Ridding M C, Rothwell J C
Medical Research Council Human Movement and Balance Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, U.K.
Can J Physiol Pharmacol. 1995 Feb;73(2):218-22. doi: 10.1139/y95-032.
Transcranial magnetic stimulation over the motor cortex was used to construct a map of the effective sites on the scalp from which short-latency electromyogram responses could be evoked in muscles proximal to either an amputation stump (two subjects) or an ischemically anesthetized forearm (two subjects). At rest, the maps were larger and the responses bigger when stimulating contralateral to the amputated arm or after anesthesia than they were in the intact arm or before anesthesia. However, this difference disappeared when the maps were constructed during a small tonic voluntary contraction of the target muscle. We conclude that reorganisation of the corticospinal projection to a muscle at rest may no longer be present during activity. If so, this calls into question the possible functional benefits of such reorganisation in the control of movement after peripheral damage.
通过对运动皮层进行经颅磁刺激，构建头皮上有效部位的图谱，从这些部位可诱发截肢残端（两名受试者）或缺血麻醉前臂（两名受试者）近端肌肉的短潜伏期肌电图反应。在静息状态下，与截肢臂对侧刺激或麻醉后相比，图谱更大，反应也更大，而在完整手臂或麻醉前则不然。然而，当在目标肌肉进行小幅度紧张性自主收缩时构建图谱，这种差异就消失了。我们得出结论，在静息状态下，皮质脊髓向肌肉的投射重组在活动期间可能不再存在。如果是这样，这就对这种重组在周围损伤后运动控制中可能的功能益处提出了质疑。
