Conductive hearing loss
Alerts and Notices
SynopsisConductive hearing loss (CHL) is a form of hearing loss in which there is some degree of failure of sound energy transfer into the inner ear. This limits the ability for sound to be received by the cochlea and transmitted through the auditory pathways of the brain. Common causes of CHL include acute otitis media, impaction of the ear canal from cerumen or a foreign body, persistent / recurrent otitis media with effusion (OME), and perforation of the tympanic membrane (TM). More serious causes include tumor formation, such as cholesteatomas and nasopharyngeal tumors, or congenital aural atresia in children. Other causes include otosclerosis, an abnormal bone deposition in the middle ear leading to abnormal vibration of the stapes in the oval window, and myringosclerosis, which can develop from chronic infection. Calcium deposits can be visualized on the tympanic membrane in patients with myringosclerosis.
Patients of all ages can be affected by CHL. Younger patients are at higher risk due to the increased incidence of conditions such as OME. Approximately 1 in 5 children will develop OME by the age of 2 years. A history of chronic or untreated otitis media is one of the most common risk factors. Other factors include a family history for inherited conditions such as otosclerosis.
Symptoms vary depending on the cause and severity of the underlying condition. The hearing loss can be sudden or gradually appear over time. Common symptoms include muffled hearing, a full sensation of the ear, ear pain, ear drainage, and possibly dizziness.
H90.2 – Conductive hearing loss, unspecified
44057004 – Conductive hearing loss
Differential Diagnosis & Pitfalls
- Sensorineural hearing loss – Weber and Rinne tests can aid in differentiating this from CHL.
- Postnasal space tumors – Nasal discharge and weight loss are seen. This is more likely in older patients.
- Cerumen / foreign body obstruction – Otoscopic examination can rule out this as a cause of hearing loss.
- OME – Look for poor movement of the TM with pneumatic insufflation. TM will also appear dull and gray on examination.
- Cholesteatoma – Pearly white mass can be seen behind the TM.
- TM perforation – Blood can occasionally obstruct the ear canal and prevent visualization of the TM.
Conductive hearing loss