Neuromodulation : journal of the International Neuromodulation Society
-
Various spinal cord stimulation (SCS) modes are used in the treatment of chronic neuropathic pain disorders. Conventional (Con) and Burst-SCS are hypothesized to exert analgesic effects through different stimulation-induced mechanisms. Preclinical electrophysiological findings suggest that stimulation intensity is correlated with the effectiveness of Burst-SCS. Therefore, we aimed to investigate the relation between amplitude (charge per second) and behavioral effects in a rat model of chronic neuropathic pain, for both Conventional Spinal Cord Stimulation (Con-SCS) and biphasic Burst-SCS. ⋯ Biphasic Burst-SCS requires significantly more mean charge per second in order to achieve similar pain relief, as compared with Con-SCS, in an experimental model of chronic neuropathic pain.
-
Multicenter Study
Effective Relief of Pain and Associated Symptoms With Closed-Loop Spinal Cord Stimulation System: Preliminary Results of the Avalon Study.
Conventional spinal cord stimulation (SCS) delivers a fixed-input of energy into the dorsal column. Physiologic effects such as heartbeat, respiration, spinal cord movement, and history of stimulation can cause both the perceived intensity and recruitment of stimulation to increase or decrease, with clinical consequences. A new SCS system controls stimulation dose by measuring the recruitment of fibers in the dorsal column and by using the amplitude of the evoked compound action potentials (ECAPs) to maintain stimulation within an individualized therapeutic range. Safety and efficacy of this closed-loop system was evaluated through six-month postimplantation. ⋯ The majority of subjects experienced profound pain relief at three and six months, providing preliminary evidence for the effectiveness of the closed-loop SCS system. The exact mechanism of action for these outcomes is still being explored, although one likely hypothesis holds that ECAP feedback control may minimize recruitment of Aβ nociceptors and Aδ fibers during daily use of SCS.
-
Traditional spinal cord stimulation (SCS) requires that paresthesia overlaps chronic painful areas. However, the new paradigm high-frequency SCS (HF-SCS) does not rely on paresthesia. ⋯ To fully understand and utilize paresthesia-free HF-SCS, mechanistic study and translational research will be very important, with increasing collaboration between basic science and clinical communities to design better trials and optimize the therapy based on mechanistic findings from effective preclinical models and approaches. Future research in these vital areas may include preclinical and clinical components conducted in parallel to optimize the potential of this technology.
-
Spinal cord stimulation (SCS) for the treatment of lower extremity pain is believed to the result of increased activity in the descending inhibitory and decreased activity in the ascending excitatory tracts. Evidence suggests that the analgesia afforded by SCS may be altered using certain neuropathic pain medications that also modulate neurotransmitters in these sensory tracts. We hypothesize that neuropathic pain medications may alter the response to SCS therapy. ⋯ The use of neuropathic pain medications did not change the odds of either a successful SCS trial, or of experiencing a 50% reduction in pain at one year. The association between higher opioid doses and greater odds of a 50% reduction in opioid use may be the reflective of SCS's ability to reduce opioid reliance in chronic pain patients.
-
Complex regional pain syndrome (CRPS) is characterized by continued pain disproportional to the inciting event, sensory abnormalities, vasomotor and sudomotor disturbances, and motor and trophic changes. Inflammatory involvement has been demonstrated in past CRPS studies resulting in pain, swelling, and warmth. Currently, it is unknown whether spinal cord stimulation (SCS) has immunomodulatory properties. The aim of this study was to determine whether SCS has immunomodulatory properties in CRPS patients. ⋯ SCS in CRPS patients attenuates T-cell activation, improves peripheral tissue oxygenation and decreases anti-angiogenetic activity which results in diminished endothelial dysfunction and improved bloodflow. The possible immunomodulatory effects of SCS opens new therapeutic possibilities in diseases with the involvement of the immune system and vasomotor disturbances, and requires further research on these mechanisms of action.