A surgically implanted device that sends low levels of electricity directly into the spinal cord to relieve pain, is known as spinal cord stimulator. Spinal cord stimulators consist of two parts, the electrodes which are thin wires, and a pacemaker-like battery pack which is the generator. The electrodes are assigned between the spinal cord and vertebrae under x-ray or ultrasound, and the generator is placed under the skin around the buttocks or abdominal region. When turned on, the electrodes carry electrical current from the battery generator to the nerve fibers of the spinal cord. The aim of implanting the spinal cord stimulator is to replace the sensation signals of pain with a light tingling sensation before they reach the brain. This mild tingling feeling is known as paresthesia. The stimulator does not eliminate the pain but changes the way the brain perceives it. Patients can use a remote control (placed outside the body) to send electrical impulses through the wires into the spinal cord when they feel pain.

The three main types of spinal cord stimulators are:

• Conventional implantable pulse generator (IPG)– Battery operated spinal cord stimulator. Battery is placed in the spine during operation. Battery should be replaced with another surgery when it runs out. Recommended for people with pain in just one body part since it has a lower electrical output.
• Rechargeable IPG– functions like the conventional device. However, the battery can be recharged without the need of another surgery. Recharging the battery allows the wire stimulators to release more electricity. This device is a better choice for patients who experience pain in the lower back or in one or both legs.
• Radiofrequency stimulator– battery placed outside the body. This stimulator also has rechargeable batteries like the rechargeable IPG. However, it is rarely used today because of newer technology and designs.