Inner Ear Schwannoma Treated With Intratympanic Gentamicin for Recurrent Ménière's Disease-Like Vertigo: A Case Report.

Inner ear schwannoma (IES), also known as intralabyrinthine schwannoma, is a rare benign tumor typically presenting with hearing loss, tinnitus, and vestibular symptoms. In some cases, vestibular manifestations mimic Ménière's disease, characterized by recurrent vertigo attacks in which endolymphatic hydrops has been implicated in the underlying pathophysiology. Herein, we report the case of a 44-year-old woman with left-sided IES who developed intractable recurrent vertigo. Despite profound hearing loss in the affected ear, vestibular function testing revealed residual activity in all three semicircular canals on the affected side. Contrast-enhanced magnetic resonance imaging demonstrated a tumor occupying nearly the entire cochlea and partially extending into the vestibule, while no definite endolymphatic hydrops was identified. Medical therapy was ineffective in controlling the vertigo attacks. The patient underwent repeated intratympanic gentamicin (GM) injections. After the fifth session, she experienced transient severe vertigo followed by complete resolution of recurrent vertigo attacks. Follow-up testing demonstrated further reductions in vestibulo-ocular reflex gains in all three semicircular canals on the affected side, while contralateral vestibular function remained preserved. No recurrent vertigo attacks occurred during the two-year follow-up period. This case suggests that intratympanic GM may represent a non-surgical treatment option for selected patients with IES-related refractory vertigo.