Indexed: 11/07/2022]
Abstract
INTRODUCTION/AIMS Cortical hyperexcitability is a feature of amyotrophic lateral sclerosis (ALS) and cortical excitability can be measured using transcranial magnetic stimulation (TMS). Resting motor threshold (MT) is a measure of cortical excitability, largely driven by glutamate. Perampanel, a glutamate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor blocker, is predicted to increase the cortical excitability threshold. This study aimed to evaluate TMS to functionally assess target engagement in a study of perampanel in ALS. METHOD We studied the MT of ALS patients randomized to a single dose of perampanel or placebo 5:1 hourly for 4 h. Twelve patients participated at 4 mg and 7 returned for dosing and retesting at 8 mg. The study was terminated in April 2020 due to coronavirus disease 2019-related restrictions, after 7 out of 12 planned patients had received the 8 mg dose. Serum concentrations were also measured. RESULTS Ten patients received the 4 mg dose (2 received placebo) and 5 received the 8 mg dose (2 received placebo). Motor Threshold increased at 2 h after dosing in the combined treatment group +7% of maximal stimulator output (P < .01). Change could be detected in the larger 4 mg group (P = .02), but not in the smaller 8 mg dose group (P = .1). No side effects were reported after single dose exposure. DISCUSSION This study shows that perampanel effects the physiology of upper motor neurons. Studies aiming at gauging the effect of perampanel on ALS disease progression are already ongoing. Motor threshold may serve as a marker of biological target engagement.
Collapse
Affiliation(s)
- Björn Oskarsson
- Florida Department of Neurology, Mayo Clinic, Jacksonville, Florida, USA
| | | | - Jaimin S Shah
- Florida Department of Neurology, Mayo Clinic, Jacksonville, Florida, USA
| | - Zhuo Li
- Florida Department of Biostatistics, Mayo Clinic, Jacksonville, Florida, USA
| | - Michael A Rogawski
- Departments of Neurology and Pharmacology, University of California, Davis, California, USA
| |
Collapse
|
44
|
Clerke JA, Congiu M, Mameli M. Neuronal adaptations in the lateral habenula during drug withdrawal: Preclinical evidence for addiction therapy. Neuropharmacology 2021; 192:108617. [PMID: 34019906 DOI: 10.1016/j.neuropharm.2021.108617] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/14/2021] [Accepted: 05/11/2021] [Indexed: 12/14/2022]
Abstract
The epithalamic lateral habenula (LHb) regulates monoaminergic systems and contributes to the expression of both appetitive and aversive behaviours. Over the past years, the LHb has emerged as a vulnerable brain structure in mental illnesses including addiction. Behavioural and functional evidence in humans and rodents provide substantial support for a role of LHb in the negative affective symptoms emerging during withdrawal from addictive substances. Multiple forms of cellular and synaptic adaptations that take hold during drug withdrawal within the LHb are causally linked with the emergence of negative affective symptoms. These results indicate that targeting drug withdrawal-driven adaptations in the LHb may represent a potential strategy to normalize drug-related behavioural adaptations. In the current review we describe the mechanisms leading to functional alterations in the LHb, as well as the existing interventions used to counteract addictive behaviours. Finally, closing this loop we discuss and propose new avenues to potentially target the LHb in humans in light of the mechanistic understanding stemming from pre-clinical studies. Altogether, we provide an overview on how to leverage cellular-level understanding to envision clinically-relevant approaches for the treatment of specific aspects in drug addiction.
Collapse
Affiliation(s)
- Joseph A Clerke
- The Department of Fundamental Neuroscience, The University of Lausanne, 1005, Lausanne, Switzerland
| | - Mauro Congiu
- The Department of Fundamental Neuroscience, The University of Lausanne, 1005, Lausanne, Switzerland
| | - Manuel Mameli
- The Department of Fundamental Neuroscience, The University of Lausanne, 1005, Lausanne, Switzerland; Inserm, UMR-S 839, 75005, Paris, France.
| |
Collapse
|
45
|
Opie GM, Liao WY, Semmler JG. Interactions Between Cerebellum and the Intracortical Excitatory Circuits of Motor Cortex: a Mini-Review. CEREBELLUM (LONDON, ENGLAND) 2021; 21:159-166. [PMID: 33978934 DOI: 10.1007/s12311-021-01278-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Accepted: 05/03/2021] [Indexed: 12/28/2022]
Abstract
Interactions between cerebellum (CB) and primary motor cortex (M1) are critical for effective motor function. Although the associated neurophysiological processes are yet to be fully characterised, a growing body of work using non-invasive brain stimulation (NIBS) techniques has significantly progressed our current understanding. In particular, recent developments with both transcranial magnetic (TMS) and direct current (tDCS) stimulation suggest that CB modulates the activity of local excitatory interneuronal circuits within M1. These circuits are known to be important both physiologically and functionally, and understanding the nature of their connectivity with CB therefore has the potential to provide important insight for NIBS applications. Consequently, this mini-review provides an overview of the emerging literature that has investigated interactions between CB and the intracortical excitatory circuits of M1.
Collapse
Affiliation(s)
- George M Opie
- Discipline of Physiology, Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, 5005, Australia
| | - Wei-Yeh Liao
- Discipline of Physiology, Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, 5005, Australia
| | - John G Semmler
- Discipline of Physiology, Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, 5005, Australia.
| |
Collapse
|
46
|
Leukel C, Kurz A. Determining the types of descending waves from transcranial magnetic stimulation measured with conditioned H-reflexes in humans. Eur J Neurosci 2021; 54:5038-5046. [PMID: 33966324 DOI: 10.1111/ejn.15308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 04/09/2021] [Accepted: 05/02/2021] [Indexed: 11/30/2022]
Abstract
Non-invasive techniques are scarce with which human (motor) cortical mechanisms can be investigated. In a series of previous experiments, we have applied an advanced form of conditioning technique with transcranial magnetic stimulation (TMS) and peripheral nerve stimulation by which excitability changes at the laminar level in the primary motor cortex can be estimated. This method builds on the assumption that the first of subsequent corticospinal waves from TMS which is assessed with H-reflexes (called early facilitation) results from indirect excitation of corticospinal neurons in motor cortex (I-wave) and not direct excitation of corticospinal axons (D-wave). So far, we have not provided strong experimental evidence that this is actually the case. In the present study, we therefore compared temporal differences of the early facilitation between transcranial magnetic and electrical stimulation (TES). TES is known to excite the axons of corticospinal neurons. TES in our study caused a temporal shift of the early facilitation of H-reflexes in all subjects compared to TMS, which indicates that the early facilitation with TMS is indeed produced by an I-wave. Additionally, we investigated temporal shifts of the early facilitation with different TMS intensities and two TMS coils. It has long been known that TMS with higher intensities can induce a D-wave. Accordingly, we found that TMS with an intensity of 150% of resting motor threshold compared to 130%/110% results in a temporal shift of the early facilitation, indicating the presence of a D-wave. This effect was dependent on the coil type.
Collapse
Affiliation(s)
- Christian Leukel
- Department of Sport Science, University of Freiburg, Freiburg, Germany.,Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Alexander Kurz
- Department of Sport Science, University of Freiburg, Freiburg, Germany.,Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
| |
Collapse
|
47
|
Van Hoornweder S, Debeuf R, Verstraelen S, Meesen R, Cuypers K. Unravelling Ipsilateral Interactions Between Left Dorsal Premotor and Primary Motor Cortex: A Proof of Concept Study. Neuroscience 2021; 466:36-46. [PMID: 33971265 DOI: 10.1016/j.neuroscience.2021.04.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 04/28/2021] [Accepted: 04/29/2021] [Indexed: 11/16/2022]
Abstract
Few studies have identified the intrahemispheric functional connectivity between the ipsilateral dorsal premotor cortex (PMd) and the primary motor hand area (M1hand) due to technical limitations. In this proof-of-concept study, a novel neuronavigated dsTMS set-up was employed, combining stimulation over left PMd and left M1hand using the edge of a butterfly coil and a small cooled-coil. This arrangement was warranted because coil (over)heating and inter coil distance are limiting factors when investigating connectivity between stimulation targets in close proximity and over a longer duration. The proposed set-up was designed to deal with these limitations. Specifically, the effect of four dual-site transcranial magnetic stimulation (dsTMS) protocols on twenty-eight right-handed participants (12 males) was evaluated. These protocols differed in stimulus order, interstimulus interval and current direction induced in PMd. A structural scan with electric (E-)field modeling was obtained from seven participants prior to dsTMS, demonstrating that PMd and M1hand were effectively stimulated. Results indicate that one protocol, in which a latero-medial current was induced in PMd 2.8 ms prior to stimulation over M1hand, induced a sex-mediated effect. In males, significant inhibition of motor-evoked potentials was identified, whereas females demonstrated a facilitatory effect that did not survive correction for multiple comparisons. E-field simulations revealed that the E-field induced by the coil targeting PMd was maximal in PMd, with weaker E-field strengths extending to regions beyond PMd. Summarizing, the current dsTMS set-up enabled stimulating at an inter-target distance of 35 mm without any indications of coil-overheating.
Collapse
Affiliation(s)
- Sybren Van Hoornweder
- Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek, Belgium; Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Heverlee, Belgium
| | - Ruben Debeuf
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Heverlee, Belgium; Rehabilitation Research Group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Stefanie Verstraelen
- Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek, Belgium
| | - Raf Meesen
- Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek, Belgium
| | - Koen Cuypers
- Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, Diepenbeek, Belgium; Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Heverlee, Belgium.
| |
Collapse
|
48
|
Bergmann TO, Varatheeswaran R, Hanlon CA, Madsen KH, Thielscher A, Siebner HR. Concurrent TMS-fMRI for causal network perturbation and proof of target engagement. Neuroimage 2021; 237:118093. [PMID: 33940146 DOI: 10.1016/j.neuroimage.2021.118093] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/06/2021] [Accepted: 04/14/2021] [Indexed: 12/12/2022] Open
Abstract
The experimental manipulation of neural activity by neurostimulation techniques overcomes the inherent limitations of correlative recordings, enabling the researcher to investigate causal brain-behavior relationships. But only when stimulation and recordings are combined, the direct impact of the stimulation on neural activity can be evaluated. In humans, this can be achieved non-invasively through the concurrent combination of transcranial magnetic stimulation (TMS) with functional magnetic resonance imaging (fMRI). Concurrent TMS-fMRI allows the assessment of the neurovascular responses evoked by TMS with excellent spatial resolution and full-brain coverage. This enables the functional mapping of both local and remote network effects of TMS in cortical as well as deep subcortical structures, offering unique opportunities for basic research and clinical applications. The purpose of this review is to introduce the reader to this powerful tool. We will introduce the technical challenges and state-of-the art solutions and provide a comprehensive overview of the existing literature and the available experimental approaches. We will highlight the unique insights that can be gained from concurrent TMS-fMRI, including the state-dependent assessment of neural responsiveness and inter-regional effective connectivity, the demonstration of functional target engagement, and the systematic evaluation of stimulation parameters. We will also discuss how concurrent TMS-fMRI during a behavioral task can help to link behavioral TMS effects to changes in neural network activity and to identify peripheral co-stimulation confounds. Finally, we will review the use of concurrent TMS-fMRI for developing TMS treatments of psychiatric and neurological disorders and suggest future improvements for further advancing the application of concurrent TMS-fMRI.
Collapse
Affiliation(s)
- Til Ole Bergmann
- Neuroimaging Center (NIC), Focus Program Translational Neuroscience (FTN), Johannes Gutenberg University Medical Center, Langenbeckstr. 1, 55131, Mainz, Germany; Leibniz Institute for Resilience Research, Wallstraße 7-9, 55122, Mainz, Germany.
| | - Rathiga Varatheeswaran
- Neuroimaging Center (NIC), Focus Program Translational Neuroscience (FTN), Johannes Gutenberg University Medical Center, Langenbeckstr. 1, 55131, Mainz, Germany; Leibniz Institute for Resilience Research, Wallstraße 7-9, 55122, Mainz, Germany
| | - Colleen A Hanlon
- Department of Cancer Biology, Wake Forest School of Medicine, 1 Medical Center Blvd., Winston-Salem, NC 27157, USA
| | - Kristoffer H Madsen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Kettegård Allé 30, 2650, Hvidovre, Denmark; Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Axel Thielscher
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Kettegård Allé 30, 2650, Hvidovre, Denmark; Department of Electrical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Kettegård Allé 30, 2650, Hvidovre, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg, Bispebjerg Bakke 23, 2400 København NV, Denmark; Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| |
Collapse
|
49
|
TMS-EEG signatures of glutamatergic neurotransmission in human cortex. Sci Rep 2021; 11:8159. [PMID: 33854132 PMCID: PMC8047018 DOI: 10.1038/s41598-021-87533-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 03/24/2021] [Indexed: 12/13/2022] Open
Abstract
Neuronal activity in the brain reflects an excitation-inhibition balance that is regulated predominantly by glutamatergic and GABAergic neurotransmission, and often disturbed in neuropsychiatric disorders. Here, we tested the effects of a single oral dose of two anti-glutamatergic drugs (dextromethorphan, an NMDA receptor antagonist; perampanel, an AMPA receptor antagonist) and an L-type voltage-gated calcium channel blocker (nimodipine) on transcranial magnetic stimulation (TMS)-evoked electroencephalographic (EEG) potentials (TEPs) and TMS-induced oscillations (TIOs) in 16 healthy adults in a pseudorandomized, double-blinded, placebo-controlled crossover design. Single-pulse TMS was delivered to the hand area of left primary motor cortex. Dextromethorphan increased the amplitude of the N45 TEP, while it had no effect on TIOs. Perampanel reduced the amplitude of the P60 TEP in the non-stimulated hemisphere, and increased TIOs in the beta-frequency band in the stimulated sensorimotor cortex, and in the alpha-frequency band in midline parietal channels. Nimodipine and placebo had no effect on TEPs and TIOs. The TEP results extend previous pharmaco-TMS-EEG studies by demonstrating that the N45 is regulated by a balance of GABAAergic inhibition and NMDA receptor-mediated glutamatergic excitation. In contrast, AMPA receptor-mediated glutamatergic neurotransmission contributes to propagated activity reflected in the P60 potential and midline parietal induced oscillations. This pharmacological characterization of TMS-EEG responses will be informative for interpreting TMS-EEG abnormalities in neuropsychiatric disorders with pathological excitation-inhibition balance.
Collapse
|
50
|
Thorstensen JR, Taylor JL, Kavanagh JJ. Human corticospinal-motoneuronal output is reduced with 5-HT 2 receptor antagonism. J Neurophysiol 2021; 125:1279-1288. [PMID: 33596722 DOI: 10.1152/jn.00698.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Animal models indicate that serotonin (5-HT) release onto motoneurons facilitates motor output, particularly during strong motor activities. However, evidence for 5-HT effects during human movement are limited. This study examined how antagonism of the 5-HT2 receptor, which is a 5-HT receptor that promotes motoneuron excitability, affects human movement. Ten healthy participants (24.2 ± 1.9 yr) ingested 8 mg of cyproheptadine (competitive 5-HT2 antagonist) in a double-blinded, placebo-controlled, repeated-measures design. Transcranial magnetic stimulation (TMS) of the motor cortex was used to elicit motor evoked potentials (MEPs) from biceps brachii. First, stimulus-response curves (90%-160% active motor threshold) were obtained during very weak elbow flexions (10% of maximal). Second, to determine if 5-HT effects are scaled to the intensity of muscle contraction, TMS at a fixed intensity was applied during elbow flexions of 20%, 40%, 60%, 80%, and 100% of maximal. Cyproheptadine reduced the size of MEPs across the stimulus-response curves (P = 0.045). Notably, MEP amplitude was 22.3% smaller for the cyproheptadine condition for the strongest TMS intensity. In addition, cyproheptadine reduced maximal torque (P = 0.045), lengthened the biceps silent period during maximal elbow flexions (P = 0.037), and reduced superimposed twitch amplitude during moderate-intensity elbow flexions (P = 0.035). This study presents novel evidence that 5-HT2 receptors influence corticospinal-motoneuronal output, which was particularly evident when a large number of descending inputs to motoneurons were active. Although it is likely that antagonism of 5-HT2 receptors reduces motoneuron gain to ionotropic inputs, supraspinal mechanisms may have also contributed to the study findings.NEW & NOTEWORTHY Voluntary contractions and responses to magnetic stimulation of the motor cortex are dependent on serotonin activity in the central nervous system. 5-HT2 antagonism decreased evoked potential size to high-intensity stimulation, and reduced torque and lengthened inhibitory silent periods during maximal contractions. We provide novel evidence that 5-HT2 receptors are involved in muscle activation, where 5-HT effects are strongest when a large number of descending inputs activate motoneurons.
Collapse
Affiliation(s)
- Jacob R Thorstensen
- Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - Janet L Taylor
- School of Medical and Health Sciences, Edith Cowan University, Perth, Western Australia, Australia.,Neuroscience Research Australia (NeuRA), Sydney, New South Wales, Australia
| | - Justin J Kavanagh
- Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| |
Collapse
|