Transcutaneous electrical nerve stimulation effects on pain-intensity and endogenous opioids levels among chronic low-back pain patients: A randomised controlled trial

Article type: Research Article

Authors: Ezema, Charles Ikechukwu^a | Onyeso, Ogochukwu Kelechi^{a; b; c; *} | Nna, Emmanuel Okechukwu^d | Awosoga, Oluwagbohunmi A.^b | Odole, Adesola Christiana^e | Kalu, Michael Ebe^{c; f} | Okoye, Goddy Chuba^a

Affiliations: [a] Department of Medical Rehabilitation, Faculty of Health Sciences and Technology, College of Medicine, University of Nigeria, Nsukka, Enugu, Nigeria | [b] Faculty of Health Sciences, University of Lethbridge, Lethbridge, Alberta, Canada | [c] Emerging Researchers and Professionals in Ageing-African Network, Nigeria | [d] Safety Molecular Pathology Laboratory, Ranger’s Avenue, Enugu, Nigeria | [e] Department of Physiotherapy, Faculty of Clinical Sciences, College of Medicine, University of Ibadan, Ibadan, Oyo, Nigeria | [f] School of Rehabilitation Science, McMaster University, Hamilton, Ontario, Canada

Correspondence: [*] Corresponding author: Ogochukwu Kelechi Onyeso, Department of Medical Rehabilitation, Faculty of Health Sciences and Technology, College of Medicine, University of Nigeria, Nsukka, Enugu, Nigeria. E-mail: kzetfrank@yahoo.com.

Abstract: BACKGROUND: Transcutaneous electrical nerve stimulation (TENS) is a promising non-pharmacological modality for the management of chronic low back pain (CLBP), but its efficacy and mode of action have not been clearly established. OBJECTIVE: To evaluate the responses of plasma beta-endorphin (βE), met-enkephalin (ME), and pain intensity (PI) among patients with CLBP exposed to TENS or sham-TENS. METHODS: This double-blind trial involved 62 participants (aged 53.29 ± 5.07 years) randomised into TENS group (frequency 100 Hz, burst-rate 2 Hz, burst-width 150 μs, intensity 40 mA, duration 30 min), and sham-TENS group. The PI and plasma concentrations of βE and ME were measured at baseline, immediately (0 hr), 1 hr, 24 hrs, and 48 hrs post-intervention. Data were analysed using general linear model repeated measures, ordinal regression, one-way analysis of variance, Kruskal-Wallis test, independent and paired samples t-tests, Mann-Whitney U test, Wilcoxon signed-rank test, and Kendall’s tau coefficient. RESULTS: There was a significant temporal difference in PI between groups, F (1, 58) = 18.83, p< 0.001; the TENS group had better pain relief. The relative analgesic effect of TENS started immediately after the intervention (median difference [M⁢D] =-3, p< 0.001), peaked at 1 hr (M⁢D=-4, p< 0.001), and worn out by 24 hrs (M⁢D=-1, p= 0.029). However, there was no significant difference in βE and ME between the groups from 0 hr to 24 hrs post interventions, and no significant correlation between the PI, and βE, or ME. CONCLUSION: TENS significantly reduced PI up to 24 hrs after treatment.

Keywords: Beta-endorphin, met-enkephalin, physiotherapy, spondylosis, TENS analgesic

DOI: 10.3233/BMR-210146

Journal: Journal of Back and Musculoskeletal Rehabilitation, vol. 35, no. 5, pp. 1053-1064, 2022