Skull vibration induced nystagmus frequency and location optimization in severe unilateral lesion patients and in anterior canal dehiscences

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• 作者：G. Dumas¹ ; ² ; ^{GDumas@chu-grenoble.fr" class="auth_mail" title="E-mail the corresponding author} ; A. Lion² ; ⁴ ; I.S. Curthoys³ ; P. Perrin² ; ⁵ ; S. Schmerber¹ ; ⁶
• 关键词：Anterior canal dehiscence ; Severe unilateral vestibular lesion ; Skull vibration induced nystagmus ; High frequencies stimulations
• 刊名：Neurophysiologie Clinique / Clinical Neurophysiology
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：46
• 期：4-5
• 页码：255-256
• 全文大小：58 K

文摘

Bone conducted vibrations (BCV) applied on mastoid elicit in common unilateral vestibular lesion (UVL) patients usually a skull vibration induced nystagmus (SVIN) beating toward the intact side and conversely in unilateral superior semicircular canal dehiscence (SCD) a SVIN beating toward the lesion side. Our purpose was to establish optimal topographic and frequency stimulations in severe UVL (SUVL) and SCD patients. The second aim was to compare VIN at 100 Hz in unilateral SCD (uSCD) and bilateral (bSCD) patients.

Participants and methods

The first experiment included 11 SUVL and 10 unilateral SCD (uSCD). The SVIN, optimal frequency was studied with a MiniShaker B&K (10 to 800 Hz) on each mastoid and vertex in SUVL and uSCD; the VIN slow phase velocity (SPV) was recorded with Videonystagmography. Optimal topographic stimulation study analyzed vertex and mastoids responses SPV at 100 Hz. Second experiment included 27 uSCD and 13 bSCD and analyzed SVIN SPV at 100 Hz.

Results

In SUVL, the optimal stimulus frequency was 100 Hz for the horizontal component VIN SPV (P < 0.001). No responses were observed over 500 Hz. In uSCD patients, a wider range of frequency response up to 700 Hz was observed without significant optimal frequency. For the horizontal component VIN, SPV was significantly higher in uSCD than in SUVL at 400 Hz (P = 0.02) and at 600 Hz (P = 0.01); conversely VIN SPV at 100 Hz was higher in SUVL than uSCD (P = 0.008). In SUVL, mastoid stimulation was significantly more efficient than vertex stimulation (ANOVA P = 0.01). Conversely, in uSCD SVIN SPV was significantly higher after vertex stimulation (P = 0.04). A VIN was significantly more often observed in uSCD than bSCD (P = 0.009) and VIN SPV was higher in uSCD than bSCD (P = 0.008).

Conclusion

In SUVL, the optimal frequency stimulation is 100 Hz with no responses over 500 Hz. In SCD, patients responses are observed up to 700 Hz without significant optimal frequency suggesting that the BC facilitation related to the existence of a third window enables a greater sensitivity to higher range of frequencies. Vertex stimulations are more efficient in SCD patients and higher responses are observed in uSCD than bSCD. SVIN acts as a vestibular Weber test.