A spinal cord stimulator, also called a dorsal column stimulator is a device which stimulates pain-carrying nerves via small electrical wires placed in the “epidural space” just outside the spinal cord.
Spinal cord stimulation is offered to patients with chronic and severe neuropathic (pain from damaged nerve tissue) pain. Some patients may have neuropathic pain in their extremities and some may have severe chronic low-back pain after spine surgery. It is for patients who have not responded to other treatment modalities. Sometimes it is offered to patients that due to health or age reasons cannot undergo spine surgery.
A spinal cord stimulator interrupts nerve conduction along certain types of nerves that predominantly carry pain signals to the brain.
This is a two-stage procedure. The first stage is the trial stage and does not involve any surgery. Through a specialized needle, one or two wires are placed in the epidural space. These wires are attached to an external generator which the patient controls. The wires may be left in place for up to 5-7 days. During this phase, the patient engages in relatively normal activity and gauges the effectiveness of the device. If it is successful and the patient is satisfied by the degree of pain relief, the second stage involves placing the wires under the skin, tunneling the wires to the location of the battery, and placement of the battery just under the skin. Each procedure can take up to 1-2 hours.
All of our procedures begin by injecting a small amount of local anesthetic through a very small needle. It feels like a little pinch and then a slight burning as the local anesthetic starts numbing the skin. After the skin is numb, the procedure needle feels like a bit of pressure at the injection site.
The placement of the wires is done under local anesthesia with patients mildly sedated. This is necessary to ensure proper placement of the wires. The amount of sedation given generally depends upon the patient tolerance. For the generator placement, patients are given stronger intravenous sedation. Patients may not have much memory of the procedure though they will communicate with us.
It is done with the patient lying on the stomach when placing the wires. For the insertion of the generator, patients are placed on their back or on the side. The patients are monitored with EKG, blood pressure cuff and blood oxygen-monitoring device. The skin is cleaned with antiseptic solution and then the procedure is carried out. X-ray (fluoroscopy) is used to guide the needle for wire placement.
For the pain involving lower back and lower extremities, the wires are inserted in the midline at the lower back. The generator is then placed on the side of the abdomen. For the pain involving upper extremities, the wires are inserted in the midline at the upper back. The generator is then placed on the side of the chest.
If the procedure is successful, you may feel that your pain may be gone or quite less. You will experience a fairly constant sensation of stimulation. You may have soreness due to the needles used for a day or two. Generally, the procedure gives a reduction in the amount of pain and may decrease the amount of medications needed.
This procedure is normally a day-procedure. Some patients may be kept overnight for observation. You should have a ride home. We advise patients to take it easy for a day or so after the procedure. Perform the activities as tolerated by you.
The implanted generators are rechargeable and the charging interval depends on the amount of power required by you to feel comfortable. Recharge intervals are typically every 2-4 weeks. The generator has a 5-year guarantee but is expected to last much longer.
Generally speaking, this procedure is safe. However, with any procedure there are risks, side effects, and possibility of complications. Please discuss your concerns with your physician.
The following patients should not have this injection: if you are allergic to any of the medications to be injected, if you are on a blood-thinning medication (e.g. Coumadin, injectable Heparin), or if you have an active infection going on. With blood thinners like Coumadin, your doctor may advise you to stop this for 4-7 days beforehand or take “bridge therapy” with Lovenox prior to the procedures. Anti-platelet drugs like Plavix may have to be stopped for 5-10 days prior to the procedure.