Nakamichi Ken-Ichi, Tachibana Shintaro
Department of Orthopaedic Surgery, Toranomon Hospital, 2-2-2 Toranomon, Minato-ku, Tokyo 105-8470, Japan.
Muscle Nerve. 2002 Dec;26(6):798-803. doi: 10.1002/mus.10276.
Severity-correlated enlargement of the median nerve occurs in idiopathic carpal tunnel syndrome (CTS). We determined whether measurement of the nerve cross-sectional area was useful in making the diagnosis of CTS. In 414 wrists of 275 patients with clinically diagnosed idiopathic CTS and 408 wrists of 408 controls, we made ultrasonographic measurements of the nerve area at the distal (distal edge of the flexor retinaculum), mid (hook of the hamate), and proximal carpal tunnel (wrist crease). Criteria based on the area at a single level yielded sensitivities of 43-57% and specificities of 96-97%. Use of the mean carpal nerve area (average of the areas at the three levels) improved the results (sensitivity, 67%; specificity, 97%), which was as sensitive as the nerve conduction studies (NCS). In the NCS, we obtained sensitivities of 66% for the distal motor nerve latency and 67% for the distal sensory nerve latency, with specificities of 97% for each. A combination of the mean carpal nerve area and NCS criteria yielded a sensitivity of 84% and a specificity of 94%. The clinical implications of these findings for the diagnosis of CTS are discussed.
正中神经的严重程度相关增大发生在特发性腕管综合征（CTS）中。我们确定测量神经横截面积是否有助于CTS的诊断。在275例临床诊断为特发性CTS患者的414只手腕以及408例对照的408只手腕中，我们对腕管远端（屈肌支持带远端边缘）、中间（钩骨钩）和近端（腕横纹）的神经面积进行了超声测量。基于单一水平面积的标准，敏感性为43%-57%，特异性为96%-97%。使用腕部神经平均面积（三个水平面积的平均值）改善了结果（敏感性为67%；特异性为97%），与神经传导研究（NCS）一样敏感。在NCS中，远端运动神经潜伏期的敏感性为66%，远端感觉神经潜伏期的敏感性为67%，两者的特异性均为97%。腕部神经平均面积和NCS标准相结合，敏感性为84%，特异性为94%。本文讨论了这些发现对CTS诊断的临床意义。
