What is superior canal dehiscence?

Superior canal dehiscence is an opening (dehiscence) in the bone that covers the superior semicircular canal of the inner ear. It can result in symptoms that affect a person's balance and hearing.

What are the symptoms of superior canal dehiscence?

Symptoms of superior canal dehiscence can include vertigo (dizziness), oscillopsia (appearance of movement of stationary objects), autophony (hearing one's voice or self-generated sounds such as breathing or blinking louder than normal, sensitivity to loud sounds, and fullness/pressure in the ears.

The vertigo and oscillopsia commonly associated with superior canal dehiscence can be triggered by common activities that change the pressure in the brain or the middle ear. These activities include straining, coughing, sneezing, heavy lifting, exercising, and listening to loud noises.

What causes superior canal dehiscence?

The dehiscence can be congenital (present from birth) and may have occurred during the development of the inner ear. It can also be caused from certain infections as well as head trauma.

It is estimated that approximately 1 to 2% of the general population has abnormally thin bone covering their superior semicircular canal. The average age for diagnosis of superior canal dehiscence is approximately 45 years old. Approximately 33% of patients diagnosed will have superior canal dehiscence in each ear.