KBS
Search
- Page Path
- HOME > Search
Original Articles
- Effects of Changes of Plateau and Rise/Fall Times on Ocular Vestibular Evoked Myogenic Potentials
- Yeo Jin Lee, Soo Hee Han, Eun Jung Ha, Yong Soo Jung, Hi Boong Kwak, Mun Su Park, Jung Eun Shin, Hong Ju Park
- J Korean Bal Soc. 2008;7(2):193-196.
- 1,966 View
- 16 Download
-
Abstract
PDF - Background and Objectives: The ocular vestibular evoked myogenic potential (OVEMP) is a recently discovered test of labyrinthine function, analogous to the cervical VEMP. Recent works have demonstrated the existence of OVEMPs, which likely reflect otolith-ocular reflex. The purpose of this study was to identify the optimal plateau and rise/fall times of short tone bursts to detect OVEMPs in healthy subjects. Materials and Methods: Thirteen healthy subjects (26 ears) were included in this study. Surface electromyographic activity was recorded from active electrodes placed inferior to each eye. Stimulation with 500 Hz short tone bursts was used. We used a variety of plateau and rise/fall times. Three different plateau times (1, 2, and 3 ms) and rise/fall times (0.5, 1, and 2 ms) were used. The incidence, amplitudes and latencies were compared. Results: VEMP responses were clearly observed in all 26 ears at the plateau time of 2 ms and two rise/fall times (0.5 and 1 ms). The amplitudes in the individual ears tested were lower at the rise/fall time of 2 ms than at the other conditions. The amplitudes were lower at the plateau time of 3 ms compared to the other conditions. When the rise/fall time was prolonged from 0.5 to 2 ms, the n1 and p1 latencies were prolonged in parallel. However, there was no such change in latencies according to the plateau times. Conclusions: Our findings show that the ideal stimulation pattern for evoking OVEMP is at the rise/fall times of 0.5 or 1 ms and the plateau time of 2 ms. The waveform morphology of the VEMP responses observed with this stimulation pattern was simultaneously the most constant and marked. Key words: Evoked potentials, Ocular VEMP, Vestibulo-ocular reflex, Otolith
- Assessment of Saccular Function in Patients With Noise Induced Hearing Loss
- In Kuk Hwang, Ji Hyun Moon, Young Hyo Kim, Kyu Sung Kim, Yun Gun Jung, Hoseok Choi
- J Korean Bal Soc. 2008;7(1):17-21.
- 1,851 View
- 7 Download
-
Abstract
PDF
- Background and Objectives: Considering saccular receptors are coupled physically with the auditory receptors, VEMP test may provide the information that in the noise induced hearing loss with or without dizziness, damage to the vestibular system, especially saccule is a potential organ with cochlear damage. Material and Methods: 11 patients (22 ears) with HF-SNHL greater than 55dB and 10 patients (10 ears) with sudden hearing loss of varying degree HL as positive control but without clinical manifestations of vestibular pathology tested for vestibular function test was enrolled. VEMP test was done. The results were compared with those of 9-healthy referents (18 ears) examined in the same way. Results: VEMP wave was significantly abolished as twelve of 22 (54.5%) with HF-SNHL, five of 13 (38.5%) and Control group (100%). Though there was no statistically significant relation with P13, N23 latency delay in each group, NIHL showed P13, N23 latency delay trend compared with controls. Conclusions: Patients with noise induced hearing loss showed significantly more saccular deterioration, estimated as negative VEMP responses than did the controls. This suggests subclinical disturbances of the vestibular system especially of the saccule in noise induced hearing loss.
First
Prev
