Preston D C, Logigian E L
Department of Neurology, Tufts-New England Medical Center, Boston, MA.
Muscle Nerve. 1992 Nov;15(11):1253-7. doi: 10.1002/mus.880151106.
Median motor studies are commonly "normal" in mild carpal tunnel syndrome (CTS). This reflects either the sparing of motor compared to sensory fibers, or the inability of conventional studies to detect an abnormality. A novel approach to demonstrate early motor fiber involvement in CTS is the placement of the same active electrode lateral to the third metacarpal, allowing recording from the second lumbrical or the deeper interossei, when stimulating the median or ulnar nerves at the wrist, respectively. We compared the difference between these latencies in 51 normal control hands to 107 consecutive patient hands referred with symptoms and signs suggestive of CTS, who were subsequently proven to have electrophysiologic CTS by standard nerve conduction criteria. A prolonged lumbrical-interossei latency difference (> 0.4 ms) was found to be a sensitive indicator of CTS in all patient groups. It was also helpful in patients with coexistent polyneuropathy, where localization at the wrist was otherwise difficult.
在轻度腕管综合征（CTS）中，正中神经运动研究通常显示“正常”。这要么反映出运动纤维相对于感觉纤维更不易受累，要么反映出传统研究无法检测到异常。一种用于证明CTS早期运动纤维受累的新方法是，将同一活性电极置于第三掌骨外侧，分别在腕部刺激正中神经或尺神经时，记录来自第二蚓状肌或更深层骨间肌的电信号。我们将51只正常对照手与107只连续的患者手进行了比较，这些患者手因疑似CTS的症状和体征前来就诊，随后根据标准神经传导标准被证实患有电生理CTS。结果发现，所有患者组中，蚓状肌 - 骨间肌潜伏期差异延长（> 0.4毫秒）是CTS的一个敏感指标。这对于同时存在多发性神经病的患者也有帮助，因为在这些患者中，否则很难将病变定位在腕部。
