Dizziness and Hearing Loss
Tinnitus
Definition
Any abnormal sound arising within head, perceived in one or both ears, or inside head. Continuous, intermittent, or pulsatile.
Objective Tinnitus
Heard by examiner as well as patient. Uncommon, but associated with serious conditions that mandate prompt diagnosis.
Etiology
Intravascular turbulence: aortic or carotid stenosis, arteriovenous malformations of head and neck, vascular tumors (e.g., glomus jugulare); aneurysms of abdomen, chest, head, neck; enlargement of sigmoid sinus and jugular vein; high blood pressure (typically pulsatile tinnitus); temporal arteritis.
Other causes: temporomandibular joint syndrome; palatal myoclonus.
Evaluation
Auscultation of ear, head, and neck indicated in all patients with tinnitus. Blood pressure, fundoscopic examination especially for pulsatile tinnitus.
Subjective Tinnitus
Abnormality somewhere in auditory system from external ear to central auditory connections.
Etiology
Chronic exposure to loud noise; acoustic neuroma (often years before hearing loss or ataxia); compression or inflammation of vestibulocochlear nerve; otosclerosis; otitis; cerumen.
Evaluation
Otologic consultation, hearing tests for persistent tinnitus. Also consider auditory evoked potentials, MRI.
Hearing Loss
Conductive Hearing Loss
Due to decreased mechanical transmission of sound waves in external or middle ear.
Etiology
Trauma, congenital cranial abnormalities, otosclerosis, ossicular discontinuity (trauma or erosion from chronic otitis media).
Evaluation
Patients speak with soft or normal voice because own voice sounds louder than background sounds in environment. In tuning fork test, sound conveyed by bone conduction is as loud as or louder than by air conduction (abnormal Rinné test). Sound of tuning fork in midline of forehead (Weber test) heard as though it originated on side of hearing loss. Audiometry, middle ear impedance test confirm diagnosis.
Treatment
Hearing aids, reconstructive microsurgery.
Sensorineural Hearing Loss
Due to decreased transmission of signals in auditory nerve or central auditory pathways. Most often with lesion in cochlea or cochlear nerve. Rarely from central auditory dysfunction.
Etiology
Excessive exposure to noise, ototoxic drugs, age-related cochlear degeneration, congenital cochlear defects, viral or bacterial infections.
Evaluation
Patients speak with loud voice. Air conduction greater than bone conduction (normal Rinné). Tuning fork louder in better ear on Weber test. Difficulty hearing words suggests central lesion. Audiometry, auditory evoked potentials for lesion
localization. MRI of the brain and internal auditory canals with and without gadolinium for any asymmetric sensorineural hearing loss (possible cerebellopontine angle tumor).
localization. MRI of the brain and internal auditory canals with and without gadolinium for any asymmetric sensorineural hearing loss (possible cerebellopontine angle tumor).
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