LecturePatient will present as → a 72-year-old male with a progressively worsening hearing loss. He states that his trouble with hearing began 7-8 years ago. He can hear when someone is speaking to him; however, he has difficulty understanding what is being said, especially when there is background noise. In addition to his current symptoms, he reports a steady ringing in both ears, and at times experiences dizziness. Medical history is significant for three prior episodes of acute otitis media. His family history is notable for his father being diagnosed with cholesteatoma. His temperature is 98.6°F (37°C), blood pressure is 138/88 mmHg, pulse is 14/min, and respirations are 13/min. On physical exam, when a tuning fork is placed in the middle of the patient's forehead, the sound is appreciated equally on both ears. When a tuning fork is placed by the external auditory canal and subsequently on the mastoid process, air conduction is greater than bone conduction. (presbycusis)
To watch this and all of Joe Gilboy PA-C's video lessons you must be a member. Members can log in here or join now.
The most common causes of hearing impairment/loss are cerumen impaction, eustachian tube dysfunction (secondary to upper respiratory tract infection), and increasing age (presbycusis).
Hearing loss can be classified as conductive, sensorineural, or both (mixed loss)
- Conductive hearing loss occurs secondary to lesions in the external auditory canal, tympanic membrane (TM), or middle ear. These lesions prevent sound from being effectively conducted to the inner ear.
- Sensorineural hearing loss is caused by lesions of either the inner ear (sensory) or the auditory (8th) nerve (neural). This distinction is important because sensory hearing loss is sometimes reversible and is seldom life-threatening. A neural hearing loss is rarely recoverable and may be due to a potentially life-threatening brain tumor—commonly a cerebellopontine angle tumor.
- A mixed loss may be caused by severe head injury with or without fracture of the skull or temporal bone, by chronic infection, or by one of many genetic disorders. It may also occur when a transient conductive hearing loss, commonly due to otitis media, is superimposed on a sensorineural hearing loss.
Neurological deficits necessitate imaging
- Weber test: Tuning fork is placed on the center of the head and see if sound lateralizes - Sound lateralizes to affected ear in conductive hearing loss, Sound lateralizes to unaffected ear in sensorineural hearing loss
- Rinne test: Tuning fork placed on mastoid and then up to the ear (should continue to hear) conductive hearing loss if bone > air, sensorineural hearing loss if air > bone
The causes of hearing loss should be determined and treated
Question 1 |
Which of the following are normal findings in a Weber test?
The tympanic membrane is movable with pneumatic otoscopy Hint: A movable tympanic membrane indicates there is no effusion, and is not the Weber test. | |
The tympanic membrane is pearly gray with a sharp cone of light with apex at the umbo Hint: The tympanic membrane is evaluated by direct observation with an otoscope, and is not the Weber test. | |
Sound is heard equally in both ears when a vibrating tuning fork is placed on the mid forehead | |
Air conduction is greater than bone conduction when a vibrating tuning fork is moved from the mastoid bone to close to the ear canal Hint: A normal Rinne test means that tuning fork vibration is heard longer through the air than the bone. |
Question 1 Explanation:
A normal Weber test means there is no lateralization of sound perception when a vibrating tuning fork is placed on the mid forehead.
Question 2 |
A 45 year-old male complains of loss of hearing in his left ear. He also complains of ringing in the ear, and has had occasional dizziness. On exam, there is unilateral left- sided sensorineural hearing loss and a diminished corneal reflex. Neuro exam is otherwise normal. TMs are normal, and canals are clear. Neck is supple, without adenopathy. Oropharynx is normal. Of the following, the best diagnostic study to identify the cause of this patient's complaints is
auditory brainstem evoked response Hint: See B for explanation. | |
gadolinium-enhanced MRI | |
acoustic reflex testing Hint: See B for explanation. | |
vestibular testing Hint: Vestibular testing is not a useful screening test for acoustic neuromas. |
Question 2 Explanation:
MRI has replaced auditory brainstem evoked response and acoustic reflex testing in the evaluation of patients for acoustic neuromas.
Question 3 |
The most common cause of conductive hearing loss is
otosclerosis Hint: See C for explanation. | |
cholesteatoma Hint: See C for explanation. | |
impacted cerumen | |
chronic serous otitis media Hint: See C for explanation. |
Question 3 Explanation:
The most common cause of conductive hearing loss is impacted cerumen.
Question 4 |
A 2 month-old infant presents for a routine health maintenance visit. The mother has been concerned about the infant's hearing since birth. Physical examination reveals no apparent response to a sudden loud sound. Which of the following is the most appropriate diagnostic evaluation?
audiometry Hint: Pure tone audiometry can be used to screen for hearing deficits in children over the age of 3 years. | |
tympanometry Hint: Tympanometry is used to identify an effusion as the cause of hearing loss, but in infants over the age of months. | |
acoustic reflectometry Hint: Acoustic reflectometry measures the spectral gradient of the tympanic membrane, but is not used clinically due to concerns about its reliability. | |
auditory-evoked potentials |
Question 4 Explanation:
Brainstem auditory-evoked potentials evaluate the sensory pathway and identify the site of any anatomical disruption. The test does not require any active response from the patient and is useful in the evaluation of suspected hearing loss in an infant.
Question 5 |
Whispered voice test on a patient reveals decreased hearing in the left ear. Which of the following would be most consistent with conductive hearing loss in the left ear?
Sounds best heard in the left ear on Weber test. | |
Air conduction longer than bone conduction in the left ear on Rinne test. Hint: With conductive hearing loss, bone conduction should be heard as long as or longer than air conduction of sound in the effected ear. Air conduction lasting longer than bone conduction of sound would indicate sensorineural hearing loss. | |
Sound best heard in the right ear on Weber test. Hint: Sound best heard in the ear with unaffected hearing on Weber test (in this case, the right ear) is indicative of sensorineural hearing loss. | |
Bone conduction longer than air conduction in the right ear. Hint: With conductive hearing loss, bone conduction should be heard as long as or longer than air conduction of sound in the affected ear. The right ear showed normal hearing on physical exam. |
Question 5 Explanation:
Sound best heard in the ear with decreased hearing on Weber test (in this case, the left ear) is indicative of conductive hearing loss.
Question 6 |
When performing a Weber test on a patient with impacted cerumen in the right canal, the sound should be
referred to the right ear | |
referred to the left ear Hint: See A for explanation. | |
equal in both ears Hint: See A for explanation. | |
louder with air conduction Hint: Bone conduction as noted with the Rinne test is louder than air with conductive hearing loss. |
Question 6 Explanation:
In unilateral conductive hearing loss, the sound is referred to the impaired ear.
Question 7 |
A patient presents complaining of gradual hearing loss over the past 3 months. He admits to use of Q-tips and otherwise does not wear ear plugs or place other foreign objects in his ear. On examination external auditory canals are obstructed with cerumen. After removal of cerumen, hearing is equal on both sides. Appropriate counseling of this patient includes which of the following?
Advise him to discontinue use of cotton swabs | |
Encourage jet irrigator (i.e. WaterPik) to clean ears Hint: Use of jet irrigators designed for cleaning teeth (i.e. waterPik) for wax removal should be avoided since they may result in tympanic membrane perforations. | |
Instruct in ear irrigation with cold water Hint: Irrigation is performed with water at body temperature to avoid a vestibular caloric response. | |
Refer to dermatologist Hint: See A for explanation. |
Question 7 Explanation:
In most people, the ear canal is self-cleansing. In most cases, cerumen impaction is self-induced through ill- advised attempts at cleaning the ear.
There are 7 questions to complete.
|
List |
References: Merck Manual · UpToDate