Kilohertz Electrical Stimulation Nerve Conduction Block: Effects of Electrode Material

Kilohertz electrical stimulation (KES) has enabled a novel new paradigm for spinal cord and peripheral nerve stimulation to treat a variety of neurological diseases. KES can excite or inhibit nerve activity and is used in many clinical devices today. However, the impact of different electrode materials on the efficacy of KES is unknown. We investigated the effect of different electrode materials and their respective charge injection mechanisms on KES nerve block thresholds using 20- and 40-kHz current-controlled sinusoidal KES waveforms. We evaluated the nerve block threshold and the power requirements for achieving an effective KES nerve block. In addition, we evaluated potential effects on the onset duration and recovery of normal conduction after delivery of KES. We found that thresholds and the onset and recovery of KES nerve block are not a function of the electrode material. In contrast, the power dissipation varies among electrode materials and is a function of the materials' properties at high frequencies. We conclude that materials with a proven track record of chronic stability, both for the tissue and electrode, are suitable for developing KES nerve block therapies.