In 1892, Ewald found that an abnormal atony developed in all the striated muscles of the body after removal of the labyrinths. Several explanations have been offered for the production of this labyrinthinertonus. All agree that it must be due to afferent impulses initiated in the vestibular nerve end-organs, the maculae acusticae and the cristae ampullares. Movement of the endolymph at these nerve terminations can conceivably produce these nerve currents.
Nerve fibers can be stimulated only at regular intervals. The period of stimulation is immediately followed by a refractory phase (from 0.002 to 0.003 of a second), in which the nerve cannot be stimulated. A stimulant must, therefore, be intermittent.
It is difficult to conceive of the mere position of the labyrinths in relation to gravitation as being sufficient to account for labyrinthine tonus. Whatever contribution to the afferent impulses from this source must come from the macular
HUBBY LM. LABYRINTHINE TONUS AND VARIATIONS IN INTRACRANIAL PRESSURE. Arch Otolaryngol. 1926;3(5):429–432. doi:10.1001/archotol.1926.00580010459003
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