Superior Canal Dehiscence

Superior Canal Dehiscence is when the bony cap over the superior semicircular canal has eroded away and the tough covering (dura) that protects the temporal lobe can make contact with the inner membranes of this canal causing disequilibrium.

Overview of Superior Canal Dehiscence

The superior semicircular canal has a bony cap over it that is sometimes very thin. This cap can be nonexistent in focal areas of the superior semicircular canal. In this situation, the tough covering (dura) that protects the temporal lobe can make contact with the inner membranes of this canal.

A small area of the bony covering of the superior semicircular canal is eroded and is exposed to the dura (shown in blue), which is the tough covering of the brain.