Evaluation of Vestibular Function in Idiopathic Sudden Sensorineural Hearing Loss

Background and ObjectivesZZIt is very important to evaluate vestibular function in patients with sudden sensorineural hearing loss (SNHL) because vertigo combined with sudden SNHL is well known as an important prognostic factor.However, the vestibular function test is not usually performed in sudden SNHL patients without vertigo.We investigated whether different vestibular function tests such as the results of vestibular evoked myogenic potential (VEMP) testing or caloric testing were correlated to prognosis in not only sudden SNHL patients with vertigo but also in sudden SNHL patients without vertigo.Subjects and MethodZZWe enrolled in our study 47 patients with idiopathic sudden SNHL with vertigo or without vertigo.The degree of initial hearing loss was categorized as mild, moderate, moderate-severe, severe, and profound group.Types of initial audiograms were categorized as high tone loss, low tone loss, flat and scale out type.We analyzed the association of the VEMP and caloric test with degree of hearing loss, type of audiogram, and hearing recovery in two month.ResultsZZThe more sever the hearing loss was, the more increased was the rate of abnormal VEMP response (p=0.003).The rate VEMP and caloric abnormality was higher in hearing loss types with high tone loss than in the types with only low tone loss.The rate of accompanying vertigo was high (p=0.017),when the hearing loss was more severe.There was significant correlation between the hearing recovery and vestibular dysfunction (p=0.000,r=0.563).ConclusionZZVEMP and caloric test are useful in evaluating vestibular function and prognosis of sudden SNHL patients.