Ear disorders and testing ear function Flashcards
What causes Ramsay Hunt syndrome?
Reactivation of VZV
in the geniculate ganglion of the CN7 facial nerve
What happens to the ear in Ramsay Hunt syndrome?
Vesicular rash on upper pinna
and external auditory meatus
Why is there a vesicular rash on the upper pinna and external auditory meatus in Ramsay Hunt syndrome?
Due to the facial nerve carrying sensory information from this part of the ear
What is a pinna haematoma?
Bleeding between the cartilage and perichondrium of the pinna
What causes a pinna haematoma?
Trauma
What are the complications of a pinna haematoma?
Necrosis of the cartilage in the pinna
Cauliflower deformity
What causes necrosis of cartilage in the pinna in a pinna haematoma?
Cartilage is avascular, perichondrium carries it blood supply
if blood accumulates between the two, separates the two
cartilage suffers avascular necrosis
What causes a cauliflower deformity of the pinna?
After necrosis of cartilage in pinna
fibrosis occurs
new asymmetrical cartilage may form
both as part of healing
How is a pinna haematoma treated?
Drain the blood from the pinna
re-align the cartilage and the perichondrium to give it back its blood supply
How can wax in the external auditory meatus affect ear function?
If it builds up and blocks the external auditory meatus
prevents sound vibrations reaching tympanic membrane
loss of hearing
What is otitis externa?
Inflammation of the external auditory meatus
What are the signs and symptoms of otitis externa?
External auditory meatus is red swollen painful contains exudate, discharge
What are the causes of otitis externa?
Infection
Allergy
What can predispose to otitis externa?
Swimming
Skin problems e.g. dermatitis (eczema)
What can cause perforation of the tympanic membrane?
External pressure
Inernal pressure due to infection of middle ear
increased pressure in middle ear
pushes against tympanic membrane
How is a perforated tympanic membrane treated?
It resolves itself
What can cause bulging of the tympanic membrane?
Infection of middle ear
increased pressure in middle ear
What is otosclerosis?
Ossicles fuse with each other where they normally articulate with each other
Which ossicle is most commonly affected by otosclerosis?
Stapes
What does stapes fuse with in otosclerosis?
Its base plate fuses with the oval window
How does otosclerosis of stapes with the oval window affect ear function?
Reduced vibration of stapes against oval window
loss of hearing
What is hyper-acusis?
Sensitivity to loud noises
What is one of the causes of hyper-acusis?
Problems with nerve to stapedius of facial nerve
reduced function of stapedius muscle
doesn’t control vibrations of stapes base plate against oval window when loud sounds are heard
What causes otitis media with effusion?
Reduced function of eustachian tube
increased negative pressure in middle ear cavity
draws transudate fluid out of mucosa lining middle ear cavity
What does otitis media with effusion predipose to?
Acute otitis media
How does otitis media with effusion affect ear function?
Reduced vibrations of tympanic membrane, ossicles
loss of hearing
How does otitis media with effusion affect the tympanic membrane?
Is retracted
because the negative pressure in the middle ear cavity draws it inwards
How is otitis media with effusion treated?
May resolve itself in a few months
Or use grommets