Merello Marcelo, Carpintiero Silvina, Cammarota Angel, Meli Francisco, Leiguarda Ramon
Movement Disorders Section, Raul Carrea Institute for Neurological Research FLENI, Buenos Aires, Argentina.
Mov Disord. 2006 May;21(5):683-9. doi: 10.1002/mds.20736.
A recent prospective analysis on writer's cramp showed that up to 44.6% of patients in a series of 65 presented mirror dystonia, defined as involuntary movements of the resting hand, abnormal posture, tremor, and jerks occurring while writing with the opposite hand. A clinical case is presented, with videotape evidence of right-handed writer's cramp, with mirror movements elicited while writing using either hand. Functional magnetic resonance imaging studies are compared both to those of a normal patient and to those from a patient with writer's cramp but lacking mirror dystonia. Widespread bilateral activation of cortical motor areas contralateral to the mirror movements in patients with writer's cramp and mirror movements suggests, that bilateral activation of the primary motor cortex may account for the appearance of these mirror movements. Further studies need to be conducted to determine whether mirror movements in dystonic patients appear as a result of loss of intra- and/or interhemispheric cortical inhibition or are simply a consequence of the sustained effort these patients need to exert while writing using a dystonic hand.
最近一项关于书写痉挛的前瞻性分析表明，在一组65例患者中，高达44.6%的患者出现镜像性肌张力障碍，其定义为静息手的不自主运动、异常姿势、震颤以及在用对侧手书写时出现的抽搐。本文介绍了一个临床病例，并提供了右手书写痉挛的录像证据，即使用任何一只手书写时均会引发镜像运动。将功能性磁共振成像研究结果与正常患者以及患有书写痉挛但无镜像性肌张力障碍患者的研究结果进行了比较。患有书写痉挛和镜像运动的患者在镜像运动对侧的皮质运动区出现广泛双侧激活，这表明初级运动皮层的双侧激活可能是这些镜像运动出现的原因。需要进一步开展研究，以确定肌张力障碍患者的镜像运动是由于半球内和/或半球间皮质抑制丧失所致，还是仅仅是这些患者在用肌张力障碍的手书写时需要持续用力的结果。
