Differential Contribution of Vestibular Evoked Myogenic Potentials for Diagnosis of Superior Semicircular Canal Dehiscence Syndrome

Introduction: Superior semicircular canal dehiscence syndrome (SSCDS) is described as a disorder of the inner ear denoted by the absence of a bony covering, causing vestibular and auditory symptomatology.The vestibular evoked myogenic potentials (VEMPs) provide information regarding the vestibular function, which is useful in the diagnosis of vestibular disorders.Our aim is to assess the differential role of ocular VEMP (oVEMP) and cervical VEMP (cVEMP).Methods: oVEMPs and cVEMPs were collected from four male and five female (64.5 ± 3.6 years old) with SSCDS validated by computerized axial tomography between 2017 and 2019.The neurophysiological assessment included the calculation of latency and amplitude of both the pathological ear (PE) and the healthy ear (HE) and the asymmetry ratio (AR) of both ears.A control group comprising 14 people without vestibular pathology and similar age was utilized.Results: The control group fitted well to the Gaussian distribution.The most persistent symptom was vertigo, followed by hearing loss.One patient had bilateral SSCDS.The latency was higher for cVEMPs at PE but was not disparate for oVEMP latency.In contrast, amplitude was higher at PE than at HE for both tests.Nonetheless, AR was >34% in all oVEMPs, while there were only in two of eight cases for cVEMPs.Conclusion: Though cVEMP abnormalities in amplitude may help to suspect the pathology, oVEMP is the most sensitive and strong test for the diagnosis of SSCDS.This technique is a rapid, reliable, inexpensive test without side effects and thus has a very vital use as a screening and follow-up test in SSCDS.