SLR - May 2014 - Randall Thomas
Reference: Kumar K, Rizvi S, Bnurs S. (2011). Spinal Cord Stimulation Is Effective in Management of Complex Regional Pain Syndrome Type I: Fact or Fiction? Neurosurgery (69) 566-580.
Scientific Literature Review
Reviewed By: Randall Thomas, DPM
Residency Program: Grant Medical Center, Columbus, OH
Podiatric Relevance: Complex Regional Pain Syndrome (CRPS) I is a debilitating neuropathic pain syndrome which commonly presents in the foot and ankle. The etiology remains unclear with the condition involving sensory, motor, and autonomic dysfunction and resultant trophic changes with severe, persistent pain and allodynia. CRPS I can present with or without trauma, usually minor trauma or during the post-op course, and develops through three stages ultimately leading to an atrophied limb commonly presenting in middle-aged patients with concomitant behavioral health conditions. This syndrome typically is recalcitrant to therapies including pharmacotherapy, peripheral nerve blocks, TENS units, chemical or surgical sympathectomy, physical and occupational therapy, and psychiatric therapy. The article presents a treatment option with Spinal Cord Stimulation (SCS) for long term improved pain, functional status, and quality of life. For improved patient care, foot and ankle surgeons should be aware of this treatment option and consider referral to neurosurgeons or pain specialists who perform SCS implantation.
Methods: This was a retrospective analysis of 25 patients over a mean follow-up period of 88 months who had SCS implantation for management of CRPS I. Inclusion criteria involved disease duration of at least six months, failed conventional medical management including a psychiatric evaluation. Patients whom trial stimulation failed and those lost to follow-up were removed from the study. Outcome measures were surveys including visual analog scale (VAS), Oswestry Disability Index (ODI), Beck Depression Inventory (BDI), EuroQoL-5D (EQ-5D), Short Form 36 (SF-36), and pain localization drawings as well as medication usage from the government pharmaceutical database. Evaluations were conducted at the time of surgery and follow-ups including three months, twelve months, and final (mean 88 months). Surgical technique included percutaneous lead implantation and surgical-paddle lead implantation.
Results: Pre-operative SCS implantation CRPS I survey responses compared to post-operative surveys demonstrated statistical significance (P < 0.001) with improvement in pain, functional status, and quality of life. Overall mean maximum improvement was recorded at three month follow-up. Pre-operative mean scores were: VAS 8.4, ODI 70 percent, BDI 28, EQ-5D 0.30, and SF-36 24, while post-operative three months mean scores were VAS 4.8, ODI 45 percent, BDI 15, EQ-5D 0.57, and SF-36 45. Final post-operative follow-up mean scores were VAS 5.6, ODI 50 percent, BDI 19, EQ-5D 0.57, and SF-36 40. Medication usage declined throughout the post-op course with mean 25 percent reduction in consumption of anticonvulsants, antidepressants, analgesics, and NSAIDs. The best results were observed in patients under 40 years old, stage I CRPS I, and those receiving SCS implantation within one year of symptom onset. SCS implantation did not prevent CRPS I development in other limbs. Twenty-two of 25 patients reported that they were satisfied with pain relief from treatment and would agree to treatment again.
Conclusions: SCS for patients with CRPS I improved long-term pain, functional status, and quality of life. Additionally patients status post SCS implantation used 25 percent less medication to control painful symptoms. SCS is a safe, reversible, cost-effective, and minimally invasive treatment for neuropathic pain. The literature supports SCS in failed back surgery, peripheral neuropathy, phantom limb pain, and peripheral vascular disease. The article supports SCS within one year of CRPS I symptoms with statistically significant improved outcomes in patients whose symptoms are recalcitrant to other therapies. Study limitations included lack of control group, blinding, a limited patient population, and reliability of subjective survey responses. The authors recommend referral to neurosurgery or pain specialists for evaluation and possible SCS early in the treatment course in order to maximize outcomes and successful rehabilitation.