ORIGINAL ARTICLE |
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Year : 2014 | Volume
: 30
| Issue : 2 | Page : 166-170 |
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Effect of age on ocular vestibular-evoked myogenic potentials using air-conducted sound
Samir Asal
Department of Otorhinolaryngology Audiology Unit, Alexandria Petrol Hospital, Faculty of Medicine, Alexandria University, Alexandria, Egypt
Correspondence Address:
Samir Asal Department of Otorhinolaryngology Audiology Unit, Alexandria Petrol Hospital, Faculty of Medicine, Alexandria University, 182 Omar Lofty Street Sporting Tram Station, Alexandria 21111 Egypt
Source of Support: None, Conflict of Interest: None | Check |
DOI: 10.4103/1012-5574.133222
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Rationale/purpose
Diagnostic testing of the vestibular system is an essential component for the correct treatment and rehabilitation of patients with balance dysfunction. Stimulus-related electromyogenic changes can be recorded from the extraocular muscles and is termed ocular vestibular-evoked myogenic potential (oVEMP). These changes are a reflection of the otolith organ functionality. The purpose of this study was to investigate the effect of age on the amplitude, threshold, and latency of the oVEMP, to establish age-appropriate norms that will help in the correct diagnosis of balance dysfunction accordingly.
Participants and methods
This study was carried out in the Audiology Unit of Alexandria Petrol Hospital (Egypt). Participants with no medical history, normal hearing, and who were neurologically free participated in this study. The study was carried out on 50 ears (50 individuals) divided into five groups according to age: the first group from 10 to 25 years, the second group from 25 to 35 years, the third group from 35 to 45 years, the fourth group from 45 to 55 years, and the fifth group over 55 years of age. Each group contained 10 participants.
Results and conclusion
The main outcome measures are amplitude, latency, and threshold of the oVEMP. In this study, oVEMP was present contralaterally in 88% of healthy participants (44 of 50 ears), and the percentage of the presence of oVEMP decreased with age stratification to 60% in the oldest age group (>55 years). When we examined the younger groups in this study, we found 100% response rate for participants under the age of 45 years, whereas the response rate was only 80% in the fourth group (age range, 45-55 years) and 60% in the fifth group (age > 55 years). In the current study, an age effect on oVEMP N1-P1 amplitude and threshold was observed. Significantly reduced amplitude and a significantly increased threshold were observed in the two oldest age groups (>45 years) compared with other age groups. However, oVEMP N1 latency was stable for all age groups less than 55 years but significantly increased in the oldest age group above 55 years. The well-documented neuroanatomic age-related changes that occur in the peripheral vestibular system may explain the commonly reported decrease in the response rate and a decrease in the amplitude with age. However, oVEMP N1 latency represents the function of the time required for the afferent limb of reflex, central transmission and the efferent limb of reflex, and muscle activation. Therefore, the age-dependent increase in N1 latency may occur as a result of degradation of central vestibular system processing, rather than as a result of diminished peripheral vestibular system function. |
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