Spinal Cord Stimulation for the Control of Chronic Back Pain
The use of electrical stimulation to relieve pain began in ancient times with the placement of torpedo fish directly onto painful body parts. Since then, the application of electrical stimulation to the body for pain relief has become much better and more sophisticated. In 1989, spinal cord stimulation (SCS) was approved by the Food and Drug Administration (FDA) as a treatment for chronic pain. Since that time, SCS has become a standard of care for patients with neuropathic chronic back and limb pain (nerve injury with abnormal nerve function producing pain). New technology has allowed for the development of neurostimulators that can allow patients with chronic back pain to reduce or eliminate their need for pain medications and return to comfortable, productive lives.
How Does Spinal Cord Stimulation Work?
In spinal cord stimulation, a tiny programmable generator and electrical leads are implanted beneath the skin. Small electrical currents are applied to the areas of the spinal cord involved in pain. For reasons that are not completely understood, these electrical impulses interfere with the transmission of pain signals to the brain and relieve pain without causing the side effects that medications can cause.
A pleasant tingling sensation is substituted for the pain and blocks the brain's ability to sense pain in the stimulated areas. This is similar to the relief felt by rubbing an area after getting an injury. The electrical impulses can be targeted to specific locations and, as pain changes or improves, stimulation can be adjusted as necessary.
What Is the Goal of Spinal Cord Stimulation?
The goal of SCS is to achieve significant or total relief from back pain and to be able to return to a happy, productive lifestyle. While this therapy does not work for everyone, most patients with SCS are able to report a 50% to 70% reduction in their overall pain and are able to decrease or completely taper off narcotic painkiller medications. With successful SCS, patients can function during normal activities, return to work, and fully participate in family and community life.
How Is Spinal Cord Stimulation Performed?
In spinal cord stimulation, the physician first numbs the skin using a local anesthetic. Soft, thin wires with electrical leads at the tip are placed through a needle (without any incision) into the back near the spinal column. The physician, either an interventional pain specialist or spine surgeon, determines the best location based on the individual patient's pain. The leads are then connected to a special programming device that can be used to program the electrical current in a pattern to exactly target the painful areas for the best relief possible.
What Is the SCS Trial? Why Not Implant the Permanent System Immediately?
To make sure the patient will benefit from SCS, a temporary system is implanted and tried for a few days or a week. For the SCS trial, leads are placed beneath the skin and attached to a small generator the patient carries. The generator is similar to a pager or cell phone. If the SCS trial is successful, a complete permanent system with a generator is implanted at another time. The leads for the permanent system can be inserted the same way as in the trial. A small generator is surgically implanted beneath the skin in the upper buttock or abdomen. The wires are then connected, and the entire system is implanted beneath the skin. Nothing is visible on the body.
Using a programming device outside the body, the system can be programmed in a way similar to using a remote control to adjust a television. The area or intensity of stimulation can be changed, and the system can be turned on and off or adjusted to provide the best pain relief. Programming is initially done at the physician's office, and patients can learn how to control the stimulation on their own at home to adjust it to their pain.
Many systems today have rechargeable batteries that can easily be recharged at home. To recharge the batteries, place the recharging unit over the skin where the generator is implanted. Batteries may require recharging several times a month.
The latest technology provides coverage of different pain types (sensations) simultaneously (ie, burning, aching, stinging). It is referred to as multiple independent constant current technology (MICC). Using this technology, each electrode lying over the spinal cord can be controlled independently. Currently, this technology is available with an added feature; the patient can program the stimulator with user-friendly software.