An imaging study, especially magnetic resonance imaging (MRI), is essential in order to differentiate idiopathic sudden sensorineural hearing loss from acute sensorineural hearing loss of any other etiology. As for MRI modalities to examine a tumor in the internal auditory canal and/or cerebellopontine angle, T1-weighted enhanced and T2-weighted imaging is useful. Recent reports indicate that fluid attenuated inversion recovery (FLAIR) imaging is sensitive in detecting elevated protein levels in fluid. A high intensity signal on FLAIR imaging in the inner ear suggests some pathology of the perilymph and endolymph such as hemorrhage, inflammation, or neoplasm (e.g. a schwannoma). We herein present four cases of acute sensorineural hearing loss with vertigo, which showed abnormal signals in the inner ear on FLAIR imaging and T1-weighted imaging. In all cases, the hearing levels showed no or little improvement despite high dose steroid therapy. These cases indicate the importance of evaluation of FLAIR and T1-weighted imaging in patients with acute sensorineural hearing loss and the possibility of novel etiological concepts of acute sensorineural hearing loss with vertigo established by MRI examinations.
