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

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.