Het 'superior-canal dehiscence'-syndroom

- Superior-canal dehiscence syndrome (SCDS) was first described in 1998; it manifests as symptoms of dizziness and oscillopsia when a sound or pressure stimulus is given to the ear concerned.

- SCDS is caused by dehiscence of petrosal bone overlying the superior, vertical semicircular canal, creating a ‘third mobile window’ to the labyrinth, in addition to the oval and round windows.

- Characteristic for this syndrome are eye movements with a vertical-torsion direction, evoked by sound stimuli, or pressure changes via the external ear canal and the Valsalva manoeuvre.

- The anomaly of the bony structure is visible on a CT scan.

- With its specific symptoms and characteristics, SCDS is an abnormality of the vestibular system that is relatively easy to diagnose.

- The syndrome may be treated with conservative or surgical means.

Ned Tijdschr Geneeskd 2005;149:1320-5