Clinical Study Of Using High-frequency Ultrasound Diagnosing Diabetic Polyneuropathy Nerve

Objective:To investigate the width(W)、thickness(T) and cross-sectional area(CSA) changes of media nerve(MN)and ulnar nerve(UN)such as in the “inching test” in patients with type 2 diabetes mellitus(T2DM) with diabetic peripheral neuropathy(DPN)using high-frequency ultrasound and its clinical diagnostic value. Methods:88 diabetic patients and 42 healthy volunteers(Group A) were enrolled in this study. 88 participants were assigned into 2 groups based on characteristic symptoms, signs and nerve conduction study:without DPN(Group B) and with DPN(Group C). The width、thickness and cross-sectional area of the media nerve at 6 points and the ulnar nerve at 8 points were evaluated.Six points on the media nerve include the wrist crease(MN1),pisiform bone level(MN2),hamate bone level(MN3), the 6 cm proximal to the wrist crease(MN4), the 4 cm proximal to tip of the medial epicondyle(MN5) and the midpoint of the humerus(MN6). Eight sites on the ulnar nerve include cubital tunnel(UN1),the 2 cm distal to the medial epicondyle(UN2), the 2 cm proximal to the medial epicondyle(UN3), the 6 cm proximal to the medial epicondyle(UN4), the midpoint of the humerus(UN5), the 8 cm distal to the medial epicondyle(UN6), the 6 cm proximal to the wrist crease(UN7) and Guyon canal(UN8). Receiver operating characteristic(ROC) curve was plotted to determine clinical diagnostic value of the width、thickness and cross-sectional area on different points in diagnosis of DPN.Results:1. A comparison of the MN: ①Comparing with Group A, the width at the wrist crease, hamate bone level and the midpoint of the humerus increased in Group B(P<0.05). The width(P<0.05)except for the 4cm proximal to tip of the medial epicondyle and the midpoint of the humerus larged in DPN patients. Comparing Group B with C, the width at the wrist crease were increased in Group C(P<0.001).②Comparing with Group A, The thickness at the wrist crease and pisiform bone level increased in Group B( P<0.01). The thickness except for the 4 cm distal to the medial epicondyle larged in DPN patients(P<0.05). Comparing Group B with C, The thickness in the midpoint of the humerus were increased in Group C(P<0.001). ③Comparing with Group A, the CSA of all the sites except for the wrist crease increased in Group B(P<0.01). CSAs of all points larged in DPN patients(P<0.001). Comparing Group B with C, CSA except for the 4 cm proximal to the medial epicondyle and the midpoint of the humerus were dramaticlly increased in DPN patients(P<0.001) in Group C.2. A comparison of the UN: ①Comparing with Group A, enlarged width at the 2 cm distal to the medial epicondyle, UN7 and UN8 were showed in Group B(P<0.01). Thickened width except for the 2 cm proximal to the medial epicondyle were showed in Group C(P<0.05). the width at the the 8 cm distal to the medial epicondyle and the midpoint of the humerus were larger in Group C(P<0.05). ②Comparing with Group A, increased thickness in the 2 cm proximal to the medial epicondyle, the 6 cm proximal to the medial epicondyle, the midpoint of the humerus, the 8cm distal to the medial epicondyle and UN8 were showed in Group B(P<0.05). The thickness except for the 2 cm distal to the medial epicondyle were measured in Group C(P<0.05). Comparing Group B with C, the thickness increased only in the 6 cm proximal to the medial epicondyle(P<0.001). ③Comparing with Group A,Thickened CSAs at all sites(P<0.001)were showed in Group B and C. Comparing Group B with C, enlarged CSAs were discovered at the UN1,UN2, the 2 cm proximal to the medial epicondyle, the 6 cm proximal to the medial epicondyle and the midpoint of the humerus(P<0.001).3. A diagnostic value comparison of characteristics of MN and UN in DPN Group :when diagnostic value of the width,thickness and CSA at media nerve different points is the most predictive, the sensitivity is 80.4%,84.8%,84.8% respectively and specificities are all 54.8%. When diagnostic value of the width,thickness and CSA at ulnar nerve all points is the most predictive of DPN, the sensitivity is 84.8%,84.8%,87% respectively and specificity is 52.4%,66.7%,64.3% respectively. Diagnostic value of CSA and the thickness.is superior to the width.The media nerve CSA and the thickness of the hamate bone lever were the most predictive of DPN, with a sensitivity of 84.8% and a specificity of 54.8%. The ulnar nerve CSA of the the 8 cm distal to the medial epicondyle and the thickness of the 6 cm proximal to the medial epicondyle were the most predictive. Conclusion:Peripheral nerves in patients with DPN were decreased to various levels. Upper limb MN and UN backbone and the abnormal changes of different lines can be observed by High-frequency ultrasound which may play a crucial role in the clinical diagnosis of diabetic peripheral nerve.