Understand · Chapter 05
When the pain is in one place, and nothing else can reach it
The foot. The knee. The groin. Regions that conventional spinal cord stimulation has historically covered poorly, where paresthesia drifts with posture and coverage is difficult to hold. Dorsal root ganglion stimulation targets a different structure entirely — and in the right patient it does something no other therapy does.
What You'll Learn
Approx. 9 min read- What the dorsal root ganglion is and why it is a useful target
- How DRG stimulation differs technically from conventional SCS
- Which pain patterns are best suited to it
- What the ACCURATE trial demonstrated
- The technical demands and risks specific to DRG placement
- Why it is a distinct therapy, not a variation on SCS
The Target
What the dorsal root ganglion is
Every sensory nerve fibre travelling from your body toward your spinal cord passes through a dorsal root ganglion — a small, discrete cluster of sensory nerve cell bodies sitting just outside the spinal cord in the intervertebral foramen, the bony opening where the nerve root exits the spine.
This makes it a remarkable target for two reasons. First, it is somatotopically organised: each DRG serves a specific, predictable region of the body. Stimulate the L5 DRG and you affect the territory L5 supplies — not the territory above or below. Second, it sits in a location with very little cerebrospinal fluid around it, unlike the dorsal columns of the spinal cord.
That second point has a consequence patients notice immediately. In conventional SCS, the layer of CSF between the lead and the spinal cord varies as you change position — thicker when you lie down, thinner when you stand — so the intensity of stimulation shifts with posture. At the DRG there is minimal CSF, so the therapy is far more positionally stable.
The Differences
How DRG stimulation differs from conventional SCS
Precision of coverage
Because each ganglion maps to a defined territory, coverage can be focused on one region — a single foot, one knee, the groin — without spilling into areas that do not hurt.
Positional stability
Minimal cerebrospinal fluid at the target means far less variation in stimulation intensity when you change from lying to sitting to standing.
Lower energy requirement
Proximity to the target and the absence of a CSF buffer mean therapeutic effect is generally achieved at lower amplitudes than conventional SCS.
Reaches difficult territories
The foot, groin and knee are notoriously hard to cover reliably with dorsal column stimulation. These are exactly where DRG has its strongest role.
The Procedure
Technically demanding, and that matters
A DRG lead is placed through a needle into the epidural space, then steered laterally into the intervertebral foramen so that its contacts sit adjacent to the target ganglion. The lead incorporates a strain relief loop designed to accommodate movement without transmitting tension to the tip.
This is a more technically demanding placement than a conventional epidural lead, and it should be said plainly: outcomes with DRG stimulation are more operator-dependent than with conventional SCS. The Neuromodulation Appropriateness Consensus Committee has published dedicated best-practice guidance for exactly this reason, covering patient selection, technique and complication avoidance.
As with conventional SCS, a trial is performed before any permanent implant. The trial leads are placed the same way, the therapy is tested for about a week, and the leads are removed in the office afterwards.
Indications
Where DRG stimulation fits
Primary indication
Complex regional pain syndrome
CRPS types I and II of the lower extremities — the population studied in the ACCURATE trial and the core FDA indication in the United States. CRPS of a foot or lower leg is the classic scenario in which DRG outperforms conventional stimulation.
Primary indication
Causalgia
Persistent burning pain following a peripheral nerve injury, in the lower limbs. Focal, neuropathic and anatomically defined — the profile DRG is built for.
Focal post-surgical neuropathic pain
Persistent pain in a defined territory after hernia repair, knee replacement or other surgery, where the pain follows a specific nerve distribution. Assessed individually against current labeling.
Where conventional SCS has failed on coverage
Patients whose SCS provided relief in some areas but never adequately covered a specific focal region. DRG can sometimes address the gap directly.
The ACCURATE trial
ACCURATE was the pivotal prospective randomized comparative trial of DRG stimulation versus conventional spinal cord stimulation in patients with complex regional pain syndrome and causalgia of the lower extremities.
It supported the FDA approval of DRG stimulation in the United States and remains the anchor of the evidence base. It is notable as one of the relatively few head-to-head randomized comparisons between two active neuromodulation therapies rather than against placebo or medical management.
Trade-offs
The honest limitations
DRG stimulation is not a better version of spinal cord stimulation. It is a different tool for a different problem, and in the wrong patient it is the worse choice.
Its strength — precise, focal coverage — is also its limitation. A patient with broad, bilateral, back-and-both-legs pain is generally better served by conventional SCS. Covering multiple large territories with DRG leads is possible but is not what the therapy is designed around.
Placement is technically harder, with a somewhat different complication profile, including the possibility of lead fracture or migration within the foramen. And the indication in the United States remains narrower than that of conventional SCS.
There is also a smaller field of manufacturers. In practical terms, DRG stimulation in the U.S. means Abbott's platform, which shapes the surrounding decisions about generator, waveform and MRI conditions.
Common Questions
Questions about DRG stimulation
Take the next step in understanding your options
Read how candidacy is assessed, then discuss your history and imaging with your own clinician. This site does not arrange evaluations.