CHAPTER XXXVIII.

"SCLEROSIS OF THE MIDDLE EAR" (RAREFACTION OF THE CAPSULE OF THE LABYRINTH).— ANKYLOSIS OF THE STAPES.

350. It had been noticed by even the earlier otologists that there is a certain type of progressive deafness which, while it resembles "dry catarrh" of the middle ear, differs from it sufficiently to be distinguishable clinically. On account of false pathologic ideas this disease has been termed sclerosis of the middle ear. Its true pathology has now been so completely demonstrated (by Politzer, Siebenman, and others) that an accurate differentiation is possible. Although an affection of the sound-conducting parts, it is really not a disease of the mucous membrane of the middle ear.

The disease begins usually between the fifteenth and twentieth years of life, less often later on, predominantly in females. It occurs in rather less than 5 per cent. of ear patients. It is always double-sided, and, as a rule, without much difference between the two ears. A hereditary tendency to ear disease is often found in the family. The hearing becomes gradually dulled, with very little other annoyance. No fulness, no stuffiness, no dizziness. Tinnitus is sometimes complained of to a moderate extent; it is neither constant nor steady. In the course of some years it becomes difficult to follow a conversation. In some the deafness does not proceed beyond considerable embarrassment in ordinary speech. In others it is steadily progressive, and after many years practically bars the patient from social intercourse.

These patients have no catarrhal history. During their younger years they are conspicuously free from nasal and pharyngeal disturbances, and their rare attacks of coryza

heal promptly. Later in life slight chronic changes may occur in the upper respiratory passages in unfavorable climates. The drumhead is normal at first. It may become slightly retracted, but not necessarily so. It often looks atrophic by reason of the special prominence of the neck of the hammer. The luster is normal. A pinkish hue due to congestion of the promontory is often noticeable through the translucent membrane, and is of inauspicious significance. The Eustachian tube is normal. Functional tests show reduced air-conduction, the result of fixation of the foot-plate of the stapes. Rinne's test soon becomes negative. The tuning-fork on the vertex is heard abnormally long. The main distinction between this form of disease and proliferative middle-ear disease is the pronounced deafness for the lowest tones of the scale when heard through the air. The range of audition is shortened by one to even three octaves at the lower end. In the course of years these tests become less decisive as the disease is likely to become complicated by involvement of the auditory nerve-ends. This is then indicated by shortening of the upper end of the auditory range on testing with the Galton whistle.

Sooner or later the disease ends in complete ankylosis of the stirrup-bony union of the foot-plate of the stapes to the walls of the niche in which the oval window is located. It is not yet certain whether this condition can be invariably recognized by means of Gelle's test (¶309). When the bony ankylosis is complete, the deafness usually ceases to increase. In some instances, however, the hearing continues to suffer even beyond this period, and the functional tests then indicate involvement of the nerve-ends in the labyrinth.

351. It was formerly supposed that this type of disease was due to fibrillary degeneration of the tympanic mucous membrane-hence the name, sclerosis. This supposition. was entirely wrong. The tympanic mucous membrane is normal in this disease. The real lesion is disseminated rarefaction of the bony wall of the labyrinth. Separate

small yellowish foci are found, especially in the neighborhood of the oval window. In these spots the compact bony substance is changed into the cancellated type. The rarefaction is indicated by the presence of lacunæ and of osteoclasts. Enlarged and newly formed vessels. render these foci abnormally vascular. Later on minute osteophytes form both on the tympanic and on the intralabyrinthine surfaces. This secondary proliferative process culminates in bony ankylosis of the foot-plate of the stirrup. It is doubtful whether the process can be called inflammatory. It is a return to the embryonic condition. of the bone from unknown causes. We know nothing of the etiology beyond the frequent family predisposition.

So-called sclerosis cannot be influenced therapeutically by any known means. Eustachian inflation is sometimes agreeable subjectively, but has no permanent influence and is even accused of being harmful in the end. The same may be said of massage. Excision of the ossicles or operative manipulation of the stapes only can be condemned on the basis of experience. No internal medication tried up to the present time-iodids, thyroid gland, phosphorus-has given any decisive results. It is generally believed, perhaps on doubtful evidence, that the disease is least likely to progress rapidly when the health is maintained at par.

352. Ankylosis of the stapes is a not infrequent lesion in proliferative middle-ear catarrh, as well as in socalled sclerosis, in which it is a constant terminal feature. In the former disease it is usually not a bony union. There may be true sclerosis of the deeper periosteal layer of the mucous membrane, causing fibrous rigidity, and this may be complicated by more or less calcification or even partial ossification. The lesion necessarily causes a high degree of deafness. It is indicated by the reversion of Rinne's test, by exaggerated bone-conduction and total deafness for aërial sound-waves of low frequency. When in Gelle's test increased air-pressure in the meatus

does not reduce the perception of aërial sound-waves, the diagnosis may be considered assured.

In most instances of stapes ankylosis due to proliferative catarrh of the middle ear the diagnosis of the catarrhal origin can be easily made. There are exceptional instances in which the functional tests indicate stapes rigidity at a very early period, while the other symptoms do not as yet point to any extensive proliferative changes in the middle ear. Such cases are sometimes difficult to distinguish from so-called sclerosis. The latter, however, is always bilateral, while in the former type of disease it is not uncommon to find one-sided instances with very little involvement of the other ear.

Ankylosis of the stapes may also be the consequence of a purulent otitis. If the latter has healed without leaving visible evidences in the membrana tympani, as sometimes happens in childhood, the diagnosis of the origin of the ankylosis may prove puzzling.

CHAPTER XXXIX.

SIMPLE OTITIS MEDIA (PURULENT OTITIS MEDIA WITHOUT PERFORATION).

353. Suppurative inflammation of the middle ear is distinguished from catarrh by the greater depth of the inflammatory infiltration, which may even extend into the bone, and by the nature of the exudation. The latter varies from clear serum to pure pus, but is not the more or less turbid mucus of catarrh. Purulent otitis has hitherto been identified with a clinical picture beginning with well-defined pain and leading to a perforation in the drumhead, with subsequent discharge through it. But while this is the predominating type of the disease, there are other forms which have as yet received less attention.

It has been shown that a purulent inflammation of the middle ear is found at autopsies in about four-fifths of all dead nurslings. There is in this case the same discrepancy between the frequency of the lesions found in the dead-room and the scantiness of clinical observation which has been noticed in diseases of the nasal accessory cavities. Kutscharianz, Kossel, Ponfick, and others have shown this remarkable liability to purulent otitis in infants during their last days of life, apparently independent of the cause of death. The exudate has been found to contain the familiar pyogenic microbes, streptococci, staphylococci, and pneumococci, as well as in some instances the influenza bacillus. While all evidence points to invasion through the Eustachian tube, which at this age is relatively wide and short, the nose and pharynx were found normal in many instances.

In nurslings dying shortly after birth Aschoff found frequently lanugo hairs and vernix caseosa in the drum