Vestibular Schwannoma Presenting as Acute Vertigo Mimicking Vestibular Neuritis.

Vestibular schwannoma (VS) is commonly accompanied by hearing loss, tinnitus, and dizziness and tends to be chronically progressive in nature. We report a case of VS presenting as left vestibular neuritis (VN) in a previously healthy 57-year-old patient. Right-beating horizontal-torsional spontaneous nystagmus was observed, and the bedside head impulse test revealed a left catch-up saccade. The bithermal caloric test showed left canal paresis, and pure-tone audiometry revealed an average threshold of 22.5 dB bilaterally. Brain magnetic resonance imaging (MRI) demonstrated a 0.7-cm enhancing mass in the left internal auditory canal, consistent with VS. The patient was administered with high-dose systemic corticosteroids and vestibular suppressants with antiemetic, which relieved acute vertigo. Although dizziness in VS is chronically progressive in nature, VS may present as an acute vestibular syndrome that mimics VN. VS should be considered a potential cause of acute vestibular syndrome, and thorough neurological examination with MRI may be helpful for accurate diagnosis.