Middle ear

1. Middle Ear Disorders
Lecture 13

2. Outline
 Anatomy – ME
 Development
 Changes due to Mass/Stiffness
 Disorders
 Otitis Media
 Mastoiditis
 Cholesteatoma
 Otosclerosis

4. Embryonic Development of ME
 1st month: formation of ossicles starts
 6 weeks: oval window formed
 3rd month: ossicles fully developed but still
cartilaginous tissue
 5-6 months: ossification of ossicles

5. Development of ME

6. Resonant Frequency of Ear

7. MASS vs STIFFNESS
 Mass –
 Changes in Mass occur with ME
 Stiffness
 Changes in Stiffness occur with ME

8. MASS vs STIFFNESS
 When you increase stiffness of ME, you
decrease the low frequencies on audio
 This results in a slight increase in the
resonant frequency of the ear

9. MASS vs STIFFNESS
 When you increase Mass of ME, you will see
a decrease the high frequencies
 This results in a slight lowering of the
resonant frequency of the ear

10. Otitis Media
 70% of children under age 3 have at least 1 episode
(Winskel, 2008)
 50% of children will have 1st infection before age
1(ASHA, 2004) and 9/10 before age 5.
 35 % of these will have recurring OM (ASHA, 2004)
 Most common cause of HL in children under age 3,
which occurs while developing language
 OM and language development
 OM and academic ability
 OM and literacy

11. Impact of OME
 NOT a relationship between OME and cognitive
function (Roberts et al, 1995)
 Presence of fluid/infection causes ____________ HL
 Fluid may take ___________________to resolve
 Hearing loss may continue to be present after
________________

12. Otitis Media
 Acute Otitis Media: fluid in the middle ear
with signs of infection (bulging eardrum, ear
pain, drainage, perforation)
 Otitis Media with effusion: fluid in the middle
ear without signs of infection (sometimes
called serous effusion)

13. OM Sequence
 Organisms access ME via Eustachian Tube
(ET)
 ET becomes swollen and blocked
 ME pressure drops (vacuum results)
 Infection spreads to mucous lining of ME
space
 Tympanic Membrane retracted

14. OM Sequence (cont.)
 Fluid accumulates in the ME space
 Bulging observed
 Fluid becomes infected
 Rupture of TM or Bleeding possible

15. From:http://www.rcsullivan.com
1. Serous Effusion (no
infection)
2. Acute OM –
Bulging TM
3. Resolving
OM

16. Untreated OM - Mastoiditis
 invasion of the fluid into mastoid bone

17. OME
 Symptoms
 Fever
 Ear Pain
 Hearing Loss
 Irritability
 Pulling on ear
 Poor sleep
 Drainage

18. Audiometric Results
 Degree of HL:
 Type:
 Tympanogram:
OAEs:
ABRs:
IWI:
Absolute latency of wave V
Absolute threshold of wave V

19. Interventions
(Pediatrician, ENT)
 Watchful Waiting
 Antibiotics
 PE Tubes
 Myringotomy
 Politzerization
 Valsalva maneuver

20. fromhttp://www.rcsullivan.com

21. Interventions
 Politzerization blowing air with a special
syringe into one nostril while blocking the
other, and at the same time swallowing.
 Force air into the ET and the ME
 “Ear-Popper”
 The Valsalva maneuver: forcibly blowing air
into the middle ear while holding the nose.
Should not be done if there is a cold and
nasal discharge.

22. Prevention of OM

23. Cholesteatoma
 Non malignant tumor in ME space
 Condition where skin has entered the ME space
 Small sac like tumor made up of proteins, fats and
tissue
 As it grows – damage the bones in the ME

24.  Most common cholesteatomas from OM

25. From: http://www.earsurgery.org/cholest
 Congenital cholesteatoma

26. Etiology/Symptoms
 Etiology: Perforations: skin enters ME
Retraction of TM
 Symptoms: HL, drainage with foul odor, ear
pressure, dizziness, facial weakness
 Left untreated - can spread to inner ear or
brain

27. Audiometric Results with Cholesteatoma
 Degree:
 Type:
 Tympanogram:
 Reflexes:
 OAE:
 ABR: IWI
 Lowest level of wave V
 Overall latencies of wave V

28. Intervention
 ENT: Mastoidectomy
needs frequent follow-up
keep ear dry
antibiotics: both oral and ear drops
CT-Scan/MR imaging: determines
extent
 Audiological: post-op results

29. Bell’s Palsy
 Incidence of 13-18 per 100,000
 Family tendency for onset
 Damage to the facial nerve
 Unilateral facial paralysis
 Etiology: from viral or bacterial infection,
tumor, swelling, injury

30. Facial Nerve – VII Cranial Nerve
 Innervates 7000 nerve
fibers
 Crosses the wall of the
middle ear space
 Carries impulses also to
tongue, saliva glands,
tear glands, stapes

31. Symptoms
 Twitching, weakness, tearing, numbness on
one side
 Changes in taste – Chorda tympani nerve-
branch of the facial nerve
 Not a disease
 Rarely causes HL alone
 Differentiate from acoustic
 neuroma

32. Intervention
 ENT: Steroids esp within week after onset
 Recovery in 4-6 weeks may take up to 4
months for full recovery
 Eye patch at night
 Keep eye from drying out
 Permanent Facial Nerve paralysis:
surgical interventions
PT- facial retraining

33. Audiometric Results with Bell’s Palsy
 Degree:
 Type:
 Tympanogram:
 Reflexes:
 OAE:
 ABR: IWI
 Lowest level of wave V
 Overall latencies of wave V

34. Otosclerosis
 Abnormal bone growth occurs in the middle
ear around the footplate of the stapes.
 prevents ossicular chain from moving
properly
 Footplate of stapes becomes “fixed” at the
oval window

35. Otosclerosis
 Progressive
 More common in adults, rare in children
 Higher prevalence in females: adolescence
through middle age (2:1)
 Genetic
 Hereditary: Accounts for 70 % of cases
 Autosomal Dominant
25% chance if one parent carrier
50% chance if both parents carriers

36. Symptoms
 Gradual HL: initial onset after puberty
Increased HL after pregnancies
 Tinnitus
 Dizziness
 Paracusis Willisi

37. Audiogram – Otosclerosis

38. Medical Interventions
 Sodium Fluoride Treatment – reduces bone
absorption and enhances calcium development of
bones
 Stapedectomy: removal of stapes and replacement
with prosthesis (Shea, 1957)
 BAHA implantable device

39. Audiometric Results with Otosclerosis
 Degree:
 Type:
 Tympanogram:
 Reflexes:
 OAE:
 ABR: IWI
 Lowest level of wave V
 Overall latencies of wave V