ENT I Flashcards
what occurs if there’s a mismatch of the bilateral labyrinth system?
vertigo
semicircular canals - what are they and types?
Organ for body movement
-posterior semicircular canal, lateral, superior
posterior semicircular canal detects what?
when head tilts down towards shoulder
lateral semicircular canal detects what?
when head shakes side to side, “no”
superior semicircular canal detects what?
when head nods up and down, “yes”
organ for hearing?
cochlea
what do otolith organs sense? names?
gravity and linear acceleration
-motion according to their orientation
names: utricle and saccule
utricle
otolith organ
- horizontal in head
- registers acceleration in horizontal plane
saccule
otolith organ
- vertical in head
- registers acceleration in vertical plane
what is CN VIII responsible for?
vestibulocochlear nerve
-responsible for balance and orientation in space and auditory function
where does the Eustachian tube run?
anterior wall of middle ear to open in nasopharynx
what ends are wider in Eustachian tube?
nasopharyngeal and tympanic ends are wider than middle of the tube
what is narrowest protein of ET tube?
bony isthmus
when is the ET tube open and closed?
normally closed
-only open during swallowing and yawning
what is ET tube most important normal function?
equalization of pressure across tympanic membrane
types of ET tube dysfunction (HINT: 2)
dilatory and patulous
what is dilatory ET tube dysfunction?
-cartilage portion of tube doesn’t dilate
causes of dilatory ET tube dysfunction?
- inflammation
- pressure dysregulation
- acquired anatomic abnormalities
what is patulous ET tube dysfunction?
valve incompetency -> chronic patency
-STUCK OPEN
dilatory ET tube dysfunction HALLMARK presentation
accompanying symptoms of hearing loss and abnormalities of the tympanic membrane
- retraction
- middle ear effusion
what will you see on otoscope exam for dilatory ET tube dysfunction?
- effusion
- scarring
- thickening of TM (if chronic)
what might TM have on dilatory ET tube dysfxn?
- retractions
- effusion
- cholesteatomas
- perforations
- plaques
patulous ET tube dysfxn HALLMARK presentation
autophony (pt hears own voice amplified) & ear fullness
what is patulous ET tube dysfxn worsened by?
exercise and prolonged speaking
PE findings for patulous ET tube dysfxn?
breathing induced excursions (movements) of TM and sensorineural hearing loss
what will weber test reveal for dilatory ET tube dysfxn?
lateralization to affected ear -> conductive hearing loss
what are the differences in types of hearing loss for patulous and dilatory ET tube dysfxn?
patulous -> sensorineural
dilatory -> conductive
treatment of dilatory ET tube dysfunction?
treat underlying etiology
- antihistamines
- decongestants (Zyrtec)
- nasal steroids
- vaslsalva
treatment of patulous ET tube dysfxn?
- treat if severe symptoms >6 weeks
- ventilation tubes in severe cases (equalize pressure)
- hydration and mucous thickening agent
what do you do for both patulous and dilatory ET tube dysfunction?
REFER TO ENT
- nasal endoscopy
- CT or MRI w/contrast if >3 months of unilateral sx’s or middle ear effusion
- surgery if mass found
- balloon dilation
is vertigo a symptom or diagnosis?
SYMPTOM
what are the key to diagnosis of vertigo?
duration of episodes and association with hearing loss
what is affected in peripheral vertigo?
semicircular canals, otolith organs
what is affected in central vertigo?
cerebellum, CN VIII, brainstem
what is the balance center of the brain?
cerebellum
why does vertigo occur?
damage to CNS integrate sensory input and asymmetrical signal is sent
causes of peripheral vertigo
- Benign paroxysmal positional vertigo
- Vestibular neuritis (AKA labrythitis)
- Meniere’s Disease
- Herpes zoster oticus
- Acoustic neuroma
- Aminoglycoside toxicity
- Superior semicircular dehiscence syndrome
causes of central vertigo
- Migraines
- Cerebral tumor on VIII
- Chiari Malformation
- Brain ischemia (cerebellar infarct) - Ie. Vertebrobasilar stroke
- TIA
- MS
clinical presentation of peripheral vertigo
- sudden onset
- tinnitus & hearing loss
- +/- nystagmus
clinical presentation of central vertigo
gradual onset, no auditory symptoms like in peripheral vertigo
what is the most common cause of vertigo?
benign paroxysmal positional vertigo (~50%)
what is benign paroxysmal positional vertigo provoked by?
head movements like turning in bed, tilting head backward to look up
what is benign paroxysmal positional vertigo caused by?
calcium debris in semicircular canal (posterior canal most common)
-aka Canalithiasis
clinical presentation of benign paroxysmal positional vertigo
- rapid onset of dizziness or spinning (vertigo) that lasts seconds to minutes
- nystagmus (classic is clockwise)
- sensation of motion with sudden head movements
- NO ear pain, hearing loss, tinnitus
dx of benign paroxysmal positional vertigo
Dix-hallpike positional testing
- Clockwise, rotary nystagmus – fatigable with repetition
- Latency of 5-15 seconds between supine position and onset of nystagmus
- Induced the vertigo and nystagmus
further testing for benign paroxysmal positional vertigo (if needed)
- electronystagmogaphy (records eye movements)
- MRI/CT to r/o CVA or bleed
MRI COMES BEFORE CT
txt of benign paroxysmal positional vertigo
-txt is symptomatic b/c resolves w/in months
what is first line txt for benign paroxysmal positional vertigo?
antihistamines
after antihistamines, what do you use to treat benign paroxysmal positional vertigo?
- antiemetics, Benno’s, scopolamine
- vestibular rehab
- surgery (only after 6 months)
vestibular rehab for benign paroxysmal positional vertigo
- epley maneuver to shift stone around - 3 different positions
- also do gaze stimulation exercises
vestibular neuritis (aka labrynthitis)
viral or post-viral inflammatory disorder affecting vestibular portion of CN VIII
-benign and self-limited
vestibular neuritis vs labrynthitis
vestibular neuritis: vertigo w/out hearing loss
labrynthitis: vertigo w/unilateral hearing loss on affected side
symptoms of vestibular neuritis (aka labrynthitis)
- Rapid onset of severe, persistent vertigo
- Gait instability
- Decreased hearing in 1 ear for labrynthitis
- Horizontal nystagmus
- Positive head thrust
- Nystagmus is suppressed with visual fixation
- If patient falls it is toward the affected side
- +/- unilateral hearing loss
imaging for vestibular neuritis (aka labrynthitis)
MRI/MRA for infarct
-MRA looks at blood vessels
CT if MRI/MRA not available
when would you do imaging for vestibular neuritis (aka labrynthitis)?
if concern for lesion or stroke in cerebellum causing symptoms
txt of vestibular neuritis (aka labrynthitis)
-steroid therapy (may improve recovery)
-antihistamines, antiemetics
, vestibular rehab
prognosis of vestibular neuritis (aka labrynthitis)
- self-limiting
- few days-week
- may have nonspecific dizziness and imbalance for months
when would you do vestibular rehab for vestibular neuritis (aka labrynthitis)?
After acute symptoms subside with aggressive proprioception and balance exercises
Meniere’s disease
- Peripheral vestibular disorder attributed to excess endolymphatic fluid pressure
- Causes episodic inner ear dysfunction
what is affected in Meniere’s disease?
Labyrinth/inner ear
- Cochlea
- Semicircular canals
- Otolithic organs
Risks of Meniere’s disease
allergy, stress, viral
Meniere’s clinical presentation
- vertigo
- unilateral sensorineural hearing loss
- unilateral tinnitus
- ear fullness
- disabling imbalance
- horizontal-torsional nystagmus in acute attack
unpredictable episodes of Meniere’s last how long and followed by what?
may last hours, recurring, followed by fatigue
spontaneous episodes of Meniere’s disease last how long?
20min-24 hours
imaging for Meniere’s
audiometry - positive low frequency sensorineural hearing loss
electronystagmography - pos unilateral reduced vestibular response
caloric testing - shows loss/impairment of thermally induced nystagmus on affected side
is there a specific Meniere’s test?
NO!
txt for Meniere’s does what/
relief of symptoms but doesn’t address underlying pathology
goals of txt for Meniere’s?
- Reduce frequency and severity of vertigo attacks
- Reduce or eliminate hearing loss and tinnitus associated with attacks
- Minimize disability
- Prevent disease progression (mostly hearing loss and imbalance)
txt for acute symptoms of Meniere’s
- Antihistamines
- Antiemetics
- Benzodiazepines
- Anticholinergics (Scolpolamine)
long-term txt for Meniere’s
- Lifestyle adjustments
- Salt restriction
- Limit caffeine and nicotine
- Limit alcohol
- If tinnitus, avoid excessive noise
non-destructive txt procedures for Meniere’s
Surgical: On endolympathic sac and succolotomy
-Can cut a hole in the top and let excess fluid drain out
- Intratympanic steroids
- Positive pressure pulse generator
destructive txt procedures for Meniere’s
Intratympanic gentamicin injection (Kills everything)
Surgical laburinthectomy (Deafness in that ear results)
Vestibular nerve resection
(Cut vestibular portion of CN VIII)
semicircular canal dehiscence syndrome
Thinning of the bone that separates the superior semicircular canal from middle cranial fossa
-Allows pressure to be transmitted into inner ear
how is vertigo provoked in semicircular canal dehiscence syndrome?
coughing, sneezing, valsalva, loud sounds (Tullio phenomenon)
what establishes dx for semicircular canal dehiscence syndrome?
high resolution Ct of the temporal bone
tinnitus epidemiology
- children
- increases w/age
- men>women
- smokers
will chronic tinnitus remit completely
no, but often becomes less bothersome over time
types of tinnitus (HINT: 2)
pulsatile, non-pulsatile
pulsatile tinnitus sounds like and seen it what disorders?
- Like listening to own heartbeat
- Vascular disorders
- Arteriovenous shunts
- Venous hums
- Eustachian tube dysfunction
- Arterial bruits (worse in quiet environment)
non-pulsatile tinnitus
- Clicking tinnitus (secondary to middle ear spasm)
- Unilateral
causes of tinnitus
- ototoxic meds
- presbycusis
- otosclerosis
- chiari malformations
how do ototoxic meds cause tinnitus?
Affects various components of the cochleovestibular end-organ
presbycusis and tinnitus
- Sensorineural hearing loss with aging
- Any acquired high frequency loss commonly associated with tinnitus
otosclerosis and tinnitus
Condition of abnormal bone repair of the stapes footplate bone
chiari malformations and tinnitus
Occurs when low lying cerebellar tonsils cause tension on the auditory nerve
history for diagnosing tinnitus
- get description of tinnitus
- ask about previous ear disease, noise exposure, hearing status, head injury, symptoms suggestive of TMJ
- review all meds and supplements
- review medical conditions
- ask if difficulty hearing or hearing loss
medical conditions associated with tinnitus
HTN, atherosclerosis, neurologic illness, prior surgery
physical exam for tinnitus
- Complete HEENT
- Cranial nerve exam
- Evaluate tympanic membrane
- Auscultate the neck, periauricular area, temple, orbit, mastoid
- Effects of positioning on vascular compression of the neck on side involved should be noted
what to avoid with tinnitus?
excessive noice and ototoxic and other drugs that damage cochlea
txt for tinnitus
-Correct identified comorbidities and mitigate their effect of tinnitus
-Treat underlying depression and insomnia
-Cochlear implants in cases of severe sensorineural hearing loss
-Tinnitus retraining therapy
Bio-feedback cognitive therapy as adjunct
