Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Introduction ++ Two categories based on whether observer can hear the tinnitus (objective) or not (subjective). ++ Objective—much less common than subjective Vascular—typically corresponds to pulse (aka, pulse synchronous tinnitus); may be venous, arterial, or combination (arteriovenous) source or secondary to high-output cardiac state, tumors, other; (pulse synchronous tinnitus may be subjective also) Pathogenesis: – Venous sources Jugular bulb: high riding and large, turbulent flow, dehiscent jugular plate at level of middle ear Sigmoid sinus: diverticulum, turbulent flow, dehiscent sigmoid plate Other venous structures: aberrant condylar vein, superior petrosal sinus, inferior petrosal sinus; aberrant vein contacting labyrinthine structures – Arterial sources Carotid artery: cervical carotid dissection, aneurysm, or stenosis; aberrant carotid artery; carotid body tumor; dehiscent carotid plate within the middle ear Persistent stapedial artery: derived from internal carotid artery, passes through obturator foramen of stapes superstructure – Arteriovenous (AV) malformations and dural AV fistulas May be associated with venous drainage leading to enlarged cortical veins (high rate of bleeding) Often associated with sigmoid/transverse sinus and prior craniotomy – Tumors Paraganglioma, middle ear adenoma, choristoma, facial nerve neuroma, hemangioma Any tumor (or encephalocele) contacting the ossicular chain or TM may lead to pulse synchronous tinnitus (subjective or objective) – High cardiac output states: anemia, thyrotoxicosis, pregnancy, beriberi, etc. Diagnosis: Auscultation with stethoscope, Toynbee tube, palpation of peri-auricular tissue – CT angiography – Magnetic resonance angiography (MRA)/magnetic resonance venography (MRV) – Formal cerebral angiography (small risk of stroke) Treatment: based on etiology and severity of symptoms – Selective embolization, surgical resection/clipping, and radiosurgery are options for dural AV fistulas and malformations. – Surgical excision or combination of surgery and radiosurgery may be used for tumors. – High output states should be medically corrected. – Anatomic vascular abnormalities may or may not be amenable to intervention. Nonvascular—typically presents as clicking sensation Palatal myoclonus—rapid (50-200 beats/min) irregular clicking caused by eustachian tube opening and closing from palatal musculature contraction. – Symptoms often worse during times of stress – Diagnosed by prolonged tympanogram showing movement with palatal contraction; may visualize palate with nasopharyngoscope as well; Toynbee tube may be used to auscultate rhythmic sound – Treated with muscle relaxants or botox in refractory cases – Often associated with central nervous system disease; MRI of posterior fossa should be performed to assess Stapedial or tensor tympani muscle spasm – Can be heard as clicking or crackling noise – Diagnosis similar to above, but without observed palatal muscle contractions – Treated with muscle relaxants or sectioning of tendons if refractory Patulous eustachian tube—symptoms worsen with respiration and are often described as roaring sensation; autophony – Can be diagnosed by TM movement with respiration, but not always visualized. Prolonged tympanometry may also be helpful – Placement of head in dependent position for relief of symptoms May be associated with temporomandibular joint disorders, normal swallowing that leads to TM movement (latter may be heard as single click with Toynbee tube) Subjective Incidence: 10% of population Can arise due to ... Your Access profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free a profile for additional features.