Pudendal Nerve Block by Low-Frequency (≤1 kHz) Biphasic Electrical Stimulation

Area of Science:

• Neuroscience
• Biomedical Engineering

Background:

• Nerve conduction block is crucial for neuromodulation.
• High-frequency biphasic stimulation (HFBS) is known to induce poststimulation block.
• The efficacy of low-frequency biphasic stimulation (LFBS) for nerve block is less understood.

Purpose of the Study:

• To investigate if LFBS (≤1 kHz) can induce a reversible poststimulation block of nerve conduction.
• To compare the effectiveness of different LFBS frequencies (100 Hz, 500 Hz, 1 kHz).

Main Methods:

• A tripolar cuff electrode delivered LFBS to the pudendal nerve in cats.
• External urethral sphincter (EUS) contractions and pressure were recorded.
• Nerve block was confirmed by assessing the ability to induce EUS contractions via stimulation at different points relative to the cuff.

Main Results:

• LFBS at 100 Hz, 500 Hz, and 1 kHz completely blocked pudendal nerve conduction.
• The block was reversible, with recovery in 10-15 minutes.
• Stimulation duration required for block increased with frequency, from 23±8 sec at 100 Hz to 95±14 sec at 1 kHz (p<0.05).

Conclusions:

• LFBS (≤1 kHz) can induce a reversible poststimulation nerve conduction block, analogous to HFBS.
• Results support the ion concentration theory for biphasic stimulation-induced block.
• This finding enables the development of new neuromodulation devices for clinical use.