Ultrasound Assessment of Changes in Muscle Architecture of the Brachialis Muscle After Stroke-A Prospective Study.

Objective: To investigate changes in ultrasound-derived muscle architecture parameters of the brachialis and correlations in patients with subacute stroke. Design: Prospective longitudinal observational study. Setting: Tertiary inpatient rehabilitation center. Participants: Fifty adult patients (N=50) who were recruited within the first month poststroke. The patients had a mean age of 57.2±12.3 years and 68.0% were male. The majority of patients had significant upper limb weakness with a low mean Motricity Index of 18.5±24.7 and median elbow flexor strength of grade 0. Intervention: Not applicable. Main Outcome Measures: Ultrasound of the intact and hemiparetic brachialis was performed at 3-time intervals: within 1 month of stroke onset and at 1 and 6 months after first assessment. Clinical variables captured included upper limb motor power and elbow flexor spasticity. Results: Compared to the intact brachialis, there was reduced muscle thickness (1.93 cm vs 2.07 cm, 1.86 cm vs 2.08 cm, 1.85 cm vs 2.05 cm; Conclusions: Changes including decreased muscle thickness and increased echo intensity of the hemiparetic brachialis were noted over time. Elbow flexor spasticity at 1-month assessment interval appears to mitigate against these changes.