What lab finding is commonly seen in patients with otosclerosis?

In patients with otosclerosis, a common lab finding is decreased air conduction compared to bone conduction. This is indicative of a conductive hearing loss typically seen in this condition. Otosclerosis involves abnormal bone remodeling in the middle ear, particularly affecting the stapes bone, leading to its fixation. As a result, sound waves have more difficulty traveling through the air to the inner ear, resulting in poorer air conduction as compared to bone conduction.

When evaluating a person with otosclerosis using audiometry, you would observe that while bone conduction remains relatively normal (or even preserved), air conduction thresholds are elevated, indicating that the patient's ability to hear through the air is compromised compared to how well they hear through bone conduction. This pattern is critical for diagnosing conductive hearing loss associated with otosclerosis.

The other options do not accurately represent the typical findings in otosclerosis. Normal tympanic membrane mobility would not typically be seen because otosclerosis affects the ossicular chain rather than the tympanic membrane itself. Although an increase in auditory threshold can be indirectly inferred by the conductive hearing loss, it does not directly summarize the specific lab finding characteristic of otosclerosis. Lastly, elevated serum calcium levels are not a common finding in otosclerosis and are more associated with