Quantitative Evaluation of Biceps Brachii Muscle by Shear Wave Elastography in Stroke Patients.

Purpose: The present study aimed to investigate the differences in muscle size and shear wave speed (SWS) values of biceps brachii muscle (BBM) between stroke survivors and healthy controls.

Methods: This study comprised 61 stroke survivors and 24 healthy subjects, examined at Guangzhou First People's Hospital within one year. Each participant underwent ultrasonic examinations for recording some specific measurement indicators, including muscle thickness, cross-sectional area (CSA), and shear wave speed (SWS) of BBM. The muscular tension of the paretic arm was scored using the modified Ashworth scale (MAS). These above-mentioned indexes were compared between stroke survivors and healthy controls. Also, the correlations among SWS and MAS scores were assessed.

Results: When the lifting arm angle was set for 45°, the CSA and muscle thickness of BBM were obviously decreased in the paretic arms of stroke subjects compared to the non-paretic arms as well as the arms of healthy controls. Moreover, the paretic arms had obviously higher SWS than the non-paretic arms and the healthy arms at 45° or 90°. When the angles of paretic arms were lifted at 90° and 45°, respectively, a positive correlation was established between MAS and SWS.

Conclusion: Ultrasonic examination assessing muscle thickness, CSA, and SWS of the BBM could be used as a means of assessment of the paretic arms of stroke survivors.