Uncini A, Lange D J, Solomon M, Soliven B, Meer J, Lovelace R E
Columbia Presbyterian Medical Center, Department of Neurology, College of Physicians and Surgeons of Columbia University, New York, NY.
Muscle Nerve. 1989 Sep;12(9):735-41. doi: 10.1002/mus.880120906.
Because digit 4 (D4) has dual innervation, median and ulnar sensory latencies can be determined over identical distances. To determine if D4 testing is more sensitive than other commonly used techniques to diagnose carpal tunnel syndrome (CTS), we examined 42 hands with clinical evidence of carpal tunnel syndrome and 43 control hands. D4 latency was significantly longer than controls more often than digit 2 (D2) in patients with CTS. Comparing median to ulnar latencies from D4 was the most sensitive method to make the diagnosis of CTS. In mild CTS, a characteristic double peak potential was seen in recordings from the median nerve after stimulating D4. This potential provided immediate visual confirmation of the diagnosis of CTS. Comparing D4 latency along median and ulnar nerves is useful for detecting mild CTS and should be used whenever there are clinical signs and symptoms of CTS but electrodiagnostic studies are normal or borderline.
由于第4指（D4）具有双重神经支配，因此可以在相同距离上测定正中神经和尺神经的感觉潜伏期。为了确定D4测试在诊断腕管综合征（CTS）方面是否比其他常用技术更敏感，我们检查了42只具有腕管综合征临床证据的手和43只对照手。在患有CTS的患者中，D4潜伏期比对照明显延长的情况比第2指（D2）更常见。比较来自D4的正中神经与尺神经潜伏期是诊断CTS最敏感的方法。在轻度CTS中，刺激D4后正中神经记录中可见特征性的双峰电位。该电位为CTS的诊断提供了直接的视觉确认。比较沿正中神经和尺神经的D4潜伏期有助于检测轻度CTS，并且每当有CTS的临床体征和症状但电诊断研究正常或处于临界状态时都应使用。
