مقايسه يافته هاي دو آزمون پتانسيل هاي عضلاني برانگيخته دهليزي و كالريك در مبتلايان به كم شنوايي ناشي از نويز و افراد هنجار

Comparison of vestibular evoked myogenic potential and caloric tests findings in noise induced hearing loss-affected and healthy individuals

Background and Aim: Balance disturbance is one of the non-auditory effects of noisy industrial environments that is usually neglected. The aim of the current study was to investigate the effect of occupational noise on vestibular system among workers with noise-induced hearing loss (NIHL), based on both vestibular evoked myogenic potentials (VEMP) and caloric tests. Methods: Thirty male workers with noise-induced hearing loss and thirty male matched controls were examined by VEMP and caloric tests. Study parameters included unilateral weakness, pi3 and n23 latencies, and pl3-n23 amplitude. Caloric test was performed only for 20 patients. Results: No significant difference was observed in unilateral weakness between the two groups. On the other hand, the difference in mean latencies of pl3 in the right ear (p=0.003) and left ear (p=0.01) was significant between the two groups. However, the difference in n23 latency was significant only in the right ear (p=0.03). There was no significant difference between groups in pl3-n23 amplitude. Conclusion: It seems that pars inferior of vestibule is the susceptible part in individuals with NIHL. In general, abnormal findings in both VEMP and caloric tests were more common compared to functional symptoms such as vertigo, which may be due to central compensation and the symmetry of the disorder.