Volume 8 Issue 3 (pdf) - Andrew John Publishing Inc

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therapy options have been proposed.
These include steroids, vasodilators,
anticoagulants, plasma expanders,
vitamins, and hypobaric oxygen. 3,5,8
Current standard of care is a tapering
dose of systemic steroids, either oral or
intravenous. The treatment should be
started as soon after diagnosis in order
to obtain the best outcome. Prednisone
(1 mg/kg/day up to 60 mg max), as a
single dose for 10–14 days is currently
recommended by the American
Academy of Otolaryngology.
Other commonly used steroids include
methylprednisolone, prednisolone, and
dexamethasone, depending on
physician preference. Steroids were first
shown to have beneficial effects by
Wilson et al., who demonstrated that
patients receiving oral steroids
experienced a significantly greater return
of spontaneous hearing (61%), as
compared to those receiving placebo
(32%). This is believed to have benefit
due to research showing steroids blunt a
cellular inflammatory cascade that
occurs ISSNHL. 4,8,9
The initial use of transtympanic
injections of glucosteroids were
recommended as salvage therapy if
patients do not experience an increase in
hearing recovery within 10 days of the
initial treatment. However, there is
limited research to support dosing
regiments for salvage therapy. 10
prognosis
The prognosis of ISSNHL is dependent
on a variety of risk factors including
demographics, duration of hearing loss,
severity of hearing loss, speech
discrimination scores, age, presence of
vertigo, associated symptoms, and
audiogram characteristics. 11 Of all
demographic factors studied, advanced
age (>60 years in most studies) has been
universally correlated with decreased
rates of hearing recovery and lower
absolute threshold gains. 5 The greatest
spontaneous improvement in hearing
occurs during the first two weeks and
late recovery has been reported but is
rare. Treatment with corticosteroids
appears to offer the greatest recovery in
the first two weeks, with little benefit
after four to six weeks. 2
Changes to treatMent
options
Despite their widespread use, there is
little consensus on the effectiveness of
oral steroids in ISSNHL. High-dose
administration of systemic steroids can
raise risks of adverse effects, such as
avascular necrosis of the femur
head, immune suppression, endocrine
problems, osteoporosis, glucose
intolerance, or weight gain. 3 To avoid
these side effects, recent studies have
proposed transtympanic treatment be
used as the sole initial treatment for
ISSNHL, with studies showing this
protocol to be non-inferior to
conventional oral steroids. 4,12 However,
there are numerous downsides to this
approach; transtympanic steroids can
cause patient discomfort, are more
expensive, inconvenient to inject and
carry a risk of otomycosis. 3
Preliminary work has suggested that
administration of glucosteroids by
perfusion through a round window
catheter can deliver a higher
concentration of steroid to the inner ear
and improve hearing when compared to
tympanic membrane injection. This
delivery method can avoid the side
effects caused by systemic steroid use
and avoid tympanum perforation. 13,14
Currently, the Sunnybrook approach
involves an audiogram to confirm
hearing loss, followed by blood work to
rule out infectious processes if clinically
indicated. If the hearing loss is unilateral,
magnetic resonance imaging (MRI) is
ordered to rule out retrocochlear causes
such as an acoustic schwannoma. If
these investigations fail to a reveal cause
of hearing loss, then prednisone at
1 mg/kg/day for the first six days and
then tapering for eight days, for a 14-day
total course is prescribed. Patients are
also offered intratympanic dexamethasone
injections (1 cc of 10
mg/mL) for at least three daily injections
until hearing improvement plateaus. If
hearing improvement continues, then
the injections continue until audiologic
testing reveals no further improvement.
One major issue which has still not be
fully addressed is the window of
opportunity in which either oral or
intratympanic corticosteroid treatment
will continue to have any effect. Our
centre uses the 14–21 day windowpatients
presenting after that period are
not typically offered any treatment.
ConCLusion
Although controversial, the use of oral
steroids in the initial treatment of
ISSNHL has been considered by many
to be the gold standard of care. Current
research suggests that transtympanic
corticosteroid treatment increases
concentration in the cochlear fluids.
Therefore in the philosophy of
maximizing corticosteroid concentration
in the inner ear to minimize permanent
damage, we advocate a combined oral
and intratympanic corticosteroid
treatment paradigm in patients
diagnosed with SSNHL.
referenCes
1. National Institute of Deafness and Other
Communication Disorders (NIDCD). Sudden
deafness. 2003. http://www.nidcd.nih.gov/
health/hearing/pages/sudden.aspx. Accessed
October 26, 2012.
2. Stachler RJ, Chandrasekhar SS, Archer SM, et
al. Clinical practice guideline: sudden hearing
loss. Otolaryngol Head and Neck Surg
2012;146(3):S1–S35.
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