Could vestibular evoked myogenic potentials (VEMPs) also be useful in the diagnosis of perilymphatic fistula?

The role of vestibular evoked myogenic potentials (VEMPs) is at this time indisputable in the study of vestibular disorders. Furthermore, VEMPs are widely accepted as a diagnostic tool when a superior semicircular canal dehiscence (SCD) is suspected, presenting in such cases a lowering of threshold values able to raise a recordable response due to increased inner ear immittance. According to the same principle, the possibility of another kind of alteration having the same effect on the inner ear might be considered when high-resolution computed tomography has excluded the presence of an SCD. In this paper four cases are described in which high-resolution computed tomography showed normal features without any labyrinthine dehiscence and VEMP threshold values were lowered; the appropriateness of suspecting a perilymphatic fistula in such cases and resorting to VEMPs in detecting a perilymphatic fistula is discussed.