Clinical Neurophysiology Laboratory, Department of Neurology, Mount Sinai Medical Center, One Gustave Levy Place, Box 1052, New York, New York 10029, USA.
Muscle Nerve. 2012 Sep;46(3):443-8. doi: 10.1002/mus.23492.
We describe 2 patients who received botulinum toxin A (BoNT) for poststroke spasticity and developed contralateral limb weakness.
Both patients received high doses of BoNT with large dilution volumes and injection in the proximal upper extremity muscles, and developed weakness of the contralateral upper limb. These patients then underwent electrodiagnostic testing of the affected limb.
Repetitive nerve stimulation of the axillary and spinal accessory nerves revealed decrements of 23% and 16%, respectively. EMG revealed abnormal spontaneous activity and small polyphasic motor unit potentials with reduced recruitment. These findings indicated blockade of the neuromuscular junction. Both patients improved.
Isolated weakness of the contralateral limb after BoNT injection for poststroke spasticity suggests diffusion of toxin through tissue planes from proximal upper extremity muscles, across the midline, to contralateral muscles. High doses of botulinum toxin, high dilution volumes, and injection of proximal upper extremity muscles appear to be risk factors for this adverse effect.
我们描述了 2 例接受肉毒毒素 A（BoNT）治疗脑卒中后痉挛的患者，他们出现了对侧肢体无力。
这 2 例患者均接受了高剂量 BoNT 治疗，采用大体积稀释，并在上肢近端肌肉注射，导致对侧上肢无力。这些患者随后对受累肢体进行了电诊断测试。
腋神经和副神经的重复神经刺激分别显示出 23%和 16%的递减。肌电图显示异常的自发性活动和小的多相运动单位电位，募集减少。这些发现表明神经肌肉接头被阻断。这 2 例患者均有改善。
脑卒中后痉挛接受 BoNT 注射治疗后出现对侧肢体孤立性无力提示毒素通过组织平面从上肢近端肌肉扩散，穿过中线到达对侧肌肉。高剂量肉毒毒素、大体积稀释和上肢近端肌肉注射似乎是这种不良反应的危险因素。
