41 - change in hearing, 42 - ear pain Flashcards
basic physopligy of middle / inner ear for hearing
Middle Ear: Sound waves travelling through air converted to sound waves travelling through fluid via eardrum and ossicles (malleus, incus and stapes).
Inner Ear: Cochlea, a fluid filled (endolymph) spiral. Motion in the endolymph from a particular resonance causes action potential generation of hair cells.
Auditory nerve travels to cochlear nucleus of brainstem then to inferior colliculus and thalamus.
2 functions of CNVIII
Sound and balance
Difference between rinnes and webers
Webers on forehead for lateralising.
Rinne’s of bone versus air conduction.
What does a result of rinnes mean
If R’s is positive then defect is conductive.
What does a webbers test show
W lateralisation indicates conductive loss on ipsilateral side or sensorineural deficit contralaterally. Thus, distinguish with Rinne’s.
What is otitis media?
Sx?
Inflammatory disease of middle ear.
Fever, ear pain, bulging eardrum – can perforate,
What more sinister conditions might look a bit like otitis media
meningitis, mastoiditis, facial nerve paralysis
abx in otitis media?
If sx dont improve after 4d
5day of amox
Drugs which cause deafness>
Abx: gentamycin
Loop diuretics: furosemide
Chemotherapy: cisplatin, carboplatin, vincristine
Other: quinine, mercury, aspirin,
Triad of menieres
intractable vertigo
tinnitus
hearing loss
Mx of menieres
betahistidine and antiemetics for sx
Sx of acoustic neuroam
unilateral hearing loss, loss of balance, tinnitus, otalgia and mass effect
What can vestibular schhwannoma (acoustic neuroma) progress to?
cerebellopontine angle syndrome.
With tremors and speech disturbance.
sx of otitis externa
Ear pain; worse on movement, swelling of canal, decreased hearing. Usually no fever.
Mx of otitis externa
ofloxacin / acetic acid drops
