Semicircular canal dehiscence syndrome (SCD), affects balance and hearing. “Dehiscence” is another word for hole. If you have SCD, you have a hole or a thinning in the bone of one of the semi-circular canals. The semi-circular canals are part of the balance organ which is located inside your ear. This hole can cause problems with the way sounds come into the inner ear, and also with how your body balances itself.

Symptoms of Semi-Circular Canal Dehiscence

When you have SCD you might have one or more of the following:

• Echoes of sounds in your ear, like when you eat or talk (called autophony).

• Fullness in your ears.

• Hearing loss.

• A heightened ability to hear your own bodily movements (such as footsteps, eye movements, and brushing hair).

• Quick side to side, or up and down movements of your eyes (nystagmus).

• Ringing in the affected ear.

• Hearing the sound of your pulse in your ear.

• Unsteadiness.

• Vertigo or dizziness.

The symptoms of SCD can be triggered by:

• A cough or sneeze.

• Atmospheric pressure changes.

• Loud sounds.

• Lifting heavy objects.

• Straining.

Causes of Semi-Circular Canal Dehiscence

The semi-circular canals are three small looped structures inside the ear filled with fluid that moves when we move. When the fluid moves, tiny sensors (hair cells) inside the canals also move. These sensors tell the brain how our body is positioned in space. The brain takes that information and tells our muscles how to act to help you keep your balance. SCD affects how the sensors react to movement because the semicircular canal develops an abnormal communication with the inside of the skull.

Possible causes of SCD

• A gene passed down from your parents that kept the bone in that area from growing thick enough.

• An infectious disease.

• Some form of trauma that damaged the bone.