Korean J Pain 2021; 34(4): 437-446
Published online October 1, 2021 https://doi.org/10.3344/kjp.2021.34.4.437
Copyright © The Korean Pain Society.
1Department of Rehabilitation Medicine, Gyeongsang National University Hospital, Jinju, Korea
2Department of Neurology, Gyeongsang National University Hospital, Jinju, Korea
3Department of Rehabilitation Medicine, Gyeongsang National University College of Medicine, Jinju, Korea
4Department of Neurology, Gyeongsang National University College of Medicine, Jinju, Korea
5Institute of Health Science, Gyeongsang National University College of Medicine, Jinju, Korea
Correspondence to:Oh-Young Kwon
Department of Neurology,Gyeongsang National University Hospital, Gyeongsang National University College of Medicine, 816-15 Jinjudae-ro, Jinju 52727, Korea
Chul Ho Yoon
Department of Rehabilitation Medicine, Gyeongsang National University Hospital, Gyeongsang National University College of Medicine, 816-15 Jinjudae-ro, Jinju 52727, Korea
Handling Editor: Won-Hyung Lee
Received: March 4, 2021; Revised: June 11, 2021; Accepted: June 16, 2021
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Background: Non-invasive painless signaling therapy (NPST) is an electro-cutaneous treatment that converts endogenous pain information into synthetic non-pain information. This study explored whether pain improvement by NPST in failed back surgery syndrome (FBSS) patients is related to cerebral modulation.
Methods: Electroencephalography (EEG) analysis was performed in 11 patients with FBSS. Subjects received daily NPST for 5 days. Before the first treatment, patients completed the Brief Pain Inventory (BPI) and Beck Depression Inventory and underwent baseline EEG. After the final treatment, they responded again to the BPI, reported the percent pain improvement (PPI), and then underwent post-treatment EEG. If the PPI grade was zero, they were assigned to the ineffective group, while all others were assigned to the effective group. We used standardized low-resolution brain electromagnetic tomography (sLORETA) to explore the EEG current-source distribution (CSD) associated with pain improvement by NPST.
Results: The 11 participants had a median age of 67.0 years, and 63.6% were female. The sLORETA images revealed a beta-2 CSD increment in 12 voxels of the right anterior cingulate gyrus (ACG) and the right medial frontal area. The point of maximal CSD changes was in the right ACG. The alpha band CSD increased in 2 voxels of the left transverse gyrus.
Conclusions: Pain improvement by NPST in FBSS patients was associated with increased cerebral activity, mainly in the right ACG. The change in afferent information induced by NPST seems to be associated with cerebral pain perception.
Keywords: Chronic Pain, Electric Stimulation Therapy, Electroencephalography, Failed Back Surgery Syndrome, Gyrus Cinguli, Information Theory, Neuroimaging, Neuronal Plasticity, Pain Perception.