Du Kang, Xu Ke, Cheng Si, Lv He, Zhang Wei, Wang Zhaoxia, Yuan Yun, Meng Lingchao
Department of Neurology, Peking University First Hospital, Beijing, China.
Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
Front Neurol. 2021 Feb 26;12:632096. doi: 10.3389/fneur.2021.632096. eCollection 2021.
Transthyretin familial amyloid polyneuropathy (TTR-FAP) is frequently misdiagnosed as chronic inflammatory demyelinating polyneuropathy (CIDP) because of similar phenotypes in the two diseases. This study was intended to identify the role of nerve ultrasonography in evaluating TTR-FAP and CIDP. Eighteen patients with TTR-FAP, 13 patients with CIDP, and 14 healthy controls (HC) were enrolled in this study. Consecutive ultrasonography scanning was performed in six pairs of nerves of bilateral limbs with 30 sites. The cross-sectional areas (CSAs) and CSA variability data of different groups were calculated and compared. Both TTR-FAP and CIDP showed larger CSAs at most sites of both upper and lower limbs than in HC groups. CIDP patients had larger CSAs than TTR-FAP patients at 8/15 of these sites, especially at U1-3, Sci2 sites ( < 0.01). However, the CSAs at above sites were not a credible index to differentiate TTR-FAP from CIDP with a low area under the curve (<0.8). The CSA variability of median nerves was significantly higher in CIDP than in TTR-FAP and HC groups, with high sensitivity (0.692) and specificity (0.833) to differentiate CIDP from TTR-FAP. The CSA variability of ulnar nerves was not significantly different between the three groups. For the TTR-FAP group, mean CSAs at each site were not correlated with different Coutinho stages, modified polyneuropathy disability, course of sensory motor peripheral neuropathy, Neuropathy Impairment Score, or Norfolk Quality of life-diabetic neuropathy score. The mean compound muscle action potential of ulnar nerves was negatively correlated with the mean CSAs of ulnar nerves. TTR-FAP patients had milder nerve enlargement with less variability in CSAs of median nerves than those with CIDP, suggesting that nerve ultrasound can be a potential useful auxiliary tool to help differentiate the two neuropathies.
转甲状腺素蛋白家族性淀粉样多神经病（TTR-FAP）常因两种疾病的相似表型而被误诊为慢性炎症性脱髓鞘性多发性神经病（CIDP）。本研究旨在确定神经超声在评估TTR-FAP和CIDP中的作用。本研究纳入了18例TTR-FAP患者、13例CIDP患者和14名健康对照者（HC）。对双侧肢体的六对神经共30个部位进行连续超声扫描。计算并比较不同组别的横截面积（CSA）和CSA变异性数据。TTR-FAP和CIDP患者上下肢大多数部位的CSA均大于HC组。在这些部位的15个中有8个部位，CIDP患者的CSA大于TTR-FAP患者，尤其是在U1-3、坐骨神经2部位（<0.01）。然而，上述部位的CSA并非区分TTR-FAP和CIDP的可靠指标，曲线下面积较低（<0.8）。CIDP患者正中神经的CSA变异性显著高于TTR-FAP组和HC组，区分CIDP和TTR-FAP的敏感性高（0.692）、特异性高（0.833）。三组尺神经的CSA变异性无显著差异。对于TTR-FAP组，各部位的平均CSA与不同的库蒂尼奥分期、改良的多发性神经病残疾程度、感觉运动性周围神经病病程、神经病损害评分或诺福克糖尿病性神经病生活质量评分均无相关性。尺神经的平均复合肌肉动作电位与尺神经的平均CSA呈负相关。与CIDP患者相比，TTR-FAP患者的神经增粗较轻，正中神经CSA的变异性较小，这表明神经超声可能是有助于区分这两种神经病的潜在有用辅助工具。
