Cortical and subcortical SEPs following posterior tibial nerve stimulation

Mechanism of Action of Tibial Nerve Stimulation in the Treatment of Lower Urinary Tract Dysfunction

BACKGROUND AND OBJECTIVE

Tibial nerve stimulation (TNS) has long been used to effectively treat lower urinary tract dysfunction (LUTD). Although numerous studies have concentrated on TNS, its mechanism of action remains elusive. This review aimed to concentrate on the mechanism of action of TNS against LUTD.

MATERIALS AND METHODS

A literature search was performed in PubMed on October 31, 2022. In this study, we introduced the application of TNS for LUTD, summarized different methods used in exploring the mechanism of TNS, and discussed the next direction to investigate the mechanism of TNS.

RESULTS AND CONCLUSIONS

In this review, 97 studies, including clinical studies, animal experiments, and reviews, were used. TNS is an effective treatment for LUTD. The study of its mechanisms primarily concentrated on the central nervous system, tibial nerve pathway, receptors, and TNS frequency. More advanced equipment will be used in human experiments to investigate the central mechanism, and diverse animal experiments will be performed to explore the peripheral mechanism and parameters of TNS in the future.

P37 latency mismatch between lateral and midline potentials is influenced by transversal afference

SUMMARY

P37 cortical peak latency registered on Ci' (lateral) is usually approximately 1 millisecond shorter than Cz' (midline) in lower limb somatosensory evoked potential. At the present time, the underlying mechanism that leads to this mismatch remains unknown. Superficial peroneal nerve, posttibial nerve, and sural nerve somatosensory evoked potentials were obtained from 26 anesthetized individuals by using Ci'-Cc', Cc'-Fpz, and Cz'-Fpz recording montages. P37 latency mismatches between the lateral (Ci'-Cc') and midline (Cz'-Fpz) potentials (P < 0.001) were recorded in superficial peroneal nerve, posttibial nerve, and sural nerve somatosensory evoked potentials; all showed shorter Ci'-Cc' P37 latency (1-1.7 milliseconds). However, in individuals who had minimal or no N37 potential on Cc' recording, the mean P37 latencies of Ci'-Cc' and Cz'-Fpz equalized with the P37 latency of Ci'-Cc' approaching to default Cz'-Fpz value. The data showed that N37 seemed to potentiate the P37 latency difference between Ci-Cc' and Cz'-Fpz recordings. We postulate that N37 may preferentially reflect the dipoles of transversal afference; lack of it thereof suggests poor dipole sources primarily perpendicular to the mesial hemisphere.