Mehrpour Masoud, Mirzaasgari Zahra, Rohani Mohammad, Safdarian Mahdi
Department of Neurology and Stroke Center, Firoozgar General Hospital, Iran University of Medical Sciences, Tehran, Iran.
Department of Neurology, Rasoul Akram General Hospital, Iran University of Medical Sciences, Tehran, Iran.
Iran J Neurol. 2016 Apr 3;15(2):70-4.
Carpal tunnel syndrome (CTS) is a common peripheral entrapment neuropathy in patients with hypothyroid. The diagnosis of CTS is usually clinical and confirmed by electrodiagnostic (EDX) procedures. This study aimed to describe the diagnostic accuracy of high-resolution ultrasonography (US) as an alternative method to nerve conduction study (NCS) for the diagnosis of subclinical CTS in patients with hypothyroidism.
Between April 2013 and November 2014, from the patients with the diagnosis of hypothyroidism referring to the institute of endocrinology and metabolism of Firoozgar Hospital, Tehran, Iran, those who met our inclusion criteria entered this cross-sectional study. The patients divided into two groups of subclinical CTS with the age- and gender-matched control group. US measurements of the median nerve cross-sectional area (CSA) in the CT inlet were compared with the NCS results as the gold standard diagnostic test.
A total number of 152 wrists of 76 hypothyroid patients were examined in this study. The mean of median nerve CSA at the tunnel inlet was 9.96 ± 2.20 mm(2) for the CTS group and 7.08 ± 1.38 mm(2) for the control group (P < 0.05). 31 wrists (20.4%) were diagnosed as CTS using NCS while US diagnosed 19 wrists (12.5%) as CTS. Using receiver-operating-characteristics analysis, the sensitivity and specificity of US at the diagnosis of CTS were 45.0 and 95.8%, respectively, with a median nerve CSA cutoff point of 9.8 mm(2). Positive and negative predictive values of US were 87.2 and 85.5%, respectively, with a test accuracy of 85.5%.
According to our findings, US has an acceptable diagnostic value to confirm CTS in hypothyroid patients. However, it may not replace NCS due to low sensitivity.
腕管综合征（CTS）是甲状腺功能减退患者常见的周围神经卡压性神经病。CTS的诊断通常基于临床症状，并通过电诊断（EDX）程序进行确诊。本研究旨在描述高分辨率超声（US）作为神经传导研究（NCS）的替代方法，用于诊断甲状腺功能减退患者亚临床CTS的诊断准确性。
在2013年4月至2014年11月期间，从转诊至伊朗德黑兰菲罗兹加尔医院内分泌与代谢研究所的甲状腺功能减退患者中，选取符合纳入标准的患者进入本横断面研究。将患者分为亚临床CTS组和年龄及性别匹配的对照组。将腕管入口处正中神经横截面积（CSA）的超声测量结果与作为金标准诊断测试的NCS结果进行比较。
本研究共检查了76例甲状腺功能减退患者的152只手腕。CTS组腕管入口处正中神经CSA的平均值为9.96±2.20mm²，对照组为7.08±1.38mm²（P<0.05）。使用NCS诊断出31只手腕（20.4%）为CTS，而US诊断出19只手腕（12.5%）为CTS。通过受试者工作特征分析，US诊断CTS的敏感性和特异性分别为45.0%和95.8%，正中神经CSA截断点为9.8mm²。US的阳性预测值和阴性预测值分别为87.2%和85.5%，测试准确性为85.5%。
根据我们的研究结果，US在确诊甲状腺功能减退患者的CTS方面具有可接受的诊断价值。然而，由于敏感性较低，它可能无法取代NCS。
