Complex regional pain syndrome (CRPS) involves chronic pain disproportionate to inciting events with sensory, vasomotor, sudomotor, motor/trophic symptoms and signs 1. Spinal cord stimulation has been shown to be an effective treatment for CRPS with continued pain reduction and improvement in health-related quality of life 2, 3. Dorsal root ganglion (DRG) stimulation is recently approved by the FDA for the treatment of CRPS of the lower extremities. The DRG is a cluster of nerve cell bodies located in the dorsal root of a spinal nerve and plays a role in the development and maintenance of neuropathic pain 4,5.
Materials and Methods:
IRB approval and review determined to not be required. Patient consent was obtained for the submission of this case report.
Patient is a 35 year old female with no relevant past medical history who presented with left heel pain following a fall, with no fracture, and a small hematoma in her left heel. Over the next few weeks, the patient continued to have 9/10 throbbing pain in the left heel and developed allodynia, warm foot, hyperhidrosis, increased hair growth and decreased movement at ankle joint. On exam, her left foot was noted to have temperature difference of +2.2 F relative to right foot, decreased range of motion to -10 degrees dorsiflexion and 25 degrees plantar flexion, 3/5 strength with dorsiflexion, 4/5 with plantar flexion and inability to place weight on left heel. She was unable to stand for more than a few minutes and limited walking to less than one block with a walker. Treatment prior to pain clinic referral involved limb immobilization with controlled ankle movement boot, physical therapy and lumbar sympathetic blocks. In our clinic, patient underwent a series of six lumbar sympathetic blocks with 50-100% pain relief that was transient, lasting a few days to a week. A second series of three lumbar sympathetic blocks were performed followed by a 5 day lumbar epidural infusion with full return of pain at her six week follow up. She subsequently underwent DRG stimulation trial at left L4 and L5 nerve roots with 80% improvement in pain and ability to place pressure on left heel. Permanent implant was then performed at left L4, L5 and S1 nerve roots. Eight months after permanent implantation, patient continues to have 80% pain relief, ability to place weight on left heel and walk up to a quarter mile with a cane, mild residual allodynia and improvement of dorsiflexion and plantar flexion to neutral and 60 degrees respectively with 4/5 strength.
This case report illustrates the efficacy of DRG stimulation for the treatment of CRPS of the lower extremity. Previous study comparing dorsal column versus DRG stimulation have shown higher rate of treatment success and statistically significant improvement in general health and social functioning with DRG at twelve month follow up 5. This case report demonstrates improvement in objective functional outcomes such as range of motion, ability to walk longer distance and improved motor strength in addition to pain relief. The improvement in both pain control and functionality following DRG stimulation supports its continued role for the treatment of CRPS. This case study supports the need for additional studies to examine functional outcomes following DRG stimulation for patients with CRPS.
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5. Deer, TR et Al. Dorsal root ganglion stimulation yielded higher treatment success rate for complex regional pain syndrome and causalgia at 3 and 12 months: a randomized comparative trial. Pain. 2017 Apr;158(4):669-681.