Dorsal root ganglion stimulation

DRG stimulation targets focal neuropathic pain, especially lower-limb CRPS or causalgia in areas such as the foot; in ACCURATE it beat tonic dorsal column stimulation for treatment success with less postural paresthesia variation.

1. DRG stimulation is focused neuromodulation. Electrical stimulation of dorsal root ganglion neurons may modulate neuropathic pain signals, and CRPS guidance describes it as an advanced form of SCS for focal neuropathic pain ¹².
2. ACCURATE compared DRG with tonic SCS. The pivotal multicenter trial randomized 152 patients with lower-extremity CRPS or causalgia 1:1 to DRG or dorsal column stimulation, unblinded, with a temporary trial before permanent implant ¹.
3. Success needed relief without deficit. The primary composite endpoint at 3 months was at least 50% VAS reduction with no stimulation-related neurologic deficit; no patient had such a deficit ¹.
4. DRG won at 3 and 12 months. Treatment success was 81.2% with DRG versus 55.7% with SCS at 3 months, and superiority persisted at 12 months ¹.
5. Coverage is more precise. DRG patients had less postural variation in paresthesia and less extraneous stimulation in nonpainful areas, reflecting targeting of affected dermatomes that dorsal column leads reach poorly ¹.
6. Know the DRG-specific contraindication. Severe foraminal stenosis is an absolute contraindication for DRG placement, alongside active infection, coagulopathy, pregnancy and canal obliteration at the access levels ³.

Coagulopathy is an absolute contraindication for SCS and DRG lead placement and removal because epidural hematoma can cause neurologic compromise; manage antithrombotics before implantation, weighing the quantifiable risk of thrombotic events when therapy is interrupted ³.

• Device-related and serious adverse events did not differ between DRG and SCS arms in ACCURATE ¹.
• DRG stimulation also improved quality of life and psychological measures more than SCS ¹.
• ACCURATE trial stimulation lasted 3–30 days depending on each site's standard of care ¹.
• ACCURATE was designed as a noninferiority comparison of a composite safety and effectiveness endpoint ¹.
• Harden's CRPS guidance lists DRG stimulation among later-stage interventional considerations after 2017 and 2019 studies ².
• A pacemaker or implanted defibrillator does not preclude SCS or DRG stimulation; coordinate with cardiology ³.
• Relative contraindications also include immunosuppression, prior surgery at levels where leads will pass, and occupations or hobbies that raise lead-migration risk ³.
• Need for future MRI, depending on device compatibility, is a relative contraindication ³.

• Assuming DRG evidence covers broad axial back pain; ACCURATE enrolled focal lower-extremity CRPS and causalgia ¹.
• Extrapolating ACCURATE to upper-limb CRPS; it enrolled lower-extremity patients ¹.
• Overlooking severe foraminal stenosis at the target level ³.
• Requiring paresthesia that shifts with posture as proof of good coverage; DRG gave less postural variation ¹.