Evaluation of Ultrasonography as a Screening Tool for Dysphagia in Patients With Stroke: Correlation With Videofluoroscopic Study

For a safe swallowing tongue muscles must function properly and larynx should replace superoanterior to close trachea via stretching cricopharyngeal muscle. In this context, approximation of thyroid cartilage and larynx is important for swallowing. These mechanisms are impaired in stroke, Parkinson's disease, traumatic brain injury, and neuromuscular disorders thus resulting oropharyngeal dysphagia. Clinical examination may be used for assessing dysphagia in those patients however reliability of this method is controversial and videofluoroscopic study is considered as gold standard for assessing dysphagia. Ultrasound is used to assess swallowing functions since 1970s however, the studies commonly focused on tongue thickness and functions. Due to advances in technology besides tongue thickness, ultrasonography may practically demonstrate how larynx and thyroid cartilage approximate and hor larynx moves anteriorly. In literature, three methods came to forefront as evaluation methods for dysphagia: 1) approximation of thyroid cartilage and hyoid bone (THA), 2) tongue thickness in rest (TT), and 3) hyoid bone anterior replacement (HAR). In previous studies, the efficiency of THA for assessing dysphagia via videofluoroscopic study has been demonstrated. However other methods have not been evaluated in dysphagic patients with stroke. Ultrasonography, as a cheap, portable and non-invasive method, is a promising for assessing dysphagia in patients with stroke. In this context, this study aims to test the reliability and efficacy of these three methods via ultrasound in dysphagic stroke patients and test the performance of ultrasound compared to videofluoroscopy.