Abstract
Transcutaneous electrical nerve stimulation (TENS) is a non-invasive therapeutic intervention that is typically used for many years to treat chronic pain in patients who are refractory to pain medications. However, evidence of the efficacy of TENS treatment for neuropathic pain is lacking in humans. To further understand the efficacy of TENS under various intervention conditions and illuminate the current circumstance and future research directions, we systematically reviewed animal studies investigating the efficacy of TENS in relieving pain in neuropathic pain rodent models. We searched the Cochrane Library, EMBASE, MEDLINE (via PubMed), and Web of Science and identified 11 studies. Two meta-analyses were performed. The first meta-analysis showed that a single TENS treatment was capable of temporarily ameliorating neuropathic pain when compared to control groups with a significant effect (standardized mean difference: 1.54; 95% CI: 0.65, 2.42; p = 0.0007; I2 = 58%). Significant temporary alleviation in neuropathic pain intensity was also observed in the meta-analysis of repetitive TENS (standardized mean difference: 0.85; 95% CI: 0.31, 1.40; p = 0.002; I2 = 75%). Subgroup analysis showed no effect of the timing of the application of TENS (test for subgroup difference, p = 0.47). Leave-one-out sensitivity analyses suggested that no single study had an outsized effect on the pooled estimates, which may partly prove the robustness of these findings. Other stratified analyses were prevented by the insufficient number of included studies. Overall, current data suggest that TENS might be a promising therapy to ameliorate neuropathic pain. However, the high risk of bias in the included studies suggests that cautions must be considered when interpreting these findings and it is not reasonable to directly generalize the results obtained from animal studies to clinical practice. Future studies should pay more attention to improving the quality of study design and reporting, thereby facilitating the understanding of mechanisms underlying TENS treatment, reducing more potentially unsuccessful clinical trials, and optimizing the efficacy of TENS for people with neuropathic pain.
Highlights
Neuropathic pain, which is caused by an injury or disease of the somatosensory system, is characterized by spontaneous pain, hyperalgesia, and allodynia and can be classified as peripheral or central neuropathic pain according to the site of injury or disease (Treede et al, 2008)
Forty-three records were remained to determine their eligibility by carefully fulltext screening, followed by 32 records were excluded from this review for various reasons
Repetitive Transcutaneous electrical nerve stimulation (TENS) groups significantly ameliorated neuropathic pain relative to comparators (SMD: 0.85; 95% CI: 0.31, 1.40; p = 0.002; I2 = 75%; Figure 3)
Summary
Neuropathic pain, which is caused by an injury or disease of the somatosensory system, is characterized by spontaneous pain, hyperalgesia, and allodynia and can be classified as peripheral or central neuropathic pain according to the site of injury or disease (Treede et al, 2008). A Cochrane Review of TENS for neuropathic pain reported that they cannot confidently state whether TENS is efficacy for neuropathic control due to the low-quality evidence obtained from a small number of studies included in the meta-analysis, and the lack of clinical studies prevented further subgroup analyses, resulting in the optimal pattern of TENS remaining unknown (Gibson et al, 2017). Previous animal studies have explored the effect of TENS on neuropathic pain, but results have not been consistent (Somers and Clemente, 2009; Lin et al, 2015; Su et al, 2018). No meta-analysis has assessed the antinociceptive effect of TENS in alleviating neuropathic pain
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
