The term “nerve deafness” is generally used very carelessly to apply to
any chronic or non-suppurative process of the labyrinthine structures
other than those mentioned above, which cause impaired hearing.
Nerve deafness is not an uncommon disease. In my cases of deafness
there has been some involvement of the labyrinthine structures or
auditory nerve in 27% of the cases examined. I think the reason for
most authors putting the percentage of nerve deafness much lower than
this is because of inexact methods of diagnosis. The above percentage
is based upon the actual measurement of nerve force. See measurement of
nerve force under non-suppurative otitis media above.
A careful study of cases by the method of actual measurement of nerve
force, shows that there are two distinct forms of nerve deafness.
In one there is only a deficient function of the structures of the
labyrinth, due perhaps to some perverted physiologic function, and this
form we may call auditory nerve deficiency. The other form of nerve
deafness, due probably to an actual degeneration of the nerve or its
end organs in the labyrinth, may be properly known as auditory nerve
degeneration.
=Auditory Nerve Deficiency.=—A study of our case reports shows that in
64% of the cases in which the nerve force was 16-30 or higher (more
than half) favorable results were obtained, provided that there was
no complicating labyrinthine affection. These cases have been classed
as “nerve deficiency” and the pathology as functional. A favorable
prognosis (64%) may be offered.
Example of tuning fork findings:
Fork 32 64 128 512 2048 4096
B. C. 18 20 20 20 10
A. C. T 50 60 60 40 20
In addition to the tuning fork findings the voice and watch test will
be reduced to from one-tenth to two-thirds normal. The patient often
complains of itching meati and dry nares. There are usually no signs or
symptoms of labyrinthine affection.
=Treatment.=—The treatment consists of local treatment to the
nasopharynx, tubes and meati as described under the treatment of
chronic otitis media. Everything should be done to build up the
patient’s general health and improve the local nutrition. It is highly
essential to search the entire system for sources of focal and general
infection. Auto-intoxication from chronic gastro-intestinal disease
was found in 90% of our cases. Any treatment therefore that will
restore normal gastro-intestinal function is indicated. Recently we
have had some excellent results from colonic irrigation and the proper
adjustment of diet in such cases. Any source of focal infection must of
course receive proper attention.
The osteopathic corrective treatment consists largely of careful
attention to lesions of the splanchnic area because of the importance
of normal digestion, metabolism and elimination. This is certainly a
most important part of the treatment and should never be neglected.
Upper cervical and mandibular lesions have much to do with the local
nutrition to the ear structures and these must not be neglected. The
fact that we almost constantly find evidence of deficient nutrition
to the meati and drums in this disease together with lesions of the
mandible, suggests a local osteopathic cause.
=Auditory Nerve Degeneration.=—In those cases in which there is a
measurable deficiency of nerve function of less than half the normal we
have found that very few respond to treatment. (See table above.) The
cause has therefore been attributed to a structural pathology and the
condition called auditory degeneration.
Example Table:
Fork 32 64 128 512 2048 4096
B. C. 10 12 8 5 2
A. C. S 20 25 15 7 5
There is usually very marked impairment of hearing for voice and all
other sounds. The Ingersoll watch may be heard five or ten inches, but
usually not at all, and the whispered voice heard only a few inches or
not at all. There are nearly always signs and symptoms of labyrinthine
deafness and evidence of tone islands. The deafness in these cases is
usually progressive regardless of any treatment.
In this disease there is nearly always an associated affection of the
labyrinth as shown by the high forks. The fractions represented by the
high forks will agree in proportion provided there is no labyrinthine
involvement.
Our results in auditory nerve degeneration have been measurable
improvement in only 2% of the cases treated. The prognosis is therefore
very poor and I believe we should always tell our patients frankly
that there is almost no chance for improving their hearing in such
cases. The treatment is the same as that given for nerve deficiency and
because of the general good that may be had from treatment, that is,
the improvement of the general resistance, it is often well for the
patient to have such treatment to stop the progress of further special
sensory degeneration.
It should always be our purpose to treat the patient rather than to
treat some particular organ only and if this method is followed, our
general results will surely be much higher.