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HEARING LOSS: CAUSES AND TREATMENT

Hearing loss can be caused by many different
causes, some of which can be successfully treated
with medicine or surgery, depending on the disease
process.

THREE TYPES OF HEARING LOSS
Conductive hearing loss – when hearing loss is
due to problems with the ear canal, ear drum, or
middle ear and its little bones (the malleus,
incus, and stapes).
Sensorineural hearing loss (SNHL) – when
hearing loss is due to problems of the inner ear,
also known as nerve-related hearing loss.
Mixed hearing loss – refers to a combination of
conductive and sensorineural hearing loss. This
means that there may be damage in the outer or
middle ear and in the inner ear (cochlea) or
auditory nerve.
Conductive Hearing Loss
Causes:
Malformation of outer ear, ear canal, or middle
ear structures
Fluid in the middle ear from colds
Ear infection (otitis media – an infection of the
middle ear in which an accumulation of fluid may
interfere with the movement of the eardrum and
ossicles
Allergies
Poor Eustachian tube function
Perforated eardrum
Benign tumors
Impacted earwax
Infection in the ear canal
Foreign body in the ear
Otosclerosis
Treatments of Conductive Hearing Loss:
Types of conductive hearing loss include congenital
absence of ear canal or failure of the ear canal to be
open at birth, congenital absence, malformation, or
dysfunction of the middle ear structures, all of which
may possibly be surgically corrected. If these are
not amenable to successful surgical correction, then
the hearing alternatively may be improved with
amplification with a bone conduction hearing aid, or
a surgically implanted, osseointegrated device (for
example, the Baha or Ponto System), or a
conventional hearing aid, depending on the status of
the hearing nerve.
Other causes of conductive hearing loss are:
infection; tumors; middle ear fluid from infection or
Eustachian tube dysfunction; foreign body; and
trauma (as in a skull fracture). Acute infections are
usually treated with antibiotic or antifungal
medications. Chronic ear infections, chronic middle
fluid, and tumors usually require surgery. If there is
no response to initial medical therapy, infectious
middle ear fluid is usually treated with antibiotics —
while chronic non-infectious middle ear fluid is
treated with surgery (or pressure equalizing tubes).
Conductive hearing loss from head trauma is
frequently amenable to surgical repair of the
damaged middle ear structures, performed after the
patient’s general medical status is stabilized
following acute traumatic injuries.
A genetic form of conductive hearing loss is
otosclerosis, in which there is bony fixation of the
stapes (the third little bone of hearing in the middle
ear), where sound can’t get to the middle ear.
Otosclerosis usually presents with hearing loss in
early adulthood. Otosclerosis can successfully be
managed with surgery to replace the immobile
stapes with a mobile stapes prosthesis or with a
hearing aid. Research suggests that the measles
virus may contribute to stapes fixation in those with
a genetic predisposition to otosclerosis. The
incidence of otosclerosis may be decreasing in
some communities due to measles vaccination.
Otosclerosis (a hereditary disorder in which a bony
growth forms around a small bone in the middle
ear, preventing it from vibrating when stimulated by
sound) usually causes a conductive hearing loss, a
hearing loss caused by a problem in the outer or
middle ear. Less frequently, otosclerosis may cause
a sensorineural hearing loss (damaged sensory
cells and/or nerve fibers of the inner ear), as well
as a conductive hearing loss.
Sensorineural Hearing Loss
Causes:
Exposure to loud noise
Head trauma
Virus or disease
Autoimmune inner ear disease
Hearing loss that runs in the family
Aging (presbycusis)
Malformation of the inner ear
Meniere’s Disease
Otosclerosis – a hereditary disorder in which a
bony growth forms around a small bone in the
middle ear, preventing it from vibrating when
stimulated by sound.
Tumors

Treatment of Sensorineural Hearing Loss:
Sensorineural hearing loss can result from
acoustic trauma (or exposure to excessively
loud noise), which may respond to medical
therapy with corticosteroids to reduce cochlea
hair cell swelling and inflammation to improve
healing of these injured inner ear structures.
Sensorineural hearing loss can occur from head
trauma or abrupt changes in air pressure such
as in airplane descent, which can cause inner
ear fluid compartment rupture or leakage, which
can be toxic to the inner ear. There has been
variable success with emergency surgery when
this happens.
Sudden sensorineural hearing loss , presumed to
be of viral origin, is an otologic emergency that is
medically treated with corticosteroids.
Bilateral progressive hearing loss over several
months, also diagnosed as autoimmune inner ear
disease, is managed medically with long-term
corticosteroids and sometimes with drug
therapy. Autoimmune inner ear disease is when
the body’s immune system misdirects its
defenses against the inner ear structures to
cause damage in this part of the body.
Fluctuating sensorineural hearing loss may be
from unknown cause or associated with
Meniere’s Disease. Symptoms of Meniere’s
disease are hearing loss, tinnitus (or ringing in
the ears), and vertigo. Meniere’s disease may be
treated medically with a low-sodium diet,
diuretics, and corticosteroids. If the vertigo is
not medically controlled, then various surgical
procedures are used to eliminate the vertigo.
Sensorineural hearing loss from tumors of the
balance nerve adjacent to the hearing nerve,
generally are not reversed with surgical removal
or irradiation of these benign tumors. If the
hearing loss is mild and the tumors are very
small, hearing may be saved in 50 percent of
those undergoing hearing preservation surgery
for tumor removal.
Sensorineural hearing loss from disease in the
central nervous system may respond to medical
management for the specific disease affecting
the nervous system. For example, hearing loss
secondary to multiple sclerosis may be reversed
with treatment for multiple sclerosis.
Irreversible sensorineural hearing loss , the most
common form of hearing loss, may be managed
with hearing aids. When hearing aids are not
enough, this type of hearing loss can be
surgically treated with cochlear implants .
Mixed Hearing Loss
Treatments for Mixed Hearing Loss
Audiologist Mark Ross, Ph.D., recommends taking
care of the conductive component first. There have
been times when the addition of the conductive
component made the person a better hearing aid
candidate, by flattening out the audiogram for
example, while the underlying sensorineural
component presented a high-frequency loss.
However, still the emphasis would be on treating
medically what can be treated. He says that,
generally, you would expect positive results.

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