Nighoghossian N, Trouillas P, Vial C, Froment J C
Service de Neurologie, Hôpital Neurologique, Lyon, France.
Stroke. 1995 Feb;26(2):326-8. doi: 10.1161/01.str.26.2.326.
Unilateral upper limb asterixis related to cortical infarct is an unusual clinical picture. We found this association in two patients. Magnetic resonance imaging (MRI), somatosensory evoked potentials (SEPs), and electromyographic recording were performed.
Two patients developed an acute upper limb ataxia with asterixis. This consisted of frequent arrhythmic loss of extensor muscle tone on instruction to maintain the wrist and fingers extended. Voluntary electromyographic activity in the left extensor digitorum communis muscle showed abrupt periods of interruption ranging from 90 to 260 milliseconds in duration in the first case and from 60 to 220 milliseconds in the second case. SEPs were normal. MRI disclosed a right cortical infarct within the primary motor cortex in both cases.
These findings indicate that asterixis was not related to a failure in the processing of proprioceptive input controlling the regulation of postural tone of the distal upper limbs because SEPs were normal. The involvement of primary motor cortex might suggest that asterixis results from an impairment of a centrally generated motor-command signal controlling the postural tone of the distal upper limb.
与皮质梗死相关的单侧上肢扑翼样震颤是一种不常见的临床表现。我们在两名患者中发现了这种关联。进行了磁共振成像（MRI）、体感诱发电位（SEP）和肌电图记录。
两名患者出现急性上肢共济失调伴扑翼样震颤。这表现为在被要求保持手腕和手指伸展时，伸肌肌张力频繁出现无节律性丧失。在第一例中，左侧指总伸肌的自主肌电图活动显示有持续90至260毫秒的突然中断期，在第二例中为60至220毫秒。SEP正常。MRI显示两例患者的初级运动皮层内均有右侧皮质梗死。
这些发现表明，扑翼样震颤与控制上肢远端姿势张力的本体感觉输入处理失败无关，因为SEP正常。初级运动皮层受累可能提示扑翼样震颤是由控制上肢远端姿势张力的中枢产生的运动指令信号受损所致。
