Kanouchi T, Yokota T, Isa F, Ishii K, Senda M
Department of Neurology, Tokyo Medical and Dental University, Bunkyo-ku, Japan.
J Neurol Neurosurg Psychiatry. 1997 Jun;62(6):629-32. doi: 10.1136/jnnp.62.6.629.
The mechanism of mirror movements in two patients was investigated; one with congenital mirror movement, the other with schizencephaly. Transcranial magnetic stimulation on one side elicited motor evoked potentials (MEPs) in their thenar muscles on both sides with almost the same latencies, minimal thresholds, and cortical topographies. During voluntary contraction of the thenar muscle on one side, contralateral transcranial magnetic stimulation induced a silent period not only on the voluntary contraction side but on the mirror movement side and of the same duration. By contrast, ipsilateral transcranial magnetic stimulation elicited MEPs without silent periods in both muscles. With intended unilateral finger movements, an H2(15)O-PET activation study showed that the regional cerebral blood flow increased predominantly in the contralateral sensorimotor cortex, as seen in normal subjects, although mirror movements occurred. It is considered that the ipsilateral motor cortex plays a major part in the generation of mirror movements, which may be induced through the ipsilateral uncrossed corticospinal tract.
对两名患者的镜像运动机制进行了研究；一名患有先天性镜像运动，另一名患有脑裂畸形。对一侧进行经颅磁刺激会在两侧的拇短展肌中引出运动诱发电位（MEP），其潜伏期、最小阈值和皮质地形图几乎相同。在一侧拇短展肌进行自主收缩时，对侧经颅磁刺激不仅在自主收缩侧，而且在镜像运动侧诱发了相同持续时间的静息期。相比之下，同侧经颅磁刺激在两块肌肉中均引出了无静息期的MEP。在进行单侧手指意向性运动时，一项H2(15)O-PET激活研究表明，尽管出现了镜像运动，但区域脑血流主要在对侧感觉运动皮层增加，这与正常受试者的情况相同。据认为，同侧运动皮层在镜像运动的产生中起主要作用，镜像运动可能是通过同侧未交叉的皮质脊髓束诱发的。
