Superior Semi-Circular Canal Dehiscence

Superior Semi-circular Canal Dehiscence Syndrome (SSCD) is a very rare medical condition where a thinning or complete absence of a portion of the temporal bone overlying the superior semicircular canal of the inner ear causes hypersensitivity to sound and balance disorders. For unclear reasons, bone of the skull base slowly dissolves exposing the superior balance canal. This allows sound to “escape” from the inner ear resulting in hearing loss.  Computed Tomographic scanning (CT) and Magnetic Resonance Imaging (MRI) may be used to diagnose SSCD, and distinguish it from more common diseases with similar symptoms such as Meniere’s disease.

Symptoms of SSCD include dizziness and balance problems which increases with activity and which is relieved by rest. A cardinal symptom of this disorder is vertigo produced with a loud sound. Other symptoms may include hearing loss, tinnitus and a fullness of the ear. The symptoms of SSCD can get worse with extended episodes of coughing, sneezing, or blowing of the nose. Sometimes the use of ones’ own voice or a musical instrument can also aggravate SSCD.


A specialized CT scan of the ear is needed to accurately diagnose the condition. Once the condition has been diagnosed, surgery may be an option in order to repair the defect in the superior semi-circular canal, and relieve patients of their hearing and balance symptoms.  There is no effective medical management of this condition.