Assessment of balance and vestibular functions in patients with idiopathic sudden sensorineural hearing loss

This study investigated the relationship among the severity of hearing impairment, vestibular function and balance function in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). A total of 35 ISSNHL patients (including 21 patients with vertigo) were enrolled. All of the patients underwent audiometry, sensory organization test (SOT), caloric test, cervical vestibular-evoked myogenic potential (cVEMP) test and ocular vestibular-evoked myogenic potential (oVEMP) test. Significant relationship was found between vertigo and hearing loss grade (P=0.009), and between SOT VEST grade and hearing loss grade (P=0.001). The abnormal rate of oVEMP test was the highest, followed by the abnormal rates of caloric and cVEMP tests, not only in patients with vertigo but also in those without vertigo. The vestibular end organs were more susceptible to damage in patients with vertigo (compared with patients without vertigo). Significant relationship was found between presence of vertigo and SOT VEST grade (P=0.010). We demonstrated that vestibular end organs may be impaired not only in patients with vertigo but also in patients without vertigo. The cochlear and vestibular impairment could be more serious in patients with vertigo than in those without vertigo. Vertigo does not necessarily bear a causal relationship with the impairment of the vestibular end organs. SOT VEST grade could be used to reflect the presence of vertigo state in the ISSNHL patients. Apart from audiometry, the function of peripheral vestibular end organs and balance function should be evaluated to comprehensively understand ISSNHL. Better assessment of the condition will help us in clinical diagnosis, treatment and prognosis evaluation of ISSNHL.