应用磁源性影像对健康青年人大脑听觉皮层功能区定位的初步研究  

Preliminary study on the functional localization of auditory cortex in the healthy young subjects using magnetic source imaging

作　　者：苗英章[1] 孙吉林[2] 步桂清[1] 荣宏[1] 吴杰[2] 李素敏[2] 梁恒仁[1] 

机构地区：[1]河北省人民医院耳鼻咽喉科,石家庄050051 [2]河北省人民医院医学影像中心,石家庄050051

出　　处：《中华耳鼻咽喉科杂志》2004年第5期288-292,共5页Chinese Journal of Otorhinolaryngology

基　　金：河北省科技厅科技攻关项目 ( 0 2 2 7610 2D 2 )

摘　　要：目的　探讨磁源性影像在大脑听觉皮层功能区定位的应用价值。方法　应用全头型30 6通道生物磁仪 ,对 30例健康青年人 (2 0～ 32岁 )男 16例 ,女 14例进行了大脑听皮层诱发磁场的测试 ,5例观察了 0 5、1、2、4、8kHz纯音诱发的脑磁反应波M10 0 ,另 2 5例均测试了 2kHz纯音诱发的脑磁反应波M10 0 ,并将脑磁图的电生理资料与磁共振成像的解剖结构资料叠加 ,获得大脑听觉皮层磁源性影像 ,以确定M10 0在大脑初级听觉皮层的位置。结果　 30例受试者均可诱发出M10 0 ,且重复性好 ,其位置均位于大脑的颞横回 ;不同频率的纯音诱发的M10 0在大脑颞横回有其各自的定位和分布 ;初级听觉皮层在两侧大脑半球的位置相对而言左侧靠后 ,右侧靠前 ,两侧明显不对称。M10 0潜伏期在左侧和右侧大脑半球对侧声刺激均较同侧声刺激为短 ,但M10 0等电流偶极的位置与刺激声的侧别无关。结论　由脑磁图的M10 0所获得的磁源性影像 ,具有良好的时间和空间分辨率 ,可对大脑初级听皮层功能区进行精确定位 ,将在耳科学的临床和基础研究中具有广阔的应用前景。Objective To evaluate the value of magnetic source imaging (MSI) in the functional localization of the primary auditory cortex. Methods The M100 waves of cortical auditory evoked magnetic fields (AEFs) evoked by 0.5、1、2、4 and 8 kHz pure tones in 5 subjects and by 2 kHz pure tones in 25 healthy young subjects were measured respectively (16 males and 14 females, with the age from 20 to 32 years old) using a whole head 306 channel magnetoencephalography (MEG) system. The MSI obtained by superimposing functional MEG data on structural magnetic resonance image (MRI) was used to localize the M100 sources on the auditory cortex. Results The M100 waves of AEFs were clear and replicable in both hemispheres. The M100 sources were localized on the bilateral transverse temporal gyri in all 30 subjects. The localization of M100 on transverse temporal gyri varied with the changes of stimulus frequency. The localization of primary auditory cortex was asymmetrical between bilateral hemispheres, and the left hemisphere M100 dipoles were significantly posterior compared to the right M100 dipoles. The M100 responses appeared significantly earlier to the contralateral stimuli than that to the ipsilateral stimuli in both hemispheres. The dipole positions of M100 were independent of the side of the stimuli. Conclusions The functional localization of the primary auditory cortex could be determined precisely by magnetic source imaging (MSI) with high spatiotemporal resolution. MSI would hold great promise as a noninvasive tool for the fundamental and clinical research in otology.

关 键 词：磁源性影像 健康青年人 大脑听觉皮层 脑磁图描记术 磁共振成像 

分 类 号：R741.04[医药卫生—神经病学与精神病学]