Otoscopic Examination

The tympanic membrane is inspected with an otoscope and indirect palpation with a pneumatic otoscope. With the right hand holding the otoscope in a pen-like fashion, and the other hand braced against the patient’s face, the largest speculum usable (normally 5 mm for adults) is gently guided down into the canal and forward. The distal portion of the canal contains thin, sensitive skin, and produces pain when pressure is applied.

Straighten the external auditory canal by pulling the pinna (in an adult) backwards and upwards, or (in a child) backwards and downwards.
Examine for discharge, inflammation, or foreign bodies.
The position and color of the membrane, and any unusual markings, deviations, (and in the middle ear, through the semi-transparent tympanum) fluid, air bubbles, blood, or masses are all noted.
Obstruction by cerumen calls for cerumen removal through various methods discussed under cerumen impaction. However, small amounts are normal and should not be interfered with.
The healthy tympanic membrane is pearly gray and positioned obliquely at the base of the canal.

Audiometry

The single most important test for detecting hearing loss; also known as audiography or an audiogram. It tests a person’s ability to hear various sound frequencies and measures hearing acuity. It uses an audiometer used by an audiologist, a trained technician. There are two types of audiometry: Pure-Tone Audiometry, which plays a single tone played quietly and increased in volume until heard by the patient, and Speech Audiometry, where spoken words are used to determine the ability to hear and discriminate sounds and words.

No special precautions required. The patient sits in a soundproof chamber or cubicle, puts on headphones, and signals to the examiner when they can hear the stimulus. Conductive hearing is measured by tones directed over the external auditory canal, and nerve conduction is measured by tones directed onto the mastoid bone.
Otoscopy may be done prior to audiometry testing to determine if any blockages are present (foreign body, cerumen).
Normal hearing in adults can detect sounds from 20 to 20,000 Hz in frequency (Speech Frequencies span from 500 to 2,000 Hz) played as softly as 0 to 20 dB, and speech from 20 to 50 dB in volume. Anything over 80 dB may be perceived as harsh and injurious to the inner ear.
The important level of loudness is ~30 dB, within the speech frequencies (500 to 3,000 Hz), and it is the goal of hearing-improvement surgery.
Inability to hear pure tones below 25 dB indicate some extent of hearing loss.

Loss in dB	Interpretation
0-15	Normal Hearing
15-25	Slight hearing loss
25-40	Mild hearing loss
40-55	Moderate hearing loss
55-70	Moderate to severe hearing loss
70-90	Severe hearing loss
>90	Profound hearing loss

Tympanometry

A test to check the condition and mobility of the ear drum, to detect disorders of the middle ear. It is an otoscopic exam that varies the air pressure in a sealed ear canal, and measures the ear muscle reflex responses to the pressure changes.

Inform the patient to avoid speaking, moving, swallowing, or being startled (especially by the loud noises during examination), as these alter middle ear pressure and may invalidate test results.

Brain Stem Auditory Evoked Response (BAER)

Also known as Auditory Brain Stem Response (ABR) Audiometry. This test helps diagnose nervous system abnormalities, hearing losses (especially in LBW newborns), and to assess neurologic functions. Brain waves are stimulated in response to a clicking sound, which is used to evaluate the central auditory pathways of the brainstem.

Patients may be asked to wash their hair the night before the test. Do not apply any additional products.
Electrodes are placed on the patient’s scalp and on each earlobe, then acoustic stimuli (e.g. clicks) are made in the ear. Resultant electro-physiologic measurements can determine when the patient is able to hear (in dB) the stimuli, and any impairments along the nerve pathways (e.g., a tumor on the vestibulocochlear nerve).

Electronystagmography (ENG)

A vestibular test that evaluates electric potentials created by spontaneous, positional, or calorically evoked nystagmus. These record the electrical fields that occur with movements of the eye (the patient is instructed to follow a moving target; eye movements are monitored while the head is placed in different directions), and is used to determine causes of unilateral hearing loss, vertigo, or tinnitus.

Damage to the nerve of the inner ear is one of the more common causes of vertigo.
All vestibular suppressants (alcohol, caffeine, etc.) are withheld 48 hours before the exam. Anti-dizziness, anti-depressant, anti-histamine, tranquilizing, or sedative drugs or narcotics of any type are stopped 5 days prior to the balance test. These including codeine and medications containing codeine.
Do not eat for 3 hours before the examination.
Do not use facial creams or make up, as they may interfere with accurate recording during the test.
Someone must accompany the patient to the test to drive them home, as dizziness is induced.
The Caloric Test may be used to induce nystagmus. It involves stimulating the inner ear with temperature changes in order to test the nystagmus response. Warm or cold water or air is circulated in the ear canal. A normal response follows the COWS mnemonic: Cold, Opposite; Warm, Same side. The nystagmus moves contralateral to the instillation in cold water, and moves ipsilateral to the instillation if warm water is used. This movement is known as the vestibulo-ocular reflex.

Platform Posturography

For those with dizziness and balance disorders. This exam can determine if vertigo is worsening, or responding to treatment. The integration of visual, vestibular, and proprioceptive cues with motor response output and coordination of the lower limbs is tested. A platform is surrounded by screens. The screens may move, or the platform may move. These assess which systems related to balance are impaired.

Preparation is the same as the alcohol, caffeine (48 hours), and medication (5 days) restrictions in electronystagmography.

Sinusoidal Harmonic Acceleration

A rotary chair is used to assess the vestibulo-ocular system by analyzing compensatory eye movements in response to the rotation of the chair. This may help identify unilateral disease, and evaluate the course of recovery, but it is not able to identify the side of the lesion.

Preparation is the same as in platform posturography.

Middle Ear Endoscopy

Endoscopes with small diameters and acute angles can be used by an endoscopist with an otolaryngology specialization to examine the middle ear. It may be used for evaluating suspected perilymphatic fistula and new onset conductive hearing loss, the anatomy of the round window prior to transtympanic treatment for Meniere’s Syndrome (Endolymphatic Hydrops), and the tympanic cavity before ear surgery to treat chronic middle ear and mastoid infections.

The external auditory canal is irrigated with sterile NSS, and the tympanum anesthetized. A microscope-assisted laser (or myringotomy knife) tympanectomy is done, where the endoscope is inserted.%%

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Diagnostic Examination of the Ear