Effect of Low FrequencyTranscutaneous Magnetic Stimulation on Sensory and Motor Transmission - Case Study

INTRODUCTION

After a peripheral nerve injury, fast conducting large myelinated afferent A-bcta fiber transmission diminishes over time. On the other hand, firing of smaller pain transmitting fibers such as A-dclta and C-fibcrs is enhanced. This aberrant afferent neuronal behavior is thought to be one of the main neuronal mechanisms leading to development of chronic posttraumatic peripheral neuropathic pain (PTP-NP) [Puig and Sorkin, 1996). Clinically, this persistent peripheral neuropathic pain state is often refractory to invasive interventions or medication [Sorkin and Yaksh, 2009; Rajput et al., 2012]. Non-invasive ncuromodulation offers an appealing alternate therapeutic option in treating this often debilitating chronic pain condition. While it is known that transcutaneous electrical nerve stimulation (TENS) may slow afferent nerve conduction, particularly in large afferent fibers, and provide temporary pain relief [Walsh ct al., 1995b; Koga et al., 2005], its application in managing patients with PTP-NP has been limited due to either on-site or surrounding tissue pain sensitivity to TENS electrodes and actual electrical stimulation. Recently, technology involving dynamic magnetic flux, derived from basic electromagnetic coupling principles [Lisanby ct al., 2000], has been applied both centrally