Dorsal Root Ganglion Stimulation in Experimental Painful Diabetic Peripheral Neuropathy: Burst vs. Conventional Stimulation Paradigm.

OBJECTIVES: Painful diabetic peripheral neuropathy (PDPN) is a long-term complication of diabetes mellitus (DM). Dorsal Root Ganglion Stimulation (DRGS) has recently emerged as a neuromodulation modality in the treatment of chronic neuropathic pain. The objective of this study was to compare the effect of burst DRGS (Burst-DRGS) and conventional DRGS (Con-DRGS) in an experimental model of PDPN.

MATERIALS AND METHODS: DM was induced in female Sprague-Dawley rats by intraperitoneal injection of streptozotocin (STZ, n = 48). Animals were tested for mechanical hypersensitivity (50% hind paw withdrawal threshold on Von Frey test) before, and 4 weeks after STZ injection. PDPN rats were then implanted with a unilateral bipolar lead at the L5 DRG (n = 22) and were stimulated for 30 min at days 2 and 3 postimplantation. Animals received Con-DRGS and Burst-DRGS in a randomized crossover design (n = 10), or received Sham-DRGS (n = 7) for 30 min, and were tested for mechanical hypersensitivity at baseline, 15 and 30 min during DRGS, and 15 and 30 min following DRGS. Five animals were withdrawn from the study due to electrode-related technical problems.

RESULTS: Con-DRGS and Burst-DRGS normalized STZ-induced mechanical hypersensitivity at 15 and 30 min during stimulation. A significant difference in terms of mechanical hypersensitivity was observed between both of the stimulated groups and the Sham-DRGS group at 15 and 30 min during stimulation. Interestingly, Burst-DRGS showed signs of a residual effect at 15 min after cessation of stimulation, while this was not the case for Con-DRGS.

CONCLUSIONS: Under the conditions tested, Con-DRGS and Burst-DRGS are equally effective in attenuating STZ-induced mechanical hypersensitivity in an animal model of PDPN. Burst-DRGS showed signs of a residual effect at 15 min after cessation of stimulation, which requires further investigation.