In this procedure, one or two wires (leads) are placed into the epidural space to provide electrical stimulation of the spinal cord, acting to interfere with the transmission of pain. This technique is very effective in arm and leg pain caused by nerve injuries and can also be useful in some types of low back pain. It has also been used to treat pain from vascular insufficiency and chest pain. The stimulation can be adjusted by the patient, thereby adding an element of personal control over the treatment of pain.
The leads are surgically implanted. Prior to such surgery, a trial is performed. During this trial, the leads are placed through the skin without an incision and attached to an external power supply worn on the patient's belt. The patient may then go home and use the devise for several days to determine effectiveness. Permanent implant considered only if the trial decreases the patient pain over 50% and improves function.
The permanent implant may consist of thin leads or larger flat paddle leads. The latter requires a more extensive surgical procedure called a laminotomy but provides more efficient energy output, less chance of movement and more extensive coverage. The thin leads require less invasive surgery but have an increased tendency to change position. In addition, the generator or power supply can either be implanted or worn externally. The decision regarding the type of permanent implant to be used is made on an individual basis, based on the pattern of the patient's pain, the results of the trial stimulation, and the patient's preference.
Watch an instructional video on the trial:
Watch an instruction video on the implant: