Otitis Media With Effusion

Question 1

What is Waldeyers ring?

Answer 1

A ring of lypmhoid tissue in the walls of the pharynx comprised of the palatine, lingual, pharyngeal and tubal tonsils.
Acts to protect the entrance to the digestive and respiratory tracts from infection.

Question 2

Describe the Palatine tonsils?

Answer 2

Found between the palatoglossal and palatopharyngeal folds.
Well developed in children.
Rich arterial supply from the facial artery.

Question 3

Describe the Pharyngeal tonsils location?

Answer 3

Found in the superior posterior nasopharynx.

Question 4

Describe the lingual tonsil location?

Answer 4

Posterior 1/3rd of tongue beneath the mucosa.

Question 5

Describe the Tubal tonsils location?

Answer 5

Around the tubal elevation of the Eustascian tube.

Question 6

Describe epithelia of the tonsils?

Answer 6

Tubal and pharyngeal has respiratory eipthelium (pseudostratified columnar with goblet cells).
Lingual and palatine tonsils have stratified squamous epithelium.
They have M cells which engulf pathogens into the tonsil.

Question 7

What is acute otitis media and otitis media with effusion?

Answer 7

Acute OM is a middle ear infection with inflammation. Symptoms include pain, irritability and fever.

OM with effusion is an infection of the middle ear with the presence of fluid. Usually occurs as an inflammatory response after acute OM. Hearing loss is of around 25dB.

Question 8

Describe the pathophysiology of OM with effusion?

Answer 8

An upper respiratory tract infection may cause swelling in the tonsils. The tubal tonsils surrounds the eustascian tube. If this becomes closed over, air cannot enter.
Goblet cells produce mucous and serous fluid which builds up.
Persistent middle ear infection can lead to decreased mobility of the tympanic membrane resulting in poorer sound conduction.

Question 9

List risk factors for OM with effusion?

Answer 9

aged 3 months - 3 years, due to shorter and more horizontal eustascian tube.
Premature birth.
Bottle fed babies as they are held more horizontal and can get milk reflux into the middle ear.
Males.
Having orofacial abnormalities e.g. cleft palate, if the muscle that opens the tube is affected.

Question 10

How is OM with effusion treated?

Answer 10

Grommets (ventilation tubes) are inserted under general anaesthetic via a small incision in the eardrum.
This helps drain fluid and maintain air pressure in the middle ear. Can also improve hearing by around 12dB.
As the eardrum heals it is slowly pushed out and it falls our around 6-12 months after insertion.

Question 11

What is conductive hearing loss?

Answer 11

Usually in external or middle ear (external auditory canal to the stapes).
Occurs as sound cant reach the cochlea. 
Due to;
- Obstruction
- Mass loading (middle ear effusion)
- Stiffness (otosclerosis)
- Discontinuity (ossicular disruption)

Question 12

What is Sensironeural hearing losss?

Answer 12

Occurs in inner ear (sensory) or as part of the VC pathway (neural). Often permanent as hair cells have limited ability to repair themselves. 
Due to;
- Long term exposure to loud sounds. 
- Trauma 
- Aging 
- Ototoxic medication e.g. Gentomycin.

Question 13

Name 2 tests to test hearing?

Answer 13

Rinnes and Webers test.

Question 14

How does Rinne’s test work?

Answer 14

Tuning fork is placed on mastoid bone and once vibrations cannot be heard it it held at the external ear, ask if vibrations can be heard.
Should be able to hear vibrations for longer at the eternal ear as air conduction is heard louder than bone conduction.
If bone conduction appears louder = conductive hearing loss in that ear.

Question 15

How does Weber’s test work?

Answer 15

Tuning fork is placed in centre of forehead and patient is asked which ear is louder.
Should be heard equally.
It lateralises towards conductive loss and away from sensironeural loss.
e.g. If louder in right ear - either right conductive loss or left sensorineural loss.

Question 16

List effects of hearing loss.

Answer 16

The earlier the hearing loss, the more profound affect it has on development.

Delay in speech and language development.
Poor vocabulary and sentence structure.
Academic achievement affected.
Psychosocial factors - school, family, friends, hobbies.

Question 17

Describe hearing screening tests.

Answer 17

Newborn hearing tests are done before hospital discharge.
Automated Otoacoustic Emission test: Small earpiece is placed in babys ear and clicking sounds are played and the cochlea responds which is picked up by a computer.

If there is no clear response, they are referred for an Automated Auditory Brainstem Response test.
This involved playing sounds and trying to detect responses from the brainstem via electrodes.

Further tests are done in children from 8-12 months.
Then at 4/5 years usually in a community setting e.g. school.