superior semicircular canal dehiscence (SSCD)

definition of SSCD

common symptoms of SSCD

common signs of SSCD

1. Physical exam of the ears (otoscopy) - often normal, but occasionally an SSCD patient can also have a more common condition like otitis media with effusion or eustachian tube dysfunction.

2. Tuning forks - even with an "normal" hearing test a 512Hz tuning fork may lateralize to the affected ear if the patient has a one-sided SSCD.

3. Vestibular exam - patients with SSCD may have subjective and/or objective findings - there is variability among subjects.

Dix Hallpike - normal unless the patient also has the more common BPPV

Frenzel goggles (or VNG testing) - tragal compression or pneumatic otoscopy - causes eye movements in the plane of the superior canal and dizziness (Hennebert sign). Valsalva against pinched nostril or closed glottis also can cause nystagmus. Finally, an audiometer fitted to the patient during examination of eye movements can show nystagmus to low frequency, high intensity sounds (although we have had one patient who was sensitive to 2KHz, but not 250 or 500Hz which is more commonly seen in SSCD cases)

how can you test for SSCD?

management options in SSCD

surgical repair of SSCD

Case 1 - 27 year old woman with left SSCD (video)

Case 2 - 39 year old woman with left SSCD (video)

Case 3 - 48 year old man with left SSCD and meningoencephalocele

Case 4 - 38 year old man with left SSCD (3D-temporal bone model)