Ear Disorders II Flashcards
Mechanisms of conductive hearing loss
- obstruction
- mass effect
- stiffness effect
- discontinuity (fracture or head trauma)
What parts of the ear does conductive hearing loss involve?
external or middle
Common causes of conductive hearing loss?
Most common causes:
- cerumen impaction
- ETD
Other:
- otitis media
- otitis externa
- TM perf
- trauma
- otosclerosis
Mechanisms of Sensorineural hearing loss (hint: think about the name/what parts are affected)
- senory- dysfunction of inner ear (cochlea)
- Neural- dysfunction of CN VIII or brain
Causes of sensorineural hearing loss
Presbycusis Persistent noise exposure head trauma systemic dz acoustic neuroma multiple sclerosis auditory neuropathy
Weber test: explain conductive vs sensorineural results
conductive- sound lateralized to bad ear
sensorineural- lateralizes to good ear
Rinne test: explain conductive vs sensorineural results
Conductive- BC > AC
sensorineural- AC > BC
When a is having an audiogram, what is the threshold at which it is considered to be abnormal?
> 25 decibles (dB)
What would you see in an audiogram of a pt with conductive loss?
- bone conduction nl bilaterally
- AC poorer on affected side
What would you see in an audiogram of a pt with sensorineural loss (presbycusis)?
Downwards sloping (higher dB) towards higher frequencies
In any patient with new onset hearing loss without obvious pathology what do you do and why?
need quick referral to audiology
**idiopathic sudden sensorineural hearing loss can be treated with corticosteroids when caught early
What is tinnitus? What can it be a symptom of?
perception of abnormal ear or head noises (mild, hight-pitched sounds lasting secs to mins- ringing, buzzing, crickets)
Can be manifestation of hearing loss
Treatment of tinnitus
- avoid exposure to excessive noise and ototoxic agents
- masking
- meds (oral antidepressants)
Others:
- transcranial magnetic stimulation
- deep brain stimulation
How is Pulsatile tinnitus described/what can it indicate?
How is Staccato tinnitus described?
Pulsatile= listening to one’s heartbeat
can indicate vascular abnormality (gloms tumor, venous sinus stenosis, aneurysm)
Staccato= rapid series of pop or clicks w/ sensation of ear fluttering
Another name for Labrynthitis?
Vestibular neuritis
Presentation and cause Labrynthitis?
- acute onset, continuous, severe vertigo
- nausea common
cause:
-inflammation of inner ear-
often after viral URI
Tx of Labrynthitis
- abx of pt is febrile or w/ sx of bacterial infection
- vestibular suppressants (anticholinergics/antihistamines, benzodiazepines)
- anti-emetic meds
- oral steroids
Another name for Meniere’s disease? What is it?
Endolymphatic hydrops
a vertigo syndrome due to a peripheral lesion
What happens in Meniere’s disease?
- distention of endolymphatic comportment of inner ear
- sx wax and wane as endolymphatic pressure rises and falls
- can permanently damage inner ear structures
Clinical presentation of Meniere’s disease
- episodic vertigo w/ discrete spells lasting 20 mins-several hrs
- fluctuating sensorineural hearing loss
- Tinnitus- low tone, blowing/roaring quality)
- sensation of unilateral ear pressure (aural fullness)
Classic triad of Meniere’s
vertigo + hearing loss + tinnitus
How is Meniere’s diagnosed?
- referral to ENT, audiology
- Caloric testing
What if Meniere’s treatment aimed at? How is this done?
aimed at decreasing endolymph fluid pressure in inner ear
- diuretics
- low salt diet
- vestibular ablation w/ gentamycin (ototoxic)
- labyrinthectomy
What is another name for an acoustic neuroma? What is it? Where does it begin/go?
vestibular schwannoma
benign tumor of CN VIII
- begins in internal auditory canal
- gradually grows to compress pons and cause hydrocephalus
Most common presentation of acoustic neuroma?
Dx?
Tx?
Unilateral hearing loss= most common
- disequilibrium
- tinnitus
Dx: MRI w/ contrast
Tx: obs, surgical excision, radiotherapy
What is vertigo?
sense of motion when there is no motion
- spinning
- tumbling
- falling backward/forward
Key differences between central vertigo and peripheral vertigo (onset and sx)
Central: brain
- gradual onset
- no auditory sx (tinnitus)
Peripheral: balance organs of inner ear
- sudden onset
- severe enough so pt can’t walk or stand
- typically a/w N/V
- often a/w tinnitus
- often a/w hearing loss
- PE often seen horizontal nystagmus
Causes of central vs peripheral lesions
Central:
- brainstem vascular dz
- arteriovenous malformations
- tumors or brainstem or cerebellum
- MS
Peripheral:
- Meniere’s dz
- Labrynthitis
- Benign Paroxysmal Positional Vertigo
- Perilymphatic Fistula
Explain the Dix-Hallpike maneuver
How do you perform it and what results indicated positive?
quickly lowering pt to supine position w/ head extending over edge and placed 30 degrees lower than the body, turned to L or R
Positive test= delayed onset fatiguable nystagmus in peripheral causes
If nystagmus is non fatiguable, indicated central cause
What is the most common vestibular disorder?
Benign paroxysmal positional vertigo (BPPV)
Cause of Benign paroxysmal positional vertigo? Sx duration/onset?
-caused by sediment in inner ear (otoconia, otoliths)
- sx last less than a few mins
- appear in clusters lasting several days
- brief latency period following head movement before sx occur
- a/w changes in head position- rolling over in bed
Tx of BPPV?
PT or OT
Epley maneuver
Meds- vestibular suppressants
bed rest
