Opening up of the internal meatus. This may be accompanied by a gush of cerebro-spinal fluid. There is nothing to be done except to try and keep the part as clean as possible and see that there is free drainage. Undoubtedly, as a result of this mishap, death has afterwards occurred in consequence of septic meningitis.
Injury to the internal carotid or bulb of the jugular vein. These are possibilities which, however, should not occur if ordinary care is taken.
Prognosis. The prognosis of labyrinthine suppuration is always grave, owing to the frequency of intracranial complications.
The most favourable cases are those in which the disease is localized and is of chronic duration. The most unfavourable are those in which acute suppurative labyrinthitis is accompanied by extensive bone disease.
According to statistics, the mortality is about 50% in cases not operated upon. As a result of operation, this has been reduced to less than 20%, and in the majority of these cases the ultimate fatal result cannot be put down to the operation itself. The patient is frequently seen too late, that is, after intracranial complications have already occurred. There is no doubt that the death-rate will diminish proportionately according as the necessity of operating early becomes more and more recognized.
With regard to hearing, extensive operations upon the labyrinth lead to complete deafness; nor, indeed, can recovery of hearing be expected except in those cases in which the disease and operations have been limited to the semicircular canals and to the posterior portion of the vestibule, and even then recovery of hearing is exceptional.
CHAPTER VIII
OPERATIONS FOR EXTRA-DURAL ABSCESS AND MENINGITIS
OF OTITIC ORIGIN
ON INTRACRANIAL COMPLICATIONS IN GENERAL
As the intracranial complications of otitic origin are due to direct extension of the pyogenic infection through the temporal bone to the cranial cavity, it follows that they will depend on the extent of the disease within the temporal bone, the direction in which it has spread, and the virulence of the infection. For this reason, also, the site of the intracranial lesion is always in close relationship with the area of the diseased bone. Thus, if the infection spreads upwards through the attic and tegmen tympani, it may lead to extra-dural abscess or to meningitis of the middle fossa, or to a temporo-sphenoidal abscess. Similarly, disease of the mastoid cells posteriorly may give rise to a perisinuous abscess, to meningitis of the outer surface of the posterior fossa, to lateral sinus thrombosis, or to a cerebellar abscess situated superficially and involving the outer portion of its lateral lobe just behind the lateral sinus; or caries of the floor of the tympanic cavity may give rise to thrombosis of the jugular bulb; or internal-ear suppuration to an extra-dural abscess occupying the posterior surface of the petrous bone, to meningitis of the posterior fossa, or to an abscess of the cerebellum deeply placed in its anterior inferior angle.