Sensorineural hearing loss in patients with vestibular schwannoma relies on the presence of utricular hydrops, as diagnosed with heavily weighted T2 sequences

Abstract

Purpose Due to the increased protein concentration in the perilymph liquid, FIESTA-C has recently been proposed to assess endolymphatic spaces without administration of contrast media in patients with vestibular schwannoma. The aim of this study was to assess whether vestibular endolymphatic space dilatation, as evaluated with 3D-FIESTA-C sequences, is related to the degree of hearing loss in patients with schwannoma. Materials and methods In this retrospective study (IRB 5995), we performed 3D-FIESTA-C sequences in 32 patients with schwannoma, as diagnosed on the basis of typical image findings. Two radiologists independently checked the visualization and evaluated the volume of the utricle and saccule. Pearson and Spearman tests were used to explore the correlation between the volume of the tumor, the volume of the vestibular endolymphatic space and the degree of hearing loss – as evaluated with the levels of pure-tone average (PTA) and speech recognition threshold (SRT). Results The endolymphatic space can be evaluated in 72% (23 out of 32 patients) of patients with schwannoma on non-contrast 3D-FIESTA-C sequences. The mean saccular, utricular and tumor volume were 3.17 mm3, 14.55 mm3 and 1.74 cm3 respectively. There was a significant correlation between the volume of the utricle and the degree of hearing loss as evaluated with the levels of PTA (p = 0.015) and SRT (p = 0.004). There was no significant correlation between the saccular and tumor volumes and the degree of hearing loss. Conclusion The volume of the utricle in schwannoma patients is related to the degree of hearing loss.