Changes in Quadriceps Thickness and Echo Intensity in Chronic Stroke Survivors: A 3-Year Longitudinal Study

•Chronic stroke survivors exhibited marked longitudinal changes in skeletal muscles.•Greater deterioration of body weight led to a greater decrease in muscle mass.•Preventing secondary changes in skeletal muscles is essential for stroke survivors. Objectives: The aim of the current study was to examine longitudinal changes in quadriceps muscle mass and intramuscular adipose tissue in chronic stroke survivors. Materials and Methods: In this longitudinal study included 34 chronic stroke survivors who lived in the community. Ultimately, 20 chronic stroke survivors received an after 3-year assessment. Fourteen chronic stroke survivors were lost at follow-up. Chronic stroke survivors who were followed and not followed during 3 years were categorized as follow-up group and lost follow-up group, respectively. The quadriceps muscle mass and intramuscular adipose tissue were assessed at baseline and after 3-year assessments based on muscle thickness and echo intensity in ultrasound images, respectively. Results: No significant differences in any characteristics were observed between the flow-up and lost follow-up groups. In the follow-up group, there was a significant decrease in quadriceps thickness on the paretic (10.3% decrease) and non-paretic (17.0% decrease) sides at follow-up after 3 years compared with baseline. There was a significant increase in quadriceps echo intensity on the paretic (20.0% increase) and non-paretic (24.9% increase) sides at follow-up after 3 years compared with baseline. There were significant positive relationships between changes in body weight and changes in quadriceps thickness on the paretic and non-paretic sides. Chronic stroke survivors with greater reductions in body weight showed a trend towards a greater decrease in quadriceps thickness on the paretic and non-paretic sides. Conclusions: The current results suggest marked longitudinal changes in the skeletal muscles in chronic stroke survivors. Preventing secondary changes in skeletal muscles and limiting decreases in body weight are essential for improving outcomes in chronic stroke survivors.