Spinal Cord Stimulation for the Treatment of Neuropathic Pain after Spinal Cord Injury: A Systematic Review and Report of a Novel Case
Background: Neuropathic pain (NP) after spinal cord injury (SCI) is a commonly reported symptom in the SCI patient population, with refractory cases leading to high health care utilization exceeding $20,000 per patient compared to patients with SCI not experiencing refractory NP.(1) NP in SCI is associated with higher risk for depression, poorer function and quality of life, and worse overall health status. (2) In refractory cases, advanced interventional therapies including spinal cord stimulation (SCS) offer an effective treatment for SCI-related NP. A previous literature review performed in 2009 identified 27 reports involving 244 patients with SCI undergoing SCS therapy, and no clinical trials examining the use of SCS in SCI-related NP. (3)(4) Our systematic review identified 17 reports involving patients with SCI treated with SCS for neuropathic pain published within the past ten years, none of which included dorsal root ganglion (DRG) stimulation. To illustrate the use of this therapy in this patient population, we also provide the description of a case in a patient with refractory NP successfully treated with DRG stimulation.
Methods: Ovid databases were searched from 2008 through February 2018 with help from a medical reference librarian in accordance with PRISMA guidelines. After duplicate removal 234 articles were reviewed by two independent reviewers (CH and MDJ), and any discrepancies were resolved after discussion. IRB approval was waived for the report of this novel case involving a single subject, whose consent was provided for this presentation.
Results: This systematic review identified 17 reports including 14 conference abstracts and 3 published case reports. None reported the use of DRG stimulation. These findings highlight the paucity of published literature in this area and the need for research examining the effectiveness of SCS in the treatment of SCI-related NP.
A 60 year old male with incomplete tetraplegia presented to our clinic with refractory NP. He was unable to return to his vocation of flying due to severe pain, and Federal Aviation Administration requirements prohibit using any pain medications. He successfully underwent DRG stimulation, has returned to flying, and reports greater than 60% improvement in pain and function.
Conclusions: There have been no randomized controlled trials published on SCS for neuropathic pain in SCI in the 46 years since the first report (5) of this application of implanted therapies. The use of SCS for the treatment of NP in SCI remains poorly studied. The lack of rigorous studies examining the safety and efficacy of these implantable therapies for the treatment of refractory NP in SCI highlight an opportunity for clinical trial development.
For patients with SCI whose injury may preclude safe placement of dorsal column SCS devices, DRG stimulation remains a viable option if otherwise indicated for distal limb pain in patients with refractory NP.
Barriers to development of clinical trials studying this indication include cost and recruitment, but as highlighted by the results of our systematic review and exemplified by this case presentation, the efficacy of SCS in the treatment of SCI-related neuropathic pain is an important question with high clinical salience deserving of rigorous scientific inquiry.