Electrical Stimulation of Accessory Spinal Nerve in Cortical Activation and Autonomic Response in Healthy Subjects

This randomized, crossover sham controlled trial with sham intended to study the effect of electrical stimulation on peripheral nerve (spinal accessory nerve) with acupuncture needle in healthy subjects aims to access the effect o electrical stimulation of accessory spinal nerve in cortical activation, muscular perfusion and autonomic response in healthy subjects. Participants will be assessed through measure changes in cortical activation, local muscular peripheral perfusion and autonomic responses before and after intervention and intervention-sham, and crossed after a period of wash-out. The design aims to contribute to assessment of one electroacupuncture\'s techniques by measuring some of the physiological effects caused by peripheral stimulation.