Sartucci F, Logi F
Department of Neuroscience, Institute of Neurology, Pisa University Medical School, Pisa, Italy.
Brain Res Bull. 2002 Oct 15;59(1):59-63. doi: 10.1016/s0361-9230(02)00842-0.
Vestibular-evoked myogenic potentials (VEMPs), elicited by acoustic stimulation, have been proposed in the assessment of the vestibulo-cervical reflex pathways. The procedure has been previously validated in several otovestibular disorders. The aim of this study was to investigate patients affected by multiple sclerosis (MS) in the attempt to clarify the underlying physiopathogenetic mechanisms and the clinical utility of VEMPs in detecting vestibulospinal involvement in this disease. VEMPs were obtained according to the technique described by Colebatch and Halmagyi [Neurology 42 (1992) 1635]. We averaged the surface tonic electromyogram from right and left sternocleidomastoid muscle, after bilateral click stimulation (click duration 0.1 ms, repetition rate 3 Hz, intensity 140 dBSPL, 256 stimuli, repeated at least twice). In all cases, we obtained the biphasic, initially positive, p13-n23 wave pattern. P13 peak latency was bilaterally or unilaterally delayed in 8 out of 15 patients (mean delay: 2.2 ms; p < 0.01 on right and <0.05 on left side) and peak-to-peak amplitude significantly reduced (mean amplitude loss: 130 microV; p < 0.01 on right and <0.05 on left side). Their overall diagnostic yield resulted in 60%. In conclusion, the present findings prove that VEMPs are delayed in p13 component and altered in amplitude in MS patients. We hypothesise that these changes might be the result of a conduction impairment in vestibulo-spinal fibres, producing a morphologic alteration of the myogenic responses.
由声刺激诱发的前庭诱发肌源性电位（VEMPs）已被用于评估前庭 - 颈反射通路。该方法先前已在多种耳前庭疾病中得到验证。本研究的目的是调查多发性硬化症（MS）患者，以试图阐明其潜在的病理生理机制以及VEMPs在检测该疾病中前庭脊髓受累情况的临床效用。VEMPs是根据Colebatch和Halmagyi [《神经病学》42（1992）1635] 所描述的技术获得的。在双侧短声刺激后（短声持续时间0.1毫秒，重复率3赫兹，强度140分贝声压级，256次刺激，至少重复两次），我们对左右胸锁乳突肌的表面张力肌电图进行了平均。在所有病例中，我们均获得了双相、起始为正的p13 - n23波形。15例患者中有8例的P13峰潜伏期双侧或单侧延迟（平均延迟：2.2毫秒；右侧p < 0.01，左侧p < 0.05），峰峰值幅度显著降低（平均幅度损失：130微伏；右侧p < 0.01，左侧p < 0.05）。其总体诊断率为60%。总之，目前的研究结果证明，MS患者的VEMPs在p13成分上延迟，幅度发生改变。我们推测这些变化可能是前庭脊髓纤维传导受损的结果，导致肌源性反应的形态改变。
