Dorsal Column Stimulation for Chronic Back Pain
What is dorsal column stimulation?
Dorsal column stimulation (DCS), also known as spinal cord stimulation (SCS), is a minimally invasive, reversible treatment that uses electricity to interfere with the transmission of pain signals to the brain. The procedure has been approved by the FDA to treat various chronic and back pain conditions, including, but not limited to: phantom limb pain, sciatica, peripheral neuropathy, spinal stenosis, complex regional pain syndrome, and spinal cord injury. The treatment is usually administered after conventional treatments such as medication, physical therapy and injections have failed to reduce the patient’s pain. DCS does not cure the patient’s pain, but rather impairs the ability of the neuron’s to release pain signals. There are two types of dorsal column stimulation: trial stimulation and permanent implantation.
How is dorsal column stimulation performed?
There are three primary steps of the DCS procedure: the stimulating electrodes, an implantable pulse generator (IPG), and generator remote control. Trial stimulation is a two-step procedure that involves administering a local anesthetic through an epidural needle in the lower back using fluoroscopic imaging and then, through a small incision or radiographic guidance, inserting electrodes connected to an external stimulus via wires. Once the electrodes have been placed, the patient can use the generator remote control to administer low-frequency stimulation to the affected region. The patient can utilize the various settings of the remote control to test the effectiveness of the treatment. If after a week, the trial stimulation is successful in reducing the patient’s pain, permanent implantation of IPG is recommended.
Permanent implantation of a pulse generator is a more complex procedure that involves both a local numbing agent and an intravenous sedative. A small incision in the upper buttocks or abdomen to insert the IPG, which is either rechargeable or non-rechargeable. The neurosurgeon then inserts the stimulating electrodes through a needle into the appropriate region of the spine depending on where the patient is experiencing pain. The needle is then removed and the electrodes are secured using a silicone anchor. Once the electrodes are in place, the surgeon will utilize a tunneling device to guide and connect the electrodes to the IPG. Before cleaning, suturing, and dressing the site, the electrodes are tested for current. If the electrodes successfully stimulate the affected area, the patient is sent to the recovery room where the IPG is programmed and the patient is given the generator remote control. In total, the procedure takes 1 to 2 hours.
The procedure is typically well tolerated and the patient is sent home either the same or next day. Although the risk of surgical complications is low, displacement of the electrodes, infection, or discomfort at the IPG site can occur. The patient should avoid sitting for long periods of time, lifting anything heavy, bending down, engaging in strenuous activities or drinking alcohol for two weeks. The patient should contact their doctor if they develop a fever, experience prolonged nausea or vomiting, develop a rash, signs of infection, or fluid accumulation at the incision, or have a sudden onset of leg weakness or severe back pain.
Who is a good candidate for dorsal column stimulation?
It is crucial that curable causes of pain are ruled out before the patient pursues DCS. If several pain management options have been explored without success and the patient fits the criteria to undergo DCS, then the patient can be a good candidate for the procedure. A pain specialist will evaluate the type of physical condition, medications taken, and pain history to determine this. Most DCS candidates have had extremely severe pain and/or disability for over 3 months and usually one or more ineffective spinal surgeries.
What happens after the procedure?
Following the procedure, the patient has control of the frequency, width, and amplitude of the electric current and can decide to have the IPG and electrodes removed at any time without permanently damaging the spinal cord or nerves. Non-rechargeable IPGs need to be replaced every 2 to 5 years depending on how often the system is used, while rechargeable IPGs last 8 to 10 years longer than the latter.
DCS can be an effective and lasting treatment for individuals with severe chronic pain that have tried various conventional treatments to no avail. The treatment eliminates the need for excessive pain medication and allows patients to return to their normal daily lives and activities.
Author: Nawal Panjwani
Editor: Dave Thiagaram