Superior Semi Circular Canal Dehissence

SSCCD (Minor’s Syndrome/Described by Lloyd Minor in 1998 at Hopkins)
Basically acts like a 3rd window and dissipates the sound energy. (3rd Mobile window syndrome)
Clinically with vertigo (Tullios Phenom–vertigo with noise) (Hennebert’s Sign(Positive Fistula Test)–vertigo with pneumatic otoscopy positive pressure)–Eyes move in the plane of the semi circular canal (Ewald’s Law)

Oscillopsia

Hearing loss, autophony of voice with no autophony of breathing (unlike patulous ETT), many patients complain they can hear bodily functions.  Can hear their eyes moving or other functions because of supraphysiologic bone thresholds (need to specifically test for these less than zero decibel thresholds)

See on a thin cut (0.5MM)CT (actually overly sensitive)—If it is negative it is negative, if it is positive may be a false positive.  Can find in 2-10% of the general population.

Have hearing loss (inner ear conductive loss)—many failed Stapedectomies have been tried. (Acoustic Reflexes are intact)–if they have a true conductive loss the acoustic reflexes should be absent).

VEMPS–Lower threshold on C-VEMPS (cervical VEMPS) than controls.  Ocular VEMPS are even more sensitive.

May be what we thought previously to be a PLF which is why Round window reinforcement works.

SSCDS

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