Deafness is any impairment of normal hearing and is that symptom next
to pain and chronic discharge that causes the patient to visit the
doctor. If acute diseases of the ear, nose and throat could always be
successfully treated, there would be little trouble from the symptoms
of chronic pathology. It must be understood that catarrhal deafness is
a symptom of chronic otitis media and is, therefore, seldom of recent
origin.
=Etiology.=—Chronic otitis media is nearly always the result of the
extension of infection through the Eustachian tube and has come
from some acute or chronic nasopharyngeal infection. Chronic colds,
pharyngitis, tonsillitis, sinuitis, etc., resulting in acute or chronic
otitis media either with or without suppuration, constitutes the
beginning of catarrhal deafness.
=Symptoms.=—There is seldom any pain with this disease. Some cases have
an occasional acute attack with pain and other symptoms of acute otitis
media.
Deafness, varying with the progress of the pathologic changes, is
always present. The patient in the early stages will seldom admit
that he suffers from deafness and often he is honest because he may
not realize that he cannot hear normally until his otitis media has
progressed to the second or third stage. Most patients, in fact, do
not become alarmed about their hearing until it is too late to restore
normal hearing. For this reason, physicians should be on the lookout
for such conditions and should advise special treatment early.
The human species in its present environment, depends much less upon
the organs of special sensation than do the animals of the wild, and
they may therefore be very deficient in sight, hearing, smell, etc.
without actually realizing this loss.
In addition to deafness there are other symptoms such as occasional or
constant fullness or feeling of “stuffiness” as the patients express
it, due to partial or complete occlusion of the Eustachian tubes.
Tinnitus aurium or head noises is very common and often the most
annoying symptom. Autophony, or the loud sound of the patient’s voice
to himself, which often causes him to speak low and indistinctly,
occurs in the later stages. Presbyacusia, or the inability to adjust
the hearing apparatus to variations in pitch, commonly occurs in the
second stage and is evidenced by the fact that the patient does not
hear when more than one person is talking. Paracousis or perverted
phenomena of hearing, such as the better hearing of some persons in a
noisy environment, is a symptom of the third stage of otitis media and
often means an unfavorable prognosis, so far as marked improvement in
hearing is concerned.
=Pathologic Stages.=—For convenience of discussion we may consider
chronic otitis media in three stages.
=The First Stage.=—The active pathology is limited to the pharyngeal
portion of the Eustachian tube with some inflammation of the membranes
of the tympanic cavity. Closure of the tube followed by absorption of
the oxygen causes a decreased pressure in the tympanic cavity and thus
a retraction of the drum, decreased movement of the ossicles and a
general decrease in function of all tympanic structures. Deafness in
this stage may be very marked, especially if the Eustachian occlusion
has occurred from some nasopharyngeal acute inflammation. There may
be pain but there is always a characteristic “fullness” and sometimes
dizziness. Deafness in these cases varies with weather changes. If
proper treatment is had in time, the progress of the pathology can be
stopped and every case can be restored to normal hearing.
=The Second Stage.=—The active pathology has extended throughout the
Eustachian tube causing marked occlusion and some stenosis. There is
further inflammation of the tympanic structures with an increase in
the symptoms of the first stage. The drum membrane is less movable but
there is no fixation of the ossicles. Pressure upon the bulb of the
auroscope causes movement of that part of the drum to which the malleus
is attached. The drum is thicker, more retracted, and less movable
than in the first stage. Presbyacusia is common and often marked, but
there is no paracousis. More than 90% of these cases can be materially
improved and many can be made to hear normally if proper treatment is
given in due time.
=The Third Stage.=—The active pathology in the third stage consists of
an involvement of the entire mucous membrane lining the Eustachian tube
and tympanic cavity. These membranes are all chronically hypertrophied.
The Eustachian tube, however, is sometimes fairly well open, but the
ossicular attachments are more or less fixed by hypertrophied tissue
and adhesions and the drum is markedly retracted, thickened and usually
very immovable. The deafness is usually quite marked, head noises are
commonly present and often very annoying. Patients usually do not
notice a variation in their hearing from weather changes. Presbyacusia
is present in 80% of cases and their hearing for low tones is much
reduced.
Unless there is a complicating nerve affection these cases hear well
by telephone, which means that they can also use an electric hearing
instrument to advantage. These cases can never be restored to normal
hearing, but many of them (30% of my cases) can have some improvement
and in most cases I believe the progress of the pathology can be
stopped, and this is always well worth while because their hearing is
likely to be entirely lost if something is not done.
=Psychologic Stages.=—There are three rather distinct psychologic
stages in catarrhal deafness. The first, the period in which most
patients refuse absolutely to admit that they are deaf even to the
aurist upon whom they call for treatment. They insist that they hear
perfectly if people would only speak distinctly. This is partially
true, because up to the third stage of deafness the voice can be fairly
well heard if people would only articulate clearly. In the second
stage patients admit that they don’t hear well, but insist that they
are going to recover normal hearing and often resort to various kinds
of injurious treatment. In the third stage they give up all hope of
ever regaining their hearing, become morose, and avoid company. These
psychic stages do not always correspond with the pathologic stages
given above.
=Diagnosis.=—The external auditory meatus, drum membrane and ossicular
chain, constitute the apparatus whose function is that of conduction of
sound waves to the perception apparatus of the inner ear. The function
of the conduction apparatus varies inversely with the progress of
pathologic change in these structures. The perception apparatus, the
structures of the inner ear, are not necessarily affected by middle ear
pathology, but on the other hand, sounds transmitted by bone conduction
not only seem louder but they last longer because the “escape of the
excess” of sound thus transmitted is hindered by deficient conductive
mechanism. This explains why such persons hear well by telephone and
why the tuning fork, whose base is held to the mastoid (provided
there is no nerve affection) may be heard for a greater time than
normal. Likewise the prong of the vibrating tuning fork when held near
the concha is heard for a shorter time than normal, because of the
deficient function of the conduction mechanism.
Tuning forks are known by their number of vibrations per second, such
as 16, 32, 64, 128, etc. Three or more forks are required to make an
accurate measurement of the conduction and perception functions—a low
fork about a 32, for the low tones, 128 or a 512 for the medium tones
and a 2048 for the high tones.
A good set of forks should be selected and standardized, i. e., the
normal bone and air conduction of each fork determined by testing it
on a number of persons whose hearing is known to be normal. For the
general practitioner who cares only to get a general idea of the extent
of the pathology, one fork of medium pitch such as a 128 or 512 will be
sufficient.
To measure the function of hearing, the fork is set into maximum
vibration, its base held against the mastoid and the patient is asked
to state when he no longer hears it. This length of time in seconds is
recorded as “bone conduction.” The fork is then held near the concha
and the patient again states when he does not hear it. This length of
time in seconds is recorded as air conduction.