Intermittent Dosing of Dorsal Root Ganglion Stimulation as an Alternate Paradigm to Continuous Low-Frequency Therapy

Dorsal Root Ganglion (DRG) is a novel target of neuromodulation that's use has grown as a proven effective treatment in chronic painful conditions. Studies examining tonic, paresthesia-based dorsal column stimulation have demonstrated plateauing or diminishing effects after extended time periods. Although not yet studied in DRG stimulation due to its relative infancy, the possibility of decreased pain relief over time very much exists. In order to mitigate the potential for waning pain relief over time, other paradigms of stimulation within the framework of DRG therapy must be evaluated.

Intermittent dosing (ID) refers to the cycling of stimulation, in which there is a designated time period of stimulation being active (ON) and inactive (OFF). Previous studies have demonstrated the safe and effective use of intermittent dosing using spinal cord stimulation (SCS).9,10 In 2020, Deer et al. reported the efficacy of intermittent dosing of Burst stimulation with settings ranging from 30 seconds ON and 90 seconds OFF, to 30 seconds ON and 360 seconds OFF in SCS.10 However, no studies have examined the use of ID in DRG stimulation. Furthermore, a pre-clinical study by Chao et al. 2020 showed that DRG field stimulation delivered at 20 Hz continuously abated transmission of action potentials in most C-type fibers and 50% of Aδ fibers. Conversely, DRG field stimulation delivered at 5 Hz consistently evoked action potentials in Aβ, Aδ, and C type fibers, suggesting that this frequency may have greater potential to mitigate pain11. Nevertheless, translation of these results to clinical practice have yet to be studied.

Patients with chronic pain secondary to CRPS or other chronic neuropathic who have responded to DRG stimulation originally and have undergone permanent DRG stimulator implantation delivered by the Abbott PROCLAIM Dorsal Root Ganglion Neurostimulator System, have had the system in place for at least 1 year, utilizing continuous tonic therapy, reporting minimum 50% pain relief in the targeted area, will be randomized to 1 of 2 study arms, in a single-blinded, 1:1 fashion:

1. High ID Arm: DRG stimulation therapy at 20 Hz frequency for 30 seconds ON, 90 seconds OFF
2. Low ID Arm: DRG stimulation therapy at 5 Hz frequency for 30 seconds ON, 90 seconds OFF

Based on the stimulation frequency each patient receives the stimulation amplitude will be adjusted accordingly to remain in the therapeutic dosing window for each patient.