Vestibular evoked myogenic potentials in peripheral vestibular disorders

Vestibular Evoked Myogenic Potentials are electromyograms of tonic contracted sternocleidomastoid (SCM) muscle which are produced by loud auditory stimulus. VEMP test evaluates the saccule and inferior vestibular nevre function. In our study we intented to assess the value of VEMP testing in the diagnose and differential diagnose of Meniere Disease (MD), Vestibular Neuritis (VN) and Benign Paroxysmal Positional Vertigo Patients. In this study we evaluate the patients records retrospectively who refers to our ENT clinic and who are diagnosed definite MD, VN or BPPV by ENT clinicians from October 2012 to October 2013. Patients' ages are between 20-60. We chose the control group from healthy individuals in the same age range to whom we made VEMP test for the normalization of VEMP results. We assess the 30 ears of 15 patients in the control group, 21 ears of 20 patients in BPPV group, 15 ears of 15 patients in VN group and 27 ears of 21 patients in MD group. As a result of our study we found out that in control group only one ear had prolonged p13 latency whereas other VEMP results were normal in other healthy individuals. In the MD group there were no VEMP responses in 6 effected ear (28,7%), Furthermore, high Asymmetry Ratio (AR) in 4 ears (26,6%), prolonged p13 and/or n23 latency in 8 ears (38,09%) and prolonged interlatency in 3 ears (14,28%) were found. Total 51,8 percentage of the ears had VEMP pathology in MD group. In the VN group there were no VEMP responses in the 2 effected ears (13,33%), high AR in 3 ears (20%), prolonged p13 and/or n23 latency in 4 ears (30,76%) and prolonged interlatency in 3 ears (23,07%) were found. Total 46,66 percentage of the ears had VEMP pathology in the VN group. In the BPPV group there were no VEMP responses in the 2 effected ears (9,52%). Moreover high AR in 2 ears (11,11%), prolonged p13 and/or n23 latency in 5 ears (26,31%) and prolonged interlatency in 3 ears (15,78%) were found. Total 33,33 percentage of the ears had VEMP pathology in the BPPV group. In conclusion practicing VEMP testing in peripheral vestibular disorders is easy to use. If VEMP results are interpreted with the patients' history and physical examination, it will definetly increase the value of the diagnosis of MD, VN and BPPV. In order to understand the benefits of the VEMP testing in these diseases, studies in larger groups in long term should be carried out