2.2 Assessment of swallowing
Swallowing assessment was conducted with the modified barium swallow (MBS) study.21 During the MBS, the patient sits upright on a chair or stands on a platform. Thin liquids were administered to subjects with increasing volume (1, 3, 5, and 10 ml), and food items of different consistencies that have been mixed with barium-sulfate–containing products (VaribarĀ®, Bracco Diagnostics Inc., Monroe Twp., NJ) were also administered. The standard lateral radiographic views from the lips to the cervical spine and from the nasopharynx to the upper esophageal sphincter were obtained. We evaluated swallowing performance in each process of the oral (e.g., tongue mobility and mouth residues), pharyngeal (e.g., triggering of pharyngeal swallow, laryngeal elevation and epiglottic closure and nasal regurgitation) and esophageal (e.g., obstruction, passage, and reflux) phases.