Does Vestibulo-Ocular Reflex (VOR) Gain Correlate With Radiological Findings in the Semi-Circular Canals in Patients Carrying the p.Pro51Ser (P51S) COCH Variant Causing DFNA9? Relationship Between the Three-Dimensional Video Head Impulse Test (vHIT) and MR/CT Imaging

Abstract

Objective: The primary aim was to determine whether 3D video-head-impulse-test vestibulo-ocular reflex (vHIT VOR)gains correlate with computed tomography (CT) and magnetic resonance (MR) lesions in a series of carriers of the p.(Pro51Ser)-variant (P51S) in the COCH-gene (DFNA9). Secondary aim was to compare routine imaging with second peer review radiologic lecture. Study Design: Analytical cross-sectional study. Setting: Secondary referral center. Patients: Twenty-four p.P51S carriers with MR and CT images. Eighteen carriers were selected of whom both 3D-vHIT and imaging data were available within a time interval of 24 months. Interventions: All imaging data were reassessed by two independent neuroradiologists. vHIT VOR-gains were correlated with semi-circular canal (SCC) lesions. Main Outcome Measures: Correlation between vHIT VORgains and SCC lesions, and additional lesions detected during scientific lecture of imaging data. Results: The average gain of the ipsilateral labyrinth was significantly lower when positive CT (0.3215; p ¼ 0.0122) and MR results (0.3215; p ¼ 0.0134). 92% of ears presented MR lesions on at least one SCC, whereas this was 75% on CT. The posterior SCC is the most frequently affected on MR and CT. Second lecture led to nine additional MR and 16 CT lesions. Conclusions: Significant correlation was observed between radiological lesions at any SCC and lower average gain of the three ipsilateral SCC. The substantially larger number of lesions during scientific assessment stresses the need to fully inform radiologists concerning differential diagnosis to facilitate accurate diagnosis when planning imaging. Focal sclerosis and narrowing of SCC in DFNA9 represent a possible biomarker of advanced stages of otovestibular deterioration.

Pathogenic Variants in the COCH Gene That Lead to Hearing Loss and Vestibular Deficit: Update on DFNA9 and Introducing DFNB110

“…Functional correlations have been observed between fibrous tissue deposits and vestibulo-ocular reflex measurements including caloric response and video head impulse testing. 28,29 Further research is needed to identify the histopathological correlate of these findings and what the implications are, for example, vestibulo-cochlear implantation (CI).…”