MR Imaging in Sudden Sensorineural Hearing Loss. Time to Talk

Abstract

Sudden sensorineural hearing loss is defined as acute hearing loss of the sensorineural type of at least 30 dB over 3 contiguous frequencies that occurs within a 72-hour period. Although many different causative factors have been proposed, sudden sensorineural hearing loss is still considered "idiopathic" in 71%-85% of cases, and treatments are empiric, not based on etiology. MR imaging implemented with a 3D FLAIR sequence has provided new insights into the etiology of sudden sensorineural hearing loss. Herein, we review the current management trends for patients with sudden sensorineural hearing loss, from the initial clinical diagnosis to therapeutic strategies and diagnostic work-up. We focused primarily on MR imaging assessment and discuss the relevance that MR imaging findings might have for patient management, pointing out different perspectives for future clinical research.

Fig 1.

Vascular pattern in a 20-year-old woman with left SSHL. Precontrast T1-weighted (A) and precontrast 3D-FLAIR (B) sequences show a high signal in the middle and upper turns of the left cochlea without enhancement on postcontrast T1-weighted (C) and 3D-FLAIR images (D).

Fig 2.

Inflammatory pattern in a 35-year-old man with right SSHL. The precontrast T1-weighted sequence (A) shows no signal abnormalities. The precontrast 3D-FLAIR sequence (B) shows a high signal in the right cranial nerves VII and VIII and in the middle and upper turns of the left cochlea. A postcontrast T1-weighted sequence (C) does not show enhancement, whereas a postcontrast 3D-FLAIR sequence (D) shows the cochlea and cranial nerves VII and VIII as markedly enhanced on the right side.

Fig 3.

Normal MR imaging findings in a 59-year-old man with right SSHL. The precontrast T1-weighted sequence (A) shows spontaneous hyperintense intralabyrinthine fluid in both inner ear structures (arrows), which is symmetric and less evident on the same sequence after contrast injection (B). This hyperintensity is an artifact caused by the altered dynamic range when the fat signal is subtracted, but also reflects an alteration in the visual appearance of signal intensity as the ambient contrast is changed (checker-shadow illusion).