Electrical stimuli shape parametres optimization in electroanalgeisia

Abstract

The transcranial electrostimulation (TES) is a procedure based on the effect indused by electrical current when passing through the brain, through electrodes plased in the scalp. Several attempts were made to produce and maintain a state of general anesthesia, over more than 70 years, by administering different parameters of electrical currents, applied to the skin of the subject's head (i.e., transcranially and transcutaneously). However, due to the high intensity of current required to induce general anesthesia, these efforts were abandoned and superseded by attempts to produce analgesia, rather than general anesthesia, by application of electrical currents. The experiments were conducted on two lots of ten rats each (Wistar, males, 150-200 g each), all under general anesthesia, using Tiopental 50mg/kg. The carotid artery was catheterized and the catheter connected to a pressure measuring device, for the observation of the blood pressure deviations. The blood pressure was measured before TES, after pain stimulation, and after TES and painful stimulation. A rise in the blood pressure parameters would indicate an intense pain sensation. That is explained by the fact that at pain stimulation a “fight or run” reflex occurs, that is mainly accomplished by the sympathetic nervous system. The data obtained revealed a tendency of normalization in the blo.od pressure registered after pain stimulation when using rectangle shaped current. The parameters registered while using the triangle shaped current showed no notable changes before and after TES. The results indicate to the analgesic effect that can be obtained by TES with rectangle shaped currents. The triangle shaped currents showed no notable analgesic effect upon usage.