The real-world data collected in the PREDICT study has added to the evidence in favour of dorsal root ganglion (DRG) stimulation for the management of chronic intractable pain.
The PREDICT (A prospective post-market trial to evaluate DRG stimulation for the management of chronic intractable pain) study abstract was presented at the International Neuromodulation Society World Congress (INS; 27 May–1 June, Edinburgh, UK) by Sam Eldabe, (James Cook University Hospital, Middlesbrough, UK) and published in the congress abstract book.
According to Eldabe and colleagues, compared to conventional medical management, studies have provided evidence that traditional spinal cord stimulation can provide superior pain reduction. Nonetheless, a significant proportion of patients will not receive adequate pain relief. Stimulation of the dorsal root ganglion has emerged as an attractive alternative to spinal cord stimulation for managing chronic intractable pain.
The purpose of the PREDICT prospective observational study therefore is to evaluate real-world clinical outcomes of DRG stimulation for the treatment of chronic neuropathic pain. The study is looking at the effectiveness of DRG stimulation for the management of chronic pain, the effect of DRG stimulation on quality of life in the management of chronic pain, and the also effect of DRG stimulation on physical functioning in the management of chronic pain.
A total of 135 patients were consented and enrolled in study. Major inclusion criteria were met by 123 patients and included: chronic pain for at least six months, failed conservative treatments, and a baseline pain rating of ≥60mm on the Visual Analogue Scale (VAS) in the primary area of pain. Clinical indications included: peripheral nerve injury (PNI, n=44), complex regional pain syndrome (CRPS, n=31), postamputation pain (n=12), failed back surgery syndrome (FBSS, n=9), peripheral polyneuropathies (n=4), and other (n=21). Of these patients, 100 reported adequate pain relief during an intraoperative or external neurostimulator trial and proceeded to permanent implant. Pain relief, quality of life (EQ-5D), and mood (POMS) were compared between baseline and measurements made at the one-week post-implant and one, three, six, and 12-month follow-up.
“Across all patients and follow-ups, the overall response rate (≥30% reduction in the primary area of pain) was 68.6±2.9%. Patients’ clinical outcomes were further stratified based on their level of pain relief at the one-week follow-up. Of the patients, 93 with data available at that time point, mutually exclusive pain reduction categories and cohort proportions were: 80–100% (n=20, 22.7%), 50–79% (n=25, 28.4%), 30–49% (n=12, 13.6%), and 0–30% (n=31, 35.2%). The patients with ≥30% reduction reported durable outcomes, with pain reduction 47.3% at the 12-month follow-up. Significant improvement (141%) in EQ-5D was also sustained at the 12-month follow-up. A detailed indication and body region sub-analysis of each pain reduction category described above suggests that patients with CRPS or PNI respond particularly well, especially in the lower extremities,” the abstract reports.
Eldabe et al found that together, these converging real-world observational outcomes provide “additional evidence that DRG stimulation achieves the multi-modal goals of a chronic pain management strategy. The results from the current study may suggest clinical indications and regions of the body that are better suited for DRG therapy”, but, they add, additional retrospective analyses and prospective studies are needed to further advance the patient selection process for DRG therapy and inform predictions of responder rates.
Data previously published in the journal Pain confirmed the superiority of DRG stimulation therapy (from Abbott) over traditional spinal cord stimulation for patients suffering from complex regional pain syndrome. The data, which include both short-term and long-term data from the ACCURATE study, also suggested that DRG stimulation benefits patients’ total mood and activity levels.