Table 5.
Summary of studies on idiopathic peripheral neuropathy and polyneuropathy
| Author, year | Country | Study design | Study funding/COI | No. of subjects | Diagnosis | Mean age (years) | Intervention | Outcomes |
|---|---|---|---|---|---|---|---|---|
| Deer et al. (2013) [57] | USA | Prospective non-comparative | Sponsored by Spinal Modulation, Inc. | 10 | Chronic intractable pain of the trunk and/or limbs |
Male: 52 ± 5 Female: 39 ± 4 |
DRG-S | There was a mean 70% reduction in pain. 8/9 pts had > 30% reduction in pain, and 7/9 pts reduced their pain medication utilization. Pain relief in leg, back, and foot was also observed. No device-related AEs were reported |
| Maino et al. (2017) [58] | Switzerland | Case report | No funding | 1 | Painful small fiber neuropathy | 74 | DRG-S | After a positive 10-day trial, a permanent stimulator was implanted. At 20 months post-implantation, pt continued to have stimulation-induced paresthesia covering the entire painful area. Pain decreased from 8 to 4 |
| Mata et al. (2020) [59] | USA | Case report | No funding | 1 | Frostbite with refractory burning and pain in the foot | 65 | DRG-S | Pt had significant improvement in his pain and continued to have 90% improvement at 2 years. He was weaned off oxycodone, amitriptyline, and gabapentin; his fentanyl patch was lowered to 25 μg every 72 h and he was able to return to work |
| Kretzschmar et al. (2021) [60] | Germany | Case report | No funding | 1 | Central post-stroke pain in the lower extremity after medullary infarction | 53 | DRG-S | Pt was successfully weaned off opioids after implantation |
| Koetsier et al. (2021) [55] | Switzerland | Prospective non-comparative | No funding | 9 | Chronic painful polyneuropathy in the lower limbs | 63.2 ± 8.7 | DRG-S L5 and S1 | 8/9 pts had a successful DRG-S trial, and 7 underwent implantation. Daytime pain decreased from a median (IQR) NRS score of 7.0 (5.9–8.3) to 2.0 (1.0–3.5) and 3.0 (1.6–4.9) in the 1st week and at 6 months after implantation. Similar effects were observed for nighttime and peak pain scores |
| Grabnar et al. (2021) [61] | USA | Case report | No funding | 1 | CIPN | 50 | DRG-S | DRG-S resulted in 100% pain relief which persisted at 3 years after placement |
| Roybal et al. (2021) [62] | USA | Case report | No funding | 1 | Acute neuropathic pain from acute HZ infection | 61 | DRG-S left S1 dorsal | After 1 month of pain refractory to treatment, DRG-S significantly decreased pain despite ongoing cutaneous manifestations of HZ |
| Horan et al. (2021) [63] | Denmark | Cohort, multicenter | No funding | 43 | Chronic neuropathic pain in upper extremity, lower extremity, or trunk |
Trial: 43 ± 10 Implant: 42 ± 10 |
DRG-S | 33 subjects were implanted. At 12 months, 58% of pts were still implanted; 42% had fully functional systems. NRS score was reduced from mean 6.8 to 3.5 and worst NRS score was reduced from mean 8.6 to 6.0 at 12 months follow-up. PCS decreased from mean of 32 to 15. Thirteen pts experienced complications related to leads (39% of implanted systems). In 4 pts (12%), lead removal left fragments in the root canal, and 3 pts suffered permanent nerve damage during attempts to replace broken leads |
AE adverse event, CIPN chemotherapy induced peripheral neuropathy, COI conflict of interest, DRG-S dorsal root ganglion stimulation, HZ herpes zoster, IQR interquartile range, NRS numerical rating scale, PCS pain catastrophizing scale, pts patients, SCS spinal cord stimulation