An algorithm for the use of various transcutaneous electrical nerve stimulation modalities in treatment of patients with residual positive sensory symptoms after surgical decompression of the carpal tunnel

BACKGROUND: The main cause of residual neurological symptoms after surgical carpal tunnel decompression is long-term compressive neuropathy of the median nerve in the carpal tunnel in the preoperative period. As a result, irreversible morphological and neurophysiological changes gradually develop on the part of the compressed median nerve, which may not recover after its decompression.

AIM: To establish an algorithm for the use of transcutaneous electrical nerve stimulation (TENS) of various modalities in the treatment of patients with residual neurological symptoms after undergoing surgical carpal tunnel decompression.

MATERIALS AND METHODS: We observed 100 patients with residual positive symptoms after undergoing successful of surgical decompression of the carpal tunnel. The control group consisted of 20 patients (10 women and 10 men) and underwent a 2-month course of standard drug therapy. The main group (n=80), in addition to the standard drug therapy carried out in the control group, underwent a course of TENS, which began on the 2nd month of drug treatment. Depending on the form of TENS therapy, patients of the main group were divided into 4 subgroups: the TENS placebo subgroup (n=20) underwent a course of ineffective TENS. High-frequency TENS subgroup (n=20) completed a course of high-frequency low-amplitude TENS. Low-frequency TENS subgroup (n=20) completed a course of low-frequency high-amplitude TENS. The high-frequency TENS + low-frequency TENS subgroup underwent a simultaneous course of high-frequency TENS and low-frequency TENS (n=20). Positive sensory symptoms of numbness, tingling, burning and a feeling of electric charge were rated by the patients themselves over the past 24 hours on a 10-point scale.

RESULTS: When comparing the subgroups of effective TENS (high-frequency TENS, low-frequency TENS, high-frequency TENS + low-frequency TENS) with the subgroup of ineffective TENS (placebo), a significant decrease in positive sensory symptoms was revealed in the subgroups of high-frequency TENS, low-frequency TENS, high-frequency TENS and low-frequency TENS by 112%, 40% and 163% respectively. When comparing the effectiveness of high-frequency TENS and low-frequency TENS with each other, it was possible to establish that high-frequency TENS exceeds the efficiency of low-frequency TENS by almost 2 times. However, the combination of low-frequency TENS with high-frequency TENS enhances the therapeutic effect of the latter by 46%.

CONCLUSION: The use of high-frequency TENS is recommended in the treatment of patients with residual positive sensory symptoms. For strong positive sensory symptoms with the development of secondary affective reactions, it is recommended to combine high-frequency TENS and low-frequency TENS to enhance the effect.