Spinal Cord Stimulator
A spinal cord stimulator is an implanted device that sends low levels of electricity directly into the spinal cord to relieve pain.
- Spinal cord stimulation is used most often after nonsurgical pain treatment options have failed to provide sufficient relief.
- Spinal cord stimulators require two procedures to test and implant the device: the trial and the implantation.
- Spinal cord stimulation can improve overall quality of life and sleep, and reduce the need for pain medicines. It is typically used along with other pain management treatments.
What is a spinal cord stimulator and how does it work?
Spinal cord stimulators consist of thin wires (the electrodes) and a small, pacemaker-like battery pack (the generator). The electrodes are placed between the spinal cord and the vertebrae (the epidural space), and the generator is placed under the skin, usually near the buttocks or abdomen. Spinal cord stimulators allow patients to send the electrical impulses using a remote control when they feel pain. Both the remote control and its antenna are outside the body.
Experts still don’t fully understand the mechanisms behind spinal cord stimulation, but they now know that it may target multiple muscle groups directly from the spine and even alter how the brain senses pain.
Traditional spinal cord stimulators replace the sensation of pain with light tingling, called paresthesia. For patients who find these paresthesiae uncomfortable, newer devices offer “sub-perception” stimulation that cannot be felt.
Many of the latest devices are placed by physicians with highly specialized training in interventional pain management under X-ray and/or ultrasound guidance.
What is spinal cord stimulation used for?
Spinal cord stimulation is used most often after nonsurgical pain treatment options have failed to provide sufficient relief. Spinal cord stimulators may be used to treat or manage different types of chronic pain, including:
- Back pain, especially back pain that continues even after surgery (failed back surgery syndrome)
- 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 stimulation can improve overall quality of life and sleep, and reduce the need for pain medicines. It is typically used along with other pain management treatments, including medications, exercise, physical therapy and relaxation methods.
Who should get a spinal cord stimulator?
As with all treatments, your doctor will want to make sure spinal cord stimulation is right for you — and that it is likely to provide significant relief from your chronic pain. To make this recommendation, your pain specialist will likely order imaging tests and psychological screening. Some insurance companies require psychological screening to ensure disorders like depression or anxiety aren’t worsening your pain.
Each patient is different, but generally people who benefit the most from spinal cord stimulation are those who:
- Have not experienced sufficient pain relief with medications, less-invasive therapies or prior surgeries
- Do not have psychiatric disorders that would decrease the effectiveness of the procedure
Spinal Cord Stimulator Types
Spinal cord stimulators come in three main types:
- Conventional implantable pulse generator (IPG) is a battery-operated spinal code stimulator. A battery is placed in the spine during an operation. When it runs out, the battery must be replaced with another surgery. 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 similar 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 rarely used today because of newer designs and better technology. 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 may require different stimulator settings, such as one setting that works better for sitting and another for walking). To help you easily access the most used settings, most devices allow doctors to save two or three preset programs. Some newer devices feature several waveforms for electricity delivery, including high frequency, burst and high-density stimulation.
Spinal Cord Stimulator Surgery
Spinal cord stimulators require two procedures to test and implant the device: the trial and the implantation.
Spinal Cord Stimulator Trial
The first step is a trial period. Your surgeon will implant a temporary device for you to test out. Guided by a specific type of X-ray called fluoroscopy, your surgeon will carefully insert the electrodes in the epidural space of the spine. The location of your pain affects where these electrodes will be placed along the spine. 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. The generator/battery will be outside the body, typically on a belt you’ll wear around your waist.
For about a week, you will evaluate how well the device reduces your pain. The trial is considered a success if you experience a 50% or greater reduction in pain level.
If unsuccessful, the wires can easily be removed in the clinic without damage to the spinal cord or nerves. If successful, surgery is scheduled to permanently implant the device.
Spinal Cord Stimulator Implantation
During the permanent implantation procedure, the generator is placed underneath the skin and the trial electrodes are replaced with sterile electrodes. Unlike the trial electrodes, these will be anchored by sutures to minimize movement.
The implantation can take about 1-2 hours and is typically performed as an outpatient procedure.
After the local anesthesia has been administered, your surgeon will make one incision (typically along your lower abdomen or buttocks) to hold the generator and another incision (along your spine) to insert the permanent electrodes. The incisions are about the length of a driver’s license. As in the trial procedure, fluoroscopy is used to determine where the electrodes are placed.
Once the electrodes and generator are connected and running, your surgeon will close the incisions.
Your surgeon may provide sedation to keep you comfortable and ask for your feedback during placement of the electrodes.
Spinal Cord Stimulator Recovery
Most patients leave the same day as their procedure — once the anesthesia has worn off. For several days after surgery, your incisions may be painful. Try not to stretch, twist or reach, which could pull at the incisions. Dressings will be placed over the incision sites, which can be removed after about 3 days. In most cases, incisions heal within about 2-4 weeks after surgery.
Your doctor will discuss you recovery plan, but generally lighter activity is recommended for about 2 weeks after surgery.
Once your surgeon approves you for regular activity, you can return to work and drive again (with the stimulator turned off). This is typically 1-2 weeks after surgery.
Spinal Cord Stimulator Complications
Complications of spinal cord stimulator surgery are rare, but no procedure is without risk. A small percentage of patients may experience:
- Infection, which may occur in the first 2-8 weeks.
- Device migration (i.e., the electrodes move from their original location and the stimulator doesn’t block pain as effectively). This often requires a follow-up surgery to put the electrodes back in the proper spot.
- Device damage (e.g., a fall or intense physical activity breaks the stimulator).
- Dural puncture. The dura mater surrounds the spinal cord. Spinal cord stimulators are inserted in the epidural space, the area just outside the dura mater. If a needle or electrode goes too deep and pierces it, cerebrospinal fluid may leak out. These punctures can cause severe headaches.
- Spinal cord trauma. Although extremely rare, spinal cord stimulator insertion can cause nerve injury and paralysis.
Living with a Spinal Cord Stimulator
Generally, the pain relief provided by spinal cord stimulators allows patients to do much more than they could before surgery, but there are certain restrictions to be mindful of.
Can I have X-rays and CT scans with a spinal cord stimulator?
So long as your spinal cord stimulator is powered off, X-rays and CT scans are generally safe. Before undergoing any scan, always let your doctor, nurse or technician know you have a spinal cord stimulator.
Are spinal cord stimulators MRI compatible?
No, MRIs are not always safe for those with spinal cord stimulation devices. Some newer devices are compatible with certain MRI machine models and scan locations, but your doctor will need to evaluate the specifics of your stimulator first. If your device is not MRI compatible, MRIs can cause serious injury.
Communicate with your pain specialist beforehand so that he or she can weigh in on whether a procedure will interfere with or harm your stimulator model.
Will my spinal cord stimulator set off airport security?
Yes, airport security gates will detect your stimulator, but your physician will give you an identification card that may allow you to bypass the machine.
Some people find that airport security gates cause uncomfortable (but harmless) interference with their stimulators. If you cannot avoid passing through the security screener, turn off your device before stepping through.
Can I drive with a spinal cord stimulator?
No, you should power off your stimulator when you’re driving or operating heavy machinery, as sudden changes in stimulation levels could cause distraction.
Can I swim with a spinal cord stimulator?
Swimming is fine with a permanent, implanted generator, but you cannot get your temporary stimulator wet. You will need to avoid baths and showers during that short trial period.