DESCRIPTION OF HEARING LOSS, TYPES PATHOPHYSIOLOGY EXAMINATION MANAGEMENT

1. HEARING LOSS
GEMMA S. MKUMBO
MD5
T/UDOM/2012/02831

2. HEARING LOSS
DEFINITION.
A person is said to have hearing loss when his
hearing is elevated to 20 decibel or above.
Severity of hearing loss:
• 0---20 db Normal hearing.
• 20---40 db Moderate hearing loss
• 40---60 db Moderately severe hearing
loss.
• 60---80 db Severe hearing loss.
• 80---100 db Profound hearing loss.

3. TYPES OF HEARING LOSS
• Conductive
hearing loss
• Sensorineural
hearing loss
• Mixed
hearing loss

5. SENSORINEURAL HL
• SNHR is normally permanent and
is caused by damage to the inner
ear or auditory nerve

6. CAUSES OF SENSORINEURAL
HL
• Congenital causes: (genetic & non genetic)
 Genetic:
About 50% are genetic. Intermarried among
close relatives increases the chance of sensorinueral
HL.
1. Pendreds disease:
 Non endemic goitre
 Sensirineural deafness at birth
1. Michels aplasia
 Total or near total aplasia of the inner ear
3 Waadenburgs syndrome
 Iris heterochromia
 Congenital deafness
 Hypertelorism

7. CONGENITAL NON GENETIC
SNHL
• Rubella syndrome:
Congenital deafness
Congenital cataracts
Congenital heart disease
Mental retardetion
• Kernicterous:
Rh incompactibility is a common cause
• Endemic cretinism

9. • Delayed genetic SNHL.
These conditions are genetically
predetermined but phenotypic
expression occurs later in life.
a.Familial progressive SNHL
b.Alports disease:
i.Progressive renal
insufficiency
ii. Progressive SNHL
iii.Catarct formation

10. ACQUIRED SNHL CT.
• Infections:
i.Mumps.
ii.Measles
iii.Ramsay Hunts syndrome:
(herpes zoster oticus)
iv.Bacterial meningetis.
v.Congenital syphilis.
• Trauma—Head injury (fractures of the
petrous bone)

11. ACQUIRED SNHL Ct.
• Tumours;
Cerebello pontine angle tumours.
i Acoustic neuroma
ii Meningioma etc
• Ototoxicity;
i Aminogycosides
ii rapid action diuretics
iii Quinine
iv Cytotoxic drugs
• Noise deafness
• Aging (presbyacusis)

13. EXAMINATION OF THE EAR AND
CLINICAL AUDITORY TESTING
• Like any other clinical examination,
auditory testing consists of history taking,
inspection and function tests

14. HISTORY
• Information about the onset, time course,
associated symptoms, and recent
activities may be helpful.
• Past medical history may reveal risk
factors for hearing loss.
– previous otologic surgery,
– ototoxic drug use, and
– previous or concurrent viral or upper
respiratory tract infection

15.  Any history of
trauma,
straining,
diving,
flying, and intense noise exposure should
be noted.
Family history

16.  Past medical history of other diseases
associated with sudden hearing loss
should also be obtained such as
 diabetes,
autoimmune disorders,
malignancies,
neurologic conditions (multiple sclerosis),
and hypercoagulable states.

17. PHYISICAL EXAM
• A complete head and neck exam should
be performed on all patients with sudden
hearing loss ,with special attention to the
otologic and neurologic examination

18. • Any processes such as
middle ear effusions,
infections,
 cholesteatoma, and
cerumen impaction,
should be excluded

19. • Office evaluation of hearing can be done
by softly whisperingsimple words or
numbers in each ear and asking the
patient torepeat them aloud
• The Weber and Rinnetests should be
performed using a 512-Hz tuning fork

20. WEBER TEST
• The Weber test
 is conducted by ringing a 512-Hz tuning fork,
placing it firmly on the middle of the forehead,
and asking the patient where the tones are
heard best: left, right, or center.
 If the hearing is symmetric, the tone is
centered.

22. THE RINNE TEST
is performed by comparing air
conduction to bone conduction on
each side.

24. SCHWANBACH TEST:
This test compares the duration of hearing
by bone condition of the patient to that of the
Examiner (Assuming he/she has a normal
hearing). A sounded tuning for is first
placed at the mastoid of a patient with
hearing loss and when he can no longer
hear the sound it is placed at the
examiner’s mastoid and using a stopwatch,
notes the numer of seconds the tone is
audile after the pt stops hearing it.

25. DIAGNOSTIC WORKUP

26. 1. AUDIOMETRY
Auditory responses
An audiogram (pure tone, speech,
tympanometry,) should be performed on all
patients with sudden hearing loss.
The audiogram is the foundation of the diagnosis
and provides prognostic information.
 Serial testing provides documentation of the
progression or resolution of the hearing loss and
response to treatment.

27. • In sensorineural hearing loss,
the sensitivity tosounds delivered as
bone-conducted stimuli and the sensitivity
to sounds delivered as air-conducted
stimuli are equal in theaffected ear, but
both are reduced (i.e., the threshold is
elevated).

29. • In conductive hearing loss,
 the bone conduction is normal, butthe air-
conducted thresholds are worse (elevated)
in the affectedear.

30. 2. IMAGING STUDIES
MRI
 All patients with unilateral SNHL greater than
20dB difference from unaffected side not
explained by history
 Unilateral persistent tinnitus not explained by
history
 Persistent vertigo

31.  Unilateral sudden SNHL, regardless of response
to steroids
is warranted to rule out a "retrocochlear"
abnormality (e.g.,neoplasm, stroke, or
demyelination
• In patients who cannothave brain MRI,
alternatives include CT-scanning,
• less sensitive than MRI for the detection of
retrocochlearabnormalities

32. 3. LAB. STUDIES
• Laboratory studies should be directed by the
history and physical examination findings.
1.Fluorescent treponemal antibody-absorption
(FTA-Abs)
for syphilis
2.Antinuclear antibodies (ANA), rheumatoid
factor, and erythrocyte sedimentation rate
(ESR)
 for autoimmune diseases

33. Lab cont……
3. aPTT, and clotting time
for coagulopathy
4.CBC and differential
for infection
5.Thyroid-stimulating hormone (TSH)
for thyroid disease
6.Fasting blood glucose
for diabetes mellitus
7.Cholesterol and triglycerides for hyperlipidemia

34. OTHER TESTS
Auditory brainstem response testing
and otoacoustic emissions (OAE) tests
• may provide additional information
regarding the functional integrity of the
auditory system.

35. MANAGEMENT OF HL
• SENSORINEURAL HL.
This form of HL is generally
not correctable. the use of
hearing aid devices can e used
A cochlear implant is an
electronic device currently been
used to correct perceptive hearing
loss.

36. REHABILITATION OF A
PATIENT WITH HEARING
LOSS/ DEAFNESS
• Rehabilitation helps a person with hearing
loss to cope with demands of his social
environment.
• Types of rehabilitation:
i Lip reading
Ii sign language
Iii Hearing aid machine
1V Cochlear implant

37. REHABILITATION OF A
CHILD WITH HEARING
LOSS/DEAFNESS
• Parent guidance.
To be educated on their child’s deafness.
Severity of the condition
Correctability of the condition
If it is hereditary, chances of having other
deaf children.

38. Instruction of how to talk to the child (Face
to face) To enable the child develop lip
reading
Child to be placed in a normal nursery
school at the age of three
to enable the him/her acquire proper
social maturity.

39. REHABILITATION OF THE
DEAF CHILD CT.
• Amplification:
Hearing aid machine should be used early
in life to enable thechild acquire speech.
• Education:
To be conducted in special classes with in
the same school for normal children

40. • Organization
The doctor,the speech therapist,the social
worker,thepsychologistand the teacher for
the deaf should work closely together in
rehabilitation of the child

41. END
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