Dorsal Root Ganglion Stimulation for the Management of Chronic Neuropathic Pain: A Retrospective Case Series during Four Years follow-up in a Single Center

Abstract

Objectives: The dorsal root ganglion (DRG) is involved in the transduction of pain signals to the central nervous system (CNS) and undergoes a number of physiopathological changes during chronic pain. The purpose of this data collection was to evaluate the long-term safety and efficacy of DRG stimulation for the treatment of chronic pain and its impact on functional aspects. Materials and Methods: Forty-four subjects with non-reactive chronic neuropathic pain syndrome were implanted with DRG stimulation. Patients were evaluated at baseline as well as at 15, and 30 days, and at 3, 6, 12, 24, 36 and 48 months after medical intervention/surgery using the Visual Analogic Scale (VAS), which measures pain intensity, and the Oswestry Scale, for the estimation of disability (ODI). Results: After four years of simulation, VAS and ODI showed a statistically significant reduction throughout the follow-up period. The average pain relief obtained after 48 months of treatment was 74.1% ± 3.4. Conclusion: The results of this data collection demonstrate the feasibility of DRG stimulation, the correspondence between the clinical indications at the DRG implant and what is commonly found in the literature on this technique.(18,20) Patients defined as clinical responders to DRG stimulation and so implanted with definitive IPG showed a sustained and long term efficacy. Eight patients had previously been implanted with a traditional SCS without any clinically relevant efficacy; they were then explained for unsatisfactory results. Six of them (75%) were later implanted with DRG, with long-term effectiveness. Another advantage of this therapy is the absence of positional effects and lead migration. The adverse events proved to be independent of the anatomical level of insertion; moreover, this series of cases show a lower incidence of lead migration than reported in the literature. In summary, DRGs have been ignored for too long, probably due to the technical difficulty of reaching their deep, almost extra-spinal anatomical position.