A Human Experimental Model for Neuropathic Pain Using Combined Application of Capsaicin and Local Anesthetics

Main of the present study was to develop a model of concomitant C-fibre block and sensitization eliciting spontaneous pain as well applying topical capsaicin and local anesthetics (LA) to examine the sensory alterations after combined C-fiber block and sensitization in both different application orders (sensitization of blocked C-fibers and block of sensitized C-fibers), compared to each of both mechanisms alone. Thereby, we expect stronger sensory changes during the combined substance application than during the monoapplication. We expect also contralateral sensory alterations mirroring the changes on the intervention site after the combined capsaicin and LA application, being stronger than after sensitization alone absent after C-fiber block alone.