ID: 216418 Activation of Inhibitory Circuit in Reflex Motor Pathways by 10kHz Versus Single Pulse/Low Frequency SCS

Abstract

High frequency (10kHz) spinal cord stimulation (SCS) is a well-established and expanding neuromodulatory technique for treating chronic pain. Despite clinical success, the cellular mechanisms of 10kHz SCS for activating neurons is still not fully understood. In previous preclinical work, we reported that 10kHz SCS activated the thigh muscle selectively, with very little activation by single pulse (low frequency) SCS. The toe muscle showed a similar but opposite selectivity, where single pulse/low frequency SCS resulted in more selective activation of the toe than 10kHzSCS. In the literature, both animal and human studies reported that use of a paired pulse protocol generates recurrent, presynaptic inhibition and homosynaptic depression depending on the delay between first and second pulses. Here we studied the activation of inhibitory circuits in reflex motor pathways using a paired pulse protocol of 10 kHz SCS vs. low frequency/single pulse SCS.