open access publication

Article, 2023

Corticomotor excitability is altered in central neuropathic pain compared with non-neuropathic pain or pain-free patients

In: Neurophysiologie Clinique, ISSN 0987-7053, 1769-7131, Volume 53, 3, Page 102845, 10.1016/j.neucli.2023.102845

Contributors (11)

Barbosa, Luciana Mendonça Morais (0000-0002-5239-5935) [1] Valerio, Fernanda (0000-0001-5248-7314) [1] Da Silva, Valquíria Aparecida (0000-0002-4113-1766) [1] Rodrigues, Antônia Lilian De Lima [1] Galhardoni, Ricardo R [1] Yeng, Lin Tchia (0000-0001-5810-6236) [1] Junior, Jefferson Rosi [1] Conforto, Adriana Bastos (0000-0001-7869-3490) [1] Lucato, Leandro Tavares (0000-0001-9181-5245) [1] Teixeira, Manoel Jacobsen (0000-0002-7974-6045) [1] De Andrade, Daniel Ciampi Araujo (0000-0003-3411-632X) (Corresponding author) [1] [2]


  1. [1] Universidade de São Paulo
  2. [NORA names: Brazil; America, South]
  3. [2] Aalborg University
  4. [NORA names: AAU Aalborg University; University; Denmark; Europe, EU; Nordic; OECD]


OBJECTIVES: Central neuropathic pain (CNP) is associated with altered corticomotor excitability (CE), which can potentially provide insights into its mechanisms. The objective of this study is to describe the CE changes that are specifically related to CNP. METHODS: We evaluated CNP associated with brain injury after stroke or spinal cord injury (SCI) due to neuromyelitis optica through a battery of CE measurements and comprehensive pain, neurological, functional, and quality of life assessments. CNP was compared to two groups of patients with the same disease: i. with non-neuropathic pain and ii. without chronic pain, matched by sex and lesion location. RESULTS: We included 163 patients (stroke=93; SCI=70: 74 had CNP, 43 had non-neuropathic pain, and 46 were pain-free). Stroke patients with CNP had lower motor evoked potential (MEP) in both affected and unaffected hemispheres compared to non- neuropathic pain and no-pain patients. Patients with CNP had lower amplitudes of MEPs (366 μV ±464 μV) than non-neuropathic (478 ±489) and no-pain (765 μV ± 880 μV) patients, p < 0.001. Short-interval intracortical inhibition (SICI) was defective (less inhibited) in patients with CNP (2.6±11.6) compared to no-pain (0.8±0.7), p = 0.021. MEPs negatively correlated with mechanical and cold-induced allodynia. Furthermore, classifying patients' results according to normative data revealed that at least 75% of patients had abnormalities in some CE parameters and confirmed MEP findings based on group analyses. DISCUSSION: CNP is associated with decreased MEPs and SICI compared to non-neuropathic pain and no-pain patients. Corticomotor excitability changes may be helpful as neurophysiological markers of the development and persistence of pain after CNS injury, as they are likely to provide insights into global CE plasticity changes occurring after CNS lesions associated with CNP.


CE changes, CE measurements, CE parameters, CNS injury, CNS lesions, MEP, MEP findings, abnormalities, allodynia, amplitude, analysis, assessment, batteries, brain injury, central neuropathic pain, changes, chronic pain, comprehensive pain, cord injury, corticomotor excitability, corticomotor excitability changes, data, development, disease, excitability, excitability changes, findings, group, group analysis, group of patients, hemisphere, inhibition, injury, insights, intracortical inhibition, lesion location, lesions, life assessment, location, low amplitude, lower motor, markers, measurements, mechanism, motor, neuromyelitis optica, neuropathic pain, neurophysiological markers, non-neuropathic pain, normative data, objective, optica, pain, pain patients, pain-free patients, parameters, patient results, patients, persistence, persistence of pain, plasticity changes, potential, quality, results, same disease, sex, short-interval intracortical inhibition, spinal cord injury, stroke, stroke patients, study, unaffected hemisphere


  • Danish National Research Foundation
  • Novo Nordisk (Denmark)
  • National Council for Scientific and Technological Development