Can you tell me more about pain pumps and spine stimulator's?

These are ways of: Treating severe chronic pain when all else had failed with pumps being used primarily in cancer treatment ; spastic conditions through the administration of drugs directly to spinal region with spinal cord stimulators used primarily for pain in limbs after failed back surgery, peripheral neuropathy, phantom limb pain, rsd or crps, certain bladder conditions -both treatments require a trial first.