Electric stimulation on nystagmus and head deviation in hemilabyrinthectomized guinea pigs

It is known tha electric stimulation through the post-auricular electrodes affects the nystagmus and head deviation induced in the hemilabyrinthectomized animals. The purpose of this study is to evaluate the dffect of electric stimulation on the vestibular compensation. Pharmacological labyrinthectomy was performed by injecting chloroform into the right middle ear under light ether anesthesia. The guinea pig were divided into four groups : the control group, which was not electrically stimulated after labyrinthectomy, group 0.6mA square wave, group 0.3mA square wave and group 0.6mA plise wave. Electric stimulation, which started one hour after labyrinthectomy, was given through both retroauricular electrodes in the animals. Nystagmus and head deviations were recorded and analyzed to assess the degree of the disturbed balances and the compensatory process. Recording was done at 1, 2, 3, 4, 5, 8, 12, 18 and 24 hours after labyrinthectomy. Electrically stimulated groups, especially group 0.6mA square wave 0.6mA plise wave, showed faster compensation in the nystagmus and head-body deviation than the control group. Therefore, in this study, electric stimulation seemed to contribute favorably to the vestibular compensation in the animals which could not move spontaneously due to labyrinthectomy.