If you suffer from neuropathic chronic pain, a new type of therapy called dorsal root ganglion stimulation, or DRG stimulation, could help you find minimally-invasive and highly-effective pain relief. It is most effective for patients with complex regional pain syndrome (CRPS).

For DRG stimulation, a pain specialist implants a small pulse generator under your skin, with four outward leads. These leads are then attached to the pulse generator and the painful area on your body. You then control the activation of small electrical impulses to these affected, painful areas. For patients with neuropathic pain, this can actually block the painful stimuli and provide very effective pain relief without medications. It also reduces the amount of paresthesias, or pins-and-needles feelings, that are associated with similar forms of pain relief.

Let’s talk some more about how this treatment works, the DRG stimulation procedure itself, and if it could work for you.

What is the dorsal root ganglion?

The dorsal root ganglion is a bundle of nerve cell bodies (i.e., a ganglion) located within the posterior region of various vertebrae along the spinal column. It is adjacent to the dorsal nerve root. The primary function of the dorsal root ganglion is to transmit information regarding your senses. As such, the dorsal root ganglion carries sensory neural signals from the peripheral nervous system to the central nervous system, which includes your spinal cord and brain.

Damage to or irritation of the dorsal root ganglion can lead to intractable symptoms of neuropathic pain that do not respond to typical treatments. This can lead to additional complications in the form of impaired functioning and pain. In these cases, more interventional approaches may be warranted, such as spinal cord stimulation or dorsal root ganglion stimulation.

How does DRG stimulation work?

Every year thousands of traditional spinal cord stimulation devices are implanted, which successfully treat conditions of intractable neuropathic pain, such as complex regional pain syndrome or failed back surgery.

Evidence has suggested that a new technique for neuromodulation is of the same dorsal root ganglion. The technique is nearly identical to spinal cord stimulation. And, it may also result in effective management of your chronic pain. Moreover, this DRG stimulation is considered to be an ideal alternative for some pain conditions, as it more effectively targets the specific pain location. It is especially useful for patients with complex regional pain syndrome (CRPS).

The first application of dorsal root ganglion stimulation was conducted in 1991 in a sample of rats. These studies found that dorsal root ganglion stimulation resulted in favorable effects on the inflammatory responses of these rats. Since this study, a number of trials of DRG stimulation have been conducted. As the Cleveland Clinic reports, the FDA approved DRG stimulation in February 2016 for the treatment of certain pain conditions in humans.

How Is Dorsal Root Ganglion Stimulation Performed?

As noted above, dorsal root ganglion stimulation is almost identical to the traditional spinal cord stimulation procedure; however, the dorsal root ganglion is targeted, rather than the spinal cord. Thus, dorsal root ganglion stimulation involves implanting electrodes, which are uniquely designed for use on this type of nerve bundle.

Along with the electrodes, a stimulation device is also implanted. This sends electrical impulses to the specified area of the dorsal root ganglion. This interrupts the transmission of pain signals from the peripheral nervous system, through the dorsal root ganglion, to the spinal cord and brain. And this prevents you from feeling as much pain.

Moreover, stimulating the nerve bundles with low intensity electrical impulses can replace the sensation with a pleasant tingling sensation, known as paresthesia. The device itself generates electrical impulses from a battery. You can program it using an external handheld device. These batteries need to be changed approximately every two to five years.

Watch a Texas doctor talk about the procedure below, along with the patient who found immense pain relief from it. This procedure was also made possible by a partnership with St. Jude Medical.

What Are DRG Stimulation Benefits?

By applying stimulation to the specific region of the dorsal root ganglion that is responsible for the pain, the benefits can be huge for patients. With DRG stimulation, there is:

• An opportunity to treat pain that hasn’t responded to other treatments
• Less need for medications
• Decreased parasthesia, or pins-and-needles, feelings
• Much more effective and targeted pain relief
• Less stimulation of the neural network in general

Another benefit of DRG stimulation is related to the fact that the dorsal root ganglion lacks the protective membrane that is found on other peripheral nerve fascicles. Instead, the dorsal root ganglion is surrounded by a permeable connective tissue coating. This makes it an ideal target for the application of neuromodulation.

In addition, the International Neuromodulation Society notes that for neuropathic pain:

“At 12 months, patients who responded to the therapy were reported to have both less discomfort, and also improved mood scores. The pain-relieving stimulation can be flexibly programmed so that if a patient prefers, the therapy can create a tingling sensation of paresthesia. In many patients relief occurs without parasthesia.”

Conditions Related to Dorsal Root Ganglion Stimulation

Damage to the dorsal root ganglion can occur either by direct injury to the nerve bundle itself or by compression from local inflammation or infection. Irritation or damage to the dorsal root ganglion can result in symptoms of chronic pain. DRG stimulation is most often used for:

• Intractable neuropathic pain
• Failed back surgery pain
• Complex regional pain syndrome (CRPS)
• Post-amputation pain

DRG Stimulation For CRPS

Complex regional pain syndrome (CRPS) is a malfunction of the nervous system that generally occurs after an injury or other trauma to the body. The nervous system overreacts to the injury and causes extreme pain that is out of proportion to the injury or trauma. Designing a treatment plan for CRPS can be very complicated, but there is new hope with DRG stimulation. DRG stimulation can specifically target pain associated with complex regional pain syndrome, even pain that has not responded previously to spinal cord stimulation or other treatments.

What is CRPS?

Complex regional pain syndrome is a pain condition that usually affects the arms and legs. There are two classifications of complex regional pain syndrome.

• CRPS-I is the classification when there is no verified nerve damage or trauma but the symptoms fit the syndrome.
• CRPS-II is the classification when there is verified nerve damage as the cause of the syndrome.

Complex regional pain syndrome symptoms can include:

• Prolonged and excessive pain, especially in the limbs
• Impairments in functioning
• Mild to severe alterations in skin temperature
• Sensitivity to cold and touch (allodynia)
• Rhythmic muscular contractions
• Changes in skin color
• Swelling of the affected limbs
• Headaches
• Stiffness in joints
• Unusual nail or hair growth
• Fixed limbs or jerky limbs
• Other uncomfortable sensations, including tingling, burning, or pins-and-needles

Complex regional pain syndrome occurs most often in women. The most common age range is 40 to 60 years old, but anyone can be affected by this complicated chronic pain condition. There is no clear understanding of why some people develop complex regional pain syndrome while others do not. There may be a limited genetic link, and those with autoimmune disorders may have a higher incidence. Because those with complex regional pain syndrome have higher levels of cytokines, there may also be a connection with depression, which also produces higher levels of cytokines.

Other CRPS treatments

Treatment for complex regional pain syndrome is as complex as the syndrome itself. Some traditional treatment options include:

• Counseling
• Nerve blocks
• Physical therapy
• Peripheral nerve stimulation
• Medications
• Biofeedback
• Spinal cord stimulation

While these treatments have been met with varying degrees of success depending on the patient, DRG stimulation has been producing some extraordinary results.

DRG stimulation for CRPS

With spinal cord stimulation, a small device is planted along the spinal cord to deliver electrical pulses to the nerves. These electrical pulses block pain signals and replace them with a gentle tingling sensation. DRG stimulation does largely the same thing but with one crucial difference: the target. And that’s why it’s been so effective for CRPS patients.

As noted, during the procedure electrodes are placed directly on the dorsal root ganglion, a bundle of nerves exiting the spinal cord to enervate specific parts of the body. This specific placement makes reaching formerly inaccessible areas, such as legs and arms, easier and more successful. Rather than blocking a general pain signal in the body, DRG stimulation directly addresses the areas of pain by targeting the source.

The results have been remarkable. In an ACCURATE clinical trial:

• Patients receiving DRG stimulation experienced much greater treatment success when compared to those patients receiving traditional SCS (74.2% vs. 53%)
• More patients did not experience an increase in paresthesia when they changed position with DRG stimulation, a side effect that can be unpleasant for some
• After 12 months, nearly 95% of patients receiving DRG stimulation reported better pain targeting without additional paresthesia, as compared to just over 61% of patients receiving traditional spinal cord stimulation

Are There DRG Stimulation Complications Or Side Effects?

Neural stimulation of the dorsal root ganglion does involve some risk, as the dorsal root ganglion device is surgically implanted.

Though very little is known about the consequences of injecting pain relieving medication within the dorsal root ganglion or the spinal cord, neuromodulation of the neural tissue within this area is believed to be safe and completely reversible. The procedure itself for implanting the device is regarded as safe. It is also conducted in such a way as to avoid inflammation or additional pain. In fact, many may return to normal activities of daily function within several days.

Risks associated with the condition are considered to be mild in nature and generally include:

• Minor bleeding at the site of the injections
• Infection
• Neural injury
• Local anesthetic systemic toxicity
• A reaction to the medication used during the procedure

Many of these risks can be avoided by talking about your risk factors and working with a highly-qualified doctor who has experience performing this procedure.

Could DRG Stimulation Work For You?

You may be a good candidate for DRG stimulation if any of these apply to you:

• You are experiencing refractory or intractable pain in the arms and legs
• Previous therapies for this pain have been unsuccessful
• You experience diabetic peripheral neuropathy
• You have not yet opted for more invasive surgical procedures, or you have had surgery that was unsuccessful
• The cause of your pain is not known or seems linked to injury or trauma elsewhere in the body

Complex regional pain syndrome can be complicated to manage, but DRG stimulation is a new way to approach this difficult pain condition.

Conclusion

Chronic neuropathic pain can be quite debilitating. Dorsal root ganglion stimulation can provide immense relief from these symptoms of chronic pain. This interventional approach is regarded as a relatively safe and effective procedure, with a low risk for side effects. The dorsal root ganglion is considered an ideal target for delivering pain relief, as the electrical stimulation can be applied to a more targeted area. Previous findings show that this procedure results in many favorable outcomes for patients with chronic neuropathic pain, with effects lasting up to a year or more.

If you’re interested in learning more about DRG stimulation, or finding a doctor who performs the procedure, click the button below. You’ll find a pain specialist who can help you relieve your pain as well as get back to your life.

References

1. Abram SE, Yi, J, Fuchs, A, Hogan QH. Permeability of injured and intact peripheral nerves and dorsal root ganglia. Anesthesiology 2006;105(1):146-153.
2. Sapunar, D, Kostic, S, Banozic, A, & Puljak, L. Dorsal root ganglion: A potential new therapeutic target for neuropathic pain. J Pain Res 2012;5:31-38.
3. Hu, SJ & Xing, JL. An experimental model for chronic compression of dorsal root ganglion produced by intervertebral foramen stenosis in the rat. Pain 1998;77(1):15-23.
4. Schu, S et al. Spinal cord stimulation of the dorsal root ganglion for groin pain: A retrospective review. Pain Practice 2015;15(4):293-299.
5. Liem, L et al. One-year outcomes of spinal cord stimulation of the dorsal root ganglion in the treatment of chronic neuropathic pain. Neuromodulation: Technology at the Neural Interface 2015;18(1):41-49.