A system of clinical medicine, dealing with the diagnosis, prognosis, and treatment of disease / 2nd edition.
- Thomas Dixon Savill
- Date:
- 1909
Licence: In copyright
Credit: A system of clinical medicine, dealing with the diagnosis, prognosis, and treatment of disease / 2nd edition. Source: Wellcome Collection.
Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.
945/1012 (page 907)
![§617] the frequency with which the lower half of the face is affected in cases of hemiplegia. The facial fibres cross to the opposite side in the upper part of the pons, and appear on the surface at the lower edge of the pons. The nerve then accompanies the eighth (auditory) nerve to the internal auditory meatus. At the lower end of the internal auditory meatus the facial nerve presents a swelling (the geniculate ganglion), which gives off three important branches. It then enters the aque- ductus Fallopii, which curves forward over the foramen ovale on the inner wall of the tympanum, then passes downwards and out through the styloid foramen, and while traversing the parotid gland breaks into its two main terminal divisions, the temporo-facial to the muscles of the upper half of the face, the cervico-facial to those of the lower half, the platysma, the mylo-hyoid, and the posterior belly of the digastric. The first and clinically most important branch of the facial is the great petrosal (or Vidian) nerve, which joins the geniculate ganglion to Meckel’s ganglion. Meckel’s or the spheno - palatine ganglion is connected above with the second division of the fifth, and the lower branches coming off from it supply the palate (Fig. 168). It was formerly thought that these were motor branches originating from the facial, but clinical research shows that the great petrosal nerve is really sensory, and contains taste fibres derived from the second division of the fifth, which join the geniculate ganglion, pass along the facial trunk, and leave the facial trunk as the chorda tympani nerve. It was Hughlings Jackson who first declared he had never seen undoubted paralysis of the palate in association with lesions limited to the facial nerve, that the palate is to a certain extent asymmetrical in most people, and that this fact had not hitherto been sufficiently allowed for. It is, moreover, a clinical fact which Gowers has insisted upon, that loss of taste is only associated with lesions of the facial nerve situated at some point between the geniculate ganglion and the styloid foramen. Lesions of the facial nerve behind the latter point do not give rise to loss of taste. Clinically, it is of great importance to remember that the Fallopian aqueduct is pierced by three structures, and through these holes inflammation may spread to the facial nerve. The first con- tains a small nerve twig from the facial nerve to the stapedius muscle. The second contains an arterial twig from the tympanum for the nutriment of the structures in the aqueduct. The third contains the chorda tympani nerve which comes off from the facial f inch above the stylo-mastoid foramen, and passes for- wards between the handle of the malleus and the stapes, turns downwards, and after giving a vaso-constrictor branch to the submaxillary ganglion, terminates in the tongue, which it supplies with taste fibres at the tip and along the anterior two-thirds of the margin. In the Clinical Investigation of cases of facial paralysis, as in other disorders of the nervous system, the first step is to discover the position of the lesion and then its nature. This is done by investigating first, the muscles that are affected ; secondly, the condition of the hearing ; thirdly, the condition of the taste ; and fourthly, the electrical reactions. The Sijm'ptoms of complete paralysis of the facial nerve (Bell’s paralysis) are (i.) an obvious one-sided alteration of the face which is pulled up away from the paralysed side by the unaffected muscles, the forehead and cheek of the paralysed side being smooth and ex- pressionless. (ii.) The patient cannot shut his eyes, or in slight cases lie cannot keep them shut when we try to forcibly open them, (iii.) The corner of the mouth is drawn up when he attempts to screw up the eyes, he cannot smile or show his teeth. lie cannot whistle, and the food collects between the cheek and teeth, (iv). The taste and (v.) the hear- ing may be affected in certain cases (see below). Paresis of the palate](https://iiif.wellcomecollection.org/image/b24907455_0945.jp2/full/800%2C/0/default.jpg)
