Shear Wave Elastography of the Tibial Nerve and Lower Limb Nerve-Muscle-Tendon Complex in Diabetic Peripheral Neuropathy: Elastic Alterations and Clinical Implications.

Abstract

Objectives: To investigate the associations among diabetic peripheral neuropathy (DPN), diabetic tendinopathy, and diabetic myopathy and their respective influencing factors using shear wave elastography (SWE).

Methods: This study enrolled 65 diabetic patients (22 with DPN [PN-DM group], 43 without DPN [NPN-DM group]) and 35 healthy controls. Their general clinical data and laboratory indicators were collected. High-resolution ultrasound and SWE evaluated the morphology and elasticity of the tibial nerve (TN), Achilles tendon (AT), and medial head of gastrocnemius (MG). Parameters were compared among 3 groups.

Results: Diabetic patients exhibited larger cross-sectional area (CSA) and transverse diameter (TD) of the TN than controls (all p < .05). Longitudinal TN shear wave velocity (SWV) progressively increased from controls to NPN-DM to PN-DM groups. The right TN Emax (cutoff: 3.87 m/s) demonstrated the highest diagnostic accuracy for DPN, with 90.9% sensitivity and 61.8% specificity. Diabetic patients displayed significantly reduced cross-sectional AT SWV, as well as lower absolute difference in pennation angle and SWV of the MG than controls (p < .01). The AT's SWV and MG's ΔSWV correlated positively (p < .001), but neither correlated with TN's SWV. HbA1c was independently associated with all 3 structures' elasticity (p < .05).

Conclusions: TN's SWV increased significantly from the control to NPN-DM, and further to the PN-DM group. AT and MG's elasticity decreased significantly in diabetic patients with a positive correlation, but neither correlated with TN's elasticity. HbA1c was the solely independent risk factor common to the TN, AT, and MG elasticity.