DISEASES OF THE EAR Diseases of the ear may affect the external, middle or internal ear. The commoner affections of the auricle are eczema, various tumours (simple and malignant), and serous and sebaceous cysts. Effusion of blood into the auricle is often due to injury, but may occur spontaneously, especially in insane persons. The chief dis eases of the external auditory canal are impacted cerumen (or wax), boils, strictures due to inflammatory affections, bony growths, malignant disease, caries and necrosis, and foreign bodies.
Diseases of the middle ear are suppurative and non-suppurative. The former is either acute or chronic, and is accompanied by per foration of the drum-head and discharge from the ear. The chief importance of these affections, in addition to pain, deafness, dis charge, etc., is that, if neglected, they may be followed by aural polypi, caries and necrosis of the bone, affections of the mastoid process, paralysis of the facial nerve, and the still more serious intracranial and vascular infective diseases of abscess in the brain, meningitis, subdural and extradural abscesses, septic thrombosis of the venous sinuses, and pyaemia. Acute suppurative disease of the middle ear is often due to the exanthemata, scarlatina, measles and smallpox, and to bathing and diving. It may also be caused by influenza, diphtheria and pulmonary tuberculosis.
Non-suppurative disease of the middle ear may be acute or chronic. In the acute form the inflammation is rarely accompanied by perforation. Chronic non-suppurative inflammations are moist, in which the symptoms are improved by inflation of the tympanum through the Eustachian tube, and dry (including sclerosis), which is intractable and not amenable to inflation. Diseases of the internal ear may be primary or secondary to an affection of the tympanum or to intracranial disease.
Injuries to any part of the ear may occur, among the commoner being injuries to the auricle, rupture of the drum head (from ex plosions, blows on the ear or the introduction of sharp bodies into the ear canal), and injuries from fractured skull.
The researches of Arthur Cheatle have shown that in 8o% of cases the mastoid process is composed very largely of air cells, that in the remaining 2o% it is dense or acellular as in infants, that mastoid cells may develop in regions other than the mastoid process, and that persistence or excessive development of certain small veins in the inner wall of the mastoid antrum may favour the spread of infection leading to intracranial complications. These anatomical features may determine the symptoms and line of treatment to be adopted when disease attacks the temporal bone, particularly in inflammatory disease of the middle ear.
Of late the attention of otologists has been more than ever con centrated on the labyrinth, and particularly on its vestibular com ponent. The internal ear or labyrinth comprises two essential structures, the cochlea which is to the ear what the retina is to the eye ; the vestibular apparatus which subserves two important functions: (a) static (saccule and utricle) which has to do with the maintenance of equilibrium, (b) kinetic (saccule, utricle and semicircular canals) for the recognition and analysis of motion.
In health certain tests give results indicating a normal con dition of the vestibular apparatus, e.g., the pointing tests, nystag mic movements of the eyes after rotation of the patient and the employment of the caloric and electrical tests. These reactions are modified or absent when the vestibule is diseased. Hence the aural surgeon can explore the labyrinth and its immediate neigh bourhood with minuteness. Consequently, certain types of vertigo, acute and chronic suppuration of the labyrinth with threatening symptoms of meningitis, and tumours of the auditory nerve, are often benefited by operation.
While little advance has occurred in the treatment of well known types of insidious and slowly progressive forms of chronic deafness, it is probable that future generations will suffer less from deafness. This will be due to prevention rather than cure, because it is recognized that the so-called "chronic middle-ear deafness" is primarily due to infection passing from the nasopharynx by way of the Eustachian tubes into the middle ear cleft and its adnexa. Prophylactic measures in school clinics, child welfare centres, etc., will go far towards the preservation of hearing and in the preven tion of complications apt to result from neglected acute and chronic suppuration of the middle-ear cleft, e.g., meningitis, abscess of the brain and certain types of septicaemia. In the diag nosis and treatment of the latter conditions, valuable assistance is derived from examination of the cerebrospinal fluid obtained by "lumbar puncture." Finally, A. R. Friel has demonstrated the value of zinc ioniza tion in chronic suppuration where sepsis is confined to the tym panum and does not involve the "attic" nor the antrum, and the perforation in the tympanic membrane is large enough to admit of the middle ear being filled with the ionizing fluid. Suppura tions intractable and of long duration, have been cured by one or two applications of this treatment.