Peripheral Nerve Stimulation

Peripheral nerve stimulation (PNS) is a safe, adjustable, and reversible treatment option for patients with medically refractory neuropathic pain localized to the distribution of a peripheral nerve. Since its initial introduction in the 1960s following the development of the gate control theory, PNS has been used to treat chronic neuropathic pain in the craniofacial area, the trunk, and the extremities. It is based on the discovery that stimulation of a peripheral nerve activates large-diameter fibers preferentially over smaller diameter pain fibers, resulting in the mitigation of centrally perceived pain. In the decades since its initial clinical application, the electrodes and stimulation parameters employed have continued to evolve. More recently, paresthesia-free stimulation has been described through novel stimulation paradigms including burst and high-frequency stimulation. Currently, in most cases, spinal cord stimulator systems are adapted for peripheral nerve stimulation with the use of multi-contact percutaneous leads placed in proximity to the targeted nerve, although novel purpose-specific PNS systems have begun to emerge. Recently, transcutaneous powered systems specifically designed for PNS have become available. In this chapter, we primarily discuss the physiology of peripheral sensory nerves, theories of pain perception, biophysics of PNS, and clinical applications. In addition, we briefly discuss how peripheral nerve stimulation can modulate central nervous system pathology, with attention given to the treatment of epilepsy and depression.