Several theories have been proposed regarding the cause of SCD, including

• embryological—a postnatal failure of bone formation over the superior semicircular canal due to a malpositioned primitive otocyst
• bone thinning associated with aging and/or vascular malformations
• head trauma, typically to the temporal bone
• surgical complication following surgical removal of the bone over the superior canal, usually in an attempt to “blue line” the labyrinth
• increased intracranial pressure resulting from activities such as straining, sneezing or coughing in already thinned bone