Skull Vibration-Induced Nystagmus and High Frequency Ocular Vestibular-Evoked Myogenic Potentials in Superior Canal Dehiscence

• Published in: Audiology research (Pavia, Italy) Italy), 2022-04, Vol.12 (2), p.202-211
• Main Authors: Batuecas-Caletrío, Ángel, Jara, Alejandra, Suarez-Vega, Victor Manuel, Marcos-Alonso, Susana, Sánchez-Gómez, Hortensia, Pérez-Fernández, Nicolas
• Format: Article
• Language: English
• Subjects: Audiology; Ears & hearing; Electrodes; Eye movements; Hearing loss; HFoVEMPS; Medical imaging; ocular vestibular-evoked myogenic potentials; Skull; skull vibration-induced nystagmus; Sound; superior canal dehiscence; SVINT; Vertigo; vestibular disorders
• ISSN: 2039-4349; 2039-4330; 2039-4349
• DOI: 10.3390/audiolres12020023

Background: Although diagnostic criteria have been established for superior canal dehiscence syndrome, cases in which the diagnosis is not easy are frequent. On those occasions, some tests such as vibration-induced nystagmus or vestibular-evoked myogenic potentials can offer invaluable help due to their high sensitivity and specificity. Methods: We studied 30 patients showing superior canal dehiscence or “near-dehiscence” in a CT scan. Skull vibration-induced nystagmus and high frequency ocular vestibular-evoked myogenic potentials are performed in each patient. The aim of the study is to determine how useful both tests are for detection of superior canal dehiscence or near-dehiscence. Results: Of the 60 temporal bones studied, no dehiscence was the result in 22, near-dehiscence in 17 and a definite finding in 21. In 10/30 patients, there was no SVIN (Skull vibration induced nystagmus) during otoneurological testing, while in 6/30, induced nystagmus was mainly horizontal, and in 14/30 there was vertical up-beating. All patients had a positive oVEMP (Ocular vestibular evoked myiogenic potentials) at 0.5 kHz in both ears and the HFoVEMP (High frequency ocular vestibular evoked myiogenic potentials) response was positive in 25/60 (41.6%) of the ears studied and in 19/30 of the patients evaluated (in 6 it was positive in both ears). Up-beat SVIN will point to a SCD (Superior Canal Dehiscence) mainly when HFoVEMP are present, and when this is negative there is a high probability that it is not a SCD. Conclusions: When SVIN and HFoVEMP results are added (or combined), they not only improve the possibilities of detecting SCD, but also the affected side.