What is a Spinal Cord Stimulator Implant?

Spinal cord stimulation (known as SCS or neuromodulation) is a treatment modality used for chronic pain. The implantable stimulator emits mild electric current to block nerve impulses in the spine. Many chronic conditions are treated using a spinal cord stimulator implant.

How big is a spinal cord stimulator device?

The generator is a small implantable device that administers small electrical current to the nerves that transmit pain signals. Depending on the SCS system, the generator unit is around 2 inch x 2 inch. Inside the stimulator is a tiny battery. The leads are only a few millimeters, and they have wires that attach to the generator.

How does the spinal cord stimulator implant work?

The neuromodulation system works based on the principles of neurostimulation. The generator sends mild electrical currents to the nerves. These currents prevent the brain from perceiving chronic pain signals. This allows for great pain reduction for the patient.

What conditions are treated using a spinal cord stimulator implant?

Spinal cord stimulators are used to treat many upper and lower body pain disorders, as well as back conditions. Some of the reasons for using a SCS system include:

• Failed back surgery syndrome (FBSS) – Also called postlaminectomy syndrome, this condition is characterized by symptoms that occur or continue following spinal surgery.

• Diabetic and peripheral neuropathy – This is nerve damage caused by high levels of glucose or injury to the peripheral nerves. Symptoms include persistent leg pain, numbness, and tingling.

• Complex regional pain syndrome (CRPS) – Patients with this condition suffer from chronic pain following a traumatic injury to a leg or arm.

• Chronic neck pain – Some patients suffer chronic pain of the cervical spine related to past injury, degenerative disc disease, spinal stenosis, and herniated disc.

• Peripheral vascular disease (PVD) – Patients with this condition have persistent and chronic leg pain that can be debilitating.

How is a neuromodulation implant performed?

The spinal cord stimulator implant procedure is usually done in a two-step process. First, the patient undergoes a 5-7 day trial period of a temporary stimulator to see if the device is effective. This involves implanting only leads along the spinal column which attach to a device worn outside the body. The trial must relieve pain by 50% to be effective.

If the trial proves the SCS device effective, the patient will undergo surgery for permanent placement of the spinal cord stimulator implant. This procedure is performed under general anesthesia. An incision is made over the skin of the spine, with location depending on the condition. Using real-time x-ray and a hollow needle, the leads are placed along the epidural space.

Another incision is made in the lower abdomen or buttock so the stimulator can be implanted. The device is placed on top of muscle and below the skin. Wires are threaded from the stimulator to the leads. The incisions are closed using sutures, and a dry bandage is applied.

How effective are spinal cord stimulator implants?

According to studies, the spinal cord stimulator implant has a 70-90% efficacy rate. Patients report that they are able to resume some of their normal activities, and pain medication usage is reduced.

What complications and risks are associated with the spinal cord stimulator?

As with any type of surgery, some basic, common risks must be considered. While rare, these include:

• Leakage of cerebrospinal fluid
• Nerve damage, which can cause weakness, paralysis, and/or pain
• Infection
• Post-surgical pain
• Post-surgical movement or damage to the leads or generator
• Difficulty in programming the implant

Resources

Kumar K, Nath R, & Toth C (1997). Spinal cord stimulation is effective in the management of reflex sympathetic dystrophy. Neurosurgery 40: 503-509.

Kumar A, Pandey AK, & Okun MS (2012). Clinical neurophysiology. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC, eds. Bradley’s Neurology in Clinical Practice. 6th ed. Philadelphia, PA: Elsevier Saunders. Chap 32D.

Reig E & Abejón D (2009). Spinal cord stimulation: a 20-year retrospective analysis in 260 patients. Neuromodulation, 12(3):232–239.