Goadsby P J, Burke D
Department of Clinical Neurophysiology, Prince Henry Hospital, Sydney, Australia.
Muscle Nerve. 1994 Jun;17(6):614-22. doi: 10.1002/mus.880170608.
Nerve conduction studies and measurements of thermal thresholds (hot and cold) were performed in 25 healthy control subjects and 24 patients with carpal tunnel syndrome: first, to compare the extent of abnormality demonstrable in the function of large and small afferent axons; second, to correlate these abnormalities with clinical severity; and third, to validate a modified form of palmar stimulation as an additional neurophysiological test in suspected carpal tunnel syndrome. The routine nerve conduction studies compared the amplitudes and conduction velocities from digit II and digit V to wrist and for the digit-II potential between wrist and elbow. With palmar stimulation, the palm-to-wrist segment was compared to the simultaneously evoked antidromic digital potential (palm-to-index). Thermal threshold testing involved determination of hot and cold thresholds for digit II and digit V using an automated forced-choice procedure. In the patients there was selective slowing of conduction across the palm-to-wrist segment with normal velocities distally and proximally, and there was clear evidence of abnormal small-fiber function, with higher thresholds for both hot and cold sensation. However, the thermal abnormalities also involved the ulnar territory, equally so for cold threshold but significantly less so for hot threshold. Thermal threshold testing confirmed the clinical impression that small-fiber dysfunction is important in carpal tunnel syndrome, but the abnormal findings for the ulnar-innervated digit V suggest that this test will not be routinely useful for the early detection of compression or entrapment neuropathies.
对25名健康对照者和24名腕管综合征患者进行了神经传导研究以及热阈值（热觉和冷觉）测量：第一，比较大、小传入轴突功能中可显示的异常程度；第二，将这些异常与临床严重程度相关联；第三，验证改良的掌部刺激作为疑似腕管综合征的一项额外神经生理学检查的有效性。常规神经传导研究比较了从示指和小指到腕部的波幅和传导速度，以及腕部与肘部之间的示指电位。采用掌部刺激时，将掌部至腕部节段与同时诱发的逆向指电位（掌部至示指）进行比较。热阈值测试采用自动强迫选择程序测定示指和小指的热觉和冷觉阈值。患者中，掌部至腕部节段的传导选择性减慢，而远侧和近侧速度正常，并且有明确证据表明存在小纤维功能异常，热觉和冷觉阈值均较高。然而，热觉异常也累及尺神经支配区域，冷觉阈值方面累及程度相同，但热觉阈值方面累及程度明显较轻。热阈值测试证实了临床印象，即小纤维功能障碍在腕管综合征中很重要，但尺神经支配的小指的异常发现表明，这项检查对于早期发现压迫或卡压性神经病通常并无用处。
