Nagamine T
Department of Brain Pathophysiology, Kyoto University School of Medicine.
Rinsho Shinkeigaku. 1999 Jan;39(1):42-3.
Precise localization of the current dipole by the magnetoencephalography (MEG) has enabled us to combine the functional information onto the anatomical landmarks. This merit can be best exhibited when the dipole is situated in the superficial cortex and directed parallel to the skull surface. However, before utilizing MEG extensively as a clinical tool, it is inevitable to confirm the precision of the source localization by comparing the estimation with the actual sources. Somatosensory evoked field (SEF) following the electric shock to the peripheral nerve and movement-related cortical field (MRCF) associated with self-paced movement can show us the estimated sources at the postcentral and precentral cortex, respectively, with somatotopic organization. These localizations were confirmed by the direct recordings from the human brain surface during the operation, even if the corresponding areas were anatomically distorted by some lesion occupying the central area. In addition, MEG can localize second somatosensory area (SII) over the superior bank of the Sylvian fissure as well as posterior parietal cortex (PPC), which are difficult to be detected by the EEG recording. These reliable estimation enables us to apply MEG to clarification of pathogenesis of various diseases and source localization for higher brain function.
通过脑磁图（MEG）对电流偶极子进行精确的定位，使我们能够将功能信息整合到解剖学标志上。当偶极子位于浅表皮质且与颅骨表面平行时，这一优点能得到最佳体现。然而，在将MEG广泛用作临床工具之前，通过将估计结果与实际来源进行比较来确认源定位的精度是不可避免的。对周围神经进行电击后的体感诱发电场（SEF）以及与自定节奏运动相关的运动相关皮质场（MRCF），可以分别向我们展示中央后回和中央前回皮质具有躯体定位组织的估计源。即使相应区域因占据中央区域的某些病变而在解剖学上发生扭曲，这些定位也在手术期间通过对人脑表面的直接记录得到了证实。此外，MEG能够在外侧裂上缘以及顶叶后皮质（PPC）定位第二体感区（SII），而脑电图记录很难检测到这些区域。这些可靠的估计使我们能够将MEG应用于阐明各种疾病的发病机制以及高级脑功能的源定位。
