Hearing one’s own breathing or eyes moving…Dizziness with exertion or straining… A full or blocked feeling in the ear…hearing loss. An unusual group of symptoms can accompany an unusual disease. Superior semicircular canal dehiscence is the name given to a disorder in which the normal dense bony covering of one of the three canals in the inner ear is thinned or missing.
This disorder can cause a number of very strange symptoms to occur. Many patients with this condition are asymptomatic or may just feel a full feeling in the ear. Others may have a full constellation of symptoms that include hearing one’s breathing, pulse, or other sounds in the ear, as well as vertigo with loud sounds in the ear or visual disturbances with hearing loud sounds or doing straining or exertional activity. Patients often hear internal sounds in the body at an abnormal level through bone conduction, and can have changes in hearing levels of varying types.
This condition is typically diagnosed with a history and physical examination, a CT scan of the inner ear, and an electrophysiological test called a cervical VEMP. This test involves presenting sounds to the ear and measuring muscular changes in the large neck muscle that runs from the upper sternum to the ear called the sternocleidomastoid muscle. When patients have this condition, the fluid mechanics in the inner ear are abnormal and this results in sounds and pressure in the ear causing abnormal stimulation of the balance system.
In many patients, this condition does not require treatment. Particularly if a patient has limited symptoms, such as a full feeling in the ear or mild hearing loss, it may be decided to simply monitor the condition. In other patients, symptoms may be so severe as to require medication to limit symptoms or surgery to treat the abnormal inner ear canal. Patients with significant balance issues may require a team approach with balance therapy with a physical therapist.
There are several procedures that have been used for this condition. The most commonly used procedure is a resurfacing or plugging procedure to correct the bony weakness in the balance canal. This is done through either an incision above the ear or behind the ear. In selected cases, a procedure can be done through the ear canal in which the inner ear is reinforced.