Hadzic's Regional Anesthesia > Part II. Foundations of Regional Anesthesia > Section One. Anatomy & Electrophysiology > Chapter 5. Peripheral Nerve Stimulators & Electrophysiology of Nerve Stimulation Ban C. H. Tsui, MD, Admir Hadzic, MD

Peripheral Nerve Stimulators & Electrophysiology of Nerve Stimulation: Introduction

"Eliciting paresthesia or nerve stimulation are commonly used methods for localizing nerves prior to the injection of local anesthetic. Paresthesia is thought to result from mechanical stimulation of the nerve, resulting in a sensory feeling described as "an electric current" or "shock" in the sensory distribution of the nerve that is being touched. As such, paresthesia can indicate that the needle is in close proximity to the nerve and may be a warning sign of impending mechanical injury, should the needle be further advanced. In contrast, nerve stimulation techniques rely on the use of electric current to elicit motor stimulation of nerves and confirm the proximity of the needle to the nerve...."