Photon-counting CT demonstration of acute labyrinthine ischemia in idiopathic sudden sensorineural hearing loss: a case report

The pathophysiology of idiopathic sudden sensorineural hearing loss (ISSNHL) remains unclear. It is widely hypothesized that vascular ischemia, leading to acute labyrinthine ischemia, may represent the most probable underlying etiology. We describe a 51-year-old previously healthy man presenting with acute-onset left-sided hearing loss, tinnitus, and vertigo persisting for 24 h. His clinical features were consistent with acute labyrinthine ischemia, suggesting this as the probable etiology of ISSNHL. Initial photon-counting CT (PCCT) of the inner ear suggested that the branches of the anterior inferior cerebellar artery (AICA) supplying the inner ear, including the labyrinthine artery, were slightly attenuated and exhibited a sparse branching pattern. Follow-up imaging after therapy within a week revealed significant improvement in both the vascular caliber and blood flow. To our knowledge, this case represents the first successful application of PCCT to directly suggest acute labyrinthine ischemia, providing the first reported radiological evidence for this mechanism.