otology

Question 1

Middle ear is connected to the nasopharynx by what?

Answer 1

eustachian tube - provides ventilation and mucociliary clearance to the middle ear

Question 2

where is the pars tensa, malleus, and pars flaccid

Answer 2

When looking at the ear drum, pars tensa is inferior to the umbo and malleus, malleus forms an oblique line, and pars flaccid is superior to the malleus

Question 3

What does an audiogram measure

Answer 3

It measures hearing level (in dB) as a function of frequency (Hz). These pure tone thresholds measure the sensory (cochlear) aspect of hearing function

Question 4

What is the minimum dB humans can detect

Answer 4

Humans can detect a one dB difference. On the audiogram, 0 dB is the normal hearing threshold, not zero sound intensity

Question 5

What is a word recognition score

Answer 5

Represents the ability to discrimination words presentenced at normal conversational loudness levels (0-100%). This is a critical part of the hearing assessment and represents the “neural” aspect of hearing ability (inner hair cell, 8th nerve and central auditory pathways)

Question 6

Four types of hearing loss and what structures are affected

Answer 6

conductive (external ear, tympanic membrane or middle ear), sensory (cochlear), neural (8th nerve, inner hair cell, central pathways), or sensorineural (combo of sensory and neural structures)

Question 7

causes of conductive hearing loss

Answer 7

otitis media, TM perforation, Cholesteatoma, Otosclerosis (bones become fixed), Congenital aural atresia

Question 8

signs and symptoms of acute otitis media

Answer 8

Rapid onset of signs (inflammation of TM, drainage, perforation) and symptoms (pain, fullness/pressure, hearing loss) of an ear infection in the presence of a middle ear effusion.

Question 9

treatment of acute otitis media

Answer 9

1) Consider Watchful Waiting when uncertain in low-risk patients 2) Systemic Abx 3) Tympanocentesis for culture or acute pain control 4) Myringotomy and Mastoid Surgery in complicated cases

Question 10

otitis media with effusion- signs/symptoms and treatment

Answer 10

Middle ear fluid in the absence of inflammation/infection. Pain/fullness/popping /hearing loss (can delayed speech and language development), recurrent episodes of AOM. Antihistamines, decongestants, antibiotics, steroids not effective. Treat with time (watchful waiting) or PE tubes

Question 11

causes of sensory hearing loss

Answer 11

hair cell loss due to presbycusis, noise trauma, ototoxicity, genetic factors. Outer hair cells more susceptible than inner hair cells.

Question 12

what is presbycusis

Answer 12

Gradual, progressive bilateral hearing loss caused by degenerative physiologic changes associated with aging. Decreased hearing threshold sensitivity. Decreased ability to understand supra-threshold speech. Central auditory process impairment. Associated with greater risk of alzheimers and other cognitive declines

Question 13

What are the OSA regulations for chronic noise exposure

Answer 13

80 dB for 8 hrs or 90 dB for 4 hours

Question 14

What is a noise notch

Answer 14

A form of sensory hearing loss where the audiogram shows normal hearing at low frequencies, then an abrupt decrease in hearing level in dB at a high frequency (ie. 4000Hz) but then hearin level in dB goes back up to near normal at higher frequencies (ie. 8000Hz). This occurs around 2000-4000Hz becuase the resonant frequency in the middle ear is around this frequency

Question 15

What is ototoxicity

Answer 15

Ototoxicity is the tendency of certain therapeutic agents and other chemicals substances to cause functional impairment and cellular degeneration of the tissues of the inner ear, especially the inner ear hair cells and stria vascularis

Question 16

common ototoxic agents

Answer 16

aminoglycosodes (gentamicin), cancer agents (cis-platinum), macrolides (erthromycin), ASA, quinine, loop diuretics, hydrocodone, viagra

Question 17

treatment of ototoxicity

Answer 17

stop agent, use corticosteroids, antioxidants (vitamin E), avoid noise exposure

Question 18

Two types of genetic causes of hearing loss

Answer 18

non-syndromic (70%) and syndromic (30%)

Question 19

most common causes of non syndromic hearing loss

Answer 19

Connexin 26 (autosomal recessive)

Question 20

most common causes of syndromic hearing loss

Answer 20

include Waardenburg’s (2%), Usher’s (4-5%), Pendred’s (5%), Brachio-oto-renal (7%), Alport’s (1%), and Jervell, Lange Nielson (0.25%).

Question 21

What is endolymphatic hydrops

Answer 21

A pathologic condition characterized by expansion of the endolymphatic compartment of the inner ear. Is associated with recurrent episodes of vertigo, sensorineural hearing loss, tinnitus and aural fullness that is refered to as Meneire’s disease

Question 22

stria vascularis function

Answer 22

maintains proper endolymph fluid homeostasis and the endonuclear potential by pumping K ions into the scala media

Question 23

How does loss of endonuclear potential affect hearing

Answer 23

it causes sensory hearing loss

Question 24

Causes of disordered inner ear fluid homestasis and treatment

Answer 24

Impaired blood flow due to: Vascular dysfunction/ vasculitis, systemic metabolic disorders (DM, hypothyroid, renal failure, arteriosclerosis), immune mediated (lupus, sarcoidosis, wegeners). Treated with corticosteroids

Question 25

hallmarks of neural hearing loss

Answer 25

asymmetry of hearing between the two ear and reduced speech perception scores.

Question 26

Causes of neural hearing loss

Answer 26

8th nerve tumors, auditory neuropathy, multiple sclerosis

Question 27

management of vestibular schwannoma

Answer 27

observation, resection, stereotactic radiosurgery

Question 28

treatment of sensorineural hearing loss

Answer 28

Air Conduction Hearing Aids, Implantable Hearing Aids, Cochlear Implants, Assistive Listening Devices, Speech and Language Training