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Antonioni A, Raho EM, Straudi S, Granieri E, Koch G, Fadiga L. The cerebellum and the Mirror Neuron System: A matter of inhibition? From neurophysiological evidence to neuromodulatory implications. A narrative review. Neurosci Biobehav Rev 2024; 164:105830. [PMID: 39069236 DOI: 10.1016/j.neubiorev.2024.105830] [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: 06/09/2024] [Revised: 07/20/2024] [Accepted: 07/24/2024] [Indexed: 07/30/2024]
Abstract
Mirror neurons show activity during both the execution (AE) and observation of actions (AO). The Mirror Neuron System (MNS) could be involved during motor imagery (MI) as well. Extensive research suggests that the cerebellum is interconnected with the MNS and may be critically involved in its activities. We gathered evidence on the cerebellum's role in MNS functions, both theoretically and experimentally. Evidence shows that the cerebellum plays a major role during AO and MI and that its lesions impair MNS functions likely because, by modulating the activity of cortical inhibitory interneurons with mirror properties, the cerebellum may contribute to visuomotor matching, which is fundamental for shaping mirror properties. Indeed, the cerebellum may strengthen sensory-motor patterns that minimise the discrepancy between predicted and actual outcome, both during AE and AO. Furthermore, through its connections with the hippocampus, the cerebellum might be involved in internal simulations of motor programs during MI. Finally, as cerebellar neuromodulation might improve its impact on MNS activity, we explored its potential neurophysiological and neurorehabilitation implications.
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Affiliation(s)
- Annibale Antonioni
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara 44121, Italy; Department of Neuroscience, Ferrara University Hospital, Ferrara 44124, Italy; Doctoral Program in Translational Neurosciences and Neurotechnologies, University of Ferrara, Ferrara 44121, Italy.
| | - Emanuela Maria Raho
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara 44121, Italy
| | - Sofia Straudi
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara 44121, Italy; Department of Neuroscience, Ferrara University Hospital, Ferrara 44124, Italy
| | - Enrico Granieri
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara 44121, Italy
| | - Giacomo Koch
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara 44121, Italy; Center for Translational Neurophysiology of Speech and Communication (CTNSC), Italian Institute of Technology (IIT), Ferrara 44121 , Italy; Non Invasive Brain Stimulation Unit, Istituto di Ricovero e Cura a Carattere Scientifico Santa Lucia, Rome 00179, Italy
| | - Luciano Fadiga
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara 44121, Italy; Center for Translational Neurophysiology of Speech and Communication (CTNSC), Italian Institute of Technology (IIT), Ferrara 44121 , Italy
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Wilhelm E, Derosiere G, Quoilin C, Cakiroglu I, Paço S, Raftopoulos C, Nuttin B, Duque J. Subthalamic DBS does not restore deficits in corticospinal suppression during movement preparation in Parkinson's disease. Clin Neurophysiol 2024; 165:107-116. [PMID: 38996612 DOI: 10.1016/j.clinph.2024.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 03/27/2024] [Accepted: 06/03/2024] [Indexed: 07/14/2024]
Abstract
OBJECTIVE Parkinson's disease (PD) patients exhibit changes in mechanisms underlying movement preparation, particularly the suppression of corticospinal excitability - termed "preparatory suppression" - which is thought to facilitate movement execution in healthy individuals. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) being an attractive treatment for advanced PD, we aimed to study the potential contribution of this nucleus to PD-related changes in such corticospinal dynamics. METHODS On two consecutive days, we applied single-pulse transcranial magnetic stimulation to the primary motor cortex of 20 advanced PD patients treated with bilateral STN-DBS (ON vs. OFF), as well as 20 healthy control subjects. Motor-evoked potentials (MEPs) were elicited at rest or during movement preparation in an instructed-delay choice reaction time task including left- or right-hand responses. Preparatory suppression was assessed by expressing MEPs during movement preparation relative to rest. RESULTS PD patients exhibited a deficit in preparatory suppression when it was probed on the responding hand side, particularly when this corresponded to their most-affected hand, regardless of their STN-DBS status. CONCLUSIONS Advanced PD patients displayed a reduction in preparatory suppression which was not restored by STN-DBS. SIGNIFICANCE The current findings confirm that PD patients lack preparatory suppression, as previously reported. Yet, the fact that this deficit was not responsive to STN-DBS calls for future studies on the neural source of this regulatory mechanism during movement preparation.
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Affiliation(s)
- Emmanuelle Wilhelm
- Institute of Neuroscience, Catholic University of Louvain, 1200 Brussels, Belgium; Department of Adult Neurology, Saint-Luc University Hospital, 1200 Brussels, Belgium.
| | - Gerard Derosiere
- Institute of Neuroscience, Catholic University of Louvain, 1200 Brussels, Belgium
| | - Caroline Quoilin
- Institute of Neuroscience, Catholic University of Louvain, 1200 Brussels, Belgium
| | - Inci Cakiroglu
- Institute of Neuroscience, Catholic University of Louvain, 1200 Brussels, Belgium
| | - Susana Paço
- NOVA IMS, Universidade Nova de Lisboa, 1070-312 Lisbon, Portugal
| | | | - Bart Nuttin
- Department of Neurosurgery, UZ Leuven, 3000 Leuven, Belgium
| | - Julie Duque
- Institute of Neuroscience, Catholic University of Louvain, 1200 Brussels, Belgium
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Bakken K, Horton C, Fisher M, Wadsley CG, Greenhouse I. Corticospinal excitability at rest outside of a task does not differ from task intertrial intervals in healthy adults. Exp Brain Res 2024; 242:2263-2270. [PMID: 39043898 DOI: 10.1007/s00221-024-06895-8] [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: 01/24/2024] [Accepted: 07/10/2024] [Indexed: 07/25/2024]
Abstract
Human corticospinal excitability (CSE) modulates during movement, when muscles are active, but also at rest, when muscles are not active. These changes in resting motor system excitability can be transient or longer lasting. Evidence from transcranial magnetic stimulation (TMS) studies suggests even relatively short periods of motor learning on the order of minutes can have lasting effects on resting CSE. Whether individuals are able to return CSE to out-of-task resting levels during the intertrial intervals (ITI) of behavioral tasks that do not include an intended motor learning component is an important question. Here, in twenty-five healthy young adults, we used single-pulse TMS and electromyography (EMG) to measure motor evoked potentials (MEPs) during two different resting contexts: (1) prior to engaging in the response task during which participants were instructed only to rest (out-of-task), and (2) ITI of a choice-reaction time task (in-task). In both contexts, five TMS intensities were used to evaluate possible differences in recruitment of corticospinal (CS) output across a range of inputs. We hypothesized resting state CSE would be greater during ITI than out-of-task rest, reflected in larger MEP amplitudes. Contrary to our hypothesis, we observed no significant difference in MEP amplitudes between out-of-task rest and in-task ITI, and instead found evidence of equivalence, indicating that humans are able to return to a stable motor resting state within seconds after a response. These data support the interpretation that rest is a uniform motor state in the healthy nervous system. In the future, our data may be a useful reference for motor disorder populations with an impaired ability to return to rest.
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Affiliation(s)
- Kate Bakken
- Action Control Lab, Department of Human Physiology, University of Oregon, Eugene, OR, USA
| | - Chris Horton
- Action Control Lab, Department of Human Physiology, University of Oregon, Eugene, OR, USA
| | - Mitchell Fisher
- Action Control Lab, Department of Human Physiology, University of Oregon, Eugene, OR, USA
| | - Corey G Wadsley
- Action Control Lab, Department of Human Physiology, University of Oregon, Eugene, OR, USA
| | - Ian Greenhouse
- Action Control Lab, Department of Human Physiology, University of Oregon, Eugene, OR, USA.
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Wadsley CG, Nguyen T, Horton C, Greenhouse I. Goal-directed action preparation in humans entails a mixture of corticospinal neural computations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.08.602530. [PMID: 39026882 PMCID: PMC11257418 DOI: 10.1101/2024.07.08.602530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
The seemingly effortless ability of humans to transition from thinking about actions to initiating them relies on sculpting corticospinal output from primary motor cortex. This study tested whether canonical additive and multiplicative neural computations, well-described in sensory systems, generalize to the corticospinal pathway during human action preparation. We used non-invasive brain stimulation to measure corticospinal input-output across varying action preparation contexts during instructed-delay finger response tasks. Goal-directed action preparation was marked by increased multiplicative gain of corticospinal projections to task-relevant muscles and additive suppression of corticospinal projections to non-selected and task-irrelevant muscles. Individuals who modulated corticospinal gain to a greater extent were faster to initiate prepared responses. Our findings provide physiological evidence of combined additive suppression and gain modulation in the human motor system. We propose these computations support action preparation by enhancing the contrast between selected motor representations and surrounding background activity to facilitate response selection and execution.
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Affiliation(s)
- Corey G. Wadsley
- Action Control Lab, Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
- Institute of Neuroscience, University of Oregon, Eugene, Oregon, USA
| | - Thuan Nguyen
- School of Public Health, Portland State University-Oregon Health and Science University, Portland, Oregon, USA
| | - Chris Horton
- Action Control Lab, Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Ian Greenhouse
- Action Control Lab, Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
- Institute of Neuroscience, University of Oregon, Eugene, Oregon, USA
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Hamel R, Waltzing BM, Hinder MR, McAllister CJ, Jenkinson N, Galea JM. Bilateral intracortical inhibition during unilateral motor preparation and sequence learning. Brain Stimul 2024; 17:349-361. [PMID: 38479713 DOI: 10.1016/j.brs.2024.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 02/23/2024] [Accepted: 03/06/2024] [Indexed: 03/22/2024] Open
Abstract
Motor sequence learning gradually quickens reaction time, suggesting that sequence learning alters motor preparation processes. Interestingly, evidence has shown that preparing sequence movements decreases short intracortical inhibition (SICI) in the contralateral motor cortex (M1), but also that sequence learning alters motor preparation processes in both the contralateral and ipsilateral M1s. Therefore, one possibility is that sequence learning alters the SICI decreases occurring during motor preparation in bilateral M1s. To examine this, two novel hypotheses were tested: unilateral sequence preparation would decrease SICI in bilateral M1s, and sequence learning would alter such bilateral SICI responses. Paired-pulse transcranial magnetic stimulation was delivered over the contralateral and ipsilateral M1s to assess SICI in an index finger muscle during the preparation of sequences initiated by either the right index or little finger. In the absence of sequence learning, SICI decreased in both the contralateral and ipsilateral M1s during the preparation of sequences initiated by the right index finger, suggesting that SICI decreases in bilateral M1s during unilateral motor preparation. As sequence learning progressed, SICI decreased in the contralateral M1 whilst it increased in the ipsilateral M1. Moreover, these bilateral SICI responses were observed at the onset of motor preparation, suggesting that sequence learning altered baseline SICI levels rather than the SICI decreases occurring during motor preparation per se. Altogether, these results suggest that SICI responses in bilateral M1s reflect two motor processes: an acute decrease of inhibition during motor preparation, and a cooperative but bidirectional shift of baseline inhibition levels as sequence learning progresses.
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Affiliation(s)
- R Hamel
- School of Sports, Exercise, and Rehabilitation Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom; School of Psychology and Centre for Human Brain Health, University of Birmingham, Birmingham, B15 2TT, United Kingdom.
| | - B M Waltzing
- School of Sports, Exercise, and Rehabilitation Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom; Institute of Neurosciences, UC Louvain, Belgium Avenue Mounier 54, 1200, Bruxelles, Belgium
| | - M R Hinder
- School of Psychological Sciences, College of Health and Medicine After School of Psychological Sciences, University of Tasmania, Hobart, Australia
| | - C J McAllister
- School of Sports, Exercise, and Rehabilitation Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - N Jenkinson
- School of Sports, Exercise, and Rehabilitation Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - J M Galea
- School of Psychology and Centre for Human Brain Health, University of Birmingham, Birmingham, B15 2TT, United Kingdom
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Quoilin C, Chaise F, Duque J, de Timary P. Relationship between transcranial magnetic stimulation markers of motor control and clinical recovery in obsessive compulsive disorder/Gilles de la Tourette syndrome: a proof of concept case study. Front Psychiatry 2024; 15:1307344. [PMID: 38304284 PMCID: PMC10832049 DOI: 10.3389/fpsyt.2024.1307344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 01/04/2024] [Indexed: 02/03/2024] Open
Abstract
Background Obsessive compulsive disorder (OCD) and Gilles de la Tourette syndrome (GTS) are neurodevelopmental disorders characterized by difficulties in controlling intrusive thoughts (obsessions) and undesired actions (tics), respectively. Both conditions have been associated with abnormal inhibition but a tangible deficit of inhibitory control abilities is controversial in GTS. Methods Here, we examined a 25 years-old male patient with severe OCD symptoms and a mild form of GTS, where impairments in motor control were central. Transcranial magnetic stimulation (TMS) was applied over the primary motor cortex (M1) to elicit motor-evoked potentials (MEPs) during four experimental sessions, allowing us to assess the excitability of motor intracortical circuitry at rest as well as the degree of MEP suppression during action preparation, a phenomenon thought to regulate movement initiation. Results When tested for the first time, the patient presented a decent level of MEP suppression during action preparation, but he exhibited a lack of intracortical inhibition at rest, as evidenced by reduced short-interval intracortical inhibition (SICI) and long-interval intracortical inhibition (LICI). Interestingly, the patient's symptomatology drastically improved over the course of the sessions (reduced obsessions and tics), coinciding with feedback given on his good motor control abilities. These changes were reflected in the TMS measurements, with a significant strengthening of intracortical inhibition (SICI and LICI more pronounced than previously) and a more selective tuning of MEPs during action preparation; MEPs became even more suppressed, or selectively facilitated depending on the behavioral condition in which they we probed. Conclusion This study highlights the importance of better understanding motor inhibitory mechanisms in neurodevelopmental disorders and suggests a biofeedback approach as a potential novel treatment.
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Affiliation(s)
- Caroline Quoilin
- CoActions Lab, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Fostine Chaise
- CoActions Lab, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Julie Duque
- CoActions Lab, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Philippe de Timary
- CoActions Lab, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
- Department of Adult Psychiatry, Cliniques universitaires Saint-Luc, Brussels, Belgium
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7
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Hamel R, Pearson J, Sifi L, Patel D, Hinder MR, Jenkinson N, Galea JM. The intracortical excitability changes underlying the enhancing effects of rewards and punishments on motor performance. Brain Stimul 2023; 16:1462-1475. [PMID: 37777109 DOI: 10.1016/j.brs.2023.09.022] [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: 03/28/2023] [Revised: 09/13/2023] [Accepted: 09/18/2023] [Indexed: 10/02/2023] Open
Abstract
Monetary rewards and punishments enhance motor performance and are associated with corticospinal excitability (CSE) increases within the motor cortex (M1) during movement preparation. However, such CSE changes have unclear origins. Based on converging evidence, one possibility is that they stem from increased glutamatergic (GLUTergic) facilitation and/or decreased type A gamma-aminobutyric acid (GABAA)-mediated inhibition within M1. To investigate this, paired-pulse transcranial magnetic stimulation was used over the left M1 to evaluate intracortical facilitation (ICF) and short intracortical inhibition (SICI), indirect assays of GLUTergic activity and GABAA-mediated inhibition, in an index finger muscle during the preparation of sequences initiated by either the right index or little finger. Behaviourally, rewards and punishments enhanced both reaction and movement time. During movement preparation, regardless of rewards or punishments, ICF increased when the index finger initiated sequences, whereas SICI decreased when both the index and little fingers initiated sequences. This finding suggests that GLUTergic activity increases in a finger-specific manner whilst GABAA-mediated inhibition decreases in a finger-unspecific manner during preparation. In parallel, both rewards and punishments non-specifically increased ICF, but only rewards non-specifically decreased SICI as compared to neutral. This suggests that to enhance performance rewards both increase GLUTergic activity and decrease GABAA-mediated inhibition, whereas punishments selectively increase GLUTergic activity. A control experiment revealed that such changes were not observed post-movement as participants processed reward and punishment feedback, indicating they were selective to movement preparation. Collectively, these results map the intracortical excitability changes in M1 by which incentives enhance motor performance.
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Affiliation(s)
- R Hamel
- School of Psychology, University of Birmingham, Birmingham, B15 2TT, United Kingdom; School of Sport, Exercise, and Rehabilitation, University of Birmingham, Birmingham, B15 2TT, United Kingdom.
| | - J Pearson
- School of Psychology, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - L Sifi
- School of Psychology, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - D Patel
- School of Psychology, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - M R Hinder
- School of Psychological Sciences, University of Tasmania, Hobart, Australia
| | - N Jenkinson
- School of Sport, Exercise, and Rehabilitation, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - J M Galea
- School of Psychology, University of Birmingham, Birmingham, B15 2TT, United Kingdom
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Nuara A, Bazzini MC, Cardellicchio P, Scalona E, De Marco D, Rizzolatti G, Fabbri-Destro M, Avanzini P. The value of corticospinal excitability and intracortical inhibition in predicting motor skill improvement driven by action observation. Neuroimage 2023; 266:119825. [PMID: 36543266 DOI: 10.1016/j.neuroimage.2022.119825] [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: 09/01/2022] [Revised: 12/15/2022] [Accepted: 12/17/2022] [Indexed: 12/23/2022] Open
Abstract
The observation of other's actions represents an essential element for the acquisition of motor skills. While action observation is known to induce changes in the excitability of the motor cortices, whether such modulations may explain the amount of motor improvement driven by action observation training (AOT) remains to be addressed. Using transcranial magnetic stimulation (TMS), we first assessed in 41 volunteers the effect of action observation on corticospinal excitability, intracortical inhibition, and transcallosal inhibition. Subsequently, half of the participants (AOT-group) were asked to observe and then execute a right-hand dexterity task, while the controls had to observe a no-action video before practicing the same task. AOT participants showed greater performance improvement relative to controls. More importantly, the amount of improvement in the AOT group was predicted by the amplitude of corticospinal modulation during action observation and, even more, by the amount of intracortical inhibition induced by action observation. These relations were specific for the AOT group, while the same patterns were not found in controls. Taken together, our findings demonstrate that the efficacy of AOT in promoting motor learning is rooted in the capacity of action observation to modulate the trainee's motor system excitability, especially its intracortical inhibition. Our study not only enriches the picture of the neurophysiological effects induced by action observation onto the observer's motor excitability, but linking them to the efficacy of AOT, it also paves the way for the development of models predicting the outcome of training procedures based on the observation of other's actions.
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Affiliation(s)
- Arturo Nuara
- CNR Neuroscience Institute, via Volturno 39/E, Parma 43125, Italy.
| | | | - Pasquale Cardellicchio
- IIT@UniFe Center for Translational Neurophysiology, Istituto Italiano di Tecnologia, Ferrara, Italy
| | - Emilia Scalona
- CNR Neuroscience Institute, via Volturno 39/E, Parma 43125, Italy; Specialità Medico-Chirurgiche, Scienze Radiologiche e Sanità Pubblica (DSMC), Università degli studi di Brescia, Italia
| | - Doriana De Marco
- CNR Neuroscience Institute, via Volturno 39/E, Parma 43125, Italy
| | | | | | - Pietro Avanzini
- CNR Neuroscience Institute, via Volturno 39/E, Parma 43125, Italy; Istituto Clinico Humanitas, Humanitas Clinical and Research Center, Milan, Rozzano, Italy
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Wilhelm E, Quoilin C, Derosiere G, Paço S, Jeanjean A, Duque J. Corticospinal Suppression Underlying Intact Movement Preparation Fades in Parkinson's Disease. Mov Disord 2022; 37:2396-2406. [PMID: 36121426 DOI: 10.1002/mds.29214] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/11/2022] [Accepted: 08/17/2022] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND In Parkinson's disease (PD), neurophysiological abnormalities within the primary motor cortex (M1) have been shown to contribute to bradykinesia, but exact modalities are still uncertain. We propose that such motor slowness could involve alterations in mechanisms underlying movement preparation, especially the suppression of corticospinal excitability-called "preparatory suppression"-which is considered to propel movement execution by increasing motor neural gain in healthy individuals. METHODS On two consecutive days, 29 PD patients (on and off medication) and 29 matched healthy controls (HCs) underwent transcranial magnetic stimulation over M1, eliciting motor-evoked potentials (MEPs) in targeted hand muscles, while they were either at rest or preparing a left- or right-hand response in an instructed-delay choice reaction time task. Preparatory suppression was assessed by expressing MEP amplitudes during movement preparation relative to rest. RESULTS Contrary to HCs, PD patients showed a lack of preparatory suppression when the side of the responding hand was analyzed, especially when the latter was the most affected one. This deficit, which did not depend on dopamine medication, increased with disease duration and also tended to correlate with motor impairment, as measured by the Movement Disorder Society Unified Parkinson's Disease Rating Scale, Part III (both total and bradykinesia scores). CONCLUSIONS Our novel findings indicate that preparatory suppression fades in PD, in parallel with worsening motor symptoms, including bradykinesia. Such results suggest that an alteration in this marker of intact movement preparation could indeed cause motor slowness and support its use in future studies on the relation between M1 alterations and motor impairment in PD. © 2022 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Emmanuelle Wilhelm
- CoActions Lab, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium.,Department of Adult Neurology, Saint-Luc University Hospital, Brussels, Belgium
| | - Caroline Quoilin
- CoActions Lab, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Gerard Derosiere
- CoActions Lab, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Susana Paço
- NOVA IMS, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Anne Jeanjean
- Department of Adult Neurology, Saint-Luc University Hospital, Brussels, Belgium
| | - Julie Duque
- CoActions Lab, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
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