Neuromodulation : journal of the International Neuromodulation Society
-
Neural stimulation may provide analgesia for a variety of painful conditions. Activation of primary sensory neurons, which underlies pain relief by spinal cord stimulation, also may be achieved by stimulation at the level of the dorsal root ganglion (DRG). The DRG also is a site of pain pathogenesis, particularly in neuropathic pain. We therefore examined the hypothesis that field stimulation of the DRG directly suppresses excitability of sensory neurons. ⋯ Our findings indicate that direct excitation of the DRG by electrical fields reduces neuronal excitability and may provide a new analgesic approach.
-
Electrical stimulation has been used for many years for the treatment of pain. Present-day research demonstrates that stimulation targets and parameters impact the induction of specific pain-modulating mechanisms. New targets are increasingly being investigated clinically, but the scientific rationale for a particular target is often not well established. This present study compares the behavioral effects of targeting peripheral axons by electrode placement in the subcutaneous space vs. electrode placement on the surface of the skin in a rodent model. ⋯ The results presented show that TENS and SQS have different effects that could point to unique biologic mechanisms underlying the analgesic effect of each therapy. Furthermore, this study is the first to demonstrate in an animal model that SQS attenuates neuropathic and inflammatory-induced pain behaviors.
-
The conformational state of voltage-gated sodium channels is an important determinant for the efficacy of both local anesthesia and electrical neuromodulation techniques. This study investigated the role of subthreshold preconditioning ramp currents on axonal nerve excitability parameters in the presence of sodium channel blockers in myelinated A and unmyelinated C fibers. ⋯ Slow preconditioning ramp stimuli inactivate sodium currents. In the presence of sodium channel blockers, stronger ramp stimuli cause an increase in threshold, which is larger than that caused by the sodium channel blocker alone. Therefore, we conclude that small depolarizing ramp currents could be used to increase excitability threshold in the presence of low concentrations of local anesthetics. These additive effects might represent a target to address with peripheral nerve stimulation in order to suppress afferent pain signaling.
-
Editorial Historical Article
Progress in the technology of neuromodulation: the emperor's new clothes?