The reactions of experimental animals and of human beings to stimulation with the galvanic current have been investigated since early in the nineteenth century. Not only the reactions of normal subjects, but the reactions of animals and human beings with all types of experimentally produced and spontaneous lesions have been the subject of numerous investigations. Experiments on the latter group were carried out in an attempt to establish galvanic stimulation as a clinical procedure which might replace, or at least serve as an adjunct to, performance of the caloric and the rotation test for vestibular function.
Nystagmus, postural reactions, such as turning and rotation of the head, subjective vertigo and a tendency to fall have all been observed as a result of galvanic stimulation of the ears. The nystagmus has received more attention than the other reactions, because of an attempt of the investigators to correlate the galvanic reaction with
BUCHANAN AR, LADD LD. THE GALVANIC REACTION IN GUINEA PIGSI. THE NORMAL GALVANIC REACTION. Arch Otolaryngol. 1939;29(1):124–135. doi:10.1001/archotol.1939.00650050132013