Response to "Vestibular-evoked myogenic potentials in chronic noise-induced hearing loss"
Journal
Otolaryngology - Head and Neck Surgery
Journal Volume
138
Journal Issue
3
Pages
410
Date Issued
2008-03-01
Author(s)
Abstract
Eye tracking (ET) and optokinetic nystagmus (OKN) tests were included in electronystagmography (ENG) to exclude patients with central vestibular lesions. Those with systemic disorders such as diabetes mellitus or hypertension may show abnormal ET and/or OKN tests. Furthermore, diabetes mellitus or hypertension in chronic noise exposure workers may cause high tone sensorineural hearing loss overlapping on the 4 kHz dip audiogram, consequently, notched audiogram at 4 kHz vanished. Perhaps, the most concern is the aging effect on the vestibular-evoked myogenic potentials (VEMPs). Based on 1000 patients with vestibular disorders, but not on normal controls, Brantberg et al1 suggested that VEMP latency apparently increases with age. However, Welgampola and Colebatch2 studied VEMPs in healthy adults and reported that p13 latency was not significantly correlated with age. Likewise, Su et al3 investigated normal controls and proposed that p13 latency had a trend to prolong as age increased without significant correlation, whereas prolonged n23 latency significantly correlated with advancing age. In our laboratory, multiple logistic regression analysis revealed that n23 latency had a greater odds ratio (8.09) than p13 latency (5.06) in discriminating VEMP latencies between children and adults, which further suggested that n23 latency rather than p13 latency correlates with the advanced age. Control groups were normal healthy subjects who showed normal VEMPs from a large cohort at our laboratory. Statistical analysis between normal and abnormal VEMPs in our patients revealed significant difference indicating that the sample size is reasonable. In addition, our recent animal experiment of noise impact on guinea pigs also confirmed that permanent VEMP loss after noise exposure may reflect permanent threshold shifts in hearing compatible with current clinical results.
Publisher
SAGE PUBLICATIONS LTD
Type
other