Unusual acute hearing loss after gamma knife surgery for a facial schwannoma.

A 34-year-old female patient suffering from right-sided facial palsy presented to our hospital. Her hearing range was within normal limits. She had undergone GKS after receiving a diagnosis of facial nerve schwannoma (FNS). On the fourth day after GKS, the patient experienced sudden onset hearing loss on the right side without aggravation of the facial palsy. Intravenous corticosteroids were administered, and her hearing function improved gradually over the course of 15 days. This is the first case report of hyperacute hearing loss after GKS for FNS.