Smith T, Trojaborg W
Laboratory of Clinical Neurophysiology, Rigshospitalet, Copenhagen, Denmark.
Arch Neurol. 1987 Nov;44(11):1161-3. doi: 10.1001/archneur.1987.00520230047012.
Ten patients with wasting of hand muscles and sensory symptoms mainly in the ulnar nerve area were diagnosed as having a thoracic outlet syndrome and were operated on for it. Sensory action potentials (SAPs) from digit 5 were reduced in amplitude in eight patients and those from digit 3 in three patients, and the SAP amplitude ratio between digits 3 and 1 was decreased in five patients. Sensory and motor conduction velocity was normal in all. Quantitative electromyographic studies of ulnar and median innervated small hand muscles revealed changes compatible with chronic partial denervation in most patients. The combined findings of chronic partial denervation of the small hand muscles, decreased SAP amplitude from digit 5 and sometimes also from digit 3, and normal motor and sensory conduction velocity are compatible with a compression of the C-8 and T-1 roots or the lower trunk of the brachial plexus.
10例主要表现为手部肌肉萎缩及尺神经区域感觉症状的患者被诊断为胸廓出口综合征并接受了手术治疗。8例患者小指的感觉动作电位（SAPs）波幅降低，3例患者中指的感觉动作电位波幅降低，5例患者中指与示指的SAP波幅比值减小。所有患者的感觉和运动传导速度均正常。对尺神经和正中神经支配的手部小肌肉进行的定量肌电图研究显示，大多数患者存在与慢性部分失神经相符的变化。手部小肌肉慢性部分失神经、小指（有时也包括中指）SAP波幅降低以及运动和感觉传导速度正常这些综合表现，与C8和T1神经根或臂丛下干受压相符。
