Assessment of Spasticity With Sonoelastography Following Stroke: A Feasibility Study

Objective: To investigate the feasibility of sonoelastography to show muscle stiffness in poststroke spasticity, as well as the relationship between sonoelastography findings and muscle architecture features and clinical spasticity scores in the spastic gastrocnemius. Design: Cross-sectional study. Setting: University rehabilitation center. Participants: A total of 26 stroke patients with gastrocnemius muscle spasticity (>= 1 using the Modified Ashworth Scale score). Interventions: None. Main outcomes: Sonoelastography parameters (elasticity index and elasticity ratio) and muscle architecture features (muscle fascicle length, fascicle pennation angle, muscle thickness and compressibility) were measured from the medial and lateral gastrocnemius muscle on both the affected and unaffected sides. Results: Both the elasticity index and elasticity ratio on the affected side were significantly increased in both the medial and lateral gastrocnemius compared with those on the unaffected side (P < .05). Of the muscle architecture parameters, the compressibility in the medial and lateral gastrocnemius and the fascicle pennation angle in the lateral gastrocnemius were significantly decreased on the affected side (P < .05). There was no significant difference in other parameters between the affected and unaffected side (P > .05). Sonoelastographic findings showed a weak negative correlation with compressibility and a weak positive correlation with the Modified Ashworth Scale score in the spastic medial gastrocnemius. Conclusions: It was found to be feasible to assess stiffness in spastic gastrocnemius muscles of stroke patients with sonoelastography. Further studies are needed to confirm the potential role of sonoelastography to help guide treatment of spasticity and its sequelae.