Vestibular Evoked Myogenic Potentials in Normals and in Individuals with Dizziness

Abstract

The present study aimed at investigating VEM P in individuals with or without dizziness for click at 99 dBnHL and STB at 99 dBnHL and 105 dBnHL. Control group was divided into two subgroups, A and B. ABR test was carried out to check for the space occupying lesion. Results showed that p12 and n23 latency and peak to peak amplitude was approximately the same in group A and group E. As the intensity increased the peak to peak amplitude increased but the latency remained constant in both control and experimental group. Compared to normal group the experimental group subjects had prolonged mean latency and reduced peak-to-peak amplitude. It was observed that latencies with STB VEM P were longer than click evoked VEMP. Further, STB VEMP amplitude was longer than that of click evoked VEMP. The difference in response elecited by 105 dBnH L STB and 99 dEnHL STB or 99 dBnHL clicks was negligible in normals. The subjects who showed signs of vestibular symptoms such as "objects spinning or turning around you" showed either absent or abnormal VEMP responses. From the results it can be concluded that there will not be any change in VEMPs in age from 21 to 40 year. STB can be used at maximum intensity to check for VEMPs as the percentage of VEM P response increased from 94% to approximately 97% from 99 dBnHL to 105 dBnHL in normals. It can also be concluded that abnormal VEMPs can be associated with symptoms such as objects spinning or turning around, tendency to fall, loss of balance when walking and nausea or vomiting. Thus, it can be concluded that the subjects who complain these symptoms are likely to have saccular pathway lesion.