Predictors of Vertigo in Patients with Untreated Vestibular Schwannoma *Jan Fredrik Andersen, *Kathrin Skorpa Nilsen, *‡Flemming Slinning Vassbotn, *‡Per MLller, †Erling Myrseth, †‡Morten Lund-Johansen, and *Frederik Kragerud Goplen *Departments of Otolaryngology Head and Neck Surgery and ÞNeurosurgery, Haukeland University Hospital, N-5021 Bergen, Norway; and þDepartment of Clinical Medicine, University of Bergen, N-5021 Bergen, Norway Objectives: Previous studies have shown that vertigo is the most powerful negative predictor of quality of life in patients with ves- tibular schwannomas, but the variability in vertigo symptom se- verity is still poorly understood. We wanted to find out whether vertigo could be related to objective parameters such as tumor size, location, vestibular nerve function, hearing, and postural stability in patients with untreated vestibular schwannomas. Study Design: Baseline data from prospective cohort study. Setting: Tertiary referral center. Patients: Four hundred thirty-four consecutive patients with unilateral VS diagnosed on MRI. Mean age 56 years (range 16Y84 yr). Fifty-three percent women. Intervention: Diagnostic, with a medical history, otolaryngo- logical examination, pure-tone and speech audiometry, MRI, posturography, and videonystagmography with bithermal calo- ric tests. Main Outcome Measure: Dizziness measured on a 100-mm visual analog scale (VAS). Secondary outcome measures were canal paresis and postural imbalance (static and dynamic posturography). Results: Three hundred three patients (70%) completed the VAS. Severe dizziness, defined as VAS 75 or greater, was reported by 9% of the patients. Larger tumors were associated with higher risk of postural instability and canal paresis. Moderate to severe dizziness was associated with postural imbalance and canal paresis, and possibly with small to medium-sized tumors. Postural instability was related to tumor size and canal paresis when measured by dynamic, but not with static, posturography. Conclusion: A minority of VS patients experience severe ves- tibular symptoms related to canal paresis and postural instabil- ity. A curvilinear relationship is hypothesized between tumor size and dizziness. Key Words: PosturographyVVertigoVVestibular functionVVestibular schwannoma. Otol Neurotol 00:00Y00, 2014. Vestibular schwannoma (VS) is one of the most well- defined peripheral vestibular disorders, but the remark- able variability in vertigo symptom severity (1) is not completely understood. Most patients present with uni- lateral hearing loss (94%) and tinnitus (83%) (2). Ves- tibular symptoms such as vertigo, nausea, lateropulsion, and nystagmus are often mild, because of slow tumor growth and central compensation, but nevertheless pres- ent in 40 to 75% of the patients at the time of diagnosis (1Y7). A minority of patients report severe vertigo. In a previous study, we showed that, when present, vertigo is the most debilitating symptom with respect to health- related quality of life (8). Lloyd et al. confirmed this finding (9). In a recent study, we found that vertigo in VS patients also represents a risk factor for future work dis- ability (10). VS management has traditionally focused on tumor growth, facial nerve function, and hearing outcomes, whereas outcomes related to vertigo and dizziness are rarely reported. Given the high impact of vestibular symptoms on patients’ quality of life and work dis- ability, there is a need to examine these symptoms more carefully. The primary aim of this study was to find out whether vertigo symptom severity in patients with untreated VS was associated with known objective factors such as tumor size, location, vestibular nerve function, and pos- tural imbalance. Address correspondence and reprint requests to Frederik Kragerud Goplen, M.D., Ph.D., Department of Otolaryngology Head and Neck Surgery, Haukeland University Hospital, N-5021 Bergen, Norway; E-mail: frederik@goplen.net Sources of support: The study was financed by Haukeland University Hospital. There were no external sponsors. The authors disclose no conflicts of interest. Otology & Neurotology 00:00Y00 Ó 2014, Otology & Neurotology, Inc. 1 Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.