Effects of Current Density on Nociceptor Activation Upon Electrical Stimulation in Humans.

摘要: Objectives Mechano-insensitive (“silent”) nociceptors contribute to neuropathic pain. Their activation causes an axon-reflex erythema, but their high electrical excitation thresholds complicate assessment, particularly in painful neuropathy. We therefore developed stimulation paradigms for brief nociceptor and explored sensitivity clinical trials. Method The local ethics committee approved the study protocol, 14 healthy subjects were enrolled. Electrical stimuli administered ventral forearm dorsum of foot via self-adhesive 3 × 10 mm electrodes a pair blunted 0.4-mm-diameter platinum/iridium pin electrodes. Pain determined activated at 1.5-fold pain threshold by 5 blocks delivering 10 pulses each randomized frequencies 20 50 100 Hz, respectively. Axon reflex erythema recorded. Results Increased dose-dependently increased (P < 0.0001). Pin electrode was more than adhesive (P < 0.04) feet. significantly smaller feet At both skin sites, evoked larger (P < 0.05). Conclusions Electrical current density using is sensitive method investigating “silent” nociceptors, which might preferably be applied conditions.