Chapter 34 - Tinnitus Flashcards
Percentage of people with tinnitus
15%
Hypothesized reason for tinnitus
change in peripheral auditory function –> central neural hyperexcitability, cortex reorganization
Percentage of tinnitus pts w/ NL hearing on audiogram
10%
2 potential causes of pulsatile tinnitus
vascular malformation
neoplasm
Causes of clicking tinnitus
Mandibular condyle (TMJ) palatal or stapedial myoclonus
Type of HL associated with tinnitus caused by high dose salicylates
reversible mild to moderate SNHL (flat)
somatosounds
objective tinnitus, may be audible to examiner
myoclonus of tensor tympani
pulsatile variation in vessels near ear
phantom limb concept of tinnitus
In animal studies, auditory cortex reorganizes after sensory deprivation similar to how somatosensory cortex reorganizes after amputation
Vascular tinnitus
glomus tumor
dehiscent jug bulb, ICA
AVMs between occipital a (medial to mastoid) and transverse sinus
loop compressing CN VIII
Venous hum tinnitus - causes
Impingement of jugular vein by C2
High output heart (anemia, exercise, pregnancy, thyrotoxicosis)
Causes of pulsatile tinnitus other than vascular
otitis media otosclerosis Paget disease IIH MS
EAC pathologies causing tinnitus
cerumen
foreign body
hair, insect, other small objects
Muscles involved in palatal myoclonus
TVP, LVP, salpingopharyng, superior constrictor
How to evaluate palatal myoclonus
Nasopharyngoscopy, as opening mouth wide could cause the myoclonus to stop
Systemic diseases causing tinnitus
MS, stroke, tumor, trauma, syphilis, malaria, psychogenic, other degenerative processes
Objective findings in patients with tinnitus and normal audiometric thresholds
smaller wave I ABR amplitude
suggests early cochlear damage –> reduced neuronal input
Can noise exposure lead to tinnitus
Isolated loud noise tinnitus resolved in hours to days
Repeated episodes –> may be permanent
Relationship between tinnitus and hyperacusis
May be same central cause (decreased cochlear input)
Almost all hyperacusis pts eventually develop tinnitus
How to salicylates cause hearing loss
competitive inhibitors of chloride at anion binding site of prestin (motor protein of outer hair cell) –> reversible alteration of outer hair cell function
Reverse within 1-3 days of d/c
List of drugs causing tinnitus
ACEi, anesthetics (lidocaine, bupivacaine, dyclonine), aminoglycosides, imipenem, Vanc, bactrim, aztreonam, erythromycin, cipro, antidepressants, phenergan, sudafed, anti-malarials, B blockers, CCB, diuretics, NSAIDs, sedatives
Misc: albuteraol, carbamazepine, flexeril, cyclosporine, benadryl, flecainide, isotretinoin, lithium, methergine, nicorette, prazosin, omperazole, Hep B vaccine, sodium nitroprusside, tocainide
Percent of acoustic neuromas with tinnitus
10% present this way
80% eventually have it
Treatment of tinnitus with auditory stimulation
fan, radio, generator, TV
Hearing aid (if frequency in amplification range)
custom devices
Tinnitus retraining therapy
Counseling to educate on cause of tinnitus, decouple tinnitus from emotional response
Sound therapy to gradually habituate and thus reduce strength of tinnitus
Meds for tinnitus
None better than placebo
Can treat stress/anxiety accompanying it with TCA, SSRI, benzo
Botox for myoclonus
How IV lidocaine stops tinnitus
augments natural central inhibition of auditory firing (which may be lost and then cause tinnitus, one theory)
Transcranial magnetic stimulation for tinnitus
low level electric brain currents which inhibit hyperexcited regions of brain
Treatment of tinnitus associated with bilateral profound HL
CI - cures tinnitus in 86% of cases
Treatment of myoclonus tinnitus
botox
tympanostomy tubes
