Pain-motor integration in chronic pain: A neurophysiological study

Francesco Asci; Giulia Di Stefano; Alessandro Di Santo; Edoardo Bianchini; Caterina Leone; Silvia La Cesa; Alessandro Zampogna; Giorgio Cruccu; Antonio Suppa

doi:10.1016/j.clinph.2023.07.010

Pain-motor integration in chronic pain: A neurophysiological study

Clin Neurophysiol. 2023 Oct:154:107-115. doi: 10.1016/j.clinph.2023.07.010. Epub 2023 Aug 7.

Authors

Francesco Asci¹, Giulia Di Stefano², Alessandro Di Santo³, Edoardo Bianchini⁴, Caterina Leone⁵, Silvia La Cesa⁶, Alessandro Zampogna⁷, Giorgio Cruccu⁸, Antonio Suppa⁹

Affiliations

¹ Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185 Rome, Italy; IRCCS Neuromed Institute, Via Atinense, 18, 86077 Pozzilli, IS, Italy. Electronic address: francesco.asci@uniroma1.it.
² Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185 Rome, Italy. Electronic address: giulia.distefano@uniroma1.it.
³ Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Università Campus Bio-Medico di Roma, Via Álvaro del Portillo 21, 00128 Rome, Italy. Electronic address: alessandro.disanto@hotmail.com.
⁴ Department of Neuroscience, Mental Health and Sense Organs (NESMOS), Sapienza University of Rome, Via di Grottarossa 1035-1039, 00189 Rome, Italy. Electronic address: edoardo.bianchini@uniroma1.it.
⁵ Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185 Rome, Italy. Electronic address: caterina.leone@uniroma1.it.
⁶ Unit of Neurology, S. Camillo-Forlanini Hospital, Rome, Italy. Electronic address: slacesa@scamilloforlanini.rm.it.
⁷ Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185 Rome, Italy. Electronic address: alessandro.zampogna@uniroma1.it.
⁸ Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185 Rome, Italy. Electronic address: giorgio.cruccu@uniroma1.it.
⁹ Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università, 30, 00185 Rome, Italy; IRCCS Neuromed Institute, Via Atinense, 18, 86077 Pozzilli, IS, Italy. Electronic address: antonio.suppa@uniroma1.it.

PMID: 37595480
DOI: 10.1016/j.clinph.2023.07.010

Abstract

Objective: Chronic pain may lead to functional changes in several brain regions, including the primary motor cortex (M1). Our neurophysiological study aimed to probe M1 plasticity, through a non-invasive transcranial magnetic stimulation protocol, in a cohort of patients with chronic pain.

Methods: Twenty patients with chronic pain (age ± SD: 62.9 ± 9.9) and 20 age- and sex-matched healthy controls (age ± SD: 59.6 ± 15.8) were recruited. Standardized scales were used for the evaluation of pain severity. Neurophysiological measures included laser-evoked potentials (LEPs) and motor-evoked potentials (MEPs) collected at baseline and over 60 minutes following a standardized Laser-paired associative stimulation (Laser-PAS) protocol.

Results: LEPs and MEPs were comparable in patients with chronic pain and controls. The pain threshold was lower in patients than in controls. Laser-PAS elicited decreased responses in patients with chronic pain. The response to Laser-PAS was similar in subgroups of patients with different chronic pain phenotypes.

Conclusions: M1 plasticity, as tested by Laser-PAS, is altered in patients with chronic pain, possibly reflecting abnormal pain-motor integration processes.

Significance: Chronic pain is associated with a disorder of M1 plasticity raising from abnormal pain-motor integration.

Keywords: Chronic pain; Laser-evoked potentials; Pain-motor integration; Paired associative stimulation; Primary motor cortex.

MeSH terms

Chronic Pain* / diagnosis
Evoked Potentials, Motor / physiology
Humans
Motor Cortex*
Neuronal Plasticity / physiology
Pain Threshold
Transcranial Magnetic Stimulation / methods