VEMP and endolymphatic hydrops VEMP and endolymphatic hydrops

High resolution magnetic resonance imaging (MRI) and computed tomography (HR-CT) of the inner ear are becoming more important for the diagnosis of central and peripheral vestibular disorders. MRI is established as an essential modality in the imaging of the temporal bone, cerebello-pontine angle and posterior cranial fossa. It is used to evaluate normal anatomic structures, evaluate for inflammatory and/or infectious and/or neoplastic processes. Modern MRI techniques allow visualization of detailed anatomic features of the vestibulo-cochlear regions as well as pathologic findings in the inner ear causing vertigo. Nevertheless, despite the widespread use of MRI for these purposes, many radiologists remain unfamiliar with the complex anatomy and expected imaging findings with such examinations

Third window syndrome represents a group of symptoms that result from a pathological communication between the inner ear and the surrounding structures, these symptoms include auditory symptoms including bone conducted hyperacusis, autophony or pulsatile tinnitus, vestibular symptoms include sound or pressure induced vertigo or chronic imbalance.

The diagnosis of third mobile window syndrome depends on the presence of typical symptoms, specific VEMP or other findings in some audio vestibular tests, and it is confirmed by high resolution Temporal bone CT scan.

Superior semicircular canal dehiscence is the first and most commonly known type of third window disease, however other types were discovered later on, including posterior semicircular canal dehiscence, cochlear- facial nerve dehiscence, vestibular aqueduct- Jugular bulb dehiscence and enlarged vestibular aqueduct.

A new type of third window syndrome was discovered in our center, and to the best of our knowledge it was never been described in the literature, which is vestibular aqueduct dehiscence with hyperpneumonized air cells.

Surgical treatment of vestibular disorders