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OTOSCLEROSIS                                      375

through the membrane, usually behind the handle of the malleus. This is due
to hyperaemia of the promontory and affords good evidence that the oto-
sclerotic process is in an active phase. The Eustachian tube is usually patent.
On the other hand, the presence of scars in, or opacity or retraction of, the
drumhead in association with Eustachian obstruction by no means negatives
the diagnosis of otosclerosis. Otosclerosis may be complicated by middle ear

Tuning fork tests show a negative Rinne's test and Weber's test is lateral-
ized to the more affected ear. Audiometry confirms the presence of a con-
ductive deafness with, usually, normal inner ear function. Sometimes there
may be a diminution of inner ear function, earlier than can be accounted
for by presbyacusis.

There are rare cases of otosclerosis in which the focus of spongification
does not affect the region of the oval window but involves the capsule of
the cochlea at a separate spot. In such cases there is no paracusis, and tuning-
fork tests give the results normally obtained in a case of sensorineural
deafness. It has been suggested that if a young or middle-aged patient suffers
from nerve deafness for which no other cause can be found, and if in her
or his family there are individuals suffering from typical otosclerosis, the
case should be regarded as one of spongification of the labyrinth capsule
(atypical otosclerosis).

PROGNOSIS. Patients should be assured that the progress of the disease
is usually very slow, that no brain disease is present, that the condition is
not dangerous to life and does not result in absolute deafness. Pregnancy,
illness and accident may cause a rapid increase of the deafness and tinnitus.
If the affection comes on early in life, the prognosis is extremely poor from
the hearing point of view.

TREATMENT. Patients with otosclerosis hear well with a hearing aid, but
as treatment is usually sought in early adult life or in middle age, surgical
treatment is usually preferred.

Since the widespread practice in the past 25 years of the operation of
mobilization of the stapes, many different techniques have been described.
In these operations, carried out through an aural speculum under the oper-
ating microscope, the skin of the posterior bony meatal wall is incised to
form a U-shaped flap, which is elevated together with the annulus tym-
panicus, and the posterior half of the tympanic membrane is folded forwards,
thereby exposing the tympanic cavity. A direct approach can then be made
to the site of the disease (Fig. 197). Mobilization of the stapes was effected
by applying pressure to its neck in the direction of the stapedius tendon.
Successful mobilization was achieved in about one-third of cases, but re-
fixation of the stapes was almost invariable.

Satisfactory improvement in hearing in more than 80 per cent of cases,
with closure of the air-bone gap in the great majority, has resulted from
various techniques based on complete removal of the stapes, i.e. staped-
ectomy. The stapes is replaced by a prosthesis, e.g. of vein graft and poly-
thene tube, fat and wire, or a Teflon piston inserted into a small opening
in the footplate (Fig. 198). The stay in hospital is short.

RESULTS. In about 80 per cent of cases hearing approaching normal can
be achieved, but this will be limited by any inner ear loss. This high success
rate has to be balanced against a possible operative deterioration of hearing,