Dorsal Root Ganglion therapy, DRG for short, is a neuromodulatory therapy which treats chronic pain. Dorsal root ganglions are collections of nerve cells that reside on both sides of each vertebrae at the dorsal root of the spinal nerve. There are approximately 1500 neurons at each dorsal root ganglion. They serve as the gateway to pain between various nerves in the body including the brain and spinal cord. DRG therapy communicates with these sensory neurons and interfere with the pain messages they are sending to the brain. This interference inhibits the pain signals from being sent, therefore, inhibiting the pain. 

DRG therapy uses an implantable power generator, similar a miniature pacemaker battery, and up to four electrical leads that are fed through the epidural space. These leads are fed using the same fluoroscopic guidance method as spinal cord stimulation therapy. Once fed to the proper location, the leads are placed in an S shape known as the S shape relief loop typically targeting the sacral and lumbar dorsal root ganglia. The three ligaments surrounding the dorsal root ganglia posteriorly, inferiorly, and superiorly, allow for the stabilization of the leads. Patients are provided with a handheld controller and given the opportunity to switch between different stimulation settings and control their own pain. The difference between DRG therapy and spinal cord stimulation therapy is the precision that DRG therapy offers. Spinal cord stimulation provides a broad spectrum coverage for radicular pain while DRG therapy is able to provide a more precise delivery of analgesia. DRG therapy allows for pain relief to be delivered to the lower back, the groin, even one single toe. 

DRG Therapy and CRPS 

CRPS, or complex regional pain syndrome can be a very taxing pain condition. Nerve cells become hypersensitized and things like a draft of air or a simple touch can cause an abnormal pain response. With CRPS, pain loses its protective function to alert us when something is physically wrong and becomes a disease itself. DRG therapy works to decrease the hyper sensitivity within the nerve cells that comes along with CRPS. This process normalizes the patient’s pain sensations. DRG therapy has proven to be very successful for patients with CRPS. One study compared DRG therapy to spinal cord stimulation therapy in patients with CRPS.  70%-80% of the patients had 80% pain relief with DRG therapy, while 52% had the same level of relief with spinal cord stimulation. Almost 93% of the patients who received DRG therapy reported at least 50% pain relief. 

DRG Therapy has proven to be successful but is still an invasive procedure due to the electrical leads being implanted. It is recommended to try noninvasive or less invasive methods first before electing to undergo DRG therapy. However, if there is no relief obtained from more traditional treatments, DRG therapy may be a viable method for patients with CRPS.