Chronic regional pain syndrome (CRPS) takes a toll: Your nerve cells become hypersensitized to the point where everyday stimulation — like a draft of air or touch — causes an out-of-whack pain response.
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“Our bodies use acute pain as a warning system,” says pain management doctor Nagy Mekhail, MD, PhD. “If you sprain your ankle, the pain prevents you from putting your foot down and causing further injury. If you have chest pain while walking up two flights of stairs, it sounds an alarm to seek medical advice.”
But with chronic pain conditions like CRPS, pain loses its protective function and becomes a disease by itself. Thankfully, new treatments are being developed every day — like ketamine infusions and dorsal root ganglion stimulation (DRGS). Dr. Mekhail discusses DRGS, including who is most likely to benefit:
Q: What is the dorsal root ganglion?
A: Each segment of your spinal cord manages sensations for a specific area of the body. It’s like train lines heading out for different parts of the city. And the dorsal root ganglion (DRG) is the transportation hub: Every stimulus flows through the DRG, the nerve center of the spinal cord, on the way to the brain where it gets processed.
But the DRG is not just a sensation-relay station: It can filter pain stimuli to make them more or less intense.
Q: How does a DRG stimulator relieve pain?
A: The goal of DRGS is to make the nerve cells less sensitive. We use electric stimulation over the dorsal root ganglion to create an electric field, which slows the pain signals traveling from the limbs to the spinal cord then onto the brain. The electric field reprograms the nerve cells to decrease the super sensitivity that goes along with CRPS. This process normalizes the patient’s pain sensations.
Q: How do you implant the DRG stimulator?
A: The procedure takes 60-90 minutes. The team will:
- Give you light sedation.
- Numb the skin.
- Make a small incision beneath the skin in the buttocks or abdomen.
- Place a pulse generator — similar to a pacemaker — in the incision.
- Make tiny incisions to place four leads (wires) directly over the DRG associated with the pain-causing extremity.
When you move your foot or hand, the leads send minor electrical impulses to the DRG to block the pain signals from reaching the brain.
Q: Can you back up a beat and tell us why CRPS causes pain in the first place?
A: It seems with CRPS there is a structural change in the DRG cells. The result is pain that no longer needs a stimulus to start. The pain is constant for no rhyme or reason.
Q: How effective is DRG stimulation for CRPS treatment?
A: The initial study compared DRGS to spinal cord stimulation (also called SCS, which is similar, but doesn’t target the dorsal root ganglion). The results were impressive:
- 70 to 80% of them had 80% pain relief. (Only 52% of the SCS group had that level of pain relief.)
- Almost 93% of people who received DRGS had at least 50% pain relief.
Q: Who is eligible for this CRPS-pain destroyer?
A: DRGS is an invasive procedure — we implant an electrical stimulator into the body — so we prefer to try less invasive methods first, such as:
- Nerve blocks (a localized injection of steroids and pain relievers).
- Physical therapy.
If the pain is chronic and uncontrollable with other treatments, it’s worthwhile to consider DRGS because it works so well.
Q: What’s the catch? Are there risks we need to be aware of?
A: The risks are the same as with any procedure: a chance of bleeding or infection at the surgical site. But those are rare occurrences. There’s also a small chance that the wire that generates the electrical field will move and need to be repositioned.
The only other consideration is that the stimulator runs off a battery that gets implanted into the buttocks. The battery lasts five or six years, but eventually, it will need to be replaced. Fortunately, it’s a pretty quick procedure (15 to 20 minutes).
Q: Could DRGS work for someone that has chronic pain that isn’t CRPS?
A: In my practice, I’ve seen DRG stimulation help with other types of pain, including:
- Post-amputation pain.
- Neuropathies (nerve conditions) from peripheral vascular disease or diabetes.
- Any pain localized to a specific part of the body.