1. TOPIC
2
CAUSES OF HEARING
IMPAIRMENT

2. Outer and Middle Ear Disorders


Structural defects due to embryologic
malformations
Structural changes secondary to
infection or trauma

3. Outer Ear Disorders

Microtia and atresia

4. Microtia
“an abnormal smallness of the auricle”

5. Atresia
“the absence of
an opening of
the external
canal”

6. Outer Ear Disorders

Microtia and atresia

Impacted cerumen

Perforation of the tympanic membrane

7. Perforation of the TM
n
An example of the audiogram illustrating the flat,
mild, conductive hearing loss that can occur with a
perforated tympanic membrane

8. Outer Ear Disorders

Microtia and atresia

Impacted cerumen

Perforation of the tympanic membrane

Other

9. Middle Ear Disorders

Otitis Media



Most common cause
of transient
conductive hearing
loss in children
Inflamation of the
middle ear
Caused by
eustachian tube
failure

10. Otitis Media
n
Three examples of
the usual
characteristics of a
conductive hearing
loss arising from
otitis media

11. Ways to Classify Otitis Media


With or without effusion
Fluid type



Serous
Suppurative
Mucoid

12. Ways to Classify Otitis Media
 With or without effusion
 Fluid type
 Duration
 Acute
 Chronic
 Subacute
 Persistent
 Recurrent

13. Otitis Media Facts





76-95% of all kids will have one episode of OM by
age 6
Prevalence is highest during the first two years of life
50% of all kids with one episode before their first
birthday will have 6 or more bouts within two years
Most episodes occur in winter and spring
Risk factors






Cleft palate
Down syndrome
Native Americans
Urban poor
Day care
Secondhand smoke

14. Middle Ear Disorders


Otitis media
Otosclerosis

15. Otosclerosis
“a bone disorder that affects the stapes
and the bony labyrinth of the inner ear.
The disease process is characterized
by resorption of bone and new spongy
formation around the stapes and oval
window”

16. Otosclerosis

Facts:
 Hereditary
 Women are more likely
to develop the disorder
 Usually bilateral
 progressive

17. Middle Ear Disorders



Otitis media
Otosclerosis
Cholesteatoma

18. Cholesteatoma
“an epithelial pocket that forms on the
tympanic membrane. Once the pocket
forms, the normal shedding of
epithelium results in growth of the
tumor”

19. Middle Ear Disorders




Otitis media
Otosclerosis
Cholesteatoma
Other

Physical trauma

20. Physical Trauma of the Middle
Ear
Here’s an example of
an audiogram
resulting from
disarticulation of the
ossicular chain

21. Middle Ear Disorders




Otitis media
Otosclerosis
Cholesteatoma
Other



Physical trauma
Barotrauma
Middle ear tumors

Glomus tumor

22. Cochlear Disorders

Syndromes and inherited disorders


Syndromic disorders
Nonsyndromal disorders

23. Syndromes and Inherited Disorders Resulting in
Sensorineural Hearing Loss

24. Types of Nonsyndromic
Disorders





Dominant
Dominant progressive
Dominant progressive with adult onset
Recessive hereditary SNHL
X-linked

25. Cochlear Disorders


Syndromes and inherited disorders
Noise induced hearing loss

26. Noise Induced Hearing Loss
The degree of SNHL depends on

The intensity of the noise

The spectral composition of the noise

The duration of exposure

Individual susceptibility

27. OSHA Damage Risk Criteria

28. Noise Induced SNHL



Noise notch
Cummulative
Progressive

29. Cochlear Disorders




Syndromes and inherited disorders
Noise induced hearing loss
Other trauma
Infections

30. Infections

Congenital

Cytomegalovirus

HIV

Rubella

Syphilis

Toxoplasmosis

31. Infections

Acquired

Herpes Zooster Oticus (Chicken Pox)

Mumps

Syphilis

32. Cochlear Disorders





Syndromes and inherited disorders
Noise induced hearing loss
Other trauma
Infections
Ototoxicity

33. Ototoxicity
 Some antibiotics that are often ototoxic:

Amikacin

Dihydrostreptomycin

Garamycin

Gentamicin

Kanamycin

Neomycin

Netilmicin

Streptomycin

Tobramycin

Viomycin

34. Ototoxicity

Chemotherapy
 Carboplatin
 Cisplatin

Drugs that cause reversible hearing loss
 Quinine
 Salicylates (aspirin)
 Loop diuretics

Drugs that may be harmful during pregnancy
 Accutane
 Dilantin
 Quinine
 Thalidomide

35. Cochlear Disorders






Syndromes and inherited disorders
Noise induced hearing loss
Other trauma
Infections
Ototoxicity
Meniere’s Disease

36. Meniere’s Disease

Symptoms



Tinnitus
Vertigo
Unilateral
sensorineural
hearing loss

37. Cochlear Disorders







Syndromes and inherited disorders
Noise induced hearing loss
Other trauma
Infections
Ototoxicity
Meniere’s Disease
Presbycusis

38. Presbycusis

39. Central Auditory Disorders



VIII Nerve tumors
Other diseases of the VIII Nerve
Neural disorders



Brain Stem disorders




Cochlear neuritis
Diabetes mellitus
Infarcts
Gliomas
Multiple sclerosis
Temporal Lobe disorders