Spinal cord stimulation works to mask pain signals before they reach the brain. It can improve overall quality of life and sleep, and reduce the need for pain medicines. This treatment is typically used along with other pain management techniques, including medications, exercise, physical therapy, and relaxation methods.
What is a spinal cord stimulator and how does it work?
The device itself consists of thin wires or and a small, pacemaker-like battery pack called the generator. These wires or electrodes are placed between the spinal cord and the vertebrae with the generator being placed under the skin, usually near the glutes or abdomen. Spinal cord stimulators allow patients to send the electrical impulses when they feel pain through the use of a remote control and antenna both located outside of the body.
Traditional stimulators replace the sensation of pain with light tingling, called paresthesia. For patients who find this sensation uncomfortable, newer devices offer “sub-perception” stimulation that cannot be felt. These devices are placed under X-ray and/or ultrasound guidance by physicians with specialized training in interventional pain management.
Spinal cord stimulators require two procedures to test and implant the device. The first step is a trial period where a temporary device is implanted and left for the duration of one week to test if it is effective at reducing pain in the targeted area. Guided by a specific type of X-ray called fluoroscopy, your surgeon will carefully insert the electrodes in the epidural space of the spine as determined by the location of your pain. Your surgeon may ask for your feedback during the procedure to best position the electrodes. This trial procedure typically requires only one incision in your lower back to place the electrodes and the generator/battery will be outside the body, typically on a belt to be worn around your waist. The trial is considered a success if you experience a 50% or greater reduction in pain level. If successful, surgery is scheduled to permanently implant the device. If unsuccessful, the wires can easily be removed in the clinic without damaging the spinal cord or nerves.
During the permanent implantation procedure, the generator is placed underneath the skin and the trial electrodes are replaced with new, sterile electrodes. Unlike the trial electrodes, these will be secured by sutures to minimize movement. After the local anesthesia has been administered, your surgeon will make two incisions measuring about the length of a credit card to place the device. One incision (typically along your lower abdomen or buttocks) will be to hold the generator and another incision (along your spine) to insert the permanent electrodes. Similar to the trial procedure, fluoroscopy is used to determine where the electrodes are placed. Your surgeon may provide sedation to keep you comfortable and ask for your feedback during placement of the electrodes. Once the electrodes and generator are connected and running, your surgeon will close the incisions. Overall, the implantation can take roughly 1-2 hours and is typically performed as an outpatient procedure.
What is spinal cord stimulation used for?
Spinal cord stimulation is often used after nonsurgical pain treatment options have failed to provide sufficient relief as a way to treat or manage different types of chronic pain, including:
- Back pain, especially in cases where pain continues even after surgery
- Post-surgical pain
- Arachnoiditis (painful inflammation of the arachnoid, a thin membrane that covers the brain and spinal cord)
- Heart pain (angina) untreatable by other means
- Injuries to the spinal cord
- Nerve-related pain (such as severe diabetic neuropathy and cancer-related neuropathy from radiation, surgery or chemotherapy)
- Peripheral vascular disease
- Complex regional pain syndrome
- Pain after an amputation
- Visceral abdominal pain and perineal pain
Spinal cord stimulators types
These devices are available in three main types:
- Conventional implantable pulse generator (IPG) is a battery-operated spinal cord stimulator. A battery is placed in the spine during an operation and must be replaced with another surgery once it runs out. This device can be a good choice for people with pain in just one body part because it has a lower electrical output.
- Rechargeable IPG works similarly to the conventional device, with the difference that the battery can be recharged without another surgery. Because the energy source is rechargeable, these stimulators can put out more electricity. This may be a better choice for people with pain in the lower back or in one or both legs, as the electrical signal can reach further.
- Radiofrequency stimulator uses a battery that’s outside the body. This stimulator is hardly used today because of its newer, more advanced counterparts. It has rechargeable batteries, and like the rechargeable IPGs, it may be better for people with pain in the lower back and legs because of the device’s power.
Your surgeon will explain how to operate the device and adjust the intensity of the electrical signal, which all three types of stimulators support. Different body positions (such as walking and sitting) may require different stimulator settings. To help you easily access the most used settings, most devices allow doctors to program two or three customized preset settings.