Vestibular neuronitis in a vestibular schwannoma patient.

This is a unique presentation of an acute vestibular syndrome (AVS) caused by vestibular neuronitis (VN) of a vestibular nerve (CNVIII) already affected by vestibular schwannoma (VS). A 48-year-old patient, formerly diagnosed with an intracanalicular VS, presented with AVS. The patient underwent clinical and neurotological examination including video Head Impulse Test and a 4-hour delayed-enhanced 3D-FLAIR MRI using intravenous gadolinium. Clinical and neurotological findings were consistent with VN of the CNVIII formerly diagnosed with VS. A 4-hour delayed-enhanced 3D-FLAIR MRI showed significant enhancement of the labyrinth also indicating VN of the same nerve affected by VS. Pragmatic corticosteroid therapy and vestibular exercises were applied resulting in satisfactory recovery of the patient. As vestibular symptoms are common in VS patients, investigating another cause of dizziness and vertigo in VS patients can be marginalized. Nevertheless, VS presenting as AVS is very unusual. VN should not be overlooked as a possible cause of acute vertigo in a patient previously diagnosed with VS.