冰水刺激诱发前庭性眩晕的功能磁共振研究

The fMRI research of the vestibular vertigo induced by the ice-water

目的:利用功能性磁共振成像技术研究0℃冰水刺激诱导下人类大脑前庭功能相关区域的信号变化。材料与方法:20名健康志愿者作为受试对象,在15s内将15ml的冷水注入受试者右侧外耳道。所有的数据都使用SPM99,对与前庭性眩晕相关的皮质激活区和失活区进行了个体分析及组分析处理。结果:多个皮质及皮质下脑区出现激活及失活。其中激活区包括:辅助运动区、中央旁小叶、左侧楔前叶、左侧后脑岛、左侧颞中回/颞上回复合体及左侧舌状回(BA19区)。失活区包括:双侧额上回及额中回、右侧中央前回、左侧楔前叶及右侧颞中回/颞上回复合体。结论:本实验结果证实人类大脑存在着一个广泛的皮质反应网络参与前庭信号处理过程的学说。

Objective： To study the increase and decrease of MR signal in the functional cortical regions related to the vestibular vertigo with caloric stimulation, 0℃ water, using blood-oxygen level dependent functional MRI （BOLD-fMRI） technique. Materials and Methods： Twenty right-handed human volunteers, 12 males and 8 females, age from 25 to 39 years old, had nothing wrong with the hearing ability and the cavity of the middle ear after the otoscopic examination, the puretone audiometry and the tympanometry tests. They were all examined with a recording electronystagmograph before the fMRI scan to confirm that the caloric stimulus actually induced vestibular vertigo and nystagmus. During the electronystagmograph test, 15ml ice water（0℃） was injected into the right ear of each volunteer within 15s with the subject＇s eyes open. The functional images of brain were acquired with a 1.5T Signa Infinity Twin＋Excite MR system of GE Co. All the subjects were blindfolded with eyes open in a dark circumstance. All data were analyzed on single-subject level and group level using SPM 99. Result： Several cortical and subcortical regions were activated and deactivated. The activated regions included： the supplementary motor area, paracentral lobule, left precuneus lobe, left posterior insula, left MT/MST complex, the cingulum gyrus, left occipital lobe（BA19） and left cerebellum. The deactivated regions included： bilateral superior and middle frontal gyri, right precentral gyrus （BA2/3）, left precuneus lobe, right MT/MST. Conclusion： Cold water stimulation at 0℃ in fMRI confirms a widespread cortical network involved in vestibular signal processing.