Ultrasonographic Evaluation of Respiratory Muscles in Stroke Patients and Its Correlation With Pulmonary Function Tests

Objective This study aimed to evaluate respiratory muscle thickness using ultrasonography (USG) in patients with stroke and to investigate the relationship between respiratory muscle thickness and pulmonary function test (PFT) parameters. Materials and Methods This case-controlled, cross-sectional clinical study included 35 patients with stroke and 35 healthy controls. Diaphragmatic and abdominal muscle thicknesses on the paretic and non-paretic sides in stroke patients, and on the dominant side in healthy participants, were measured using USG. Thickening fractions were calculated, and all participants underwent pulmonary function testing. Results No significant correlation was found between diaphragmatic or rectus abdominis muscle thickness and PFT parameters in patients with stroke ( p > 0.05). Positive correlations were observed between paretic-side external oblique muscle thickness and forced vital capacity (FVC), peak expiratory flow (PEF), and maximal expiratory pressure (MEP). Paretic-side internal oblique (IO) and transversus abdominis muscle thicknesses were positively correlated with MEP ( p < 0.05). On the non-paretic side, IO thickness during maximum forced expiration correlated positively with MEP, while transversus abdominis thickness correlated with FEV 1 /FVC and PEF ( p < 0.05). Conclusion Lateral abdominal muscle thickness was positively correlated with several PFT parameters, particularly MEP, in patients with stroke. Ultrasonographic evaluation of the paretic-side lateral abdominal muscles may play an important role in assessing expiratory muscle strength and monitoring respiratory rehabilitation outcomes in this population.