Phongamwong Chanwit, Soponprapakorn Narathorn, Kumnerddee Wipoo
Department of Rehabilitation Medicine, Phramongkutklao Hospital and Phramongkutklao College of Medicine, Bangkok, Thailand.
Ann Rehabil Med. 2017 Aug;41(4):604-609. doi: 10.5535/arm.2017.41.4.604. Epub 2017 Aug 31.
To establish the cutoff value of cross-sectional area (CSA) of the median nerve at the wrist, for determination of electrophysiologically moderate and severe carpal tunnel syndrome (CTS).
The prospective study was conducted among patients suspected of having CTS. A total of 106 patients (185 symptomatic wrists) received nerve conduction study (NCS) and ultrasonography. To establish a cutoff value, various diagnostic properties were calculated across a range of the CSA.
A mean±standard deviation of CSA of the median nerve of normal and mild, moderate and severe CTS was 9.4±2.1, 12.0±2.7, 13.8±4.7, and 15.4±4.1 mm, respectively. The positive relationship between CTS severities and CSA was observed (rs=0.56). A 14 mm CSA had sufficient power to rule in moderate and severe CTS, with a specificity of 91.4% and sensitivity of 42.3%. In addition, it showed a post-test probability (positive predictive value) of 86.3% as against a pre-test probability of 56.2%.
Patients who had ≥14 mm of median nerve CSA had very high probability of moderate to severe CTS.
确定腕部正中神经横截面积（CSA）的截断值，以用于电生理诊断中度和重度腕管综合征（CTS）。
对疑似患有CTS的患者进行前瞻性研究。共有106例患者（185个有症状的手腕）接受了神经传导研究（NCS）和超声检查。为确定截断值，在一系列CSA范围内计算了各种诊断属性。
正常、轻度、中度和重度CTS患者正中神经CSA的平均值±标准差分别为9.4±2.1、12.0±2.7、13.8±4.7和15.4±4.1mm。观察到CTS严重程度与CSA之间呈正相关（rs = 0.56）。CSA为14mm时有足够的能力诊断中度和重度CTS，特异性为91.4%，敏感性为42.3%。此外，其检验后概率（阳性预测值）为86.3%，而检验前概率为56.2%。
正中神经CSA≥14mm的患者发生中度至重度CTS的可能性非常高。
