May destroy ossicles or erode into surrounding structures Often history of previous perforations or chronic infections Trapped stratified squamous epithelial mass in middle ear. Often associated with pain ± feverĪntibiotics (unless viral cause suspected), decongestants, pain control Pus (or fluid) in middle ear dampens conduction through ossiclesĪcute to subacute onset, often following URI. Bubbles can cause intermittent painĭecongestants. ENT referralįluid in middle ear dampens conduction through ossicles Counsel on importance of keeping water out of ear canal. May have sudden relief from pain if caused by otitis media May follow direct trauma or sudden barotrauma. Slow onset following perforations, trauma, or infectionsĭisruption of TM integrity results in impaired transmission of sound to ossicleĪcute onset. Decreased mobility impairs sound conduction TM scarring from perforations or infections. No pain or drainage unless causes complete obstructionĮvaluate for infection.
Often seen with prolonged exposure to cold water (divers) Evaluate for necrotizing otitisīony growths obstruct canal. Drainage, odor often presentĪural toilet to remove debris. Evaluate for TM perforationĮdema and detritus obstruct external canal Mass in external canal blocks sound conductionĪcute onset associated or not with pain, drainage, or odor Lack of hearing either bone or air conduction points to sensorineural hearing loss ( Table E2). Perception of sound better through bone conduction indicates a conductive deficit. Normally functioning ears hear the air conduction louder and longer than the bone conduction. The vibrating end is then held near the ear canal. The handle of a vibrating fork is placed on the mastoid process of the side being evaluated. Normally, air conduction is more sensitive than bone conduction, and one should be able to hear a vibrating fork longer through the air than through bone. The Rinne test evaluates each ear independently ( Fig. If the fork is heard louder in one ear, either that ear has a conductive deficit or the other ear has a neural deficit ( Table E2). The patient is asked which ear hears the vibrations better. A vibrating fork is placed midline on the top of the head. The Weber test compares the two ears with each other ( Fig. Tuning fork tests provide the best clues to distinguish between conductive and sensorineural hearing loss. The history must include details about the timing of hearing loss, laterality, previous episodes, associated symptoms (tinnitus, vertigo, or pain), preceding events (diving, plane rides, trauma), potential placement of a foreign body, environmental noise exposure, and potential ototoxic drugs. The first step in evaluating hearing complaints is to ascertain the location and extent of the hearing loss. The Rinne and Weber tests are then carried out as indicated, using the silent tuning fork.
To test the reliability of the patient's responses, it is occasionally useful to strike the tuning fork against the palm of the hand and hold it briefly to silence it. In patients with unilateral sensorineural deafness, the sound is not heard on the affected side but is heard by, or localized to, the unaffected ear. Thus, the affected ear hears and feels the vibrating tuning fork better than does the normal ear. In an ear with a conductive hearing loss, the AC is decreased, and the masking effect is therefore diminished. This tends to mask the sound of the tuning fork heard by BC. In normal conditions, there is considerable background noise, which reaches the tympanic membrane by AC. The explanation for the Weber test effect is based on the masking effect of background noise. You have created a conductive hearing loss on the right by blocking the right canal the sound is lateralized to the right side. Occlude your right ear and place a vibrating tuning fork in the center of your forehead. Sound is lateralized to the affected side in conductive deafness. If the sound is not heard in the middle, the sound is said to be lateralized, and thus a hearing loss is present. Hearing the sound, or feeling the vibration, in the middle is the normal response. Ask the patient to indicate whether he or she hears or feels the sound in the right ear, in the left ear, or in the middle of the forehead. Stand in front of the patient and place a vibrating 512-Hz tuning fork firmly against the center of the patient's forehead. In the Weber test, BC is compared in both ears, and the examiner determines whether monaural impairment is neural or conductive in origin. Swartz MD, FACP, in Textbook of Physical Diagnosis: History and Examination, 2021 The Weber test
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