The semicircular canal function tests contribute to identifying unilateral idiopathic sudden sensorineural hearing loss with vertigo.

BACKGROUND: Few studies focused on the prognosis of unilateral idiopathic sudden sensorineural hearing loss (UISSNHL) with vertigo. OBJECTIVES: To describe how the semicircular canal (SCC) function tests may prove helpful in the diagnosis of UISSNHL with vertigo. MATERIAL AND METHODS: 59 UISSNHL patients underwent audiometry, caloric test and video head impulse test (vHIT). The correlation between hearing loss and SCC dysfunction was analyzed. RESULTS: The results showed significant differences of hearing loss grades (p = 0.004) and hearing loss configurations (p = 0.009) between UISSNHL patients with and without vertigo. In vHIT, the gains of horizontal canal (HC) and posterior canal (PC) were more frequently impaired compared with that of anterior canal (AC). The abnormal rate of caloric test was the highest, followed by the abnormal rates of HC and PC gain. A significant difference of abnormal rate of HC gain was only found between the mild and moderate UISSNHL patients with and without vertigo (p = 0.029). CONCLUSION: Abnormal SCC function happens frequently in patients with profound hearing loss. Ipsilesional abnormal vHIT (especially the HC gain) in the presence of abnormal caloric test is a pattern of findings observed in mild and moderate UISSNHL patients with vertigo.