Nerve stimulation comes in many shapes and forms. There are Central and Peripheral nerves in the body that send impulses and can be treated to modify how the brain and you body react.
Central Stimulation works in the Brain and Spinal Cord. Inserting these types of stimulators require the use of surgical and minimally invasive procedures. They have a higher risk of complications and are difficult to remove when they aren't as effective. Spinal cord stimulators have many different types and programming; sometimes can move positions after placements. They are very effective and very expensive. Most Insurance plans do cover this procedure. There is an intitial trial period prior to a permanent placement. The battery is generally also implanted under the skin.
Peripheral Nerve Stimulation is placed over the Nerves most closely related to where the problems are being felt or coming from. These can be done in a minimially invasive and quick surgicenter setting. Some Stimulators can be temporarily placed, or used to determine the need for a permanent placement. The SPR brand is meant to do this and is a 60 day average treatment. Other manufacturers have longer acting products as well. The batteries for these tools are generally on the outside of the body and easy to charge, change and protect from the environment.