Dorsal Root Ganglion (DRG) Stimulation in the Treatment of Phantom Limb Pain (PLP).
OBJECTIVE
Phantom limb pain (PLP) is a neuropathic condition in which pain is perceived as arising from an amputated limb. PLP is distinct from, although associated with, pain in the residual limb and nonpainful phantom sensations of the missing limb. Its treatment is extremely challenging; pharmaceutical options, while commonly employed, may be insufficient or intolerable. Neuromodulatory interventions such as spinal cord stimulation have generated mixed results and may be limited by poor somatotopic specificity. It was theorized that dorsal root ganglion (DRG) neuromodulation may be more effective.


METHODS
Patients trialed a DRG neurostimulation system for their PLP and were subsequently implanted if results were positive. Retrospective chart review was completed, including pain ratings on a 100-mm visual analogue scale (VAS) and patient-reported outcomes.


RESULTS
Across eight patients, the average baseline pain rating was 85.5 mm. At follow-up (mean of 14.4 months), pain was rated at 43.5 mm. Subjective ratings of quality of life and functional capacity improved. Some patients reduced or eliminated pain medications. Patients reported precise concordance of the paresthesia with painful regions, including in their phantom limbs; in one case, stimulation eliminated PLP as well as nonpainful phantom sensations. Three patients experienced a diminution of pain relief, despite good initial outcomes.


CONCLUSIONS
DRG neuromodulation may be an effective tool in treating this pain etiology. Clinical outcomes in this report support recent converging evidence suggesting that the DRG may be the site of PLP generation and/or maintenance. Further research is warranted to elucidate mechanisms and optimal treatment pathways.
The James Cook University Hospital, Middlesbrough, UK.
Sam
S
Eldabe
Rijnland Ziekenhuis, Leiderdorp, The Netherlands.
Katja
K
Burger
Rijnland Ziekenhuis, Leiderdorp, The Netherlands.
Heinrich
H
Moser
NC Praxis Rothenbaum, Hamburg, Germany.
Daniel
D
Klase
University of Dusseldorf, Dusseldorf, Germany.
Stefan
S
Schu
Akademiska sjukhuset, Uppsala, Sweden.
Anders
A
Wahlstedt
Clinique et Maternité Sainte-Elisabeth, Namur, Belgium.
Bernard
B
Vanderick
Clinique et Maternité Sainte-Elisabeth, Namur, Belgium.
Eric
E
Francois
Spinal Modulation, Inc., Menlo Park, CA, USA.|College of Medicine, University of Illinois, Peoria, IL, USA.
Jeffery
J
Kramer
Spinal Modulation, Inc., Menlo Park, CA, USA.
Jeyakumar
J
Subbaroyan
D000328:Adult; D000368:Aged; D004599:Electric Stimulation Therapy / Q000379:methods*; D005260:Female; D005471:Fluoroscopy; D005500:Follow-Up Studies; D005727:Ganglia, Spinal / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010591:Phantom Limb / Q000628:therapy*; D012189:Retrospective Studies; D016896:Treatment Outcome; D064232:Visual Analog Scale
Chronic pain; deafferentation; dorsal root ganglion (DRG); neuropathic pain; spinal cord stimulation (SCS); visual analog scale (VAS)