Fujita T, et al. - Authors evaluated the prevalence of vestibular schwannoma (VS) in patients with sudden sensorineural hearing loss (SSNHL). Findings suggested that in patients with SSNHL, the prevalence of VS was 3.0%. In view of this high prevalence, detailed examinations in addition to audiometry should be considered by the clinicians for patients with SSNHL. Experts did not find the Koos grade IV tumors, which are large tumors that displace the trunk or cranial nerves.