Dorsal Root Ganglion Stimulation
Devices to stimulate the dorsal root ganglion (DRG) became available in the mid-2010s for treating chronic pain, particularly in areas that were hard to treat with traditional spinal cord stimulation, such as the hand, chest, abdomen, foot, knee or groin. (1)
The dorsal root ganglion (DRG) is a bundle of nerves that are located outside of the spinal cord. It is an easily accessible structure in the spine that plays a key role in the development and management of chronic neuropathic pain. It is a bundle of sensory nerve cell bodies within the epidural space. Each nerve root communicates to the dorsal root ganglion in a way that allows sensory messages from a defined area of the body. Therefore, applying stimulation to the DRG can permit focused therapy to a specific focal area.
DRG stimulation was initially used for some of the most challenging cases of complex regional pain syndrome (CRPS), a condition that causes severe pain and hypersensitivity in an extremity. Traditional spinal cord stimulation does not always provide adequate relief in CRPS and a DRG stimulator is much more specific for the affected body part. Today, we trial dorsal root ganglion stimulator systems as a therapy for neuropathic pain conditions that affect a specific body part such as a hip, knee, foot, groin, or rib.
When Dorsal Root Ganglion therapy should be considered
The DRG stimulator is well-suited for specific neuropathic conditions, which include CRPS, pelvic pain, groin neuralgia, extremity pain and other nerve pain involving isolated parts of the body.
Paresthesia-free SCS and DRG stimulators are new advances in neurostimulation and offer a non-destructive, reversible alternative to treat difficult nerve problems that fail to respond to more conservative care. Neurostimulation is far less invasive than traditional back surgery and is moving from a therapy of last resort to a therapy that may prevent the need for more aggressive treatments like surgery or nerve destruction.
DRG Stimulator Trial
The implantation process for the dorsal root ganglion (DRG) stimulator is very similar to the implantation of a typical SCS. Like the typical SCS, the implantation of a DRG stimulator begins with a trial.
A trial typically lasts 5 to 7 days. This procedure will be done at our ambulatory surgery center under light sedation.
The trial stimulator leads are temporarily implanted percutaneously (through the skin) using an epidural needle placed into the epidural space (the area surrounding the spinal cord). Once the leads are positioned within the epidural space, your physician will then stimulate the dorsal root ganglion, instead of the spinal cord.
The dorsal root ganglion is located at the side of the spine where the spinal nerve root exits to become a peripheral nerve. Your physician will know which DRG targets to stimulate based on the exact location of your pain. Once the leads are properly placed, they are then connected to a trial stimulator battery that is external.
During the trial, patients are able to control their device to alleviate pain. They can turn the device on and off as needed, they can turn the stimulation up or down for comfort, and there are multiple different programs they can use to help eliminate pain.
At the conclusion of the trial, the temporary leads will be removed and the patient and physician will determine if a permanent device should be implanted.
DRG Stimulator Implant
If you and your physician determine that the trial was successful, a permanent stimulator may be implanted.
For the permanent implantation, the procedure will be done at an ambulatory surgery center or hospital under conscious sedation directed by an anesthesiologist.
Two small incisions are made to complete the procedure. Permanent leads are implanted through the predetermined location in the epidural space.
Next, the leads are connected to the computer/battery unit called the internal pulse generator (IPG). Once the leads are connected, the IPG is implanted in the upper buttock region. The procedure takes around 30-40 minutes to complete.
When the procedure is finished, the IPG electrical pulses are programmed with an external control unit that the patient is able to use to control the system.
Patients are trained in how to use the control unit before leaving. Once again, the patient can use the control unit to turn the system on and off, adjust the stimulation level and switch between programs to alleviate their pain.
The patient is able to go home after the procedure when the programming is complete.