1Vestibular Research Laboratory, School of Psychology, The University of Sydney, Sydney, New South Wales, Australia; 2MSA ENT Academy Center, Cassino, Frosinone, Italy; and 3Department of Neurology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia.
Ear Hear. 2013 Nov-Dec;34(6):799-805. doi: 10.1097/AUD.0b013e318294e3d2.
The negative potential at 10 msec (called n10) of the ocular vestibular-evoked myogenic potential (oVEMP) recorded beneath the eyes in response to bone-conducted vibration (BCV) delivered to the skull at the midline in the hairline (Fz) is a new indicator of otolithic, and in particular utricular, function. Our aim is to find the optimum combination of frequency and rise-time for BCV stimulation, to improve the sensitivity of oVEMP testing in the clinic.
We tested 10 healthy subjects with 6 msec tone bursts of BCV at three stimulus frequencies, 250, 500, and 750 Hz, at rise-times ranging between 0 and 2 msec. The BCV was delivered at Fz.
The n10 response was significantly larger at the shorter rise-times, being largest at zero rise-time. In addition, we examined the effect of stimulus frequency in these same subjects by delivering 6 msec tone bursts at zero rise-time at a range of frequencies from 50 to 1200 Hz. The main effect of rise-time was significant with shorter rise-times leading to larger n10 responses and the Rise-Time × Frequency interaction was significant so that at low frequencies (100 Hz) shorter rise-times had a modest effect on n10 whereas at high frequencies (750 Hz) shorter rise-times increased n10 amplitude substantially. The main effect of frequency was also significant: The n10 response tended to be larger at lower frequency, being largest between 250 and 500 Hz.
In summary, in this sample of healthy subjects, the most effective stimulus for eliciting oVEMP n10 to BCV at Fz was found to be a tone burst with a rise-time of 0 msec at low stimulus frequency (250 or 500 Hz).
记录在发际线中线的颅骨处（Fz）给予骨导振动（BCV）时，眼睛下方记录的眼前庭诱发肌源性电位（oVEMP）的 10 毫秒负电位（称为 n10）是耳石，特别是椭圆囊功能的新指标。我们的目的是找到最佳的 BCV 刺激频率和上升时间组合，以提高临床 oVEMP 测试的灵敏度。
我们测试了 10 名健康受试者，使用三种刺激频率（250、500 和 750 Hz）的 6 毫秒 Tone Burst BCV，上升时间范围为 0 至 2 毫秒。BCV 在 Fz 处传递。
在较短的上升时间内，n10 反应明显更大，在零上升时间时最大。此外，我们通过在零上升时间以 50 至 1200 Hz 的频率范围在相同的受试者中发送 6 毫秒 Tone Burst 来检查刺激频率的影响。上升时间的主要效应是显著的，较短的上升时间导致更大的 n10 反应，上升时间与频率的相互作用是显著的，因此在低频（100 Hz）时，较短的上升时间对 n10 的影响适度，而在高频（750 Hz）时，较短的上升时间会显著增加 n10 幅度。频率的主要效应也是显著的：n10 反应在较低频率时倾向于更大，在 250 至 500 Hz 之间最大。
总之，在这个健康受试者样本中，在 Fz 处用 0 msec 上升时间的 Tone Burst 在低刺激频率（250 或 500 Hz）下诱发 oVEMP n10 的最有效刺激被发现。
