Medicine.

Date:
[1919?]
Catalogue details

Licence: In copyright

Credit: Medicine. Source: Wellcome Collection.

    427/454 (page 391)
    The muscular tone should be maintained by tonics, electricity, and massage. Counter-irritation may be beneficial over the exit of the nerve in the peripheral type, which is usually amenable to treatment. EIGHTH OR AUDITORY NERVE. Describe the Nature of tins Nerve. It comprises two quite different sets of fibres, viz.:— cochlear for the function of hearing, and vestibular for •equilibration. The chief symptoms referable to this nerve are deafness, tinnitus, and vertigo. How man Deafness due to Otitis Media be differentiated from that due to Nerve or Labyrinth Affections ? Bv tuning-fork tests. In middle ear disease there is loss of aerial conduction, but bone-conduction is preserved. In the others (nerve deafness) bone-conduction is lost. Further, in labyrinth disease there is often tinnitus or vertigo, and loss of perception for high-pitched tones (Galton’s whistle). What is meant by Tinnitus, and. what is its significance. ? It is understood to mean ringing in the ears, though the noises may be buzzing, hissing, or whistling in character. They may be pulsating or continuous. Broadly, tinnitus points to irritation of some part of the auditory apparatus. The pulsating variety (synchronous with pulse) is found in neurasthenia, temporary Eustachian obstruction (coryza), or at times in intra-cranial aneurysm. The continuous type, when of low pitch, is caused by venous hypersemia (aggravated by recumbency) or anaemia (relieved by recumbency). When of high pitch it is due, as a rule, to labyrinthine stimulation from wax in external ear, Eustachian obstruction, or to disease of labyrinth. Certain drugs, e.g. quinine and salicylates may cause it.