Nusret Seher

Background: Carpal tunnel syndrome is rare in the paediatric population but is frequently associated with mucopolysaccharidosis. Owing to nonspecific symptoms and limited reliability of clinical examination, early diagnosis of carpal tunnel syndrome in patients with mucopolysaccharidosis remains challenging. Advanced ultrasonographic techniques may enable objective and early detection. Objective: To evaluate the diagnostic performance of ultra-microangiography and shear wave elastography for the early detection of carpal tunnel syndrome in pediatric patients with mucopolysaccharidosis and to investigate their potential contribution to existing diagnostic protocols. Materials and methods: This cross-sectional study included 44 individuals (mean age, 11.6±4.8 years), comprising 22 pediatric patients with genetically confirmed mucopolysaccharidosis and 22 age- and sex-matched healthy controls. The mucopolysaccharidosis group was further divided into carpal tunnel syndrome–negative ( n =16) and carpal tunnel syndrome–negative ( n =6) subgroups based on electromyography. Median nerve cross-sectional area, vascular index obtained by ultra-microangiography, and stiffness values measured by shear wave elastography (expressed in kilopascals) were evaluated bilaterally. Diagnostic performance was assessed using receiver operating characteristic analysis. Results: Significant differences were observed among control, carpal tunnel syndrome-negative mucopolysaccharidosis, and carpal tunnel syndrome-positive mucopolysaccharidosis groups for median nerve cross-sectional area, vascular index, and stiffness values (all P <0.001). These parameters demonstrated high diagnostic performance in distinguishing mucopolysaccharidosis patients from healthy controls, with area under the curve values ranging from 0.853 to 1.000. Among mucopolysaccharidosis patients, these parameters also demonstrated high accuracy in differentiating carpal tunnel syndrome-positive from carpal tunnel syndrome-negative individuals (AUC, 0.891–0.984), with sensitivity ranging from 83.3% to 100% and specificity from 87.5% to 93.7%. Conclusion: Our findings suggest that ultra-microangiography and shear wave elastography may provide complementary quantitative information for the evaluation of early median nerve changes in pediatric patients with mucopolysaccharidosis, although further studies are required to validate the clinical utility of shear wave elastography in peripheral nerves. Graphical

Background/Objective: Vitamin D plays an important role in musculoskeletal health; however, its association with skeletal muscle microvascular perfusion has not been clearly defined using quantitative imaging techniques. To investigate the relationship between serum 25-hydroxyvitamin D [25(OH)D] levels and skeletal muscle microvascularity using an advanced ultrasound-based microvascular imaging method. Methods: In this cross-sectional study a total of 141 healthy adults were stratified into two groups according to serum 25(OH)D concentration (n = 71; ≥20 ng/mL, n = 70). Ultra-Micro-Angiography was used to quantitatively assess the vascular index (VI), while cross-sectional area (CSA) measurements were obtained for the flexor carpi radialis, biceps brachii, and tibialis anterior muscles. Group comparisons and receiver operating characteristic (ROC) analyses were performed to evaluate the discriminative performance of microvascular parameters. Results: CSA values did not differ significantly between the groups. In contrast, VI values were significantly higher in participants with higher serum 25(OH)D levels across all examined muscles (p < 0.001). Among the evaluated parameters, the biceps brachii VI demonstrated excellent diagnostic performance in distinguishing between groups (AUC = 0.992; optimal cut-off = 1.25). Conclusions: Serum 25(OH)D levels are strongly associated with skeletal muscle microvascularity independent of muscle size. These findings demonstrate a strong association between serum 25-hydroxyvitamin D concentration and skeletal muscle microvascularity and highlight the potential of ultra-micro-angiography as a non-invasive imaging approach for detecting microvascular differences related to vitamin D status.