Table 1.

Proposed diagnostic criteria for superior canal dehiscence syndrome (SCDS).

Patients should meet the following conditions: 1.High-resolution computed tomography images (≤0.625-mm slice thickness) reformatted in the plane of the superior SCC demonstrating a dehiscence 2.At least one of the following symptoms consistent with SCDS A.Bone conduction hyperacusis (in the form of autophony, audible eye movements, audible footsteps, etc.) B.Sound-induced vertigo C.Pressure-induced vertigo (via nasal or glottic Valsalva or pressure applied to the external auditory canal) D.Pulsatile tinnitus 3.At least one of the following diagnostic tests indicating a third mobile window A.Negative bone conduction thresholds on pure tone audiometry B.Enhanced VEMP responses (low cervical VEMP thresholds or high ocular VEMP amplitudes) C.Elevated summating potential to action potential ratio on electrocochleography in the absence of a sensorineural hearing loss

SCC, semicircular canal; VEMP, vestibular-evoked myogenic potential.

VEMP thresholds should be compared to laboratory norms.