Thompson M L, Thickbroom G W, Mastaglia F L
Australian Neuromuscular Research Institute, Queen Elizabeth II Medical Centre, Nedlands, WA, Australia.
Brain. 1997 Feb;120 ( Pt 2):245-55. doi: 10.1093/brain/120.2.245.
The topography of the cortical motor projection to the sternocleidomastoid (SCM) muscles was investigated in 15 normal subjects using the technique of transcranial magnetic stimulation. Contrary to the long-held view that the representation of the neck muscles in the motor strip is close to that of the face, our findings indicate that the projection to both the ipsilateral and contralateral SCM muscles arises from an area of cortex high up on the cerebral convexity close to the trunk representation and at a comparable level to the sensory representation of the neck in the post-central cortex. The use of shielded intramuscular recordings showed that surface recordings detect activity not only from the SCM muscle but also from the overlying platysma muscle whose cortical representation is lateral to that of the hand muscles. Our findings confirm that the corticomotor projection to the SCM muscle follows both a contralateral monosynaptic pathway, and an ipsilateral pathway, and indicate that the latter pathway may be disynaptic.
采用经颅磁刺激技术，对15名正常受试者的皮质运动投射至胸锁乳突肌（SCM）的情况进行了研究。长期以来，人们一直认为颈部肌肉在运动皮层的代表区靠近面部，但与这一观点相反，我们的研究结果表明，同侧和对侧SCM肌肉的投射均起源于大脑凸面较高位置的一个皮质区域，该区域靠近躯干代表区，且与中央后回中颈部的感觉代表区处于相当水平。使用屏蔽肌内记录显示，表面记录不仅能检测到SCM肌肉的活动，还能检测到覆盖其上的颈阔肌的活动，颈阔肌的皮质代表区在手肌肉代表区的外侧。我们的研究结果证实，皮质运动投射至SCM肌肉既遵循对侧单突触通路，也遵循同侧通路，并表明后一种通路可能是双突触的。
