Audiovestibular Loss of Function Correlates in Vestibular Schwannomas

Abstract

OBJECTIVES:The aim of the present study was to investigate the relationships between tumor size, hearing, and vestibular outcomes in patients with vestibular schwannomas (VSs). MATERIALS and METHODS:Adult patients (n=124) with unilateral extrameatal VS prior to surgery were included in the study. This was a retrospective cohort study of preoperative audiovestibular investigations including audiometry, discrimination test, caloric test, cervical vestibular evoked myogenic potential (c-VEMP), and ocular vestibular evoked myogenic potential (o-VEMP). RESULTS:The difference between lesioned and non-lesioned ear was significant for all audiovestibular outcomes. The mean caloric deficit was 74%. No tumor sided o-VEMPs were elicited. Caloric deficit correlated with hearing loss measured with pure tone average and discrimination score. c-VEMP deficit was significantly associated with severe hearing loss and larger tumors.CONCLUSION: The presence of VS leads to a significant deterioration of audiovestibular function in all objective measures. Caloric test and o-VEMPS are sensitive though unspecific measures of VSs. Increasing tumor size is not directly associated with hearing loss and only somewhat to vestibular deficit. However, audiovestibular findings are correlated.

Current Understanding of Hearing Loss in Sporadic Vestibular Schwannomas: A Systematic Review

“…Intuitively, the larger tumor may lead to severer compression, which will affect their blood supply and lead to neurosensory hearing deficits by subsequent ischemic changes. However, in this systematic review, the majority of the retrieved studies (8/14, 57.1%) suggest the degree of hearing loss do not correlate with tumor size/volume (16)(17)(18)(19)(20)(21)(22)(23). At the beginning of this millennium, Sakamoto et al found no correlation between hearing loss speed and tumor size at the initial diagnosis (16).…”

“…and West et al. further grouped SVS according to the extrameatal diameter (from small SVS <1 cm to giant tumor >4 cm) and found no significant correlation between hearing function and tumor grade ( 21 , 23 ).…”

“…Based on the maximum extrameatal diameter in the axial plane of MRI, Tutar et al distinguished two SVS groups by maximal diameter with one group <20 mm and the other one >20 mm, and they found that there was no significant correlation between the tumor size and the hearing levels in the pure tone audiometry (PTA), speech discrimination scores (SDS), and speech reception thresholds (SRT) (18). Additionally, Lee et al and West et al further grouped SVS according to the extrameatal diameter (from small SVS <1 cm to giant tumor >4 cm) and found no significant correlation between hearing function and tumor grade (21,23).…”

“…Ren, Y (52). 2020 USA23 The expression and activity of MMP-14 in the plasma and tumor secretions correlated with the degree of hearing loss in SVS patients. MMP-14 at physiologic concentrations impaired spiral ganglion neuronal fibers and synapses in cochlear explant cultures.CEA, carcinoembryonic antigen; FGF2, fibroblast growth factor 2; HL, hearing loss; IL-1ß, interleukin-1ß; MMP 14, matrix metalloprotease 14; NLRP3, NLR family pyrin domain containing 3; PEX5L, peroxisomal biogenesis factor 5-like; PSMAL, prostate-specific membrane antigen-like; PTA, pure tone average; RAD54B, RAD54 homolog B; SVS, sporadic vestibular schwannoma; TNFa, tumor necrosis factor alpha.…”

Recent Advances in the Diagnosis of Audio-vestibular DisordersRunning head-Advances in the Diagnosis of Audio-vestibular Disorders

“…The aforementioned test batteries should be performed at the onset of the audiovestibular symptoms and during followup to monitor the course of the disease. The analysis of the relationships between tumour size, hearing, and vestibular outcomes in 124 patients with unilateral extrameatal vestibular schwannoma undergoing preoperative audiovestibular investigations such as audiometry, discrimination test, caloric test, cervical vestibular evoked myogenic potential and ocular vestibular evoked myogenic potential reveals significant a difference between lesioned and non-lesioned ear for all audiovestibular outcomes (6). Cervical vestibular evoked myogenic potential deficit is significantly associated with severe hearing loss and larger tumours.…”