Dorsal Root Ganglion Stimulation in Experimental Painful Diabetic Polyneuropathy: Delayed Wash-Out of Pain Relief After Low-Frequency (1Hz) Stimulation

Very Low Frequencies Maintain Pain Relief From Dorsal Root Ganglion Stimulation: An Evaluation of Dorsal Root Ganglion Neurostimulation Frequency Tapering

“…Low‐frequency DRG‐S did, however, result in a delayed wash‐out effect that was not observed at the higher frequencies. This led the authors to conclude that low frequency 1 Hz DRG‐S may represent a more optimal stimulation frequency compared to the higher settings studied (41).…”

Mechanisms for the Clinical Utility of Low-Frequency Stimulation in Neuromodulation of the Dorsal Root Ganglion

“…Electro‐acupuncture and transcutaneous stimulation demonstrate that stimulation at 2–10 Hz recruits mu opioid receptor pathways while higher frequencies (100 Hz) elicit delta opioid receptor system activation (42–45). In allodynic animal models, SCS and DRG‐S both increase paw withdrawal thresholds, suggesting pain relief (46–49). Additionally, DRG‐S at 1 Hz, 20 Hz, and 1000 Hz were equally efficacious in blocking pain in rats, with 1 Hz having a longer wash out period (49).…”

“…In allodynic animal models, SCS and DRG‐S both increase paw withdrawal thresholds, suggesting pain relief (46–49). Additionally, DRG‐S at 1 Hz, 20 Hz, and 1000 Hz were equally efficacious in blocking pain in rats, with 1 Hz having a longer wash out period (49). These studies underscore Ikeda et al's findings that very low‐ and high‐frequency electrical stimulation to the same primary afferent fibers can trigger different pathways or mechanistic responses within the spinal circuits (50).…”

Neuromodulation of the dorsal root ganglion in experimental chronic neuropathic pain

“…Third, Con-SCS is often unable to satisfactory and specifically stimulate difficult-to-reach areas, such as the extremities or the groin. Fourth, placement of the leads on top of the dorsal columns makes this therapy susceptible to postural variations due to changes in distance between stimulation lead and stimulation target, leading to unpleasant paresthesias and/or overstimulation [61]. Last, the energy consumption of SCS is relatively high, as there is significant energy loss to the local environment such as the cerebrospinal fluid (CSF), before the electrical energy (charge) reaches the spinal cord dorsal columns.…”

“…Because of the importance of the dorsal columns in somatic sensation, and as the origin of these unmyelinated fibers is still not fully understood, it is extremely important to understand where these fibers originate. Although the unmyelinated fibers may belong to various categories including proprioceptive, corticospinal or fibers descending from cells in the nucleus gracilis or cuneate [59,61], unilateral dorsal root transection revealed that a significant fraction of the unmyelinated fibers in the fasciculus gracile ascend, presumably to the nucleus gracilis in the brain stem, and also that a significant number of these fibers branch [62]. Moreover, based on pharmacological intervention studies it is strongly suggested that, at least at cervical levels, a subset of these unmyelinated fibers might be nociceptive and involved in noxious processing [63].…”