Peripheral or Electrical Nerve Stimulation involves sending mild electrical nerve stimulation to treat chronic pain. Peripheral Nerve Stimulation and Spinal Cord Stimulation are two types of Electrical Nerve Stimulation (ENS). Small pulse generator sends electrical pulses either to the nerves or the spine. These pulses help intercept the nerve impulses that send pain signals. This treatment is most often administered to treat complex regional pain syndrome. Your physician will first insert a small electrode into the skin to see whether that helps ease the pain. The electrode is connected to a simulator that the patient can control.