Neural bases of motor fatigue in multiple sclerosis: A multimodal approach using neuromuscular assessment and TMS-EEG

Giorgio Leodori; Marco Mancuso; Davide Maccarrone; Matteo Tartaglia; Antonio Ianniello; Francesco Certo; Viola Baione; Gina Ferrazzano; Leonardo Malimpensa; Daniele Belvisi; Carlo Pozzilli; Alfredo Berardelli; Antonella Conte

Neurobiology of Disease (May 2023)

Neural bases of motor fatigue in multiple sclerosis: A multimodal approach using neuromuscular assessment and TMS-EEG

Giorgio Leodori,
Marco Mancuso,
Davide Maccarrone,
Matteo Tartaglia,
Antonio Ianniello,
Francesco Certo,
Viola Baione,
Gina Ferrazzano,
Leonardo Malimpensa,
Daniele Belvisi,
Carlo Pozzilli,
Alfredo Berardelli,
Antonella Conte

Affiliations

Giorgio Leodori: IRCCS Neuromed, Pozzilli (IS), Pozzilli 86077, Italy; Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
Marco Mancuso: Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
Davide Maccarrone: Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
Matteo Tartaglia: Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
Antonio Ianniello: Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy; Multiple Sclerosis Center, S. Andrea Hospital, Department of Neurology and Psychiatry, Sapienza University of Rome, Rome 00185, Italy
Francesco Certo: Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
Viola Baione: Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
Gina Ferrazzano: Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
Leonardo Malimpensa: Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
Daniele Belvisi: IRCCS Neuromed, Pozzilli (IS), Pozzilli 86077, Italy; Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
Carlo Pozzilli: Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy; Multiple Sclerosis Center, S. Andrea Hospital, Department of Neurology and Psychiatry, Sapienza University of Rome, Rome 00185, Italy
Alfredo Berardelli: IRCCS Neuromed, Pozzilli (IS), Pozzilli 86077, Italy; Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy
Antonella Conte: IRCCS Neuromed, Pozzilli (IS), Pozzilli 86077, Italy; Department of Human Neurosciences, Sapienza University of Rome, Rome 00185, Italy; Corresponding author at: Department of Human Neurosciences, Sapienza, University of Rome, Viale dell'Università, 30, Rome 00185, Italy.

Journal volume & issue: Vol. 180
p. 106073

Abstract

Read online

Motor fatigue is one of the most common symptoms in multiple sclerosis (MS) patients. Previous studies suggested that increased motor fatigue in MS may arise at the central nervous system level. However, the mechanisms underlying central motor fatigue in MS are still unclear.This paper investigated whether central motor fatigue in MS reflects impaired corticospinal transmission or suboptimal primary motor cortex (M1) output (supraspinal fatigue). Furthermore, we sought to identify whether central motor fatigue is associated with abnormal M1 excitability and connectivity within the sensorimotor network.Twenty-two patients affected by relapsing-remitting MS and 15 healthy controls (HCs) performed repeated blocks of contraction at different percentages of maximal voluntary contraction with the right first dorsal interosseus muscle until exhaustion. Peripheral, central, and supraspinal components of motor fatigue were quantified by a neuromuscular assessment based on the superimposed twitch evoked by peripheral nerve and transcranial magnetic stimulation (TMS). Corticospinal transmission, excitability and inhibition during the task were tested by measurement of motor evoked potential (MEP) latency, amplitude, and cortical silent period (CSP). M1 excitability and connectivity was measured by TMS-evoked electroencephalography (EEG) potentials (TEPs) elicited by M1 stimulation before and after the task.Patients completed fewer blocks of contraction and showed higher values of central and supraspinal fatigue than HCs. We found no MEP or CSP differences between MS patients and HCs. Patients showed a post-fatigue increase in TEPs propagation from M1 to the rest of the cortex and in source-reconstructed activity within the sensorimotor network, in contrast to the reduction observed in HCs. Post-fatigue increase in source-reconstructed TEPs correlated with supraspinal fatigue values.To conclude, MS-related motor fatigue is caused by central mechanisms related explicitly to suboptimal M1 output rather than impaired corticospinal transmission. Furthermore, by adopting a TMS-EEG approach, we proved that suboptimal M1 output in MS patients is associated with abnormal task-related modulation of M1 connectivity within the sensorimotor network. Our findings shed new light on the central mechanisms of motor fatigue in MS by highlighting a possible role of abnormal sensorimotor network dynamics. These novel results may point to new therapeutical targets for fatigue in MS.

Published in Neurobiology of Disease

ISSN: 0969-9961 (Print); 1095-953X (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Medicine: Internal medicine: Neurosciences. Biological psychiatry. Neuropsychiatry
Website: https://www.journals.elsevier.com/neurobiology-of-disease

About the journal

Abstract

Keywords