ears review

external ear

auricle/pinna → cartilage + skin, funnel shape amplify sound

ear canal → cartilage (oiuter) + bone (inner)

cerumen → lubricate and protect canal

cilia → filter debris

external ear: ends at

tympanic membrane

frint surface

external ear: landmarks

helix

antihelix

tragus

antitragus

lobule

concha

external ear: lymph drainage

parotid

mastoid

superficial cervical nodes

middle ear

begin on medial side of TM 3 ossicles

• malleus (hammer) → attach to TM

• incus (anvil) → middle bone

• stapes (stirrup) → smallest bone, connect to oval window

bone in body → connect to oval window

middle ear: eustachian tube

connects to nasopharynx

equalize pressure

middle ear: TM

separate external from middle ear

inner ear

bony labyrinth

balance

hearing

CN VIII → carries impulse to brain

mastoid process → behind ear

• tender = mastoiditis

inner ear: balance

vestibule

semicircular canal

inner ear: hearing

cochlea

coiled

hair cells convert vibration → nerve impulse

Normal TM

color: pearly-gray, translucent

position: flat, not bulge/concave

landmarks: malleus, umbo, short process

cone of light:

• 5 o’clock → R ear

• 7 o’clock → L ear

intact, shiny, movable

abnormal TM

red + bulge = acute otitis media

yellow fluid/bubbles = serous otitis media

blue/dark red = blood behind TM → skull trauma

white spot = tympanosclerosis → scarring

hole = perforation; foul discharge

bloody/watery drainage = possible CSF → EMERGENCY

no flutter with pneumatic bulb = fluid/infection behind TM

otoscope pina direction

adult

• pull pinna UP → BACK

children < 3

• pull pinna DOWN → BACK

cerumen types

dry

• gray flaky

• asian

• native americans

wet

• honey-dark brown

• african american

• caucasians

hispanic

• impacted cerumen

• conductive hearing loss

sound pathway

pinna → canal → TM → malleus → incus → stapes → oval window → cochlea → hair cell → CN VIII → brain

sound pathway: air conduction (AC)

normal

most efficient

sound pathway: bone conduction (BC)

alternate route

bypasses outer/middle ear

normal: AC > BC (2:1 ration)

conductive hearing loss

blocked

location: external or middle ear

causes:

• impacted cerumen

• pus/fluid in middle ear

• torn/perforated TM

• tympanosclerosis (scarring)

• otosclerosis (stapes fixation)

• stiff/coarse cilia (elder)

• canal swell (otitis externa)

weber test → affected ear

rinne test → BC > AC

sensorineural hearing loss

nerve

location: cochlea or CN VIII

causes:

• presbycusis (elder)

• ototoxic drug

• prolonged loud noise

• maternal rubella (1st trimester)

• acoustic neuroma (CN VIII tumor)

• genetic/congenital

decreases consonants; worse with background noise

weber test → unaffected ear

rinne test → AC > BC, < 2:1 ratio

mixed hearing loss

conductive and sensorineural

weber test

detect unilateral hearing loss

technique: strike tuning fork → stem on top center of skull

ask pt where they can her it

normal

• equally in both ears

conductive

• affected ear

sensorineural

• unaffected ear

rinne test

compare air conduction (AC) to bone conduction (BC) in same ear

technique:

• strike fork → STEM mastoid process (BC)

• pt no longer hear → move prongs to from ear canal (AC)

whisper test

occlude one ear

pt pushes tragus rapidly in/out

examiner whisper 3 words 1-2 ft away

normal = pt repeat correctly

pure tone audiometer

earphones

pt raise hands on same side

measure frequency, timing, decibels one ear at a time

pneumatic otoscopy

puff air at TM

normal = flutter

abnormal = no movement

• fluid/infection behind TM

moro reflex

infants

loud noise → startle reflex

absent = hearing concern

tinnitus

ringing, buzzing, or crackling in ears

worsen at nights

tinnitus medication cause

salicylates

• reversible at lower dose

• early warning sign

aminoglycosides

• cause permanent sensorineural loss

glycopeptides

• toxic with aminoglycosides

loop diuretic

• reversible

• potentiates aminoglycoside toxicity

chemotherapy

• cumulative

• permanent sensorineural loss

tinnitus other causes

presbycusis → aging sensorineural degeneration

loud noise exposure → work, concer, earbuds

otitis media → fluid/infection middle ear

impacted cerumen → pressure TM

TMJ disorder → referred sensation

HTN/CV → pulsatile tinnitus (whoosh with heartbeat)

meniere disease → vertigo + tinnitus + sensorineural

acoustic neuroma → benign CV III tumor

hearing through ages: fetus

hears in utero by 7-8 mo

maternal rubella in 1st trimester → sensorineural hearing loss

hearing through ages: newborn

hearing test is required by law before hospital discharge

ears/kidney develop at same time in utero

external ear deformity

• check kidney deformities

• moror reflex

hearing through ages: infant/toddlers

shorter, wider, straight eustachian tube

OM affects ~90% under 2

supine bottle feed → fluid in eustachian tube → OM

upright breastfeed = lower risk

hearing through ages: children

hearing test all public school

TM exam every childhood fever

“inattentive” child → hearing test

chronic OM fluid → impaired hearing → delay cognitive dev

OM risk factors

daycare

secondhand smoke

male

pacifier use

supine bottle feed

fall/winter

age < 2

otitis media

middle ear infection → behind TM

TM

• red

• bulging

• no cone of light

can cause

• hearing loss

• delayed dev

• TM rupture

otitis externa

swimmers ear → infected canal

pain with tragus push or pinna pull

canal: red, swollen, discharge

cause

• swim

• humid env

treatment

• topical antibiotic ear drop

aging pt: presbycusis

gradual sensorineural loss (40-50s)

degeneration of cochlear hair loss/CN VIII nerve fibers

• Decreased hearing of high-frequency sounds and consonants (S, F, SH, CH)

• Background noise makes comprehension significantly worse

• "I can hear people talking but can't understand the words"

• Bilateral and gradual — patient often unaware of early changes

• Auditory reaction time slows after age 70

aging changes

coarse, stiff cilia → conductive, cant move cerumen out

few sebaceous glands (dry wax) → conductive, hard cerumen build up/ block canal

tympanosclerosis → conductive, TM scarring from past infection

nerve degeneration (cochlea + CN VIII) → sensorineural, progressive hair cell/nerve fiber loss

prolonged noise exposure → sensorineural, cumulative damage hair cells

ototoxic drug → sensorineural, aspirin, aminoglycosides, vancomycin damage cochlea

otosclerosis

bony fixation of stapes → conductive loss in adults

surgical treat = stapedectomy

tinnitus in elder

ringing, buzz, crackling at night

CN VIII

vestibulocochlear (acoustic)

cochlear branch → transmit hear impulse from cochlea to brain

vestibular branch → transmit balance semicircular canal/vestibule to brain

test: rinne, weber, whisper, audiometry

damaged by:

• ototoxic drug

• acoustic neuroma

• viral infection

• aging

• trauma

CN VIII damage effects

sensorineural hearing loss

tinnitus

vertigo/balance problem

Meniere's disease: affects both branches, hearing loss + tinnitus + vertigo

acoustic neuroma: benign CN VIII tumor, unilateral progressive loss + tinnitus

otoscope: adult/older children

1. Test light on palm (brightness check)

2. Largest speculum cover (4.0 size)

3. Pull pinna UP and BACK

4. Hold otoscope upside down; brace hand

against patient's face

5. Patient tilts head away; examiner closes

opposite eye

6. Insert gently, aim toward nose

children under 3 yr

1. Smaller speculum (2.0 size)

2. Pull pinna DOWN and BACK

3. Parent holds child firmly (head + limbs)

4. Demonstrate on parent first

5. Save ear & mouth exams for LAST (most

upsetting)

6. TM exam with EVERY fever

Inspect, palpate & otoscope — what to look for: external inspection

 Same height/size/shape bilaterally

Helix, tragus, antihelix, lobule: redness,swelling, nodules, lesions

Darwin's tubercles on helix = normal variant

Inspect, palpate & otoscope — what to look for: external auditory meatus

Visible opening? Swelling? Redness? Discharge?

Note cerumen color, consistency

Inspect, palpate & otoscope — what to look for: palpation

Push on tragus (pain = otitis externa) and mastoid process (pain = mastoiditis)

Palpate auricle for nodules/masses

Inspect, palpate & otoscope — what to look for: TM

Color (pearly gray?)

position (flat?)

landmarks (malleus, umbo visible?)

cone of light (5 o'clock R / 7 o'clock L)

integrity (intact? scarring?)

movement with pneumatic bulb (should flutter)

subjective question

Pain?

Discharge?

Hearing loss?

Tinnitus?

Vertigo?

Loud noise exposure?

Ototoxic medications?

Hearing aids?

How do you clean your ears?