Sudden onset bilateral hearing loss after forehead osteoma removal associated with superior semicircular canal dehiscence.

Sudden sensorineural hearing loss (SNHL) following non-otologic surgery is a rare but potentially devastating complication. We report a case of bilateral SNHL occurring after elective excision of a frontal bone osteoma under general anaesthesia. A 52-year-old woman with no prior hearing impairment developed profound bilateral hearing loss immediately on emergence from anaesthesia, with partial spontaneous improvement over hours and subsequent right-sided predominance with tinnitus. Imaging excluded ischaemic pathology. Audiometry demonstrated a transient bilateral noise-induced pattern, with persistent mild high-frequency SNHL on the right. Further investigation revealed bilateral superior semicircular canal dehiscence (SSCD). We propose that vibrational energy from intraoperative chiselling was abnormally transmitted to the inner ear via a pre-existing "third window" precipitating hearing loss. This case highlights a novel potential mechanism for postoperative SNHL in non-otologic surgery and raises important considerations regarding perioperative risk counselling for procedures involving skull vibration, particularly given the asymptomatic prevalence of SSCD.