Q: Why does a patient with sudden deafness need a cranial MRI (enhancement)? A: Sudden deafness, also known as idiopathic deafness or violent deafness, is a sudden and instantaneous onset of tinnitus and hearing loss of unknown cause, with varying degrees of hearing loss. The deafness can also worsen rapidly within a few hours or days. It mostly affects one ear and has a high incidence in adults aged 40-60 years, with 1% of patients in both ears. According to foreign literature, auditory neuroma is more commonly manifested as sudden deafness than is generally recognized. Some scholars have reported that about 5-10% of patients with auditory neuroma mainly present with sudden deafness. This result is easily overlooked by the physician or patient in the clinical setting. Therefore, in addition to routine otologic examinations, it is essential to perform cranial MRI (with enhancement) in patients with sudden deafness to prevent missed diagnosis and delayed treatment.