Transcript Sudden hearing loss

Sudden Idiopathic
Hearing Loss
Molly Simpson and Beth
Burlage
Definition - Distinction
needed
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Idiopathic Hearing Loss(ISSHL)- Perceptive
hearing loss, etiology remains unknown after
clinical, laboratory and imaging studies,
hearing loss occurred within 24 hours, hearing
loss is nonfluctuating, severity of the hearing
loss averages at least 30 dB HL for three
subsequent one octave steps in frequency,
blank otological history in an otherwise
healthy individual
Sudden Hearing Loss (SSHL) - a
sensorineural hearing loss of 30 dB over less
than three days affecting three contiguous
frequencies, symptom of a greater condition
Symptoms
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Unilateral (only 2% of cases experience
bilateral deafness)
Roaring tinnitus
Short- lived dysequilibrium/vertigo
Audiometry Examples
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Possible Slopes of HL
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Low Frequency
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Low through Mid-High Frequency
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High Frequency - downward sloping loss
has a worse prognosis than low and midfrequency loss
Causes
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The term “idiopathic” indicates an unknown
origin
Research suggests SSHL etiology as:
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Compromised Vascular Supply
Intracochlear Membrane Breaks, Perilymph Fistula
Neurologic lesions
Viral Infections
Traumatic insults
Autoimmune Inner Ear Disease
Enlarged Vestibular Acqueduct Syndrome
Syphillis
Diagnosis
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ISSHL can often be mistakenly diagnosed as
a middle ear disorder
Testing will reveal
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Normal Tympanometry; Abnormal Reflexes
Tuning fork tests will indicate a sensorineural loss
OAE/ABR abnormal
Audiometry will usually show a unilateral loss
CT Scan/MRI needed to rule out neuroma
Negative fistula test
Urinalysis, blood work
Treatment
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Depends on identification of lesion
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Vascular
 Hyperbaric oxygen therapy (HBOT) involves breathing
pure oxygen in a specially designed chamber and it is
sometimes used as a treatment to increase the supply of
oxygen to the ear and brain in an attempt to reduce the
severity of hearing loss
 Carbogen treatment: 95% oxygen and 5% carbon dioxide.
Carbogen inhalation therapy is given for about 10 minutes
each 6–8 hours over a three-day period by a respiratory
therapist. This treatment is thought to increase the
oxygen in the perilymph by dilating the cochlear artery
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These treatment routes may not be covered by insurances
Treatment, cont.
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Structural defects may require surgical
treatment
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Fistulas
Acoustic neuromas
Treatment, cont.
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If no site of lesion is found, aggressive steroid
treatment is usually prescribed
Prednisone: 1mg/kg per day for 2–4 weeks, rapidly
tapering the drug if there is a complete recovery of
hearing. If hearing does not recover, reduction of
medication is slowed.
The best outcome: when steroids are administered as
quickly as possible
Some may benefit from antivirals, diuretics, a lowsodium diet, a restriction in the use of stimulants,
(alcohol and tobacco) and avoidance of excessive
physical activity and noise exposure.
Treatment, cont.
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35-50% of people have hearing return to
normal levels
If the hearing does not return, hearing
aids, cochlear implants or assistive
listening devices may be prescribed
ASHA recommends a multi-memory,
digitally programmable hearing aid, or
with a volume wheel for flexibility.
Prevention
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Most studies find no seasonal,
geographic, ethnic, racial or sexual
predilection for SHL.
The right and left ears appear equally
vulnerable.
It affects about 4,000, usually between
40-60 years old
Our Role
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Test to rule out middle ear pathology
and confirm sensorineural lesion
Understand the emotional aspect to this
type of hearing loss and need for
counseling
Three step approach: administrative,
medical, rehabilitative
Clincial Example
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46-year-old female
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Sudden onset of unilateral tinnitus and
decreased hearing while at work
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Awoke in the morning to limited hearing
in left ear
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MRI indicated no structural anomalies
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Audiometry = Profound loss across all
frequencies tested
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Diagnosed as an idiopathic viral infection,
treated with steroids
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Currently, hearing has not improved
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Complains of inability to localize
Habit of answering the phone with poor ear
Discussed possibilities for ALD’s for phone
use and CROS hearing aids
Any other suggestions?
References
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Menner, A. (2003) A pocket guide to the ear. New York: Thieme.
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Vause, N. (2002) Idiopathic Sudden Sensorineural Hearing
Loss—On the Other Side of the Audiometer. Military Audiology
Short Course.
http://www.militaryaudiology.org/masc2002/07_ISSHL.html.
Retrieved April 15, 2008.
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Wynne, M., Diefendorf, A., Fritsch, M. (2001) Sudden Hearing
Loss. The ASHA Leader Online,
http://www.asha.org/about/publications/leader-online/archives/2001/.
Retrieved April 20, 2008.
Autoimmune Disorders
Molly Simpson and Beth
Burlage
Autoimmune disorder
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“An autoimmune disorder is a condition
that occurs when the immune system
mistakenly attacks and destroys healthy
body tissue” Medline Plus
Women are more commonly affected
than men
Autoimmune disorders can cause
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Destruction of different body tissues
Changes in organ function
Abnormal growth of an organ
Autoimmune Inner Ear Disease
(AIED)
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Syndrome with progressive, fluctuating
bilateral sensorineural hearing loss,
dizziness and sometimes tinnitus which
progresses over weeks to months
First proposed in 1979
Can be confused with Meniere’s
Disease
Responsible for a very small number of
hearing impairment cases (< 1%)
Most common in middle-aged women
Causes of AIED
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Caused by antibodies or immune cells that damage
the inner ear
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Bystander damage= inner ear damage causes cytokines to
be released which create further immune reactions after a
delay (fluctuating symptoms)
Cross- reactions*= antibodies or T-cells accidentally damage
the inner ear if the ear shares common antigens with a
harmful substance the body is already trying to fight off
(COCH5B2)
Intolerance= the body may not know all of the antigens in the
inner ear. When they are released (after surgery, trauma or
infection), the body attacks them (partially immune privileged
locus)
Genetics= some people are genetically pre-disposed to
immune disorders
* This is the currently favored theory
Diagnosis of AIED
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Audiological Evaluation
Vestibular Testing
ABR (to rule out AN)
ECochG (to rule out Meniere’s)
Responsiveness to steroids
Blood tests for general autoimmune disorders
Blood tests for inner ear disorders
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Anti-cochlear antibodies (HSP70)
Lymphocyte transformation assay
Blood tests for diseases/problems that mimic AIED
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FTA (syphilis infection)
Lyme disease
Diabetes
Treatment of AIED
Corticosteroids (managed by a
Rheumatologist)
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Prolonged usage is shown to have serious
negative side effects Broughton, Meyerhoff and Cohen, 2004
Dosage is often tapered to the lowest one
that prevents fluctuations in hearing Broughton
et.al
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Benefit is not found in all patients and high
dosages may be needed occasionally as a
“booster”
Treatment continued…
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Cytotoxic Agents (chemotherapy-type
medications)
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Methotrexate
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Highly toxic and studies show limited benefit
Cochlear Implants
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For individuals who do not respond to
medical treatment and profound hearing
loss is permanent
Take home message…
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“AIED is one of the few reversible
causes of sensorineural hearing loss”
Gopen, Keithley and Harris, 2006
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Early diagnosis and treatment are
crucial to reversal or progression!
References
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Mathews, J., Kumar, B.N. (2003), Autoimmune sensorineural hearing
loss, Clinical Otolaryngology, 28:479-488.
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Broughton, S.S., Meyerhoff, W.E., Cohen, S.B. (2004), Immunemediated inner ear disease: 10-year experience, Seminars in Arthritis
and Rheumatism, 34:544-548
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Gopen, Q., Keithley, E.M., Harris, J.P. (2006), Mechanisms underlying
autoimmune inner ear disease, Drug Discovery Today: Disease
Mechanisms, 3(1):137-142.
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Vestibular Disorders Association
 http://www.vestibular.org/vestibular-disorders/specificdisorders/autoimmunity.php
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American Hearing Research Foundation
 http://www.americanhearing.org/disorders/autoimmune/autoimmune.html