Analyses of vestibular cortical responses with Dipole-tracing method and functional near infrared

开发了一种评估前庭刺激对应的脑功能定位的系统。在该系统中，记录并分析了冷热空气对前庭刺激引起眩晕时的脑电图（EEG）和功能近红外光谱（fNIRS）。在冷热刺激2 - 4分钟后，观察到两种典型的血流反应，通过氧化血红蛋白来评估。一种是单纯的脑顶叶和颞叶区血流量增加，另一种是额叶区血流量的两相反应，在前庭刺激后先出现血流量减少，然后在受试者感到眩晕时血流量增加。这些显著的血流反应在脑内非常广泛的区域被观察到，如中央前回、额顶盖、额极、中央后回、边缘上回、顶叶上小叶和颞上回，其定位与以往报道的其他方法评估结果几乎一致。前庭刺激时的脑电图反应表现为θ波爆发，频率分析表明θ波对应的功率谱增加，这可能是由于前庭刺激引起的眩晕引起的脑活动增加。结果表明，同时记录近红外光谱和脑电图可以根据眩晕症状检测大脑皮层的活动，为周围性眩晕疾病的诊断和治疗提供了非常有用的临床信息。

A system to evaluate functional localization in the brain corresponding to the vestibular stimulation was developed. In this system, a electro-encephalogram (EEG) and a functional near infrared spectroscopy (fNIRS) were simultaneously recorded and analyzed during vertigo elicited by the vestibular stimulations, which were made by the cold and hot air.Two characteristic responses of blood flow, evaluated by the oxidized hemoglobin, were observed after the cold and warm caloric stimulation for two to four minutes. One was simple increase of the blood flow, observed in the parietal and temporal area of the brain, the other was two phase response of the blood flow in the frontal area, in which at first the blood flow decreased just after the vestibular stimulation and then it increased when the test subject felt vertigo.These remarkable blood flow responses were observed in very wide area in the brain, such as precentral gyrus, frontoparietal operculum, frontal pole, postcentral gyrus, supramarginal gyrus, superior parietal lobule and superior temporal gyrus, the localization of which almost corresponded to those of the previous reports evaluated by other methods.The EEG responses during the vestibular stimulation indicated a burst of θ-wave and increase of the power spectrum corresponding to the θ-wave by the frequency analysis, which might suggest that the increase of brain activity according to the vertigo elicited by the vestibular stimulation.These results indicated that the simultaneous recording of the fNIRS and EEG could detect the activity of the cerebral cortex according to the vertigo and that our method could provide very useful clinical information for diagnosis and treatment of the peripheral vertiginous diseases.