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

Volume 4 - Issue 4

Esmeralda Rocío Martín^1,3, Lorena Vega Zelaya^1,3, Laura López Viñas¹, Salvador Delis Gómez¹, Yvonne López Castanier² and Jesús Pastor^1,3*

Received: June 25, 2020;   Published: July 09, 2020

DOI: 10.32474/SJO.2020.04.000193

Full Text PDF

To view the Full Article   Peer-reviewed Article PDF

Abstract

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.

Keywords: cVEMP; Clinical Neurophysiology; Hearing loss; Nystagmus; oVEMPs; Vertigo; Vestibular disorders

Abbreviations: AR: Asymmetry Ratio; CT = Computed Tomography; IOM: Inferior Oblique Muscle; cVEMP: Cervical Vestibular Evoked Myogenic Potentials; HE: Healthy Ear; nHL: Normal Hearing Level; oVEMP: Ocular Vestibular Evoked Myogenic Potentials; PE: Pathological Ear; SCM: Sternocleidomastoid Muscle; SSCDS: Superior Semicircular Canal Dehiscence Syndrome; VEMP: Vestibular Evoked Myogenic Potentials

Abstract| Introduction| Materials and Methods| Results| Discussion| Conflict of Interests| Funding| References|