The combined effect of neuro-modulation and neuro-stimulation on pain in patients with cervical radiculopathy – a double-blinded, two-arm parallel randomized controlled trial

Abstract

Introduction Cervical radiculopathy is one of those disabling conditions which results in central and peripheral pain and thus affects the quality of life. Transcutaneous Electrical Nerve Stimulation (TENS) and exercises produce analgesic effect but their long-term effect has not been available to date. Transcranial Direct Current stimulation (tDCS) is known to produce promising effects on central pain by targeting cortical activity. Purpose To determine the combined effect of tDCS and TENS with exercises on pain and quality of life in patients with cervical radiculopathy. Method Forty four patients (male: female = 26:18) of the age group 18–50 years were recruited and randomly allocated into the experimental group and control group. The experimental group received active anodal tDCS for 20 min with an intensity of 2 mA, while the control group received sham anodal tDCS. TENS over the pain distribution area for 20 min with 5 Hz intensity and 80-150 ms pulse duration followed by neck-specific exercises were given in both groups. This protocol was given 5 days a week for 4 weeks. Pre and post-assessments were obtained through outcome measures that the Numeric Pain Rating Scale and Neck Disability Index for the measurement of pain, functional disability, and quality of life. Result Paired t-test/Wilcoxon-Signed Rank test, and Index and Mann–Whitney U test were used to compare the demographic variables within and across the groups, respectively for Neck Disability for Numeric Pain Rating Scale, keeping the P-value < 0.05 as significant. One-way repeated-measures analysis of variance (ANOVA) was applied to determine the between-subject factor differences. Post hoc tests with Bonferroni correction for repeated analyses were performed. Results depicted a significant effect for NDI (P = 0.001 for both groups) and NPRS (P = 0.003 for the experimental group and 0.007 for the control group). Significant Interaction effect (time*group) was observed for NDI (F = 42, 5382.77) and NPRS (F = 42, 1844.57) with a P-value of 0.001 for both outcome measures. Clinical significance was observed for both outcome measures having a mean difference in 50.21 and 4.57 for NDI and NPRS, respectively compared with the established MCID of 13.2 and 2.2 scores for respective outcome measures. Conclusion It was concluded that active tDCS along with TENS and exercise intervention was effective on pain, disability, and quality of life in patients with cervical radiculopathy.