Somatic motor and sensory representation in the cerebral cortex of man as studied by magnetoencephalography and transcranial magnetic stimulation.

目的penfield报道了人脑感觉和运动表征的皮层图。在这些地图中，大部分身体部位都是穿过中央沟相互面对的，只有颈部在运动和感觉皮层中是分开的，即在运动皮层中位于手指和面部之间，在感觉皮层中位于手指内侧。我们认为这一事实与局灶性肌张力障碍的机制有关，如痉挛性斜颈和感觉欺骗。作为阐明这一临床问题的第一步，我们利用脑磁图（MEG）和经颅磁刺激（TMS）对手指、面部和颈部的运动和感觉皮层进行了评估。脑磁图和经颅磁刺激是一种可以无创评估人脑功能的新仪器。5名健康受试者参加经颅磁刺激试验。我们利用经颅磁刺激的一分区映射来评估他们手指、面部和颈部的运动区位置。我们记录了受试者第一背骨间肌（手指）、口轮匝肌（面部）和胸锁乳突肌（颈部）的运动诱发电位（MEPs）。结果表明，运动皮层的手指区和面部区分别位于距顶点外侧约5cm和9cm处，颈部区分别位于距顶点外侧约3cm和7cm处。我们的研究结果表明，运动皮质的颈部区存在于与颈部和感觉皮质躯干区相邻的躯干区附近，以及Penfield报道的手指和面部之间。对10名健康受试者进行脑磁图研究，记录了电刺激腕部正中神经、手指皮肤和大鱼际肌运动点后的体感诱发磁场。在正中神经刺激后约20ms、30ms、40ms、60ms出现4个SEF峰，在手指刺激后约20ms、30ms出现2个SEF峰，在约60ms出现1个SEF峰。这些峰值的等效电流偶极子都在初级感觉皮层的手部区域附近。

PurposePenfield reported cortical maps of sensory and motor representation in human brain. In these maps, most of body parts faced each other across central sulcus, but only neck was located separately in motor and sensory cortex, i.e. between finger and face in motor cortex and medial to finger in sensory cortex. We thought that this fact was associated with mechanism of focal dystonia, such as spasmodic torticollis, and sensory trick. As the first step to elucidate such a clinical question, we evaluated motor and sensory cortex of finger, face and neck by magnetoencephalography (MEG) and transcranial magnetic stimulation (TMS). The MEG and TMS are new devices that can evaluate human brain function noninvasively.A TMS studyFive healthy subjects were participated. We evaluated the locations of their motor area of finger, face and neck used by one-divisional mapping of TMS. We recorded motor evoked potentials (MEPs) of subjects from first dorsal interosseis (finger), musculus orbicularis oris (face) and sternocleidomastoideus (neck). As a result, the finger and face area of motor cortex were located in about 5cm and 9cm lateral from vertex respectively, while the neck area was exist in about both 3cm and 7cm lateral to vertex, separately. Our results suggested that the neck area of motor cortex existed near the trunk area which faced the neck and trunk area of sensory cortex, as well as between finger and face area which reported by Penfield.A MEG studySomatosensory evoked magneticfields (SEF) were recorded in ten healthy subjects following to electrical stimulation of median nerve at wrist, skin of finger and motor point of thenar muscle. There were four peaks of SEF at about 20ms, 30ms, 40ms and 60ms after median nerve stimulation, two peaks at about 20ms and 30ms after finger stimulation, and a peak at about 60ms. The equivalent current dipoles of these peaks were all near the hand area of the primary sensory cortex.