Long-term Effects of Conservative Management of Vestibular Schwannoma on Dizziness, Balance, and Caloric Function.

Abstract

To study the development of dizziness, caloric function, and postural sway during long-term observation of untreated vestibular schwannoma patients. Retrospective review of a prospectively maintained longitudinal cohort. Tertiary referral hospital. Patients with vestibular schwannoma undergoing wait-and-scan management were included-specifically, those who did not require treatment during a minimum radiologic follow-up of 1 year. Baseline data and follow-up included magnetic resonance imaging, posturography, bithermal caloric tests, and a dizziness questionnaire. Main outcomes were prevalence of moderate to severe dizziness, canal paresis, and postural instability at baseline and follow-up, as compared with McNemar's test. Out of 433 consecutive patients with vestibular schwannoma, 114 did not require treatment during follow-up and were included. Median radiologic follow-up was 10.2 years (interquartile range, 4.5 years). Age ranged from 31 to 78 years (mean, 59 years; SD, 10 years; 62% women). Median tumor volume at baseline was 139 mm³ (interquartile range, 314 mm³). This did not change during follow-up (<i>P</i> = .446). Moderate to severe dizziness was present in 27% at baseline and 19% at follow-up (<i>P</i> = .077). Postural unsteadiness was present in 17% at baseline and 21% at follow-up (<i>P</i> = .424). Canal paresis was present in 51% at baseline and 56% at follow-up (<i>P</i> = .664). There was no significant change in the prevalence of dizziness, postural sway, or canal paresis during conservative management of vestibular schwannoma, while tumor volume remained unchanged. This indicates a favorable prognosis in these patients with regard to vestibular symptoms.