Posterior root ganglion stimulation (DRGS) may be an effective treatment for people with non-complex regional pain diagnoses of regional pain syndrome, although patients should be assessed on a case-by-case basis. This is evident from research published in Neuromodulation.
Given the increasing evidence that DRGS could be an option for treating multiple pain conditions in addition to complex regional pain syndrome, researchers conducted a systematic review of clinical experience with DRGS for treating non-complex regional pain syndromes in chronic pain.
Studies published after December 31, 1999 could be included. An initial search found 1,811 reports, and 28 studies published between 2012 and 2020 involving 354 patients were included in the final analysis.
The researchers categorized reports based on pain etiology: axial back pain, pelvic pain, other focal peripheral neuropathies, and multiple concomitant causes of pain. All reports included had a low level of evidence and contained observational data. Studies were considered successful if patients had a baseline pain reduction of more than 50%.
Six studies focused exclusively on back pain (n = 78 patients). Five of these reports were case series with follow-up times between 6 weeks and 26 months. Five studies showed a pain reduction of more than 50% compared to the baseline at the time of the last follow-up examination. Complications included 5 participants with lead migration and 1 participant with pain in the device pocket.
7 studies (4 case series, 3 case reports; n = 59 patients) reported pelvic and groin pain, including chronic pelvic pain, pudendal neuralgia, coccydynia, persistent neuropathic groin pain, and persistent chronic bilateral testicular pain.
Follow-up times ranged from 7 days to 12 months. In 5 of the studies, patients generally responded well to DRGS treatment and showed a pain reduction of more than 70% at the final follow-up visit.
Nine studies concerned other focal peripheral neuropathies (6 case series, 3 case reports; n = 65 patients). One study included participants who met the criteria for complex regional pain syndrome II.
Follow-up ranged from 5 to 36 months and pain syndromes included phantom pain, peripheral neuropathic pain post-Lyme disease, anterior cutaneous nerve entrapment, postoperative knee pain, neuropathic pain post peripheral nerve injury, diabetic peripheral neuropathy, hematuria of refractory lumbar pain syndrome, and idiopathic lumbar pain syndrome Small fiber neuropathy of the left foot. Eight studies showed pain relief of 50% or more, and complications occurred in 18 patients.
The remaining 5 studies focused on multiple chronic pain causes (n = 147 participants). Four studies included people diagnosed with complex regional pain syndrome (n = 51). All 5 reports showed a reduction in average pain of more than 50% over the range of 3 days to 18 months at the time of the last follow-up. This group of studies had the most complications. In 4 studies, 81 adverse events were reported including transient motor stimulation, infection, pocket pain, and device reprogramming.
Of the studies, 20 included a secondary outcome measure, focusing primarily on physical function, quality of life, and reducing pain reliever use.
“Previous research has shown that DRG is a primary target for relieving and reducing chronic pain because of its modulation of signal transmission between the periphery and the CNS via the T-junction,” the researchers wrote. “While only admitted for treatment [complex regional pain syndrome]In 28 reports, we found supportive evidence of DRGS … with a variety of pain syndromes in all reports. ”
Despite these positive results, evidence from well-designed, high-level studies and recommendations from experts on the Consensus Committee is needed to validate this treatment modality.
“It may be useful and appropriate to screen patients for DRGS candidacy on a case-by-case basis, especially if they have focal pain syndromes that are unresponsive to non-interventional measures and may not be ideal candidates for other forms of neuromodulation,” the researchers concluded .
Disclosure: One study author declared his affiliation with the pharmaceutical industry. For a full list of the authors’ information, see the original reference.
Stelter B., Karri J., Marathe A., Abd-Elsayed A. Dorsal root ganglion stimulation for the treatment of non-complex regional pain syndromes associated with chronic pain syndromes: a systematic review. Neuromodulation. Published online January 26, 2021. doi: 10.111 / ner.13361
This article originally appeared on Clinical Pain Advisor