 A small pocket is cut into the tissue beneath the skin of the upper buttocks, chest wall or abdomen and the leads are threaded under the skin from the stimulation site to the pocket, where they are attached to the snugly-fitting generator.It seems to be more helpful with neuropathic and ischemic pain than nociceptive pain, and is not often used in the treatment of cancer pain.Ongoing electrical stimulation of structures deep within the brain – the periaqueductal gray and periventricular gray for nociceptive pain, and the internal capsule, ventral posterolateral nucleus and ventral posteromedial nucleus for neuropathic pain – has produced impressive results with some patients but results vary and appropriate patient selection is important.