The effect of high tone external muscle stimulation on polyneuropathy: a systematic review and meta-analysis

Abstract

Background and study aim. High-tone therapy, also known as High-Frequency External Muscle Stimulation (HTEMS), is a more recent and unique form of electrotherapy treatment. Unlike traditional electrotherapy methods, which use a single frequency, high-tone therapy modulates both frequency and amplitude to deliver more energy to the tissues. The options for treating neuropathy associated with any illness, including diabetes, are limited, especially non-pharmacological therapies. This review aims to investigate the evidence of the effectiveness of high-tone external muscle stimulation (HTEMS) for patients with polyneuropathy. Material and Methods. Google Scholar, Scopus, web of Science, PubMed, EMBASE, the Cochrane Central Register of Control Trials, CENTRAL, and Physiotherapy Evidence Database, Pedro, databases from inception to February 2022. We restricted the search to articles published in English only. Randomized controlled trials, RCTs, of HTEMS for peripheral neuropathy were included. Two independent reviewers screened the articles for eligibility, extracted the data, and assessed the risk of bias in eligible studies. Meta-analysis was performed using the random-effects model. The remaining results were presented using descriptive methods. The risk of bias was assessed using the PEDro scale. Results. Six articles fulfilled the eligibility criteria with 487 participants. Most trials have focused on investigating the effectiveness of HTEMS in treating diabetic polyneuropathy and entrapment neuropathies. Overall, HTEMS provided a slight, but not clinically significant, reduction in pain and Katz index scores compared with mean control difference with p is more then 0.05. Conclusions. HTEMS has been proven to be more efficient in most aspects, such as reduction in pain intensity and Katz index scores in patients with polyneuropathy compared to other treatment options. The included trials presented methodological issues and high heterogeneity, preventing the establishment of any firm recommendations to support or refute the use of HTEMS as a strategy for managing neuropathic pain.