Superior Semicircular Canal Dehiscence Syndrome (SSCDS, SCDS)

 

Synonym: superior canal deshiscence syndrome (SCDS)

 

Clinical findings:

(1) vertigo and/or nystagmus triggered by a sound or noise (Tullio phenomenon)

(2) autophony (abnormal amplification of sounds such as own voice, breathing, etc)

(3) vertigo and/or nystgamus triggered by pressure in the external auditory canal (Hennebert’s sign)

 

Some triggers for vertigo and/or nystagmus have included:

(1) cough

(2) Valsalva maneuver

(3) tragal compression

(4) straining at stool

(5) increased intracranial pressure

 

Analysis of the nystagmus shows that the rotation axes align with the affected superior semicircular canal.

 

A high-resolution CT scan of the inner ear confirms the diagnosis.