Feasibility of shear wave elastography to assess upper limb spasticity in patients after brain injury

To assess the feasibility of Shear Wave Elastography (SWE) for quantifying upper limb spasticity in people after brain injury.

This observational study included 52 patients with upper limb spasticity after brain injury. Participants underwent a two-week rehabilitation treatment. The modified Ashworth scale (MAS), upper extremity section of the Fugl-Meyer motor scale (FMMS-UE), Barthel index (BI) and SWE were assessed before and after a two-week rehabilitation. The shear modulus was used to evaluate the stiffness of the biceps brachii at the transverse and longitudinal plane of 0°and 90°elbow flexion.

In our study, paretic side shear modulus values were significantly larger than non-paretic sides (all p-values < 0.05), with significant reductions only on the paretic side (all p-values < 0.001) after 2-week rehabilitation treatment. At baseline, MAS and shear modulus had a significant positive correlation. After rehabilitation, only the longitudinal plane shear modulus showed a correlation with MAS. No significant correlations were found between shear modulus and FMMS-UE or BI scores, except for a negative correlation between shear modulus and BI at 0° transverse plane flexion.

Our findings indicate that SWE effectively quantifies upper limb spasticity and can assess the impact of rehabilitation treatment.