Detection of skeletal muscle loss by ultrasonography in ischemic stroke patients hospitalized in a neurology intensive care unit and its relationship with plasma c-terminal agrin fragment biomarker

Objectives: Patients with acute ischemic stroke in intensive care units exhibit significant muscle mass loss. This loss affects strength and functional abilities and poses a serious issue due to poor prognosis. Appropriate instruments are needed to document muscle loss in these patients. The primary aim of this study is to observe muscle loss in patients with acute ischemic stroke in our intensive care unit by evaluating the quadriceps femoris muscle using ultrasound. Our secondary aim is to investigate the relationship between skeletal muscle mass loss and plasma C-terminal agrin fragment. Material and Methods: This study included 44 patients who were admitted to the Neurology Intensive Care Unit of Dicle University Faculty of Medicine with a diagnosis of ischemic stroke.Height measurements of all patients were taken using a measuring tape, and their body weights were measured and recorded on the first day of admission, as well as on days 7 and 21. Rectus Femoris (RFM) muscle thickness measurements were performed within the first 24 hours, on the 7th day, and on the 21st day using an ultrasonography (US) device with a 7.5 Megahertz (MHz) transducer probe.Additionally, blood samples were collected on days 7 and 21 to determine serum C-terminal Agrin Fragment (CAF) levels. In this study, the time-dependent changes in RFM thickness and CAF levels, as well as the relationship between changes in RFM thickness and CAF levels on days 7 and 21, were examined. Conclusion: The measurements of right and left RFM thickness in the participants showed a significant decrease on days 0, 7, and 21. The differences in muscle thickness between the three time points for both legs were found to be statistically significant (p<0.001). Plasma CAF levels in the participants demonstrated a significant difference between the measurements taken on day 7 and day 21 (p<0.001). However, while a moderate positive correlation (r: 0.342) was found between the difference in right rectus femoris muscle thickness between the first and second measurements and the change in CAF levels during the same time period, this relationship was not statistically significant for the left rectus femoris muscle (r: 0.152, p>0.05). Similarly, the assessment of the relationship between the average right and left RFM thickness and CAF levels at different time points also revealed similar uncertainties. Results: Our results support that muscle thickness measurements performed by ultrasound may be a reliable non-invasive method for monitoring muscle loss after ischemic stroke, while plasma CAF levels alone may not be sufficient to reflect muscle loss. Therefore, the use of CAF in combination with other biomarkers and clinical parameters for muscle loss assessment may help achieve more accurate results. In the future, comprehensive studies involving larger patient populations and conducted over different time periods may provide more conclusive results regarding the clinical use of these biomarkers. Key Words: Ischemic Stroke, Ultrasonography, Rectus Femoris Muscle Thickness, Muscle Loss, C-terminal Agrin Fragment