Quiz 1: Outer, Middle, Inner Ear Flashcards
The ossicles convert ___ energy into mechanical energy and amplify it, transferring it to the __ window of the cochlea
Sound
Oval
The eustachian tube is opened by which muscle?
Tensor veli palantini
Endolymph is found in the membranous labyrinth and has a high concentration of _____ and a lower concentration of ______.
Potassium
Sodium
(The only place in the body where this is found)
Which cranial nerve innervates the cochlea?
CN VIII
Track the structures that convert sound energy into a nerve impulse.
Outer ear –> ear canal –> TM –> ossicles –> cochlea –> endolymph –> organ of corti –> CN VIII –> temporal lobe
What is the name of the vascularization system that supplies blood to the inner ear?
Stria vascularis
The organ of corti is stimulated by the flow of _____ ions.
Potassium
Osteoma most often occurs in individuals with what hx?
BONUS POINT: which homeopathic?
History of cold-water exposure (swimmers or surfers).
Hekla lava.
When is AOM worse?
Evening
What is a sign in children, especially infants, that they might have AOM?
Anorexia
A retracted TM with a yellow to amber color and fluid would suggest _____ rather than _____.
Otitis media with effusion.
Rather than acute otitis media.
What is a highly specific finding upon otoscopy with AOM?
Bulging TM.
Spin— Specific rules in. If TM is bulging, very likely AOM.
What is a highly sensitive finding upon otoscopy with AOM?
Immobile TM.
Snout— Sensitive rules out. If TM is mobile, very likely not AOM.
An immobile TM that is retracted with a history of allergies suggests…
Otitis media with effusion.
In otitis media with effusion, Weber lateralizes to the _____ ear and Rinne will be _____>_____. What type of hearing loss is this?
Bad
BC>AC
Conductive
OME and AOM will show which type of tympanometry?
B type, a flat line
An infant rectal temp above _____, or oral above _____, mild ear fluid, tympanic erythema, might suggest _____. What other PE findings would you look for to rule in or out your dx?
100.4 F
99.5 F
AOM
Bulging ear drum
Immobile TM
Loss of bony landmarks
Complications: AOM (4)
Mastoiditis
Meningitis
Perforated TM
Cholesteatoma
Which bacteria are associated with suppurative complications?
P. aeruginosa
S. aureus
S/sxs: Mastoiditis (5)
Bulging in the canal Protrusion of the auricle Red behind the ear Mastoid TTP High fever
Use ______, ____, or _____ to soften cerumen.
Debrox
Calendula oil
Olive oil
Why should you not irrigate beans and grains to remove them from the ear canal?
They can swell and become more difficult to remove.
What is the main contraindication for irrigating the ear canal?
Perforation of the tympanic membrane.
Name some risk factors for OM. There are a lot.
Cranial facial bone structure Allergies Dairy Prone sleeping Second hand smoke Race: native north american Vit D deficiency < 18 months Season: incidence increases in fall, highest in Feb, decreases in the spring Weaning from breast milk Beginning school or day care
Supine bottle feeding with snuffles that causes aspiration in to the eustachian tubes is called…
Toynbee phenomena
Tx failure in otitis externa correlates most with…
Failure to clean out the canal (aural toilet [also, wtf?]).
Incorrect diagnosis.
Benefits of Abx in OM:
Decrease in mastoiditis
Decrease in meningitis
(Though recent reports suggest that untreated AOSM has similar rates of complications whether an antibiotic are prescribed or withheld)
Good tx for < 2yo with bilateral OM
The NNT to reduce pain with Abx.
16 patients (17%)
Risk of Abx use in OM.
Increased rate of recurrence.
Increased bacterial resistance.
Infectious chondritis ____ the lobe and is usually unilateral, while relapsing polychondritis _____ the lobe and is usually bilateral.
Includes
Spares
Risk factors: otitis externa
Change in pH from acid to alkaline
Increased temp and humidity
Mild trauma, frequent cleaning
Hx: otitis externa
Swimming
Trauma
Dermatitis
Q-tip abuse
Malignant otitis externa affects immunocompromised patients particularly…
Those with DM, alcoholism, severe malnourishment.
What may you see in the ear canal of Malignant OE?
Granulation tissue
Complications: Malignant OE
Osteomyelitis, hearing loss, facial nerve paralysis, death.
Next steps: Suspected malignant OE in office.
Refer to ENT for MRI or CT.
DDx: ear pain with WNL otoscopic exam and no loss of hearing.
Referred Pain from: TMJ (most common) Molar Cervical spine pain Malignancies
Red flag pts with referred ear pain include:
Smokers Alcohol abuse >50 yo DM (These pts have a higher risk of a serious occult cause of ear pain)
Which Abx ear drop is indicated in tx of OE and perforated TM? Why?
Fluoroquinolone due to excellent coverage for Pseudomonas and lack of ototoxicity.
Homeopathy: OE
Hepar sulph:
Most common bacteria found in AOM:
S. pneumonia
Homeo: What do you look at when deciding if AOM sxs are an exacerbation of a chronic state or a true acute?
Physical generals. If it is a new PG then give an acute.
Are Abx effective for OME?
No
What is a helpful question to ask a pt with a cc of dizziness?
Ask the pt to describe their sxs without using the term dizziness.
An internal sense of spinning or the feeling that the room is spinning around oneself is called:
Vertigo
Most common cause of vertigo can be found in the _____ ____.
Peripheral labyrinth
What are common types/origins of “dizziness” a patient might describe?
Vertigo
Syncope or presyncope
Disequilibrium
Lightheadedness (wastebasket term)
What are pre-syncope and syncope, and what organ system should you always think of first with these?
Pre-syncope: lightheadedness, muscular weakness, blurred vision, feeling faint.
Syncope: loss of consciousness and posture, described as “fainting” or “passing out.”
Think CARDIAC first!
Most common cause of both is a sudden drop in blood pressure.
Peripheral vertigo refers to dysfunction somewhere in the _____ or ____ ear.
Middle
Inner
Peripheral vertigo: nystagmus is ______ and _____.
Unidirectional
Horizontal
Central vertigo refers to dysfunction of the ____ ___ or _____.
Brainstem
Cerebellum
Central vertigo: Nystagmus qualities?
Bidirectional
Downbeat aka true vertical
Sxs of central vertigo include:
Weakness, dysarthria, vision changes, paresthesia, altered mental status, ataxia or other motor/sensory
What is the most useful physical exam for differentiating peripheral and central vertigos? How to interpret?
Head Impulse Test (test vestibular-ocular reflex).
In peripheral vertigo, you will perceive a “catch-up” saccade after when the head thrust is in the direction of the lesion.
(Test will be negative in central vertigo).
What direction of nystagmus implies BPPV (peripheral vertigo) upon Dix-Hallpike maneuver?
Upbeat
Downbeat implies central vertigo
